Advanced materials for automobiles

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

Narula, C.K.; Allison, J.E.; Bauer, D.R.

Quite early on, manufacturers realized that lighter automobiles (with gas and diesel engines) would be more fuel efficient and produce fewer tailpipe emissions. They also realized that burning diesel fuel at elevated temperatures (1,315 C) would result in similar improvements. However, materials limitations prevent the operation of diesel vehicles at high temperatures. The fuel efficiency of gasoline-powered vehicles is currently improved by reducing the weight of the automobile and treated the emissions with a three-way catalyst. Additional improvements can be achieved with the use of advanced materials that reduce the weight of vehicles without compromising safety. The use of ceramics,more » fiber-reinforced plastics, and metal-matrix composites are discussed. The paper also discusses automotive catalysts and their components, electrically heated catalyst devices, a lean-burn NOx catalyst, and the future for materials chemistry.« less

A New Energy-Saving Catalytic System: Carbon Dioxide Activation by a Metal/Carbon Catalyst.

PubMed

Yun, Danim; Park, Dae Sung; Lee, Kyung Rok; Yun, Yang Sik; Kim, Tae Yong; Park, Hongseok; Lee, Hyunjoo; Yi, Jongheop

2017-09-22

The conversion of CO 2 into useful chemicals is an attractive method to reduce greenhouse gas emissions and to produce sustainable chemicals. However, the thermodynamic stability of CO 2 means that a lot of energy is required for its conversion into chemicals. Here, we suggest a new catalytic system with an alternative heating system that allows minimal energy consumption during CO 2 conversion. In this system, electrical energy is transferred as heat energy to the carbon-supported metal catalyst. Fast ramping rates allow high operating temperatures (T app =250 °C) to be reached within 5 min, which leads to an 80-fold decrease of energy consumption in methane reforming using CO 2 (DRM). In addition, the consumed energy normalized by time during the DRM reaction in this current-assisted catalysis is sixfold lower (11.0 kJ min -1 ) than that in conventional heating systems (68.4 kJ min -1 ). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Commercial-scale demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) process. Technical progress report number 6, October 1--December 31, 1995

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

NONE

1996-12-31

The project involves the construction of an 80,000 gallons per day (260 TPD) methanol unit utilizing coal-derived synthesis gas from Eastman`s integrated coal gasification facility. The new equipment consists of synthesis gas feed preparation and compression facilities, the liquid phase reactor and auxiliaries, product distillation facilities, and utilities. The technology to be demonstrated is the product of a cooperative development effort by Air Products and DOE in a program that started in 1981. Developed to enhance electric power generation using integrated gasification combined cycle (IGCC) technology, the LPMEOH{trademark} process is ideally suited for directly processing gases produced by modern-day coalmore » gasifiers. This liquid phase process suspends fine catalyst particles in an inert liquid, forming a slurry. The slurry dissipates the heat of the chemical reaction away from the catalyst surface protecting the catalyst and allowing the methanol synthesis reaction to proceed at higher rates. At the Eastman complex, the technology will be integrated with existing coal-gasifiers. A carefully developed test plan will allow operations at Eastman to simulate electricity demand load-following in coal-based IGCC facilities. The operations will also demonstrate the enhanced stability and heat dissipation of the conversion process, its reliable on/off operation, and its ability to produce methanol as a clean liquid fuel without additional upgrading. An off-site product testing program will be conducted to demonstrate the suitability of the methanol product as a transportation fuel and as a fuel for stationary applications for small modular electric power generators for distributed power.« less

Exhaust gas ignition

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

NONE

1996-04-01

This article describes a system developed for rapid light-off of underbody catalysts that has shown potential to meet Euro Stage III emissions targets and to be more cost-effective than some alternatives. Future emissions legislation will require SI engine aftertreatment systems to approach full operating efficiency within the first few seconds after starting to reduce the high total-emissions fraction currently contributed by the cold phase of driving. A reduction of cold-start emissions during Phase 1 (Euro) or Bag 1 (FTP), which in many cases can be as much as 80% of the total for the cycle, has been achieved by electricalmore » heating of the catalytic converter. But electrically heated catalyst (EHC) systems require high currents (100--200 A) to heat the metallic substrate to light-off temperatures over the first 15--20 seconds. Other viable approaches to reducing cold-start emissions include use of a fuel-powered burner upstream of the catalyst. However, as with EHC, the complexity of parts and the introduction of raw fuel into the exhaust system make this device unsatisfactory. Still another approach, an exhaust gas ignition (EGI) system, was first demonstrated in 1991. The operation of a system developed by engineers at Ford Motor Co., Ltd., Cambustion Ltd., and Tickford Ltd. is described here.« less