Impact Assessment and Environmental Evaluation of Various Ammonia Production Processes.

PubMed

Bicer, Yusuf; Dincer, Ibrahim; Vezina, Greg; Raso, Frank

2017-05-01

In the current study, conventional resources-based ammonia generation routes are comparatively studied through a comprehensive life cycle assessment. The selected ammonia generation options range from mostly used steam methane reforming to partial oxidation of heavy oil. The chosen ammonia synthesis process is the most common commercially available Haber-Bosch process. The essential energy input for the methods are used from various conventional resources such as coal, nuclear, natural gas and heavy oil. Using the life cycle assessment methodology, the environmental impacts of selected methods are identified and quantified from cradle to gate. The life cycle assessment outcomes of the conventional resources based ammonia production routes show that nuclear electrolysis-based ammonia generation method yields the lowest global warming and climate change impacts while the coal-based electrolysis options bring higher environmental problems. The calculated greenhouse gas emission from nuclear-based electrolysis is 0.48 kg CO 2 equivalent while it is 13.6 kg CO 2 per kg of ammonia for coal-based electrolysis method.

LARGE-SCALE HYDROGEN PRODUCTION FROM NUCLEAR ENERGY USING HIGH TEMPERATURE ELECTROLYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

James E. O'Brien

2010-08-01

Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demandmore » for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a “hydrogen economy.” The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.« less

Final Technical Report, Oct 2004 - Nov. 2006, High Performance Flexible Reversible Solid Oxide Fuel Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, Jie; Minh, Nguyen

This report summarizes the work performed for the program entitled “High Performance Flexible Reversible Solid Oxide Fuel Cell” under Cooperative Agreement DE-FC36-04GO14351 for the U. S. Department of Energy. The overall objective of this project is to demonstrate a single modular stack that generates electricity from a variety of fuels (hydrogen and other fuels such as biomass, distributed natural gas, etc.) and when operated in the reverse mode, produces hydrogen from steam. This project has evaluated and selected baseline cell materials, developed a set of materials for oxygen and hydrogen electrodes, and optimized electrode microstructures for reversible solid oxide fuelmore » cells (RSOFCs); and demonstrated the feasibility and operation of a RSOFC multi-cell stack. A 10-cell reversible SOFC stack was operated over 1000 hours alternating between fuel cell (with hydrogen and methane as fuel) and steam electrolysis modes. The stack ran very successfully with high power density of 480 mW/cm2 at 0.7V and 80% fuel utilization in fuel cell mode and >6 SLPM hydrogen production in steam electrolysis mode using about 1.1 kW electrical power. The hydrogen generation is equivalent to a specific capability of 2.59 Nm3/m2 with electrical energy demand of 3 kWh/Nm3. The performance stability in electrolysis mode was improved vastly during the program with a degradation rate reduction from 8000 to 200 mohm-cm2/1000 hrs. This was accomplished by increasing the activity and improving microstructure of the oxygen electrode. Both cost estimate and technology assessment were conducted. Besides the flexibility running under both fuel cell mode and electrolysis mode, the reversible SOFC system has the potentials for low cost and high efficient hydrogen production through steam electrolysis. The cost for hydrogen production at large scale was estimated at ~$2.7/kg H2, comparing favorably with other electrolysis techology.« less

High Temperature Electrolysis using Electrode-Supported Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. E. O'Brien; C. M. Stoots

2010-07-01

An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. The cells currently under study were developed primarily for the fuel cell mode of operation. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (~10 µm thick), nickel-YSZ steam/hydrogen electrodes (~1400 µm thick), and manganite (LSM) air-side electrodes (~90 µm thick). The purpose of the present study was to document and compare the performance and degradation ratesmore » of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of DC potential sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-duration testing, first in the fuel cell mode, then in the electrolysis mode over more than 500 hours of operation. Results indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of the single-cell test apparatus developed specifically for these experiments.« less

Experimental design, operation, and results of a 4 kW high temperature steam electrolysis experiment

DOE PAGES

Zhang, Xiaoyu; O'Brien, James E.; Tao, Greg; ...

2015-08-06

High temperature steam electrolysis (HTSE) is a promising technology for large-scale hydrogen production. However, research on HTSE performance above the kW level is limited. This paper presents the results of 4 kW HTSE long-term test completed in a multi-kW test facility recently developed at the Idaho National Laboratory (INL). The 4 kW HTSE unit included two solid oxide electrolysis stacks operating in parallel, each of which included 40 electrode-supported planar cells. A current density of 0.41 A/cm2 was used for the long-term operation, resulting in a hydrogen production rate about 25 slpm. A demonstration of 920 hours stable operation wasmore » achieved. The paper also includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. As a result, this successful demonstration of multi-kW scale HTSE unit will help to advance the technology toward near-term commercialization.« less

The Concept and Experimental Investigation of CO2 and Steam Co-electrolysis for Resource Utilization in Space Exploration

NASA Technical Reports Server (NTRS)

Stoots, Carl; Mulloth, Lila M.; Luna, Bernadette; Varghese, Mini M.

2009-01-01

CO2 acquisition and utilization technologies will have a vital role in determining sustained and affordable life support and in-situ fuel production architectures for human and robotic exploration of Moon and Mars. For long-term human exploration to be practical, reliable technologies have to be implemented to capture and chemically reduce the metabolic CO2 from the cabin air to restitute oxygen consumption. Technologies that facilitate the in-situ capture and conversion of atmospheric CO2 to fuel are essential for a viable human mission to Mars and their demonstration on the moon is critical as well. This paper describes the concept and experimental investigation of a CO2 capture and reduction system that comprises an adsorption compressor and a CO2 and steam co-electrolysis unit. The process products include oxygen for life support and Syngas (CO and H2) for synthetic fuel production. Electrochemical performance in terms of CO2 conversion, oxygen production, and power consumption of a system with a capacity to process 1kg CO2 per day (1-person equivalent) will be discussed.

High-temperature electrolysis of synthetic seawater using solid oxide electrolyzer cells

NASA Astrophysics Data System (ADS)

Lim, Chee Kuan; Liu, Qinglin; Zhou, Juan; Sun, Qiang; Chan, Siew Hwa

2017-02-01

A Ni-YSZ/YSZ/LSCF-GDC solid oxide electrolyzer cell (SOEC) is used to investigate the effects of seawater electrolysis for hydrogen production through electrolyzing steam produced from simulated seawater bath. Steam electrolysis using an SOEC with its fuel electrode contaminated by sea salt is also investigated. Steam produced from seawater is found to be free of contaminants, which are present in the seawater. Similar electrochemical performance is observed from the polarization curves and impedance spectra when using steam produced from pure water and seawater. Their short-term degradation rates are similar, which are registered at 15% 1000 h-1 for both cases. For the case of direct sea salt contamination in an SOEC's fuel electrode, both the uncontaminated and contaminated cells exhibit rather similar performance as observed from the polarization curves and impedance spectra. The difference in ASR values from the polarization curves and impedance spectra between the uncontaminated and contaminated cell are all within a 10% range. Rather similar short-term degradation rates of 15% 1000 h-1 and 16% 1000 h-1 are recorded for the uncontaminated and contaminated cells, respectively. Post-mortem analysis shows that the sea salt impregnated into the cell has been vaporized at a typical SOEC operating temperature of 800 °C over the period of operation.

TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

DOE Office of Scientific and Technical Information (OSTI.GOV)

R. C. O'Brien; J. E. O'Brien; C. M. Stoots

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. Themore » test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.« less

Development of a Novel Efficient Solid-Oxide Hybrid for Co-generation of Hydrogen and Electricity Using Nearby Resources for Local Application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Greg, G.; Virkar, Anil, V.; Bandopadhyay, Sukumar

2009-06-30

Developing safe, reliable, cost-effective, and efficient hydrogen-electricity co-generation systems is an important step in the quest for national energy security and minimized reliance on foreign oil. This project aimed to, through materials research, develop a cost-effective advanced technology cogenerating hydrogen and electricity directly from distributed natural gas and/or coal-derived fuels. This advanced technology was built upon a novel hybrid module composed of solid-oxide fuel-assisted electrolysis cells (SOFECs) and solid-oxide fuel cells (SOFCs), both of which were in planar, anode-supported designs. A SOFEC is an electrochemical device, in which an oxidizable fuel and steam are fed to the anode and cathode,more » respectively. Steam on the cathode is split into oxygen ions that are transported through an oxygen ion-conducting electrolyte (i.e. YSZ) to oxidize the anode fuel. The dissociated hydrogen and residual steam are exhausted from the SOFEC cathode and then separated by condensation of the steam to produce pure hydrogen. The rationale was that in such an approach fuel provides a chemical potential replacing the external power conventionally used to drive electrolysis cells (i.e. solid oxide electrolysis cells). A SOFC is similar to the SOFEC by replacing cathode steam with air for power generation. To fulfill the cogeneration objective, a hybrid module comprising reversible SOFEC stacks and SOFC stacks was designed that planar SOFECs and SOFCs were manifolded in such a way that the anodes of both the SOFCs and the SOFECs were fed the same fuel, (i.e. natural gas or coal-derived fuel). Hydrogen was produced by SOFECs and electricity was generated by SOFCs within the same hybrid system. A stand-alone 5 kW system comprising three SOFEC-SOFC hybrid modules and three dedicated SOFC stacks, balance-of-plant components (including a tailgas-fired steam generator and tailgas-fired process heaters), and electronic controls was designed, though an overall integrated system assembly was not completed because of limited resources. An inexpensive metallic interconnects fabrication process was developed in-house. BOP components were fabricated and evaluated under the forecasted operating conditions. Proof-of-concept demonstration of cogenerating hydrogen and electricity was performed, and demonstrated SOFEC operational stability over 360 hours with no significant degradation. Cost analysis was performed for providing an economic assessment of the cost of hydrogen production using the targeted hybrid technology, and for guiding future research and development.« less

Natural gas-assisted steam electrolyzer

DOEpatents

Pham, Ai-Quoc; Wallman, P. Henrik; Glass, Robert S.

2000-01-01

An efficient method of producing hydrogen by high temperature steam electrolysis that will lower the electricity consumption to an estimated 65 percent lower than has been achievable with previous steam electrolyzer systems. This is accomplished with a natural gas-assisted steam electrolyzer, which significantly reduces the electricity consumption. Since this natural gas-assisted steam electrolyzer replaces one unit of electrical energy by one unit of energy content in natural gas at one-quarter the cost, the hydrogen production cost will be significantly reduced. Also, it is possible to vary the ratio between the electricity and the natural gas supplied to the system in response to fluctuations in relative prices for these two energy sources. In one approach an appropriate catalyst on the anode side of the electrolyzer will promote the partial oxidation of natural gas to CO and hydrogen, called Syn-Gas, and the CO can also be shifted to CO.sub.2 to give additional hydrogen. In another approach the natural gas is used in the anode side of the electrolyzer to burn out the oxygen resulting from electrolysis, thus reducing or eliminating the potential difference across the electrolyzer membrane.

Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides.

PubMed

Bi, Lei; Boulfrad, Samir; Traversa, Enrico

2014-12-21

Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions.

Co-electrolysis of steam and CO2 in full-ceramic symmetrical SOECs: a strategy for avoiding the use of hydrogen as a safe gas.

PubMed

Torrell, M; García-Rodríguez, S; Morata, A; Penelas, G; Tarancón, A

2015-01-01

The use of cermets as fuel electrodes for solid oxide electrolysis cells requires permanent circulation of reducing gas, e.g. H2 or CO, so called safe gas, in order to avoid oxidation of the metallic phase. Replacing metallic based electrodes by pure oxides is therefore proposed as an advantage for the industrial application of solid oxide electrolyzers. In this work, full-ceramic symmetrical solid oxide electrolysis cells have been investigated for steam/CO2 co-electrolysis. Electrolyte supported cells with La(0.75)Sr(0.25)Cr(0.5)Mn(0.5)O3-δ reversible electrodes have been fabricated and tested in co-electrolysis mode using different fuel compositions, from pure H2O to pure CO2, at temperatures between 850-900 °C. Electrochemical impedance spectroscopy and galvanostatic measurements have been carried out for the mechanistic understanding of the symmetrical cell performance. The content of H2 and CO in the product gas has been measured by in-line gas micro-chromatography. The effect of employing H2 as a safe gas has also been investigated. Maximum density currents of 750 mA cm(-2) and 620 mA cm(-2) have been applied at 1.7 V for pure H2O and for H2O : CO2 ratios of 1 : 1, respectively. Remarkable results were obtained for hydrogen-free fuel compositions, which confirmed the interest of using ceramic oxides as a fuel electrode candidate to reduce or completely avoid the use of safe gas in operation minimizing the contribution of the reverse water shift reaction (RWSR) in the process. H2 : CO ratios close to two were obtained for hydrogen-free tests fulfilling the basic requirements for synthetic fuel production. An important increase in the operation voltage was detected under continuous operation leading to a dramatic failure by delaminating of the oxygen electrode.

Comparative study of thermochemical processes for hydrogen production from biomass fuels.

PubMed

Biagini, Enrico; Masoni, Lorenzo; Tognotti, Leonardo

2010-08-01

Different thermochemical configurations (gasification, combustion, electrolysis and syngas separation) are studied for producing hydrogen from biomass fuels. The aim is to provide data for the production unit and the following optimization of the "hydrogen chain" (from energy source selection to hydrogen utilization) in the frame of the Italian project "Filiera Idrogeno". The project focuses on a regional scale (Tuscany, Italy), renewable energies and automotive hydrogen. Decentred and small production plants are required to solve the logistic problems of biomass supply and meet the limited hydrogen infrastructures. Different options (gasification with air, oxygen or steam/oxygen mixtures, combustion, electrolysis) and conditions (varying the ratios of biomass and gas input) are studied by developing process models with uniform hypothesis to compare the results. Results obtained in this work concern the operating parameters, process efficiencies, material and energetic needs and are fundamental to optimize the entire hydrogen chain. Copyright 2010 Elsevier Ltd. All rights reserved.

Methods and systems for producing syngas

DOEpatents

Hawkes, Grant L; O& #x27; Brien, James E; Stoots, Carl M; Herring, J. Stephen; McKellar, Michael G; Wood, Richard A; Carrington, Robert A; Boardman, Richard D

2013-02-05

Methods and systems are provided for producing syngas utilizing heat from thermochemical conversion of a carbonaceous fuel to support decomposition of at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells. Simultaneous decomposition of carbon dioxide and water or steam by one or more solid-oxide electrolysis cells may be employed to produce hydrogen and carbon monoxide. A portion of oxygen produced from at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells is fed at a controlled flow rate in a gasifier or combustor to oxidize the carbonaceous fuel to control the carbon dioxide to carbon monoxide ratio produced.

Engineering Design Elements of a Two-Phase Thermosyphon to Trannsfer NGNP Nuclear Thermal Energy to a Hydrogen Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piyush Sabharwal

2009-07-01

Two hydrogen production processes, both powered by a Next Generation Nuclear Plant (NGNP), are currently under investigation at Idaho National Laboratory. The first is high-temperature steam electrolysis, which uses both heat and electricity; the second is thermo-chemical production through the sulfur iodine process primarily using heat. Both processes require a high temperature (>850°C) for enhanced efficiency; temperatures indicative of the NGNP. Safety and licensing mandates prudently dictate that the NGNP and the hydrogen production facility be physically isolated, perhaps requiring separation of over 100 m.

The beneficial effects of straight open large pores in the support on steam electrolysis performance of electrode-supported solid oxide electrolysis cell

NASA Astrophysics Data System (ADS)

Lin, Jie; Chen, Long; Liu, Tong; Xia, Changrong; Chen, Chusheng; Zhan, Zhongliang

2018-01-01

This study is aimed at improving the electrochemical performance of electrode-supported solid oxide electrolysis cells (SOECs) by optimizing the pore structure of the supports. Two planar NiO-8 mol% yttria-stabilized zirconia supports are prepared, one by the phase-inversion tape casting, and the other by conventional tape casting method using graphite as the pore former. The former contains finger-like straight open large pores, while the latter contains randomly distributed and tortuous pores. The steam electrolysis of the cells with different microstructure cathode supports is measured. The cell supported on the cathode with straight pores shows a high current density of 1.42 A cm-2 and a H2 production rate of 9.89 mL (STP) cm-2 min-1 at 1.3 V and 50 vol % humidity and 750 °C, while the cell supported on the cathode with tortuous pores shows a current density of only 0.91 A cm-2 and a H2 production rate of 6.34 mL cm-2min-1. It is concluded that the introduction of large straight open pores into the cathode support allows fast gas phase transport and thus minimizes the concentration polarization. Furthermore, the straight pores could provide better access to the reaction site (the electrode functional layer), thereby reducing the activation polarization as well.

Systems Engineering Provides Successful High Temperature Steam Electrolysis Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charles V. Park; Emmanuel Ohene Opare, Jr.

2011-06-01

This paper describes two Systems Engineering Studies completed at the Idaho National Laboratory (INL) to support development of the High Temperature Stream Electrolysis (HTSE) process. HTSE produces hydrogen from water using nuclear power and was selected by the Department of Energy (DOE) for integration with the Next Generation Nuclear Plant (NGNP). The first study was a reliability, availability and maintainability (RAM) analysis to identify critical areas for technology development based on available information regarding expected component performance. An HTSE process baseline flowsheet at commercial scale was used as a basis. The NGNP project also established a process and capability tomore » perform future RAM analyses. The analysis identified which components had the greatest impact on HTSE process availability and indicated that the HTSE process could achieve over 90% availability. The second study developed a series of life-cycle cost estimates for the various scale-ups required to demonstrate the HTSE process. Both studies were useful in identifying near- and long-term efforts necessary for successful HTSE process deployment. The size of demonstrations to support scale-up was refined, which is essential to estimate near- and long-term cost and schedule. The life-cycle funding profile, with high-level allocations, was identified as the program transitions from experiment scale R&D to engineering scale demonstration.« less

Evaluation of Hybrid Power Plants using Biomass, Photovoltaics and Steam Electrolysis for Hydrogen and Power Generation

NASA Astrophysics Data System (ADS)

Petrakopoulou, F.; Sanz, J.

2014-12-01

Steam electrolysis is a promising process of large-scale centralized hydrogen production, while it is also considered an excellent option for the efficient use of renewable solar and geothermal energy resources. This work studies the operation of an intermediate temperature steam electrolyzer (ITSE) and its incorporation into hybrid power plants that include biomass combustion and photovoltaic panels (PV). The plants generate both electricity and hydrogen. The reference -biomass- power plant and four variations of a hybrid biomass-PV incorporating the reference biomass plant and the ITSE are simulated and evaluated using exergetic analysis. The variations of the hybrid power plants are associated with (1) the air recirculation from the electrolyzer to the biomass power plant, (2) the elimination of the sweep gas of the electrolyzer, (3) the replacement of two electric heaters with gas/gas heat exchangers, and (4) the replacement two heat exchangers of the reference electrolyzer unit with one heat exchanger that uses steam from the biomass power plant. In all cases, 60% of the electricity required in the electrolyzer is covered by the biomass plant and 40% by the photovoltaic panels. When comparing the hybrid plants with the reference biomass power plant that has identical operation and structure as that incorporated in the hybrid plants, we observe an efficiency decrease that varies depending on the scenario. The efficiency decrease stems mainly from the low effectiveness of the photovoltaic panels (14.4%). When comparing the hybrid scenarios, we see that the elimination of the sweep gas decreases the power consumption due to the elimination of the compressor used to cover the pressure losses of the filter, the heat exchangers and the electrolyzer. Nevertheless, if the sweep gas is used to preheat the air entering the boiler of the biomass power plant, the efficiency of the plant increases. When replacing the electric heaters with gas-gas heat exchangers, the efficiency of the plant increases, although the higher pressure losses of the flue-gas path increase the requirements of the air compressor. Finally, replacing the two heat exchangers of the electrolyzer unit with one that uses extracted steam from the biomass power plant can lead to an overall decrease in the operating and investment costs of the plant.

Bias polarization study of steam electrolysis by composite oxygen electrode Ba0.5Sr0.5Co0.8Fe0.2O3-δ/BaCe0.4Zr0.4Y0.2O3-δ

NASA Astrophysics Data System (ADS)

Yang, Tao; Shaula, Aliaksandr; Pukazhselvan, D.; Ramasamy, Devaraj; Deng, Jiguang; da Silva, E. L.; Duarte, Ricardo; Saraiva, Jorge A.

2017-12-01

The polarization behavior of Ba0.5Sr0.5Co0.8Fe0.2O3-δ-BaCe0.4Zr0.4Y0.2O3-δ (BSCF-BCZY) electrode under steam electrolysis conditions was studied in detail. The composite oxygen electrode supported by BCZY electrolyzer has been assessed as a function of temperature (T), water vapor partial pressures (pH2O), and bias polarization voltage for electrodes of comparable microstructure. The Electrochemical impedance spectra show two depressed arcs in general without bias polarization. And the electrode resistance became smaller with the increase of the bias polarization under the same water vapor partial pressures. The total resistance of the electrode was shown to be significantly affected by temperature, with the same level of pH2O and bias polarization voltage. This result highlights BSCF-BCZY as an effective oxygen electrode under moderate polarization and pH2O conditions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, C.E.; Kuhn, I.F. Jr.

The fuel cell electric vehicle (FCEV) is undoubtedly the only option that can meet both the California zero emission vehicle (ZEV) standard and the President`s goal of tripling automobile efficiency without sacrificing performance in a standard 5-passenger vehicle. The three major automobile companies are designing and developing FCEVs powered directly by hydrogen under cost-shared contracts with the Department of Energy. Once developed, these vehicles will need a reliable and inexpensive source of hydrogen. Steam reforming of natural gas would produce the least expensive hydrogen, but funding may not be sufficient initially to build both large steam reforming plants and themore » transportation infrastructure necessary to deliver that hydrogen to geographically scattered FCEV fleets or individual drivers. This analysis evaluates the economic feasibility of using small scale water electrolysis to provide widely dispersed but cost-effective hydrogen for early FCEV demonstrations. We estimate the cost of manufacturing a complete electrolysis system in large quantities, including compression and storage, and show that electrolytic hydrogen could be cost competitive with fully taxed gasoline, using existing residential off-peak electricity rates.« less

A comparison between fuel cells and other alternatives for marine electric power generation

NASA Astrophysics Data System (ADS)

Welaya, Yousri M. A.; El Gohary, M. Morsy; Ammar, Nader R.

2011-06-01

The world is facing a challenge in meeting its needs for energy. Global energy consumption in the last halfcentury has increased very rapidly and is expected to continue to grow over the next 50 years. However, it is expected to see significant differences between the last 50 years and the next. This paper aims at introducing a good solution to replace or work with conventional marine power plants. This includes the use of fuel cell power plant operated with hydrogen produced through water electrolysis or hydrogen produced from natural gas, gasoline, or diesel fuels through steam reforming processes to mitigate air pollution from ships.

RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: STACK TESTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

X, Zhang; J. E. O'Brien; R. C. O'Brien

2012-07-01

High temperature steam electrolysis is a promising technology for efficient sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolytesupportedmore » and electrode-supported SOEC stacks were provided by Ceramatec Inc., Materials and Systems Research Inc. (MSRI), and Saint Gobain Advanced Materials (St. Gobain), respectively for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technology developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, respectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. A three-cell short stack provided by St. Gobain, however, showed rapid degradation in the electrolysis mode. Improvements on electrode materials, interconnect coatings, and electrolyteelectrode interface microstructures contribute to better durability of SOEC stacks.« less

Perovskite Sr2Fe1.5Mo0.5O6-δ as electrode materials for symmetrical solid oxide electrolysis cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Qiang; Yang, Chenghao; Dong, Xihui

2010-10-01

Perovskite Sr2Fe1.5Mo0.5O6-δ (SFM) has been successfully prepared by a microwave-assisted combustion method in air and employed as both anode and cathode in symmetrical solid oxide electrolysis cells (SOECs) for hydrogen production for the first time in this work. Influence of cell operating temperature, absolute humidity (AH) as well as applied direct current (DC) on the impedance of single cells with the configuration of SFM|La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM)|SFM has been evaluated. Under open circuit conditions and 60 vol.% AH, the cell polarization resistance, RP is as low as 0.26 Ω cm2 at 900 °C. An electrolysis current of 0.88 A cm-2 and amore » hydrogen production rate as high as 380 mL cm-2 h have been achieved at 900 °C with an electrolysis voltage of 1.3 V and 60 vol.% AH. Further, the cell has demonstrated good stability in the long-term steam electrolysis test. The results showed that the cell electrolysis performance was even better than that of the reported strontium doped lanthanum manganite (LSM) – yttria stabilized zirconia (YSZ)|YSZ|Ni–YSZ cell, indicating that SFM could be a very promising electrode material for the practical application of SOEC technology.« less

Cleaning the air and improving health with hydrogen fuel-cell vehicles.

PubMed

Jacobson, M Z; Colella, W G; Golden, D M

2005-06-24

Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

Cleaning the Air and Improving Health with Hydrogen Fuel-Cell Vehicles

NASA Astrophysics Data System (ADS)

Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

2005-06-01

Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

Status on the Component Models Developed in the Modelica Framework: High-Temperature Steam Electrolysis Plant & Gas Turbine Power Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suk Kim, Jong; McKellar, Michael; Bragg-Sitton, Shannon M.

This report has been prepared as part of an effort to design and build a modeling and simulation (M&S) framework to assess the economic viability of a nuclear-renewable hybrid energy system (N-R HES). In order to facilitate dynamic M&S of such an integrated system, research groups in multiple national laboratories have been developing various subsystems as dynamic physics-based components using the Modelica programming language. In fiscal year (FY) 2015, Idaho National Laboratory (INL) performed a dynamic analysis of two region-specific N-R HES configurations, including the gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) and brackish water reverse osmosis desalination plants asmore » industrial processes. In FY 2016, INL has developed two additional subsystems in the Modelica framework: a high-temperature steam electrolysis (HTSE) plant and a gas turbine power plant (GTPP). HTSE has been proposed as a high priority industrial process to be integrated with a light water reactor (LWR) in an N-R HES. This integrated energy system would be capable of dynamically apportioning thermal and electrical energy (1) to provide responsive generation to the power grid and (2) to produce alternative industrial products (i.e., hydrogen and oxygen) without generating any greenhouse gases. A dynamic performance analysis of the LWR/HTSE integration case was carried out to evaluate the technical feasibility (load-following capability) and safety of such a system operating under highly variable conditions requiring flexible output. To support the dynamic analysis, the detailed dynamic model and control design of the HTSE process, which employs solid oxide electrolysis cells, have been developed to predict the process behavior over a large range of operating conditions. As first-generation N-R HES technology will be based on LWRs, which provide thermal energy at a relatively low temperature, complementary temperature-boosting technology was suggested for integration with the HTSE process that requires higher temperature input. Simulation results involving several case studies show that the suggested control scheme could maintain the controlled variables (including the steam utilization factor, cathode stream inlet composition, and temperatures of the process streams at various locations) within desired limits under various plant operating conditions. The results also indicate that the proposed HTSE plant could provide operational flexibility to participate in energy management at the utility scale by dynamically optimizing the use of excess plant capacity within an N-R HES. A natural-gas fired GTPP has been proposed as a secondary energy supply to be included in an N-R HES. This auxiliary generator could be used to cover rapid dynamics in grid demand that cannot be met by the remainder of the N-R HES. To evaluate the operability and controllability of the proposed process during transients between load (demand) levels, the dynamic model and control design were developed. Special attention was given to the design of feedback controllers to regulate the power frequency, and exhaust gas and turbine firing temperatures. Several case studies were performed to investigate the system responses to the major disturbance (power load demand) in such a control system. The simulation results show that the performance of the proposed control strategies was satisfactory under each test when the GTPP experienced high rapid variations in the load.« less

Improved Durability of SOEC Stacks for High Temperature Electrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

James E. O'Brien; Robert C. O'Brien; Xiaoyu Zhang

2013-01-01

High temperature steam electrolysis is a promising technology for efficient and sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology can be realized. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-termmore » durability of SOECs. Electrolyte-supported and electrode-supported SOEC stacks were provided by Ceramatec Inc. and Materials and Systems Research Inc. (MSRI), respectively, for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technologies developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, espectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. Optimization of electrode materials, interconnect coatings, and electrolyte-electrode interface microstructures contribute to better durability of SOEC stacks.« less

Power-to-Syngas: An Enabling Technology for the Transition of the Energy System?

PubMed

Foit, Severin R; Vinke, Izaak C; de Haart, Lambertus G J; Eichel, Rüdiger-A

2017-05-08

Power-to-X concepts promise a reduction of greenhouse gas emissions simultaneously guaranteeing a safe energy supply even at high share of renewable power generation, thus becoming a cornerstone of a sustainable energy system. Power-to-syngas, that is, the electrochemical conversion of steam and carbon dioxide with the use of renewably generated electricity to syngas for the production of synfuels and high-value chemicals, offers an efficient technology to couple different energy-intense sectors, such as "traffic and transportation" and "chemical industry". Syngas produced by co-electrolysis can thus be regarded as a key-enabling step for a transition of the energy system, which offers additionally features of CO 2 -valorization and closed carbon cycles. Here, we discuss advantages and current limitations of low- and high-temperature co-electrolysis. Advances in both fundamental understanding of the basic reaction schemes and stable high-performance materials are essential to further promote co-electrolysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

System for the co-production of electricity and hydrogen

DOEpatents

Pham, Ai Quoc; Anderson, Brian Lee

2007-10-02

Described herein is a system for the co-generation of hydrogen gas and electricity, wherein the proportion of hydrogen to electricity can be adjusted from 0% to 100%. The system integrates fuel cell technology for power generation with fuel-assisted steam-electrolysis. A hydrocarbon fuel, a reformed hydrocarbon fuel, or a partially reformed hydrocarbon fuel can be fed into the system.

Status Report on the High-Temperature Steam Electrolysis Plant Model Developed in the Modelica Framework (FY17)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jong Suk; Bragg-Sitton, Shannon M.; Boardman, Richard D.

This report has been prepared as part of an effort to design and build a modeling and simulation (M&S) framework to assess the economic viability of a nuclear-renewable hybrid energy system (N-R HES). In order to facilitate dynamic M&S of such an integrated system, research groups in multiple national laboratories have been developing various subsystems as dynamic physics-based components using the Modelica programming language. In fiscal year 2015 (FY15), Idaho National Laboratory (INL) performed a dynamic analysis of two region-specific N-R HES configurations, including the gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) and brackish water reverse osmosis desalination plants asmore » industrial processes. In FY16, INL developed two additional subsystems in the Modelica framework: (1) a high-temperature steam electrolysis (HTSE) plant as a high priority industrial plant to be integrated with a light water reactor (LWR) within an N-R HES and (2) a gas turbine power plant as a secondary energy supply. In FY17, five new components (i.e., a feedwater pump, a multi-stage compression system, a sweep-gas turbine, flow control valves, and pressure control valves) have been incorporated into the HTSE system proposed in FY16, aiming to better realistically characterize all key components of concern. Special attention has been given to the controller settings based on process models (i.e., direct synthesis method), aiming to improve process dynamics and controllability. A dynamic performance analysis of the improved LWR/HTSE integration case was carried out to evaluate the technical feasibility (load-following capability) and safety of such a system operating under highly variable conditions requiring flexible output. The analysis (evaluated in terms of the step response) clearly shows that the FY17 model resulted in superior output responses with much smaller settling times and less oscillatory behavior in response to disturbances in the electric load than those observed with the FY16 model. Simulation results involving several case studies show that the suggested control scheme could maintain the controlled variables (including the steam utilization factor, cathode stream inlet composition, and temperatures and pressures of the process streams at various locations) within desired limits under various plant operating conditions. The results also indicate that the proposed HTSE plant could provide operational flexibility to participate in energy management at the utility scale by dynamically optimizing the use of excess plant capacity within an N-R HES.« less

Electrochemical Upgrading of Bio-Oil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elangovan, S.; Larsen, Dennis; Bay, Insoo

Bio-oil produced by fast pyrolysis of biomass is a potential source of low carbon, renewable hydrocarbon fuel. However, the properties such as low heating value, incomplete volatility, acidity, instability, and incompatibility with standard fuels restrict its use. The undesirable properties of pyrolysis oil result from its chemical composition that mostly consists of different classes of oxygenated organic compounds. Current process of Hydrodeoxygenation to remove oxygen involves high-temperature, high-pressure processing in the presence of hydrogen and catalyst. An alternative process of deoxygenation of bio-oil using solid-state, oxygen conductor based electrochemical cell is under investigation. The electrolysis process removes oxygen from themore » oxygenated organic molecule as well from steam to produce hydrogen in-situ allowing for a distributed, small scale integrated upgrading unit. Mixtures of model compounds and a slip stream of pyrolysis vapor were tested. The results show the potential for integrating a pyrolyzer and an electrochemical device for stabilizing pyrolysis oil.« less

An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry

2014-03-01

Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feedmore » a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.« less

Treatment of high salt oxidized modified starch waste water using micro-electrolysis, two-phase anaerobic aerobic and electrolysis for reuse

NASA Astrophysics Data System (ADS)

Yi, Xuenong; Wang, Yulin

2017-06-01

A combined process of micro-electrolysis, two-phase anaerobic, aerobic and electrolysis was investigated for the treatment of oxidized modified starch wastewater (OMSW). Optimum ranges for important operating variables were experimentally determined and the treated water was tested for reuse in the production process of corn starch. The optimum hydraulic retention time (HRT) of micro-electrolysis, methanation reactor, aerobic process and electrolysis process were 5, 24, 12 and 3 h, respectively. The addition of iron-carbon fillers to the acidification reactor was 200 mg/L while the best current density of electrolysis was 300 A/m2. The biodegradability was improved from 0.12 to 0.34 by micro-electrolysis. The whole treatment was found to be effective with removal of 96 % of the chemical oxygen demand (COD), 0.71 L/day of methane energy recovery. In addition, active chlorine production (15,720 mg/L) was obtained by electrolysis. The advantage of this hybrid process is that, through appropriate control of reaction conditions, effect from high concentration of salt on the treatment was avoided. Moreover, the process also produced the material needed in the production of oxidized starch while remaining emission-free and solved the problem of high process cost.

HYFIRE II: fusion/high-temperature electrolysis conceptual-design study. Annual report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fillo, J.A.

1983-08-01

As in the previous HYFIRE design study, the current study focuses on coupling a Tokamak fusion reactor with a high-temperature blanket to a High-Temperature Electrolyzer (HTE) process to produce hydrogen and oxygen. Scaling of the STARFIRE reactor to allow a blanket power to 6000 MW(th) is also assumed. The primary difference between the two studies is the maximum inlet steam temperature to the electrolyzer. This temperature is decreased from approx. 1300/sup 0/ to approx. 1150/sup 0/C, which is closer to the maximum projected temperature of the Westinghouse fuel cell design. The process flow conditions change but the basic design philosophymore » and approaches to process design remain the same as before. Westinghouse assisted in the study in the areas of systems design integration, plasma engineering, balance-of-plant design, and electrolyzer technology.« less

Japan's Sunshine Project

NASA Astrophysics Data System (ADS)

1992-07-01

A summary report is given on the results of hydrogen energy research and development achieved during 1991 under the Sunshine Project. In hydrogen manufacturing, regenerative cells that can also generate power as fuel cells were discussed by using solid macromolecular electrolytic films for the case where no electrolysis is carried out with water electrolysis. Yttria stabilized zirconia (YSZ), an oxide solid electrolyte was used for the basic research on high-temperature steam electrolysis. Compositions of hydrogen storage alloys and their deterioration mechanisms were investigated to develop hydrogen transportation and storage technologies. High-density hydrides were searched, and fluidization due to paraffin was discussed. Electrode materials and forming technologies were discussed to develop a hydrogen to power conversion system using hydrogen storage alloys as reversible electrodes. Hydrogen-oxygen combustion was studied in terms of reactive theories, and so was the control of ignition and combustion using ultraviolet ray ignition plasma. Studies were made on hydrogen brittlement in welds on materials in hydrogen utilization and its preventive measures. Surveys were given on technical movements and development problems in high-efficiency, pollution-free hydrogen combustion turbines.

Renewable hydrogen production via thermochemical/electrochemical coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ambrosini, Andrea; Babiniec, Sean Michael; Miller, James E.

A coupled electrochemical/thermochemical cycle was investigated to produce hydrogen from renewable resources. Like a conventional thermochemical cycle, this cycle leverages chemical energy stored in a thermochemical working material that is reduced thermally by solar energy. However, in this concept, the stored chemical energy only needs to be partially, but not fully, capable of splitting steam to produce hydrogen. To complete the process, a proton-conducting membrane is driven to separate hydrogen as it is produced, thus shifting the thermodynamics toward further hydrogen production. This novel coupled-cycle concept provides several benefits. First, the required oxidation enthalpy of the reversible thermochemical material ismore » reduced, enabling the process to occur at lower temperatures. Second, removing the requirement for spontaneous steam-splitting widens the scope of materials compositions, allowing for less expensive/more abundant elements to be used. Lastly, thermodynamics calculations suggest that this concept can potentially reach higher efficiencies than photovoltaic-to-electrolysis hydrogen production methods. This Exploratory Express LDRD involved assessing the practical feasibility of the proposed coupled cycle. A test stand was designed and constructed and proton-conducting membranes were synthesized. While the full proof of concept was not achieved, the individual components of the experiment were validated and new capabilities that can be leveraged by a variety of programs were developed.« less

Improved cell for water-vapor electrolysis

NASA Technical Reports Server (NTRS)

Aylward, J. R.

1981-01-01

Continuous-flow electrolytic cells decompose water vapor in steam and room air into hydrogen and oxygen. Sintered iridium oxide catalytic anode coating yields dissociation rates hundredfold greater than those obtained using platinum black. Cell consists of two mirror-image cells, with dual cathode sandwiched between two anodes. Gas traverses serpentine channels within cell and is dissociated at anode. Oxygen mingles with gas stream, while hydrogen migrates through porous matrix and is liberated as gas at cathode.

Inactivation characteristics of ozone and electrolysis process for ballast water treatment using B. subtilis spores as a probe.

PubMed

Jung, Youmi; Yoon, Yeojoon; Hong, Eunkyung; Kwon, Minhwan; Kang, Joon-Wun

2013-07-15

Since ballast water affects the ocean ecosystem, the International Maritime Organization (IMO) sets a standard for ballast water management and might impose much tighter regulations in the future. The aim of this study is to evaluate the inactivation efficiency of ozonation, electrolysis, and an ozonation-electrolysis combined process, using B. subtilis spores. In seawater ozonation, HOBr is the key active substance for inactivation, because of rapid reactivity of ozone with Br(-) in seawater. In seawater electrolysis, it is also HOBr, but not HOCl, because of the rapid reaction of HOCl with Br(-), which has not been recognized carefully, even though many electrolysis technologies have been approved by the IMO. Inactivation pattern was different in ozonation and electrolysis, which has some limitations with the tailing or lag-phase, respectively. However, each deficiency can be overcome with a combined process, which is most effective as a sequential application of ozonation followed by electrolysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Investigation of the synergistic effects for p-nitrophenol mineralization by a combined process of ozonation and electrolysis using a boron-doped diamond anode.

PubMed

Qiu, Cuicui; Yuan, Shi; Li, Xiang; Wang, Huijiao; Bakheet, Belal; Komarneni, Sridhar; Wang, Yujue

2014-09-15

Electrolysis and ozonation are two commonly used technologies for treating wastewaters contaminated with nitrophenol pollutants. However, they are often handicapped by their slow kinetics and low yields of total organic carbon (TOC) mineralization. To improve TOC mineralization efficiency, we combined electrolysis using a boron-doped diamond (BDD) anode with ozonation (electrolysis-O3) to treat a p-nitrophenol (PNP) aqueous solution. Up to 91% TOC was removed after 60 min of the electrolysis-O3 process. In comparison, only 20 and 44% TOC was respectively removed by individual electrolysis and ozonation treatment conducted under similar reaction conditions. The result indicates that when electrolysis and ozonation are applied simultaneously, they have a significant synergy for PNP mineralization. This synergy can be mainly attributed to (i) the rapid degradation of PNP to carboxylic acids (e.g., oxalic acid and acetic acid) by O3, which would otherwise take a much longer time by electrolysis alone, and (ii) the effective mineralization of the ozone-refractory carboxylic acids to CO2 by OH generated from multiple sources in the electrolysis-O3 system. The result suggests that combining electrolysis with ozonation can provide a simple and effective way to mutually compensate the limitations of the two processes for degradation of phenolic pollutants. Copyright © 2014 Elsevier B.V. All rights reserved.

Summary Report on Solid-oxide Electrolysis Cell Testing and Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.E. O'Brien; X. Zhang; R.C. O'Brien

2012-01-01

Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells (SOECs) for large-scale hydrogen production from steam over a temperature range of 800 to 900 C. From 2003 to 2009, this work was sponsored by the United States Department of Energy Nuclear Hydrogen Initiative, under the Office of Nuclear Energy. Starting in 2010, the high-temperature electrolysis (HTE) research program has been sponsored by the INL Next Generation Nuclear Plant Project. This report provides a summaryof program activities performed in Fiscal Year (FY) 2011 and the first quarter of FY-12, with a focus on small-scale testing and cellmore » development activities. HTE research priorities during this period have included the development and testing of SOEC and stack designs that exhibit high-efficiency initial performance and low, long-term degradation rates. This report includes contributions from INL and five industry partners: Materials and Systems Research, Incorporated (MSRI); Versa Power Systems, Incorporated (VPS); Ceramatec, Incorporated; National Aeronautics and Space Administration - Glenn Research Center (NASA - GRC); and the St. Gobain Advanced Materials Division. These industry partners have developed SOEC cells and stacks for in-house testing in the electrolysis mode and independent testing at INL. Additional fundamental research and post-test physical examinations have been performed at two university partners: Massachusetts Institute of Technology (MIT) and the University of Connecticut. Summaries of these activities and test results are also presented in this report.« less

LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. E. O'Brien; R. C. O'Brien; X. Zhang

2011-11-01

Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cellmore » and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.« less

Design of optimum solid oxide membrane electrolysis cells for metals production

DOE PAGES

Guan, Xiaofei; Pal, Uday B.

2015-12-24

Oxide to metal conversion is one of the most energy-intensive steps in the value chain for metals production. Solid oxide membrane (SOM) electrolysis process provides a general route for directly reducing various metal oxides to their respective metals, alloys, or intermetallics. Because of its lower energy use and ability to use inert anode resulting in zero carbon emission, SOM electrolysis process emerges as a promising technology that can replace the state-of-the-art metals production processes. In this paper, a careful study of the SOM electrolysis process using equivalent DC circuit modeling is performed and correlated to the experimental results. Finally, amore » discussion on relative importance of each resistive element in the circuit and on possible ways of lowering the rate-limiting resistive elements provides a generic guideline for designing optimum SOM electrolysis cells.« less

Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation.

PubMed

Zhang, Zhenchao

2017-12-01

In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H 2 O 2 dosage of 12 mg/L, with a H 2 O 2 /Fe 2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China (GB8978-1996).

Electrolysis Performance Improvement Concept Study (EPICS) flight experiment phase C/D

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Lee, M. G.

1995-01-01

The overall purpose of the Electrolysis Performance Improvement Concept Study flight experiment is to demonstrate and validate in a microgravity environment the Static Feed Electrolyzer concept as well as investigate the effect of microgravity on water electrolysis performance. The scope of the experiment includes variations in microstructural characteristics of electrodes and current densities in a static feed electrolysis cell configuration. The results of the flight experiment will be used to improve efficiency of the static feed electrolysis process and other electrochemical regenerative life support processes by reducing power and expanding the operational range. Specific technologies that will benefit include water electrolysis for propulsion, energy storage, life support, extravehicular activity, in-space manufacturing and in-space science in addition to other electrochemical regenerative life support technologies such as electrochemical carbon dioxide and oxygen separation, electrochemical oxygen compression and water vapor electrolysis. The Electrolysis Performance Improvement Concept Study flight experiment design incorporates two primary hardware assemblies: the Mechanical/Electrochemical Assembly and the Control/Monitor Instrumentation. The Mechanical/Electrochemical Assembly contains three separate integrated electrolysis cells along with supporting pressure and temperature control components. The Control/Monitor Instrumentation controls the operation of the experiment via the Mechanical/Electrochemical Assembly components and provides for monitoring and control of critical parameters and storage of experimental data.

Achieving High Efficiency and Eliminating Degradation in Solid Oxide Electrochemical Cells Using High Oxygen-Capacity Perovskite.

PubMed

Jun, Areum; Kim, Junyoung; Shin, Jeeyoung; Kim, Guntae

2016-09-26

Recently, there have been efforts to use clean and renewable energy because of finite fossil fuels and environmental problems. Owing to the site-specific and weather-dependent characteristics of the renewable energy supply, solid oxide electrolysis cells (SOECs) have received considerable attention to store energy as hydrogen. Conventional SOECs use Ni-YSZ (yttria-stabilized zirconia) and LSM (strontium-doped lanthanum manganites)-YSZ as electrodes. These electrodes, however, suffer from redox-instability and coarsening of the Ni electrode along with delamination of the LSM electrode during steam electrolysis. In this study, we successfully design and fabricate highly efficient SOECs using layered perovskites, PrBaMn2 O5+δ (PBM) and PrBa0.5 Sr0.5 Co1.5 Fe0.5 O5+δ (PBSCF50), as both electrodes for the first time. The SOEC with layered perovskites as both-side electrodes shows outstanding performance, reversible cycling, and remarkable stability over 600 hours. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Coupled electro-thermal field in a high current electrolysis cell or liquid metal batteries

PubMed Central

Cai, Liwei; Ni, Haiou; Lu, Gui-Min; Yu, Jian-Guo

2018-01-01

Coupled electro-thermal field exists widely in chemical batteries and electrolysis industry. In this study, a three-dimensional numerical model, which is based on the finite-element software ANSYS, has been built to simulate the electro-thermal field in a magnesium electrolysis cell. The adjustment of the relative position of the anode and cathode can change the energy consumption of the magnesium electrolysis process significantly. Besides, the current intensity has a nonlinear effect on heat balance, and the effects of heat transfer coefficients, electrolysis and air temperature on the heat balance have been released to maintain the thermal stability in a magnesium electrolysis cell. The relationship between structure as well as process parameters and electro-thermal field has been obtained and the simulation results can provide experience for the scale-up design in liquid metal batteries. PMID:29515848

NEW MATERIAL NEEDS FOR HYDROCARBON FUEL PROCESSING: Generating Hydrogen for the PEM Fuel Cell

NASA Astrophysics Data System (ADS)

Farrauto, R.; Hwang, S.; Shore, L.; Ruettinger, W.; Lampert, J.; Giroux, T.; Liu, Y.; Ilinich, O.

2003-08-01

The hydrogen economy is fast approaching as petroleum reserves are rapidly consumed. The fuel cell promises to deliver clean and efficient power by combining hydrogen and oxygen in a simple electrochemical device that directly converts chemical energy to electrical energy. Hydrogen, the most plentiful element available, can be extracted from water by electrolysis. One can imagine capturing energy from the sun and wind and/or from the depths of the earth to provide the necessary power for electrolysis. Alternative energy sources such as these are the promise for the future, but for now they are not feasible for power needs across the globe. A transitional solution is required to convert certain hydrocarbon fuels to hydrogen. These fuels must be available through existing infrastructures such as the natural gas pipeline. The present review discusses the catalyst and adsorbent technologies under development for the extraction of hydrogen from natural gas to meet the requirements for the proton exchange membrane (PEM) fuel cell. The primary market is for residential applications, where pipeline natural gas will be the source of H2 used to power the home. Other applications including the reforming of methanol for portable power applications such as laptop computers, cellular phones, and personnel digital equipment are also discussed. Processing natural gas containing sulfur requires many materials, for example, adsorbents for desulfurization, and heterogeneous catalysts for reforming (either autothermal or steam reforming) water gas shift, preferential oxidation of CO, and anode tail gas combustion. All these technologies are discussed for natural gas and to a limited extent for reforming methanol.

Microbial bioelectrosynthesis of hydrogen: Current challenges and scale-up.

PubMed

Kitching, Michael; Butler, Robin; Marsili, Enrico

2017-01-01

Sustainable energy supplies are needed to supplement and eventually replace fossil fuels. Molecular hydrogen H 2 is a clean burning, high-energy fuel that is also used as reducing gas in industrial processes. H 2 is mainly synthesized by steam reforming of natural gas, a non-renewable fuel. There are biosynthetic strategies for H 2 production; however, they are associated with poor yield and have high cost. The application of an electrochemical driving force in a microbial electrolysis cell (MEC) improves the yield of biological reactions. The performance of the MEC is influenced by experimental parameters such as the electrode material, reactor design, microbial consortia and the substrate. In this review, factors that affect the performance of MECs are discussed and critically analysed. The potential for scale-up of H 2 bioelectrosynthesis is also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Energy-Efficient and Environmentally Friendly Solid Oxide Membrane Electrolysis Process for Magnesium Oxide Reduction: Experiment and Modeling

NASA Astrophysics Data System (ADS)

Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

2014-06-01

This paper reports a solid oxide membrane (SOM) electrolysis experiment using an LSM(La0.8Sr0.2MnO3-δ)-Inconel inert anode current collector for production of magnesium and oxygen directly from magnesium oxide at 1423 K (1150 °C). The electrochemical performance of the SOM cell was evaluated by means of various electrochemical techniques including electrochemical impedance spectroscopy, potentiodynamic scan, and electrolysis. Electronic transference numbers of the flux were measured to assess the magnesium dissolution in the flux during SOM electrolysis. The effects of magnesium solubility in the flux on the current efficiency and the SOM stability during electrolysis are discussed. An inverse correlation between the electronic transference number of the flux and the current efficiency of the SOM electrolysis was observed. Based on the experimental results, a new equivalent circuit of the SOM electrolysis process is presented. A general electrochemical polarization model of SOM process for magnesium and oxygen gas production is developed, and the maximum allowable applied potential to avoid zirconia dissociation is calculated as well. The modeling results suggest that a high electronic resistance of the flux and a relatively low electronic resistance of SOM are required to achieve membrane stability, high current efficiency, and high production rates of magnesium and oxygen.

An Environmentally Friendly Process Involving Refining and Membrane-Based Electrolysis for Magnesium Recovery from Partially Oxidized Scrap Alloy

NASA Astrophysics Data System (ADS)

Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

2013-10-01

Magnesium is recovered from partially oxidized scrap alloy by combining refining and solid oxide membrane (SOM) electrolysis. In this combined process, a molten salt eutectic flux (45 wt.% MgF2-55 wt.% CaF2) containing 10 wt.% MgO and 2 wt.% YF3 was used as the medium for magnesium recovery. During refining, magnesium and its oxide are dissolved from the scrap into the molten flux. Forming gas is bubbled through the flux and the dissolved magnesium is removed via the gas phase and condensed in a separate condenser at a lower temperature. The molten flux has a finite solubility for magnesium and acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium recovered has high purity. After refining, SOM electrolysis is performed in the same reactor to enable electrolysis of the dissolved magnesium oxide in the molten flux producing magnesium at the cathode and oxygen at the SOM anode. During SOM electrolysis, it is necessary to decrease the concentration of the dissolved magnesium in the flux to improve the faradaic current efficiency and prevent degradation of the SOM. Thus, for both refining and SOM electrolysis, it is very important to measure and control the magnesium solubility in the molten flux. High magnesium solubility facilitates refining whereas lower solubility benefits the SOM electrolysis process. Computational fluid dynamics modeling was employed to simulate the flow behavior of the flux stirred by the forming gas. Based on the modeling results, an optimized design of the stirring tubes and its placement in the flux are determined for efficiently removing the dissolved magnesium and also increasing the efficiency of the SOM electrolysis process.

Al/sub 2/S/sub 3/ preparation and use in electrolysis process for aluminum production

DOEpatents

Hsu, C.C.; Loutfy, R.O.; Yao, N.P.

A continuous process for producing aluminum sulfide and for electrolyzing the aluminum sulfide to form metallic aluminum in which the aluminum sulfide is produced from aluminum oxide and COS or CS/sub 2/ in the presence of a chloride melt which also serves as the electrolysis bath. Circulation between the reactor and electrolysis cell is carried out to maintain the desired concentration of aluminum sulfide in the bath.

Advancements in oxygen generation and humidity control by water vapor electrolysis

NASA Technical Reports Server (NTRS)

Heppner, D. B.; Sudar, M.; Lee, M. C.

1988-01-01

Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

Technology advancement of the static feed water electrolysis process

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Wynveen, R. A.

1977-01-01

A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

Sustainability development platform for nuclear–renewable energy integration: Environmental impacts, economics, and socio-political implications

DOE PAGES

Bolden, Lauren; Sabharwall, Piyush; Bragg-Sitton, Shannon; ...

2015-01-01

Global energy needs are primarily being met with fossil fuel plants in both developed and developing nations. Although it is unlikely to entirely replace fossil fuel systems, the incorporation of alternative energy systems that produce fewer emissions and utilize fewer resources may prove useful in furthering sustainable energy practices. Nuclear and Renewable Energy Integration (NREI) represents one potential, alternative system and is comprised of both nuclear and renewable technologies coupled with energy storage and industrial process heat applications. This article reviews the fundamentals of sustainability and its drivers, defines the necessary scope for analyzing energy systems, details widely used sustainabilitymore » metrics, and assesses sustainability through the sustainability efficiency factor (SEF) based on the core pillars of economy, environment, and society—all of which aim to promote future sustainable development. The assessment is performed for an NREI system comprised of a small modular reactor (SMR), where a portion of the heat generated is utilized for hydrogen production through high-temperature steam electrolysis (HTSE). The global warming potential for NREI is compared to the typical emissions observed for hydrogen production via steam methane reforming and are estimated to yield 92.6% fewer grams of CO 2-equivalent per kilogram of hydrogen produced. Furthermore, the calculated SEF for NREI is 22.2% higher than steam methane reforming. Because SMR designs are at varying design, developmental, and deployment stages, a method of estimating economics is presented to demonstrate the differences observed between first-of-a-kind (FOAK) and nth-of-a-kind (NOAK) units, as well as the resulting total capital investment cost. Lastly, a comprehensive list of considerations necessary for future energy system development was enumerated based on four core assessment areas: technical feasibility, environmental impact, economic feasibility and impact, and socio-political impacts.« less

Sustainability development platform for nuclear–renewable energy integration: Environmental impacts, economics, and socio-political implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolden, Lauren; Sabharwall, Piyush; Bragg-Sitton, Shannon

Global energy needs are primarily being met with fossil fuel plants in both developed and developing nations. Although it is unlikely to entirely replace fossil fuel systems, the incorporation of alternative energy systems that produce fewer emissions and utilize fewer resources may prove useful in furthering sustainable energy practices. Nuclear and Renewable Energy Integration (NREI) represents one potential, alternative system and is comprised of both nuclear and renewable technologies coupled with energy storage and industrial process heat applications. This article reviews the fundamentals of sustainability and its drivers, defines the necessary scope for analyzing energy systems, details widely used sustainabilitymore » metrics, and assesses sustainability through the sustainability efficiency factor (SEF) based on the core pillars of economy, environment, and society—all of which aim to promote future sustainable development. The assessment is performed for an NREI system comprised of a small modular reactor (SMR), where a portion of the heat generated is utilized for hydrogen production through high-temperature steam electrolysis (HTSE). The global warming potential for NREI is compared to the typical emissions observed for hydrogen production via steam methane reforming and are estimated to yield 92.6% fewer grams of CO 2-equivalent per kilogram of hydrogen produced. Furthermore, the calculated SEF for NREI is 22.2% higher than steam methane reforming. Because SMR designs are at varying design, developmental, and deployment stages, a method of estimating economics is presented to demonstrate the differences observed between first-of-a-kind (FOAK) and nth-of-a-kind (NOAK) units, as well as the resulting total capital investment cost. Lastly, a comprehensive list of considerations necessary for future energy system development was enumerated based on four core assessment areas: technical feasibility, environmental impact, economic feasibility and impact, and socio-political impacts.« less

Tin recovery from tin slag using electrolysis method

NASA Astrophysics Data System (ADS)

Jumari, Arif; Purwanto, Agus; Nur, Adrian; Budiman, Annata Wahyu; Lerian, Metty; Paramita, Fransisca A.

2018-02-01

The process in industry, including in mining industry, would surely give negative effect such as waste polluting to the environment. Some of waste could be potentially reutilized to be a commodity with the higher economic value. Tin slag is one of them. The aim of this research was to recover the tin contained in tin slag. Before coming to the electrolysis, tin slag must be treated by dissolution. The grinded tin slag was dissolved into HCl solution to form a slurry. During dissolution, the slurry was agitated and heated, and finally filtered. The filtrate obtained was then electrolyzed. During the process of electrolysis, solid material precipitated on the used cathode. The precipitated solid was then separated and dried. The solid was then analyzed using XRD, XRF and SEM. The XRD analysis showed that the longest time of dissolution and electrolysis the highest the purity obtained in the product. The SEM analysis showed that the longest time of electrolysis the smallest tin particle obtained. Optimum time achieved in this research was 2 hours for the recovering time and 3 hours for the electrolysis time, with 9% tin recovered.

A review of high temperature co-electrolysis of H2O and CO2 to produce sustainable fuels using solid oxide electrolysis cells (SOECs): advanced materials and technology.

PubMed

Zheng, Yun; Wang, Jianchen; Yu, Bo; Zhang, Wenqiang; Chen, Jing; Qiao, Jinli; Zhang, Jiujun

2017-03-06

High-temperature solid oxide electrolysis cells (SOECs) are advanced electrochemical energy storage and conversion devices with high conversion/energy efficiencies. They offer attractive high-temperature co-electrolysis routes that reduce extra CO 2 emissions, enable large-scale energy storage/conversion and facilitate the integration of renewable energies into the electric grid. Exciting new research has focused on CO 2 electrochemical activation/conversion through a co-electrolysis process based on the assumption that difficult C[double bond, length as m-dash]O double bonds can be activated effectively through this electrochemical method. Based on existing investigations, this paper puts forth a comprehensive overview of recent and past developments in co-electrolysis with SOECs for CO 2 conversion and utilization. Here, we discuss in detail the approaches of CO 2 conversion, the developmental history, the basic principles, the economic feasibility of CO 2 /H 2 O co-electrolysis, and the diverse range of fuel electrodes as well as oxygen electrode materials. SOEC performance measurements, characterization and simulations are classified and presented in this paper. SOEC cell and stack designs, fabrications and scale-ups are also summarized and described. In particular, insights into CO 2 electrochemical conversions, solid oxide cell material behaviors and degradation mechanisms are highlighted to obtain a better understanding of the high temperature electrolysis process in SOECs. Proposed research directions are also outlined to provide guidelines for future research.

New, Efficient, and Reliable Air Electrode Material for Proton-Conducting Reversible Solid Oxide Cells.

PubMed

Huan, Daoming; Shi, Nai; Zhang, Lu; Tan, Wenzhou; Xie, Yun; Wang, Wanhua; Xia, Changrong; Peng, Ranran; Lu, Yalin

2018-01-17

Driven by the demand to minimize fluctuation in common renewable energies, reversible solid oxide cells (RSOCs) have drawn increasing attention for they can operate either as fuel cells to produce electricity or as electrolysis cells to store electricity. Unfortunately, development of proton-conducting RSOCs (P-RSOCs) faces a major challenge of poor reliability because of the high content of steam involved in air electrode reactions, which could seriously decay the lifetime of air electrode materials. In this work, a very stable and efficient air electrode, SrEu 2 Fe 1.8 Co 0.2 O 7-δ (SEFC) with layer structure, is designed and deployed in P-RSOCs. X-ray diffraction analysis and High-angle annular dark-filed scanning transmission electron microscopy images of SEFC reveal that Sr atoms occupy the center of perovskite slabs, whereas Eu atoms arrange orderly in the rock-salt layer. Such a special structure of SEFC largely depresses its Lewis basicity and therefore its reactivity with steam. Applying the SEFC air electrode, our button switches smoothly between both fuel cell and electrolysis cell (EC) modes with no obvious degradation over a 135 h long-term test under wet H 2 (∼3% H 2 O) and 10% H 2 O-air atmospheres. A record of over 230 h is achieved in the long-term stability test in the EC mode, doubling the longest test that had been previously reported. Besides good stability, SEFC demonstrates great catalytic activity toward air electrode reactions when compared with traditional La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ air electrodes. This research highlights the potential of stable and efficient P-RSOCs as an important part in a sustainable new energy power system.

Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process

DOE PAGES

Lewis, Alex J.; Ren, Shoujie; Ye, Philip; ...

2015-06-30

A new approach to hydrogen production using a hybrid pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50 3.2% to76 0.5% while anode coulombic efficiency ranged from 54 6.5% to 96 0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%,more » respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass.« less

Express Electrolysis.

ERIC Educational Resources Information Center

Smithenry, Dennis; Gassman, Christopher; Goodridge, Brandon; Petersen, Tom

1998-01-01

Explains the process of student and teacher collaboration on a project to develop a faster electrolysis mechanism. Provides a good example of the problem-based approach to science instruction and curriculum. (DDR)

Conditioning of sewage sludge with electrolysis: effectiveness and optimizing study to improve dewaterability.

PubMed

Yuan, Haiping; Zhu, Nanwen; Song, Lijie

2010-06-01

The potential benefits of electrolysis-conditioned sludge dewatering treatment were investigated in this paper. Focuses were placed on effectiveness and factors affecting such novel application of electrolysis process. Experiments have demonstrated that a significant improvement of sludge dewaterability evaluated by capillary suction time (CST) could be obtained at a relative low value of electrolysis voltage. A Box-Behnken experimental design based on the response surface methodology (RSM) was applied to evaluate the optimum of the influencing variables. The optimal values for electrolysis voltage, electrode distance and electrolysis time are 21 V, 5 cm and 12 min, respectively, at which the CST reduction efficiency of 18.8+/-3.1% could be achieved, this agreed with that predicted by an established polynomial model in this study. (c) 2010 Elsevier Ltd. All rights reserved.

Simulation of isoelectro focusing processes. [stationary electrolysis of charged species

NASA Technical Reports Server (NTRS)

Palusinski, O. A.

1980-01-01

This paper presents the computer implementation of a model for the stationary electrolysis of two or more charged species. This has specific application to the technique of isoelectric focussing, in which the stationary electrolysis of ampholytes is used to generate a pH gradient useful for the separation of proteins, peptides and other biomolecules. The fundamental equations describing the process are given. These equations are transformed to a form suitable for digital computer implementation. Some results of computer simulation are described and compared to data obtained in the laboratory.

Electrolysis with diamond anodes: Eventually, there are refractory species!

PubMed

Mena, Ismael F; Cotillas, Salvador; Díaz, Elena; Sáez, Cristina; Rodríguez, Juan J; Cañizares, P; Mohedano, Ángel F; Rodrigo, Manuel A

2018-03-01

In this work, synthetic wastewater polluted with ionic liquid 1-butyl-3-methylimidazolium (Bmim) bis(trifluoromethanesulfonyl)imide (NTf 2 ) undergoes four electrolytic treatments with diamond anodes (bare electrolysis, electrolysis enhanced with peroxosulfate promoters, irradiated with UV light and with US) and results obtained were compared with those obtained with the application of Catalytic Wet Peroxide Oxidation (CWPO). Despite its complex heterocyclic structure, Bmim + cation is successfully depleted with the five technologies tested, being transformed into intermediates that eventually can be mineralized. Photoelectrolysis attained the lowest concentration of intermediates, while CWPO is the technology less efficient in their degradation. However, the most surprising result is that concentration of NTf 2 - anion does not change during the five advanced oxidation processes tested, pointing out its strong refractory character, being the first species that exhibits this character in wastewater undergoing electrolysis with diamond. This means that the hydroxyl and sulfate radicals mediated oxidation and the direct electrolysis are inefficient for breaking the C-S, C-F and S-N bounds of the NTf 2 - anion, which is a very interesting mechanistic information to understand the complex processes undergone in electrolysis with diamond. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater

PubMed Central

Yang, Ruihong; ZHU, Jianzhong; Li, Yingliu; Zhang, Hui

2016-01-01

Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na2SO4 additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography–mass spectrometry (GC–MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet–visible spectroscopy (UV–VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency. PMID:27136574

A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater.

PubMed

Yang, Ruihong; Zhu, Jianzhong; Li, Yingliu; Zhang, Hui

2016-04-29

Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na₂SO₄ additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography-mass spectrometry (GC-MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet-visible spectroscopy (UV-VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency.

Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

PubMed

Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

2017-10-01

Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

Hydrogen Transport to Mars Enables the Sabatier/Electrolysis Process

NASA Technical Reports Server (NTRS)

Mueller, P. J.; Rapp, D.

1997-01-01

The Sabatier/Electrolysis (S/E) process is an attractive approach to in situ propellant production (ISPP), and a breadboard demonstration of this process at Lockheed Martin Astronautics funded by JPL performed very well, with high conversion efficiency, and reliable diurnal operation. There is a net usage of hydrogen in the S/E process, and this has been the principal problem for this approach to ISPP.

The Effect of Converting to a U.S. Hydrogen Fuel Cell Vehicle Fleet on Emissions and Energy Use

NASA Astrophysics Data System (ADS)

Colella, W. G.; Jacobson, M. Z.; Golden, D. M.

2004-12-01

This study analyzes the potential change in emissions and energy use from replacing fossil-fuel based vehicles with hydrogen fuel cell vehicles. This study examines three different hydrogen production scenarios to determine their resultant emissions and energy usage: hydrogen produced via 1) steam reforming of methane, 2) coal gasification, or 3) wind electrolysis. The atmospheric model simulations require two primary sets of data: the actual emissions associated with hydrogen fuel production and use, and the corresponding reduction in emissions associated with reducing fossil fuel use. The net change in emissions is derived using 1) the U.S. EPA's National Emission Inventory (NEI) that incorporates several hundred categories of on-road vehicles and 2) a Process Chain Analysis (PCA) for the different hydrogen production scenarios. NEI: The quantity of hydrogen-related emission is ultimately a function of the projected hydrogen consumption in on-road vehicles. Data for hydrogen consumption from on-road vehicles was derived from the number of miles driven in each U.S. county based on 1999 NEI data, the average fleet mileage of all on-road vehicles, the average gasoline vehicle efficiency, and the efficiency of advanced 2004 fuel cell vehicles. PCA: PCA involves energy and mass balance calculations around the fuel extraction, production, transport, storage, and delivery processes. PCA was used to examine three different hydrogen production scenarios: In the first scenario, hydrogen is derived from natural gas, which is extracted from gas fields, stored, chemically processed, and transmitted through pipelines to distributed fuel processing units. The fuel processing units, situated in similar locations as gasoline refueling stations, convert natural gas to hydrogen via a combination of steam reforming and fuel oxidation. Purified hydrogen is compressed for use onboard fuel cell vehicles. In the second scenario, hydrogen is derived from coal, which is extracted from mines and chemically processed into a hydrogen rich gas. Hydrogen is transmitted through pipelines to refueling stations. In the third scenario, hydrogen is derived via electrolysis powered by wind-generated electricity that has been transmitted across the country to electrolyzers at distributed hydrogen refueling stations. If hydrogen is produced via the first scenario, total annual U.S. production of carbon dioxide (CO2) could be expected to decrease by approximately 900 million metric tons, or 16 percent of annual U.S. CO2 production from all anthropogenic sources. Under this scenario, compared with the conventional vehicle fleet, a fuel cell vehicle fleet would produce some additional CO2 emissions due to the electric power required for the compression of hydrogen, but less CO2 emissions on the road during vehicle operation. This scenario results in an additional methane leakage of approximately one million metric tons per year, or 4 percent of annual U.S. methane emissions from all anthropogenic sources.

Hydrogen Generation by Koh-Ethanol Plasma Electrolysis Using Double Compartement Reactor

NASA Astrophysics Data System (ADS)

Saksono, Nelson; Sasiang, Johannes; Dewi Rosalina, Chandra; Budikania, Trisutanti

2018-03-01

This study has successfully investigated the generation of hydrogen using double compartment reactor with plasma electrolysis process. Double compartment reactor is designed to achieve high discharged voltage, high concentration, and also reduce the energy consumption. The experimental results showed the use of double compartment reactor increased the productivity ratio 90 times higher compared to Faraday electrolysis process. The highest hydrogen production obtained is 26.50 mmol/min while the energy consumption can reach up 1.71 kJ/mmol H2 at 0.01 M KOH solution. It was shown that KOH concentration, addition of ethanol, cathode depth, and temperature have important effects on hydrogen production, energy consumption, and process efficiency.

Hydrogen production from switchgrass via an integrated pyrolysis-microbial electrolysis process.

PubMed

Lewis, A J; Ren, S; Ye, X; Kim, P; Labbe, N; Borole, A P

2015-11-01

A new approach to hydrogen production using an integrated pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L anode-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50±3.2% to 76±0.5% while anode Coulombic efficiency ranged from 54±6.5% to 96±0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%, respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stainless steel anodes for alkaline water electrolysis and methods of making

DOEpatents

Soloveichik, Grigorii Lev

2014-01-21

The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

Coproduction of volatiles and metals from extraterrestrial materials

NASA Technical Reports Server (NTRS)

Lewis, John S.

1991-01-01

Two main efforts in support of the general goals of SERC/culpr are presented. Investigations of processes for the coproduction of metals from extra-terrestrial materials in conjunction with plausible schemes for oxygen extraction continue. The principal emphasis was on the extraction and purification of iron from the ilmenite reduction process for oxygen, from the cathode metal deposits made in the magma electrolysis process for oxygen, and from native ferrous metal alloys on the moon and asteroids. All work on the separation and purification of ferrous metals was focussed upon the gaseous carbonyl process, a scheme that involves only temperatures attainable by passive thermal control. The exploration of a variety of schemes was initiated, involving the use of several different propulsion options and both propulsive and aerobraking capture at earth, for return of extraterrestrial resources to earth orbits. In addition, the search for new opportunities in space resource utilization continues. Examples include the continuation of work underway on: (1) the feasibility of locating solar power satellites in highly eccentric earth orbit; (2) the energetics of extracting the potential clean fusion fuel He-3 from the atmosphere for return to earth; and (3) the utility of a nuclear steam rocket (using non-terrestrial water as the working fluid) for transportation in the inner solar system.

Solid oxide membrane (SOM) process for ytterbium and silicon production from their oxides

NASA Astrophysics Data System (ADS)

Jiang, Yihong

The Solid oxide membrane (SOM) electrolysis is an innovative green technology that produces technologically important metals directly from their respective oxides. A yttria-stabilized zirconia (YSZ) tube, closed at one end is employed to separate the molten salt containing dissolved metal oxides from the anode inside the YSZ tube. When the applied electric potential between the cathode in the molten salt and the anode exceeds the dissociation potential of the desired metal oxides, oxygen ions in the molten salt migrate through the YSZ membrane and are oxidized at the anode while the dissolved metal cations in the flux are reduced to the desired metal at the cathode. Compared with existing metal production processes, the SOM process has many advantages such as one unit operation, less energy consumption, lower capital costs and zero carbon emission. Successful implementation of the SOM electrolysis process would provide a way to mitigate the negative environmental impact of the metal industry. Successful demonstration of producing ytterbium (Yb) and silicon (Si) directly from their respective oxides utilizing the SOM electrolysis process is presented in this dissertation. During the SOM electrolysis process, Yb2O3 was reduced to Yb metal on an inert cathode. The melting point of the supporting electrolyte (LiF-YbF3-Yb2O3) was determined by differential thermal analysis (DTA). Static stability testing confirmed that the YSZ tube was stable with the flux at operating temperature. Yb metal deposit on the cathode was confirmed by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). During the SOM electrolysis process for silicon production, a fluoride based flux based on BaF2, MgF2, and YF3 was engineered to serve as the liquid electrolyte for dissolving silicon dioxide. YSZ tube was used to separate the molten salt from an anode current collector in the liquid silver. Liquid tin was chosen as cathode to dissolve the reduced silicon during SOM electrolysis. After electrolysis, upon cooling, silicon crystals precipitated out from the Si-Sn liquid alloy. The presence of high-purity silicon crystals in the liquid tin cathode was confirmed by SEM/EDS. The fluoride based flux was also optimized to improve YSZ membrane stability for long-term use.

Enhanced hydroxyl radical generation in the combined ozonation and electrolysis process using carbon nanotubes containing gas diffusion cathode.

PubMed

Wu, Donghai; Lu, Guanghua; Zhang, Ran; Lin, Qiuhong; Yan, Zhenhua; Liu, Jianchao; Li, Yi

2015-10-01

Combination of ozone together with electrolysis (ozone-electrolysis) is a promising wastewater treatment technology. This work investigated the potential use of carbon nanotube (CNT)-based gas diffusion cathode (GDC) for ozone-electrolysis process employing hydroxyl radicals (·OH) production as an indicator. Compared with conventional active carbon (AC)-polytetrafluoroethylene (PTFE) and carbon black (CB)-PTFE cathodes, the production of ·OH in the coupled process was improved using CNTs-PTFE GDC. Appropriate addition of acetylene black (AB) and pore-forming agent Na2SO4 could enhance the efficiency of CNTs-PTFE GDC. The optimum GDC composition was obtained by response surface methodology (RSM) analysis and was determined as CNTs 31.2 wt%, PTFE 60.6 wt%, AB 3.5 wt%, and Na2SO4 4.7 wt%. Moreover, the optimized CNT-based GDC exhibited much more effective than traditional Ti and graphite cathodes in Acid Orange 7 (AO7) mineralization and possessed the desirable stability without performance decay after ten times reaction. The comparison tests revealed that peroxone reaction was the main pathway of ·OH production in the present system, and cathodic reduction of ozone could significantly promote ·OH generation. These results suggested that application of CNT-based GDC offers considerable advantages in ozone-electrolysis of organic wastewater.

Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

James E. O'Brien; Carl M. Stoots; J. Stephen Herring

2006-04-01

This paper presents the technical case for high-temperature nuclear hydrogen production. A general thermodynamic analysis of hydrogen production based on high-temperature thermal water splitting processes is presented. Specific details of hydrogen production based on high-temperature electrolysis are also provided, including results of recent experiments performed at the Idaho National Laboratory. Based on these results, high-temperature electrolysis appears to be a promising technology for efficient large-scale hydrogen production.

Electroslag Treatment of Liquid Cast Iron

NASA Astrophysics Data System (ADS)

Grachev, V. A.

2018-01-01

The processes that occur in the liquid metal-slag system during electroslag treatment of cast iron are studied from an electrochemical standpoint. The role of electrolysis in the electroslag process is shown, and a method for producing high-strength cast iron with globular graphite using electrolysis of a slag containing magnesium oxides and fluorides is proposed and tested.

[Processes of adaptogenesis and heart remodelling in workers of electrolysis workshops in aluminum plants].

PubMed

Khasanova, G N; Oranskiĭ, I E; Roslaia, N A

2010-01-01

Workers in electrolysis workshops of aluminium plants demonstrate changes in intracardial hemodynamics and left ventricle diastolic function, heart remodelling to concentric and excentric hypertrophy, more in individuals with chronic occupational fluorine intoxication.

Computer simulation of the NASA water vapor electrolysis reactor

NASA Technical Reports Server (NTRS)

Bloom, A. M.

1974-01-01

The water vapor electrolysis (WVE) reactor is a spacecraft waste reclamation system for extended-mission manned spacecraft. The WVE reactor's raw material is water, its product oxygen. A computer simulation of the WVE operational processes provided the data required for an optimal design of the WVE unit. The simulation process was implemented with the aid of a FORTRAN IV routine.

Multi-Physics Modeling of Molten Salt Transport in Solid Oxide Membrane (SOM) Electrolysis and Recycling of Magnesium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, Adam; Pati, Soobhankar

2012-03-11

Solid Oxide Membrane (SOM) Electrolysis is a new energy-efficient zero-emissions process for producing high-purity magnesium and high-purity oxygen directly from industrial-grade MgO. SOM Recycling combines SOM electrolysis with electrorefining, continuously and efficiently producing high-purity magnesium from low-purity partially oxidized scrap. In both processes, electrolysis and/or electrorefining take place in the crucible, where raw material is continuously fed into the molten salt electrolyte, producing magnesium vapor at the cathode and oxygen at the inert anode inside the SOM. This paper describes a three-dimensional multi-physics finite-element model of ionic current, fluid flow driven by argon bubbling and thermal buoyancy, and heat andmore » mass transport in the crucible. The model predicts the effects of stirring on the anode boundary layer and its time scale of formation, and the effect of natural convection at the outer wall. MOxST has developed this model as a tool for scale-up design of these closely-related processes.« less

Magnetic Resonance Imaging of Electrolysis.

PubMed Central

Meir, Arie; Hjouj, Mohammad; Rubinsky, Liel; Rubinsky, Boris

2015-01-01

This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. We further demonstrate the biological relevance of our work using a bacterial E. Coli model, grown on the phantom. The results demonstrate the ability of MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research. PMID:25659942

Research on the use of space resources

NASA Technical Reports Server (NTRS)

Carroll, W. F. (Editor)

1983-01-01

The second year of a multiyear research program on the processing and use of extraterrestrial resources is covered. The research tasks included: (1) silicate processing, (2) magma electrolysis, (3) vapor phase reduction, and (4) metals separation. Concomitant studies included: (1) energy systems, (2) transportation systems, (3) utilization analysis, and (4) resource exploration missions. Emphasis in fiscal year 1982 was placed on the magma electrolysis and vapor phase reduction processes (both analytical and experimental) for separation of oxygen and metals from lunar regolith. The early experimental work on magma electrolysis resulted in gram quantities of iron (mixed metals) and the identification of significant anode, cathode, and container problems. In the vapor phase reduction tasks a detailed analysis of various process concepts led to the selection of two specific processes designated as ""Vapor Separation'' and ""Selective Ionization.'' Experimental work was deferred to fiscal year 1983. In the Silicate Processing task a thermophysical model of the casting process was developed and used to study the effect of variations in material properties on the cooling behavior of lunar basalt.

Lunar production of oxygen by electrolysis

NASA Technical Reports Server (NTRS)

Keller, Rudolf

1991-01-01

Two approaches to prepare oxygen from lunar resources by direct electrolysis are discussed. Silicates can be melted or dissolved in a fused salt and electrolyzed with oxygen evolved at the anode. Direct melting and electrolysis is potentially a very simple process, but high temperatures of 1400-1500 C are required, which aggravates materials problems. Operating temperatures can be lowered to about 1000 C by employing a molten salt flux. In this case, however, losses of electrolyte components must be avoided. Experimentation on both approaches is progressing.

Modelling of fluoride removal via batch monopolar electrocoagulation process using aluminium electrodes

NASA Astrophysics Data System (ADS)

Amri, N.; Hashim, M. I.; Ismail, N.; Rohman, F. S.; Bashah, N. A. A.

2017-09-01

Electrocoagulation (EC) is a promising technology that extensively used to remove fluoride ions efficiently from industrial wastewater. However, it has received very little consideration and understanding on mechanism and factors that affecting the fluoride removal process. In order to determine the efficiency of fluoride removal in EC process, the effect of operating parameters such as voltage and electrolysis time were investigated in this study. A batch experiment with monopolar aluminium electrodes was conducted to identify the model of fluoride removal using empirical model equation. The EC process was investigated using several parameters which include voltage (3 - 12 V) and electrolysis time (0 - 60 minutes) at a constant initial fluoride concentration of 25 mg/L. The result shows that the fluoride removal efficiency increased steadily with increasing voltage and electrolysis time. The best fluoride removal efficiency was obtained with 94.8 % removal at 25 mg/L initial fluoride concentration, voltage of 12 V and 60 minutes electrolysis time. The results indicated that the rate constant, k and number of order, n decreased as the voltage increased. The rate of fluoride removal model was developed based on the empirical model equation using the correlation of k and n. Overall, the result showed that EC process can be considered as a potential alternative technology for fluoride removal in wastewater.

Oxygen from the lunar soil by molten silicate electrolysis

NASA Technical Reports Server (NTRS)

Colson, Russell O.; Haskin, Larry A.

1992-01-01

Accepting that oxygen, rather than gigantic gems or gold, is likely to make the Moon's Klondike, the extraction of oxygen from the lunar soil by molten silicate electrolysis has chosen to be investigated. Process theory and proposed lunar factory are addressed.

Electrolysis of metal oxides in MgCl2 based molten salts with an inert graphite anode.

PubMed

Yuan, Yating; Li, Wei; Chen, Hualin; Wang, Zhiyong; Jin, Xianbo; Chen, George Z

2016-08-15

Electrolysis of solid metal oxides has been demonstrated in MgCl2-NaCl-KCl melt at 700 °C taking the electrolysis of Ta2O5 as an example. Both the cathodic and anodic processes have been investigated using cyclic voltammetry, and potentiostatic and constant voltage electrolysis, with the cathodic products analysed by XRD and SEM and the anodic products by GC. Fast electrolysis of Ta2O5 against a graphite anode has been realized at a cell voltage of 2 V, or a total overpotential of about 400 mV. The energy consumption was about 1 kW h kgTa(-1) with a nearly 100% Ta recovery. The cathodic product was nanometer Ta powder with sizes of about 50 nm. The main anodic product was Cl2 gas, together with about 1 mol% O2 gas and trace amounts of CO. The graphite anode was found to be an excellent inert anode. These results promise an environmentally-friendly and energy efficient method for metal extraction by electrolysis of metal oxides in MgCl2 based molten salts.

Kinetic modelling of methane production during bio-electrolysis from anaerobic co-digestion of sewage sludge and food waste.

PubMed

Prajapati, Kalp Bhusan; Singh, Rajesh

2018-05-10

In present study batch tests were performed to investigate the enhancement in methane production under bio-electrolysis anaerobic co-digestion of sewage sludge and food waste. The bio-electrolysis reactor system (B-EL) yield more methane 148.5 ml/g COD in comparison to reactor system without bio-electrolysis (B-CONT) 125.1 ml/g COD. Whereas bio-electrolysis reactor system (C-EL) Iron Scraps amended yield lesser methane (51.2 ml/g COD) in comparison to control bio-electrolysis reactor system without Iron scraps (C-CONT - 114.4 ml/g COD). Richard and Exponential model were best fitted for cumulative methane production and biogas production rates respectively as revealed modelling study. The best model fit for the different reactors was compared by Akaike's Information Criterion (AIC) and Bayesian Information Criterion (BIC). The bioelectrolysis process seems to be an emerging technology with lesser the loss in cellulase specific activity with increasing temperature from 50 to 80 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

Options for refuelling hydrogen fuel cell vehicles in Italy

NASA Astrophysics Data System (ADS)

Mercuri, R.; Bauen, A.; Hart, D.

Hydrogen fuel cell vehicle (H 2 FCV) trials are taking place in a number of cities around the world. In Italy, Milan and Turin are the first to have demonstration projects involving hydrogen-fuelled vehicles, in part to satisfy increasing consumer demand for improved environmental performance. The Italian transport plan specifically highlights the potential for FCVs to enter into the marketplace from around 2005. A scenario for FCV penetration into Italy, developed using projected costs for FCV and hydrogen fuel, suggests that by 2015, 2 million Italian cars could be powered by fuel cells. By 2030, 60% of the parc could be FCVs. To develop an infrastructure to supply these vehicles, a variety of options is considered. Large-scale steam reforming, on-site reforming and electrolysis options are analysed, with hydrogen delivered both in liquid and gaseous form. Assuming mature technologies, with over 10,000 units produced, on-site steam reforming provides the most economic hydrogen supply to the consumer, at US 2.6/kg. However, in the early stages of the infrastructure development there is a clear opportunity for on-site electrolysis and for production of hydrogen at centralised facilities, with delivery in the form of liquid hydrogen. This enables additional flexibility, as the hydrogen may also be used for fuel refining or for local power generation. In the current Italian context, energy companies could have a significant role to play in developing a hydrogen infrastructure. The use of hydrogen FCVs can substantially reduce emissions of regulated pollutants and greenhouse gases. Using externality costs for regulated pollutants, it is estimated that the use of hydrogen fuel cell buses in place of 5% of diesel buses in Milan could avoid US 2 million per year in health costs. The addition of even very low externality costs to fuel prices makes the use of untaxed hydrogen in buses and cars, which is slightly more expensive for the motorist than untaxed gasoline or diesel, competitive on a social cost basis.

System Evaluation and Economic Analysis of a HTGR Powered High-Temperature Electrolysis Hydrogen Production Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael G. McKellar; Edwin A. Harvego; Anastasia A. Gandrik

2010-10-01

A design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The power conversion unit will be a Rankine steam cycle with a power conversion efficiency of 40%. The reference hydrogen production plantmore » operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 40.4% at a hydrogen production rate of 1.75 kg/s and an oxygen production rate of 13.8 kg/s. An economic analysis of this plant was performed with realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.67/kg of hydrogen assuming an internal rate of return, IRR, of 12% and a debt to equity ratio of 80%/20%. A second analysis shows that if the power cycle efficiency increases to 44.4%, the hydrogen production efficiency increases to 42.8% and the hydrogen and oxygen production rates are 1.85 kg/s and 14.6 kg/s respectively. At the higher power cycle efficiency and an IRR of 12% the cost of hydrogen production is $3.50/kg.« less

Trade Study of Five In-Situ Propellant Production Systems for a Mars Sample Return Mission

NASA Technical Reports Server (NTRS)

Green, S. T.; Deffenbaugh, D. M.; Miller, M. A.

1999-01-01

One of the goals of NASA's HEDS enterprise is to establish a long-term human presence on Mars at a fraction of the cost of employing today's technology. The most direct method of reducing mission cost is to reduce the launch mass of the spacecraft. If the propellants for the return phase of the mission are produced on Mars, the total spacecraft mass could be reduced significantly. An interim goal is a Mars Sample Return (MSR) mission, which is proposed to demonstrate the feasibility of in-situ propellant production (ISPP). Five candidate ISPP systems for producing two fuels and oxygen from the Martian atmosphere are considered in this design trade-off study: 1) Zirconia cell with methanol synthesis, 2) Reverse water gas shift with water electrolysis and methanol synthesis, 3) Sabatier process for methane product ion with water electrolysis, 4) Sabatier process with water electrolysis and partial methane pyrolysis, and 5) Sabatier/RWGS combination with water electrolysis.

Contact Electrification of Regolith Particles and Chloride Electrolysis: Synthesis of Perchlorates on Mars.

PubMed

Tennakone, K

2016-10-01

Contact electrification of chloride-impregnated martian regolith particles due to eolian agitation and moisture condensation on coalesced oppositely charged grains may lead to spontaneous electrolysis that generates hypochlorite, chlorite, chlorate, and perchlorate with a concomitant reduction of water to hydrogen. This process is not curtailed even if moisture condenses as ice because chloride ionizes on the surface of ice. Limitations dictated by potentials needed for electrolysis and breakdown electric fields enable estimation of the required regolith grain size. The estimated dimension turns out to be of the same order of magnitude as the expected median size of martian regolith, and a simple calculation yields the optimum rate of perchlorate production. Key Words: Mars oxidants-Perchlorate-Dust electrification-Electrolysis. Astrobiology 16, 811-816.

Natural gas anodes for aluminium electrolysis in molten fluorides.

PubMed

Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

2016-08-15

Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process.

Novel electrical energy storage system based on reversible solid oxide cells: System design and operating conditions

NASA Astrophysics Data System (ADS)

Wendel, C. H.; Kazempoor, P.; Braun, R. J.

2015-02-01

Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges and questions from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. This paper presents a novel system based on ReSOCs that employ a thermal management strategy of promoting exothermic methanation within the ReSOC cell-stack to provide thermal energy for the endothermic steam/CO2 electrolysis reactions during charging mode (fuel producing). This approach also serves to enhance the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a physically based ReSOC stack model coupled with thermodynamic system component models. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (680 °C) and elevated stack pressure (20 bar). The optimal operating condition arises from a tradeoff between stack efficiency and auxiliary power requirements from balance of plant hardware.

Determination of the Electronics Charge--Electrolysis of Water Method.

ERIC Educational Resources Information Center

Venkatachar, Arun C.

1985-01-01

Presents an alternative method for measuring the electronic charge using data from the electrolysis of acidified distilled water. The process (carried out in a commercially available electrolytic cell) has the advantage of short completion time so that students can determine electron charge and mass in one laboratory period. (DH)

Computer-aided control of electrolysis of solid Nb2O5 in molten CaCl2.

PubMed

Wu, Tian; Xiao, Wei; Jin, Xianbo; Liu, Chao; Wang, Dihua; Chen, George Z

2008-04-07

Low energy production of Nb powders via computer-aided control (CAC) of two-electrode electrolysis of porous Nb2O5 pellets (ca. 1.0 g) has been successfully demonstrated in molten CaCl2 at 1123 K. It was observed that potentiostatic electrolysis of the oxide in a three-electrode cell led to a cell voltage, i.e. the potential difference between the working (cathode) and counter (anode) electrodes, that decreased to a low and stable value within 1-2 h of the potential application until the end of the electrolysis (up to 12 h in this work). The cell voltage varied closely according to the current change. The stabilised cell voltage was below 2.5 V when the cathode potential was more positive than that for the reduction of Ca2+, leading to much lower energy consumption than that of constant voltage (>3.0 V) two-electrode electrolysis, as previously reported. Using a computer to program the variation of the cell voltage of two-electrode electrolysis according to that observed in the potentiostatic three-electrode electrolysis (0.05 V vs. Ca/Ca2+), a Nb powder with ca. 3900 ppm oxygen was produced in 12 h, with the energy consumption being 37.4% less than that of constant voltage two-electrode electrolysis at 3.0 V. Transmission electron microscopy revealed thin oxide layers (4-6 nm) on individual nodular particles (1-5 microm) of the obtained Nb powder. The oxide layer was likely formed in post-electrolysis processing operations, including washing in water, and contributed largely to the oxygen content in the obtained Nb powder.

Solid electrolyte fuel cells

NASA Astrophysics Data System (ADS)

Isaacs, H. S.

Progress in the development of functioning solid electrolyte fuel cells is summarized. The solid electrolyte cells perform at 1000 C, a temperature elevated enough to indicate high efficiencies are available, especially if the cell is combined with a steam generator/turbine system. The system is noted to be sulfur tolerant, so coal containing significant amounts of sulfur is expected to yield satisfactory performances with low parasitic losses for gasification and purification. Solid oxide systems are electrically reversible, and are usable in both fuel cell and electrolysis modes. Employing zirconium and yttrium in the electrolyte provides component stability with time, a feature not present with other fuel cells. The chemical reactions producing the cell current are reviewed, along with materials choices for the cathodes, anodes, and interconnections.

[Measurement of pancreatic microcirculation using hydrogen gas generated by electrolysis in dogs].

PubMed

Nishiwaki, H; Satake, K; Ko, I; Tanaka, H; Kanazawa, G; Nagai, Y; Umeyama, K

1986-11-01

Measurements of pancreatic microflow were investigated using hydrogen gas generated by electrolysis in dog. After laparatomy under general anesthesia, uncinate process of the pancreas was punctured by a needle electrode for electrolysis and determination of hydrogen gas. The consecutive measurements of pancreatic microflow revealed the good reproducibility at the same point of the pancreas. The simultaneous measurements of pancreatic microflow by electrolysis and pancreatic tissue blood flow by H2 inhalation method were carried out at the same point of the pancreas. Correlation analysis of both measurements revealed coefficient of 0.751 and a significant relationship was observed (p less than 0.05). However, the value was a little higher in pancreatic microflow as compared with pancreatic tissue blood flow. Pancreatic microflow and pancreatic exocrine secretion increased after intravenous administration of Dopamine and Secretin (10 micrograms/kg/min). It is concluded that the measurement of pancreatic microflow by hydrogen gas generated by electrolysis is a useful method on understanding the microcirculation of the pancreas.

Electrolysis of lunar soil to produce oxygen and metals

NASA Technical Reports Server (NTRS)

Colson, Russell O.; Haskin, Larry A.; Keller, R.

1991-01-01

The discussion of melt electrolysis consists of three sections. The implications of the chemistry and physics of fluxed and raw melts on melt electrolysis are discussed first. This includes discussion of the factor that influence melt resistivity, melt viscosity, oxygen production efficiency, and the theoretical energy required to produce oxygen. Second, the implications of phase equilibria and solubilities in silicate melts on the selection of materials for container and electrodes are discussed. The implications of proposed container and electrode materials on melt composition and how this effects expected resistivities, viscosities, as outlined in the first section are discussed. Finally, a general discussion of the basic features of both the fluxed and unfluxed melt electrolysis is given, including their advantages and disadvantages and how they compare with alternative processes.

Field-scale electrolysis/ceramic membrane system for the treatment of sewage from decentralized small communities.

PubMed

Son, Dong-Jin; Kim, Woo-Yeol; Yun, Chan-Young; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

2017-07-05

The electrolysis process adopting copper electrodes and ceramic membrane with pore sizes of 0.1-0.2 μm were consisted to a system for the treatment of sewage from decentralized small communities. The system was operated under an HRT of 0.1 hour, voltage of 24 V, and TMP of 0.05 MPa. The system showed average removals of organics, nitrogen, phosphorus, and solids of up to 80%, 52%, 92%, and 100%, respectively. Removal of organics and nitrogen dramatically increased in proportion to increment of influent loading. Phosphorus and solids were remarkably eliminated by both electro-coagulation and membrane filtration. The residual particulate constituents could also be removed successfully through membrane process. A system composed of electrolysis process with ceramic membrane would be a compact, reliable, and flexible option for the treatment of sewage from decentralized small communities.

A model-based understanding of solid-oxide electrolysis cells (SOECs) for syngas production by H2O/CO2 co-electrolysis

NASA Astrophysics Data System (ADS)

Menon, Vikram; Fu, Qingxi; Janardhanan, Vinod M.; Deutschmann, Olaf

2015-01-01

High temperature co-electrolysis of H2O and CO2 offers a promising route for syngas (H2, CO) production via efficient use of heat and electricity. The performance of a SOEC during co-electrolysis is investigated by focusing on the interactions between transport processes and electrochemical parameters. Electrochemistry at the three-phase boundary is modeled by a modified Butler-Volmer approach that considers H2O electrolysis and CO2 electrolysis, individually, as electrochemically active charge transfer pathways. The model is independent of the geometrical structure. A 42-step elementary heterogeneous reaction mechanism for the thermo-catalytic chemistry in the fuel electrode, the dusty gas model (DGM) to account for multi-component diffusion through porous media, and a plug flow model for flow through the channels are used in the model. Two sets of experimental data are reproduced by the simulations, in order to deduce parameters of the electrochemical model. The influence of micro-structural properties, inlet cathode gas velocity, and temperature are discussed. Reaction flow analysis is performed, at OCV, to study methane production characteristics and kinetics during co-electrolysis. Simulations are carried out for configurations ranging from simple one-dimensional electrochemical button cells to quasi-two-dimensional co-flow planar cells, to demonstrate the effectiveness of the computational tool for performance and design optimization.

Recent Developments in Superheated Steam Processing of Foods-A Review.

PubMed

Alfy, Anto; Kiran, B V; Jeevitha, G C; Hebbar, H Umesh

2016-10-02

Although the use of superheated steam has been known for quite a long time, only in the recent past has it emerged as a viable technology for food processing. Superheated steam, having higher enthalpy, can quickly transfer heat to the material being processed, resulting in its rapid heating. The major advantages of using superheated steam for food processing are better product quality (color, shrinkage, and rehydration characteristics), reduced oxidation losses, and higher energy efficiency. This review provides a comprehensive overview of recent studies on the application of superheated steam for food-processing operations such as drying, decontamination and microbial load reduction, parboiling, and enzyme inactivation. The review encompasses aspects such as the effect of superheated steam processing on product quality, mathematical models reported for superheated steam drying, and the future scope of application in food processing. Recent studies on process improvisation, wherein superheated steam is used at low pressure, in fluidized bed mode, sequential processing with hot air/infrared, and in combination with micro droplets of water have also been discussed.

Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

NASA Technical Reports Server (NTRS)

Curreri, Peter A.

2009-01-01

This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and MSFC, and Ohio State University and MIT. Progress in measuring cell efficiency for oxygen production, development of non reacting electrodes, and cell feeding and withdrawal will be discussed.

40 CFR 408.270 - Applicability; description of the steamed and canned oyster processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... steamed and canned oyster processing subcategory. 408.270 Section 408.270 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Steamed and Canned Oyster Processing Subcategory § 408.270 Applicability; description of the steamed and canned oyster processing subcategory. The provisions of this subpart are...

Production of aluminum metal by electrolysis of aluminum sulfide

DOEpatents

Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

1982-04-01

Metallic aluminum may be produced by the electrolysis of Al/sub 2/S/sub 3/ at 700 to 800/sup 0/C in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

Production of aluminum metal by electrolysis of aluminum sulfide

DOEpatents

Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

1984-01-01

Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

Some Aspects of PDC Electrolysis

NASA Astrophysics Data System (ADS)

Poláčik, Ján; Pospíšil, Jiří

2016-10-01

In this paper, aspects of pulsed direct current (PDC) water splitting are described. Electrolysis is a simple and well-known method to produce hydrogen. The efficiency is relatively low in normal conditions using conventional DC. PDC in electrolysis brings about many advantages. It increases efficiency of hydrogen production, and performance of the electrolyser may be smoothly controlled without compromising efficiency of the process. In our approach, ultra-short pulses are applied. This method enhances efficiency of electrical energy in the process of decomposition of water into hydrogen and oxygen. Efficiency depends on frequency, shape and width of the electrical pulses. Experiments proved that efficiency was increased by 2 to 8 per cent. One of the prospects of PDC electrolysis producing hydrogen is in increase of efficiency of energy storage efficiency in the hydrogen. There are strong efforts to make the electrical grid more efficient and balanced in terms of production by installing electricity storage units. Using hydrogen as a fuel decreases air pollution and amount of carbon dioxide emissions in the air. In addition to energy storage, hydrogen is also important in transportation and chemical industry.

Electrochemical processing of solid waste

NASA Technical Reports Server (NTRS)

Bockris, J. OM.; Hitchens, G. D.; Kaba, L.

1988-01-01

The investigation into electrolysis as a means of waste treatment and recycling on manned space missions is described. The electrochemical reactions of an artificial fecal waste mixture was examined. Waste electrolysis experiments were performed in a single compartment reactor, on platinum electrodes, to determine conditions likely to maximize the efficiency of oxidation of fecal waste material to CO2. The maximum current efficiencies for artificial fecal waste electrolysis to CO2 was found to be around 50 percent in the test apparatus. Experiments involving fecal waste oxidation on platinum indicates that electrodes with a higher overvoltage for oxygen evolution such as lead dioxide will give a larger effective potential range for organic oxidation reactions. An electrochemical packed column reactor was constructed with lead dioxide as electrode material. Preliminary experiments were performed using a packed-bed reactor and continuous flow techniques showing this system may be effective in complete oxidation of fecal material. The addition of redox mediator Ce(3+)/Ce(4+) enhances the oxidation process of biomass components. Scientific literature relevant to biomass and fecal waste electrolysis were reviewed.

Electrochemistry of lunar rocks

NASA Technical Reports Server (NTRS)

Lindstrom, D. J.; Haskin, L. A.

1979-01-01

Electrolysis of silicate melts has been shown to be an effective means of producing metals from common silicate materials. No fluxing agents need be added to the melts. From solution in melts of diopside (CaMgSi2O6) composition, the elements Si, Ti, Ni, and Fe have been reduced to their metallic states. Platinum is a satisfactory anode material, but other cathode materials are needed. Electrolysis of compositional analogs of lunar rocks initially produces iron metal at the cathode and oxygen gas at the anode. Utilizing mainly heat and electricity which are readily available from sunlight, direct electrolysis is capable of producing useful metals from common feedstocks without the need for expendable chemicals. This simple process and the products obtained from it deserve further study for use in materials processing in space.

Identification of the states of the processes that occur on solid cathodes in the potentiostatic electrolysis mode using semantic diagram models

NASA Astrophysics Data System (ADS)

Smirnov, G. B.; Markina, S. E.; Tomashevich, V. G.

2011-02-01

A procedure is proposed to construct semantic diagram models for the electrolysis on a solid cathode in a salt halide melt under potentiostatic conditions. These models are intended to identify the static states of the system that correspond to a certain combination of the processes occurring on an electrode and in the system volume. Examples for discharging of univalent and polyvalent metals are given.

Development status of a preprototype water electrolysis subsystem

NASA Technical Reports Server (NTRS)

Martin, R. B.; Erickson, A. C.

1981-01-01

A preprototype water electrolysis subsystem was designed and fabricated for NASA's advanced regenerative life support program. A solid polymer is used for the cell electrolyte. The electrolysis module has 12 cells that can generate 5.5 kg/day of oxygen for the metabolic requirements of three crewmembers, for cabin leakage, and for the oxygen and hydrogen required for carbon dioxide collection and reduction processes. The subsystem can be operated at a pressure between 276 and 2760 kN/sq m and in a continuous constant-current, cyclic, or standby mode. A microprocessor is used to aid in operating the subsystem. Sensors and controls provide fault detection and automatic shutdown. The results of development, demonstration, and parametric testing are presented. Modifications to enhance operation in an integrated and manned test are described. Prospective improvements for the electrolysis subsystem are discussed.

Preparation of aluminum-magnesium alloy from magnesium oxide in RECl3-KCl-MgCl2 electrolyte by molten salts electrolysis method

NASA Astrophysics Data System (ADS)

Yang, Shaohua; Wu, Lin; Yang, Fengli; Li, Mingzhou; Hu, Xianwei; Wang, Zhaowen; Shi, Zhongning; Gao, Bingliang

Aluminum-magnesium alloys were prepared from magnesium oxide by molten salt electrolysis method. 10w%RECl3-63.5w%KCl-23.5w%MgCl2-3w%MgO was taken as electrolyte. The results showed that RE could be attained in aluminum-magnesium alloy, and it was proved that the RE was reduced directly by aluminum. Magnesium in the alloy was produced by electrolysis on cathode. The content of RE in the alloy was about 0.8wt %-1.2wt%, and the content of Mg in the alloy was lwt%˜6wt% with electrolytic times. The highest current efficiency was 81.3% with 0.8A/cm2 current density. The process of electrolysis was controlled together by electrochemical polarization and concentration polarization.

Treatment of mature landfill leachate by internal micro-electrolysis integrated with coagulation: a comparative study on a novel sequencing batch reactor based on zero valent iron.

PubMed

Ying, Diwen; Peng, Juan; Xu, Xinyan; Li, Kan; Wang, Yalin; Jia, Jinping

2012-08-30

A comparative study of treating mature landfill leachate with various treatment processes was conducted to investigate whether the method of combined processes of internal micro-electrolysis (IME) without aeration and IME with full aeration in one reactor was an efficient treatment for mature landfill leachate. A specifically designed novel sequencing batch internal micro-electrolysis reactor (SIME) with the latest automation technology was employed in the experiment. Experimental data showed that combined processes obtained a high COD removal efficiency of 73.7 ± 1.3%, which was 15.2% and 24.8% higher than that of the IME with and without aeration, respectively. The SIME reactor also exhibited a COD removal efficiency of 86.1 ± 3.8% to mature landfill leachate in the continuous operation, which is much higher (p<0.05) than that of conventional treatments of electrolysis (22.8-47.0%), coagulation-sedimentation (18.5-22.2%), and the Fenton process (19.9-40.2%), respectively. The innovative concept behind this excellent performance is a combination effect of reductive and oxidative processes of the IME, and the integration electro-coagulation. Optimal operating parameters, including the initial pH, Fe/C mass ratio, air flow rate, and addition of H(2)O(2), were optimized. All results show that the SIME reactor is a promising and efficient technology in treating mature landfill leachate. Copyright © 2012 Elsevier B.V. All rights reserved.

Direct LiT Electrolysis in a Metallic Fusion Blanket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, Luke

2016-09-30

A process that simplifies the extraction of tritium from molten lithium-based breeding blankets was developed. The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fusion/fission reactors is critical in order to maintain low concentrations. This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Extraction is complicated due to required low tritium concentration limits and because of the high affinity of tritium formore » the blanket. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering hydrogen and deuterium through an electrolysis step at high temperatures.« less

Direct Lit Electrolysis In A Metallic Lithium Fusion Blanket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colon-Mercado, H.; Babineau, D.; Elvington, M.

2015-10-13

A process that simplifies the extraction of tritium from molten lithium based breeding blankets was developed.  The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fission/fusion reactors is critical in order to maintained low concentrations.  This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Because of the high affinity of tritium for the blanket, extraction is complicated at the required low levels. This workmore » identified, developed and tested the use of ceramic lithium ion conductors capable of recovering the hydrogen and deuterium thru an electrolysis step at high temperatures. « less

Reductive dehalogenation of disinfection byproducts by an activated carbon-based electrode system.

PubMed

Li, Yuanqing; Kemper, Jerome M; Datuin, Gwen; Akey, Ann; Mitch, William A; Luthy, Richard G

2016-07-01

Low molecular weight, uncharged, halogenated disinfection byproducts (DBPs) are poorly removed by the reverse osmosis and advanced oxidation process treatment units often applied for further treatment of municipal wastewater for potable reuse. Granular activated carbon (GAC) treatment effectively sorbed 22 halogenated DBPs. Conversion of the GAC to a cathode within an electrolysis cell resulted in significant degradation of the 22 halogenated DBPs by reductive electrolysis at -1 V vs. Standard Hydrogen Electrode (SHE). The lowest removal efficiency over 6 h electrolysis was for trichloromethane (chloroform; 47%) but removal efficiencies were >90% for 13 of the 22 DBPs. In all cases, DBP degradation was higher than in electrolysis-free controls, and degradation was verified by the production of halides as reduction products. Activated carbons and charcoal were more effective than graphite for electrolysis, with graphite featuring poor sorption for the DBPs. A subset of halogenated DBPs (e.g., haloacetonitriles, chloropicrin) were degraded upon sorption to the GAC, even without electrolysis. Using chloropicrin as a model, experiments indicated that this loss was attributable to the partial reduction of sorbed chloropicrin from reducing equivalents in the GAC. Reducing equivalents depleted by these reactions could be restored when the GAC was treated by reductive electrolysis. GAC treatment of an advanced treatment train effluent for potable reuse effectively reduced the concentrations of chloroform, bromodichloromethane and dichloroacetonitrile measured in the column influent to below the method detection limits. Treatment of the GAC by reductive electrolysis at -1 V vs. SHE over 12 h resulted in significant degradation of the chloroform (63%), bromodichloromethane (96%) and dichloroacetonitrile (99%) accumulated on the GAC. The results suggest that DBPs in advanced treatment train effluents could be captured and degraded continuously by reductive electrolysis using a GAC-based cathode. Copyright © 2016 Elsevier Ltd. All rights reserved.

Extraction processes for the production of aluminum, titanium, iron, magnesium, and oxygen and nonterrestrial sources

NASA Technical Reports Server (NTRS)

Rao, D. B.; Choudary, U. V.; Erstfeld, T. E.; Williams, R. J.; Chang, Y. A.

1979-01-01

The suitability of existing terrestrial extractive metallurgical processes for the production of Al, Ti, Fe, Mg, and O2 from nonterrestrial resources is examined from both thermodynamic and kinetic points of view. Carbochlorination of lunar anorthite concentrate in conjunction with Alcoa electrolysis process for Al; carbochlorination of lunar ilmenite concentrate followed by Ca reduction of TiO2; and subsequent reduction of Fe2O3 by H2 for Ti and Fe, respectively, are suggested. Silicothermic reduction of olivine concentrate was found to be attractive for the extraction of Mg becaue of the technological knowhow of the process. Aluminothermic reduction of olivine is the other possible alternative for the production of magnesium. The large quantities of carbon monoxide generated in the metal extraction processes can be used to recover carbon and oxygen by a combination of the following methods: (1) simple disproportionation of CO,(2) methanation of CO and electrolysis of H2O, and (3) solid-state electrolysis of gas mixtures containing CO, CO2, and H2O. The research needed for the adoption of earth-based extraction processes for lunar and asteroidal minerals is outlined.

Production of oxygen from lunar soil by molten salt electrolysis

NASA Technical Reports Server (NTRS)

Keller, Rudolf

1989-01-01

A simple approach to utilizing lunar resources proposes to dissolve lunar soil, without or with little beneficiation, in a suitable molten salt and to electrolyze the oxides to oxygen and a metal byproduct. The envisioned process and the required technological advances are discussed. Promising electrolysis conditions have been identified in a recent experimental program to manufacture silicon and aluminum from anorthite.

Fluid Bed Dehydration of Magnesium Chloride

NASA Astrophysics Data System (ADS)

Adham, K.; Lee, C.; O'Keefe, K.

Molten salt electrolysis of MgCl2 is commonly used for the production of magnesium metal. However, the electrolysis feed must be completely dry with minimum oxygen content. Therefore, complete dehydration of the MgCl2 brine or the hydrated prill is a required process, which is very challenging because of the ease of thermal degradation due to hydrolysis of magnesium chloride.

Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

DOEpatents

Tiernan, Joan E.

1990-01-01

Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and laminar flow conditions at an average detention time of six hours. Both the polyurethane foams and the foam regenerate solution are re-used. The treatment is a cost-effective process for waste-waters which are not treatable, or are not cost-effectively treatable, by conventional process series.

Treatment of coking wastewater by a novel electric assisted micro-electrolysis filter.

PubMed

Xie, Ruosong; Wu, Miaomiao; Qu, Guangfei; Ning, Ping; Cai, Yingying; Lv, Pei

2018-04-01

A newly designed electric assisted micro-electrolysis filter (E-ME) was developed to investigate its degradation efficiency for coking wastewater and correlated characteristics. The performance of the E-ME system was compared with separate electrolysis (SE) and micro-electrolysis (ME) systems. The results showed a prominent synergistic effect on COD removal in E-ME systems. Gas chromatography/mass spectrometry (GC-MS) analysis confirmed that the applied electric field enhanced the degradation of phenolic compounds. Meanwhile, more biodegradable oxygen-bearing compounds were detected. SEM images of granular activated carbon (GAC) showed that inactivation and blocking were inhibited during the E-ME process. The effects of applied voltage and initial pH in E-ME systems were also studied. The best voltage value was 1V, but synergistic effects existed even with lower applied voltage. E-ME systems exhibited some pH buffering capacity and attained the best efficiency in neutral media, which means that there is no need to adjust pH prior to or during the treatment process. Therefore, E-ME systems were confirmed as a promising technology for treatment of coking wastewater and other refractory wastewater. Copyright © 2017. Published by Elsevier B.V.

Treating soil-washing fluids polluted with oxyfluorfen by sono-electrolysis with diamond anodes.

PubMed

Vieira Dos Santos, E; Sáez, C; Cañizares, P; Martínez-Huitle, C A; Rodrigo, M A

2017-01-01

This works is focused on the treatment by sono-electrolysis of the liquid effluents produced during the Surfactant-Aided Soil-Washing (SASW) of soils spiked with herbicide oxyfluorfen. Results show that this combined technology is very efficient and attains the complete mineralization of the waste, regardless of the surfactant/soil radio applied in the SASW process (which is the main parameter of the soil remediation process and leads to very different wastes). Both the surfactant and the herbicide are completely degraded, even when single electrolysis is used; and only two intermediates are detected by HPLC in very low concentrations. Conversely, the efficiency of single sonolysis approach, for the oxidation of pollutant, is very low and just small changes in the herbicides and surfactant concentrations are observed during the tests carried out. Sono-electrolysis with diamond electrodes achieved higher degradation rates than those obtained by single sonolysis and/or single electrolysis with diamond anodes. A key role of sulfate is developed, when it is released after the electrochemical degradation of surfactant. The efficient catalytic effect observed which can be explained by the anodic formation of persulfate and the later, a sono-activation is attained to produce highly efficient sulfate radicals. The effect of irradiating US is more importantly observed in the pesticide than in the surfactant, in agreement with the well-known behavior of these radicals which are known to oxidize more efficiently aromatic compounds than aliphatic species. Copyright © 2016 Elsevier B.V. All rights reserved.

Enhanced degradation of phenolic compounds in coal gasification wastewater by a novel integration of micro-electrolysis with biological reactor (MEBR) under the micro-oxygen condition.

PubMed

Ma, Weiwei; Han, Yuxing; Xu, Chunyan; Han, Hongjun; Ma, Wencheng; Zhu, Hao; Li, Kun; Wang, Dexin

2018-03-01

The aim of this work was to study an integration of micro-electrolysis with biological reactor (MEBR) for strengthening removal of phenolic compounds in coal gasification wastewater (CGW). The results indicated MEBR achieved high efficiencies in removal of COD and phenolic compounds as well as improvement of biodegradability of CGW under the micro-oxygen condition. The integrated MEBR process was more favorable to improvement of the structural stability of activated sludge and biodiversity of specific functional microbial communities. Especially, Shewanella and Pseudomonas were enriched to accelerate the extracellular electron transfer, finally facilitating the degradation of phenolic compounds. Moreover, MEBR process effectively relieved passivation of Fe-C filler surface and prolonged lifespan of Fe-C filler. Accordingly, the synergetic effect between iron-carbon micro-electrolysis (ICME) and biological action played a significant role in performance of the integrated process. Therefore, the integrated MEBR was a promising practical process for enhancing CGW treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of anhydrous aluminum chloride composition and process for electrolysis thereof

DOEpatents

Vandegrift, George F.; Krumpelt, Michael; Horwitz, E. Philip

1983-01-01

A process for producing an anhydrous aluminum chloride composition from a water-based aluminous material such as a slurry of aluminum hydroxide in a multistage extraction process in which the aluminum ion is first extracted into an organic liquid containing an acidic extractant and then extracted from the organic phase into an alkali metal chloride or chlorides to form a melt containing a mixture of chlorides of alkali metal and aluminum. In the process, the organic liquid may be recycled. In addition, the process advantageously includes an electrolysis cell for producing metallic aluminum and the alkali metal chloride or chlorides may be recycled for extraction of the aluminum from the organic phase.

Vehicle Integrated Photovoltaics for Compression Ignition Vehicles: An Experimental Investigation of Solar Alkaline Water Electrolysis for Improving Diesel Combustion and a Solar Charging System for Reducing Auxiliary Engine Loads

NASA Astrophysics Data System (ADS)

Negroni, Garry Inocentes

Vehicle-integrated photovoltaic electricity can be applied towards aspiration of hydrogen-oxygen-steam gas produced through alkaline electrolysis and reductions in auxiliary alternator load for reducing hydrocarbon emissions in low nitrogen oxide indirect-injection compression-ignition engines. Aspiration of 0.516 ± 0.007 liters-per-minute of gas produced through alkaline electrolysis of potassium-hydroxide 2wt.% improves full-load performance; however, part-load performance decreases due to auto-ignition of aspirated gas prior to top-dead center. Alternator load reductions offer improved part-load and full-load performance with practical limitations resulting from accessory electrical loads. In an additive approach, solar electrolysis can electrochemically convert solar photovoltaic electricity into a gas comprised of stoichiometric hydrogen and oxygen gas. Aspiration of this hydrogen-oxygen gas enhances combustion properties decreasing emissions and increased combustion efficiency in light-duty diesel vehicles. The 316L stainless steel (SS) electrolyser plates are arranged with two anodes and three cathodes space with four bipolar plates delineating four stacks in parallel with five cells per stack. The electrolyser was tested using potassium hydroxide 2 wt.% and hydronium 3wt.% at measured voltage and current inputs. The flow rate output from the reservoir cell was measured in parallel with the V and I inputs producing a regression model correlating current input to flow rate. KOH 2 wt.% produced 0.005 LPM/W, while H9O44 3 wt.% produced less at 0.00126 LPM/W. In a subtractive approach, solar energy can be used to charge a larger energy storage device, as is with plug-in electric vehicles, in order to alleviate the engine of the mechanical load placed upon it by the vehicles electrical accessories through the alternator. Solar electrolysis can improve part-load emissions and full-load performance. The average solar-to-battery efficiency based on the OEM rated efficiency was 11.4%. The average voltage efficiency of the electrolyser during dynamometer testing was 69.16%, producing a solar-to-electrolysis efficiency of 7.88%. At varying engine speeds, HC emissions decreased an average of 54.4% at multiple engine speeds at part-load, while CO2 increased by 2.54% due to oxygen enrichment of intake air. However, the auto-ignition of a small amount of hydrogen (0.0035% of diesel fuel energy) had a negative impact on part-load power (-3.671%) and torque (-3.296%). Full-load sweep testing showed an increase in peak power (1.562%) and peak torque (2.608%). Solar electrolysis gas aspiration reduced soot opacity by 31.5%. The alternator-less part-load step tests show average HC and CO2 emissions decrease on average 25.05% and 1.14% respectively. The test also indicates an increase in average part-load power (1.57%) and torque (2.12%). Alternator-less operation can reduce soot opacity by 56.76%. Full-load testing of the vehicle with alternator unplugged indicates that alternator load upon an engine increase with engine ne speed even with no load and no pilot excitation. Alternator load elimination's performance and emissions improvements should be considered, however, practical limitations exist in winter-night, summer-midday scenarios and for longer duration of operation.

CeO2-Y2O3-ZrO2 Membrane with Enhanced Molten Salt Corrosion Resistance for Solid Oxide Membrane (SOM) Electrolysis Process

NASA Astrophysics Data System (ADS)

Zou, Xingli; Li, Xin; Shen, Bin; Lu, Xionggang; Xu, Qian; Zhou, Zhongfu; Ding, Weizhong

2017-02-01

Innovative CeO2-Y2O3-ZrO2 membrane has been successfully developed and used in the solid oxide membrane (SOM) electrolysis process for green metallic materials production. The x mol pct ceria/(8- x) mol pct yttria-costabilized zirconia ( xCe(8- x)YSZ, x = 0, 1, 4, or 7) membranes have been fabricated and investigated as the membrane-based inert anodes to control the SOM electroreduction process in molten salt. The characteristics of these fabricated xCe(8- x)YSZ membranes including their corrosion resistances in molten salt and their degradation mechanisms have been systematically investigated and compared. The results show that the addition of ceria in the YSZ-based membrane can inhibit the depletion of yttrium during the SOM electrolysis, which thus makes the ceria-reinforced YSZ-based membranes possess enhanced corrosion resistances to molten salt. The ceria/yttria-costabilized zirconia membranes can also provide reasonable oxygen ion conductivity during electrolysis. Further investigation shows that the newly modified 4Ce4YSZ ceramic membrane has the potential to be used as novel inert SOM anode for the facile and sustainable production of metals/alloys/composites materials such as Si, Ti5Si3, TiC, and Ti5Si3/TiC from their metal oxides precursors in molten CaCl2.

Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saksono, Nelson; Febiyanti, Irine Ayu, E-mail: irine.ayu41@ui.ac.id; Utami, Nissa

2015-12-29

Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H{sub 2}O{sub 2} amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical currentmore » throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.« less

Electrolysis of a molten semiconductor

PubMed Central

Yin, Huayi; Chung, Brice; Sadoway, Donald R.

2016-01-01

Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

Electrolysis of a molten semiconductor.

PubMed

Yin, Huayi; Chung, Brice; Sadoway, Donald R

2016-08-24

Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

Electrolysis of a molten semiconductor

NASA Astrophysics Data System (ADS)

Yin, Huayi; Chung, Brice; Sadoway, Donald R.

2016-08-01

Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

Degradation mechanism of Direct Pink 12B treated by iron-carbon micro-electrolysis and Fenton reaction.

PubMed

Wang, Xiquan; Gong, Xiaokang; Zhang, Qiuxia; Du, Haijuan

2013-12-01

The Direct Pink 12B dye was treated by iron-carbon micro-electrolysis (ICME) and Fenton oxidation. The degradation pathway of Direct Pink 12B dye was inferred by ultraviolet visible (UV-Vis), infrared absorption spectrum (IR) and high performance liquid chromatography-mass spectrometry (HPLC-MS). The major reason of decolorization was that the conjugate structure was disrupted in the iron-carbon micro-electrolysis (ICME) process. However, the dye was not degraded completely because benzene rings and naphthalene rings were not broken. In the Fenton oxidation process, the azo bond groups surrounded by higher electron cloud density were first attacked by hydroxyl radicals to decolorize the dye molecule. Finally benzene rings and naphthalene rings were mineralized to H2O and CO2 under the oxidation of hydroxyl radicals. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Influences of operational parameters on phosphorus removal in batch and continuous electrocoagulation process performance.

PubMed

Nguyen, Dinh Duc; Yoon, Yong Soo; Bui, Xuan Thanh; Kim, Sung Su; Chang, Soon Woong; Guo, Wenshan; Ngo, Huu Hao

2017-11-01

Performance of an electrocoagulation (EC) process in batch and continuous operating modes was thoroughly investigated and evaluated for enhancing wastewater phosphorus removal under various operating conditions, individually or combined with initial phosphorus concentration, wastewater conductivity, current density, and electrolysis times. The results revealed excellent phosphorus removal (72.7-100%) for both processes within 3-6 min of electrolysis, with relatively low energy requirements, i.e., less than 0.5 kWh/m 3 for treated wastewater. However, the removal efficiency of phosphorus in the continuous EC operation mode was better than that in batch mode within the scope of the study. Additionally, the rate and efficiency of phosphorus removal strongly depended on operational parameters, including wastewater conductivity, initial phosphorus concentration, current density, and electrolysis time. Based on experimental data, statistical model verification of the response surface methodology (RSM) (multiple factor optimization) was also established to provide further insights and accurately describe the interactive relationship between the process variables, thus optimizing the EC process performance. The EC process using iron electrodes is promising for improving wastewater phosphorus removal efficiency, and RSM can be a sustainable tool for predicting the performance of the EC process and explaining the influence of the process variables.

Direct Electrochemical Preparation of Cobalt, Tungsten, and Tungsten Carbide from Cemented Carbide Scrap

NASA Astrophysics Data System (ADS)

Xiao, Xiangjun; Xi, Xiaoli; Nie, Zuoren; Zhang, Liwen; Ma, Liwen

2017-02-01

A novel process of preparing cobalt, tungsten, and tungsten carbide powders from cemented carbide scrap by molten salt electrolysis has been investigated in this paper. In this experiment, WC-6Co and NaCl-KCl salt were used as sacrificial anode and electrolyte, respectively. The dissolution potential of cobalt and WC was determined by linear sweep voltammetry to be 0 and 0.6 V ( vs Ag/AgCl), respectively. Furthermore, the electrochemical behavior of cobalt and tungsten ions was investigated by a variety of electrochemical techniques. Results of cyclic voltammetry (CV) and square-wave voltammetry show that the cobalt and tungsten ions existed as Co2+ and W2+ on melts, respectively. The effect of applied voltage, electrolysis current, and electrolysis times on the composition of the product was studied. Results showed that pure cobalt powder can be obtained when the electrolysis potential is lower than 0.6 V or during low current and short times. Double-cathode and two-stage electrolysis was utilized for the preparation of cobalt, tungsten carbide, and tungsten powders. Additionally, X-ray diffraction results confirm that the product collected at cathodes 1 and 2 is pure Co and WC, respectively. Pure tungsten powder was obtained after electrolysis of the second part. Scanning electron microscope results show that the diameters of tungsten, tungsten carbide, and cobalt powder are smaller than 100, 200, and 200 nm, respectively.

Gadolinia-Doped Ceria Cathodes for Electrolysis of CO2

NASA Technical Reports Server (NTRS)

Adler, Stuart B.

2009-01-01

Gadolinia-doped ceria, or GDC, (Gd(0.4)Ce(0.6)O(2-delta), where the value of delta in this material varies, depending on the temperature and oxygen concentration in the atmosphere in which it is being used) has shown promise as a cathode material for high-temperature electrolysis of carbon dioxide in solid oxide electrolysis cells. The polarization resistance of a GDC electrode is significantly less than that of an otherwise equivalent electrode made of any of several other materials that are now in use or under consideration for use as cathodes for reduction of carbon dioxide. In addition, GDC shows no sign of deterioration under typical temperature and gas-mixture operating conditions of a high-temperature electrolyzer. Electrolysis of CO2 is of interest to NASA as a way of generating O2 from the CO2 in the Martian atmosphere. On Earth, a combination of electrolysis of CO2 and electrolysis of H2O might prove useful as a means of generating synthesis gas (syngas) from the exhaust gas of a coal- or natural-gas-fired power plant, thereby reducing the emission of CO2 into the atmosphere. The syngas a mixture of CO and H2 could be used as a raw material in the manufacture, via the Fisher-Tropsch process, of synthetic fuels, lubrication oils, and other hydrocarbon prod

Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

PubMed Central

Lugnani, Franco; Macchioro, Matteo

2017-01-01

Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Conclusion Electrolysis can occur in a frozen domain at high subfreezing temperature, probably above the eutectic. It appears that the most effective period for delivering electrolytic currents in cryoelectrolysis is during the high subzero temperatures stage while freezing and immediately after cooling has stopped, throughout the thawing stage. PMID:28123904

Cryoelectrolysis-electrolytic processes in a frozen physiological saline medium.

PubMed

Lugnani, Franco; Macchioro, Matteo; Rubinsky, Boris

2017-01-01

Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Electrolysis can occur in a frozen domain at high subfreezing temperature, probably above the eutectic. It appears that the most effective period for delivering electrolytic currents in cryoelectrolysis is during the high subzero temperatures stage while freezing and immediately after cooling has stopped, throughout the thawing stage.

Application of electrolysis for inactivation of an antiviral drug that is one of possible selection pressure to drug-resistant influenza viruses.

PubMed

Kobayashi, Toyohide; Hirose, Jun; Wu, Hong; Sano, Kouichi; Katsumata, Takahiro; Tsujibo, Hiroshi; Nakano, Takashi

2013-12-01

The recent development of antiviral drugs has led to concern that the release of the chemicals in surface water due to expanded medical use could induce drug-resistant mutant viruses in zoonosis. Many researchers have noted that the appearance of an oseltamivir (Tamiflu(®))-resistant avian influenza mutant virus, which may spread to humans, could be induced by oseltamivir contamination of surface water. Although past studies have reported electrolysis as a possible method for degradation of antineoplastics and antibacterials in water, the validity of the method for treatment of antiviral drugs is unknown. In this study, electrolysis was used to degrade an antiviral prodrug, oseltamivir, and a stable active form, oseltamivir carboxylate, and the degradation process was monitored with HPLC-UV and the neuraminidase inhibitory assay. HPLC-UV-detectable oseltamivir and oseltamivir carboxylate were decomposed by electrolysis within 60 min, and inhibitory activity of neuraminidase decreased below the detection limit of the assay used. Cytotoxic and genotoxic activity were not detected in electrolyzed fluid. These results indicate that electrolysis is a possible treatment for inactivation of the antiviral drug oseltamivir. Copyright © 2013 Elsevier B.V. All rights reserved.

Three-Man Solid Electrolyte Carbon Dioxide Electrolysis Breadboard

NASA Technical Reports Server (NTRS)

Isenberg, Arnold O.

1989-01-01

The development of the Three-Man (2.2 lb CO2/man-day) Solid Electrolyte CO2 Electrolysis Breadboard consisted of a Phase 1 and 2 effort. The Phase 1 effort constituted fabrication of three electrolysis cell types and performing parametric testing, off-design testing, and cell life testing. The Phase 2 consisted of the preliminary design, incorporation of palladium (Pd) tubes for hydrogen separation from the electrolyzer cathode feed gases, design support testing, final design, fabrication, and performance testing of the breadboard system. The results of performance tests demonstrated that CO2 electrolysis in an oxygen reclamation system for long duration space-based habitats is feasible. Closure of the oxygen system loop, therefore, can be achieved by CO2 electrolysis. In a two step process the metabolic CO2 and H2O vapor are electrolyzed into O2, H2, and CO. The CO can subsequently be disproportionated into carbon and CO2 in a carbon deposition reactor and the CO2 in turn be recycled and electrolyzed for total O2 recovery. The development effort demonstrated electrolyzer system can be designed and built to operate safely and reliably and the incorporation of Pd tubes for hydrogen diffusion can be integrated safely with predictable performance.

Improved enzymatic hydrolysis of lignocellulosic biomass through pretreatment with plasma electrolysis.

PubMed

Gao, Jing; Chen, Li; Zhang, Jian; Yan, Zongcheng

2014-11-01

A comprehensive research on plasma electrolysis as pretreatment method for water hyacinth (WH) was performed based on lignin content, crystalline structure, surface property, and enzymatic hydrolysis. A large number of active particles, such as HO and H2O2, generated by plasma electrolysis could decompose the lignin of the biomass samples and reduce the crystalline index. An efficient pretreatment process made use of WH pretreated at a load of 48 wt% (0.15-0.18 mm) in FeCl3 solution for 30 min at 450 V. After the pretreatment, the sugar yield of WH was increased by 126.5% as compared with unpretreated samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Complex technology for water and wastewater disinfection and its industrial realization in prototype unit].

PubMed

Arakcheev, E N; Brunman, V E; Brunman, M V; Konyashin, A V; Dyachenko, V A; Petkova, A P

Usage of complex automated electrolysis unit for drinking water disinfection and wastewater oxidation and coagulation is scoped, its ecological and energy efficiency is shown. Properties of technological process of anolyte production using membrane electrolysis of brine for water disinfection in municipal pipelines and potassium ferrate production using electrochemical dissolution of iron anode in NaOH solution for usage in purification plants are listed. Construction of modules of industrial prototype for anolyte and ferrate production and applied aspects of automation of complex electrolysis unit are proved. Results of approbation of electrolytic potassium ferrate for drinking water disinfection and wastewater, rain water and environmental water oxidation and coagulation are shown.

From Oxygen Generation to Metals Production: In Situ Resource Utilization by Molten Oxide Electrolysis

NASA Technical Reports Server (NTRS)

Khetpal, Deepak; Ducret, Andrew C.; Sadoway, Donald R.

2003-01-01

For the exploration of other bodies in the solar system, electrochemical processing is arguably the most versatile technology for conversion of local resources into usable commodities: by electrolysis one can, in principle, produce (1) breathable oxygen, (2) silicon for the fabrication of solar cells, (3) various reactive metals for use as electrodes in advanced storage batteries, and (4) structural metals such as steel and aluminum. Even so, to date there has been no sustained effort to develop such processes, in part due to the inadequacy of the database. The objective here is to identify chemistries capable of sustaining molten oxide electrolysis in the cited applications and to examine the behavior of laboratory-scale cells designed to generate oxygen and to produce metal. The basic research includes the study of the underlying high-temperature physical chemistry of oxide melts representative of lunar regolith and of Martian soil. To move beyond empirical approaches to process development, the thermodynamic and transport properties of oxide melts are being studied to help set the limits of composition and temperature for the processing trials conducted in laboratory-scale electrolysis cells. The goal of this investigation is to deliver a working prototype cell that can use lunar regolith and Martian soil to produce breathable oxygen along with metal by-product. Additionally, the process can be generalized to permit adaptation to accommodate different feedstock chemistries, such as those that will be encountered on other bodies in the solar system. The expected results of this research include: (1) the identification of appropriate electrolyte chemistries; (2) the selection of candidate anode and cathode materials compatible with electrolytes named above; and (3) performance data from a laboratory-scale cell producing oxygen and metal. On the strength of these results it should be possible to assess the technical viability of molten oxide electrolysis for in situ resource utilization on the Moon and Mars. In parallel, there may be commercial applications here on earth, such as new green technologies for metals extraction and for treatment of hazardous waste, e.g., fixing heavy metals.

Water Electrolysis for In-Situ Resource Utilization (ISRU)

NASA Technical Reports Server (NTRS)

Lee, Kristopher A.

2016-01-01

Sending humans to Mars for any significant amount of time will require capabilities and technologies that enable Earth independence. To move towards this independence, the resources found on Mars must be utilized to produce the items needed to sustain humans away from Earth. To accomplish this task, NASA is studying In Situ Resource Utilization (ISRU) systems and techniques to make use of the atmospheric carbon dioxide and the water found on Mars. Among other things, these substances can be harvested and processed to make oxygen and methane. Oxygen is essential, not only for sustaining the lives of the crew on Mars, but also as the oxidizer for an oxygen-methane propulsion system that could be utilized on a Mars ascent vehicle. Given the presence of water on Mars, the electrolysis of water is a common technique to produce the desired oxygen. Towards this goal, NASA designed and developed a Proton Exchange Membrane (PEM) water electrolysis system, which was originally slated to produce oxygen for propulsion and fuel cell use in the Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project. As part of the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) project, this same electrolysis system, originally targeted at enabling in situ propulsion and power, operated in a life-support scenario. During HESTIA testing at Johnson Space Center, the electrolysis system supplied oxygen to a chamber simulating a habitat housing four crewmembers. Inside the chamber, oxygen was removed from the atmosphere to simulate consumption by the crew, and the electrolysis system's oxygen was added to replenish it. The electrolysis system operated nominally throughout the duration of the HESTIA test campaign, and the oxygen levels in the life support chamber were maintained at the desired levels.

Carbon dioxide electrolysis using a ceramic electrolyte. [for space processing

NASA Technical Reports Server (NTRS)

Erstfeld, T. E.; Mullins, O., Jr.; Williams, R. J.

1979-01-01

This paper discusses the results of an experimental study of the electrical aspects of carbon dioxide electrolysis using a ceramic electrolyte. The electrolyte compositions used in this study are 8% Y2O3 stabilized ZrO2, 7.5% CaO stabilized ZrO2, and 5% Y2O3 stabilized ThO2. Results indicate that the 8% Y2O3 stabilized ZrO2 is the best material to use for electrolysis, in terms of current as a function of voltage and temperature, and in terms of efficiency of oxide ion flow through it. The poorest results were obtained with the 5% Y2O3 stabilized ThO2 composition. An electrolysis system which might be employed to reclaim oxygen and carbon from effluents of space manufacturing, assuming that an industry would have to electrolyze 258,000 tonnes of CO2 per year, is predicted to require a total cell area of 110,000 sq m of 1 mm thickness and electrical capacity of 441 MW.

Formation of Intermetallic Phases in Al-Sc Alloys Prepared by Molten Salt Electrolysis at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Wang, Zengjie; Guan, Chunyang; Liu, Qiaochu; Xue, Jilai

Molten salts electrolysis method to prepare Al-RE alloys has attracted increasing attention recently. CaCl2 and Na3AlF6 were the most often used melts for this purpose. In this work, Al-Sc alloys prepared by electrolytic deposition process in both CaCl2 and Na3AlF6 melts were investigated, respectively. It was found that Sc distributes almost uniformly and Sc contents increase with increasing current intensity in both melts. Current efficiency was measured for comparison among various current densities applied. The alloy products were analyzed using XRD and SEM, where the formation behaviors of Al-Sc intermetallics were investigated in details. The experimental and theoretical results demonstrate that Al3Sc and Al0.968Sc0.032 are the major precipitates in the Al-Sc alloys prepared by molten electrolysis. The results are useful for selection and optimization of the molten salts compositions and the parameters of electrolysis operation.

Membrane water-flow rate in electrolyzer cells with a solid polymer electrolyte (SPE)

NASA Astrophysics Data System (ADS)

Li, Xiaojin; Qu, Shuguo; Yu, Hongmei; Hou, Ming; Shao, Zhigang; Yi, Baolian

Water-flow rate across Nafion membrane in SPE electrolyzer cells was measured and modelled. From the analysis of water transport mechanisms in SPE water electrolysis, the water-flow rate through membrane can be described by the electro-osmotic drag. The calculated electro-osmotic drag coefficients, n d, for the membrane in SPE electrolysis cells at different temperatures were compared with literature and in good agreement with those of Ge et al. and Ise et al. To describe the water-flow rate through membrane more accurately, a linear fit of n d as a function of temperature for the membrane in SPE water electrolysis was proposed in this paper. This paper studied the membrane water-flow rate experimentally and mathematically, which is of importance in the designing and optimization of the process of SPE water electrolysis. This paper also provided a novel method for measuring the electro-osmotic drag coefficient of Nafion membrane in contact with liquid water, acid and methanol solutions, etc.

Recent Progress in Energy-Driven Water Splitting.

PubMed

Tee, Si Yin; Win, Khin Yin; Teo, Wee Siang; Koh, Leng-Duei; Liu, Shuhua; Teng, Choon Peng; Han, Ming-Yong

2017-05-01

Hydrogen is readily obtained from renewable and non-renewable resources via water splitting by using thermal, electrical, photonic and biochemical energy. The major hydrogen production is generated from thermal energy through steam reforming/gasification of fossil fuel. As the commonly used non-renewable resources will be depleted in the long run, there is great demand to utilize renewable energy resources for hydrogen production. Most of the renewable resources may be used to produce electricity for driving water splitting while challenges remain to improve cost-effectiveness. As the most abundant energy resource, the direct conversion of solar energy to hydrogen is considered the most sustainable energy production method without causing pollutions to the environment. In overall, this review briefly summarizes thermolytic, electrolytic, photolytic and biolytic water splitting. It highlights photonic and electrical driven water splitting together with photovoltaic-integrated solar-driven water electrolysis.

Recent Progress in Energy‐Driven Water Splitting

PubMed Central

Tee, Si Yin; Win, Khin Yin; Teo, Wee Siang; Koh, Leng‐Duei; Liu, Shuhua; Teng, Choon Peng

2017-01-01

Hydrogen is readily obtained from renewable and non‐renewable resources via water splitting by using thermal, electrical, photonic and biochemical energy. The major hydrogen production is generated from thermal energy through steam reforming/gasification of fossil fuel. As the commonly used non‐renewable resources will be depleted in the long run, there is great demand to utilize renewable energy resources for hydrogen production. Most of the renewable resources may be used to produce electricity for driving water splitting while challenges remain to improve cost‐effectiveness. As the most abundant energy resource, the direct conversion of solar energy to hydrogen is considered the most sustainable energy production method without causing pollutions to the environment. In overall, this review briefly summarizes thermolytic, electrolytic, photolytic and biolytic water splitting. It highlights photonic and electrical driven water splitting together with photovoltaic‐integrated solar‐driven water electrolysis. PMID:28546906

An numerical analysis of high-temperature helium reactor power plant for co-production of hydrogen and electricity

NASA Astrophysics Data System (ADS)

Dudek, M.; Podsadna, J.; Jaszczur, M.

2016-09-01

In the present work, the feasibility of using a high temperature gas cooled nuclear reactor (HTR) for electricity generation and hydrogen production are analysed. The HTR is combined with a steam and a gas turbine, as well as with the system for heat delivery for medium temperature hydrogen production. Industrial-scale hydrogen production using copper-chlorine (Cu-Cl) thermochemical cycle is considered and compared with high temperature electrolysis. Presented cycle shows a very promising route for continuous, efficient, large-scale and environmentally benign hydrogen production without CO2 emissions. The results show that the integration of a high temperature helium reactor, with a combined cycle for electric power generation and hydrogen production, may reach very high efficiency and could possibly lead to a significant decrease of hydrogen production costs.

An electrolytic process for ultra fine beryllium

NASA Technical Reports Server (NTRS)

Lidman, W. G.; Griffiths, V.

1972-01-01

Studies were made on the electrolysis of a molten BeCl2-NaCl bath using a mercury cathode and beryllium anode. A quasi-amalgam was obtained. The beryllium was consolidated by direct hot pressing of the amalgam at temperatures in the range of 800 C and using pressures of 5,000, 10,000 and 20,000 psi. The work confirms the ability to produce ultrafine beryllium particles by electrolysis.

REGENERATION OF REACTOR FUEL ELEMENTS

DOEpatents

Roake, W.E.; Lyon, W.L.

1960-03-29

A process of concentrating by electrolysis the uraatum and/or plutonium of an aluminum alloy containing these actinides after the actinide has been partially consumed by neutron bombardment in a reactor is given. The alloy is made the anode in a system having an aluminum cathode and a cryolite electrolyte. Electrolysis from 22 to 28 ampere-hours removes a sufficient quantity of aluminum from the alloy to make it suitable for reuse.

Simulator of Non-homogenous Alumina and Current Distribution in an Aluminum Electrolysis Cell to Predict Low-Voltage Anode Effects

NASA Astrophysics Data System (ADS)

Dion, Lukas; Kiss, László I.; Poncsák, Sándor; Lagacé, Charles-Luc

2018-04-01

Perfluorocarbons are important contributors to aluminum production greenhouse gas inventories. Tetrafluoromethane and hexafluoroethane are produced in the electrolysis process when a harmful event called anode effect occurs in the cell. This incident is strongly related to the lack of alumina and the current distribution in the cell and can be classified into two categories: high-voltage and low-voltage anode effects. The latter is hard to detect during the normal electrolysis process and, therefore, new tools are necessary to predict this event and minimize its occurrence. This paper discusses a new approach to model the alumina distribution behavior in an electrolysis cell by dividing the electrolytic bath into non-homogenous concentration zones using discrete elements. The different mechanisms related to the alumina distribution are discussed in detail. Moreover, with a detailed electrical model, it is possible to calculate the current distribution among the different anodic assemblies. With this information, the model can evaluate if low-voltage emissions are likely to be present under the simulated conditions. Using the simulator will help the understanding of the role of the alumina distribution which, in turn, will improve the cell energy consumption and stability while reducing the occurrence of high- and low-voltage anode effects.

[Effects of steaming and baking on content of alkaloids in Aconite Lateralis Radix (Fuzi)].

PubMed

Yang, Chang-lin; Huang, Zhi-fang; Zhang, Yi-han; Liu, Yu-hong; Liu, Yun-huan; Chen, Yan; Yi, Jin-hai

2014-12-01

To study the effect of steaming and baking process on contents of alkaloids in Aconite Lateralis Radix (Fuzi), 13 alkaloids were analyzed by UPLC-MS/MS equipped with ESI ion source in MRM mode. In steaming process, the contents of diester-diterpenoid alkaloids decreased rapidly, the contents of monoester-diterpenoid alkaloids firstly increased, reached the peak at 40 min, and then deceased gradually. The contents of aconine alkaloids (mesaconine, aconine and hypaconine) increased all the time during processing, while the contents of fuziline, songorine, karacoline, salsolionl were stable or slightly decreased. In baking process, dynamic variations of alkaloids were different from that in the steaming process. Diester-diterpenoid alkaloids were degraded slightly slower than in steaming process. Monoester-diterpenoid alkaloids, aconine alkaloids and the total alkaloids had been destroyed at different degrees, their contents were significantly lower than the ones in steaming Fuzi at the same processing time. This experiment revealed the dynamic variations of alkaloids in the course of steaming and baking. Two processing methods which can both effectively remove the toxic ingredients and retain the active ingredients are simple and controllable, and are valuable for popularization and application.

Azo dyes wastewater treatment and simultaneous electricity generation in a novel process of electrolysis cell combined with microbial fuel cell.

PubMed

Zou, Haiming; Wang, Yan

2017-07-01

A new process of electrolysis cell (EC) coupled with microbial fuel cell (MFC) was developed here and its feasibility in methyl red (MR) wastewater treatment and simultaneous electricity generation was assessed. Results indicate that an excellent MR removal and electricity production performance was achieved, where the decolorization and COD removal efficiencies were 100% and 89.3%, respectively and a 0.56V of cell voltage output was generated. Electrolysis voltage showed a positive influence on decolorization rate (DR) but also cause a rapid decrease in current efficiency (CE). Although a low COD removal rate of 38.5% was found in EC system, biodegradability of MR solution was significantly enhanced, where the averaged DR was 85.6%. Importantly, COD removal rate in EC-MFC integrated process had a 50.8% improvement compared with the single EC system. The results obtained here would be beneficial to provide a prospective alternative for azo dyes wastewater treatment and power production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of flow velocity on the process of air-steam condensation in a vertical tube condenser

NASA Astrophysics Data System (ADS)

Havlík, Jan; Dlouhý, Tomáš

2018-06-01

This article describes the influence of flow velocity on the condensation process in a vertical tube. For the case of condensation in a vertical tube condenser, both the pure steam condensation process and the air-steam mixture condensation process were theoretically and experimentally analyzed. The influence of steam flow velocity on the value of the heat transfer coefficient during the condensation process was evaluated. For the condensation of pure steam, the influence of flow velocity on the value of the heat transfer coefficient begins to be seen at higher speeds, conversely, this effect is negligible at low values of steam velocity. On the other hand, for the air-steam mixture condensation, the influence of flow velocity must always be taken into account. The flow velocity affects the water vapor diffusion process through non-condensing air. The presence of air significantly reduces the value of the heat transfer coefficient. This drop in the heat transfer coefficient is significant at low velocities; on the contrary, the decrease is relatively small at high values of the velocity.

Trade Study of Five In-Situ Propellant Production System for a Mars Sample Return Mission

NASA Technical Reports Server (NTRS)

Green, S. T.; Deffenbaugh, D. M.; Miller, M. A.

1999-01-01

One of the goals of NASA''s HEDS enterprise is to establish a long-term human presence on Mars at a fraction of the cost of employing today''s technology. The most direct method of reducing mission cost is to reduce the launch mass of the spacecraft. If the propellants for the return phase of the mission are produced on Mars, the total spacecraft mass could be reduced significantly. An interim goal is a Mars Sample Return (MSR) mission, which is proposed to demonstrate the feasibility of in-situ propellant production (ISPP). Five candidate ISPP systems for producing two fuels and oxygen from the Martian atmosphere are considered in this design trade-off study:(1) Zirconia cell with methanol synthesis, (2) Reverse water gas shift (RWGS) with water electrolysis and methanol synthesis, (3) Sabatier process for methane production with water electrolysis, (4) Sabatier process with water electrolysis and partial methane pyrolysis, and (5) Sabatier/RWGS combination with water electrolysis. These systems have been the subject of numerous previous analytical studies and laboratory demonstrations. In this investigation, the systems are objectively compared on the basis of thermochemical performance models using a commonly used chemical plant analysis software package. The realistic effects of incomplete chemical conversion and gas phase separator performance are included in these models. This study focuses on the chemical processing and product separation subsystems. The CO2 compression upstream of the chemical plane and the liquefaction/storage components are not included here.

Breckinridge Project, initial effort

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1982-01-01

The project cogeneration plant supplies electric power, process steam and treated boiler feedwater for use by the project plants. The plant consists of multiple turbine generators and steam generators connected to a common main steam header. The major plant systems which are required to produce steam, electrical power and treated feedwater are discussed individually. The systems are: steam, steam generator, steam generator fuel, condensate and feedwater deaeration, condensate and blowdown collection, cooling water, boiler feedwater treatment, coal handling, ash handling (fly ash and bottom ash), electrical, and control system. The plant description is based on the Phase Zero design basismore » established for Plant 31 in July of 1980 and the steam/condensate balance as presented on Drawing 31-E-B-1. Updating of steam requirements as more refined process information becomes available has generated some changes in the steam balance. Boiler operation with these updated requirements is reflected on Drawing 31-D-B-1A. The major impact of updating has been that less 600 psig steam generated within the process units requires more extraction steam from the turbine generators to close the 600 psig steam balance. Since the 900 psig steam generation from the boilers was fixed at 1,200,000 lb/hr, the additional extraction steam required to close the 600 psig steam balance decreased the quantity of electrical power available from the turbine generators. In the next phase of engineering work, the production of 600 psig steam will be augmented by increasing convection bank steam generation in the Plant 3 fired heaters by 140,000 to 150,000 lb/hr. This modification will allow full rated power generation from the turbine generators.« less

Biodegradability and toxicity assessment of a real textile wastewater effluent treated by an optimized electrocoagulation process.

PubMed

Manenti, Diego R; Módenes, Aparecido N; Soares, Petrick A; Boaventura, Rui A R; Palácio, Soraya M; Borba, Fernando H; Espinoza-Quiñones, Fernando R; Bergamasco, Rosângela; Vilar, Vítor J P

2015-01-01

In this work, the application of an iron electrode-based electrocoagulation (EC) process on the treatment of a real textile wastewater (RTW) was investigated. In order to perform an efficient integration of the EC process with a biological oxidation one, an enhancement in the biodegradability and low toxicity of final compounds was sought. Optimal values of EC reactor operation parameters (pH, current density and electrolysis time) were achieved by applying a full factorial 3(3) experimental design. Biodegradability and toxicity assays were performed on treated RTW samples obtained at the optimal values of: pH of the solution (7.0), current density (142.9 A m(-2)) and different electrolysis times. As response variables for the biodegradability and toxicity assessment, the Zahn-Wellens test (Dt), the ratio values of dissolved organic carbon (DOC) relative to low-molecular-weight carboxylates anions (LMCA) and lethal concentration 50 (LC50) were used. According to the Dt, the DOC/LMCA ratio and LC50, an electrolysis time of 15 min along with the optimal values of pH and current density were suggested as suitable for a next stage of treatment based on a biological oxidation process.

Evaluation Of In Situ Steam-Injection Processes For Reduction Of Petroleum Compounds Within An Abandoned Canal

EPA Science Inventory

A conceptual approach of a novel application of in-situ thermal processes that would either use a steam injection process or a steam/surfactant injection process was considered to remediate petroleum contaminated sediment residing in an abandoned canal. Laboratory tests were c...

Steam distillation extraction of ginger essential oil: Study of the effect of steam flow rate and time process

NASA Astrophysics Data System (ADS)

Fitriady, Muhammad Arifuddin; Sulaswatty, Anny; Agustian, Egi; Salahuddin, Aditama, Deska Prayoga Fauzi

2017-01-01

In Indonesia ginger was usually used as a seasoning for dishes, an ingredient for beverage and a source of herbal medicines. Beside raw usage, ginger can be processed to obtain the essential oil which has many advantages such as proven to be an active antimicrobial and having an antioxidant ability. There are a lot of methods to extract essential oil from ginger, one of which is steam distillation. The aim of the current study was to investigate the effect of variation of time process and steam flow rate in the yield on ginger essential oil steam distillation extraction process. It was found that the best operation condition was 0.35 ml/s as the steam flow rate which yields 2.43% oil. The optimum time process was predicted at 7.5 hours. The composition of the oil was varied depend on the flow rate and every flow rate has its own major component contained in the oil. Curcumene composition in the oil was increased as increased steam flow rate applied, but the composition of camphene was decreased along with the increasing steam flow rate.

Bioelectrohydrogenesis and inhibition of methanogenic activity in microbial electrolysis cells - A review.

PubMed

Karthikeyan, Rengasamy; Cheng, Ka Yu; Selvam, Ammaiyappan; Bose, Arpita; Wong, Jonathan W C

2017-11-01

Microbial electrolysis cells (MECs) are a promising technology for biological hydrogen production. Compared to abiotic water electrolysis, a much lower electrical voltage (~0.2V) is required for hydrogen production in MECs. It is also an attractive waste treatment technology as a variety of biodegradable substances can be used as the process feedstock. Underpinning this technology is a recently discovered bioelectrochemical pathway known as "bioelectrohydrogenesis". However, little is known about the mechanism of this pathway, and numerous hurdles are yet to be addressed to maximize hydrogen yield and purity. Here, we review various aspects including reactor configurations, microorganisms, substrates, electrode materials, and inhibitors of methanogenesis in order to improve hydrogen generation in MECs. Copyright © 2017 Elsevier Inc. All rights reserved.

The determination of micro-arc plasma composition and properties of nanoparticles formed during cathodic plasma electrolysis of 304 stainless steel

NASA Astrophysics Data System (ADS)

Jovović, Jovica; Stojadinović, Stevan; Vasilić, Rastko; Tadić, Nenad; Šišović, Nikola M.

2017-05-01

This paper presents the research focused on the determination of micro-arc plasma composition during cathodic plasma electrolysis of AISI304 stainless steel in water solution of sodium hydroxide. The complex line shape of several Fe I spectral lines was observed and, by means of a dedicated fitting procedure based on the spectral line broadening theory and H2O thermal decomposition data, the mole fraction of micro-arc plasma constituents (H2, Fe, O, H, H2O, and OH) was determined. Subsequent characterization of the cathodic plasma electrolysis product formed during the process revealed that it consists of Fe-nanoparticles with median diameter of approximately 60 nm.

Electrochemical Treatment of Textile Dye Wastewater by Mild Steel Anode.

PubMed

Bhavya, J G; Rekha, H B; Murthy, Usha N

2014-04-01

This paper presents the results of the treatment of textile dye wastewater generated from a textile processing industry by electrochemical method. Experiments were conducted at current densities of 12, 24 and 48 A/m2 using mild steel as anode and cathode. During the various stages of electrolysis, parameters such as COD, color and BOD5 were determined in order to know the feasibility of electrochemical treatment. It was observed that increasing the electrolysis time and increased current density bring down the concentration of pollutants. Also COD removal rate and energy consumption during the electrolysis were calculated and presented in this paper. The present study proves the effectiveness of electrochemical treatment using MS as anode for TDW oxidation.

Degradation of Remazol Red in batik dye waste water by contact glow discharge electrolysis method using NaOH and NaCl electrolytes

NASA Astrophysics Data System (ADS)

Saksono, Nelson; Putri, Dita Amelia; Suminar, Dian Ratna

2017-03-01

Contact Glow Discharge Electrolysis (CGDE) method is one of Plasma Electrolysis technology which has been approved to degrade organic waste water because it is very productive in producing hydroxyl radical. This study aims to degrade Remazol Red by CGDE method and evaluate important parameters that have influent in degradation process of Remazol Red in Batik dye waste water in batch system. The kind of electrolyte (acid and base) and the addition of metal ion such as Fe2+ have affected Remazol Red degradation percentage. Ultraviolet-Visible (UV-Vis) absorption spectra were used to monitor the degradation process. The result of study showed that percentage degradation was 99.97% which obtained by using NaCl 0.02 M with addition Fe2+ 20 ppm, applied voltage 700 volt, anode depth 0.5 cm, initial concentration of Remazol Red 250 ppm and the temperature of solutions was maintained 50-60 ˚C.

Electrolysis of a molten semiconductor

DOE PAGES

Yin, Huayi; Chung, Brice; Sadoway, Donald R.

2016-08-24

Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb 2S 3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across themore » cell. In conclusion, as opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO 2, CO and SO 2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.« less

Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media.

PubMed

Lacasa, Engracia; Cañizares, Pablo; Llanos, Javier; Rodrigo, Manuel A

2012-04-30

In this work, the effect of the cathode material (conductive diamond, stainless steel, silicon carbide, graphite or lead) and the current density (150-1400 A m(-2)) on the removal of nitrates from aqueous solutions is studied by electrolysis in non-divided electrochemical cells equipped with conductive diamond anodes, using sodium sulphate as the electrolyte. The results show that the cathode material very strongly influences both the process performance and the product distribution. The main products obtained are gaseous nitrogen (NO, N(2)O and NO(2)) and ammonium ions. Nitrate removal follows first order kinetics, which indicates that the electrolysis process is controlled by mass transfer. Furthermore, the stainless steel and graphite cathodes show a great selectivity towards the production of ammonium ions, whereas the silicon carbide cathode leads to the highest formation of gaseous nitrogen, which production is promoted at low current densities. Copyright © 2012 Elsevier B.V. All rights reserved.

Formation of hazardous inorganic by-products during electrolysis of seawater as a disinfection process for desalination.

PubMed

Oh, Byung Soo; Oh, Sang Guen; Hwang, Youn Young; Yu, Hye-Weon; Kang, Joon-Wun; Kim, In S

2010-11-01

From our previous study, an electrochemical process was determined to be a promising tool for disinfection in a seawater desalination system, but an investigation on the production of several hazardous by-products is still required. In this study, a more intensive exploration of the formation patterns of perchlorate and bromate during the electrolysis of seawater was conducted. In addition, the rejection efficiencies of the targeted by-products by membrane processes (microfiltration and seawater reverse osmosis) were investigated to uncover the concentrations remaining in the final product from a membrane-based seawater desalination system for the production of drinking water. On the electrolysis of seawater, perchlorate did not provoke any problem due to the low concentrations formed, but bromate was produced at a much higher level, resulting in critical limitation in the application of the electrochemical process to the desalination of seawater. Even though the formed bromate was rejected via microfiltration and reverse osmosis during the 1st and 2nd passes, the residual concentration was a few orders of magnitude higher than the USEPA regulation. Consequently, it was concluded that the application of the electrochemical process to seawater desalination cannot be recommended without the control of bromate. Copyright © 2010 Elsevier B.V. All rights reserved.

Review of surface steam sterilization for validation purposes.

PubMed

van Doornmalen, Joost; Kopinga, Klaas

2008-03-01

Sterilization is an essential step in the process of producing sterile medical devices. To guarantee sterility, the process of sterilization must be validated. Because there is no direct way to measure sterility, the techniques applied to validate the sterilization process are based on statistical principles. Steam sterilization is the most frequently applied sterilization method worldwide and can be validated either by indicators (chemical or biological) or physical measurements. The steam sterilization conditions are described in the literature. Starting from these conditions, criteria for the validation of steam sterilization are derived and can be described in terms of physical parameters. Physical validation of steam sterilization appears to be an adequate and efficient validation method that could be considered as an alternative for indicator validation. Moreover, physical validation can be used for effective troubleshooting in steam sterilizing processes.

In situ analysis of chemical components induced by steaming between fresh ginseng, steamed ginseng, and red ginseng.

PubMed

In, Gyo; Ahn, Nam-Geun; Bae, Bong-Seok; Lee, Myoung-Woo; Park, Hee-Won; Jang, Kyoung Hwa; Cho, Byung-Goo; Han, Chang Kyun; Park, Chae Kyu; Kwak, Yi-Seong

2017-07-01

The chemical constituents of Panax ginseng are changed by processing methods such as steaming or sun drying. In the present study, the chemical change of Panax ginseng induced by steaming was monitored in situ . Samples were separated from the same ginseng root by incision during the steaming process, for in situ monitoring. Sampling was sequentially performed in three stages; FG (fresh ginseng) → SG (steamed ginseng) → RG (red ginseng) and 60 samples were prepared and freeze dried. The samples were then analyzed to determine 43 constituents among three stages of P. ginseng . The results showed that six malonyl-ginsenoside (Rg1, Rb1, Rb3, Rc, Rd, Rb2) and 15 amino acids were decreased in concentration during the steaming process. In contrast, ginsenoside-Rh1, 20( S )-Rg2, 20( S, R )-Rg3 and Maillard reaction product such as AF (arginine-fructose), AFG (arginine-fructose-glucose), and maltol were newly generated or their concentrations were increased. This study elucidates the dynamic changes in the chemical components of P. ginseng when the steaming process was induced. These results are thought to be helpful for quality control and standardization of herbal drugs using P. ginseng and they also provide a scientific basis for pharmacological research of processed ginseng (Red ginseng).

Electro Decomposition of Ammonia into Hydrogen for Fuel Cell Use

DTIC Science & Technology

2012-01-01

electrolyte for the experiments reflects the average amount of urea observed in human urine , 20 g/L/day. Figure 5 shows the flow dia- gram of a single cell...to improve the current density of the urea electrolysis process and to reduce the onset potential of the urea oxidation. The synthesis of layered...the new developments in the synthesis of nickel nanosheets can be coupled with the ammonia and urea electrolysis technology. This work concludes

Effect of soaking, boiling, and steaming on total phenolic contentand antioxidant activities of cool season food legumes.

PubMed

Xu, Baojun; Chang, Sam K C

2008-09-01

The effects of soaking, boiling and steaming processes on the total phenolic components and antioxidant activity in commonly consumed cool season food legumes (CSFL's), including green pea, yellow pea, chickpea and lentil were investigated. As compared to original unprocessed legumes, all processing steps caused significant (p<0.05) decreases in total phenolic content (TPC), DPPH free radical scavenging activity (DPPH) in all tested CSFL's. All soaking and atmospheric boiling treatments caused significant (p<0.05) decreases in oxygen radical absorbing capacity (ORAC). However, pressure boiling and pressure steaming caused significant (p<0.05) increases in ORAC values. Steaming treatments resulted in a greater retention of TPC, DPPH, and ORAC values in all tested CSFL's as compared to boiling treatments. To obtain cooked legumes with similar palatability and firmness, pressure boiling shortened processing time as compared to atmospheric boiling, resulted in insignificant differences in TPC, DPPH for green and yellow pea. However, TPC and DPPH in cooked lentils differed significantly between atmospheric and pressure boiling. As compared to atmospheric processes, pressure processes significantly increased ORAC values in both boiled and steamed CSFL's. Greater TPC, DPPH and ORAC values were detected in boiling water than that in soaking and steaming water. Boiling also caused more solid loss than steaming. Steam processing exhibited several advantages in retaining the integrity of the legume appearance and texture of the cooked product, shortening process time, and greater retention of antioxidant components and activities. Copyright © 2008 Elsevier Ltd. All rights reserved.

Distillate fuel-oil processing for phosphoric acid fuel cell power plants

NASA Astrophysics Data System (ADS)

1980-02-01

Efforts to develop distillate oil steam reforming processes are reviewed, and the applicability of these processes for integration with the fuel cell are discussed. The development efforts can be grouped into the following processing approaches: high temperature steam reforming; autothermal reforming; autothermal gasification; and ultra desulfurization followed by steam reforming. Sulfur in the feed is a problem in the process development.

Nonlinear time-series analysis of current signal in cathodic contact glow discharge electrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allagui, Anis, E-mail: aallagui@sharjah.ac.ae; Abdelkareem, Mohammad Ali; Rojas, Andrea Espinel

In the standard two-electrode configuration employed in electrolytic process, when the control dc voltage is brought to a critical value, the system undergoes a transition from conventional electrolysis to contact glow discharge electrolysis (CGDE), which has also been referred to as liquid-submerged micro-plasma, glow discharge plasma electrolysis, electrode effect, electrolytic plasma, etc. The light-emitting process is associated with the development of an irregular and erratic current time-series which has been arbitrarily labelled as “random,” and thus dissuaded further research in this direction. Here, we examine the current time-series signals measured in cathodic CGDE configuration in a concentrated KOH solution atmore » different dc bias voltages greater than the critical voltage. We show that the signals are, in fact, not random according to the NIST SP. 800-22 test suite definition. We also demonstrate that post-processing low-pass filtered sequences requires less time than the native as-measured sequences, suggesting a superposition of low frequency chaotic fluctuations and high frequency behaviors (which may be produced by more than one possible source of entropy). Using an array of nonlinear time-series analyses for dynamical systems, i.e., the computation of largest Lyapunov exponents and correlation dimensions, and re-construction of phase portraits, we found that low-pass filtered datasets undergo a transition from quasi-periodic to chaotic to quasi-hyper-chaotic behavior, and back again to chaos when the voltage controlling-parameter is increased. The high frequency part of the signals is discussed in terms of highly nonlinear turbulent motion developed around the working electrode.« less

Enhanced shock wave generation via pre-breakdown acceleration using water electrolysis in negative streamer pulsed spark discharges

NASA Astrophysics Data System (ADS)

Lee, Kern; Chung, Kyoung-Jae; Hwang, Y. S.

2018-03-01

This paper presents a method for enhancement of shock waves generated from underwater pulsed spark discharges with negative (anode-directed) subsonic streamers, for which the pre-breakdown process is accelerated by preconditioning a gap with water electrolysis. Hydrogen microbubbles are produced at the cathode by the electrolysis and move towards the anode during the preconditioning phase. The numbers and spatial distributions of the microbubbles vary with the amplitude and duration of each preconditioning pulse. Under our experimental conditions, the optimum pulse duration is determined to be ˜250 ms at a pulse voltage of 400 V, where the buoyancy force overwhelms the electric force and causes the microbubbles to be swept out from the water gap. When a high-voltage pulse is applied to the gap just after the preconditioning pulse, the pre-breakdown process is significantly accelerated in the presence of the microbubbles. At the optimum preconditioning pulse duration, the average breakdown delay is reduced by 87% and, more importantly, the energy consumed during the pre-breakdown period decreases by 83%. This reduced energy consumption during the pre-breakdown period, when combined with the morphological advantages of negative streamers, such as thicker and longer stalks, leads to a significant improvement in the measured peak pressure (˜40%) generated by the underwater pulsed spark discharge. This acceleration of pre-breakdown using electrolysis overcomes the biggest drawback of negative subsonic discharges, which is slow vapor bubble formation due to screening effects, and thus enhances the efficiency of the shock wave generation process using pulsed spark discharges in water.

Small-scale uses and costs of hydrogen derived from OTEC ammonia

NASA Astrophysics Data System (ADS)

Strickland, G.

Ocean Thermal Energy Conversion (OTEC) plantships could produce NH3 from air and water, using energy derived from thermal gradients in tropical oceans. NH3 can serve both as a commodity, for the fertilizer and chemical industries, and as a liquid energy carrier for fuel use. Attention is given to the economic prospects for using OTEC NH3 as a hydrogen transport and storage medium for small users who want to assess the purchase of hydrogen vs. the cost of producing hydrogen at their sites. Hydrogen is readily obtained from NH3 at the point of end use, by dissociation and purification as required, for use as a chemical commodity or fuel. It is shown that high-purity H2 derived from OTEC NH3 might be competitive with H2 made at the point of end use via water electrolysis, or via steam reforming of natural gas.

75 FR 68294 - Revisions to the California State Implementation Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... matter emissions from boilers, steam generators and process heaters greater than 5.0 MMbtu/hour. We are... Advance Emission 10/16/08 03/17/09 Reduction Options for Boilers, Steam Generators and Process Heaters..., steam generators and process heaters with a total rated heat input greater than 5 MMBtu/ hour. EPA's...

Biological denitrification process based on the Fe(0)-carbon micro-electrolysis for simultaneous ammonia and nitrate removal from low organic carbon water under a microaerobic condition.

PubMed

Deng, Shihai; Li, Desheng; Yang, Xue; Xing, Wei; Li, Jinlong; Zhang, Qi

2016-11-01

A combined process between micro-electrolysis and biological denitrification (MEBD) using iron scraps and an activated carbon-based micro-electrolysis carrier was developed for nitrogen removal under a microaerobic condition. The process provided NH4(+)-N and total nitrogen (TN) removal efficiencies of 92.6% and 95.3%, respectively, and TN removal rate of 0.373±0.11kgN/(m(3)d) at corresponding DO of 1.0±0.1mg/L and HRT of 3h, and the optimal pH of 7.6-8.4. High-throughput sequencing analysis verified that dominant classes belonged to β-, α-, and γ-Proteobacteria, and Nitrospira. The dominant genera Hydrogenophaga and Sphaerotilus significantly increased during the operation, covering 13.2% and 6.1% in biofilms attached to the carrier in the middle of the reactor, respectively. Autotrophic denitrification contributed to >80% of the TN removal. The developed MEBD achieved efficient simultaneous nitrification and autotrophic denitrification, presenting significant potential for application in practical low organic carbon water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preliminary System Analysis of In Situ Resource Utilization for Mars Human Exploration

NASA Technical Reports Server (NTRS)

Rapp, Donald; Andringa, Jason; Easter, Robert; Smith, Jeffrey H .; Wilson, Thomas; Clark, D. Larry; Payne, Kevin

2005-01-01

We carried out a system analysis of processes for utilization of Mars resources to support human exploration of Mars by production of propellants from indigenous resources. Seven ISRU processes were analyzed to determine mass. power and propellant storage volume requirements. The major elements of each process include C02 acquisition, chemical conversion, and storage of propellants. Based on a figure of merit (the ratio of the mass of propellants that must be brought from Earth in a non-ISRU mission to the mass of the ISRU system. tanks and feedstocks that must be brought from Earth for a ISRU mission) the most attractive process (by far); is one where indigenous Mars water is accessible and this is processed via Sabatier/Electrolysis to methane and oxygen. These processes are technically relatively mature. Other processes with positive leverage involve reverse water gas shift and solid oxide electrolysis.

Experiences with industrial solar process steam generation in Jordan

NASA Astrophysics Data System (ADS)

Krüger, Dirk; Berger, Michael; Mokhtar, Marwan; Willwerth, Lisa; Zahler, Christian; Al-Najami, Mahmoud; Hennecke, Klaus

2017-06-01

At the Jordanian pharmaceuticals manufacturing company RAM Pharma a solar process heat supply has been constructed by Industrial Solar GmbH in March 2015 and operated since then (Figure 1). The collector field consists of 394 m² of linear Fresnel collectors supplying saturated steam to the steam network at RAM Pharma at about 6 bar gauge. In the frame of the SolSteam project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) the installation has been modified introducing an alternative way to separate water and steam by a cyclone. This paper describes the results of experiments with the cyclone and compares the operation with a steam drum. The steam production of the solar plant as well as the fuel demand of the steam boiler are continuously monitored and results are presented in this paper.

Invited review: summary of steam-flaking corn or sorghum grain for lactating dairy cows.

PubMed

Theurer, C B; Huber, J T; Delgado-Elorduy, A; Wanderley, R

1999-09-01

Nineteen lactation trials (43 grain processing comparisons) are summarized, in addition to digestibility and postabsorptive metabolism studies. The net energy for lactation (NEL) of steam-flaked corn or sorghum grain is about 20% greater than the NEL for dry-rolled corn or sorghum. Based on lactational performance, steam-flaked sorghum grain is of equal value to steam-flaked corn, and steam-flaked corn is superior to steam-rolled corn. Steam-flaking of corn or sorghum compared to steam-rolling of corn or dry-rolling of corn or sorghum consistently improves milk production and milk protein yield. This result is because of a much greater proportion of dietary starch fermented in the rumen, enhanced digestibility of the smaller fraction of dietary starch reaching the small intestine, and increased total starch digestion. Steam-flaking increases cycling of urea to the gut, microbial protein flow to the small intestine, and estimated mammary uptake of amino acids. Steam-rolling compared to dry-rolling of barley or wheat did not alter total starch digestibilities in two trials, one with each grain source. Lactation studies with these processing comparisons have not been reported. Most cited studies have been with total mixed rations (TMR) and alfalfa hay as the principal forage. Additional studies are needed with lactating cows fed steam-flaked corn or sorghum in TMR containing alfalfa or corn silage. Optimal flake density of steam-processed corn or sorghum grain appears to be about 360 g/L (approximately 28 lb/bu).

Production of synthetic fuels using syngas from a steam hydrogasification and reforming process

NASA Astrophysics Data System (ADS)

Raju, Arun Satheesh Kumar

This thesis is aimed at the research, optimization and development of a thermo-chemical process aimed at the production of synthesis gas (mixture of H2 and CO) with a flexible H2 to CO ratio using coupled steam hydrogasification and steam reforming processes. The steam hydrogasification step generates a product gas containing significant amounts of methane by gasifying a carbonaceous feed material with steam and internally generated H2. This product gas is converted to synthesis gas with an excess H2 to CO using the steam reformer. Research involving experimental and simulation work has been conducted on steam hydrogasification, steam reforming and the Fischer-Tropsch reaction. The Aspen Plus simulation tool has been used to develop a process model that can perform heat and mass balance calculations of the whole process using built-in reactor modules and an empirical FT model available in the literature. This model has been used to estimate optimum feed ratios and process conditions for specific feedstocks and products. Steam hydrogasification of coal and wood mixtures of varying coal to wood ratios has been performed in a stirred batch reactor. The carbon conversion of the feedstocks to gaseous products is around 60% at 700°C and 80% at 800°C. The coal to wood ratio of the feedstock does not exert a significant influence on the carbon conversion. The rates of formation of CO, CO 2 and CH4 during gasification have been calculated based on the experimental results using a simple kinetic model. Experimental research on steam reforming has been performed. It has been shown that temperature and the feed CO2/CH4 ratio play a dominant role in determining the product gas H2/CO ratio. Reforming of typical steam hydrogasification product-gas stream has been investigated over a commercial steam reforming catalyst. The results demonstrate that the combined use of steam hydrogasification process with a reformer can generate a synthesis gas with a predetermined H2/CO ratio from carbonaceous feedstocks. Experimental work on the Fischer-Tropsch synthesis has also been performed. A life cycle analysis has been performed with the objective of comparing the life cycle energy consumption and emissions of synthetic diesel fuel produced through the CE-CERT process with other fuel/vehicle combinations. The experimental and simulation results presented here demonstrate that the CE-CERT process is versatile and can potentially handle a number of different feedstocks. CE-CERT process appears to be suitable for commercialization in very large scales with a coal feedstock and also in a distributed network of smaller scale reactors utilizing localized renewable feedstocks.

One-Step Coal Liquefaction

NASA Technical Reports Server (NTRS)

Qader, S. A.

1984-01-01

Steam injection improves yield and quality of product. Single step process for liquefying coal increases liquid yield and reduces hydrogen consumption. Principal difference between this and earlier processes includes injection of steam into reactor. Steam lowers viscosity of liquid product, so further upgrading unnecessary.

Lunar oxygen and metal for use in near-earth space - Magma electrolysis

NASA Technical Reports Server (NTRS)

Colson, Russell O.; Haskin, Larry A.

1990-01-01

The unique conditions on the moon, such as vacuum, absence of many reagents common on the earth, and presence of very nontraditional 'ores', suggest that a unique and nontraditional process for extracting materials from the ores may prove the most practical. An investigation has begun into unfluxed silicate electrolysis as a method for extracting oxygen, Fe, and Si from lunar regolith. The advantages of the process include simplicity of concept, absence of need to supply reagents from the earth, and low power and mass requirements for the processing plant. Disadvantages include the need for uninterrupted high temperature and the highly corrosive nature of the high-temperature silicate melts, which has made identifying suitable electrode and container materials difficult.

A Novel Method for Preparing Auxetic Foam from Closed-cell Polymer Foam Based on Steam Penetration and Condensation (SPC) Process.

PubMed

Fan, Donglei; Li, Minggang; Qiu, Jian; Xing, Haiping; Jiang, Zhiwei; Tang, Tao

2018-05-31

Auxetic materials are a class of materials possessing negative Poisson's ratio. Here we establish a novel method for preparing auxetic foam from closed-cell polymer foam based on steam penetration and condensation (SPC) process. Using polyethylene (PE) closed-cell foam as an example, the resultant foams treated by SPC process present negative Poisson's ratio during stretching and compression testing. The effect of steam-treated temperature and time on the conversion efficiency of negative Poisson's ratio foam is investigated, and the mechanism of SPC method for forming re-entrant structure is discussed. The results indicate that the presence of enough steam within the cells is a critical factor for the negative Poisson's ratio conversion in the SPC process. The pressure difference caused by steam condensation is the driving force for the conversion from conventional closed-cell foam to the negative Poisson's ratio foam. Furthermore, the applicability of SPC process for fabricating auxetic foam is studied by replacing PE foam by polyvinyl chloride (PVC) foam with closed-cell structure or replacing water steam by ethanol steam. The results verify the universality of SPC process for fabricating auxetic foams from conventional foams with closed-cell structure. In addition, we explored potential application of the obtained auxetic foams by SPC process in the fabrication of shape memory polymer materials.

Fabrication and characterization of the organic rectifying junctions by electrolysis

NASA Astrophysics Data System (ADS)

Karimov, Khasan; Ahmad, Zubair; Ali, Rashid; Noor, Adnan; Akmal, M.; Najeeb, M. A.; Shakoor, R. A.

2017-08-01

Unlike the conventional solution processable deposition techniques, in this study, we propose a novel and economical method for the fabrication of organic rectifying junctions. The solutions of the orange dye, copper phthalocyanine and NaCl were deposited on the surface-type interdigitated silver electrodes using electrolysis technique. Using the current-voltage (I-V) characteristics, the presence of rectifying behavior in the samples has been confirmed. This phenomenon, in principle, can be used for fabrication of the diodes, transistors and memory devices.

ELECTROLYTIC PRODUCTION OF URANIUM TETRAFLUORIDE

DOEpatents

Lofthouse, E.

1954-08-31

This patent relates to electrolytic methods for the production of uranium tetrafluoride. According to the present invention a process for the production of uranium tetrafluoride comprises submitting to electrolysis an aqueous solution of uranyl fluoride containing free hydrofluoric acid. Advantageously the aqueous solution of uranyl fluoride is obtained by dissolving uranium hexafluoride in water. On electrolysis, the uranyl ions are reduced to uranous tons at the cathode and immediately combine with the fluoride ions in solution to form the insoluble uranium tetrafluoride which is precipitated.

Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

DOEpatents

Tiernan, Joan E.

1991-01-01

Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and l BACKGROUND OF THE INVENTION The invention described herein arose in the course of, or under, Contract No. DE-AC03-76SF00098 between the U.S. Department of Energy and the University of California.

Preparation of Ferrotitanium from Ilmenite by Electrolysis-Assisted Calciothermic Reduction in CaCl2-NaCl Molten Salt

NASA Astrophysics Data System (ADS)

Zhou, Zhongren; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Gong, Kai; Ru, Juanjian; Xiong, Li

2016-02-01

Electrolysis-assisted calciothermic reduction method is proposed and successfully used to prepare ferrotitanium alloy from ilmenite by using equal-molar CaCl2-NaCl molten salt as electrolyte, molybdenum rod as cathode, and graphite as anode at 973 K with cell voltages of 3.2-4.4 V under inert atmosphere. Thermodynamics analysis of the process is presented, and the products obtained are examined with x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. It is demonstrated that the calciothermic reduction of ilmenite is a stepwise process since intermediate CaTiO3 is observed in the products partially reduced. In the calciothermic reduction process, the reduction of FeTiO3 first gives rise to the formation of Fe and CaTiO3, which as intermediates will further react with calcium metal to form ferrotitanium alloys. This is in good agreement with the prediction of thermodynamics. Experimental results also show that increasing cell voltage can accelerate the formation of calcium metal through electrolysis of CaO and CaCl2 and, hence, promote the calciothermic reduction of ilmenite. As the electrolytic zone and reduction zone are combined in the same bath, the theoretical energy requirement for the production of FeTi in the calciothermic process is lower than that in the aluminothermic process.

Actual operation and regulatory activities on steam generator replacement in Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saeki, Hitoshi

1997-02-01

This paper summarizes the operating reactors in Japan, and the status of the steam generators in these plants. It reviews plans for replacement of existing steam generators, and then goes into more detail on the planning and regulatory steps which must be addressed in the process of accomplishing this maintenance. The paper also reviews the typical steps involved in the process of removal and replacement of steam generators.

Composite fuel electrode La(0.2)Sr(0.8)TiO(3-δ)-Ce(0.8)Sm(0.2)O(2-δ) for electrolysis of CO2 in an oxygen-ion conducting solid oxide electrolyser.

PubMed

Li, Yuanxin; Zhou, Jianer; Dong, Dehua; Wang, Yan; Jiang, J Z; Xiang, Hongfa; Xie, Kui

2012-11-28

Composite Ni-YSZ fuel electrodes are able to operate only under strongly reducing conditions for the electrolysis of CO(2) in oxygen-ion conducting solid oxide electrolysers. In an atmosphere without a flow of reducing gas (i.e., carbon monoxide), a composite fuel electrode based on redox-reversible La(0.2)Sr(0.8)TiO(3+δ) (LSTO) provides a promising alternative. The Ti(3+) was approximately 0.3% in the oxidized LSTO (La(0.2)Sr(0.8)TiO(3.1)), whereas the Ti(3+) reached approximately 8.0% in the reduced sample (La(0.2)Sr(0.8)TiO(3.06)). The strong adsorption of atmospheric oxygen in the form of superoxide ions led to the absence of Ti(3+) either on the surface of oxidized LSTO or the reduced sample. Reduced LSTO showed typical metallic behaviour from 50 to 700 °C in wet H(2); and the electrical conductivity of LSTO reached approximately 30 S cm(-1) at 700 °C. The dependence of [Ti(3+)] concentration in LSTO on P(O(2)) was correlated to the applied potentials when the electrolysis of CO(2) was performed with the LSTO composite electrode. The electrochemical reduction of La(0.2)Sr(0.8)TiO(3+δ) was the main process but was still present up to 2 V at 700 °C during the electrolysis of CO(2); however, the electrolysis of CO(2) at the fuel electrode became dominant at high applied voltages. The current efficiency was approximately 36% for the electrolysis of CO(2) at 700 °C and a 2 V applied potential.

Parameter optimization of electrolytic process of obtaining sodium hypochlorite for disinfection of water

NASA Astrophysics Data System (ADS)

Bogoslovskii, S. Yu; Kuznetsov, N. N.; Boldyrev, V. S.

2017-11-01

Electrochlorination parameters were optimized in flowing and non-flowing modes for a cell with a volume of 1 l. At a current density of 0.1 A/cm2 in the range of flow rates from 0.8 to 6.0 l/h with a temperature of the initial solution below 20°C the outlet temperature is maintained close to the optimal 40°C. The pH of the solution during electrolysis increases to 8.8 ÷ 9.4. There was studied a process in which a solution with a temperature of 7-8°C and a concentration of sodium chloride of 25 and 35 g/l in non-flowing cell was used. The dependence of the concentration of active chlorine on the electrolysis time varies with the concentration of the initial solution of sodium chloride. In case of chloride concentration of 25 g/l virtually linear relationship makes it easy to choose the time of electrolysis with the aim of obtaining the needed concentration of the product.

Nitrate removal and microbial analysis by combined micro-electrolysis and autotrophic denitrification.

PubMed

Xing, Wei; Li, Desheng; Li, Jinlong; Hu, Qianyi; Deng, Shihai

2016-07-01

A process combining micro-electrolysis and autotrophic denitrification (CEAD) with iron-carbon micro-electrolysis carriers was developed for nitrate removal. The process was performed using organic-free influent with a NO3(-)-N concentration of 40.0±3.0mg/L and provided an average nitrate removal efficiency of 95% in stable stages. The total nitrogen removal efficiency reached 75%, with 21% of NO3(-)-N converted into NH4(+)-N. The corresponding hydraulic retention time was 8-10h, and the optimal pH ranged from 8.5 to 9.5. Microbial analysis with high-throughput sequencing revealed that dominant microorganisms in the reactor belonged to the classes of β-, γ-, and α-Proteobacteria. The abundance of the genera Thermomonas significantly increased during the operation, comprising 21.4% and 24.1% in sludge attached to the carriers in the middle and at the bottom of the reactor, respectively. The developed CEAD achieved efficient nitrate removal from water without organics, which is suitable for practical application. Copyright © 2016. Published by Elsevier Ltd.

Denitrification using a monopolar electrocoagulation/flotation (ECF) process.

PubMed

Emamjomeh, Mohammad M; Sivakumar, Muttucumaru

2009-01-01

Nitrate levels are limited due to health concerns in potable water. Nitrate is a common contaminant in water supplies, and especially prevalent in surface water supplies and shallow wells. Nitrate is a stable and highly soluble ion with low potential for precipitation or adsorption. These properties make it difficult to remove using conventional water treatment methods. A laboratory batch electrocoagulation/flotation (ECF) reactor was designed to investigate the effects of different parameters such as electrolysis time, electrolyte pH, initial nitrate concentration, and current rate on the nitrate removal efficiency. The optimum nitrate removal was observed at a pH range of between 9 and 11. It appeared that the nitrate removal rate was 93% when the initial nitrate concentration and electrolysis time respectively were 100 mg L(-1)-NO(3)(-) and 40 min. The results showed a linear relationship between the electrolysis time for total nitrate removal and the initial nitrate concentration. It is concluded that the electrocoagulation technology for denitrification can be an effective preliminary process when the ammonia byproduct must be effectively removed by the treatment facilities.

Lifetime of Sodium Beta-Alumina Membranes in Molten Sodium Hydroxide

DTIC Science & Technology

2008-07-01

ABSTRACT Summary: Sodium metal can be made by electrolysis of molten sodium hydroxide in sodium beta-alumina membrane electrolysis cells... electrolysis of molten sodium hydroxide in sodium ”-alumina membrane electrolysis cells. However, there are some uncertainties about the lifetime of the...the properties of the membrane degrade upon long term contact with molten sodium hydroxide. Electrolysis cells were designed, but it proved

Application of Fourier transform near-infrared spectroscopy to optimization of green tea steaming process conditions.

PubMed

Ono, Daiki; Bamba, Takeshi; Oku, Yuichi; Yonetani, Tsutomu; Fukusaki, Eiichiro

2011-09-01

In this study, we constructed prediction models by metabolic fingerprinting of fresh green tea leaves using Fourier transform near-infrared (FT-NIR) spectroscopy and partial least squares (PLS) regression analysis to objectively optimize of the steaming process conditions in green tea manufacture. The steaming process is the most important step for manufacturing high quality green tea products. However, the parameter setting of the steamer is currently determined subjectively by the manufacturer. Therefore, a simple and robust system that can be used to objectively set the steaming process parameters is necessary. We focused on FT-NIR spectroscopy because of its simple operation, quick measurement, and low running costs. After removal of noise in the spectral data by principal component analysis (PCA), PLS regression analysis was performed using spectral information as independent variables, and the steaming parameters set by experienced manufacturers as dependent variables. The prediction models were successfully constructed with satisfactory accuracy. Moreover, the results of the demonstrated experiment suggested that the green tea steaming process parameters could be predicted on a larger manufacturing scale. This technique will contribute to improvement of the quality and productivity of green tea because it can objectively optimize the complicated green tea steaming process and will be suitable for practical use in green tea manufacture. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Oxygen and iron production by electrolytic smelting of lunar soil

NASA Technical Reports Server (NTRS)

Colson, R. O.; Haskin, L. A.

1992-01-01

Work during the past year involved two aspects: (1) electrolysis experiments on a larger scale than done before, and (2) collaboration with Carbotek Inc. on design for a lunar magma electrolysis cell. It was demonstrated previously that oxygen can be produced by direct electrolysis of silicate melts. Previous experiments using 50-100 mg of melt have succeeded in measuring melt resistivities, oxygen production efficiencies, and have identified the character of metal products. A series of experiments using 1-8 grams of silicate melt, done in alumina and spinel containers sufficiently large that surface tension effects between the melt and the wall are expected to have minor effect on the behavior of the melt in the region of the electrodes were completed. The purpose of these experiments was to demonstrate the durability of the electrode and container materials, demonstrate the energy efficiency of the electrolysis process, further characterize the nature of the expected metal and spinel products, measure the efficiency of oxygen production and compare to that predicted on the basis of the smaller-scale experiments, and identify any unexpected benefits or problems of the process. Four experimental designs were employed. Detailed results of these experiments are given in the appendix ('Summary of scaling-up experiments'); a general report of the results is given in terms of implications of the experiments on container materials, cathode materials, anode materials, bubble formation and frothing of the melt, cell potential, anode-cathode distance, oxygen efficiency, and energy efficiency.

Electrolysis-driven bioremediation of crude oil-contaminated marine sediments.

PubMed

Bellagamba, Marco; Cruz Viggi, Carolina; Ademollo, Nicoletta; Rossetti, Simona; Aulenta, Federico

2017-09-25

Bioremediation is an effective technology to tackle crude oil spill disasters, which takes advantage of the capacity of naturally occurring microorganisms to degrade petroleum hydrocarbons under a range of environmental conditions. The enzymatic process of breaking down oil is usually more rapid in the presence of oxygen. However, in contaminated sediments, oxygen levels are typically too low to sustain the rapid and complete biodegradation of buried hydrocarbons. Here, we explored the possibility to electrochemically manipulate the redox potential of a crude oil-contaminated marine sediment in order to establish, in situ, conditions that are conducive to contaminants biodegradation by autochthonous microbial communities. The proposed approach is based on the exploitation of low-voltage (2V) seawater electrolysis to drive oxygen generation (while minimizing chlorine evolution) on Dimensionally Stable Anodes (DSA) placed within the contaminated sediment. Results, based on a laboratory scale setup with chronically polluted sediments spiked with crude oil, showed an increased redox potential and a decreased pH in the vicinity of the anode of 'electrified' treatments, consistent with the occurrence of oxygen generation. Accordingly, hydrocarbons biodegradation was substantially accelerated (up to 3-times) compared to 'non-electrified' controls, while sulfate reduction was severely inhibited. Intermittent application of electrolysis proved to be an effective strategy to minimize the energy requirements of the process, without adversely affecting degradation performance. Taken as a whole, this study suggests that electrolysis-driven bioremediation could be a sustainable technology for the management of contaminated sediments. Copyright © 2016 Elsevier B.V. All rights reserved.

Decolorization of distillery spent wash effluent by electro oxidation (EC and EF) and Fenton processes: A comparative study.

PubMed

David, Charles; Arivazhagan, M; Tuvakara, Fazaludeen

2015-11-01

In this study, laboratory scale experiments were performed to degrade highly concentrated organic matter in the form of color in the distillery spent wash through batch oxidative methods such as electrocoagulation (EC), electrofenton (EF) and Fenton process. The effect of corresponding operating parameters, namely initial pH: 2-10; current intensity: 1-5A; electrolysis time: 0.5-4h; agitation speed: 100-500rpm; inter-electrode distance: 0.5-4cm and Fenton's reagent dosage: 5-40mg/L was employed for optimizing the process of spent wash color removal. The performance of all the three processes was compared and assessed in terms of percentage color removal. For EC, 79% color removal was achieved using iron electrodes arranged with 0.5cm of inter-electrode space and at optimum conditions of pH 7, 5A current intensity, 300rpm agitation speed and in 2h of electrolysis time. In EF, 44% spent wash decolorization was observed using carbon (graphite) electrodes with an optimum conditions of 0.5cm inter-electrode distance, pH 3, 4A current intensity, 20mg/L FeSO4 and agitation speed of 400rpm for 3h of electrolysis time. By Fenton process, 66% decolorization was attained by Fenton process at optimized conditions of pH 3, 40mg/L of Fenton's reagent and at 500rpm of agitation speed for 4h of treatment time. Copyright © 2015 Elsevier Inc. All rights reserved.

Hydrogen fuel dispensing station for transportation vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, S.P.N.; Richmond, A.A.

1995-07-01

A technical and economic assessment is being conducted of a hydrogen fuel dispensing station to develop an understanding of the infrastructure requirements for supplying hydrogen fuel for mobile applications. The study includes a process design of a conceptual small-scale, stand-alone, grassroots fuel dispensing facility (similar to the present-day gasoline stations) producing hydrogen by steam reforming of natural gas. Other hydrogen production processes (such as partial oxidation of hydrocarbons and water electrolysis) were reviewed to determine their suitability for manufacturing the hydrogen. The study includes an assessment of the environmental and other regulatory permitting requirements likely to be imposed on amore » hydrogen fuel dispensing station for transportation vehicles. The assessment concludes that a dispensing station designed to produce 0.75 million standard cubic feet of fuel grade (99.99%+ purity) hydrogen will meet the fuel needs of 300 light-duty vehicles per day. Preliminary economics place the total capital investment (in 1994 US dollars) for the dispensing station at $4.5 million and the annual operating costs at around $1 million. A discounted cash-flow analysis indicates that the fuel hydrogen product price (excluding taxes) to range between $1.37 to $2.31 per pound of hydrogen, depending upon the natural gas price, the plant financing scenario, and the rate of return on equity capital. A report on the assessment is due in June 1995. This paper presents a summary of the current status of the assessment.« less

Lunar Metal Oxide Electrolysis with Oxygen and Photovoltaic Array Production Applications

NASA Technical Reports Server (NTRS)

Curreri, P. A.; Ethridge, E.; Hudson, S.; Sen, S.

2006-01-01

This paper presents the results of a Marshall Space Flight Center funded effort to conduct an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis (MOE) process to produce oxygen and metal from lunar resources to support human exploration of space. Oxygen extracted from lunar materials can be used for life support and propellant, and silicon and metallic elements produced can be used for in situ fabrication of thin-film solar cells for power production. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis, MOE, is chosen for extraction, since the electron is the most practical reducing agent. MOE was also chosen for following reasons. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. In the experiments reported here, melts containing iron oxide were electrolyzed in a low temperature supporting oxide electrolyte (developed by D. Sadoway, MIT). The production of oxygen and reduced iron were observed. Electrolysis was also performed on the supporting electrolyte with JSC-1 Lunar Simulant. The cell current for the supporting electrolyte alone is negligible while the current for the electrolyte with JSC-1 shows significant current and a peak at about -0.6 V indicating reductive reaction in the simulant.

The Scientific Papers of James Prescott Joule 2 Volume Set

NASA Astrophysics Data System (ADS)

Prescott Joule, James

2011-03-01

Volume 1: Description of an electro-magnetic engine; Description of an electro-magnetic engine, with experiments; On the use of electro-magnets made of iron wire for the electro-magnetic engine; Investigations in magnetism and electro-magnetism; Investigations in magnetism and electro-magnetism; Description of an electro-magnetic engine; On electro-magnetic forces; On electro-magnetic forces; On electro-magnetic forces; Description of a new electro-magnet; On a new class of magnetic forces; On voltaic apparatus; On the production of heat by voltaic electricity; On the heat evolved by metallic conductors of electricity, and in the cells of a battery during electrolysis; On the electric origin of the heat of combustion; On the electrical origin of chemical heat; On Sir G. C. Haughton's experiments; On the heat evolved during the electrolysis of water; On the calorific effects of magneto-electricity, and on the mechanical value of heat; On the intermittent character of the voltaic current in certain cases of electrolysis; and on the intensities of various voltaic arrangements; On the changes of temperature produced by the rarefaction and condensation of air; On specific heat; On a new method for ascertaining the specific heat of bodies; Note on the employment of electrical currents for ascertaining the specific heat of bodies; On the mechanical equivalent of heat; On the existence of an equivalent relation between heat and the ordinary forms of mechanical power; On the heat disengaged in chemical combinations; On the effects of magnetism upon the dimensions of iron and steel bars; On matter, living force, and heat; On the mechanical equivalent of heat, as determined from the heat evolved by the function of fluids; On the theoretical velocity of sound; Expériences sur l'identité entre le calorique et la force méchanique. Détermination de l'équivalent par la chaleur dégagée pendant la friction du mercure; On shooting-stars; On the mechanical equivalent of heat, and on the constitution of elastic fluids; Some remarks on heat and the constitution of elastic fluids; On the mechanical equivalent of heat; On a remarkable appearance of lightning; On some amalgams; On the air-engine; Account of experiments with a powerful electro-magnet; On the economical production of mechanical effect from chemical forces; An account of some experiments with a large electro-magnet; Introductory research on the induction of magnetism by electric currents; On the fusion of metals by voltaic electricity; Note on Dalton's determination of the expansion of air by heat; On the utilization of the sewage of London and other large towns; Notice of experiments on the heat developed by friction in air; On the intensity of light during the recent solar eclipse; On an improved galvanometer; On the thermo-electricity of ferruginous metals, and on the thermal effects of stretching solid bodies; On the thermal effects of longitudinal compression of solids, with an investigation on the alterations of temperature accompanying changes of pressure in fluids; On some thermo-dynamic properties of solids; On the thermal effects of compressing fluids; On a method of testing the strength of steam-boilers; Experiments on the total heat of steam; Experiments on the passage of air through pipes and apertures in thin plates; On some amalgams; On the probable cause of electric storms; On the surface-condensation of steam; Notice of a compressing air-pump; Note on a mirage at Douglas; On a sensitive barometer; On a sensitive thermometer; Note on the meteor of February 6th, 1818; On a method of hardening steel wires for magnetic needles; On an instrument for showing rapid changes in magnetic declination; Determination of the dynamical equivalent of heat from the thermal effects of electric currents; Observations on the alteration of the freezing-point in thermometers; On a new

Magnesium Recycling of Partially Oxidized, Mixed Magnesium-Aluminum Scrap through Combined Refining and Solid Oxide Membrane Electrolysis Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiaofei Guan; Peter A. Zink; Uday B. Pal

2012-01-01

Pure magnesium (Mg) is recycled from 19g of partially oxidized 50.5wt.% Mg-Aluminum (Al) alloy. During the refining process, potentiodynamic scans (PDS) were performed to determine the electrorefining potential for magnesium. The PDS show that the electrorefining potential increases over time as the magnesium content inside the Mg-Al scrap decreases. Up to 100% percent of magnesium is refined from the Mg-Al scrap by a novel refining process of dissolving magnesium and its oxide into a flux followed by vapor phase removal of dissolved magnesium and subsequently condensing the magnesium vapor. The solid oxide membrane (SOM) electrolysis process is employed in themore » refining system to enable additional recycling of magnesium from magnesium oxide (MgO) in the partially oxidized Mg-Al scrap. The combination of the refining and SOM processes yields 7.4g of pure magnesium.« less

40 CFR 429.80 - Applicability; description of the wood preserving-steam subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the wood... Wood Preserving Steam Subcategory § 429.80 Applicability; description of the wood preserving—steam... process wastewater pollutants into publicly owned treatment works from wood preserving processes that use...

40 CFR 429.80 - Applicability; description of the wood preserving-steam subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the wood... Wood Preserving Steam Subcategory § 429.80 Applicability; description of the wood preserving—steam... process wastewater pollutants into publicly owned treatment works from wood preserving processes that use...

40 CFR 429.80 - Applicability; description of the wood preserving-steam subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the wood... Wood Preserving Steam Subcategory § 429.80 Applicability; description of the wood preserving—steam... process wastewater pollutants into publicly owned treatment works from wood preserving processes that use...

Pretreatment effects on orange processing waste for making ethanol by simultaneous saccharification and fermentation

USDA-ARS?s Scientific Manuscript database

Pretreatment of orange processing waste (CPW) by steam explosion under various conditions (pretreatment time, pH and temperatures) was investigated. Pretreatments longer than 4 min with steam purging resulted in CPW containing less than 0.1% limonene, an inhibitor for fermentation. Steam pretreatmen...

Conversion of Carbon Dioxide into Ethanol by Electrochemical Synthesis Method Using Cu-Zn Electrode

NASA Astrophysics Data System (ADS)

Riyanto; Ramadan, S.; Fariduddin, S.; Aminudin, A. R.; Hayatri, A. K.

2018-01-01

Research on conversion of carbon dioxide into ethanol has been done. The conversion process is carried out in a sodium bicarbonate electrolyte solution in an electrochemical synthesis reactor. As cathode was used Cu-Zn, while as anode carbon was utilized. Variations of voltage, concentration of sodium bicarbonate electrolyte solution and time of electrolysis were performed to determine the optimum conditions to convert carbon dioxide into ethanol. Sample of the electrochemical synthesis process was analyzed by gas chromatography. From the result, it is found that the optimum conditions of the electrochemical synthesis process of carbon dioxide conversion into ethanol are voltage, concentration of sodium bicarbonate electrolyte solution and time of electrolysis are 3 volts, 0.4 M and 90 minutes with the ethanol concentration of 10.44%.

Process Demonstration For Lunar In Situ Resource Utilization-Molten Oxide Electrolysis (MSFC Independent Research and Development Project No. 5-81)

NASA Technical Reports Server (NTRS)

Curreri, P. A.; Ethridge, E. C.; Hudson, S. B.; Miller, T. Y.; Grugel, R. N.; Sen, S.; Sadoway, D. R.

2006-01-01

The purpose of this Focus Area Independent Research and Development project was to conduct, at Marshall Space Flight Center, an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis process to produce oxygen and metal. In essence, the vision was to develop two key technologies, the first to produce materials (oxygen, metals, and silicon) from lunar resources and the second to produce energy by photocell production on the Moon using these materials. Together, these two technologies have the potential to greatly reduce the costs and risks of NASA s human exploration program. Further, it is believed that these technologies are the key first step toward harvesting abundant materials and energy independent of Earth s resources.

ISRU Technologies for Mars Life Support

NASA Technical Reports Server (NTRS)

Finn, John E.; Kliss, Mark; Sridhar, K. R.; Iacomini, Christie

2001-01-01

Life support systems can take advantage of elements in the atmosphere of Mars to provide for necessary consumables such as oxygen and buffer gas for makeup of leakage. In situ consumables production (ISCP) can be performed effectively in conjunction with in situ propellant production, in which oxygen and methane are manufactured for rocket fuel. This project considers ways of achieving the optimal system objectives from the two sometimes competing objectives of ISPP and ISCP. In previous years we worked on production of a nitrogen-argon buffer gas as a by- product of the CO2 acquisition and compression system. Recently we have been focusing on combined electrolysis of water vapor and carbon dioxide. Combined electrolysis of water vapor and carbon dioxide is essential for reducin,o the complexity of a combined ISPP/ISCP plant. Using a solid oxide electrolysis cell (SOEC) for this combined process would be most advantageous for it allows mainly gas phase reactions, O2 gas delivered from the electrolyzer is free of any H2O vapor, and SOE is already a proven technology for pure CO2 electrolysis. Combined SOEC testing is conducted at The University of Arizona in the Space Technologies Laboratory (STL) of the Aerospace and Mechanical Engineering Department.

Process for purifying geothermal steam

DOEpatents

Li, Charles T.

1980-01-01

Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

Process for purifying geothermal steam

DOEpatents

Li, C.T.

Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwin A. Harvego; James E. O'Brien; Michael G. McKellar

2012-11-01

Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimization of the design using a detailed process flow sheet and realistic operating conditions specified by the analyst. The lifecycle cost analysismore » was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.« less

Composite membranes for alkaline electrolysis based on polysulfone and mineral fillers

NASA Astrophysics Data System (ADS)

Burnat, Dariusz; Schlupp, Meike; Wichser, Adrian; Lothenbach, Barbara; Gorbar, Michal; Züttel, Andreas; Vogt, Ulrich F.

2015-09-01

Mineral-based membranes for high temperature alkaline electrolysis were developed by a phase inversion process with polysulfone as binder. The long-term stability of new mineral fillers: wollastonite, forsterite and barite was assessed by 8000 h-long leaching experiments (5.5 M KOH, 85 °C) combined with thermodynamic modelling. Barite has released only 6.22 10-4 M of Ba ions into the electrolyte and was selected as promising filler material, due to its excellent stability. Barite-based membranes, prepared by the phase inversion process, were further studied. The resistivity of these membranes in 5.5 M KOH was investigated as a function of membrane thickness and total porosity, hydrodynamic porosity as well as gas purities determined by conducting electrolysis at ambient conditions. It was found that a dense top layer resulting from the phase inversion process, shows resistivity values up to 451.0 ± 22 Ω cm, which is two orders of magnitude higher than a porous bulk membrane microstructure (3.89 Ω cm). Developed membranes provided hydrogen purity of 99.83 at 200 mA cm-2, which is comparable to previously used chrysotile membranes and higher than commercial state-of-the-art Zirfon 500utp membrane. These cost-effective polysulfone - barite membranes are promising candidates as asbestos replacement for commercial applications.

DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

EPA Science Inventory

Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

Integrated gasifier combined cycle polygeneration system to produce liquid hydrogen

NASA Technical Reports Server (NTRS)

Burns, R. K.; Staiger, P. J.; Donovan, R. M.

1982-01-01

An integrated gasifier combined cycle (IGCC) system which simultaneously produces electricity, process steam, and liquid hydrogen was evaluated and compared to IGCC systems which cogenerate electricity and process steam. A number of IGCC plants, all employing a 15 MWe has turbine and producing from 0 to 20 tons per day of liquid hydrogen and from 0 to 20 MWt of process steam were considered. The annual revenue required to own and operate such plants was estimated to be significantly lower than the potential market value of the products. The results indicate a significant potential economic benefit to configuring IGCC systems to produce a clean fuel in addition to electricity and process steam in relatively small industrial applications.

Application of plasma electrolysis method for simultaneous phenol and Cr(VI) wastewater degradation using Na2SO4 electrolyte

NASA Astrophysics Data System (ADS)

Harianti, Aulia Rahmi; Saksono, Nelson

2017-11-01

Phenol and Cr (VI) are two types of wastewater known as dangerous and difficult to degrade. Through this study, phenol and Cr (VI) metal wastewater were degraded simultaneously using plasma electrolysis method by reactive species, •OH and H•. The variation of anode depth and position of plasma formation as independent variables correlated with yield of hydroxyl radical, percentage of phenol and Cr (VI) degradation, and specific energy. Within 30 minutes, phenol was degraded to 98.4% and Cr (VI) was degraded to 93.35% with 171.05 kJ/mmol in specific energy, and 174.53 ppm in COD. The optimum condition was obtained in anodic plasma and 1.5 cm in anode depth. The highest degradation percentage of phenol and Cr (VI) were 99.79% and 97.33% achieved during 180 minutes of plasma electrolysis process.

Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

NASA Technical Reports Server (NTRS)

Sibille, Laurent; Dominques, Jesus A.

2012-01-01

The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates thermal energy that should be able to maintain the molten phase (similar to electrolytic Hall-Heroult process for aluminum production). Self-heating via Joule heating offers many advantages: (1) The regolith itself is the crucible material, it protects the vessel walls (2) Simplifies the engineering of the reactor (3) Reduces power consumption (no external heating) (4) Extends the longevity of the reactor. Predictive modeling is a tool chosen to perform dimensional analysis of a self-heating reactor: (1) Multiphysics modeling (COMSOL) was selected for Joule heat generation and heat transfer (2) Objective is to identify critical dimensions for first reactor prototype.

21 CFR 886.4250 - Ophthalmic electrolysis unit.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to destroy...

21 CFR 886.4250 - Ophthalmic electrolysis unit.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to destroy...

21 CFR 886.4250 - Ophthalmic electrolysis unit.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to destroy...

21 CFR 886.4250 - Ophthalmic electrolysis unit.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to destroy...

21 CFR 886.4250 - Ophthalmic electrolysis unit.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to destroy...

[Water disinfection by the combined exposure to super-high frequency energy and available chlorine produced during water electrolysis].

PubMed

Klimarev, S I; Siniak, Iu E

2014-01-01

The article reports the results of studying the effects on polluted water of SHF-energy together with the residual free (active) chlorine as a by-product of electrolysis action on dissolved chlorine-containing salts. Purpose of the studies was to evaluate input of these elements to the water disinfection effect. The synergy was found to kill microorganisms without impacts on the physicochemical properties of processed water or nutrient medium; therefore, it can be used for water treatment, and cultivation of microorganisms in microbiology.

DETERMINATION OF MAXIMUM PERMISSIBLE LEAKAGE FROM THE HRT PROCESS STEAM SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gift, E.H.

1959-01-30

Calculations were made to determine the radiation hazard to HRT personnel as a result of leakage to the atmosphere from the process steam system in the event of a heat exchanger tube rupture. These calculations show that with the present four-minute delay before dumping approximately 1020 lb of fuel solution may be transferred to the steam system. The radiation hazard from fission products in the atomosphere will be negligble if the steam killer blower is operating. If this blower is not operatin. a natural convection loop will be set up in the steam killer which will have a condensing capacitymore » of 4 lb/min of steam at atmospheric pressure. In this latter case. the inhalation hazard will be negligible when the leak rate through the steam stop valves is less than 4lb/ min. (auth)« less

Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

NASA Astrophysics Data System (ADS)

Gong, Xuzhong; Ge, Lan; Wang, Zhi; Zhuang, Siyuan; Wang, Yuhua; Ren, Lihui; Wang, Mingyong

2016-02-01

Feasibility of high-sulfur bauxite electrolysis desulfurization was examined using the electrochemical characterization, XRD, DTA, and FTIR. The cyclic voltammetry curves indicated that bauxite water slurry (BWS) electrolysis in NaOH system was controlled by diffusion. Additionally, the desulfurization effect of NaCl as the electrolyte was significantly better than that of NaOH as an electrolyte. As the stirring rate increased, the desulfurization ratio in NaCl system was not increased obviously, while the desulfurization ratio in NaOH system increased significantly, indicating further that electrolysis desulfurization in NaOH solution was controlled by diffusion. According to XRD, DTA, and FTIR analysis, the characteristic peaks of sulfur-containing phase in bauxite after electrolysis weakened or disappeared, indicating that the pyrite in bauxite was removed from electrolysis. Finally, the electrolytic desulfurization technology of bauxite was proposed based on the characteristics of BWS electrolysis.

Electrolysis for corneal opacities in a young patient with superficial variant of granular corneal dystrophy (Reis-Bücklers corneal dystrophy).

PubMed

Kamoi, Mizuka; Mashima, Yukihiko; Kawashima, Motoko; Tsubota, Kazuo

2005-06-01

To report the efficacy of electrolysis as a treatment of corneal opacities in a young patient with the superficial variant of granular corneal dystrophy. Interventional case report. An 11-year-old boy presented with subepithelial opacities in both eyes. His visual acuity was 0.2 in the left eye; he received corneal electrolysis under topical anesthesia. The electrolysis, which required only 5 minutes, resulted in the disappearance of the subepithelial opacities. His visual acuity improved to 0.4 on the next day and was 1.0 eight months later. The corneal curvature and thickness were not altered by the electrolysis. Corneal electrolysis proved to be an effective treatment for subepithelial opacities, and we recommend electrolysis as an effective and simple treatment for young patients with SGCD.

Reforming of natural gas—hydrogen generation for small scale stationary fuel cell systems

NASA Astrophysics Data System (ADS)

Heinzel, A.; Vogel, B.; Hübner, P.

The reforming of natural gas to produce hydrogen for fuel cells is described, including the basic concepts (steam reforming or autothermal reforming) and the mechanisms of the chemical reactions. Experimental work has been done with a compact steam reformer, and a prototype of an experimental reactor for autothermal reforming was tested, both containing a Pt-catalyst on metallic substrate. Experimental results on the steam reforming system and a comparison of the steam reforming process with the autothermal process are given.

Solar process steam for a pharmaceutical company in Jordan

NASA Astrophysics Data System (ADS)

Berger, M.; Mokhtar, M.; Zahler, C.; Al-Najami, M. M. R.; Krüger, D.; Hennecke, K.

2016-05-01

This paper presents details of the recent installation of a linear Fresnel collector to provide saturated steam for process heat usage through Direct Steam Generation (DSG) for industrial use in the Jordanian pharmaceuticals manufacturing company RAM Pharma, where first solar steam has been provided in March 2015. This commercial DSG project also represents the first solar DSG plant in MENA. During sunshine, the system achieves a solar fraction of 100 %, and the conventional steam boiler is not needed. In the evening the fossil fired backup takes over automatically and replaces the solar collector in operation. Operational experience, details of the control strategy, and measurement data are presented in the paper.

Mathematical Modeling of Ammonia Electro-Oxidation on Polycrystalline Pt Deposited Electrodes

NASA Astrophysics Data System (ADS)

Diaz Aldana, Luis A.

The ammonia electrolysis process has been proposed as a feasible way for electrochemical generation of fuel grade hydrogen (H2). Ammonia is identified as one of the most suitable energy carriers due to its high hydrogen density, and its safe and efficient distribution chain. Moreover, the fact that this process can be applied even at low ammonia concentration feedstock opens its application to wastewater treatment along with H 2 co-generation. In the ammonia electrolysis process, ammonia is electro-oxidized in the anode side to produce N2 while H2 is evolved from water reduction in the cathode. A thermodynamic energy requirement of just five percent of the energy used in hydrogen production from water electrolysis is expected from ammonia electrolysis. However, the absence of a complete understanding of the reaction mechanism and kinetics involved in the ammonia electro-oxidation has not yet allowed the full commercialization of this process. For that reason, a kinetic model that can be trusted in the design and scale up of the ammonia electrolyzer needs to be developed. This research focused on the elucidation of the reaction mechanism and kinetic parameters for the ammonia electro-oxidation. The definition of the most relevant elementary reactions steps was obtained through the parallel analysis of experimental data and the development of a mathematical model of the ammonia electro-oxidation in a well defined hydrodynamic system, such as the rotating disk electrode (RDE). Ammonia electro-oxidation to N 2 as final product was concluded to be a slow surface confined process where parallel reactions leading to the deactivation of the catalyst are present. Through the development of this work it was possible to define a reaction mechanism and values for the kinetic parameters for ammonia electro-oxidation that allow an accurate representation of the experimental observations on a RDE system. Additionally, the validity of the reaction mechanism and kinetic parameters were supplemented by means of process scale up, performance evaluation, and hydrodynamic analysis in a flow cell electrolyzer. An adequate simulation of the flow electrolyzer performance was accomplished using the obtained kinetic parameters.

Electrolysis Performance Improvement and Validation Experiment

NASA Technical Reports Server (NTRS)

Schubert, Franz H.

1992-01-01

Viewgraphs on electrolysis performance improvement and validation experiment are presented. Topics covered include: water electrolysis: an ever increasing need/role for space missions; static feed electrolysis (SFE) technology: a concept developed for space applications; experiment objectives: why test in microgravity environment; and experiment description: approach, hardware description, test sequence and schedule.

Optimizing electrocoagulation process using experimental design for COD removal from unsanitary landfill leachate.

PubMed

Ogedey, Aysenur; Tanyol, Mehtap

2017-12-01

Leachate is the most difficult wastewater to be treated due to its complex content and high pollution release. For this reason, since it is not possible to be treated with a single process, a pre-treatment is needed. In the present study, a batch electrocoagulation reactor containing aluminum and iron electrodes was used to reduce chemical oxygen demand (COD) from landfill leachate (Tunceli, Turkey). Optimization of COD elimination was carried out with response surface methodology to describe the interaction effect of four main process independent parameters (current density, inter-electrode distance, pH and time of electrolysis). The optimum current density, inter-electrode distance, pH and time of electrolysis for maximum COD removal (43%) were found to be 19.42 mA/m 2 , 0.96 cm, 7.23 and 67.64 min, respectively. The results shown that the electrocoagulation process can be used as a pre-treatment step for leachate.

Transformation of deoxynivalenol and its acetylated derivatives in Chinese steamed bread making, as affected by pH, yeast, and steaming time.

PubMed

Wu, Li; Wang, Bujun

2016-07-01

We hereby report the transformation of deoxynivalenol (DON) and its acetylated derivatives (3-ADON and 15-ADON) by spiking targeted mycotoxins to Fusarium mycotoxin-free flour in the process of making Chinese steamed bread (CSB). The impacts of pH, yeast level, and steaming time on the transformation of 3-ADON to DON were investigated. DON, 3-ADON, and 15-ADON were analyzed by UPLC-MS/MS. Spiked DON was stable throughout the CSB making process. Spiked 3-ADON and 15-ADON were partially deacetylated and transformed to DON during kneading (54.1-60.0% and 59.3-77.5%, respectively), fermentation (64.0-76.9% and 78.2-91.6%, respectively), and steaming (47.2-52.7% and 52.4-61.9%, respectively). The ADONs level increased after steaming compared with their level in the previous step. The pH level and steaming duration significantly (P<0.05) affected the conversion of 3-ADON during the CSB making process. Briefly, alkaline conditions and short steaming times favored the deacetylation of 3-ADON. The level of yeast did not remarkably (P<0.05) alter the transformation between ADONs and DON. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mediated water electrolysis in biphasic systems.

PubMed

Scanlon, Micheál D; Peljo, Pekka; Rivier, Lucie; Vrubel, Heron; Girault, Hubert H

2017-08-30

The concept of efficient electrolysis by linking photoelectrochemical biphasic H 2 evolution and water oxidation processes in the cathodic and anodic compartments of an H-cell, respectively, is introduced. Overpotentials at the cathode and anode are minimised by incorporating light-driven elements into both biphasic reactions. The concepts viability is demonstrated by electrochemical H 2 production from water splitting utilising a polarised water-organic interface in the cathodic compartment of a prototype H-cell. At the cathode the reduction of decamethylferrocenium cations ([Cp 2 *Fe (III) ] + ) to neutral decamethylferrocene (Cp 2 *Fe (II) ) in 1,2-dichloroethane (DCE) solvent takes place at the solid electrode/oil interface. This electron transfer process induces the ion transfer of a proton across the immiscible water/oil interface to maintain electroneutrality in the oil phase. The oil-solubilised proton immediately reacts with Cp 2 *Fe (II) to form the corresponding hydride species, [Cp 2 *Fe (IV) (H)] + . Subsequently, [Cp 2 *Fe (IV) (H)] + spontaneously undergoes a chemical reaction in the oil phase to evolve hydrogen gas (H 2 ) and regenerate [Cp 2 *Fe (III) ] + , whereupon this catalytic Electrochemical, Chemical, Chemical (ECC') cycle is repeated. During biphasic electrolysis, the stability and recyclability of the [Cp 2 *Fe (III) ] + /Cp 2 *Fe (II) redox couple were confirmed by chronoamperometric measurements and, furthermore, the steady-state concentration of [Cp 2 *Fe (III) ] + monitored in situ by UV/vis spectroscopy. Post-biphasic electrolysis, the presence of H 2 in the headspace of the cathodic compartment was established by sampling with gas chromatography. The rate of the biphasic hydrogen evolution reaction (HER) was enhanced by redox electrocatalysis in the presence of floating catalytic molybdenum carbide (Mo 2 C) microparticles at the immiscible water/oil interface. The use of a superhydrophobic organic electrolyte salt was critical to ensure proton transfer from water to oil, and not anion transfer from oil to water, in order to maintain electroneutrality after electron transfer. The design, testing and successful optimisation of the operation of the biphasic electrolysis cell under dark conditions with Cp 2 *Fe (II) lays the foundation for the achievement of photo-induced biphasic water electrolysis at low overpotentials using another metallocene, decamethylrutheneocene (Cp 2 *Ru (II) ). Critically, Cp 2 *Ru (II) may be recycled at a potential more positive than that of proton reduction in DCE.

Investigation of DBS electro-oxidation reaction in the aqueous-organic solution of LiClO4.

PubMed

Darlewski, Witold; Popiel, Stanisław; Nalepa, Tomasz; Gromotowicz, Waldemar; Szewczyk, Rafał; Stankiewicz, Romuald

2010-03-15

A process of dibutyl sulphide (DBS) electro-oxidation using electrolysis and cyclic voltamperometry was investigated in water-methanol solution using different electrodes (platinum, boron doped diamond, graphite and glassy carbon). Obtained results indicate that the DBS electro-oxidation process is irreversible in voltamperometric conditions. It was shown that during DBS electrolytic oxidation on Pt, at the low anode potential (1.8 V), DBS was oxidized to sulphoxide and sulphone. Electrolysis at higher potential (up to 3.0 V) resulted in complete DBS oxidation and formation of various products, including: butyric acid, sulphuric acid, butanesulphinic acid, butanesulphonic acid, identified using gas chromatography (GC-AED) and mass spectrometry (GC-MS) methods. (c) 2009 Elsevier B.V. All rights reserved.

Preparation of Al-Ti Master Alloy by Electrochemical Recovery of Titanium-Reducing Slag in Molten Salts

NASA Astrophysics Data System (ADS)

Zhao, Kun; Wang, Yaowu; Feng, Naixiang

2018-02-01

An electrochemical method for the preparation of an Al-Ti master alloy in Al electrolysis melts of Na3AlF6-Al2O3-LiF at 980°C was investigated. The Ti-reducing slag (5.24 wt.% Ti in the Ti-reducing slag) was obtained from the aluminothermic reduction of Na2TiF6. The cold test (i.e., the aluminothermic reduction process without applying any voltages) result revealed the capability of the Al cathode to reduce the Ti slag, and the recovery rate could reach 45.8% at 980°C over 3.5 h with the addition of 10 wt.% Ti-reducing slag. In contrast, the recovery rate of Ti after electrolysis at 3.0 V could reach 99.2%. Thus, the electrochemical treatment for Ti-reducing slag is a cooperative process involving aluminothermic and electrochemical reduction reactions. Electrochemical analysis indicated that the Ti ions are reduced to metallic Ti according to Ti4+ → Ti3+ → Ti. An Al-Ti alloy layer could be prepared on the external surface of the Mo electrode after electrolysis with the addition of 12 wt.% Ti-reducing slag.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: comparison of electrode materials and electrode connection systems.

PubMed

Solak, Murat; Kiliç, Mehmet; Hüseyin, Yazici; Sencan, Aziz

2009-12-15

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m(2), and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m(2), respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

In-Space Propulsion, Logistics Reduction, and Evaluation of Steam Reformer Kinetics: Problems and Prospects

NASA Technical Reports Server (NTRS)

Jaworske, D. A.; Palaszewski, B. A.; Kulis, M. J.; Gokoglu, S. A.

2015-01-01

Human space missions generate waste materials. A 70-kg crewmember creates a waste stream of 1 kg per day, and a four-person crew on a deep space habitat for a 400+ day mission would create over 1600 kg of waste. Converted into methane, the carbon could be used as a fuel for propulsion or power. The NASA Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) project is investing in space resource utilization with an emphasis on repurposing logistics materials for useful purposes and has selected steam reforming among many different competitive processes as the preferred method for repurposing organic waste into methane. Already demonstrated at the relevant processing rate of 5.4 kg of waste per day, high temperature oxygenated steam consumes waste and produces carbon dioxide, carbon monoxide, and hydrogen which can then be converted into methane catalytically. However, the steam reforming process has not been studied in microgravity. Data are critically needed to understand the mechanisms that allow use of steam reforming in a reduced gravity environment. This paper reviews the relevant literature, identifies gravity-dependent mechanisms within the steam gasification process, and describes an innovative experiment to acquire the crucial kinetic information in a small-scale reactor specifically designed to operate within the requirements of a reduced gravity aircraft flight. The experiment will determine if the steam reformer process is mass-transport limited, and if so, what level of forced convection will be needed to obtain performance comparable to that in 1-g.

Disinfection of Cystoscopes by Subatmospheric Steam and Steam and Formaldehyde at 80°C

PubMed Central

Alder, V. G.; Gingell, J. C.; Mitchell, J. P.

1971-01-01

A new method of disinfection adapted for endoscopic instruments uses low temperature steam at 80°C or steam and formaldehyde at 80°C. The process has considerable advantages over existing methods and more closely approaches the ideal requirements. ImagesFIG. 3FIG. 4FIG. 5 PMID:5569551

Net energy ratio for the production of steam pretreated biomass-based pellets

DOE PAGES

Shahrukh, Hassan; Oyedun, Adetoyese Olajire; Kumar, Amit; ...

2015-06-21

In this study, a process model was developed to determine the net energy ratio (NER) for both regular and steam-pretreated pellet production from ligno-cellulosic biomass. NER is a ratio of the net energy output to the total net energy input from non-renewable energy source into the system. Scenarios were developed to measure the effect of temperature and level of steam pretreatment on the NER of both production processes. The NER for the base case at 6 kg h –1 is 1.29 and 5.0 for steam-pretreated and regular pellet production respectively. However, at the large scale NER would improve. The majormore » factor for NER is energy for steam and drying unit. The sensitivity analysis for the model shows that the optimum temperature for steam pretreatment is 200 °C with 50% pretreatment (Steam pretreating 50% feed stock, while the rest is undergoing regular pelletization). Uncertainty result for steam pretreated and regular pellet is 1.35 ± 0.09 and 4.52 ± 0.34 respectively.« less

Performance and economic assessments of a solid oxide fuel cell system with a two-step ethanol-steam-reforming process using CaO sorbent

NASA Astrophysics Data System (ADS)

Tippawan, Phanicha; Arpornwichanop, Amornchai

2016-02-01

The hydrogen production process is known to be important to a fuel cell system. In this study, a carbon-free hydrogen production process is proposed by using a two-step ethanol-steam-reforming procedure, which consists of ethanol dehydrogenation and steam reforming, as a fuel processor in the solid oxide fuel cell (SOFC) system. An addition of CaO in the reformer for CO2 capture is also considered to enhance the hydrogen production. The performance of the SOFC system is analyzed under thermally self-sufficient conditions in terms of the technical and economic aspects. The simulation results show that the two-step reforming process can be run in the operating window without carbon formation. The addition of CaO in the steam reformer, which runs at a steam-to-ethanol ratio of 5, temperature of 900 K and atmospheric pressure, minimizes the presence of CO2; 93% CO2 is removed from the steam-reforming environment. This factor causes an increase in the SOFC power density of 6.62%. Although the economic analysis shows that the proposed fuel processor provides a higher capital cost, it offers a reducing active area of the SOFC stack and the most favorable process economics in term of net cost saving.

Heat penetration attributes of milkfish (Chanos chanos) thermal processed in flexible pouches: a comparative study between steam application and water immersion.

PubMed

Adepoju, Mary A; Omitoyin, Bamidele O; Mohan, Chitradurga O; Zynudheen, Aliyam A

2017-05-01

The difference in the heating penetration characteristics of product processed in retort by steam-air application and water immersion was studied. Fresh milkfish ( Chanos chanos ) packed in dry pack and in oil medium, both in flexible pouches, was thermal processed to minimum F 0 value of 7.77 at 121.1°C. Heat penetration values were recorded for each minute of processing with the aid Ellab (TM 9608, Denmark) temperature recorder. Retort come up time to achieve 121.1°C was observed to be less in steam-air which invariably led to a lower Ball's process time (B) and the total process time (T) observed in steam-air as compared to water immersion. Obtained data were plotted on a semi-logarithmic paper with temperature deficit on x -axis against time on the y -axis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahrukh, Hassan; Oyedun, Adetoyese Olajire; Kumar, Amit

In this study, a process model was developed to determine the net energy ratio (NER) for both regular and steam-pretreated pellet production from ligno-cellulosic biomass. NER is a ratio of the net energy output to the total net energy input from non-renewable energy source into the system. Scenarios were developed to measure the effect of temperature and level of steam pretreatment on the NER of both production processes. The NER for the base case at 6 kg h –1 is 1.29 and 5.0 for steam-pretreated and regular pellet production respectively. However, at the large scale NER would improve. The majormore » factor for NER is energy for steam and drying unit. The sensitivity analysis for the model shows that the optimum temperature for steam pretreatment is 200 °C with 50% pretreatment (Steam pretreating 50% feed stock, while the rest is undergoing regular pelletization). Uncertainty result for steam pretreated and regular pellet is 1.35 ± 0.09 and 4.52 ± 0.34 respectively.« less

Evaluation of disinfective potential of reactivated free chlorine in pooled tap water by electrolysis.

PubMed

Nakajima, Norihito; Nakano, Takashi; Harada, Fumiue; Taniguchi, Hiromasa; Yokoyama, Isao; Hirose, Jun; Daikoku, Eriko; Sano, Kouichi

2004-05-01

Tap water is one of the causative factors of hospital infections. We examined the disinfective potential of electrolysis and mechanism of disinfection, and clarified the disinfective effect of electrolysis on tap water contaminated with bacteria, and discussed its clinical applications. Tap waters artificially contaminated with Pseudomonas aeruginosa, Escherichia coli, Legionella pneumophila, and Staphylococcus aureus could be sterilized by electrolysis at 20-30 mA for 5 min. A high-density suspension (10(6) CFU/ml) of a spore forming bacterium, Bacillus subtilis was not completely sterilized by electrolysis at 50 mA up to 30 min, but a low-density suspension (10(5) CFU/ml) was totally sterilized by electrolysis at 50 mA for 5 min. Electrolyzed P. aeruginosa changed morphologically, that is, there was bleb formation on the cell wall and irregular aggregation of cytoplasmic small granules. Moreover, cytoplasmic enzyme, nitrate reductase, was inactivated by the electrolysis. On the other hand, genomic DNA of the electrolyzed bacteria was not degenerated, therefore, their DNA polymerase activity was not completely inactivated. Consequently, the major agent in electrolysis for bactericidal action was considered to be free chlorine, and the possible bactericidal mechanism was by destruction of bacterial membranes, followed by the aggregation of peripheral cytoplasmic proteins. Electrolysis of tap water for both disinfecting contaminating bacteria and increasing the disinfectant capacity was considered effective with some limitations, particularly against high-density contamination by spore-forming bacteria. In clinical settings, electrolysis of tap water is considered effective to disinfect water for hand washing in operation theatres, and bathing water for immunocompromised hosts.

Production of Oxygen from Lunar Regolith using Molten Oxide Electrolysis

NASA Technical Reports Server (NTRS)

Sibille, Laurent; Sadoway, Donald R.; Sirk, Aislinn; Tripathy, Prabhat; Melendez, Orlando; Standish, Evan; Dominquez, Jesus A.; Stefanescu, Doru M.; Curreri, Peter A.; Poizeau, Sophie

2009-01-01

This slide presentation reviews the possible use of molten oxide electrolysis to extract oxygen from the Lunar Regolith. The presentation asserts that molten regolith electrolysis has advanced to be a useful method for production of oxygen and metals in situ on the Moon. The work has demonstrated an 8 hour batch of electrolysis at 5 amps using Iridium inert anodes.

Changes in Levels of Phenylethanoid Glycosides, Antioxidant Activity, and Other Quality Traits in Cistanche deserticola Slices by Steam Processing.

PubMed

Peng, Fang; Chen, Jun; Wang, Xia; Xu, Changqing; Liu, Tongning; Xu, Rong

2016-07-01

We investigated the effect of steaming time on Cistanche deserticola Y. C. MA slices by analyzing levels of bioactive compounds, antioxidant activity, and weight loss compared with fresh, directly oven-dried, and blanched samples. Fresh samples had extremely low levels of phenylethanoid glycosides and antioxidant activity. Lower levels of weight loss and higher amounts of soluble sugars, polysaccharides, and dilute ethanol-soluble extracts were found when the slices were steamed rather than blanched. Slices steamed for 5 and 7 min contained significantly (p<0.05) higher amounts of acteoside, isoacteoside, and 2'-acetylacteoside than directly oven-dried samples. However, soluble sugars and dilute ethanol-soluble extracts decreased gradually throughout the steaming process. The concentration of polysaccharides fluctuated during the steaming process. The steaming time had a consistent effect on antioxidant properties evaluated by oxygen radical absorbance capacity (ORAC), 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH) and ferric reducing antioxidant property (FRAP), showing a significant increase and reaching 108.62, 23.08, and 11.68 micromoles Trolox per mass of fresh slice (μmol TE/g FW), respectively. The present results suggest that fresh-cut C. deserticola can be subjected to approximately 5-7 min of steaming to improve phenylethanoid glycoside levels and antioxidant activity, while still preserving the amounts of soluble sugars, polysaccharides, and dilute ethanol-soluble extracts. These results would help to improve the production process for fresh-cut Chinese medicines, and increase the understanding of their associated health benefits.

The development of a non-cryogenic nitrogen/oxygen supply system. [using hydrazine/water electrolysis

NASA Technical Reports Server (NTRS)

Greenough, B. M.; Mahan, R. E.

1974-01-01

A hydrazine/water electrolysis process system module design was fabricated and tested to demonstrate component and module performance. This module is capable of providing both the metabolic oxygen for crew needs and the oxygen and nitrogen for spacecraft leak makeup. The component designs evolved through previous R and D efforts, and were fabricated and tested individually and then were assembled into a complete module which was successfully tested for 1000 hours to demonstrate integration of the individual components. A survey was made of hydrazine sensor technology and a cell math model was derived.

Magnesium Recycling of Partially Oxidized, Mixed Magnesium-Aluminum Scrap Through Combined Refining and Solid Oxide Membrane (SOM) Electrolysis Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, Xiaofei; Zink, Peter; Pal, Uday

2012-03-11

Pure magnesium (Mg) is recycled from 19g of partially oxidized 50.5wt.%Mg-Aluminum (Al) alloy. During the refining process, potentiodynamic scans (PDS) were performed to determine the electrorefining potential for magnesium. The PDS show that the electrorefining potential increases over time as the Mg content inside the Mg-Al scrap decreases. Up to 100% percent of magnesium is refined from the Mg-Al scrap by a novel refining process of dissolving magnesium and its oxide into a flux followed by vapor phase removal of dissolved magnesium and subsequently condensing the magnesium vapors in a separate condenser. The solid oxide membrane (SOM) electrolysis process ismore » employed in the refining system to enable additional recycling of magnesium from magnesium oxide (MgO) in the partially oxidized Mg-Al scrap. The combination of the refining and SOM processes yields 7.4g of pure magnesium; could not collect and weigh all of the magnesium recovered.« less

Experimental Demonstration of the Molten Oxide Electrolysis Method for Oxygen and Iron Production from Simulated Lunar Materials

NASA Technical Reports Server (NTRS)

Curreri, P. A.; Ethridge, E.; Hudson, S.; Sen, S.

2006-01-01

This paper presents the results of a Marshall Space Flight Center funded effort to conduct an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis (MOE) process to produce oxygen and metal from lunar resources to support human exploration of space. Oxygen extracted from lunar materials can be used for life support and propellant, and silicon and metallic elements produced can be used for in situ fabrication of thin-film solar cells for power production. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis, MOE, is chosen for extraction, since the electron is the most practical reducing agent. MOE was also chosen for following reasons. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. In the experiments reported here, melts containing iron oxide were electrolyzed in a low temperature supporting oxide electrolyte (developed by D. Sadoway, MIT).

An innovative application of stable isotopes (δ2H and δ18O) for tracing pollutant plumes in groundwater.

PubMed

Negrel, Philippe; Ollivier, Patrick; Flehoc, Christine; Hube, Daniel

2017-02-01

The identification of the sources of contaminants present in groundwater at industrial sites is primordial to address environmental and industrial issues. However, available tools are often inadequate or expensive. Here, we present the data of stable isotopes (δ 18 O and δ 2 H) of the water molecule at an industrial site where electrochemistry plant occurs impacting the groundwater quality. High ClO 3 and ClO 4 contents and 2 H enrichment have been measured in groundwater. Recharge of aquifer relates to infiltration of rainwater and by subsurface inflow. On-site, industrial products are generated by electrolysis. We show that the electrolysis process leads to a large 2 H enrichment (+425‰) in solutions. In the absence of hydrothermal water input containing H 2 S, we demonstrate that the relationship between δ 18 O and δ 2 H can be easily used in a way to trace the origin of the ClO 3 and ClO 4 in groundwater. Isotopes evidenced first a leakage from end-product storage tanks or during the production process itself. Then, an accumulation and release of ClO 3 and ClO 4 from soil is demonstrated. Our study successfully shows that stable isotopes are a powerful and low cost tool for tracing pollutant plumes in an industrial context using electrolysis process. Copyright © 2016 Elsevier B.V. All rights reserved.

Multi-purpose hydrogen isotopes separation plant design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boniface, H.A.; Gnanapragasam, N.V.; Ryland, D.K.

2015-03-15

There is a potential interest at AECL's Chalk River Laboratories to remove tritium from moderately tritiated light water and to reclaim tritiated, downgraded heavy water. With only a few limitations, a single CECE (Combined Electrolysis and Catalytic Exchange) process configuration can be designed to remove tritium from heavy water or light water and upgrade heavy water. Such a design would have some restrictions on the nature of the feed-stock and tritium product, but could produce essentially tritium-free light or heavy water that is chemically pure. The extracted tritium is produced as a small quantity of tritiated heavy water. The overallmore » plant capacity is fixed by the total amount of electrolysis and volume of catalyst. In this proposal, with 60 kA of electrolysis a throughput of 15 kg*h{sup -1} light water for detritiation, about 4 kg*h{sup -1} of heavy water for detritiation and about 27 kg*h{sup -1} of 98% heavy water for upgrading can be processed. Such a plant requires about 1,000 liters of AECL isotope exchange catalyst. The general design features and details of this multi-purpose CECE process are described in this paper, based on some practical choices of design criteria. In addition, we outline the small differences that must be accommodated and some compromises that must be made to make the plant capable of such flexible operation. (authors)« less

STEAM Enacted: A Case Study of a Middle School Teacher Implementing STEAM Instructional Practices

ERIC Educational Resources Information Center

Herro, Danielle; Quigley, Cassie

2016-01-01

This paper examines the implementation practices of a 6th grade middle school teacher enacting STEAM (science, technology, engineering, art and math) teaching in his classroom after participating in a 45-hour STEAM professional development. Case study is used to detail the process, successes, and challenges. Project-based learning, technology…

Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

NASA Astrophysics Data System (ADS)

Semelsberger, Troy A.; Borup, Rodney L.

The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

Downhole steam generator using low-pressure fuel and air supply

DOEpatents

Fox, R.L.

1981-01-07

For tertiary oil recovery, an apparatus for downhole steam generation is designed in which water is not injected directly onto the flame in the combustor, the combustion process is isolated from the reservoir pressure, the fuel and oxidant are supplied to the combustor at relatively low pressures, and the hot exhaust gases is prevented from entering the earth formation but is used to preheat the fuel and oxidant and water. The combustion process is isolated from the steam generation process. (DLC)

Comparison of conventional vs. modular hydrogen refueling stations and on-site production vs. delivery.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hecht, Ethan S.; Pratt, Joseph William

To meet the needs of public and private stakeholders involved in the development, construction, and operation of hydrogen fueling stations needed to support the widespread roll-out of hydrogen fuel cell electric vehicles, this work presents publicly available station templates and analyses. These ‘Reference Stations’ help reduce the cost and speed the deployment of hydrogen stations by providing a common baseline with which to start a design, enable quick assessment of potential sites for a hydrogen station, identify contributors to poor economics, and suggest areas of research. This work presents layouts, bills of materials, piping and instrumentation diagrams, and detailed analysesmore » of five new station designs. In the near term, delivered hydrogen results in a lower cost of hydrogen compared to on-site production via steam methane reforming or electrolysis, although the on-site production methods have other advantages. Modular station concepts including on-site production can reduce lot sizes from conventional assemble-on-site stations.« less

Dual Rate Adaptive Control for an Industrial Heat Supply Process Using Signal Compensation Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chai, Tianyou; Jia, Yao; Wang, Hong

The industrial heat supply process (HSP) is a highly nonlinear cascaded process which uses a steam valve opening as its control input, the steam flow-rate as its inner loop output and the supply water temperature as its outer loop output. The relationship between the heat exchange rate and the model parameters, such as steam density, entropy, and fouling correction factor and heat exchange efficiency are unknown and nonlinear. Moreover, these model parameters vary in line with steam pressure, ambient temperature and the residuals caused by the quality variations of the circulation water. When the steam pressure and the ambient temperaturemore » are of high values and are subjected to frequent external random disturbances, the supply water temperature and the steam flow-rate would interact with each other and fluctuate a lot. This is also true when the process exhibits unknown characteristic variations of the process dynamics caused by the unexpected changes of the heat exchange residuals. As a result, it is difficult to control the supply water temperature and the rates of changes of steam flow-rate well inside their targeted ranges. In this paper, a novel compensation signal based dual rate adaptive controller is developed by representing the unknown variations of dynamics as unmodeled dynamics. In the proposed controller design, such a compensation signal is constructed and added onto the control signal obtained from the linear deterministic model based feedback control design. Such a compensation signal aims at eliminating the unmodeled dynamics and the rate of changes of the currently sample unmodeled dynamics. A successful industrial application is carried out, where it has been shown that both the supply water temperature and the rate of the changes of the steam flow-rate can be controlled well inside their targeted ranges when the process is subjected to unknown variations of its dynamics.« less

DATA QUALITY OBJECTIVES FOR SELECTING WASTE SAMPLES FOR THE BENCH STEAM REFORMER TEST

DOE Office of Scientific and Technical Information (OSTI.GOV)

BANNING DL

2010-08-03

This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Fluid Bed Steam Reformer testing. The type, quantity and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluid bed steam reformer (FBSR). A determination of the adequacy of the FBSR process to treat Hanford tank waste is required.more » The initial step in determining the adequacy of the FBSR process is to select archived waste samples from the 222-S Laboratory that will be used to test the FBSR process. Analyses of the selected samples will be required to confirm the samples meet the testing criteria.« less

Study on loading coefficient in steam explosion process of corn stalk.

PubMed

Sui, Wenjie; Chen, Hongzhang

2015-03-01

The object of this work was to evaluate the effect of loading coefficient on steam explosion process and efficacy of corn stalk. Loading coefficient's relation with loading pattern and material property was first revealed, then its effect on transfer process and pretreatment efficacy of steam explosion was assessed by established models and enzymatic hydrolysis tests, respectively, in order to propose its optimization strategy for improving the process economy. Results showed that loading coefficient was mainly determined by loading pattern, moisture content and chip size. Both compact loading pattern and low moisture content improved the energy efficiency of steam explosion pretreatment and overall sugar yield of pretreated materials, indicating that they are desirable to improve the process economy. Pretreatment of small chip size showed opposite effects in pretreatment energy efficiency and enzymatic hydrolysis performance, thus its optimization should be balanced in investigated aspects according to further techno-economical evaluation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pretreatment efficiency and structural characterization of rice straw by an integrated process of dilute-acid and steam explosion for bioethanol production.

PubMed

Chen, Wen-Hua; Pen, Ben-Li; Yu, Ching-Tsung; Hwang, Wen-Song

2011-02-01

The combined pretreatment of rice straw using dilute-acid and steam explosion followed by enzymatic hydrolysis was investigated and compared with acid-catalyzed steam explosion pretreatment. In addition to measuring the chemical composition, including glucan, xylan and lignin content, changes in rice straw features after pretreatment were investigated in terms of the straw's physical properties. These properties included crystallinity, surface area, mean particle size and scanning electron microscopy imagery. The effect of acid concentration on the acid-catalyzed steam explosion was studied in a range between 1% and 15% acid at 180°C for 2 min. We also investigated the influence of the residence time of the steam explosion in the combined pretreatment and the optimum conditions for the dilute-acid hydrolysis step in order to develop an integrated process for the dilute-acid and steam explosion. The optimum operational conditions for the first dilute-acid hydrolysis step were determined to be 165°C for 2 min with 2% H(2)SO(4) and for the second steam explosion step was to be carried out at 180°C for 20 min; this gave the most favorable combination in terms of an integrated process. We found that rice straw pretreated by the dilute-acid/steam explosions had a higher xylose yield, a lower level of inhibitor in the hydrolysate and a greater degree of enzymatic hydrolysis; this resulted in a 1.5-fold increase in the overall sugar yield when compared to the acid-catalyzed steam explosion. Copyright © 2010 Elsevier Ltd. All rights reserved.

Studying Activity Series of Metals.

ERIC Educational Resources Information Center

Hoon, Tien-Ghun; And Others

1995-01-01

Presents teaching strategies that illustrate the linking together of numerous chemical concepts involving the activity of metals (quantitative analysis, corrosion, and electrolysis) through the use of deep-level processing strategies. Concludes that making explicit links in the process of teaching chemistry can lead effectively to meaningful…

Feasibility Study of Seawater Electrolysis for Photovoltaic/Fuel Cell Hybrid Power System for the Coastal Areas in Thailand

NASA Astrophysics Data System (ADS)

Srisiriwat, A.; Pirom, W.

2017-10-01

Solar photovoltaic cell and fuel cell are the practicable options to realize as a possible hybrid power system because the power of the sun cannot be utilized at night or cloudy days but hydrogen has been found as an ideal energy carrier for being transportable, storable, and converting energy though fuel cell. Hydrogen storage is chosen for its ability to obtain a clean energy option. Electrolysis, which is the simplest process to produce hydrogen, can be powered by the dc voltage from the photovoltaic cell instead of using the battery as power supply. This paper concentrates on a feasibility study of seawater electrolysis using photovoltaic power integrated fuel cell system for the coastal cities in Thailand. The proposed system composed of photovoltaic arrays, seawater electrolyzer and fuel cell is presented when the 10-kW of fuel cell electrical power is considered. The feasibility study of hydrogen production and energy analysis of this proposed system is also evaluated.

Adsorption of oils, heavy metals and dyes by recovered carbon powder from spent pot liner of aluminum smelter plant.

PubMed

Mazumder, B; Devi, Sasmita Rani

2008-07-01

Aluminum smelter plants employ Hall-Heroult electrolysis cells for electrolysis of molten cryolite to recover aluminum metal by electrolysis. These cells use carbon cathode blocks as a lining material inside. At the end of service life of the cells, pot lines are discarded and new carbon blocks are laid for fresh charging. These used carbon cathode blocks, known as spent pot liners, are heavily infested with toxic elements such as fluoride, cyanide, alkali, etc. Therefore, their disposal in open field poses great environmental risk. A simple process has been developed for decontamination of these spent pot liners and to recover its carbon value. The experiments indicated that this carbon, in the form of fine powder (around 20 micron in size) can absorb toxic elements like heavy metals, dyes, oils, etc. to a great extent and thus can be used for mitigating environmental pollution occuring due to various toxic wastes.

Solid-State Water Electrolysis with an Alkaline Membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leng, YJ; Chen, G; Mendoza, AJ

2012-06-06

We report high-performance, durable alkaline membrane water electrolysis in a solid-state cell. An anion exchange membrane (AEM) and catalyst layer ionomer for hydroxide ion conduction were used without the addition of liquid electrolyte. At 50 degrees C, an AEM electrolysis cell using iridium oxide as the anode catalyst and Pt black as the cathode catalyst exhibited a current density of 399 mA/cm(2) at 1.80 V. We found that the durability of the AEM-based electrolysis cell could be improved by incorporating a highly durable ionomer in the catalyst layer and optimizing the water feed configuration. We demonstrated an AEM-based electrolysis cellmore » with a lifetime of > 535 h. These first-time results of water electrolysis in a solid-state membrane cell are promising for low-cost, scalable hydrogen production.« less

Combined uranous nitrate production consisting of undivided electrolytic cell and divided electrolytic cell (Electrolysis → Electrolytic cell)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Zhongwei; Yan, Taihong; Zheng, Weifang

2013-07-01

The electrochemical reduction of uranyl nitrate is a green, mild way to make uranous ions. Undivided electrolyzers whose maintenance is less but their conversion ratio and current efficiency are low, have been chosen. However, at the beginning of undivided electrolysis, high current efficiency can also be maintained. Divided electrolyzers' conversion ratio and current efficiency is much higher because the re-oxidation of uranous on anode is avoided, but their maintenance costs are more, because in radioactive environment the membrane has to be changed after several operations. In this paper, a combined method of uranous production is proposed which consists of 2more » stages: undivided electrolysis (early stage) and divided electrolysis (late stage) to benefit from the advantages of both electrolysis modes. The performance of the combined method was tested. The results show that in combined mode, after 200 min long electrolysis (80 min undivided electrolysis and 120 min divided electrolysis), U(IV) yield can achieve 92.3% (500 ml feed, U 199 g/l, 72 cm{sup 2} cathode, 120 mA/cm{sup 2}). Compared with divided mode, about 1/3 working time in divided electrolyzer is reduced to achieve the same U(IV) yield. If 120 min long undivided electrolysis was taken, more than 1/2 working time can be reduced in divided electrolyzer, which means that about half of the maintenance cost can also be reduced. (authors)« less

Utilisation of energy from digester gas and sludge incineration at Hamburg's Köhlbrandhöft WWTP.

PubMed

Thierbach, R D; Hanssen, H

2002-01-01

At Hamburg's Köhlbrandhöft WWTP the demand for external energy supply is minimised by state of the art sludge treatment. The sludge is subjected to thickening, anaerobic digestion, dewatering, drying and incineration. The digester gas is used in a combined gas and steam turbine process. The sludge incineration also produces steam, which is also used in the steam turbine that follows the gas turbine. The turbines produce electricity, partially expanded steam is used for the sludge drying process. Heat from the condensation of vapours from sludge drying is used to heat the anaerobic digesters. The overall process requires no external heat or fuel and produces 60% of the WWTP's electricity demand.

Engineering and economic analysis for the utilization of geothermal fluids in a cane sugar processing plant. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humme, J.T.; Tanaka, M.T.; Yokota, M.H.

1979-07-01

The purpose of this study was to determine the feasibility of geothermal resource utilization at the Puna Sugar Company cane sugar processing plant, located in Keaau, Hawaii. A proposed well site area was selected based on data from surface exploratory surveys. The liquid dominated well flow enters a binary thermal arrangement, which results in an acceptable quality steam for process use. Hydrogen sulfide in the well gases is incinerated, leaving sulfur dioxide in the waste gases. The sulfur dioxide in turn is recovered and used in the cane juice processing at the sugar factory. The clean geothermal steam from themore » binary system can be used directly for process requirements. It replaces steam generated by the firing of the waste fibrous product from cane sugar processing. The waste product, called bagasse, has a number of alternative uses, but an evaluation clearly indicated it should continue to be employed for steam generation. This steam, no longer required for process demands, can be directed to increased electric power generation. Revenues gained by the sale of this power to the utility, in addition to other savings developed through the utilization of geothermal energy, can offset the costs associated with hydrothermal utilization.« less

Steam drum design for direct steam generation

NASA Astrophysics Data System (ADS)

Willwerth, Lisa; Müller, Svenja; Krüger, Joachim; Succo, Manuel; Feldhoff, Jan Fabian; Tiedemann, Jörg; Pandian, Yuvaraj; Krüger, Dirk; Hennecke, Klaus

2017-06-01

For the direct steam generation in solar fields, the recirculation concept has been demonstrated in several installations. Water masses in the solar field vary during transient phases, such as passing clouds. The volume of the steam drum can serve as a buffer during such transients by taking in excess water and providing water storage. The saturated steam mass flow to the superheating section or the consumer can be maintained almost constant during short transients; therefore the steam drum plays a key role for constant steam supply. Its buffer effect depends on the right sizing of the steam drum for the prevailing situations. Due to missing experiences, steam drums have been sized under conservative assumptions and are thereby usually oversized. With this paper, experiences on the steam drum of the 5 MWel TSE1 power plant are discussed for optimized future plant design. The results are also of relevance for process heat installations, in which saturated steam is produced by the solar field.

Low-Energy Catalytic Electrolysis for Simultaneous Hydrogen Evolution and Lignin Depolymerization.

PubMed

Du, Xu; Liu, Wei; Zhang, Zhe; Mulyadi, Arie; Brittain, Alex; Gong, Jian; Deng, Yulin

2017-03-09

Here, a new proton-exchange-membrane electrolysis is presented, in which lignin was used as the hydrogen source at the anode for hydrogen production. Either polyoxometalate (POM) or FeCl 3 was used as the catalyst and charge-transfer agent at the anode. Over 90 % Faraday efficiency was achieved. In a thermal-insulation reactor, the heat energy could be maintained at a very low level for continuous operation. Compared to the best alkaline-water electrolysis reported in literature, the electrical-energy consumption could be 40 % lower with lignin electrolysis. At the anode, the Kraft lignin (KL) was oxidized to aromatic chemicals by POM or FeCl 3 , and reduced POM or Fe ions were regenerated during the electrolysis. Structure analysis of the residual KL indicated a reduction of the amount of hydroxyl groups and the cleavage of ether bonds. The results suggest that POM- or FeCl 3 -mediated electrolysis can significantly reduce the electrolysis energy consumption in hydrogen production and, simultaneously, depolymerize lignin to low-molecular-weight value-added aromatic chemicals. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Removal of pigments from molasses wastewater by combining micro-electrolysis with biological treatment method.

PubMed

Chen, Ben; Tian, Xiaofei; Yu, Lian; Wu, Zhenqiang

2016-12-01

Pigments in molasses wastewater (MWW) effluent, such as melanoidins, were considered as kinds of the most recalcitrant and hazardous colorant contaminants to the environment. In this study, de-coloring the MWW by a synergistic combination of micro-electrolysis with bio-treatment was performed. Aiming to a high de-colorization yield, levels of nutrition source supplies, MWW dilution ratio, and micro-electrolysis reaction time were optimized accordingly. For a diluted (50 %, v/v) MWW, an maximum overall de-colorization yield (97.1 ± 0.5 %, for absorbance at 475 nm) was achieved through the bio-electrolysis treatment. In electrolysis bio-treatment, the positive effect of micro-electrolysis was also revealed by a promoted growth of fungal biomass as well as activities of ligninolytic enzymes. Activities of lignin peroxidase, manganese peroxidase, and laccase were promoted by 111.2, 103.9, and 7.7 %, respectively. This study also implied that the bio-treatment and the micro-electrolysis had different efficiencies on removal of pigments with distinct polarities.

Constructing COMSOL Models of a Bacteriological Fuel Cell

NASA Technical Reports Server (NTRS)

Coker, Robert; Mansell, James

2012-01-01

We show very initial work on a specific bioelectrochemical system (BES), a bacteriologically driven 'fuel cell' (BFS), that is intended to process waste products, such as CO2 and brine. (1) Processing is the priority, not power generation (2) Really a Microbial Electrolysis Cell (MEC)

Thermodynamic Analysis of the Use a Chemical Heat Pump to Link a Supercritical Water-Cooled Nuclear Reactor and a Thermochemical Water-Splitting Cycle for Hydrogen Production

NASA Astrophysics Data System (ADS)

Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.; Pioro, Igor

Increases in the power generation efficiency of nuclear power plants (NPPs) are mainly limited by the permissible temperatures in nuclear reactors and the corresponding temperatures and pressures of the coolants in reactors. Coolant parameters are limited by the corrosion rates of materials and nuclear-reactor safety constraints. The advanced construction materials for the next generation of CANDU reactors, which employ supercritical water (SCW) as a coolant and heat carrier, permit improved “steam” parameters (outlet temperatures up to 625°C and pressures of about 25 MPa). An increase in the temperature of steam allows it to be utilized in thermochemical water splitting cycles to produce hydrogen. These methods are considered by many to be among the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require an intensive heat supply at temperatures higher than 550-600°C. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump, which increases the temperature of the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. Here, a high-temperature chemical heat pump, which employs the reversible catalytic methane conversion reaction, is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with the second steam cycle of a SCW nuclear power generation plant on one side and a thermochemical water splitting cycle on the other, increases the temperature of the “nuclear” heat and, consequently, the intensity of heat transfer into the water splitting cycle. A comparative preliminary thermodynamic analysis is conducted of the combined system comprising a SCW nuclear power generation plant and a chemical heat pump, which provides high-temperature heat to a thermochemical water splitting cycle for hydrogen production. It is concluded that the proposed chemical heat pump permits the utilization efficiency of nuclear energy to be improved by at least 2% without jeopardizing nuclear reactor safety. Based on this analysis, further research appears to be merited on the proposed advanced design of a nuclear power generation plant combined with a chemical heat pump, and implementation in appropriate applications seems worthwhile.

A Small-Scale and Low-Cost Apparatus for the Electrolysis of Water

ERIC Educational Resources Information Center

Eggeen, Per-Odd; Kvittingen, Lise

2004-01-01

The construction of two simple, inexpensive apparatuses that clearly show the electrolysis of water are described. Traditionally the electrolysis of water is conducted in a Hofmann apparatus which is expensive and fragile.

Electrolysis Propulsion for Spacecraft Applications

NASA Technical Reports Server (NTRS)

deGroot, Wim A.; Arrington, Lynn A.; McElroy, James F.; Mitlitsky, Fred; Weisberg, Andrew H.; Carter, Preston H., II; Myers, Blake; Reed, Brian D.

1997-01-01

Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined.

Partial oxidation of methane (POM) assisted solid oxide co-electrolysis

DOEpatents

Chen, Fanglin; Wang, Yao

2017-02-21

Methods for simultaneous syngas generation by opposite sides of a solid oxide co-electrolysis cell are provided. The method can comprise exposing a cathode side of the solid oxide co-electrolysis cell to a cathode-side feed stream; supplying electricity to the solid oxide co-electrolysis cell such that the cathode side produces a product stream comprising hydrogen gas and carbon monoxide gas while supplying oxygen ions to an anode side of the solid oxide co-electrolysis cell; and exposing the anode side of the solid oxide co-electrolysis cell to an anode-side feed stream. The cathode-side feed stream comprises water and carbon dioxide, and the anode-side feed stream comprises methane gas such that the methane gas reacts with the oxygen ions to produce hydrogen and carbon monoxide. The cathode-side feed stream can further comprise nitrogen, hydrogen, or a mixture thereof.

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU-Concepts

NASA Technical Reports Server (NTRS)

LeVan, M. Douglas; Finn, John E.; Sridhar, K. R.

2000-01-01

Solid oxide electrolyzers, such as electrolysis cells utilizing yttria-stabilized zirconia, can produce oxygen from Mars atmospheric carbon dioxide and reject carbon monoxide and unreacted carbon dioxide in a separate stream. The oxygen-production process has been shown to be far more efficient if the high-pressure, unreacted carbon dioxide can be separated and recycled back into the feed stream. Additionally, the mass of the adsorption compressor can be reduced. Also, the carbon monoxide by-product is a valuable fuel for space exploration and habitation, with applications from fuel cells to production of hydrocarbons and plastics. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU. Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, respectively. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU, Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, Research needs for the design shown are as follows: (1) The best adsorbent for the process must be determined. (2) Adsorption isotherms must be measured, both for pure components and mixtures. (3) Mathematical modeling must be performed to provide a solid framework for design. (4) The separation system must be constructed and tested. (5) System integration must be studied.

Reactive oxygen and iron species monitoring to investigate the electro-Fenton performances. Impact of the electrochemical process on the biodegradability of metronidazole and its by-products.

PubMed

Aboudalle, Arwa; Fourcade, Florence; Assadi, Aymen Amin; Domergue, Lionel; Djelal, Hayet; Lendormi, Thomas; Taha, Samir; Amrane, Abdeltif

2018-05-01

In this study, the monitoring of reactive oxygen species and the regeneration of the ferrous ions catalyst were performed during electro-Fenton (EF) process to highlight the influence of operating parameters. The removal of metronidazole (MTZ) was implemented in an electrochemical mono-compartment batch reactor under various ranges of current densities, initial MTZ and ferrous ions concentrations, and pH values. It was found that under 0.07 mA cm -2 , 0.1 mM of ferrous ions and pH = 3, the efficiency of 100 mg L -1 MTZ degradation and mineralization were 100% within 20 min and 40% within 135 min of electrolysis, respectively. The highest hydrogen peroxide and hydroxyl radical concentrations, 1.4 mM and 2.28 mM respectively, were obtained at 60 min electrolysis at 0.07 mA cm -2 . Improvement of the biodegradability was reached from 60 min of electrolysis with a BOD 5 /COD ratio above 0.4, which was reinforced by a respirometric study, that supports the feasibility of coupling electro-Fenton and biological treatment for the metronidazole removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Degradation of enoxacin antibiotic by the electro-Fenton process: Optimization, biodegradability improvement and degradation mechanism.

PubMed

Annabi, Cyrine; Fourcade, Florence; Soutrel, Isabelle; Geneste, Florence; Floner, Didier; Bellakhal, Nizar; Amrane, Abdeltif

2016-01-01

This study aims to investigate the effectiveness of the electro-Fenton process on the removal of a second generation of fluoroquinolone, enoxacin. The electrochemical reactor involved a carbon-felt cathode and a platinum anode. The influence of some experimental parameters, namely the initial enoxacin concentration, the applied current intensity and the Fe(II) amount, was examined. The degradation of the target molecule was accompanied by an increase of the biodegradability, assessed from the BOD5 on COD ratio, which increased from 0 before treatment until 0.5 after 180 min of electrolysis at 50 mg L(-1) initial enoxacin concentration, 0.2 mmol L(-1) Fe(II) concentration and 300 mA applied current intensity. TOC and COD time-courses were also evaluated during electrolysis and reached maximum residual yields of 54% and 43% after 120 min of treatment, respectively. Moreover, a simultaneous generation of inorganic ions (fluorides, ammonium and nitrates) were observed and 3 short chain carboxylic acids (formic, acetic and oxalic acids) were identified and monitored during 180 min of electrolysis. By-products were identified according to UPLC-MS/MS results and a degradation pathway was proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Equations for calculating the properties of dissociated steam

NASA Astrophysics Data System (ADS)

Aminov, R. Z.; Gudym, A. A.

2017-08-01

The equations of state for dissociated steam have been developed in the temperature and pressure ranges of 1250-2300 K and 0.01-10.00 MPa for calculating thermodynamic processes in thermal power units operating on high-temperature steam. These equations are based on the property tables for dissociated steam derived at a reference temperature of 0 K. It is assumed that the initial substance is steam, the dissociation of which—in accordance with the most likely chemical reactions—results in formation of molecules of hydrogen, oxygen, steam, hydroxyl, and atoms of oxygen and hydrogen. Differential thermodynamic correlations, considering a change in the chemical potential and the composition of the mixture, during the steam dissociation are used. A reference temperature of 0.01°C used in the calculation of parameters of nondissociated steam has been adopted to predict processes in thermal power units without matching the reference temperatures and to account for transformation of dissociated steam into its usual form for which there is the international system of equations with the water triple point of 0.01°C taken as the reference. In the investigated region, the deviation of dissociated steam properties from those of nondissociated steam, which increases with decreasing the pressure or increasing the temperature, was determined. For a pressure of 0.02 MPa and a temperature of 2200 K, these deviations are 512 kJ/kg for the enthalpy, 0.2574 kJ/(kg K) for the entropy, and 3.431 kJ/(kg K) for the heat capacity at constant pressure. The maximum deviation of the dissociated steam properties calculated by the developed equations from the handbook values that these equations are based on does not exceed 0.03-0.05%.

Dynamic underground stripping: steam and electric heating for in situ decontamination of soils and groundwater

DOEpatents

Daily, W.D.; Ramirez, A.L.; Newmark, R.L.; Udell, K.; Buetnner, H.M.; Aines, R.D.

1995-09-12

A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary. Geophysical imaging methods can be used to map the boundary between the hot, dry, contamination-free underground zone and the cool, damp surrounding areas to help monitor the dynamic stripping process. 4 figs.

Dynamic underground stripping: steam and electric heating for in situ decontamination of soils and groundwater

DOEpatents

Daily, William D.; Ramirez, Abelardo L.; Newmark, Robin L.; Udell, Kent; Buetnner, Harley M.; Aines, Roger D.

1995-01-01

A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary. Geophysical imaging methods can be used to map the boundary between the hot, dry, contamination-free underground zone and the cool, damp surrounding areas to help monitor the dynamic stripping process.

Results of Steam-Water-Oxygen Treatment of the Inside of Heating Surfaces in Heat-Recovery Steam Generators of the PGU-800 Power Unit at the Perm' District Thermal Power Station

NASA Astrophysics Data System (ADS)

Ovechkina, O. V.; Zhuravlev, L. S.; Drozdov, A. A.; Solomeina, S. V.

2018-05-01

Prestarting, postinstallation steam-water-oxygen treatment (SWOT) of the natural circulation/steam reheat heat-recovery steam generators (HRSG) manufactured by OAO Krasny Kotelshchik was performed at the PGU-800 power unit of the Perm District Thermal Power Station (GRES). Prior to SWOT, steam-oxygen cleaning, passivation, and preservation of gas condensate heaters (GCH) of HRSGs were performed for 10 h using 1.3MPa/260°C/70 t/h external steam. After that, test specimens were cut out that demonstrated high strength of the passivating film. SWOT of the inside of the heating surfaces was carried out during no-load operation of the gas turbine unit with an exhaust temperature of 280-300°C at the HRSG inlet. The steam turbine was shutdown, and the generated steam was discharged into the atmosphere. Oxygen was metered into the discharge pipeline of the electricity-driven feed pumps and downcomers of the evaporators. The behavior of the concentration by weight of iron compounds and the results of investigation of cutout specimens by the drop or potentiometric method indicate that the steam-water-oxygen process makes it possible to remove corrosion products and reduce the time required to put a boiler into operation. Unlike other processes, SWOT does not require metal-intensive cleaning systems, temporary metering stations, and structures for collection of the waste solution.

Enhancing the efficiency of zero valent iron by electrolysis: Performance and reaction mechanism.

PubMed

Xiong, Zhaokun; Lai, Bo; Yang, Ping

2018-03-01

Electrolysis was applied to enhance the efficiency of micron-size zero valent iron (mFe 0 ) and thereby promote p-nitrophenol (PNP) removal. The rate of PNP removal by mFe 0 with electrolysis was determined in cylindrical electrolysis reactor that employed annular aluminum plate cathode as a function of experimental factors, including initial pH, mFe 0 dosage and current density. The rate constants of PNP removal by Ele-mFe 0 were 1.72-144.50-fold greater than those by pristine mFe 0 under various tested conditions. The electrolysis-induced improvement could be primarily ascribed to stimulated mFe 0 corrosion, as evidenced by Fe 2+ release. The application of electrolysis could extend the working pH range of mFe 0 from 3.0 to 6.0 to 3.0-10.0 for PNP removal. Additionally, intermediates analysis and scavengers experiments unraveled the reduction capacity of mFe 0 was accelerated in the presence of electrolysis instead of oxidation. Moreover, the electrolysis effect could also delay passivation of mFe 0 under acidic condition, as evidenced by SEM-EDS, XRD, and XPS analysis after long-term operation. This is mainly due to increased electromigration meaning that iron corrosion products (iron hydroxides and oxides) are not primarily formed in the vicinity of the mFe 0 or at its surface. In the presence of electrolysis, the effect of electric field significantly promoted the efficiency of electromigration, thereby enhanced mFe 0 corrosion and eventually accelerated the PNP removal rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrolysis stimulates creatine transport and transporter cell surface expression in incubated mouse skeletal muscle: potential role of ROS.

PubMed

Derave, Wim; Straumann, Nadine; Olek, Robert A; Hespel, Peter

2006-12-01

Electrical field stimulation of isolated, incubated rodent skeletal muscles is a frequently used model to study the effects of contractions on muscle metabolism. In this study, this model was used to investigate the effects of electrically stimulated contractions on creatine transport. Soleus and extensor digitorum longus muscles of male NMRI mice (35-50 g) were incubated in an oxygenated Krebs buffer between platinum electrodes. Muscles were exposed to [(14)C]creatine for 30 min after either 12 min of repeated tetanic isometric contractions (contractions) or electrical stimulation of only the buffer before incubation of the muscle (electrolysis). Electrolysis was also investigated in the presence of the reactive oxygen species (ROS) scavenging enzymes superoxide dismutase (SOD) and catalase. Both contractions and (to a lesser degree) electrolysis stimulated creatine transport severalfold over basal. The amount of electrolysis, but not contractile activity, induced (determined) creatine transport stimulation. Incubation with SOD and catalase at 100 and 200 U/ml decreased electrolysis-induced creatine transport by approximately 50 and approximately 100%, respectively. The electrolysis effects on creatine uptake were completely inhibited by beta-guanidino propionic acid, a competitive inhibitor of (creatine for) the creatine transporter (CRT), and were accompanied by increased cell surface expression of CRT. Muscle glucose transport was not affected by electrolysis. The present results indicate that electrical field stimulation of incubated mouse muscles, independently of contractions per se, stimulates creatine transport by a mechanism that depends on electrolysis-induced formation of ROS in the incubation buffer. The increased creatine uptake is paralleled by an increased cell surface expression of the creatine transporter.

Evaluation of control over the microbiological contamination of carcasses in a lamb carcass dressing process operated with or without pasteurizing treatment.

PubMed

Milios, K; Mataragas, M; Pantouvakis, A; Drosinos, E H; Zoiopoulos, P E

2011-03-30

The aim of this study was to quantify the hygienic status of a lamb slaughterhouse by means of multivariate statistical analysis, to demonstrate how the microbiological data could be exploited to improve the lamb slaughter process by constructing control charts and to evaluate the potential effect of an intervention step such as steam application on the microbiological quality of lamb carcasses. Results showed that pelt removal and evisceration were hygienically uncontrolled. TVC and Enterobacteriaceae progressively increased from the stage 'after pelt removal of hind and forelegs/before final pulling' to the stage 'after evisceration/before pluck removal' thus indicating possible deposition of microorganisms during these operations. It seems that the processing stages of freshly produced carcasses were better distinguished by Enterobacteriaceae, with evisceration contributing mostly to the final Enterobacteriaceae counts. Application of steam during the lamb slaughter process reduced microbial counts without adverse effects on the organoleptic characteristics of the carcasses. Moreover, the construction of control charts showed that decontamination with steam contributed to the maintenance of an in control process compared to that before the application of steam, suggesting the potential use of steam as an intervention step during the lamb slaughter process. Copyright © 2011 Elsevier B.V. All rights reserved.

Steam thermolysis of tire shreds: modernization in afterburning of accompanying gas with waste steam

NASA Astrophysics Data System (ADS)

Kalitko, V. A.

2010-03-01

On the basis of experience in the commercial operation of tire-shred steam thermolysis in EnresTec Inc. (Taiwan) producing high-grade commercial carbon, liquid pyrolysis fuel, and accompanying fuel gas by this method, we have proposed a number of engineering solutions and calculated-analytical substantiations for modernization and intensification of the process by afterburning the accompanying gas with waste steam condensable in the scrubber of water gas cleaning of afterburning products. The condensate is completely freed of the organic pyrolysis impurities and the necessity of separating it from the liquid fuel, as is the case with the active process, is excluded.

Developing an energy efficient steam reforming process to produce hydrogen from sulfur-containing fuels

NASA Astrophysics Data System (ADS)

Simson, Amanda

Hydrogen powered fuel cells have the potential to produce electricity with higher efficiency and lower emissions than conventional combustion technology. In order to realize the benefits of a hydrogen fuel cell an efficient method to produce hydrogen is needed. Currently, over 90% of hydrogen is produced from the steam reforming of natural gas. However, for many applications including fuel cell vehicles, the use of a liquid fuel rather than natural gas is desirable. This work investigates the feasibility of producing hydrogen efficiently by steam reforming E85 (85% ethanol/15% gasoline), a commercially available sulfur-containing transportation fuel. A Rh-Pt/SiO2-ZrO2 catalyst has demonstrated good activity for the E85 steam reforming reaction. An industrial steam reforming process is often run less efficiently, with more water and at higher temperatures, in order to prevent catalyst deactivation. Therefore, it is desirable to develop a process that can operate without catalyst deactivation at more energy efficient conditions. In this study, the steam reforming of a sulfur-containing fuel (E85) was studied at near stoichiometric steam/carbon ratios and at 650C, conditions at which catalyst deactivation is normally measured. At these conditions the catalyst was found to be stable steam reforming a sulfur-free E85. However, the addition of low concentrations of sulfur significantly deactivated the catalyst. The presence of sulfur in the fuel caused catalyst deactivation by promoting ethylene which generates surface carbon species (coke) that mask catalytic sites. The amount of coke increased during time on stream and became increasingly graphitic. However, the deactivation due to both sulfur adsorption and coke formation was reversible with air treatment at 650°C. However, regenerations were found to reduce the catalyst life. Air regenerations produce exotherms on the catalyst surface that cause structural changes to the catalyst. During regenerations the accessibility of the precious metal particles is reduced which causes the catalyst to deactivate more rapidly during subsequent steam reforming cycles. Changes to the carrier morphology also occur at these conditions. Regenerating the catalyst before significant deactivation is measured can improve the stability of the catalyst. Thus a process with preemptive controlled air regenerations is proposed in order to run a steam reforming process with sulfur containing fuels.

METHANE STEAM REACTION OVER NICKEL CATALYSTS IN THE HYNOL PROCESS

EPA Science Inventory

The report discusses the reaction of methane-steam over nickel catalysts in the Hynol process, a process that uses biomass and natural gas as feedstocks to maximize methanol yields and minimize greenhouse gas emissions. EPA's APPCD has established a laboratory in which to conduct...

A transparent ultraviolet triggered amorphous selenium p-n junction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saito, Ichitaro; Soga, Kenichi; Overend, Mauro

2011-04-11

This paper will introduce a semitransparent amorphous selenium (a-Se) film exhibiting photovoltaic effects under ultraviolet light created through a simple and inexpensive method. We found that chlorine can be doped into a-Se through electrolysis of saturated salt water, and converts the weak p-type material into an n-type material. Furthermore, we found that a p-n diode fabricated through this process has shown an open circuit voltage of 0.35 V toward ultraviolet illumination. Our results suggest the possibility of doping control depending on the electric current during electrolysis and the possibility of developing a simple doping method for amorphous photoconductors.

Space Station propulsion electrolysis system - 'A technology challenge'

NASA Technical Reports Server (NTRS)

Le, Michael

1989-01-01

The Space Station propulsion system will utilize a water electrolysis system to produce the required eight-to-one ratio of gaseous hydrogen and oxygen propellants. This paper summarizes the state of the art in water electrolysis technologies and the supporting development programs at the NASA Lyndon B. Johnson Space Center. Preliminary proof of concept test data from a fully integrated propulsion testbed are discussed. The technical challenges facing the development of the high-pressure water electrolysis system are discussed.

Attenuated Allergenic Activity of Ovomucoid After Electrolysis

PubMed Central

Kido, Jun

2015-01-01

Ovomucoid (OMC) is the most prominent allergen causing hen's egg allergy, containing disulfide (S-S) bonds that may be responsible for its allergic action. As S-S bonds may be reduced during electrolysis, this study was undertaken to evaluate modulation of the allergic action of OMC after electrolysis. Electrolysis was carried out for 1% OMC containing 1% sodium chloride for 30 minutes with a voltage difference of 90 V, 0.23 A (30 mA/cm2). Protein assays, amino acid measurement, and mass spectrometry in untreated OMC and OMC on both the anode and cathode sides after electrolysis were performed. Moreover, 21 patients with IgE-mediated hen's egg allergy were evaluated by using the skin prick test (SPT) for untreated OMC and OMC after electrolysis. The allergic action of OMC was reduced after electrolysis on both the anode and cathode sides when evaluated by the SPT. The modifications of OMC on electrolysis caused the loss of 2 distinct peptide fragments (57E-63K and 123H-128R) as seen on matrix-associated laser desorption/ionization time-of-flight mass spectrometry. The total free SH groups in OMC were increased on the cathode side. Although the regions of S-S broken bonds were not determined in this study, the change in S-S bonds in OMC on both the anode and cathode sides may reduce the allergenic activity. PMID:26333707

Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czernik, S.; Wang, D.; Chornet, E.

1998-08-01

Hydrogen is the prototype of the environmentally cleanest fuel of interest for power generation using fuel cells and for transportation. The thermochemical conversion of biomass to hydrogen can be carried out through two distinct strategies: (a) gasification followed by water-gas shift conversion, and (b) catalytic steam reforming of specific fractions derived from fast pyrolysis and aqueous/steam processes of biomass. This paper presents the latter route that begins with fast pyrolysis of biomass to produce bio-oil. This oil (as a whole or its selected fractions) can be converted to hydrogen via catalytic steam reforming followed by a water-gas shift conversion step.more » Such a process has been demonstrated at the bench scale using model compounds, poplar oil aqueous fraction, and the whole pyrolysis oil with commercial Ni-based steam reforming catalysts. Hydrogen yields as high as 85% have been obtained. Catalyst initial activity can be recovered through regeneration cycles by steam or CO{sub 2} gasification of carbonaceous deposits.« less

Experimental research of heterogeneous nuclei in superheated steam

NASA Astrophysics Data System (ADS)

Bartoš, Ondřej; Kolovratník, Michal; Šmíd, Bohuslav; Hrubý, Jan

2016-03-01

A mobile steam expansion chamber has been developed to investigate experimentally homogeneous and heterogeneous nucleation processes in steam, both in the laboratory and at power plants using the steam withdrawn from the steam turbine. The purpose of the device is to provide new insight into the physics of nonequilibrium wet steam formation, which is one of the factors limiting the efficiency and reliability of steam turbines. The expanded steam or a mixture of steam with a non-condensable gas rapidly expands in the expansion chamber. Due to adiabatic cooling, the temperature drops below the dew point of the steam at a given pressure. When reaching a sufficiently high supersaturation, droplets are nucleated. By tuning the supersaturation in the so-called nucleation pulse, particles of various size ranges can be activated. This fact is used in the present study to measure the aerosol particles present in the air. Homogeneous nucleation was negligible in this case. The experiment demonstrates the functionality of the device, data acquisition system and data evaluation methods.

Anodes for alkaline electrolysis

DOEpatents

Soloveichik, Grigorii Lev [Latham, NY

2011-02-01

A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

Steam trap monitor

DOEpatents

Ryan, M.J.

1987-05-04

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellow in providing an indication of total energy (steam + condensate) of the system. Processing means coupled to and responsive to outputs from the hot and cold fingers subtracts the former from the latter to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning. 2 figs.

Detailed partial load investigation of a thermal energy storage concept for solar thermal power plants with direct steam generation

NASA Astrophysics Data System (ADS)

Seitz, M.; Hübner, S.; Johnson, M.

2016-05-01

Direct steam generation enables the implementation of a higher steam temperature for parabolic trough concentrated solar power plants. This leads to much better cycle efficiencies and lower electricity generating costs. For a flexible and more economic operation of such a power plant, it is necessary to develop thermal energy storage systems for the extension of the production time of the power plant. In the case of steam as the heat transfer fluid, it is important to use a storage material that uses latent heat for the storage process. This leads to a minimum of exergy losses during the storage process. In the case of a concentrating solar power plant, superheated steam is needed during the discharging process. This steam cannot be superheated by the latent heat storage system. Therefore, a sensible molten salt storage system is used for this task. In contrast to the state-of-the-art thermal energy storages within the concentrating solar power area of application, a storage system for a direct steam generation plant consists of a latent and a sensible storage part. Thus far, no partial load behaviors of sensible and latent heat storage systems have been analyzed in detail. In this work, an optimized fin structure was developed in order to minimize the costs of the latent heat storage. A complete system simulation of the power plant process, including the solar field, power block and sensible and latent heat energy storage calculates the interaction between the solar field, the power block and the thermal energy storage system.

Soft-sensing model of temperature for aluminum reduction cell on improved twin support vector regression

NASA Astrophysics Data System (ADS)

Li, Tao

2018-06-01

The complexity of aluminum electrolysis process leads the temperature for aluminum reduction cells hard to measure directly. However, temperature is the control center of aluminum production. To solve this problem, combining some aluminum plant's practice data, this paper presents a Soft-sensing model of temperature for aluminum electrolysis process on Improved Twin Support Vector Regression (ITSVR). ITSVR eliminates the slow learning speed of Support Vector Regression (SVR) and the over-fit risk of Twin Support Vector Regression (TSVR) by introducing a regularization term into the objective function of TSVR, which ensures the structural risk minimization principle and lower computational complexity. Finally, the model with some other parameters as auxiliary variable, predicts the temperature by ITSVR. The simulation result shows Soft-sensing model based on ITSVR has short time-consuming and better generalization.

Transient nanobubbles in short-time electrolysis

NASA Astrophysics Data System (ADS)

Svetovoy, Vitaly B.; Sanders, Remco G. P.; Elwenspoek, Miko C.

2013-05-01

Water electrolysis in a microsystem is observed and analyzed on a short-time scale of ∼10 μs. The very unusual properties of the process are stressed. An extremely high current density is observed because the process is not limited by the diffusion of electroactive species. The high current is accompanied by a high relative supersaturation, S > 1000, that results in homogeneous nucleation of bubbles. On the short-time scale only nanobubbles can be formed. These nanobubbles densely cover the electrodes and aggregate at a later time to microbubbles. The effect is significantly intensified with a small increase of temperature. Application of alternating polarity voltage pulses produces bubbles containing a mixture of hydrogen and oxygen. Spontaneous reaction between gases is observed for stoichiometric bubbles with sizes smaller than ∼150 nm. Such bubbles disintegrate violently affecting the surfaces of the electrodes.

Analysis of extracellular polymeric substances (EPS) and ciprofloxacin-degrading microbial community in the combined Fe-C micro-electrolysis-UBAF process for the elimination of high-level ciprofloxacin.

PubMed

Zhang, Longlong; Yue, Qinyan; Yang, Kunlun; Zhao, Pin; Gao, Baoyu

2018-02-01

Extracellular polymeric substances (EPS) and ciprofloxacin-degrading microbial community in the combined Fe-C micro-electrolysis and up-flow biological aerated filter (UBAF) process for the treatment of high-level ciprofloxacin (CIP) were analyzed. The research demonstrated a great potential of Fe-C micro-electrolysis-UBAF for the elimination of high-level CIP. Above 90% of CIP removal was achieved through the combined process at 100 mg L -1 of CIP loading. In UBAF, the pollutants were mainly removed at 0-70 cm heights. Three-dimensional fluorescence spectrum (3D-EEM) was used to characterize the chemical structural of loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) extracted from biofilm sample in UBAF. The results showed that the protein-like substances in LB-EPS and TB-EPS had no clear change in the study. Nevertheless, an obvious release of polysaccharides in EPSs was observed during long-term exposure to CIP, which was considered as a protective response of microbial to CIP toxic. The high-throughput sequencing results revealed that the biodiversity of bacteria community became increasingly rich with gradual ciprofloxacin biodegradation in UBAF. The ciprofloxacin-degrading microbial community was mainly dominated by Proteobacteria and Bacteroidetes. Microorganisms from genera Dechloromonas, Brevundimonas, Flavobacterium, Sphingopyxis and Bosea might take a major role in ciprofloxacin degradation. This study provides deep theoretical guidance for real CIP wastewater treatment. Copyright © 2017. Published by Elsevier Ltd.

Oxygen Production from Lunar Regolith using Ionic Liquids

NASA Technical Reports Server (NTRS)

Paley, Mark Steven; Karr, Laurel J.; Curreri, Peter

2009-01-01

The objective of this work and future follow-on work is to develop a safe, efficient, and recyclable method for oxygen and/or metals extraction from lunar regolith, in support of establishing a manned lunar outpost. The approach is to solubilize the oxides that comprise lunar regolith in media consisting of ionic liquids (ILs) and/or their mixtures at temperatures at or below 300 C. Once in solution, electrolysis can either be performed in-situ to generate oxygen at the anode and hydrogen and/or metals (silicon, iron, aluminum, titanium, etc.) at the cathode. Alternatively, the water that is generated during the solubilization process can be distilled out and condensed into a separate IL and then electrolysized to produce hydrogen and oxygen. In the case of lunar regolith, this method could theoretically produce 44g oxygen per 100g of regolith. The oxygen can be used for human life support and/or as an oxidizer for rocket fuels, and the metals can be used as raw materials for construction and/or device fabrication. Moreover, the hydrogen produced can be used to re-generate the acidic medium, which can then be used to process additional regolith, thereby making the materials recyclable and limiting upmass requirements. An important advantage of IL acid systems is that they are much "greener" and safer than conventional materials used for regolith processing such as sulfuric or hydrochloric acids. They have very low vapor pressures, which means that they contain virtually no toxic and/or flammable volatile content, they are relatively non-corrosive, and they can exhibit good stability in harsh environments (extreme temperatures, hard vacuum, etc.). Furthermore, regolith processing can be achieved at lower temperatures than other processes such as molten oxide electrolysis or hydrogen reduction, thereby reducing initial power requirements. Six ILs have been synthesized and tested for their capability to dissolve lunar simulant, and for electrochemical and thermal stability. The results showed that ILs can be very efficient electrolytes; in particular IL/phosphoric-acid mixtures appear extremely promising for solubilizing lunar simulant. Results from preliminary experiments for distillation of water produced from the oxygen within the metal oxides of the simulant and the hydrogen from the acid indicates that over 75% of the oxygen from the simulant can be harvested as water at a temperature of 150 C. A method for collection of oxygen from electrolysis of the water derived from solubilizing simulant was developed by using a liquid nitrogen trap to liquefy and collect the oxygen. Although precise quantification of the liquid oxygen trapped is difficult to obtain, the amount of hydrogen and oxygen collected from electrolysis of water in this system was greater than 98%. This set-up also included a portable mass spectrometer for the identification of gases released from electrolysis cells. Regeneration of ILs through re-protonation was also demonstrated. Four sequential re-generations of an IL following solubilization of simulant showed no significant differences in amounts of simulant dissolved. Follow-on work for this project should include more studies of IL/phosphoric acid systems. Also, much more work is necessary for defining methods for electrolysis and purification of metals from regolith solubilized in ILs, and for developing a system to use the produced hydrogen to regenerate the spent IL. Finally, design and development of flight breadboard and prototype hardware is required.

Degradation of 3,3'-iminobis-propanenitrile in aqueous solution by Fe(0)/GAC micro-electrolysis system.

PubMed

Lai, Bo; Zhou, Yuexi; Yang, Ping; Yang, Jinghui; Wang, Juling

2013-01-01

The degradation of 3,3'-iminobis-propanenitrile was investigated using the Fe(0)/GAC micro-electrolysis system. Effects of influent pH value, Fe(0)/GAC ratio and granular activated carbon (GAC) adsorption on the removal efficiency of the pollutant were studied in the Fe(0)/GAC micro-electrolysis system. The degradation of 3,3'-iminobis-propanenitrile was affected by influent pH, and a decrease of the influent pH values from 8.0 to 4.0 led to the increase of degradation efficiency. Granular activated carbon was added as cathode to form macroscopic galvanic cells between Fe(0) and GAC and enhance the current efficiency of the Fe(0)/GAC micro-electrolysis system. The GAC could only adsorb the pollutant and provide buffer capacity for the Fe(0)/GAC micro-electrolysis system, and the macroscopic galvanic cells of the Fe(0)/GAC micro-electrolysis system played a leading role in degradation of 3,3'-iminobis-propanenitrile. With the analysis of the degradation products with GC-MS, possible reaction pathway for the degradation of 3,3'-iminobis-propanenitrile by the Fe(0)/GAC micro-electrolysis system was suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

PubMed

Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal.

Desulfurizing Coal With an Alkali Treatment

NASA Technical Reports Server (NTRS)

Ravindram, M.; Kalvinskas, J. J.

1987-01-01

Experimental coal-desulfurization process uses alkalies and steam in fluidized-bed reactor. With highly volatile, high-sulfur bituminous coal, process removed 98 percent of pyritic sulfur and 47 percent of organic sulfur. Used in coal liquefaction and in production of clean solid fuels and synthetic liquid fuels. Nitrogen or steam flows through bed of coal in reactor. Alkalies react with sulfur, removing it from coal. Nitrogen flow fluidizes bed while heating or cooling; steam is fluidizing medium during reaction.

Can bread processing conditions alter glycaemic response?

PubMed

Lau, Evelyn; Soong, Yean Yean; Zhou, Weibiao; Henry, Jeyakumar

2015-04-15

Bread is a staple food that is traditionally made from wheat flour. This study aimed to compare the starch digestibility of western baked bread and oriental steamed bread. Four types of bread were prepared: western baked bread (WBB) and oriental steamed bread (OSB), modified baked bread (MBB) made with the OSB recipe and WBB processing, and modified steamed bread (MSB) made with the WBB recipe and OSB processing. MBB showed the highest starch digestibility in vitro, followed by WBB, OSB and MSB. A similar trend was observed for glycaemic response in vivo. MBB, WBB, OSB and MSB had a glycaemic index of 75±4, 71±5, 68±5 and 65±4, respectively. Processing differences had a more pronounced effect on starch digestibility in bread, and steamed bread was healthier in terms of glycaemic response. The manipulation of processing conditions could be an innovative route to alter the glycaemic response of carbohydrate-rich foods. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of acid impregnated steam explosion process on xylose recovery and enzymatic conversion of cellulose in corncob.

PubMed

Fan, Xiaoguang; Cheng, Gang; Zhang, Hongjia; Li, Menghua; Wang, Shizeng; Yuan, Qipeng

2014-12-19

Corncob residue is a cellulose-rich byproduct obtained from industrial xylose production via dilute acid hydrolysis processes. Enzymatic hydrolysis of cellulose in acid hydrolysis residue of corncob (AHRC) is often less efficient without further pretreatment. In this work, the process characteristics of acid impregnated steam explosion were studied in conjunction with a dilute acid process, and their effects on physiochemical changes and enzymatic saccharification of corncob residue were compared. With the acid impregnated steam explosion process, both higher xylose recovery and higher cellulose conversion were obtained. The maximum conversion of cellulose in acid impregnated steam explosion residue of corncob (ASERC) reached 85.3%, which was 1.6 times higher than that of AHRC. Biomass compositional analysis showed similar cellulose and lignin content in ASERC and AHRC. XRD analysis demonstrated comparable crystallinity of ASERC and AHRC. The improved enzymatic hydrolysis efficiency was attributed to higher porosity in ASERC, measured by mercury porosimetry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Potential applications for amylose inclusion complexes produced by steam jet cooking

USDA-ARS?s Scientific Manuscript database

Steam jet cooking is a commercially scalable method of thermomechanically processing starch for many applications. Previous studies at NCAUR have revealed the specific effects of heat and shear on various starch types cooked under different steam flow, pressure, and slurry flow conditions. Starch-...

40 CFR 429.80 - Applicability; description of the wood preserving-steam subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the wood... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Wood Preserving Steam Subcategory § 429.80 Applicability; description of the wood preserving—steam subcategory...

40 CFR 429.80 - Applicability; description of the wood preserving-steam subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the wood... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Wood Preserving Steam Subcategory § 429.80 Applicability; description of the wood preserving—steam subcategory...

Developing a Conceptual Model of STEAM Teaching Practices

ERIC Educational Resources Information Center

Quigley, Cassie F.; Herro, Dani; Jamil, Faiza M.

2017-01-01

STEAM, where the "A" represents arts and humanities, is considered a transdisciplinary learning process that has the potential to increase diverse participation in science, technology, engineering, and math (STEM) fields. However, a well-defined conceptual model that clearly articulates essential components of the STEAM approach is…

Preface–JES focus issue on electrolysis for increased renewable energy penetration

DOE PAGES

Pivovar, B.; Carmo, M.; Ayers, K.; ...

2016-10-22

The objective here of this special issue is to help identify the leading research being performed in the electrolysis area and provide context for the electrolysis advances that will be required for a larger role in tomorrow's energy system.

Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes.

PubMed

Winter, S; Smith, A; Lappin, D; McDonagh, G; Kirk, B

2017-12-01

Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organizations still advocate non-vacuum sterilization processes for these devices. To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations. Measurements at different positions within air turbines were undertaken with thermocouples and data loggers. Two examples of widely used UK benchtop steam sterilizers were tested: a non-vacuum benchtop sterilizer (Little Sister 3; Eschmann, Lancing, UK) and a vacuum benchtop sterilizer (Lisa; W&H, Bürmoos, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate. A total of 140 measurements inside dental handpiece lumens were recorded. The non-vacuum process failed (time range: 0-150 s) to reliably achieve sterilization temperatures within the time limit specified by the international standard (15 s equilibration time). The measurement point at the base of the handpiece failed in all test runs (N = 9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases. Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces, and the base of the handpiece is the site most likely to fail. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

The effects of steam injection in a sandstone reservoir (Etchegoin Formation), Buena Vista field, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant, C.W.; Reed, A.A.

1991-03-01

At Buena Vista field, California, 120 ft of post-steamflood core, spanning the middle Pliocene Wilhelm Member of the Etchegoin Formation, was taken to assess the influence of stratigraphy on light-oil steamflood (LOSF) processes and to determine what steam-rock reactions occurred and how these affected reservoir properties. High-quality steam (600F (300C)) had been injected ({approximately}1,700 psi) into mixed tidal flat and estuarine facies in an injector well located 55 ft from the cored well. Over a period of 20 months, steam rapidly channeled through a thin ({approximately}7 ft), relatively permeable (1-1,000 md), flaser-bedded sandstone unit. Conductive heating above this permeable unitmore » produced, in the vicinity of the cored well, a 35-ft steam-swept zone (oil saturation = 0), overlain by a 29-ft steam-affected zone in which oil saturation had been reduced to 13%, far below the presteam saturation of 30%. Steam-induced alteration ('artificial diagenesis') of the clay-rich reservoir rock was recognized using SEM, petrography, and X-ray diffraction. Salient dissolution effects were the complete to partial removal of siliceous microfossils, Fe-dolomite, volcanic rock fragments, and labile heavy minerals. The artificial diagenetic effects are first encountered in the basal 6 ft of the 29-ft steam-affected zone. Based on the distribution of the authigenic phases, the authors conclude that the reactions took place, or were at least initiated, in the steam condensate bank ahead of the advancing steam front. Although these changes presumably reduced permeability, the steamflood process was effective in reducing oil saturation to zero in the steam-contacted portion of the reservoir.« less

The use of advanced steam reforming technology for hydrogen production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbishaw, J.B.; Cromarty, B.J.

1996-12-01

The demand for supplementary hydrogen production in refineries is growing significantly world-wide as environmental legislation concerning cleaner gasoline and diesel fuels is introduced. The main manufacturing method is by steam reforming. The process has been developed both to reduce the capital cost and increase efficiency, reliability and ease of operation. ICI Katalco`s Leading Concept Hydrogen or LCH process continues this process of improvement by replacing the conventional fired steam reformer with a type of heat exchange reformer known as the Gas Heated Reformer or GHR. The GHR was first used in the Leading Concept Ammonia process, LCA at ICI`s manufacturingmore » site at Severnside, England and commissioned in 1988 and later in the Leading Concept Methanol (LCM) process for methanol at Melbourne, Australia and commissioned in 1994. The development of the LCH process follows on from both LCA and LCM processes. This paper describes the development and use of the GHR in steam reforming, and shows how the GHR can be used in LCH. A comparison between the LCH process and a conventional hydrogen plant is given, showing the benefits of the LCH process in certain circumstances.« less

Electrochemistry of the Hall-Heroult Process for Aluminum Smelting.

ERIC Educational Resources Information Center

Haupin, W. E.

1983-01-01

Nearly all aluminum is produced by the electrolysis of alumina dissolved in a molten cryolite-based electrolyte, the Hall-Heroult Process. Various aspects of the procedure are discussed, focusing on electrolyte chemistry, dissolution of alumina, electrode reactions, current efficiency, and cell voltage. Suggestions for graduate study related to…

26. Photocopy of diagram (from Bernhardt Skrotzki's Electric GenerationSteam Stations, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. Photocopy of diagram (from Bernhardt Skrotzki's Electric Generation--Steam Stations, New York, New York, 1956, figure I-1) THE GENERAL WAY IN WHICH ELECTRICITY IS CREATED THROUGH THE STEAM GENERATION PROCESS - Portland General Electric Company, Station "L", 1841 Southeast Water Street, Portland, Multnomah County, OR

Steaming Clean

ERIC Educational Resources Information Center

Hoverson, Rick

2006-01-01

Schools can provide a cleaner, more healthful school environment by simply combining heat and water. Steam vapor systems use only tap water with no chemicals added. Low-pressure (12 psi to 65 psi) steam vapor sanitizes and deodorizes. This process can then be used safely in many situations, but is especially suited for restrooms and food-service…

PHYSICAL AND OPTICAL PROPERTIES OF STEAM-EXPLODED LASER-PRINTED PAPER

EPA Science Inventory

Laser-printed paper was pulped by the steam-explosion process. A full-factorial experimental design was applied to determine the effects of key operating variables on the properties of steam-exploded pulp. The variables were addition level for pulping chemicals (NaOH and/or Na2SO...

75 FR 45080 - Revisions to the California State Implementation Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

... revisions concern oxides of nitrogen (NO X ) emissions from boilers, steam generators and process heaters... 1--Submitted Rule Local agency Rule No. Rule title Adopted Submitted SJVUAPCD 4308 Boilers, Steam... regulations that control NO X emissions. Rule 4308 limits NO X and CO emissions from boilers, steam generators...

Analysis of Economic Efficiency of Production of Low-Concentrated Sodium Hypochlorite by Direct Electrolysis of Natural Waters

NASA Astrophysics Data System (ADS)

Fesenko, L. N.; Pchelnikov, I. V.; Fedotov, R. V.

2017-11-01

The study presents the economic efficiency of direct electrolysis of natural waters in comparison with the waters artificially prepared by electrolysis of the 3% sodium salt solution. The study used sea water (Black sea water); mineral water (underground water of the Melikhovskaya station, “Ognennaya” hole); brackish water (underground water from the Grushevskaya station of the Aksai district); 3% solution of sodium salt. As a result, the dependences characterizing the direct electrolysis of natural waters with different mineralization, economic, and energy parties are shown. The rational area of the electrolysis for each of the investigated solution is determined. The cost of a kilogram of active chlorine obtained by the direct water electrolysis: Black sea from 17.2 to 18.3 RUB/kg; the Melikhovskaya station “Ognennaya” hole - 14.3 to 15.0 Rubles/kg; 3% solution of NaCl - 30 Rubles./kg; Grushevskogo St. - 63,0-73,0 Rubles/kg.

Simultaneous treatment of washing, disinfection and sterilization using ultrasonic levitation, silver electrolysis and ozone oxidation.

PubMed

Ueda, Toyotoshi; Hara, Masanori; Odagawa, Ikumi; Shigihara, Takanori

2009-03-01

A new type of ultrasonic washer-disinfector-sterilizer, able to clean, disinfect and sterilize most kinds of reusable medical devices, has been developed by using the ultrasonic levitation function with umbrella-shape oscillators and ozone bubbling together with sterilization carried out by silver electrolysis. We have examined the biomedical and physicochemical performance of this instrument. Prokariotic and gram-negative Escherichia coli and eukariotic Saccharomyces cerevisiae were killed by silver electrolysis in 18 min and 1 min, respectively. Prokariotic and gram-positive Geobacillus stearothermophilus and Bacillus atrophaeus, which are most resistant to autoclave and gas sterilization, respectively, were killed by silver electrolysis within 20 min. Prokariotic and gram-negative Pseudomonas aeruginosa was also killed by silver electrolysis in 10 min. The intensity distribution of the ultrasonic levitation waves was homogeneous throughout the tank. The concentration of ozone gas was 2.57 mg/ kg. The concentration of dissolved silver ions was around 0.17 mg/L. The disulfide bond in proteins was confirmed to be destroyed by silver electrolysis.

Applications of thermal energy storage to process heat storage and recovery in the paper and pulp industry

NASA Technical Reports Server (NTRS)

Carr, J. H.; Hurley, P. J.; Martin, P. J.

1978-01-01

Applications of Thermal Energy Storage (TES) in a paper and pulp mill power house were studied as one approach to the transfer of steam production from fossil fuel boilers to waste fuel of (hog fuel) boilers. Data from specific mills were analyzed, and various TES concepts evaluated for application in the process steam supply system. Constant pressure and variable pressure steam accumulators were found to be the most attractive storage concepts for this application.

Method for increasing steam decomposition in a coal gasification process

DOEpatents

Wilson, Marvin W.

1988-01-01

The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water-splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

Method to prevent/mitigate steam explosions in casting pits

DOEpatents

Taleyarkhan, Rusi P.

1996-01-01

Steam explosions can be prevented or mitigated during a metal casting process by the placement of a perforated flooring system in the casting pit. An upward flow of compressed gas through this perforated flooring system is introduced during the casting process to produce a buffer layer between any spilled molten metal and the cooling water in the reservoir. This buffer layer provides a hydrodynamic layer which acts to prevent or mitigate steam explosions resulting from hot, molten metal being spilled into or onto the cooling water.

Method for increasing steam decomposition in a coal gasification process

DOEpatents

Wilson, M.W.

1987-03-23

The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water- splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

Alkali-enhanced steam foam oil recovery process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lau, H.C.

1986-09-02

This patent describes a process in which steam and steam-foaming surfactant are injected into a subterranean reservoir for displacing a relatively acidic oil toward a production location. An improvement is described which consisits of: injecting into the reservoir, at least as soon as at least some portion of the steam is injected, (a) a kind and amount of water soluble, alkaline material effective for ion-exchanging multivalent ions from the reservoir rocks and precipitating compounds containing those ions and for causing the aqueous liquid phase of the injected fluid to form soaps of substantially all of the petroleum acids in themore » reservoir oil, and (b) at least one surfactant arranged for foaming the steam and providing a preformed cosurfactant material capable of increasing the salinity requirement of an aqueous surfactant system in which soaps derived from the reservoir oil comprise a primary surfactant.« less

Gasification of carbonaceous solids

DOEpatents

Coates, Ralph L.

1976-10-26

A process and apparatus for converting coal and other carbonaceous solids to an intermediate heating value fuel gas or to a synthesis gas. A stream of entrained pulverized coal is fed into the combustion stage of a three-stage gasifier along with a mixture of oxygen and steam at selected pressure and temperature. The products of the combustion stage pass into the second or quench stage where they are partially cooled and further reacted with water and/or steam. Ash is solidified into small particles and the formation of soot is suppressed by water/steam injections in the quench stage. The design of the quench stage prevents slag from solidifying on the walls. The products from the quench stage pass directly into a heat recovery stage where the products pass through the tube, or tubes, of a single-pass, shell and tube heat exchanger and steam is generated on the shell side and utilized for steam feed requirements of the process.

Graphical Procedure for Comparing Thermal Death of Bacillus stearothermophilus Spores in Saturated and Superheated Steam

PubMed Central

Shull, James J.; Ernst, Robert R.

1962-01-01

The thermal death curve of dried spores of Bacillus stearothermophilus in saturated steam was characterized by three phases: (i) a sharp initial rise in viable count; (ii) a low rate of death which gradually increased; and (iii) logarithmic death at maximal rate. The first phase was a reflection of inadequate heat activation of the spore population. The second and third phases represented the characteristic thermal death curve of the spores in saturated steam. A jacketed steam sterilizer, equipped with a system for initial evacuation of the chamber, was examined for superheat during normal operation. Measurements of spore inactivation and temperature revealed superheat in surface layers of fabrics being processed in steam at 121 C. The high temperature of the fabric surfaces was attributed to absorption of excess heat energy from superheated steam. The superheated steam was produced at the beginning of the normal sterilizing cycle by transfer of heat from the steam-heated jacket to saturated steam entering the vessel. PMID:13988774

Steam generation by combustion of processed waste fats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pudel, F.; Lengenfeld, P.

1993-12-31

The use of specially processed waste fats as a fuel oil substitute offers, at attractive costs, an environmentally friendly alternative to conventional disposal like refuse incineration or deposition. For that purpose the processed fat is mixed with EL fuel oil and burned in a standard steam generation plant equipped with special accessories. The measured emission values of the combustion processes are very low.

Trona-enhanced steam foam oil recovery process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lau, H.C.

1988-03-01

In a process in which steam and steam-foaming surfactant are injected into a subterranean reservoir for displacing a relatively acidic oil toward a production location, which process includes injecting into the reservoir, at least as soon as at least some portion of the steam is injected, (a) a kind and amount of water soluble, alkaline material effective for ion-exchanging multivalent ions from the reservoir rocks and precipitating compounds containing those ions and for causing the aqueous liquid phase of the injected fluid to form soaps of substantially all of the petroleum acids in the reservoir oil, and (b) at leastmore » one surfactant arranged for foaming the steam and providing a preformed cosurfactant material capable of increasing the salinity requirement of an aqueous surfactant system in which soaps derived from the reservoir oil comprise a primary surfactant, an improvement is described comprising: using as the water soluble alkaline material, a material consisting essentially of a substantially equal molar mixture of alkali metal carbonates and bicarbonates which is, or is substantially equivalent to, trona.« less

Veratric acid removal from water by electrochemical oxidation on BDD anode

NASA Astrophysics Data System (ADS)

Jum'h, Inshad; Abdelhay, Arwa; Telfah, Ahmad; Al-Akhras, M.-Ali; Al-Kazwini, Akeel; Rosiwal, Stefan

2018-02-01

The efficiency of boron doped diamond (BDD) in the electrochemical treatment of synthetically contaminated water with veratric acid (VA), one kind of polyphenolic type compounds, is investigated in this work. A BDD electrode was practically fabricated using hot filament chemical vapor deposition (HFCVD). Later on, the BDD electrode was implemented as an anode in a batch electrolytic reactor. The effect of operating factors such as the initial concentration of VA, NaCl addition, and supporting electrolyte type (H2SO4, H3PO4 and Na2SO4) was studied. The chemical oxygen demand (COD) measurements were conducted to study the VA electrolysis kinetics. The experimental data suggested that sodium sulfate was the best supporting electrolyte as the COD removal reached a percentage of 100% using 1 mmol/dm3 as VA concentration. The kinetics of the COD decay of the VA electrolysis were found to obey the pseudo-first order model. Remarkably, the electrolysis process is significantly speeded up once chloride is added to the reaction. The complete COD removal was achieved in 60 minutes of treatment.

Technology advancement of the static feed water electrolysis process

NASA Technical Reports Server (NTRS)

Jensen, F. C.; Schubert, F. H.

1977-01-01

Some results are presented of a research and development program to continue the development of a method to generate oxygen for crew metabolic consumption during extended manned space flights. The concept being pursued is that of static feed water electrolysis. Specific major results of the work included: (1) completion of a 30-day electrode test using a Life Systems, Inc.-developed high performance catalyst. During startup the cell voltages were as low as 1.38 V at current densities of 108 mA/sq cm (100 ASF) and temperatures of 355 K (180 F). At the end of 30 days of testing the cell voltages were still only 1.42 V at 108 mA/sq cm, (2) determination that the Static Feed Water Electrolysis Module does not release an aerosol of the cell electrolyte into the product gas streams after a break-in period of 24 hours following a new electrolyte charge, and (3) completion of a detailed design analysis of an electrochemical Oxygen Generation Subsystem at a three-man level (4.19 kg/day (9.24 lb/day) of oxygen).

Field-Assisted Splitting of Pure Water Based on Deep-Sub-Debye-Length Nanogap Electrochemical Cells.

PubMed

Wang, Yifei; Narayanan, S R; Wu, Wei

2017-08-22

Owing to the low conductivity of pure water, using an electrolyte is common for achieving efficient water electrolysis. In this paper, we have fundamentally broken through this common sense by using deep-sub-Debye-length nanogap electrochemical cells to achieve efficient electrolysis of pure water (without any added electrolyte) at room temperature. A field-assisted effect resulted from overlapped electrical double layers can greatly enhance water molecules ionization and mass transport, leading to electron-transfer limited reactions. We have named this process "virtual breakdown mechanism" (which is completely different from traditional mechanisms) that couples the two half-reactions together, greatly reducing the energy losses arising from ion transport. This fundamental discovery has been theoretically discussed in this paper and experimentally demonstrated in a group of electrochemical cells with nanogaps between two electrodes down to 37 nm. On the basis of our nanogap electrochemical cells, the electrolysis current density from pure water can be significantly larger than that from 1 mol/L sodium hydroxide solution, indicating the much better performance of pure water splitting as a potential for on-demand clean hydrogen production.

Electrosynthesis and characterization of zinc tungstate nanoparticles

NASA Astrophysics Data System (ADS)

Rahimi-Nasrabadi, Mehdi; Pourmortazavi, Seied Mahdi; Ganjali, Mohammad Reza; Hajimirsadeghi, Seiedeh Somayyeh; Zahedi, Mir Mahdi

2013-09-01

Zinc tungstate nanoparticles with different sizes are produced through an electrolysis process including a zinc plate anode in sodium tungstate solution. The shape and size of the product was found to be controlled by varying reaction parameters such as electrolysis voltage, stirring rate of electrolyte solution and temperature. The morphological (SEM) characterization analysis was performed on the product and UV-Vis spectrophotometry and FT-IR spectroscopy was utilized to characterize the electrodeposited nanoparticles. Study of the particle size of the product versus the electrolysis voltage showed that, increasing the voltage from 4 to 8 V, led to the particle size of zinc tungstate to decrease, but further increasing the voltage from 8 to 12 V, the particle size of the produced particles increased. The size and shape of the product was also found to be dependent on the stirring rate and temperature of the electrolyte solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR spectroscopy, and photoluminescence, were used to study the structure as well as composition of the nano-material prepared under optimum conditions.

Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

NASA Astrophysics Data System (ADS)

Fic, Adam; Składzień, Jan; Gabriel, Michał

2015-03-01

Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle), which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle). The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

UV-Vis as quantification tool for solubilized lignin following a single-shot steam process.

PubMed

Lee, Roland A; Bédard, Charles; Berberi, Véronique; Beauchet, Romain; Lavoie, Jean-Michel

2013-09-01

In this short communication, UV/Vis was used as an analytical tool for the quantification of lignin concentrations in aqueous mediums. A significant correlation was determined between absorbance and concentration of lignin in solution. For this study, lignin was produced from different types of biomasses (willow, aspen, softwood, canary grass and hemp) using steam processes. Quantification was performed at 212, 225, 237, 270, 280 and 287 nm. UV-Vis quantification of lignin was found suitable for different types of biomass making this a timesaving analytical system that could lead to uses as Process Analytical Tool (PAT) in biorefineries utilizing steam processes or comparable approaches. Copyright © 2013 Elsevier Ltd. All rights reserved.

Electrolysis Apparatus and a Method of Hydrodynamic Cavitation Protection.

DTIC Science & Technology

1974-09-17

AD-DO01 178 ELECTROLYSIS APPARATUS AND A METHOD OF HYDRODYNAMIC CAVITATION PROTECTION Earl Quandt, et al Department of the Navy Washington, D. C. 17...213" 261123 , Navy Case No. 57,238 ELECTROLYSIS APPARATUS AND A METHOD OF HYDRODYNAMIC CAVITATION PROTECTION 1 ABSTRACT Method of and apparatus for

[General and occupational morbidity in workers engaged into electrolysis nickel production in Transpolar Kolsky area].

PubMed

Tarnovskaia, E V; Siurin, S A; Chashchin, V P

2010-01-01

Findings are that occupational factors in nickel electrolysis workshops induce respiratory and peripheral nervous system diseases. Electrolysis workers demonstrate the highest prevalence and risk of occupational diseases. The authors make a conclusion on necessity to improve prophylactic methods for occupational disorders in these workers.

Simple Electrolyzer Model Development for High-Temperature Electrolysis System Analysis Using Solid Oxide Electrolysis Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

JaeHwa Koh; DuckJoo Yoon; Chang H. Oh

2010-07-01

An electrolyzer model for the analysis of a hydrogen-production system using a solid oxide electrolysis cell (SOEC) has been developed, and the effects for principal parameters have been estimated by sensitivity studies based on the developed model. The main parameters considered are current density, area specific resistance, temperature, pressure, and molar fraction and flow rates in the inlet and outlet. Finally, a simple model for a high-temperature hydrogen-production system using the solid oxide electrolysis cell integrated with very high temperature reactors is estimated.

Electrolysis of trichloromethylated organic compounds under aerobic conditions catalyzed by the B12 model complex for ester and amide formation.

PubMed

Shimakoshi, Hisashi; Luo, Zhongli; Inaba, Takuya; Hisaeda, Yoshio

2016-06-21

The electrolysis of benzotrichloride at -0.9 V vs. Ag/AgCl in the presence of the B12 model complex, heptamethyl cobyrinate perchlorate, in ethanol under aerobic conditions using an undivided cell equipped with a platinum mesh cathode and a zinc plate anode produced ethylbenzoate in 56% yield with 92% selectivity. The corresponding esters were obtained when the electrolysis was carried out in various alcohols such as methanol, n-propanol, and i-propanol. Benzoyl chloride was detected by GC-MS during the electrolysis as an intermediate for the ester formation. When the electrolysis was carried out under anaerobic conditions, partially dechlorinated products, 1,1,2,2-tetrachloro-1,2-diphenylethane and 1,2-dichlorostilibenes (E and Z forms), were obtained instead of an ester. ESR spin-trapping experiments using 5,5,-dimethylpyrroline N-oxide (DMPO) revealed that the corresponding oxygen-centered radical and carbon-centered radical were steadily generated during the electrolyses under aerobic and anaerobic conditions, respectively. Applications of the aerobic electrolysis to various organic halides, such as substituted benzotrichlorides, are described. Furthermore, the formation of amides with moderate yields by the aerobic electrolysis of benzotrichloride catalyzed by the B12 model complex in the presence of amines in acetonitrile is reported.

Aluminothermic Reduction-Molten Salt Electrolysis Using Inert Anode for Oxygen and Al-Base Alloy Extraction from Lunar Soil Simulant

NASA Astrophysics Data System (ADS)

Xie, Kaiyu; Shi, Zhongning; Xu, Junli; Hu, Xianwei; Gao, Bingliang; Wang, Zhaowen

2017-10-01

Aluminothermic reduction-electrolysis using an inert anode process is proposed to extract oxygen and metals from Minnesota Lunar Simulant-1 (MLS-1). Effective aluminothermic reduction between dissolved MLS-1 and dissolved metal aluminum was achieved in cryolite salt media. The product phases obtained by aluminothermic reduction at 980°C for 4 h were Al, Si, and Al5FeSi, while the chemical components were 79.71 mass% aluminum, 12.03 mass% silicon, 5.91 mass% iron, and 2.35 mass% titanium. The cryolite salt containing Al2O3 was subsequently electrolyzed with Fe0.58-Ni0.42 inert anode at 960°C for 4 h. Oxygen was evolved at the anode with an anodic current efficiency of 78.28%. The results demonstrate that this two-step process is remarkably feasible for the extraterrestrial extraction of oxygen and metals. This process will help expand the existing in situ resource utilization methods.

Lunar oxygen and metal for use in near-Earth space: Magma electrolysis

NASA Technical Reports Server (NTRS)

Colson, Russell O.; Haskin, Larry A.

1990-01-01

Because it is energetically easier to get material from the Moon to Earth orbit than from the Earth itself, the Moon is a potentially valuable source of materials for use in space. The unique conditions on the Moon, such as vacuum, absence of many reagents common on the Earth, and the presence of very nontraditional ores suggest that a unique and nontraditional process for extracting materials from the ores may prove the most practical. With this in mind, an investigation of unfluxed silicate electrolysis as a method for extracting oxygen, iron, and silicon from lunar regolith was initiated and is discussed. The advantages of the process include simplicity of concept, absence of need to supply reagents from Earth, and low power and mass requirements for the processing plant. Disadvantages include the need for uninterrupted high temperature and the highly corrosive nature of the high-temperature silicate melts which has made identifying suitable electrode and container materials difficult.

Pt-Pd bimetallic nanoparticles on MWCNTs: catalyst for hydrogen peroxide electrosynthesis

NASA Astrophysics Data System (ADS)

Félix-Navarro, R. M.; Beltrán-Gastélum, M.; Salazar-Gastélum, M. I.; Silva-Carrillo, C.; Reynoso-Soto, E. A.; Pérez-Sicairos, S.; Lin, S. W.; Paraguay-Delgado, F.; Alonso-Núñez, G.

2013-08-01

Bimetallic nanoparticles of Pt-Pd were deposited by the microemulsion method on a multiwall carbon nanotube (MWCNTs) to obtain a Pt-Pd/MWCNTs for electrocatalytic reduction of O2 to H2O2. The activity and selectivity of the catalyst was determined qualitatively by the rotating disk electrode method in acidic medium. The catalyst was spray-coated onto a reticulated vitreous carbon substrate and quantitatively was tested in bulk electrolysis for 20 min under potentiostatic conditions (0.5 V vs Ag/AgCl) in a 0.5 M H2SO4 electrolyte using dissolved O2. The bulk electrolysis experiments show that the Pt-Pd/MWCNTs catalyst is more efficient for H2O2 electrogeneration than a MWCNTs catalyst. Nitrobenzene degradation by electrogenerated H2O2 alone and Electro-Fenton process were also tested. Our results show that both processes decompose nitrobenzene, but the Electro-Fenton process does it more efficiently. The prepared nanoparticulated catalyst shows a great potential in environmental applications.

Thermodynamic equilibrium calculations of hydrogen production from the combined processes of dimethyl ether steam reforming and partial oxidation

NASA Astrophysics Data System (ADS)

Semelsberger, Troy A.; Borup, Rodney L.

Thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the combined processes of dimethyl ether (DME) partial oxidation and steam reforming were investigated as a function of oxygen-to-carbon ratio (0.00-2.80), steam-to-carbon ratio (0.00-4.00), temperature (100 °C-600 °C), pressure (1-5 atm) and product species. Thermodynamically, dimethyl ether processed with air and steam generates hydrogen-rich fuel-cell feeds; however, the hydrogen concentration is less than that for pure DME steam reforming. Results of the thermodynamic processing of dimethyl ether indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 °C, oxygen-to-carbon ratios greater than 0.00 and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure has negligible effects on the hydrogen content. Thermodynamically, dimethyl ether can produce concentrations of hydrogen and carbon monoxide of 52% and 2.2%, respectively, at a temperature of 300 °C, and oxygen-to-carbon ratio of 0.40, a pressure of 1 atm and a steam-to-carbon ratio of 1.50. The order of thermodynamically stable products (excluding H 2, CO, CO 2, DME, NH 3 and H 2O) in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol and methyl-ethyl ether; trace amounts of formaldehyde, formic acid and methanol are observed. Ammonia and hydrogen cyanide are also thermodynamically favored products. Ammonia is favored at low temperatures in the range of oxygen-to-carbon ratios of 0.40-2.50 regardless of the steam-to-carbon ratio employed. The maximum ammonia content (i.e., 40%) occurs at an oxygen-to-carbon ratio of 0.40, a steam-to-carbon ratio of 1.00 and a temperature of 100 °C. Hydrogen cyanide is favored at high temperatures and low oxygen-to-carbon ratios with a maximum of 3.18% occurring at an oxygen-to-carbon ratio of 0.40 and a steam-to-carbon ratio of 0.00 in the temperature range of 400 °C-500 °C. Increasing the system pressure shifts the equilibrium toward ammonia and hydrogen cyanide.

IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC. - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

This Innovative Technology Evaluation report summarizes the findings of an evaluation of the in situ Steam Enhanced Recovery Process (SERP) operated by Hughes Environmental Systems, Inc. at the Rainbow Disposal facility in Huntington Beach, California. he technology demonstration...

DEMONSTRATION BULLETIN: IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC.

EPA Science Inventory

The Steam Enhanced Recovery Process (SERP) is designed to remove volatile compounds such as halogenated solvents and petroleum hydrocarbons, and semi-volatile compounds from contaminated soils in situ. The vapor pressures of most contaminants will increase by the addition of ste...

Enhancement of waste activated sludge anaerobic digestion by a novel chemical free acid/alkaline pretreatment using electrolysis.

PubMed

Charles, W; Ng, B; Cord-Ruwisch, R; Cheng, L; Ho, G; Kayaalp, A

2013-01-01

Anaerobic digestion of waste activated sludge (WAS) is relatively poor due to hydrolysis limitations. Acid and alkaline pretreatments are effective in enhancing hydrolysis leading to higher methane yields. However, chemical costs often prohibit full-scale application. In this study, 12 V two-chamber electrolysis using an anion exchange membrane alters sludge pH without chemical dosing. pH dropped from 6.9 to 2.5 in the anode chamber and increased to 10.1 in the cathode chamber within 15 h. The volatile suspended solids solubilisation of WAS was 31.1% in the anode chamber and 34.0% in the cathode chamber. As a result, dissolved chemical oxygen demand increased from 164 to 1,787 mg/L and 1,256 mg/L in the anode and cathode chambers, respectively. Remixing of sludge from the two chambers brought the pH back to 6.5, hence no chemical neutralisation was required prior to anaerobic digestion. Methane yield during anaerobic digestion at 20 d retention time was 31% higher than that of untreated sludge. An energy balance assessment indicated that the non-optimised process could approximately recover the energy (electricity) expended in the electrolysis process. With suitable optimisation of treatment time and voltages, significant energy savings would be expected in addition to the benefit of decreased sludge volume.

Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

NASA Technical Reports Server (NTRS)

Burke, Kenneth A.; Jiao, Feng

2016-01-01

This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

Cathodic Potential Dependence of Electrochemical Reduction of SiO2 Granules in Molten CaCl2

NASA Astrophysics Data System (ADS)

Yang, Xiao; Yasuda, Kouji; Nohira, Toshiyuki; Hagiwara, Rika; Homma, Takayuki

2016-09-01

As part of an ongoing fundamental study to develop a new process for producing solar-grade silicon, this paper examines the effects of cathodic potential on reduction kinetics, current efficiency, morphology, and purity of Si product during electrolysis of SiO2 granules in molten CaCl2 at 1123 K (850 °C). SiO2 granules were electrolyzed potentiostatically at different cathodic potentials (0.6, 0.8, 1.0, and 1.2 V vs Ca2+/Ca). The reduction kinetics was evaluated based on the growth of the reduced Si layer and the current behavior during electrolysis. The results suggest that a more negative cathodic potential is favorable for faster reduction. Current efficiencies in 60 minutes are greater than 65 pct at all the potentials examined. Si wires with sub-micron diameters are formed, and their morphologies show little dependence on the cathodic potential. The impurities in the Si product can be controlled at low level. The rate-determining step for the electrochemical reduction of SiO2 granules in molten CaCl2 changes with time. At the initial stage of electrolysis, the electron transfer is the rate-determining step. At the later stage, the diffusion of O2- ions is the rate-determining step. The major cause of the decrease in reduction rate with increasing electrolysis time is the potential drop from the current collector to the reaction front due to the increased contact resistance among the reduced Si particles.

Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

PubMed Central

Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

2017-01-01

A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m3. During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS. PMID:28345583

Water electrolysis with a conducting carbon cloth: subthreshold hydrogen generation and superthreshold carbon quantum dot formation.

PubMed

Biswal, Mandakini; Deshpande, Aparna; Kelkar, Sarika; Ogale, Satishchandra

2014-03-01

A conducting carbon cloth, which has an interesting turbostratic microstructure and functional groups that are distinctly different from other ordered forms of carbon, such as graphite, graphene, and carbon nanotubes, was synthesized by a simple one-step pyrolysis of cellulose fabric. This turbostratic disorder and surface chemical functionalities had interesting consequences for water splitting and hydrogen generation when such a cloth was used as an electrode in the alkaline electrolysis process. Importantly, this work also gives a new twist to carbon-assisted electrolysis. During electrolysis, the active sites in the carbon cloth allow slow oxidation of its surface to transform the surface groups from COH to COOH and so forth at a voltage as low as 0.2 V in a two-electrode system, along with platinum as the cathode, instead of 1.23 V (plus overpotential), which is required for platinum, steel, or even graphite anodes. The quantity of subthreshold hydrogen evolved was 24 mL cm(-2)  h(-1) at 1 V. Interestingly, at a superthreshold potential (>1.23 V+overpotential), another remarkable phenomenon was found. At such voltages, along with the high rate and quantity of hydrogen evolution, rapid exfoliation of the tiny nanoscale (5-7 nm) units of carbon quantum dots (CQDs) are found in copious amounts due to an enhanced oxidation rate. These CQDs show bright-blue fluorescence under UV light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

NASA Astrophysics Data System (ADS)

Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

2017-03-01

A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m3. During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS.

Microbial safety and overall quality of cantaloupe fresh-cut pieces prepared from whole fruit after wet steam treatment

USDA-ARS?s Scientific Manuscript database

Fresh-cut cantaloupes have been associated with outbreaks of Salmonellosis. Minimally processed fresh-cut fruits have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. The objectives of this study were to use a wet steam process to 1) reduce ind...

The effect of saturated steam vapor temperature on heat consumption in the process of color modification of acacia wood

NASA Astrophysics Data System (ADS)

Dzurenda, Ladislav

2017-09-01

This paper presents the heat consumption on the process of colour modification of acacia timber with measures 30 x 55 x 500 mm in pressure autoclaves AZ 240 using saturated water steam with temperatures from t = 110 to 140 °C following the regimes of colour homogenisation of I., II. and III. degree. The dependance of the heat consumption normative QTFS on the temparature of saturated water steam in the process of colour homogenisation of acacia timber following these regimes describes the equation: QTFS = 1.1122.t -13.903 kWh.m-3.

40 CFR 98.62 - GHGs to report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... electrolysis cells. (b) CO2 emissions from anode consumption during electrolysis in all prebake and Søderberg electrolysis cells. (c) CO2 emissions from on-site anode baking. (d) You must report under subpart C of this part (General Stationary Fuel Combustion Sources) the emissions of CO2, N2O, and CH4 emissions from...

40 CFR 98.62 - GHGs to report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... electrolysis cells. (b) CO2 emissions from anode consumption during electrolysis in all prebake and Søderberg electrolysis cells. (c) CO2 emissions from on-site anode baking. (d) You must report under subpart C of this part (General Stationary Fuel Combustion Sources) the emissions of CO2, N2O, and CH4 emissions from...

40 CFR 98.62 - GHGs to report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... electrolysis cells. (b) CO2 emissions from anode consumption during electrolysis in all prebake and Søderberg electrolysis cells. (c) CO2 emissions from on-site anode baking. (d) You must report under subpart C of this part (General Stationary Fuel Combustion Sources) the emissions of CO2, N2O, and CH4 emissions from...

A Vivens Ex Vivo Study on the Synergistic Effect of Electrolysis and Freezing on the Cell Nucleus.

PubMed

Lugnani, Franco; Zanconati, Fabrizio; Marcuzzo, Thomas; Bottin, Cristina; Mikus, Paul; Guenther, Enric; Klein, Nina; Rubinsky, Liel; Stehling, Michael K; Rubinsky, Boris

2015-01-01

Freezing-cryosurgery, and electrolysis-electrochemical therapy (EChT), are two important minimally invasive surgery tissue ablation technologies. Despite major advantages they also have some disadvantages. Cryosurgery cannot induce cell death at high subzero freezing temperatures and requires multiple freeze thaw cycles, while EChT requires high concentrations of electrolytic products-which makes it a lengthy procedure. Based on the observation that freezing increases the concentration of solutes (including products of electrolysis) in the frozen region and permeabilizes the cell membrane to these products, this study examines the hypothesis that there could be a synergistic effect between freezing and electrolysis in their use together for tissue ablation. Using an animal model we refer to as vivens ex vivo, which may be of value in reducing the use of animals for experiments, combined with a Hematoxylin stain of the nucleus, we show that there are clinically relevant protocols in which the cell nucleus appears intact when electrolysis and freezing are used separately but is affected by certain combinations of electrolysis and freezing.

ELECTROLYSIS AND ION EXCHANGE FOR THE IN PROCESS RECYCLING OF COPPER FROM SEMI-CONDUCTOR PROCESSING SOLUTIONS

EPA Science Inventory

The objectives of the study are to develop an understanding of the electrodeposition of copper onto extended-area electrodes, and of the adsorption/desorption of copper onto ion exchange resins with a high affinity for copper. The principles elucidated in this work will pave the ...

40 CFR 63.441 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... flash steam from the digester or live steam. Closed-vent system means a system that is not open to the... this subpart, including emissions from individual process vents, stacks, open pieces of process... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

40 CFR 63.441 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... flash steam from the digester or live steam. Closed-vent system means a system that is not open to the... this subpart, including emissions from individual process vents, stacks, open pieces of process... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

40 CFR 63.441 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... flash steam from the digester or live steam. Closed-vent system means a system that is not open to the... this subpart, including emissions from individual process vents, stacks, open pieces of process... stock chests, and their associated vacuum pumps, filtrate tanks, foam breakers or tanks, and any other...

Oxygen production processes on the Moon: An overview

NASA Technical Reports Server (NTRS)

Taylor, Lawrence A.; Carrier, W. David, III

1991-01-01

The production of oxygen on the Moon utilizing indigenous material is paramount to a successful lunar colonization. Several processes were put forth to accomplish this. The lunar liquid oxygen (LLOX) generation schemes which have received the most study to date are those involving: (1) the reduction of ilmenite (FeTiO3) by H2, C, CO, CH4, CO-Cl2 plasma; (2) magma electrolysis, both unadulterated and fluoride-fluxed, and (3) several others, including carbo-chlorination, HF acid leaching, fluorine extraction, magma oxidation, and vapor pyrolysis. The H2 reduction of ilmenite and magma electrolysis processes have received the most study to date. At this stage of development, they both appear feasible schemes with various pros and cons. However, all processes should be addressed at least at the onset of the considerations. It is ultimatley the energy requirements of the entire process, including the acquisition of feedstock, which will determine the mode of oxygen productions. There is an obvious need for considerably more experimentation and study. Some of these requisite studies are in progress, and several of the most studied and feasible processes for winning oxygen from lunar materials are reviewed.

Off-design analysis of a gas turbine powerplant augmented by steam injection using various fuels

NASA Technical Reports Server (NTRS)

Stochl, R. J.

1980-01-01

Results are compared using coal derived low and intermediate heating valve fuel gases and a conventional distillate. The results indicate that steam injection provides substantial increases in both power and efficiency within the available compressor surge margin. The results also indicate that these performance gains are relatively insensitive as to the type of fuel. Also, in a cogeneration application, steam injection could provide some degree of flexibility by varying the split between power and process steam.

Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

NASA Technical Reports Server (NTRS)

Mwara, Kamwana N.

2015-01-01

Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

An electro-amalgamation approach to isolate no-carrier-added 177Lu from neutron irradiated Yb for biomedical applications.

PubMed

Chakravarty, Rubel; Das, Tapas; Dash, Ashutosh; Venkatesh, Meera

2010-10-01

A novel two-step separation process for the production of no-carrier-added (NCA) (177)Lu from neutron irradiated Yb target through an electrochemical pathway employing mercury-pool cathode has been developed. A two-cycle electrolysis procedure was adopted for separation of (177)Lu from (177)Lu/Yb mixture in lithium citrate medium. The influence of different experimental parameters on the separation process was investigated and optimized for the quantitative deposition of Yb in presence of (177)Lu. The first electrolysis was performed for 50 min in the (177)Lu/Yb feed solution at pH 6 applying a potential of 8 V using platinum electrode as anode and mercury as the cathode. The second electrolysis was performed under the same conditions using fresh electrodes. The radionuclidic and chemical purity of (177)Lu was determined by using gamma ray spectrometry and atomic absorption spectrometry. The suitability of (177)Lu for biomedical applications was ascertained by labeling 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid D-Phe(1)-Tyr(3)-octreotate(DOTA-TATE) with (177)Lu. This process could provide NCA (177)Lu with >99.99% radionuclidic purity and an overall separation yield of ∼99% was achieved within 3-4 h. The Hg content in the product was determined to be <1 ppm. Radiolabeling yield of >98% was obtained with DOTA-TATE under the optimized reaction conditions. An efficient strategy for the separation of NCA (177)Lu, suitable for biomedical applications, has been developed. Copyright © 2010 Elsevier Inc. All rights reserved.

Heat exchanger for fuel cell power plant reformer

DOEpatents

Misage, Robert; Scheffler, Glenn W.; Setzer, Herbert J.; Margiott, Paul R.; Parenti, Jr., Edmund K.

1988-01-01

A heat exchanger uses the heat from processed fuel gas from a reformer for a fuel cell to superheat steam, to preheat raw fuel prior to entering the reformer and to heat a water-steam coolant mixture from the fuel cells. The processed fuel gas temperature is thus lowered to a level useful in the fuel cell reaction. The four temperature adjustments are accomplished in a single heat exchanger with only three heat transfer cores. The heat exchanger is preheated by circulating coolant and purge steam from the power section during startup of the latter.

Effect of the presence of oil on foam performance; A field simulation study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Law, D.H.S.; Yang, Z.M.; Stone, T.W.

1992-05-01

This paper describes a field-scale sensitivity study of the effect of the presence of oil on foam performance in a steam-foam-drive process. The 2D field-scale simulation was based on a field pilot in the Karamay formation in Zin-Jiang, China. Numerical results showed that the detrimental effect of oil on the foam performance in field operations is significant. The success of a steam-foam process depended mainly on the ability of the foam to divert steam from the depleted zone.

Method to prevent/mitigate steam explosions in casting pits

DOEpatents

Taleyarkhan, R.P.

1996-12-24

Steam explosions can be prevented or mitigated during a metal casting process by the placement of a perforated flooring system in the casting pit. An upward flow of compressed gas through this perforated flooring system is introduced during the casting process to produce a buffer layer between any spilled molten metal and the cooling water in the reservoir. This buffer layer provides a hydrodynamic layer which acts to prevent or mitigate steam explosions resulting from hot, molten metal being spilled into or onto the cooling water. 3 figs.

The Development and Application of a STEAM Program Based on Traditional Korean Culture

ERIC Educational Resources Information Center

Kim, Hyoungbum; Chae, Dong-Hyun

2016-01-01

The purpose of this research was to develop a STEAM program in the context of teaching and learning a traditional Korean instrument and implement it in a high school class to determine the program's effectiveness. The STEAM program was developed through a continuous consultation process between a development team and external experts, including an…

Effects of press sizes on internal steam pressure during particleboard hot-pressing process

Treesearch

Zhiyong Cai; Michael Birkeland; James M. Wescott; Jane O' Dell; Jerrold E. Winandy

2009-01-01

Internal steam pressure produced during the hot-pressing cycle in particleboard production is critical to the newly developed bond strength that will determine the overall performance of particleboard. The difference between the accumulation of internal steam pressure for small panels made in the laboratory and that of large commercial-sized panels makes it difficult...

An integrated microbial electrolysis-anaerobic digestion process combined with pretreatment of wastewater solids to improve hydrogen production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beegle, Jeff R.; Borole, Abhijeet P.

A combined anaerobic digestion (AD) and microbial electrolysis cell (MEC) system, named here as ADMEC, was investigated in this paper to evaluate the energy recovery from pretreated wastewater solids. Alkaline and thermal hydrolysis pretreatment methods increased the solubility of organic compounds present in the raw solids by 25% and 20%, respectively. The soluble phase from pretreatment was separated and used for microbial electrolysis, whereas the insoluble fraction was fed into semi-continuous digesters. The digester effluent was later utilized as a second MEC substrate. The pretreatment had variable effects on AD and MEC performance. The methane content in AD biogas wasmore » higher in pretreated groups, 78.29 ± 2.89% and 73.2 ± 1.79%, for alkaline and thermal, than the control, 50.26 ± 0.53%, but the overall biogas production rates were lower than the control, 20 and 30 mL CH 4 gCOD -1 d -1 for alkaline and thermal compared to 80 mL CH 4 gCOD -1 d -1. The effluent streams from thermally pretreated digesters were the best substrate for microbial electrolysis, in terms of hydrogen production and efficiency. The MECs produced 1.7 ± 0.2 L-H 2 per L per day, 0.3 ± 0.1 L-H 2 per L per day, and 0.29 ± 0.1 L-H 2 per L per day, for thermal, alkaline, and control reactors. The productivity was lower compared to acetate and propionate controls, which yielded 5.79 ± 0.03 L-H 2 per L per day and 3.49 ± 0.10 L-H 2 per L per day, respectively. The pretreatment solubilized fractions were not ideal substrates for microbial electrolysis. Finally, a chemical oxygen demand (COD) mass balance showed that pretreatment shifts the electron flux away from methane and biomass sinks towards hydrogen production.« less

An integrated microbial electrolysis-anaerobic digestion process combined with pretreatment of wastewater solids to improve hydrogen production

DOE PAGES

Beegle, Jeff R.; Borole, Abhijeet P.

2017-08-17

A combined anaerobic digestion (AD) and microbial electrolysis cell (MEC) system, named here as ADMEC, was investigated in this paper to evaluate the energy recovery from pretreated wastewater solids. Alkaline and thermal hydrolysis pretreatment methods increased the solubility of organic compounds present in the raw solids by 25% and 20%, respectively. The soluble phase from pretreatment was separated and used for microbial electrolysis, whereas the insoluble fraction was fed into semi-continuous digesters. The digester effluent was later utilized as a second MEC substrate. The pretreatment had variable effects on AD and MEC performance. The methane content in AD biogas wasmore » higher in pretreated groups, 78.29 ± 2.89% and 73.2 ± 1.79%, for alkaline and thermal, than the control, 50.26 ± 0.53%, but the overall biogas production rates were lower than the control, 20 and 30 mL CH 4 gCOD -1 d -1 for alkaline and thermal compared to 80 mL CH 4 gCOD -1 d -1. The effluent streams from thermally pretreated digesters were the best substrate for microbial electrolysis, in terms of hydrogen production and efficiency. The MECs produced 1.7 ± 0.2 L-H 2 per L per day, 0.3 ± 0.1 L-H 2 per L per day, and 0.29 ± 0.1 L-H 2 per L per day, for thermal, alkaline, and control reactors. The productivity was lower compared to acetate and propionate controls, which yielded 5.79 ± 0.03 L-H 2 per L per day and 3.49 ± 0.10 L-H 2 per L per day, respectively. The pretreatment solubilized fractions were not ideal substrates for microbial electrolysis. Finally, a chemical oxygen demand (COD) mass balance showed that pretreatment shifts the electron flux away from methane and biomass sinks towards hydrogen production.« less

Steam trap monitor

DOEpatents

Ryan, Michael J.

1988-01-01

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellows in providing an indication of total energy (steam+condensate) of the system. Processing means coupled to and responsive to outputs from the thermocouple well hot and cold fingers subtracts the condensate energy as measured by the hot finger and thermocouple well from the total energy as measured by the cold finger to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning.

Cyclic steaming in heavy oil diatomite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, M.; Beatty, F.D.

1995-12-31

Chevron currently uses cyclic steaming as a recovery method to produce economically its heavy oil diatomite resource in the Cymric field, San Joaquin Valley, California. A highly instrumented, cyclically steaming well from this field was simulated in this study to delineate important production mechanisms, to optimize operations, and to improve reservoir management. The model was constrained, as much as possible, by the available measured data. Results show that fluid flow from the well to the reservoir is primarily through the hydraulic fracture induced by the injected steam. Parameters with unique importance to modeling cyclic steaming in diatomites are: (1) inducedmore » fracture dimension (length and height), (2) matrix permeability, (3) oil/water capillary pressure, (4) grid size perpendicular to fracture face, and (5) producing bottomhole pressures. Additionally, parameters important for conventional steam injection processes, such as relative permeabilities and injected steam volume, quality, and rate, are important for diatomites also. Oil production rates and steam/oil ratios calculated by this model compare reasonably with field data.« less

Electrochemical disinfection of coliform and Escherichia coli for drinking water treatment by electrolysis method using carbon as an electrode

NASA Astrophysics Data System (ADS)

Riyanto; Agustiningsih, W. A.

2018-04-01

Disinfection of coliform and E. Coli in water has been performed by electrolysis using carbon electrodes. Carbon electrodes were used as an anode and cathode with a purity of 98.31% based on SEM-EDS analysis. This study was conducted using electrolysis powered by electric field using carbon electrode as the anode and cathode. Electrolysis method was carried out using variations of time (30, 60, 90, 120 minutes at a voltage of 5 V) and voltage (5, 10, 15, 20 V for 30 minutes) to determine the effect of the disinfection of the bacteria. The results showed the number of coliform and E. coli in water before and after electrolysis was 190 and 22 MPN/100 mL, respectively. The standards quality of drinking water No. 492/Menkes/Per/IV/2010 requires the zero content of coliform and E. Coli. Electrolysis with the variation of time and potential can reduce the number of coliforms and E. Coli but was not in accordance with the standards. The effect of hydrogen peroxide (H2O2) to the electrochemical disinfection was determined using UV-Vis spectrophotometer. The levels of H2O2 formed increased as soon after the duration of electrolysis voltage but was not a significant influence to the mortality of coliform and E.coli.

Downhole measurements and fluid chemistry of a castle rock steam well, the Geysers, Lake County, California

USGS Publications Warehouse

Truesdell, A.H.; Nathenson, M.; Frye, G.A.

1981-01-01

Wellbore and reservoir processes in a steam well in the Castle Rock field of The Geysers have been studied by means of down-hole pressure and temperature measurements and analyses of ejected water and steam produced under bleed and full flow. Down-hole measurements show that below a vapor zone there is liquid water in the well in pressure equilibrium with reservoir steam at a depth of 2290 m. The progressive decreases, from 1973 to 1977, of pressure and temperature in the vapor zone indicate that wellbore heat loss is high enough to condense a large fraction of the steam inflow. The chemical composition of water ejected from the well is consistent with an origin from wellbore condensation of steam. Calculations using the differences in gas and isotopic compositions between bleed and full-flow steam show that about half of the full-flow steam originated as liquid water in the reservoir and that about 30% of the steam entering the well under bleed was condensed in the wellbore and drained downward. Heat loss calculations are also consistent with this amount of condensation. ?? 1981.

Evaluation of rock/fracture interactions during steam injection through vertical hydrofractures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovscek, A.R.; Johnston, R.M.; Patzek, T.W.

1995-12-31

This paper illustrates the design and results of Shell`s Phase 2 steam drive pilot in the South Belridge Diatomite, Kern County, California. Steam drive on 5/8 acre spacing appears to be an economically viable alternative to waterflooding in the Diatomite; hence, it is being explored as a secondary recovery process. The purpose of the Phase 2 pilot was to demonstrate that steam could be injected across the full Diatomite interval and to quantify reservoir heating and volumetric sweep by steam. In this pilot, two separate, noncommunicating hydrofractures that span the entire Diatomite column (1,110--1,910 ft) are used for injection. Tomore » interpret quantitatively steam drive results the authors propose a computationally simple, high resolution model that captures formation heating due to both steam/hot condensate convection and heat conduction, evolution of formation permeability, and changes in the size and shape of the injection hydrofractures. From this model they obtain formation pressure, temperature, the cumulative steam injection, the dynamics of hydrofractures while they undergo steam injection, and, thus, a history match for the pilot.« less

Electrolysis of Water in the Secondary School Science Laboratory with Inexpensive Microfluidics

ERIC Educational Resources Information Center

Davis, T. A.; Athey, S. L.; Vandevender, M. L.; Crihfield, C. L.; Kolanko, C. C. E.; Shao, S.; Ellington, M. C. G.; Dicks, J. K.; Carver, J. S.; Holland, L. A.

2015-01-01

This activity allows students to visualize the electrolysis of water in a microfluidic device in under 1 min. Instructional materials are provided to demonstrate how the activity meets West Virginia content standards and objectives. Electrolysis of water is a standard chemistry experiment, but the typical laboratory apparatus (e.g., Hoffman cell)…

Development of a solid polymer electrolyte electrolysis cell module and ancillary components for a breadboard water electrolysis system

NASA Technical Reports Server (NTRS)

Porter, F. J., Jr.

1972-01-01

Solid polymer electrolyte technology in a water electrolysis system along with ancillary components to generate oxygen and hydrogen for a manned space station application are considered. Standard commercial components are utilized wherever possible. Presented are the results of investigations, surveys, tests, conclusions and recommendations for future development efforts.

A fast response miniature probe for wet steam flow field measurements

NASA Astrophysics Data System (ADS)

Bosdas, Ilias; Mansour, Michel; Kalfas, Anestis I.; Abhari, Reza S.

2016-12-01

Modern steam turbines require operational flexibility due to renewable energies’ increasing share of the electrical grid. Additionally, the continuous increase in energy demand necessitates efficient design of the steam turbines as well as power output augmentation. The long turbine rotor blades at the machines’ last stages are prone to mechanical vibrations and as a consequence time-resolved experimental data under wet steam conditions are essential for the development of large-scale low-pressure steam turbines. This paper presents a novel fast response miniature heated probe for unsteady wet steam flow field measurements. The probe has a tip diameter of 2.5 mm, and a miniature heater cartridge ensures uncontaminated pressure taps from condensed water. The probe is capable of providing the unsteady flow angles, total and static pressure as well as the flow Mach number. The operating principle and calibration procedure are described in the current work and a detailed uncertainty analysis demonstrates the capability of the new probe to perform accurate flow field measurements under wet steam conditions. In order to exclude any data possibly corrupted by droplets’ impact or evaporation from the heating process, a filtering algorithm was developed and implemented in the post-processing phase of the measured data. In the last part of this paper the probe is used in an experimental steam turbine test facility and measurements are conducted at the inlet and exit of the last stage with an average wetness mass fraction of 8.0%.

Conceptual design assessment for the co-firing of bio-refinery supplied lignin project. Quarterly report, July 1--September 30, 2000

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berglund, T.; Ranney, J.T.; Babb, C.L.

2000-10-01

The initial design criteria of the MSW to ethanol facility have been completed along with preliminary site identification and layouts for the processing facility. These items are the first step in evaluating the feasibility of this co-located facility. Pilot facility design and modification are underway for the production and dewatering of the lignin fuel. Major process equipment identification has been completed and several key unit operations will be accomplished on rental equipment. Equipment not available for rental or at TVA has been ordered and facility modification and shakedown will begin in October. The study of the interface and resulting impactsmore » on the TVA Colbert facility are underway. The TVA Colbert fossil plant is fully capable of providing a reliable steam supply for the proposed Masada waste processing facility. The preferred supply location in the Colbert steam cycle has been identified as have possible steam pipeline routes to the Colbert boundary. Additional analysis is underway to fully predict the impact of the steam supply on Colbert plant performance and to select a final steam pipeline route.« less

Effects of water states on steam explosion of lignocellulosic biomass.

PubMed

Sui, Wenjie; Chen, Hongzhang

2016-01-01

The work aimed to identify the complexity and roles of water states in steam explosion process of corn stalk to enhance the treatment efficiency. Results showed that two main water states with different mobility existed in corn stalk and influenced steam explosion treatment. By correlating dynamic water states data to feedstock mechanical properties and treatment process characteristics, the bound water being the excellent plasticizer that reduced the mechanical strength of fibers by over 30%, was conducive to treatment; while, the free water presenting buffering effects in treatment by hindering heat transfer which was reflected by the increase of temperature rising time by 1.29 folds and steam consumption by 2.18 folds, was not conducive. The distinguished point of these two waters was fiber saturated point. By considering treatment efficacy and energy consumption, the significance of fiber saturated point was highlighted as the optimal water states for steam explosion of corn stalk. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimation of water level and steam temperature using ensemble Kalman filter square root (EnKF-SR)

NASA Astrophysics Data System (ADS)

Herlambang, T.; Mufarrikoh, Z.; Karya, D. F.; Rahmalia, D.

2018-04-01

The equipment unit which has the most vital role in the steam-powered electric power plant is boiler. Steam drum boiler is a tank functioning to separate fluida into has phase and liquid phase. The existence in boiler system has a vital role. The controlled variables in the steam drum boiler are water level and the steam temperature. If the water level is higher than the determined level, then the gas phase resulted will contain steam endangering the following process and making the resulted steam going to turbine get less, and the by causing damages to pipes in the boiler. On the contrary, if less than the height of determined water level, the resulted height will result in dry steam likely to endanger steam drum. Thus an error was observed between the determined. This paper studied the implementation of the Ensemble Kalman Filter Square Root (EnKF-SR) method in nonlinear model of the steam drum boiler equation. The computation to estimate the height of water level and the temperature of steam was by simulation using Matlab software. Thus an error was observed between the determined water level and the steam temperature, and that of estimated water level and steam temperature. The result of simulation by Ensemble Kalman Filter Square Root (EnKF-SR) on the nonlinear model of steam drum boiler showed that the error was less than 2%. The implementation of EnKF-SR on the steam drum boiler r model comprises of three simulations, each of which generates 200, 300 and 400 ensembles. The best simulation exhibited the error between the real condition and the estimated result, by generating 400 ensemble. The simulation in water level in order of 0.00002145 m, whereas in the steam temperature was some 0.00002121 kelvin.

The Isolation of Nanofibre Cellulose from Oil Palm Empty Fruit Bunch Via Steam Explosion and Hydrolysis with HCl 10%

NASA Astrophysics Data System (ADS)

Gea, S.; Zulfahmi, Z.; Yunus, D.; Andriayani, A.; Hutapea, Y. A.

2018-03-01

Cellulose nanofibrils were obtained from oil palm empty fruit bunch using steam explosion and hydrolized with 10% solution of HCl. Steam explosion coupled with acid hydrolysis pretreatment on the oil palm empty fruit bunch was very effective in the depolymerization and defibrillation process of the fibre to produce fibers in nanodimension. Structural analysis of steam exploded fibers was determined by Fourier Transform Infrared (FT-IR) spectroscopy. Thermal stability of cellulose measured using image analysis software image J. Characterization of the fibers by TEM and SEM displayed that fiber diameter decreases with mechanical-chemical treatment and final nanofibril size was 20-30 nm. FT-IR and TGA data confirmed the removal of hemicellulose and lignin during the chemical treatment process.

A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

PubMed

Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

2015-12-01

The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

A computational approach to real-time image processing for serial time-encoded amplified microscopy

NASA Astrophysics Data System (ADS)

Oikawa, Minoru; Hiyama, Daisuke; Hirayama, Ryuji; Hasegawa, Satoki; Endo, Yutaka; Sugie, Takahisa; Tsumura, Norimichi; Kuroshima, Mai; Maki, Masanori; Okada, Genki; Lei, Cheng; Ozeki, Yasuyuki; Goda, Keisuke; Shimobaba, Tomoyoshi

2016-03-01

High-speed imaging is an indispensable technique, particularly for identifying or analyzing fast-moving objects. The serial time-encoded amplified microscopy (STEAM) technique was proposed to enable us to capture images with a frame rate 1,000 times faster than using conventional methods such as CCD (charge-coupled device) cameras. The application of this high-speed STEAM imaging technique to a real-time system, such as flow cytometry for a cell-sorting system, requires successively processing a large number of captured images with high throughput in real time. We are now developing a high-speed flow cytometer system including a STEAM camera. In this paper, we describe our approach to processing these large amounts of image data in real time. We use an analog-to-digital converter that has up to 7.0G samples/s and 8-bit resolution for capturing the output voltage signal that involves grayscale images from the STEAM camera. Therefore the direct data output from the STEAM camera generates 7.0G byte/s continuously. We provided a field-programmable gate array (FPGA) device as a digital signal pre-processor for image reconstruction and finding objects in a microfluidic channel with high data rates in real time. We also utilized graphics processing unit (GPU) devices for accelerating the calculation speed of identification of the reconstructed images. We built our prototype system, which including a STEAM camera, a FPGA device and a GPU device, and evaluated its performance in real-time identification of small particles (beads), as virtual biological cells, owing through a microfluidic channel.

[Steam cautery of the cornea in microbial keratitis].

PubMed

Maier, P; Birnbaum, F; Reinhard, T

2008-01-01

In some cases topical antimicrobial treatment of microbial keratitis or corneal ulcers remains unsuccessful, with increasing infiltration of the corneal stroma. In this situation the steam cautery procedure developed by Karl Wessely in 1911 can lead to rapid healing of the inflammatory process, avoiding further corneal surgery. In this article we describe the steam cautery technique and discuss its indications for microbial keratitis.

A Fresnel collector process heat experiment at Capitol Concrete Products

NASA Technical Reports Server (NTRS)

Hauger, J. S.

1981-01-01

An experiment is planned, conducted and evaluated to determine the feasibility of using a Power Kinetics' Fresnel concentrator to provide process heat in an industrial environment. The plant provides process steam at 50 to 60 psig to two autoclaves for curing masonry blocks. When steam is not required, the plant preheats hot water for later use. A second system is installed at the Jet Propulsion Laboratory parabolic dish test site for hardware validation and experiment control. Experiment design allows for the extrapolation of results to varying demands for steam and hot water, and includes a consideration of some socio-technical factors such as the impact on production scheduling of diurnal variations in energy availability.

[Steam and air co-injection in removing TCE in 2D-sand box].

PubMed

Wang, Ning; Peng, Sheng; Chen, Jia-Jun

2014-07-01

Steam and air co-injection is a newly developed and promising soil remediation technique for non-aqueous phase liquids (NAPLs) in vadose zone. In this study, in order to investigate the mechanism of the remediation process, trichloroethylene (TCE) removal using steam and air co-injection was carried out in a 2-dimensional sandbox with different layered sand structures. The results showed that co-injection perfectly improved the "tailing" effect compared to soil vapor extraction (SVE), and the remediation process of steam and air co-injection could be divided into SVE stage, steam strengthening stage and heat penetration stage. Removal ratio of the experiment with scattered contaminant area was higher and removal speed was faster. The removal ratios from the two experiments were 93.5% and 88.2%, and the removal periods were 83.9 min and 90.6 min, respectively. Steam strengthened the heat penetration stage. The temperature transition region was wider in the scattered NAPLs distribution experiment, which reduced the accumulation of TCE. Slight downward movement of TCE was observed in the experiment with TCE initially distributed in a fine sand zone. And such downward movement of TCE reduced the TCE removal ratio.

Quality comparison of continuous steam sterilization segmented-flow aseptic processing versus conventional canning of whole and sliced mushrooms.

PubMed

Anderson, N M; Walker, P N

2011-08-01

This study was carried out to investigate segmented-flow aseptic processing of particle foods. A pilot-scale continuous steam sterilization unit capable of producing shelf stable aseptically processed whole and sliced mushrooms was developed. The system utilized pressurized steam as the heating medium to achieve high temperature-short time processing conditions with high and uniform heat transfer that will enable static temperature penetration studies for process development. Segmented-flow technology produced a narrower residence time distribution than pipe-flow aseptic processing; thus, whole and sliced mushrooms were processed only as long as needed to achieve the target F₀  = 7.0 min and were not overcooked. Continuous steam sterilization segmented-flow aseptic processing produced shelf stable aseptically processed mushrooms of superior quality to conventionally canned mushrooms. When compared to conventionally canned mushrooms, aseptically processed yield (weight basis) increased 6.1% (SD = 2.9%) and 6.6% (SD = 2.2%), whiteness (L) improved 3.1% (SD = 1.9%) and 4.7% (SD = 0.7%), color difference (ΔE) improved 6.0% (SD = 1.3%) and 8.5% (SD = 1.5%), and texture improved 3.9% (SD = 1.7%) and 4.6% (SD = 4.2%), for whole and sliced mushrooms, respectively. Segmented-flow aseptic processing eliminated a separate blanching step, eliminated the unnecessary packaging of water and promoted the use of bag-in-box and other versatile aseptic packaging methods. Segmented-flow aseptic processing is capable of producing shelf stable aseptically processed particle foods of superior quality to a conventionally canned product. This unique continuous steam sterilization process eliminates the need for a separate blanching step, reduces or eliminates the need for a liquid carrier, and promotes the use of bag-in-box and other versatile aseptic packaging methods. © 2011 Institute of Food Technologists®

Chlor-Alkali Technology.

ERIC Educational Resources Information Center

Venkatesh, S.; Tilak, B. V.

1983-01-01

Chlor-alkali technology is one of the largest electrochemical industries in the world, the main products being chlorine and caustic soda (sodium hydroxide) generated simultaneously by the electrolysis of sodium chloride. This technology is reviewed in terms of electrochemical principles and manufacturing processes involved. (Author/JN)

Production cost comparisons of hydrogen from fossil and nuclear fuel and water decomposition

NASA Technical Reports Server (NTRS)

Ekman, K. R.

1981-01-01

The comparative costs entailed in producing hydrogen by major technologies that rely on petroleum, natural gas, coal, thermochemical cycles, and electrolysis are examined. Techniques were developed for comparing these processes by formulating the process data and economic assessments on a uniform and consistent basis. These data were normalized to permit a meaningful comparative analysis of product costs of these processes.

High School Students' Proficiency and Confidence Levels in Displaying Their Understanding of Basic Electrolysis Concepts

ERIC Educational Resources Information Center

Sia, Ding Teng; Treagust, David F.; Chandrasegaran, A. L.

2012-01-01

This study was conducted with 330 Form 4 (grade 10) students (aged 15-16 years) who were involved in a course of instruction on electrolysis concepts. The main purposes of this study were (1) to assess high school chemistry students' understanding of 19 major principles of electrolysis using a recently developed 2-tier multiple-choice diagnostic…

Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

PubMed

Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

2014-08-01

A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electrolysis treatment of trichiasis by using ultra-fine needle.

PubMed

Sakarya, Yasar; Sakarya, Rabia; Yildirim, Aydin

2010-01-01

To determine the safety and efficacy of electrolysis treatment of trichiasis by using ultrafine needle. The medical records of 24 lids of 24 patients who underwent electrolysis treatment for trichiasis by the same surgeon (Y.S.) during the period from May 2006 through December 2008 were reviewed. The average age of the 24 patients was 59.2 years (range, 43 to 76 years). Thirteen of the patients were women. The results were considered satisfactory if no recurrence of trichiasis occurred for at least 6 months after the last electrolysis procedure. Sixteen of the 24 patients (66.6%) had a satisfactory result with 1 treatment. Of the 8 patients (33.3%) who had an unsatisfactory result, while 5 (20.8%) responded well to 1 additional electrolysis, 3 (12.5%) responded well to 2 additional electrolyses to the recurrent cilia. The procedure was well tolerated by the patients. All eyelids healed within 2 weeks after treatment without any scarring. Faint hypopigmentation was visible in 2 patients (8.3%). Mild notching of eyelid occurred in 4 patients (16.6%). Electrolysis treatment by using ultrafine (55-microm thickness) needle is an effective and safe method for treatment of trichiasis with many advantages over other recognized modalities of therapy.

Electrolysis of plutonium nitride in LiCl-KCl eutectic melts

NASA Astrophysics Data System (ADS)

Shirai, O.; Iwai, T.; Shiozawa, K.; Suzuki, Y.; Sakamura, Y.; Inoue, T.

2000-01-01

The electrolysis of plutonium nitride, PuN, was investigated in the LiCl-KCl eutectic salt with 0.54 wt% PuCl 3 at 773 K in order to understand the dissolution of PuN at the anode and the deposition of metal at the cathode from the viewpoint of the application of a pyrochemical process to nitride fuel cycle. It was found from cyclic voltammetry that the electrochemical dissolution of PuN began nearly at the theoretically evaluated potential and this reaction was irreversible. Several grams of plutonium metal were successfully recovered at the molybdenum electrode as a deposit with a current efficiency of about 90%, although some fractions of the deposited plutonium often fell from the molybdenum electrode.

Bioelectrochemical oxidation of water.

PubMed

Pita, Marcos; Mate, Diana M; Gonzalez-Perez, David; Shleev, Sergey; Fernandez, Victor M; Alcalde, Miguel; De Lacey, Antonio L

2014-04-23

The electrolysis of water provides a link between electrical energy and hydrogen, a high energy density fuel and a versatile energy carrier, but the process is very expensive. Indeed, the main challenge is to reduce energy consumption for large-scale applications using efficient renewable catalysts that can be produced at low cost. Here we present for the first time that laccase can catalyze electrooxidation of H2O to molecular oxygen. Native and laboratory-evolved laccases immobilized onto electrodes serve as bioelectrocatalytic systems with low overpotential and a high O2 evolution ratio against H2O2 production during H2O electrolysis. Our results open new research ground on H2O splitting, as they overcome serious practical limitations associated with artificial electrocatalysts currently used for O2 evolution.

40 CFR Table 1 to Subpart Ddddd of... - Emission Limits for New or Reconstructed Boilers and Process Heaters

Code of Federal Regulations, 2013 CFR

2013-07-01

.... HCl 2.2E-02 lb per MMBtu of heat input 2.5E-02 lb per MMBtu of steam output or 0.28 lb per MWh For... basis corrected to 3 percent oxygen, 30-day rolling average) 1.2E-01 lb per MMBtu of steam output or 1.5... per MMBtu of steam output or 4.2E-01 lb per MWh; or (2.7E-05 lb per MMBtu of steam output or 3.7E-04...

40 CFR 61.305 - Reporting and recordkeeping.

Code of Federal Regulations, 2012 CFR

2012-07-01

... unit or process heater with a design heat input capacity of 44 MW (150 × 106 BTU/hr) or greater is used... or other flare design (i.e., steam-assisted, air-assisted or nonassisted), all visible emission... temperature of the steam generating unit or process heater with a design heat input capacity of less than 44...

40 CFR 61.305 - Reporting and recordkeeping.

Code of Federal Regulations, 2014 CFR

2014-07-01

... unit or process heater with a design heat input capacity of 44 MW (150 × 106 BTU/hr) or greater is used... or other flare design (i.e., steam-assisted, air-assisted or nonassisted), all visible emission... temperature of the steam generating unit or process heater with a design heat input capacity of less than 44...

40 CFR 61.305 - Reporting and recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... unit or process heater with a design heat input capacity of 44 MW (150 × 106 BTU/hr) or greater is used... or other flare design (i.e., steam-assisted, air-assisted or nonassisted), all visible emission... temperature of the steam generating unit or process heater with a design heat input capacity of less than 44...

40 CFR 61.305 - Reporting and recordkeeping.

Code of Federal Regulations, 2013 CFR

2013-07-01

... unit or process heater with a design heat input capacity of 44 MW (150 × 106 BTU/hr) or greater is used... or other flare design (i.e., steam-assisted, air-assisted or nonassisted), all visible emission... temperature of the steam generating unit or process heater with a design heat input capacity of less than 44...

40 CFR 61.305 - Reporting and recordkeeping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... unit or process heater with a design heat input capacity of 44 MW (150 × 106 BTU/hr) or greater is used... or other flare design (i.e., steam-assisted, air-assisted or nonassisted), all visible emission... temperature of the steam generating unit or process heater with a design heat input capacity of less than 44...

Microbial safety and overall quality of cantaloupe fresh-cut pieces prepared from whole cantaloupe after wet steam treatment

USDA-ARS?s Scientific Manuscript database

Fresh-cut cantaloupes have been associated with outbreaks of Salmonelosis disease and the minimally processed fresh-cut fruits have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. In this study, we evaluated the effect of minimal wet steam t...

Progress in ethanol production from corn kernel by applying cooking pre-treatment.

PubMed

Voca, Neven; Varga, Boris; Kricka, Tajana; Curic, Duska; Jurisic, Vanja; Matin, Ana

2009-05-01

In order to improve technological properties of corn kernel for ethanol production, samples were treated with a hydrothermal pre-treatment of cooking (steaming), prior to drying. Two types of cooking process parameters were applied; steam pressure of 0.5 bars during a 10 min period, and steam pressure of 1.5 bars during a 30 min period. Afterwards, samples were dried at four different temperatures, 70, 90, 110 and 130 degrees C. Control sample was also submitted to the aforementioned drying parameters. Since the results showed that starch utilization, due to the gelatinization process, was considerably higher in the samples pre-treated before the ethanol production process, it was found that the cooking treatment had a positive effect on ethanol yield from corn kernel. Therefore, the highest ethanol yield was found in the corn kernel samples cooked for 30 min at steam pressure 1.5 bars and dried at 130 degrees C. Due to the similarity of processes used for starch fermentation, introduction of cooking pre-treatment will not significantly increase the overall ethanol production costs, whereas it will result in significantly higher ethanol yield.

DATA QUALITY OBJECTIVES FOR SELECTING WASTE SAMPLES FOR BENCH-SCALE REFORMER TREATABILITY STUDIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

BANNING DL

2011-02-11

This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Bench-Scale Reforming testing. The type, quantity, and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluidized bed steam reformer. A determination of the adequacy of the fluidized bed steam reformer process to treat Hanford tank waste is required.more » The initial step in determining the adequacy of the fluidized bed steam reformer process is to select archived waste samples from the 222-S Laboratory that will be used in a bench scale tests. Analyses of the selected samples will be required to confirm the samples meet the shipping requirements and for comparison to the bench scale reformer (BSR) test sample selection requirements.« less

Effect of Steam Deactivation Severity of ZSM-5 Additives on LPG Olefins Production in the FCC Process.

PubMed

Gusev, Andrey A; Psarras, Antonios C; Triantafyllidis, Konstantinos S; Lappas, Angelos A; Diddams, Paul A

2017-10-21

ZSM-5-containing catalytic additives are widely used in oil refineries to boost light olefin production and improve gasoline octanes in the Fluid Catalytic Cracking (FCC) process. Under the hydrothermal conditions present in the FCC regenerator (typically >700 °C and >8% steam), FCC catalysts and additives are subject to deactivation. Zeolites (e.g., Rare Earth USY in the base catalyst and ZSM-5 in Olefins boosting additives) are prone to dealumination and partial structural collapse, thereby losing activity, micropore surface area, and undergoing changes in selectivity. Fresh catalyst and additives are added at appropriate respective levels to the FCC unit on a daily basis to maintain overall targeted steady-state (equilibrated) activity and selectivity. To mimic this process under accelerated laboratory conditions, a commercial P/ZSM-5 additive was hydrothermally equilibrated via a steaming process at two temperatures: 788 °C and 815 °C to simulate moderate and more severe equilibration industrial conditions, respectively. n -Dodecane was used as probe molecule and feed for micro-activity cracking testing at 560 °C to determine the activity and product selectivity of fresh and equilibrated P-doped ZSM-5 additives. The fresh/calcined P/ZSM-5 additive was very active in C 12 cracking while steaming limited its activity, i.e., at catalyst-to-feed (C/F) ratio of 1, about 70% and 30% conversion was obtained with the fresh and steamed additives, respectively. A greater activity drop was observed upon increasing the hydrothermal deactivation severity due to gradual decrease of total acidity and microporosity of the additives. However, this change in severity did not result in any selectivity changes for the LPG (liquefied petroleum gas) olefins as the nature (Brønsted-to-Lewis ratio) of the acid/active sites was not significantly altered upon steaming. Steam deactivation of ZSM-5 had also no significant effect on aromatics formation which was enhanced at higher conversion levels. Coke remained low with both fresh and steam-deactivated P/ZSM-5 additives.

Feasibility of Using an Electrolysis Cell for Quantification of the Electrolytic Products of Water from Gravimetric Measurement

PubMed Central

2018-01-01

A gravimetric method for the quantitative assessment of the products of electrolysis of water is presented. In this approach, the electrolysis cell was directly powered by 9 V batteries. Prior to electrolysis, a known amount of potassium hydrogen phthalate (KHP) was added to the cathode compartment, and an excess amount of KHCO3 was added to the anode compartment electrolyte. During electrolysis, cathode and anode compartments produced OH−(aq) and H+(aq) ions, respectively. Electrolytically produced OH−(aq) neutralized the KHP, and the completion of this neutralization was detected by a visual indicator color change. Electrolytically produced H+(aq) reacted with HCO3 −(aq) liberating CO2(g) from the anode compartment. Concurrent liberation of H2(g) and O2(g) at the cathode and anode, respectively, resulted in a decrease in the mass of the cell. Mass of the electrolysis cell was monitored. Liberation of CO2(g) resulted in a pronounced effect of a decrease in mass. Experimentally determined decrease in mass (53.7 g/Faraday) agreed with that predicted from Faraday's laws of electrolysis (53.0 g/Faraday). The efficacy of the cell was tested to quantify the acid content in household vinegar samples. Accurate results were obtained for vinegar analysis with a precision better than 5% in most cases. The cell offers the advantages of coulometric method and additionally simplifies the circuitry by eliminating the use of a constant current power source or a coulometer. PMID:29629210

Feasibility of Using an Electrolysis Cell for Quantification of the Electrolytic Products of Water from Gravimetric Measurement.

PubMed

Melaku, Samuel; Gebeyehu, Zewdu; Dabke, Rajeev B

2018-01-01

A gravimetric method for the quantitative assessment of the products of electrolysis of water is presented. In this approach, the electrolysis cell was directly powered by 9 V batteries. Prior to electrolysis, a known amount of potassium hydrogen phthalate (KHP) was added to the cathode compartment, and an excess amount of KHCO 3 was added to the anode compartment electrolyte. During electrolysis, cathode and anode compartments produced OH - (aq) and H + (aq) ions, respectively. Electrolytically produced OH - (aq) neutralized the KHP, and the completion of this neutralization was detected by a visual indicator color change. Electrolytically produced H + (aq) reacted with HCO 3 - (aq) liberating CO 2 (g) from the anode compartment. Concurrent liberation of H 2 (g) and O 2 (g) at the cathode and anode, respectively, resulted in a decrease in the mass of the cell. Mass of the electrolysis cell was monitored. Liberation of CO 2 (g) resulted in a pronounced effect of a decrease in mass. Experimentally determined decrease in mass (53.7 g/Faraday) agreed with that predicted from Faraday's laws of electrolysis (53.0 g/Faraday). The efficacy of the cell was tested to quantify the acid content in household vinegar samples. Accurate results were obtained for vinegar analysis with a precision better than 5% in most cases. The cell offers the advantages of coulometric method and additionally simplifies the circuitry by eliminating the use of a constant current power source or a coulometer.

A novel cleaning process for industrial production of xylose in pilot scale from corncob by using screw-steam-explosive extruder.

PubMed

Zhang, Hong-Jia; Fan, Xiao-Guang; Qiu, Xue-Liang; Zhang, Qiu-Xiang; Wang, Wen-Ya; Li, Shuang-Xi; Deng, Li-Hong; Koffas, Mattheos A G; Wei, Dong-Sheng; Yuan, Qi-Peng

2014-12-01

Steam explosion is the most promising technology to replace conventional acid hydrolysis of lignocellulose for biomass pretreatment. In this paper, a new screw-steam-explosive extruder was designed and explored for xylose production and lignocellulose biorefinery at the pilot scale. We investigated the effect of different chemicals on xylose yield in the screw-steam-explosive extrusion process, and the xylose production process was optimized as followings: After pre-impregnation with sulfuric acid at 80 °C for 3 h, corncob was treated at 1.55 MPa with 9 mg sulfuric acid/g dry corncob (DC) for 5.5 min, followed by countercurrent extraction (3 recycles), decoloration (activated carbon dosage 0.07 g/g sugar, 75 °C for 40 min), and ion exchange (2 batches). Using this process, 3.575 kg of crystal xylose was produced from 22 kg corncob, almost 90 % of hemicellulose was released as monomeric sugar, and only a small amount of by-products was released (formic acid, acetic acid, fural, 5-hydroxymethylfurfural, and phenolic compounds were 0.17, 1.14, 0.53, 0.19, and 1.75 g/100 g DC, respectively). All results indicated that the screw-steam-explosive extrusion provides a more effective way to convert hemicellulose into xylose and could be an alternative method to traditional sulfuric acid hydrolysis process for lignocellulose biorefinery.

Pilot-scale steam aging of steel slags.

PubMed

Kumar, Praveen; Satish Kumar, D; Marutiram, K; Prasad, Smr

2017-06-01

Solid waste management has gained importance in the steel industry in view of rising environmental concerns and scarcity of raw materials. In spite of significant developments in reducing waste generation and development of recycling technologies, steel slag is still a concern for the industry as most of it is dumped. Steel slag is similar to stone aggregates in strength, but its volumetric instability in contact with water hinders its application as aggregates in construction. A part of steel slag is normally exposed to rain and sun for natural aging and stabilization for months before use. The natural aging process is slow and time-consuming, and thus restricts its usage. The steelmaking slag can be put to effective use as coarse aggregates if quickly aged and stabilized by pre-reacting the free expansive phases. In the present work, a new process has been developed to accelerate the steel slag aging process using steam in a 30 T pilot scale facility. The setup has controlled steam injection, distribution, and process control system for steam, temperature, flow, and pressure. Steam percolates through the minute pores in the slag lumps and hydrates the expansive free lime and MgO phases, making it stable. The aged slag expansion properties were tested using an in-house developed expansion testing apparatus. The process is capable of reducing the expansion of steel slag from 3.5% to <1.5% (standard requirement) in 7 days. The aged steel slag is currently being used in roads at JSW Steel, Vijayanagar Works.

Optimization of electrocoagulation process to treat grey wastewater in batch mode using response surface methodology.

PubMed

Karichappan, Thirugnanasambandham; Venkatachalam, Sivakumar; Jeganathan, Prakash Maran

2014-01-10

Discharge of grey wastewater into the ecological system causes the negative impact effect on receiving water bodies. In this present study, electrocoagulation process (EC) was investigated to treat grey wastewater under different operating conditions such as initial pH (4-8), current density (10-30 mA/cm2), electrode distance (4-6 cm) and electrolysis time (5-25 min) by using stainless steel (SS) anode in batch mode. Four factors with five levels Box-Behnken response surface design (BBD) was employed to optimize and investigate the effect of process variables on the responses such as total solids (TS), chemical oxygen demand (COD) and fecal coliform (FC) removal. The process variables showed significant effect on the electrocoagulation treatment process. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were developed in order to study the electrocoagulation process statistically. The optimal operating conditions were found to be: initial pH of 7, current density of 20 mA/cm2, electrode distance of 5 cm and electrolysis time of 20 min. These results indicated that EC process can be scale up in large scale level to treat grey wastewater with high removal efficiency of TS, COD and FC.

Performance evaluation of a bipolar electrolysis/electrocoagulation (EL/EC) reactor to enhance the sludge dewaterability.

PubMed

Gharibi, Hamed; Sowlat, Mohammad Hossein; Mahvi, Amir Hossein; Keshavarz, Morteza; Safari, Mohammad Hossein; Lotfi, Saeedeh; Bahram Abadi, Mahnaz; Alijanzadeh, Azim

2013-01-01

The present study aimed to evaluate the performance of a bipolar electrolysis/electrocoagulation reactor designed to enhance the sludge dewaterability. The reactor was 15 L in volume, with two series of plates used in it; Ti/RuO(2) plates for the electrolysis of the sludge, and also aluminum and iron plates for electrocoagulation process. The dewaterability of the sludge was determined in terms of its capillary suction time (CST) and specific resistance to filtration (SRF), while the degree of sludge disintegration was determined based on the value of degree of sludge disintegration (DD(SCOD)). The maximum reduction in CST and SRF was observed at a detention time of 20 min and a voltage of 30 V. However, increasing of both detention time and voltage significantly increased the values of CST and SRF even to an extent that they both exceeded those of the untreated sludge. The optimal degree of sludge disintegration achieved by the present study was 2.5%, which was also achieved at a detention time of 20 min and a voltage of 30V. As reported previously, increased DD(SCOD) values led to increasing CST and SRF values, due primarily to the disruption of the sludge flocs. According to the results from the present study, it can be concluded that simultaneous application of electrocoagulation and electrolysis is effective in enhancing the sludge dewaterability, because electrocoagulation helps to achieve a higher degree of sludge disintegration while maintaining the desired sludge dewaterability. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhanced decolorization of azo dye in a small pilot-scale anaerobic baffled reactor coupled with biocatalyzed electrolysis system (ABR-BES): a design suitable for scaling-up.

PubMed

Cui, Dan; Guo, Yu-Qi; Lee, Hyung-Sool; Wu, Wei-Min; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

2014-07-01

A four-compartment anaerobic baffled reactor (ABR) incorporated with membrane-less biocatalyzed electrolysis system (BES) was tested for the treatment of azo dye (alizarin yellow R, AYR) wastewater (AYR, 200 mg L(-1); glucose, 1000 mg L(-1)). The ABR-BES was operated without and with external power supply to examine AYR reduction process and reductive intermediates with different external voltages (0.3, 0.5 and 0.7 V) and hydraulic retention times (HRT: 8, 6 and 4h). The decolorization efficiency in the ABR-BES (8h HRT, 0.5 V) was higher than that in ABR-BES without electrolysis, i.e. 95.1 ± 1.5% versus 86.9 ± 6.3%. Incorporation of BES with ABR accelerated the consumption of VFAs (mainly acetate) and attenuated biogas (methane) production. Higher power supply (0.7 V) enhanced AYR decolorization efficiency (96.4 ± 1.8%), VFAs removal, and current density (24.1 Am(-3) TCV). Shorter HRT increased volumetric AYR decolorization rates, but decreased AYR decolorization efficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis.

PubMed

Tao, Hu-Chun; Lei, Tao; Shi, Gang; Sun, Xiao-Nan; Wei, Xue-Yan; Zhang, Li-Juan; Wu, Wei-Min

2014-01-15

Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10h at initial pH 1.0. It was confirmed that the removal of heavy metals from fly ash leachate with the combination of BESs and ER is feasible. The metal removal efficiency was achieved at 98.5%, 95.4% and 98.1% for Cu(II), Zn(II), and Pb(II), respectively. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that Cu(II) was reduced and recovered mainly as metal Cu on cathodes related to power production, while Zn(II) and Pb(II) were not spontaneously reduced in BESs without applied voltage and basically electrolyzed in the electrolysis reactors. Copyright © 2013 Elsevier B.V. All rights reserved.

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis.

PubMed

Read, Tania L; Macpherson, Julie V

2016-01-06

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp(2) carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail.

Treatment of proximal hamstring tendinopathy-related sciatic nerve entrapment: presentation of an ultrasound-guided "Intratissue Percutaneous Electrolysis" application.

PubMed

Mattiussi, Gabriele; Moreno, Carlos

2016-01-01

Proximal Hamstring Tendinopathy-related Sciatic Nerve Entrapment (PHTrSNE) is a neuropathy caused by fibrosis interposed between the semimembranosus tendon and the sciatic nerve, at the level of the ischial tuberosity. Ultrasound-guided Intratissue Percutaneous Electrolysis (US-guided EPI) involves galvanic current transfer within the treatment target tissue (fibrosis) via a needle 0.30 to 0.33 mm in diameter. The galvanic current in a saline solution instantly develops the chemical process of electrolysis, which in turn induces electrochemical ablation of fibrosis. In this article, the interventional procedure is presented in detail, and both the strengths and limits of the technique are discussed. US-guided EPI eliminates the fibrotic accumulation that causes PHTrSNE, without the semimembranosus tendon or the sciatic nerve being directly involved during the procedure. The technique is however of limited use in cases of compression neuropathy. US-guided EPI is a technique that is quick to perform, minimally invasive and does not force the patient to suspend their activities (work or sports) to make the treatment effective. This, coupled to the fact that the technique is generally well-tolerated by patients, supports use of US-guided EPI in the treatment of PHTrSNE.

Reductive dehalogenation of haloacetic acids by hemoglobin-loaded carbon nanotube electrode.

PubMed

Li, Yu-Ping; Cao, Hong-Bin; Zhang, Yi

2007-01-01

Hemoglobin (Hb) was immobilized on carbon nanotube (CNT) electrode to catalyze the dehalogenation of haloacetic acids (HAAs). FTIR and UV measurements were performed to investigate the activity-keep of Hb after immobilization on CNT. The electrocatalytic behaviors of the Hb-loaded electrode for the dehalogenation of HAAs were studied by cyclic voltammmetry and constant-potential electrolysis technique. An Hb-loaded packed-bed flow reactor was also constructed for bioelectrocatalytic dehalogenation of HAAs. The results showed that Hb retained its nature, the essential features of its native secondary structure, and its biocatalytic activity after immobilization on CNT. Chloroacetic acids and bromoacetic acids could be dehalogenated completely with Hb catalysis through a stepwise dehalogenation process at -0.400V (vs. saturated calomel electrode (SCE)) and -0.200V (vs. SCE), respectively. The removal of 10.5mM trichloroacetic acid and dichloroacetic acid is ca. 97% and 63%, respectively, with electrolysis for 300min at -0.400V (vs. SCE) using the Hb-loaded packed-bed flow reactor, and almost 100% of tribromoacetic acid and dibromoacetic acid was removed with electrolysis for 40min at -0.200V (vs. SCE). The average current efficiency of Hb-catalytic dehalogenation almost reaches 100%.

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

PubMed Central

Read, Tania L.; Macpherson, Julie V.

2016-01-01

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail. PMID:26779959

Effect of nitro substituent on electrochemical oxidation of phenols at boron-doped diamond anodes.

PubMed

Jiang, Yi; Zhu, Xiuping; Li, Hongna; Ni, Jinren

2010-02-01

In order to investigate nitro-substitutent's effect on degradation of phenols at boron-doped diamond (BDD) anodes, cyclic voltammetries of three nitrophenol isomers: 2-nitrophenol (2NP), 3-nitrophenol (3NP) and 4-nitrophenol (4NP) were studied, and their bulk electrolysis results were compared with phenol's (Ph) under alkaline condition. The voltammetric study showed nitrophenols could be attacked by hydroxyl radicals and nitro-group was released from the aromatic ring. Results of bulk electrolysis showed degradation of all phenols were fit to a pseudo first-order equation and followed in this order: 2NP>4NP>3NP>Ph. Molecular structures, especially carbon atom charge, significantly influenced the electrochemical oxidation of these isomers. Intermediates were analyzed during the electrolysis process, and were mainly catechol, resorcinol, hydroquinone, and carboxylic acids, such as acetic acid and oxalic acid. A simple degradation pathway was proposed. Moreover, a linear increasing relationship between degradation rates and Hammett constants of the studied phenols was observed, which demonstrated that electrochemical oxidation of these phenols was mainly initiated by electrophilic attack of hydroxyl radicals at BDD anodes. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Case study on the orientation of phaco hand pieces during steam sterilization processes.

PubMed

van Doornmalen Gomez Hoyos, J P C M; van Wezel, R A C; van Doornmalen, H W J M

2015-05-01

Steam sterilization is an essential part of infection prevention. The literature shows that sterilization of medical instruments containing channels is not trivial. Phaco hand pieces have a simple configuration: a device contains a channel with a constant radius. No literature was found indicating whether the sterilization conditions on the inner surface of a phaco hand piece are influenced by the orientation of the hand piece. To determine whether the orientation of a phaco hand piece influences the results of a sterilization process of this device. A qualitative case study, including experiments, is performed with a protocolled combination of steam sterilizer, process, phaco hand piece, orientation of the phaco hand piece, and wrapping. In this specific case, the orientation of the hand piece influenced the result of the steam sterilization process; in vertically (upright) oriented phaco hand pieces with free water drainage, sterilization conditions are reproducibly established. In the same process, in horizontally oriented or vertically oriented hand pieces without free drainage, these conditions are not established in a reproducible way. In the investigated combination of sterilizer, process, load, loading pattern and wrapping, phaco hand pieces have to be oriented vertically (upright) with free water drainage to obtain steam sterilization conditions on the inner surface. It is likely that instruments with comparable configuration and dimensions will yield comparable results. It is therefore recommended that this issue is considered during the development of medical instruments and during performance qualifications of such instruments. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Fabrication of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using electrolysis plasma treatment

NASA Astrophysics Data System (ADS)

Meng, Jianbing; Dong, Xiaojuan; Wei, Xiuting; Yin, Zhanmin

2015-04-01

An anti-adhesion surface with a water contact angle of 167° was fabricated on aluminium samples of rubber plastic moulds by electrolysis plasma treatment using mixed electrolytes of C6H5O7(NH4)3 and Na2SO4, followed by fluorination. To optimise the fabrication conditions, several important processing parameters such as the discharge voltage, discharge time, concentrations of supporting electrolyte and stearic acid ethanol solution were examined systematically. Using scanning electron microscopy (SEM) to analyse surfaces morphology, micrometer scale pits, and protrusions were found on the surface, with numerous nanometer mastoids contained in the protrusions. These binary micro/nano-scale structures, which are similar to the micro-structures of soil-burrowing animals, play a critical role in achieving low adhesion properties. Otherwise, the anti-adhesion behaviours of the resulting samples were analysed by the atomic force microscope (AFM), Fourier-transform infrared spectrophotometer (FTIR), electrons probe micro-analyzer (EPMA), optical contact angle meter, digital Vickers microhardness (Hv) tester, and electronic universal testing. The results show that the electrolysis plasma treatment does not require complex processing parameters, using a simple device, and is an environment-friendly and effective method. Under the optimised conditions, the contact angle (CA) for the modified anti-adhesion surface is up to 167°, the sliding angle (SA) is less than 2°, roughness of the sample surface is only 0.409μm. Moreover, the adhesion force and Hv are 0. 9KN and 385, respectively.

Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes.

PubMed

Daghrir, Rimeh; Drogui, Patrick; Tshibangu, Joel; Delegan, Nazar; El Khakani, My Ali

2014-05-01

The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H2O2) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H2O2 (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8%, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9%, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9 ± 2 and 85.5 ± 2 %, whereas 70% of total organic carbon removal was achieved.

Using Mole Ratios of Electrolytic Products of Water for Analysis of Household Vinegar: An Experiment for the Undergraduate Physical Chemistry Laboratory

ERIC Educational Resources Information Center

Dabke, Rajeev B.; Gebeyehu, Zewdu

2012-01-01

A simple 3-h physical chemistry undergraduate experiment for the quantitative analysis of acetic acid in household vinegar is presented. The laboratory experiment combines titration concept with electrolysis and an application of the gas laws. A vinegar sample was placed in the cathode compartment of the electrolysis cell. Electrolysis of water…

Water electrolysis system refurbishment and testing

NASA Technical Reports Server (NTRS)

Greenough, B. M.

1972-01-01

The electrolytic oxygen generator for the back-up water electrolysis system in a 90-day manned test was refurbished, improved and subjected to a 182-day bench test. The performance of the system during the test demonstrated the soundness of the basic electrolysis concept, the high development status of the automatic controls which allowed completely hands-off operation, and the capability for orbital operation. Some design improvements are indicated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lower, Mark D; Christopher, Timothy W; Oland, C Barry

The Facilities and Operations (F&O) Directorate is sponsoring a continuous process improvement (CPI) program. Its purpose is to stimulate, promote, and sustain a culture of improvement throughout all levels of the organization. The CPI program ensures that a scientific and repeatable process exists for improving the delivery of F&O products and services in support of Oak Ridge National Laboratory (ORNL) Management Systems. Strategic objectives of the CPI program include achieving excellence in laboratory operations in the areas of safety, health, and the environment. Identifying and promoting opportunities for achieving the following critical outcomes are important business goals of the CPImore » program: improved safety performance; process focused on consumer needs; modern and secure campus; flexibility to respond to changing laboratory needs; bench strength for the future; and elimination of legacy issues. The Steam Pressure-Reducing Station (SPRS) Safety and Energy Efficiency Improvement Project, which is under the CPI program, focuses on maintaining and upgrading SPRSs that are part of the ORNL steam distribution network. This steam pipe network transports steam produced at the ORNL steam plant to many buildings in the main campus site. The SPRS Safety and Energy Efficiency Improvement Project promotes excellence in laboratory operations by (1) improving personnel safety, (2) decreasing fuel consumption through improved steam system energy efficiency, and (3) achieving compliance with applicable worker health and safety requirements. The SPRS Safety and Energy Efficiency Improvement Project being performed by F&O is helping ORNL improve both energy efficiency and worker safety by modifying, maintaining, and repairing SPRSs. Since work began in 2006, numerous energy-wasting steam leaks have been eliminated, heat losses from uninsulated steam pipe surfaces have been reduced, and deficient pressure retaining components have been replaced. These improvements helped ORNL reduce its overall utility costs by decreasing the amount of fuel used to generate steam. Reduced fuel consumption also decreased air emissions. These improvements also helped lower the risk of burn injuries to workers and helped prevent shrapnel injuries resulting from missiles produced by pressurized component failures. In most cases, the economic benefit and cost effectiveness of the SPRS Safety and Energy Efficiency Improvement Project is reflected in payback periods of 1 year or less.« less

Ultrasound-Guided Application of Percutaneous Electrolysis as an Adjunct to Exercise and Manual Therapy for Subacromial Pain Syndrome: a Randomized Clinical Trial.

PubMed

de-Miguel-Valtierra, Lorena; Salom-Moreno, Jaime; Fernández-de-Las-Peñas, César; Cleland, Joshua A; Arias-Buría, José L

2018-05-16

This randomized clinical trial compared the effects of adding US-guided percutaneous electrolysis into a program consisting of manual therapy and exercise on pain, related-disability, function and pressure sensitivity in subacromial pain syndrome. Fifty patients with subacromial pain syndrome were randomized into manual therapy and exercise or percutaneous electrolysis group. All patients received the same manual therapy and exercise program, one session per week for 5 consecutive weeks. Patients assigned to the electrolysis group also received the application of percutaneous electrolysis at each session. The primary outcome was Disabilities of the Arm, Shoulder and Hand (DASH). Secondary outcomes included pain, function (Shoulder Pain and Disability Index-SPADI) pressure pain thresholds (PPTs) and Global Rating of Change (GROC). They were assessed at baseline, post-treatment, and 3, and 6 months after treatment. Both groups showed similar improvements in the primary outcome (DASH) at all follow-ups (P=0.051). Subjects receiving manual therapy, exercise, and percutaneous electrolysis showed significantly greater changes in shoulder pain (P<0.001) and SPADI (P<0.001) than those receiving manual therapy and exercise alone at all follow-ups. Effect sizes were large (SMD>0.91) for shoulder pain and function at 3 and 6 months in favour of the percutaneous electrolysis group. No between-groups differences in PPT were found. The current clinical trial found that the inclusion of US-guided percutaneous electrolysis in combination with manual therapy and exercise resulted in no significant differences for related-disability (DASH) than the application of manual therapy and exercise alone in patients with subacromial pain syndrome. Nevertheless, differences were reported for some secondary outcomes such as shoulder pain and function (SPADI). Whether or not these effects are reliable should be addressed in future studies Perspective This study found that the inclusion of US-guided percutaneous electrolysis into a manual therapy and exercise program resulted in no significant differences for disability and pressure pain sensitivity than the application of manual therapy and exercise alone in patients with subacromial pain syndrome. Copyright © 2018. Published by Elsevier Inc.

Advanced Water Purification System for In Situ Resource Utilization

NASA Technical Reports Server (NTRS)

Anthony, Stephen M.; Jolley, Scott T.; Captain, James G.

2013-01-01

A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extraterrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtration material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removal technique. Our studies have shown a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

Design of a water electrolysis flight experiment

NASA Technical Reports Server (NTRS)

Lee, M. Gene; Grigger, David J.; Thompson, C. Dean; Cusick, Robert J.

1993-01-01

Supply of oxygen (O2) and hydrogen (H2) by electolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missios. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. The Electrolysis Performance Improvement Concept Study (EPICS) flight experiment described herein is sponsored by NASA Headquarters as a part of the In-Space Technology Experiment Program (IN-STEP). The objective of the EPICS is to further contribute to the improvement of the SEF technology, specifially by demonstrating and validating the SFE electromechanical process in microgravity as well as investigating perrformance improvements projected possible in a microgravity environment. This paper defines the experiment objective and presents the results of the preliminary design of the EPICS. The experiment will include testing three subscale self-contained SFE units: one containing baseline components, and two units having variations in key component materials. Tests will be conducted at varying current and thermal condition.

Advanced Water Purification System for In Situ Resource Utilization Project

NASA Technical Reports Server (NTRS)

Anthony, Stephen M.

2014-01-01

A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extratrrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtrtion material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removable technique. Our studies have show a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

Novel integrated electrodialysis/electro-oxidation process for the efficient degradation of 2,4-dichlorophenoxyacetic acid.

PubMed

Raschitor, A; Llanos, J; Cañizares, P; Rodrigo, M A

2017-09-01

This work presents a novel approach of wastewater treatment technology that consists of a combined electrodialysis/electro-oxidation process, specially designed to allow increasing the efficiency in the oxidation of ionic organic pollutants contained in diluted waste. Respect to conventional electrolysis, the pollutant is simultaneously concentrated and oxidized, enhancing the performance of the cell due to the higher concentration achieved in the nearness of the anode. A proof of concept is tested with the ionic pesticide 2,4-D (2,4-dichlorophenoxyacetic acid) and results show that the efficiency of this new technology overcomes that electrolysis by more than double, regardless the supporting electrolyte used (either NaCl or Na 2 SO 4 ). Moreover, the removal rate of 2,4-D when using NaCl was found to be more efficient, due to the best performance of the electrode material selected (DSA ® ) towards the formation of oxidants in chloride supporting electrolyte. These results open the way for overcoming the efficiency limitations of electrochemical treatment processes for the treatment of solutions with low concentrated ionic pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Downhole steam generator using low pressure fuel and air supply

DOEpatents

Fox, Ronald L.

1983-01-01

An apparatus for generation of steam in a borehole for penetration into an earth formation wherein a spiral, tubular heat exchanger is used in the combustion chamber to isolate the combustion process from the water being superheated for conversion into steam. The isolation allows combustion of a relatively low pressure oxidant and fuel mixture for generating high enthalpy steam. The fuel is preheated by feedback of combustion gases from the top of the combustion chamber through a fuel preheater chamber. The hot exhaust gases of combustion at the bottom of the combustion chamber, after flowing over the heat exchanger enter an exhaust passage and pipe. The exhaust pipe is mounted inside the water supply line heating the water flowing into the heat exchanger. After being superheated in the heat exchanger, the water is ejected through an expansion nozzle and converts into steam prior to penetration into the earth formation. Pressure responsive doors are provided at a steam outlet downstream of the nozzle and close when the steam pressure is lost due to flameout.

Apparent Km of mitochondria for oxygen computed from Vmax measured in permeabilized muscle fibers is lower in water enriched in oxygen by electrolysis than injection

PubMed Central

Zoll, Joffrey; Bouitbir, Jamal; Sirvent, Pascal; Klein, Alexis; Charton, Antoine; Jimenez, Liliana; Péronnet, François R; Geny, Bernard; Richard, Ruddy

2015-01-01

Background It has been suggested that oxygen (O2) diffusion could be favored in water enriched in O2 by a new electrolytic process because of O2 trapping in water superstructures (clathrates), which could reduce the local pressure/content relationships for O2 and facilitate O2 diffusion along PO2 gradients. Materials and methods Mitochondrial respiration was compared in situ in saponin-skinned fibers isolated from the soleus muscles of Wistar rats, in solution enriched in O2 by injection or the electrolytic process 1) at an O2 concentration decreasing from 240 µmol/L to 10 µmol/L (132 mmHg to 5 mmHg), with glutamate–malate or N, N, N′, N′-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)–ascorbate (with antimycin A) as substrates; and 2) at increasing adenosine diphosphate (ADP) concentration with glutamate–malate as substrate. Results As expected, maximal respiration decreased with O2 concentration and, when compared to glutamate–malate, the apparent Km O2 of mitochondria for O2 was significantly lower with TMPD–ascorbate with both waters. However, when compared to the water enriched in O2 by injection, the Km O2 was significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters. Conclusion In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process. PMID:26203225

Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs.

PubMed

Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

2014-01-01

Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply.

Apparent Km of mitochondria for oxygen computed from Vmax measured in permeabilized muscle fibers is lower in water enriched in oxygen by electrolysis than injection.

PubMed

Zoll, Joffrey; Bouitbir, Jamal; Sirvent, Pascal; Klein, Alexis; Charton, Antoine; Jimenez, Liliana; Péronnet, François R; Geny, Bernard; Richard, Ruddy

2015-01-01

It has been suggested that oxygen (O2) diffusion could be favored in water enriched in O2 by a new electrolytic process because of O2 trapping in water superstructures (clathrates), which could reduce the local pressure/content relationships for O2 and facilitate O2 diffusion along PO2 gradients. Mitochondrial respiration was compared in situ in saponin-skinned fibers isolated from the soleus muscles of Wistar rats, in solution enriched in O2 by injection or the electrolytic process 1) at an O2 concentration decreasing from 240 µmol/L to 10 µmol/L (132 mmHg to 5 mmHg), with glutamate-malate or N, N, N', N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)-ascorbate (with antimycin A) as substrates; and 2) at increasing adenosine diphosphate (ADP) concentration with glutamate-malate as substrate. As expected, maximal respiration decreased with O2 concentration and, when compared to glutamate-malate, the apparent Km O2 of mitochondria for O2 was significantly lower with TMPD-ascorbate with both waters. However, when compared to the water enriched in O2 by injection, the Km O2 was significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters. In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process.

Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs

PubMed Central

Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

2014-01-01

Background Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Methods Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Results Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. Conclusions In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply. PMID:25210438

Processing Maple Syrup with a Vapor Compression Distiller: An Economic Analysis

Treesearch

Lawrence D. Garrett

1977-01-01

A test of vapor compression distillers for processing maple syrup revealed that: (1) vapor compression equipment tested evaporated 1 pound of water with .047 pounds of steam equivalent (electrical energy); open-pan evaporators of similar capacity required 1.5 pounds of steam equivalent (oil energy) to produce 1 pound of water; (2) vapor compression evaporation produced...

Extraction and recovery of pectic fragments from citrus processing waste for co-production with ethanol

USDA-ARS?s Scientific Manuscript database

Steam treatment of citrus processing waste (CPW) at 160°C followed by a rapid decompression (steam explosion) at either pH 2.8 or 4.5 provides an efficient and rapid fragmentation of protopectin in CPW and renders a large fraction of fragmented pectins, arabinans, galactans and arabinogalactans solu...

Application of electrolysis to inactivation of antibacterials in clinical use.

PubMed

Nakano, Takashi; Hirose, Jun; Kobayashi, Toyohide; Hiro, Naoki; Kondo, Fumitake; Tamai, Hiroshi; Tanaka, Kazuhiko; Sano, Kouichi

2013-04-01

Contamination of surface water by antibacterial pharmaceuticals (antibacterials) from clinical settings may affect aquatic organisms, plants growth, and environmental floral bacteria. One of the methods to decrease the contamination is inactivation of antibacterials before being discharged to the sewage system. Recently, we reported the novel method based on electrolysis for detoxifying wastewater containing antineoplastics. In the present study, to clarify whether the electrolysis method is applicable to the inactivation of antibacterials, we electrolyzed solutions of 10 groups of individual antibacterials including amikacin sulfate (AMK) and a mixture (MIX) of some commercial antibacterials commonly prescribed at hospitals, and measured their antibacterial activities. AMK was inactivated in its antibacterial activities and its concentration decreased by electrolysis in a time-dependent manner. Eighty to ninety-nine percent of almost all antibacterials and MIX were inactivated within 6h of electrolysis. Additionally, cytotoxicity was not detected in any of the electrolyzed solutions of antibacterials and MIX by the Molt-4-based cytotoxicity test. Copyright © 2012 Elsevier Inc. All rights reserved.

Acceleration Techniques for Recombination of Gases in Electrolysis Microactuators with Nafion®-Coated Electrocatalyst

PubMed Central

Sheybani, Roya; Meng, Ellis

2015-01-01

Recombination of electrolysis gases (oxidation of hydrogen and reduction of oxygen) is an important factor in operation efficiency of devices employing electrolysis such as actuators and also unitized regenerative fuel cells. Several methods of improving recombination speed and repeatability were developed for application to electrolysis microactuators with Nafion®-coated catalytic electrodes. Decreasing the electrolysis chamber volume increased the speed, consistency, and repeatability of the gas recombination rate. To further improve recombination performance, methods to increase the catalyst surface area, hydrophobicity, and availability were developed and evaluated. Of these, including in the electrolyte pyrolyzed-Nafion®-coated Pt segments contained in the actuator chamber accelerated recombination by increasing the catalyst surface area and decreasing the gas transport diffusion path. This approach also reduced variability in recombination encountered under varying actuator orientation (resulting in differing catalyst/gas bubble proximity) and increased the rate of recombination by 2.3 times across all actuator orientations. Repeatability of complete recombination for different generated gas volumes was studied through cycling. PMID:26251561

Photocatalytic activity and reusability of ZnO layer synthesised by electrolysis, hydrogen peroxide and heat treatment.

PubMed

Akhmal Saadon, Syaiful; Sathishkumar, Palanivel; Mohd Yusoff, Abdull Rahim; Hakim Wirzal, Mohd Dzul; Rahmalan, Muhammad Taufiq; Nur, Hadi

2016-08-01

In this study, the zinc oxide (ZnO) layer was synthesised on the surface of Zn plates by three different techniques, i.e. electrolysis, hydrogen peroxide and heat treatment. The synthesised ZnO layers were characterised using scanning electron microscopy, X-ray diffraction, UV-visible diffuse reflectance and photoluminescence spectroscopy. The photocatalytic activity of the ZnO layer was further assessed against methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB was achieved up to 84%, 79% and 65% within 1 h for ZnO layers synthesised by electrolysis, heat and hydrogen peroxide treatment, respectively. The reusability results show that electrolysis and heat-treated ZnO layers have considerable photocatalytic stability. Furthermore, the results confirmed that the photocatalytic efficiency of ZnO was directly associated with the thickness and enlarged surface area of the layer. Finally, this study proved that the ZnO layers synthesised by electrolysis and heat treatment had shown better operational stability and reusability.

The Application of Electrolysis Method to Reduce Ammonia Content in Liquid Waste of Tofu

NASA Astrophysics Data System (ADS)

Prabowo, S.; Nurlaili; Muflihah; Tindangen, R. A.; Sukemi

2018-04-01

Ammonia (NH3) is known as an important chemical in industrial sector. It is also known as harmful pollutant. Ammonia is a weak base, a gas in room temperature and has 330°C of BP. The aims of research were to investigate the effect of voltage (4 to 12 volt), time (1 to 30 min.), concentration of ammonia (0.01 to 0.05 M) and potassium hydroxide concentration on the ammonia content in aqueous solution by using electrolysis method with platinum as electrodes. The ammonia content was analysed by using UV-Vis spectrophotometer. The result showed that an increment in the voltage, time and potassium hydroxide concentration could increase the amount of converted ammonia. The optimum condition to reduce the ammonia content by using electrolysis method was 10 V of electrical voltage, 25 min. of electrolysis time and 0.04 M of potassium hydroxide concentration. At the optimum condition, the electrolysis method could decrease 81.13% of ammonia content in liquid waste of tofu.

A novel nano-Ni/SiO2 catalyst for hydrogen production from steam reforming of ethanol.

PubMed

Wu, Chunfei; Williams, Paul T

2010-08-01

Catalytic steam reforming of ethanol has been regarded as a promising way to produce hydrogen. However, catalytic deactivation is a key problem in the process. In this paper, a novel nano-Ni/SiO2 catalyst was prepared by a simple sol-gel method and compared to catalysts prepared by an impregnation method in relation to the steam reforming ethanol process. Good Ni dispersion and high BET surface areas (>700 m2 g(-1)) were obtained for sol-gel catalysts, whereas only 1 m2 g(-1) surface area was obtained for the Ni/SiO2 impregnation catalyst. The results of catalytic steam reforming of ethanol showed that about twice of the hydrogen production was produced with the Ni/SiO2 catalyst prepared by sol-gel (around 0.2 g h(-1)) compared with that prepared by impregnation (around 0.1 g h(-1)). The analysis of the used catalysts showed that 10Ni/SiO2-B and 20Ni/SiO2-B presented the highest stability, while other catalysts were fragmented into small pieces after the reforming process, especially the catalysts prepared by impregnation. A novel catalyst has been produced that has been shown to be effective in the production of hydrogen from the steam reforming of ethanol.

Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

PubMed Central

Arias-Buría, José L.; Truyols-Domínguez, Sebastián; Valero-Alcaide, Raquel; Salom-Moreno, Jaime; Atín-Arratibel, María A.; Fernández-de-las-Peñas, César

2015-01-01

Objective. To compare effects of ultrasound- (US-) guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n = 17) group or exercise (n = 19) group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions). Shoulder pain (NPRS) and disability (DASH) were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P < 0.01): individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention. PMID:26649058

Tension-Enhanced Hydrogen Evolution Reaction on Vanadium Disulfide Monolayer

NASA Astrophysics Data System (ADS)

Pan, Hui

2016-02-01

Water electrolysis is an efficient way for hydrogen production. Finding efficient, cheap, and eco-friendly electrocatalysts is essential to the development of this technology. In the work, we present a first-principles study on the effects of tension on the hydrogen evolution reaction of a novel electrocatalyst, vanadium disulfide (VS2) monolayer. Two electrocatalytic processes, individual and collective processes, are investigated. We show that the catalytic ability of VS2 monolayer at higher hydrogen coverage can be efficiently improved by escalating tension. We find that the individual process is easier to occur in a wide range of hydrogen coverage and the collective process is possible at a certain hydrogen coverage under the same tension. The best hydrogen evolution reaction with near-zero Gibbs free energy can be achieved by tuning tension. We further show that the change of catalytic activity with tension and hydrogen coverage is induced by the change of free carrier density around the Fermi level, that is, higher carrier density, better catalytic performance. It is expected that tension can be a simple way to improve the catalytic activity, leading to the design of novel electrocatalysts for efficient hydrogen production from water electrolysis.

Treatment of oilfield produced water by anaerobic process coupled with micro-electrolysis.

PubMed

Li, Gang; Guo, Shuhai; Li, Fengmei

2010-01-01

Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand (five-day) (BODs)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the effect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.

La0.8Sr0.2Co0.8Ni0.2O3-δ impregnated oxygen electrode for H2O/CO2 co-electrolysis in solid oxide electrolysis cells

NASA Astrophysics Data System (ADS)

Zheng, Haoyu; Tian, Yunfeng; Zhang, Lingling; Chi, Bo; Pu, Jian; Jian, Li

2018-04-01

High-temperature H2O/CO2 co-electrolysis through reversible solid oxide electrolysis cell (SOEC) provides potentially a feasible and eco-friendly way to convert electrical energy into chemicals stored in syngas. In this work, La0.8Sr0.2Co0.8Ni0.2O3-δ (LSCN) impregnated Gd0.1Ce0.9O1.95 (GDC)-(La0.8Sr0.2)0.95MnO3-δ (LSM) composite oxygen electrode is studied as high-performance electrode for H2O/CO2 co-electrolysis. The LSCN impregnated cell exhibits competitive performance with the peak power density of 1057 mW cm-2 at 800 °C in solid oxide fuel cell (SOFC) mode; in co-electrolysis mode, the current density can reach 1.60 A cm-2 at 1.5 V at 800 °C with H2O/CO2 ratio of 2/1. With LSCN nanoparticles dispersed on the surface of GDC-LSM to maximize the reaction active sites, the LSCN impregnated cell shows significant enhanced electrochemical performance at both SOEC and SOFC modes. The influence of feed gas composition (H2O-H2-CO2) and operating voltages on the performance of co-electrolysis are discussed in detail. The cell shows a very stable performance without obvious degradation for more than 100 h. Post-test characterization is analyzed in detail by multiple measurements.

Catalyst and process development for the H/sub 2/ preparation from future fuel cell feedstocks. Quarterly progress report, October 1, 1978-December 31, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarrington, R M; Feins, I R; Hwang, H S

1979-01-01

The work done under this contract in the last quarter of 1978 was concerned with Phase I, which involved preliminary catalyst and process evaluation. The processes under study are hydrogen assisted steam reforming (HASR), catalytic partial oxidation (CPO), and autothermal steam reforming (ATR). Existing Engelhard test units were modified to carry out preliminary runs using the first two processes. Technical analysis to support work in this area consisted of heat and material balances constrained by equilibrium considerations. In a third task, the steam reforming of methanol to produce hydrogen was studied over two commercial low-temperature shift catalysts. Aging runs indicatedmore » good initial performance on both catalysts, but methanol conversion started to decline after a few hundred hours on stream.« less

Spiral inlets for steam turbines

NASA Astrophysics Data System (ADS)

Škach, Radek; Uher, Jan

2017-09-01

This paper deals with the design process of special nozzle blades for spiral inlets. Spiral inlets are used for the first stages of high pressure and intermediate pressure steam turbines with both reaction and impulse blades when throttling or sliding pressure control is applied. They improve the steam flow uniformity from the inlet pipe and thus decrease the aerodynamic losses. The proposed evaluation of the inlet angle is based on the free vortex law.

Imitative modeling automatic system Control of steam pressure in the main steam collector with the influence on the main Servomotor steam turbine

NASA Astrophysics Data System (ADS)

Andriushin, A. V.; Zverkov, V. P.; Kuzishchin, V. F.; Ryzhkov, O. S.; Sabanin, V. R.

2017-11-01

The research and setting results of steam pressure in the main steam collector “Do itself” automatic control system (ACS) with high-speed feedback on steam pressure in the turbine regulating stage are presented. The ACS setup is performed on the simulation model of the controlled object developed for this purpose with load-dependent static and dynamic characteristics and a non-linear control algorithm with pulse control of the turbine main servomotor. A method for tuning nonlinear ACS with a numerical algorithm for multiparametric optimization and a procedure for separate dynamic adjustment of control devices in a two-loop ACS are proposed and implemented. It is shown that the nonlinear ACS adjusted with the proposed method with the regulators constant parameters ensures reliable and high-quality operation without the occurrence of oscillations in the transient processes the operating range of the turbine loads.

Hockey-stick steam generator for LMFBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallinan, G.J.; Svedlund, P.E.

1981-01-01

This paper presents the criteria and evaluation leading to the selection of the Hockey Stick Steam Generator Concept and subsequent development of that concept for LMFBR application. The selection process and development of the Modular Steam Generator (MSG) is discussed, including the extensive test programs that culminated in the manufacture and test of a 35 MW(t) Steam Generator. The design of the CRBRP Steam Generator is described, emphasizing the current status and a review of the critical structural areas. CRBRP steam generator development tests are evaluated, with a discussion of test objectives and rating of the usefulness of test resultsmore » to the CRBRP prototype design. Manufacturing experience and status of the CRBRP prototype and plant units is covered. The scaleup of the Hockey Stick concept to large commercial plant application is presented, with an evaluation of scaleup limitations, transient effects, and system design implications.« less

Experimental Study of Hydroxy Gas (HHO) Production with Variation in Current, Voltage and Electrolyte Concentration

NASA Astrophysics Data System (ADS)

Alam, Noor; Pandey, K. M.

2017-08-01

In this paper, work has been carried out experimentally for the investigation of the effects of variation incurrent, voltage, temperature, chemical concentration and reaction time on the amount of hydroxy gas produced. Further effects on the overall electrolysis efficiency of advance alkaline water is also studied. The hydroxy gas (HHO) has been produced experimentally by the electrolysis of alkaline water with parallel plate electrode of 316L-grade stainless steel. The electrode has been selected on the basis of corrosion resistance and inertness with respect to electrolyte (KOH). The process used for the production of HHO is conventional as compared to the other production processes because of reduced energy consumption, less maintenance and low setup cost. From the experimental results, it has been observed that with increase in voltage, temperature and electrolyte concentration of alkaline solution, the production of hydroxy gas has increased about 30 to 40% with reduction in electrical energy consumption.

Chemicals and ruminant feed from lignocelluloses by the steaming-extraction process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puls, J.; Ayla, C.; Dietrichs, H.H.

1983-01-01

Steaming is applicable to lignocelluloses with lower lignin content such as hardwoods and most agricultural residues. The cellulose of steamed fiber materials becomes accessible for enzymatic degradation in spite of the presence of lignin. The hemicelluloses become water soluble. The lignin can be extracted with alkaline or organic solvents. Without further treatment, the steamed material can be used as highly digestible ruminant feed. Steam treatment, however, is most effective after separation of the hemicelluloses. Depending on the starting material, 10-25% hemicelluloses with xylose contents up to 80% can be recovered by aqueous extraction of the fiber material. The xylans andmore » xylan fragments can be used as substrates for chemical, biochemical, or microbial processes. The residual fiber material consists only of cellulose and lignin in highly accessible form for rumen bacteria and fungal cellulases. They are digested by ruminants up to 70-80% and degraded by cellulases without further treatment to 50-60%. In a second extraction step, the lignin can be removed from the fiber material. After controlled steaming at 190/sup 0/C with an optimum yield of hemicellulose, two-thirds of the original lignin present in the starting material can be extracted with dilute alkali. A relatively mild steaming with additional alkaline extraction of lignin is recommended when total utilization of the components including the hemicelluloses is desired. The extracted lignin can be used as a chemical feedstock. 16 references, 6 figures, 3 tables.« less

Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production.

PubMed

Gwak, Jieun; Choun, Myounghoon; Lee, Jaeyoung

2016-02-19

Ammonia is beginning to attract a great deal of attention as an alternative energy source carrier, because clean hydrogen can be produced through electrolytic processes without the emission of COx . In this study, we deposited various shapes of Pt catalysts under potentiostatic mode; the electrocatalytic oxidation behavior of ammonia using these catalysts was studied in alkaline media. The electrodeposited Pt was characterized by both qualitative and quantitative analysis. To discover the optimal structure and the effect of ammonia concentration, the bulk pH value, reaction temperature, and applied current of ammonia oxidation were investigated using potential sweep and galvanostatic methods. Finally, ammonia electrolysis was conducted using a zero-gap cell, producing highly pure hydrogen with an energy efficiency over 80 %. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Removal Efficiency of Electrocoagulation Treatment Using Aluminium Electrode for Stabilized Leachate

NASA Astrophysics Data System (ADS)

Mohamad Zailani, L. W.; Amdan, N. S. Mohd; Zin, N. S. M.

2018-04-01

This research was conducted to investigate the performance of aluminium electrode in electrocoagulation process removing chemical oxygen demand (COD), ammonia, turbidity, colour and suspended solid (SS) from Simpang Renggam landfill leachate. Effects of current density, electrolysis duration and pH were observed in this study. From the data obtained, optimum condition at current density was recorded at 200 A/m2with the electrolysis duration of 20-minutes and optimum pH value at 4. The removal recorded at this condition for COD, ammonia, colour, turbidity and suspended solid were 60%, 37%, 94%, 88% and 89% respectively. Electrocoagulation treatment give a better result and can be applied for leachate treatment in future. Thus, electrocoagulation treatment has the potential to be used in treatment of leachate.

Electrochemical Coupling of Biomass-Derived Acids: New C8 Platforms for Renewable Polymers and Fuels.

PubMed

Wu, Linglin; Mascal, Mark; Farmer, Thomas J; Arnaud, Sacha Pérocheau; Wong Chang, Maria-Angelica

2017-01-10

Electrolysis of biomass-derived carbonyl compounds is an alternative to condensation chemistry for supplying products with chain length >C 6 for biofuels and renewable materials production. Kolbe coupling of biomass-derived levulinic acid is used to obtain 2,7-octanedione, a new platform molecule only two low process-intensity steps removed from raw biomass. Hydrogenation to 2,7-octanediol provides a chiral secondary diol largely unknown to polymer chemistry, whereas intramolecular aldol condensation followed by hydrogenation yields branched cycloalkanes suitable for use as high-octane, cellulosic gasoline. Analogous electrolysis of an itaconic acid-derived methylsuccinic monoester yields a chiral 2,5-dimethyladipic acid diester, another underutilized monomer owing to lack of availability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of contact glow discharge electrolysis method for degradation of batik dye waste Remazol Red by the addition of Fe2+ ion

NASA Astrophysics Data System (ADS)

Saksono, Nelson; Puspita, Indah; Sukreni, Tulus

2017-03-01

Contact Glow Discharge Electrolysis (CGDE) has been shown to degrade much weight organic compounds such as dyes because the production of hydroxil radical (•OH) is excess. This research aims to degrade batik dye waste Remazol Red, using CGDE method with the addition of Fe2+ ion. The addition of iron salt compounds has proven to increase process efficiency. Dye degradation is known by measure its absorbances with Spectrophotometer UV-Vis. The result of study showed that percentage degradation was 99.92% in 20 minutes which obtained by using Na2SO4 0.01 M, with addition FeSO4 0,1 gram, applied voltage 860 volt, and 1 wolfram anode 5 mm depth.

Multifactorial modelling of high-temperature treatment of timber in the saturated water steam medium

NASA Astrophysics Data System (ADS)

Prosvirnikov, D. B.; Safin, R. G.; Ziatdinova, D. F.; Timerbaev, N. F.; Lashkov, V. A.

2016-04-01

The paper analyses experimental data obtained in studies of high-temperature treatment of softwood and hardwood in an environment of saturated water steam. Data were processed in the Curve Expert software for the purpose of statistical modelling of processes and phenomena occurring during this process. The multifactorial modelling resulted in the empirical dependences, allowing determining the main parameters of this type of hydrothermal treatment with high accuracy.

Failure of non-vacuum steam sterilization processes for dental handpieces.

PubMed

Winter, S; Smith, A; Lappin, D; McDonagh, G; Kirk, B

2017-12-01

Dental handpieces are used in critical and semi-critical operative interventions. Although some dental professional bodies recommend that dental handpieces are sterilized between patient use there is a lack of clarity and understanding of the effectiveness of different steam sterilization processes. The internal mechanisms of dental handpieces contain narrow lumens (0.8-2.3 mm) which can impede the removal of air and ingress of saturated steam required to achieve sterilization conditions. To identify the extent of sterilization failure in dental handpieces using a non-vacuum process. In-vitro and in-vivo investigations were conducted on widely used UK bench-top steam sterilizers and three different types of dental handpieces. The sterilization process was monitored inside the lumens of dental handpieces using thermometric (TM; dataloggers), chemical indicator (CI), and biological indicator (BI) methods. All three methods of assessing achievement of sterility within dental handpieces that had been exposed to non-vacuum sterilization conditions demonstrated a significant number of failures [CI: 8/3024 (fails/no. of tests); BI: 15/3024; TM: 56/56] compared to vacuum sterilization conditions (CI: 2/1944; BI: 0/1944; TM: 0/36). The dental handpiece most likely to fail sterilization in the non-vacuum process was the surgical handpiece. Non-vacuum sterilizers located in general dental practice had a higher rate of sterilization failure (CI: 25/1620; BI: 32/1620; TM: 56/56) with no failures in vacuum process. Non-vacuum downward/gravity displacement, type N steam sterilizers are an unreliable method for sterilization of dental handpieces in general dental practice. The handpiece most likely to fail sterilization is the type most frequently used for surgical interventions. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Industry starts to tap the sun's energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-01-15

The dedication in 1978 of the Riegel Textile Corp's solar-collecting field in La France, South Carolina, marked the first solar process hot water application within the textile industry. Results from this DOE-funded project could provide a breakthrough in the application of solar energy to industrial process hot water, which accounts for about 4% of the nation's energy needs. A General Electric Co. industrial solar process-hot-water system is used to heat water to 190 F in an open fabric-dyeing vat designed to provide from 50 to 70% of the process heat required for a single-dye unit. The largest, citrus-juice processing plantmore » in the world at Bradenton, Florida, is being equipped wth a General Electric solar system that will supply high temperature steam (350 F, 134 psig) to one of the plant's pasteurizers during weekdays. On weekends, the solar unit will supply a major part of the steam used by two of the plant's four glycol-refrigerant dryers. A solar total energy system that will be used to provide electricity, steam, heat, and hot water for a knitware plant in Shenandoah, Georgia, is described. The project, managed by Sandia Laboratory, will utilize two axis parabolic dish solar collectors, which will produce steam at temperatures in the range of 750 F. The system is being designed to provide 60% of the annual energy requirements of the knitware facility. It will provide 35% of the electricity, 60% of the process steam, 98% of the domestic water and space heating needs, and 85% of the air conditioning requirements of the 42,000 sq ft factory being built for the West Germany-based Wilhelm Bleyle Co. (MCW)« less

Oxygen Activation and Photoelectrochemical Oxidation on Oxide Surfaces

DTIC Science & Technology

2013-12-04

electrolysis followed by product determination from mass spectroscopy showed that acetophenone was produced with a 95% Faradaic efficiency. The H/D kinetic...vs. NHE) 10 electrode: scan rate, 100mV/s. (b) Plot of catalytic currents during electrolysis at −1.38 V, icat (background subtracted), vs...controlled potential electrolysis at 3.0 V at two boron doped diamond electrodes (~0.85 cm2). Red line: background current without added catalyst

Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

NASA Technical Reports Server (NTRS)

1975-01-01

Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

The Use of Multi-Reactor Cascade Plasma Electrolysis for Linear Alkylbenzene Sulfonate Degradation

NASA Astrophysics Data System (ADS)

Saksono, Nelson; Ibrahim; Zainah; Budikania, Trisutanti

2018-03-01

Plasma electrolysis is a method that can produce large amounts of hydroxyl radicals to degrade organic waste. The purpose of this study is to improve the effectiveness of Linear alkylbenzene sulfonate (LAS) degradation by using multi-reactor cascade plasma electrolysis. The reactor which operated in circulation system, using 3 reactors series flow and 6 L of LAS with initial concentration of 100 ppm. The results show that the LAS degradation can be improved multi-reactor cascade plasma electrolysis. The greatest LAS degradation is achieved up to 81.91% with energy consumption of 2227.34 kJ/mmol that is obtained during 120 minutes by using 600 Volt, 0.03 M of KOH, and 0.5 cm of the anode depth.

Steam reforming of commercial ultra-low sulphur diesel

NASA Astrophysics Data System (ADS)

Boon, Jurriaan; van Dijk, Eric; de Munck, Sander; van den Brink, Ruud

Two main routes for small-scale diesel steam reforming exist: low-temperature pre-reforming followed by well-established methane steam reforming on the one hand and direct steam reforming on the other hand. Tests with commercial catalysts and commercially obtained diesel fuels are presented for both processes. The fuels contained up to 6.5 ppmw sulphur and up to 4.5 vol.% of biomass-derived fatty acid methyl ester (FAME). Pre-reforming sulphur-free diesel at around 475 °C has been tested with a commercial nickel catalyst for 118 h without observing catalyst deactivation, at steam-to-carbon ratios as low as 2.6. Direct steam reforming at temperatures up to 800 °C has been tested with a commercial precious metal catalyst for a total of 1190 h with two catalyst batches at steam-to-carbon ratios as low as 2.5. Deactivation was neither observed with lower steam-to-carbon ratios nor for increasing sulphur concentration. The importance of good fuel evaporation and mixing for correct testing of catalysts is illustrated. Diesel containing biodiesel components resulted in poor spray quality, hence poor mixing and evaporation upstream, eventually causing decreasing catalyst performance. The feasibility of direct high temperature steam reforming of commercial low-sulphur diesel has been demonstrated.

Sodium Hydroxide Production from Seawater Desalination Brine: Process Design and Energy Efficiency.

PubMed

Du, Fengmin; Warsinger, David M; Urmi, Tamanna I; Thiel, Gregory P; Kumar, Amit; Lienhard V, John H

2018-05-15

The ability to increase pH is a crucial need for desalination pretreatment (especially in reverse osmosis) and for other industries, but processes used to raise pH often incur significant emissions and nonrenewable resource use. Alternatively, waste brine from desalination can be used to create sodium hydroxide, via appropriate concentration and purification pretreatment steps, for input into the chlor-alkali process. In this work, an efficient process train (with variations) is developed and modeled for sodium hydroxide production from seawater desalination brine using membrane chlor-alkali electrolysis. The integrated system includes nanofiltration, concentration via evaporation or mechanical vapor compression, chemical softening, further ion-exchange softening, dechlorination, and membrane electrolysis. System productivity, component performance, and energy consumption of the NaOH production process are highlighted, and their dependencies on electrolyzer outlet conditions and brine recirculation are investigated. The analysis of the process also includes assessment of the energy efficiency of major components, estimation of system operating expense and comparison with similar processes. The brine-to-caustic process is shown to be technically feasible while offering several advantages, that is, the reduced environmental impact of desalination through lessened brine discharge, and the increase in the overall water recovery ratio of the reverse osmosis facility. Additionally, best-use conditions are given for producing caustic not only for use within the plant, but also in excess amounts for potential revenue.

Postfact phenomena of the wet-steam flow electrization in turbines

NASA Astrophysics Data System (ADS)

Tarelin, A. A.

2017-11-01

Physical processes occurring in a turbine with natural electrization of a humidity-steam flow and their effect on efficiency and reliability of the turbine operation has been considered. Causes of the electrical potential occurrence on a rotor shaft are analyzed. The wet steam's electrization exposure on the electrical potential that is one of the major factors of bearings' electroerosion has been demonstrated on the full-scale installation. Hydrogen formation in wheelspace of the turbine as a result of electrochemical processes and electric field exposure of the space charge has been considered. Hydrogen concentration dependence on a volume charge density in the steam flow has been determined. It is stated that the processes occurring behind the final stage of wet-steam turbines are similar to the ones in elaerosol ectrostatic generators. It has been demonstrated that this phenomenon causes the flow's temporal inhibition and starts pulsations. These factors' impact on power loss of the turbine has been evaluated and recommendations for their elimination have been offered. It has been determined that motions of charged drops can cause self-maintained discharges inside of the flow and between the flow and grounded surfaces that are accompanied by electromagnetic radiation of the wide spectrum. The integrated studies have shown that physical phenomena occurring due to natural electrization negatively affect efficiency and reliability of the turbine operation. Practical recommendations allowing one to minimize the negative effects of the flow natural electrization process have been offered.

Students' construction of a simple steam distillation apparatus and development of creative thinking skills: A project-based learning

NASA Astrophysics Data System (ADS)

Diawati, Chansyanah; Liliasari, Setiabudi, Agus; Buchari

2017-05-01

This project-based learning combined the chemistry of separation process using steam distillation with engineering design process in an undergraduate chemistry course. Students built upon their knowledge of phase changes, immiscible mixture, and the relationship between vapor pressure and boiling point to complete a project of modifications steam distillation apparatus. The research method is a qualitative case study, which aims to describe how (1) the creative thinking skills of students emerged during six weeks of theproject, (2) students built steam distillation apparatus characteristics as the project product and (3) students response to the project-based learning model. The results showed that the students had successfully constructed a steam distillation apparatus using plastic kettle as steam generator and distillation flask. A Plastic tubewas used to drain water vapor from steam generator to distillation flask and to drain steam containing essential oil to the condenser. A biscuit tin filled with ice was used as a condenser. The time required until resulting distillate was fifteen minutes. The production of essential was conductive qualitatively by a very strong smell typical of essential oil and two phases of distillate. Throughout the project, students formulated the relevant and varied problem, formulated the goals, proposed the ideas of the apparatus and materials, draw apparatus design, constructed apparatus, tested apparatus, evaluated, and reported the project. Student response was generally positive. They were pleased, interested, more understanding the concepts and work apparatus principles, also implemented new ideas. These results indicate that project-based learning can develop students' creative thinking skills. Based on these results, it is necessary to conduct research and implemented project-based learning to other concepts.

Alteration of biomacromolecule in corn by steam flaking in relation to biodegradation kinetics in ruminant, revealed with vibrational molecular spectroscopy

NASA Astrophysics Data System (ADS)

Xu, Ningning; Liu, Jianxin; Yu, Peiqiang

2018-02-01

Large scale of steam flaked corn has been used in dairy ration to maintain high milk production level. This study aimed to determine effects of steam flaking on processing-induced intrinsic molecular structure changes that were associated with rumen degradation kinetics and nutrients supply. The advanced vibrational molecular spectroscopy was applied to reveal the processing-induced intrinsic structure changes on a molecular basis. The rumen degradation kinetics and nutrient supply were determined using in situ approach in ruminant livestock system. Raw corn grain (RC) and steam flaked corn grain (SFC) were obtained from two different processing plants. The results showed that (1) Compared to RC, SFC had greater truly digestible non-fiber carbohydrate [tdNFC: 86.8 versus 78.0% dry matter (DM)], but lower truly digestible crude protein [tdCP: 7.7 versus 9.0% DM]. (2) The steam flaking increased (P < 0.01) rumen degradable DM (RDDM) and starch (RDSt), but decreased (P < 0.01) rumen degradable protein (RDP). (3) Molecular absorbance intensities of most carbohydrate biopolymers were greater in SFC (P < 0.01), but protein amides associated molecular spectral intensities were lower (P < 0.01) in SFC. (4). The molecular structure and nutrient interactive study showed that carbohydrate spectral intensities were positively (P < 0.10) associated with RDDM and RDSt and protein amide spectral intensities were positively (P < 0.10) associated with RDP. This results indicated that the steam flaking induced molecular structure changes had an interactive relationship with rumen degradation kinetics.

Immediate use steam sterilization: moving beyond current policy.

PubMed

Seavey, Rose

2013-05-01

Immediate-use steam sterilization (IUSS) is steam sterilization intended for immediate use. IUSS may cause an increased risk of infection to patients because of stress and time constraints placed on staff. When IUSS is used, it is vital to properly carry out the complete multistep process according to the manufacturer's written validated instructions for use. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

The Effects of Alarm Display, Processing, and Availability on Crew Performance

DTIC Science & Technology

2000-11-01

snow Instrumentation line leakage Small LOCA Steam generator tube rupture Small feedwater leakage inside containment Cycling of main steam...implemented. • Due to primary pressure controller failure, pressure heater banks cycle between on and off. 8.00 CF1 CF2 CF3 CF4 CF5...temperatures after the high-pressure pre- heaters flows into the steam generators number of active emergency feedwater pumps openings of the condensate

$gamma$-RAY PROCESSING OF RICE. (IV.) STUDIES ON THE AVAILABILITY OF $gamma$-IRRADIATED RICE FOR KOJI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishimura, A.; Takaoka, K.

The availability of rice, gamma -irradiated up to 4.6 x 10/sup 4/ and 3.5 x 10/sup 5/r for koji was studied. The enzyme activities of koji of the steamed samples were stronger than the unirradiated rice in amylase and protease. The sensory test on the once-steamed irradiated rice was almost the same as the twice-steamed unirradiated rice. (OID)

Energy Systems Fabrication Laboratory | Energy Systems Integration Facility

Science.gov Websites

Fabrication The fuel cell fabrication hub includes laboratory spaces with local exhaust and chemical fume hoods that support electrolysis and other chemical process research. Key Infrastructure Perchloric acid washdown hood, local exhaust, specialty gas manifolding, deionized water, chemical fume hoods, glassware

ELECTROCHEMICAL CHROMIC ACID REGENERATION PROCESS: FITTING OF MEMBRANE TRANSPORT PROPERTIES. (R827125)

EPA Science Inventory

Abstract

A mathematical model was developed to predict changes in contaminant concentrations with time, and to estimate contaminant fluxes due to migration, diffusion, and convection in a laboratory-scale batch electrolysis cell for the regeneration of contaminated har...

Electrically conductive diamond electrodes

DOEpatents

Swain, Greg [East Lansing, MI; Fischer, Anne [Arlington, VA; Bennett, Jason [Lansing, MI; Lowe, Michael [Holt, MI

2009-05-19

An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

NASA Astrophysics Data System (ADS)

Graves, Christopher Ronald

Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co-electrolysis of CO2 and H2O to produce syngas (CO/H2 mixture) is identified as a promising method. High temperature electrolysis makes very efficient use of electricity and heat (near-100% electricity-to-syngas efficiency), provides high reaction rates, and the syngas produced can be catalytically converted to hydrocarbons in well-known fuel synthesis reactors (e.g. Fischer-Tropsch). The experimental studies of high temperature electrolysis are made at different scales -- at the cell level, electrode level, and in materials and microstructure development. The results include cell performance and durability, insight into electrode reaction mechanisms, and new high-performance electrode materials. The experimental studies make extensive use of electrochemical impedance spectroscopy and systematic variation of test conditions to examine the electrochemical phenomena. Variation of the material composition itself within families of related materials was an additional parameter used in the electrode level and materials studies that revealed more information than studying a single material would have. Using full cells, the performance and durability of a solid oxide cell applied for co-electrolysis of CO2 and H2O was investigated. High initial performance was observed but the long-term durability needs to be improved. Based on these results, an analysis of the energy balance and economics of an electrolysis-based synthetic fuel production process, including CO2 air capture and Fischer-Tropsch fuel synthesis, determined that the system can feasibly operate at 70% electricity-to-liquid fuel efficiency (higher heating value basis) and that the price of electricity needed to produce competitive synthetic gasoline (at USD2/gal, or 0.53/L, wholesale) is 2-3 U.S. cents per kWh. For 3/gal (0.78/L) gasoline, 4-5 cents per kWh is needed. Fuel production may already be economical in some regions that have inexpensive renewable electricity, such as Iceland. The dominant costs of the process are the electricity cost and the capital cost of the electrolyzer, and this capital cost is significantly increased when operating intermittently (on renewable power sources such as solar and wind). Low cell internal resistance, low degradation, and low manufacturing cost each contribute to a low electrolyzer capital cost, and can be traded off. One straightforward path to affordability is by improving the durability of the high current density cell operation (≥1 A/cm2) that is already possible with these cells. The negative-electrode, a composite of nickel and yttria-stabilized zirconia (YSZ), is often the major site of cell degradation, including in the co-electrolysis results presented here. To better understand the reaction mechanisms at the negative-electrode that limit performance and durability, different metal electrodes including nickel were studied using a simplified point-contact electrode geometry with a well-defined three-phase boundary (TPB; the electrode/electrolyte/gas interface where the electrochemical reactions take place). The simple geometry is useful for isolating the electrochemical properties without the effects of the complex microstructure of technological porous electrodes. Widely different impedance responses of the different metals to the same changes in test conditions (gas composition, temperature, and polarization) were observed, indicating that the same reaction mechanisms are not shared by the different metals, contrary to some recent studies. Evidence was also found that supports the explanation that impurities segregated to the TPB play a major role and are largely responsible for inconsistencies in the electrode kinetics literature. The significance of microstructure at the TPB was also revealed -- the electrode polarization resistance was reduced by an order of magnitude when subjected to extreme conditions of oxidation-reduction and strong cathodic polarization, which induced the formation of a micro/nanostructured TPB. Possible reaction mechanisms for H2O/CO2 reduction and H2/CO oxidation are discussed. Novel ceramic materials based on molybdates with varying Mo valence were synthesized as possible alternative negative-electrode materials. The phase, stability, microstructure and electrical conductivity were characterized. The electrochemical activity for H2O/CO2 reduction and H2/CO oxidation was studied using simplified geometry electrodes, similar to the metals study. Unique phenomena were observed for some of the molybdate materials -- they decomposed into multiple phases and formed a nanostructured surface upon exposure to operating conditions (in certain reducing atmospheres). The new phases and surface features enhanced the electronic conductivity and electrocatalytic activity. Preparing an electrode by performing controlled decomposition to form multiple desirable phases and a desirable microstructure (which can take place in situ) using these materials is a novel way to produce potentially high-performance electrodes for solid oxide cells. By modifying the composition, it was possible to prevent decomposition. Other members of the molybdate family exhibited similarly high electronic conductivity and electrocatalytic activity but did not decompose. The high activity was the result of a different mechanism, probably related to the defect chemistry of the material. The polarization resistances of the best molybdate materials were two orders of magnitude lower than that of donor-doped strontium titanates. Many of the molybdate materials were significantly activated by cathodic polarization, and they exhibited higher performance for cathodic (electrolysis) polarization than anodic (fuel cell) polarization, which makes them especially interesting for use in electrolysis electrodes. Whereas nearly all of the molybdates showed higher performance for H2O electrolysis than CO2 electrolysis, one with vanadium showed nearly equal performance, and a non-molybdate which exhibits some complementary properties to the best molybdates, Gd-doped ceria in nanoparticle form, was found to be an excellent electrocatalyst for CO2 electrolysis and CO oxidation (moreso than for H2O/H2 for which it is known to be good).

Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis.

PubMed

Wang, Hong-Cheng; Cheng, Hao-Yi; Wang, Shu-Sen; Cui, Dan; Han, Jing-Long; Hu, Ya-Ping; Su, Shi-Gang; Wang, Ai-Jie

2016-01-01

In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3%±2.5%, 86.2%±3.8% and 93.5%±1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1%±4.7%, 75.4%±5.0% and 82.1%±2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2%±3.7% and 28.30±1.48 mA, respectively. They were significantly increased to 62.1%±2.0% and 34.55±0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater. Copyright © 2015. Published by Elsevier B.V.

Study on Treatment of Landfill Leachate by Electrochemical, Flocculation and Photocatalysis

NASA Astrophysics Data System (ADS)

Yang, Yue; Jin, Xiuping; Pan, Yunbo; Zuo, Xiaoran

2018-01-01

In this study, the landfill leachate of different seasons in Liaoyang City is as the research object, and COD removal rate is as the main indicator. The electrochemical section’s results show that the optimal treatment conditions for the water of 2016 summer are as follows: voltage is 7.0V, current density is 40.21 A/m2, pH is equal to the raw water, electrolysis time is 1h, and the COD removal rate is 80.41%. The optimal treatment conditions for the 2017 fall’s water are: electrolysis voltage is 7.0 V, current density is 45.06 A/m2, electrolysis time is 4 hours, and COD removal rate is 28.03%. The flow rate of continuous electrolysis is 6.4 L/h using the water of 2016 fall, and the COD removal rate is 10.28%. The results of the flocculation process show that the optimal treatment conditions are as follows: pH is equal to the raw water; the optimal flocculant species is Fe-Al composite flocculant, wherein the optimal ratio of Fe-Al is n (Fe):n (Al)=0.5:1; the best dosage of flocculant is 2.0 g/L and COD removal rate is of 21.11%. The results of photocatalytic show that the optimal conditions are: pH is 4.5, Al2(SO4)3 is 1.0 g/L, FeSO4.7H2O is 700mg/L, H2O2(30%) is 4 mL/L, stirring and standing UV lamp light irradiation 3 hours, and adjusting pH to 6.0 or so, COD removal rate is 36.15%. +

Electrochemical degradation of 5-FU using a flow reactor with BDD electrode: Comparison of two electrochemical systems.

PubMed

Ochoa-Chavez, A S; Pieczyńska, A; Fiszka Borzyszkowska, A; Espinoza-Montero, P J; Siedlecka, E M

2018-06-01

In this study, the electrochemical degradation process of 5-fluorouracil (5-FU) in aqueous media was performed using a continuous flow reactor in an undivided cell (system I), and in a divided cell with a cationic membrane (Nafion ® 424) (system II). In system I, 75% of 5-FU degradation was achieved (50 mg L -1 ) with a applied current density j app  = 150 A m -2 , volumetric flow rate qv = 13 L h -1 , after 6 h of electrolysis (k app  = 0.004 min -1 ). The removal efficiency of 5-FU was higher (95%) when the concentration was 5 mg L -1 under the same conditions. Nitrates (22% of initial amount of N), fluorides (27%) and ammonium (10%) were quantified after 6 h of electrolysis. System II, 77% of 5-FU degradation was achieved (50 mg L -1 ) after 6 h of electrolysis (k app  = 0.004 min -1 ). The degradation rate of 5-FU was complete when the concentration was 5 mg L -1 under the same conditions. Nitrates (29% of initial amount of N), fluorides (25%) and ammonium (5%) were quantified after 6 h of electrolysis. In addition, the main organic byproducts identified by mass spectroscopy were aliphatic compound with carbonyl and carboxyl functionalities. Due to, the mineralization of 5-FU with acceptable efficiency of 88% found in system II (j app of 200 A m -2 ), this system seems to be more promising in the cytostatic drug removal. Moreover the efficiency of 5-FU removal in diluted solutions is better in system II than in system I. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development and demonstration of techniques for reducing occupational radiation doses during refueling outages. Task 1. Steam generator channel head decontamination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abrams, W.T.; Cope, A.W.; Orsulak, R.M.

The overall objective of Task 1 was to demonstrate an effective method for removing tenacious corrosion products in a pressurized water reactor steam generator and thus significantly reduce radiation exposure during subsequent maintenance activities. Various decontamination methods were evaluated and a multistep, low concentration chemical process originated by Kraftwerk Union A.G. (KWU) of the Federal Republic of Germany was selected. The process was further developed and tested by C-E and KWU in West Germany and at C-E's facilities in Windsor, Connecticut. C-E designed, fabricated and tested a portable system to apply the process at Millstone Point II. The decontamination ofmore » the primary channel heads of the two Millstone steam generators was performed by C-E and NUSCO during the 1983 refueling shutdown of Millstone Point II plant. Results of the decontamination were very satisfactory. NUSCO determined that a net savings of 3660 man-rem of personnel exposure was realized during the decontamination demonstration and the subsequent maintenance work on the steam generators.« less

Comparative techno-economic analysis of steam explosion, dilute sulfuric acid, ammonia fiber explosion and biological pretreatments of corn stover.

PubMed

Baral, Nawa Raj; Shah, Ajay

2017-05-01

Pretreatment is required to destroy recalcitrant structure of lignocelluloses and then transform into fermentable sugars. This study assessed techno-economics of steam explosion, dilute sulfuric acid, ammonia fiber explosion and biological pretreatments, and identified bottlenecks and operational targets for process improvement. Techno-economic models of these pretreatment processes for a cellulosic biorefinery of 113.5 million liters butanol per year excluding fermentation and wastewater treatment sections were developed using a modelling software-SuperPro Designer. Experimental data of the selected pretreatment processes based on corn stover were gathered from recent publications, and used for this analysis. Estimated sugar production costs ($/kg) via steam explosion, dilute sulfuric acid, ammonia fiber explosion and biological methods were 0.43, 0.42, 0.65 and 1.41, respectively. The results suggest steam explosion and sulfuric acid pretreatment methods might be good alternatives at present state of technology and other pretreatment methods require research and development efforts to be competitive with these pretreatment methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Demonstration of the production of oxygen-centered free radicals during electrolysis using E.S.R. spin-trapping techniques: effects on cardiac function in the isolated rat heart.

PubMed

Lecour, S; Baouali, A B; Maupoil, V; Chahine, R; Abadie, C; Javouhey-Donzel, A; Rochette, L; Nadeau, R

1998-03-01

The present study was designed to identify the free radicals generated during the electrolysis of the solution used to perfuse isolated rat heart Langendorff preparations. The high reactivity and very short half-life of oxygen free radicals make their detection and identification difficult. A diamagnetic organic molecule (spin trap) can be used to react with a specific radical to produce a more stable secondary radical or "spin adduct" detected by electron spin resonance (ESR). Isovolumic left ventricular systolic pressure (LVSP) and left ventricular end diastolic pressure (LVEDP) were measured by a fluid-filled latex balloon inserted into the left ventricle. The coronary flow was measured by effluent collection. Electrolysis was performed with constant currents of 0.5, 1, 1.5, 3, 5, 7.5, and 10 mA generated by a Grass stimulator and applied to the perfusion solution for 1 min. A group of experiments was done using a 1.5 mA current and a Krebs-Henseleit (K-H) solution containing free radical scavengers (superoxide dismutase (SOD): 100 IU/ml or mannitol: 50 mM). Heart function rapidly declined in hearts perfused with K-H buffer that had been electrolyzed for 1 min. The addition of mannitol (50 mM) to the perfusion solution had no effect on baseline cardiac function before electrolysis while SOD (100 IU/ml) increased the coronary flow. However, SOD was more effective than the mannitol in protecting the heart against decreased of cardiac function, 5 min after the end of electrolysis. Samples of the K-H medium subjected to electrolysis were collected in cuvettes containing a final concentration of 125 mM 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and analyzed by spectroscopy. The ESR spectrum consisted of a quartet signal (hyperfine couplings aN = aH = 14.9 G) originating from the hydroxyl adduct signal, DMPO-OH. The intensity of the DMPO-OH signal remained stable during the 60 s of electrolysis and the quantity of free radicals induced by electrolysis was directly proportional to the intensity of the current. The addition of mannitol and SOD to the perfusate scavenged the hydroxyl radicals present in the solution, suggesting that both hydroxyl and superoxide radicals were formed during electrolysis.

PROCESS OF SEPARATING PLUTONIUM VALUES BY ELECTRODEPOSITION

DOEpatents

Whal, A.C.

1958-04-15

A process is described of separating plutonium values from an aqueous solution by electrodeposition. The process consists of subjecting an aqueous 0.1 to 1.0 N nitric acid solution containing plutonium ions to electrolysis between inert metallic electrodes. A current density of one milliampere io one ampere per square centimeter of cathode surface and a temperature between 10 and 60 d C are maintained. Plutonium is electrodeposited on the cathode surface and recovered.

SISGR-Fundamental Experimental and Theoretical Studies on a Novel Family of Oxide Catalyst Supports for Water Electrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumta, Prashant

2014-10-03

Identification and development of non-noble metal based electro-catalysts or electro-catalysts with significant reduction of expensive noble metal contents (E.g. IrO2, Pt) with comparable electrochemical performance as the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a major breakthrough in the generation of hydrogen by water electrolysis. Accomplishing such a system would not only result reduction of the overall capital costs of PEM based water electrolyzers, but also help attain the targeted hydrogen production cost [< $ 3.0 / gallon gasoline equivalent (gge)] comparable to conventional liquid fuels. In line with these goals, it wasmore » demonstrated that fluorine doped IrO2 thin films and nanostructured high surface area powders display remarkably higher electrochemical activity, and comparable durability as pure IrO2 electro-catalyst for the oxygen evolution reaction (OER) in PEM based water electrolysis. Furthermore, corrosion resistant SnO2 and NbO2 support has been doped with F and coupled with IrO2 or RuO2 for use as an OER electro-catalyst. A solid solution of SnO2:F or NbO2:F with only 20 - 30 mol.% IrO2 or RuO2 yielding a rutile structure in the form of thin films and bulk nanoparticles displays similar electrochemical activity and stability as pure IrO2/RuO2. This would lead to more than 70 mol.% reduction in the noble metal oxide content. Novel nanostructured ternary (Ir,Sn,Nb)O2 thin films of different compositions FUNDAMENTAL STUDY OF NANOSTRUCTURED ELECTRO-CATALYSTS WITH REDUCED NOBLE METAL CONTENT FOR PEM BASED WATER ELECTROLYSIS 4 have also been studied. It has been shown that (Ir0.40Sn0.30Nb0.30)O2 shows similar electrochemical activity and enhanced chemical robustness as compared to pure IrO2. F doping of the ternary (Ir,Sn,Nb)O2 catalyst helps in further decreasing the noble metal oxide content of the catalyst. As a result, these reduced noble metal oxide catalyst systems would potentially be preferred as OER electro-catalysts for PEM electrolysis. The excellent performance of the catalysts coupled with its robustness would make them great candidates for contributing to significant reduction in the overall capital costs of PEM based water electrolyzers. This s.thesis provides a detailed fundamental study of the synthesis, materials, characterization, theoretical studies and detailed electrochemical response and potential mechanisms of these novel electro-catalysts for OER processes.« less

Impact of pretreatment and downstream processing technologies on economics and energy in cellulosic ethanol production.

PubMed

Kumar, Deepak; Murthy, Ganti S

2011-09-05

While advantages of biofuel have been widely reported, studies also highlight the challenges in large scale production of biofuel. Cost of ethanol and process energy use in cellulosic ethanol plants are dependent on technologies used for conversion of feedstock. Process modeling can aid in identifying techno-economic bottlenecks in a production process. A comprehensive techno-economic analysis was performed for conversion of cellulosic feedstock to ethanol using some of the common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. Detailed process models incorporating feedstock handling, pretreatment, simultaneous saccharification and co-fermentation, ethanol recovery and downstream processing were developed using SuperPro Designer. Tall Fescue (Festuca arundinacea Schreb) was used as a model feedstock. Projected ethanol yields were 252.62, 255.80, 255.27 and 230.23 L/dry metric ton biomass for conversion process using dilute acid, dilute alkali, hot water and steam explosion pretreatment technologies respectively. Price of feedstock and cellulose enzymes were assumed as $50/metric ton and 0.517/kg broth (10% protein in broth, 600 FPU/g protein) respectively. Capital cost of ethanol plants processing 250,000 metric tons of feedstock/year was $1.92, $1.73, $1.72 and $1.70/L ethanol for process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Ethanol production cost of $0.83, $0.88, $0.81 and $0.85/L ethanol was estimated for production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Water use in the production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment was estimated 5.96, 6.07, 5.84 and 4.36 kg/L ethanol respectively. Ethanol price and energy use were highly dependent on process conditions used in the ethanol production plant. Potential for significant ethanol cost reductions exist in increasing pentose fermentation efficiency and reducing biomass and enzyme costs. The results demonstrated the importance of addressing the tradeoffs in capital costs, pretreatment and downstream processing technologies.

Impact of pretreatment and downstream processing technologies on economics and energy in cellulosic ethanol production

PubMed Central

2011-01-01

Background While advantages of biofuel have been widely reported, studies also highlight the challenges in large scale production of biofuel. Cost of ethanol and process energy use in cellulosic ethanol plants are dependent on technologies used for conversion of feedstock. Process modeling can aid in identifying techno-economic bottlenecks in a production process. A comprehensive techno-economic analysis was performed for conversion of cellulosic feedstock to ethanol using some of the common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. Detailed process models incorporating feedstock handling, pretreatment, simultaneous saccharification and co-fermentation, ethanol recovery and downstream processing were developed using SuperPro Designer. Tall Fescue (Festuca arundinacea Schreb) was used as a model feedstock. Results Projected ethanol yields were 252.62, 255.80, 255.27 and 230.23 L/dry metric ton biomass for conversion process using dilute acid, dilute alkali, hot water and steam explosion pretreatment technologies respectively. Price of feedstock and cellulose enzymes were assumed as $50/metric ton and 0.517/kg broth (10% protein in broth, 600 FPU/g protein) respectively. Capital cost of ethanol plants processing 250,000 metric tons of feedstock/year was $1.92, $1.73, $1.72 and $1.70/L ethanol for process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Ethanol production cost of $0.83, $0.88, $0.81 and $0.85/L ethanol was estimated for production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Water use in the production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment was estimated 5.96, 6.07, 5.84 and 4.36 kg/L ethanol respectively. Conclusions Ethanol price and energy use were highly dependent on process conditions used in the ethanol production plant. Potential for significant ethanol cost reductions exist in increasing pentose fermentation efficiency and reducing biomass and enzyme costs. The results demonstrated the importance of addressing the tradeoffs in capital costs, pretreatment and downstream processing technologies. PMID:21892958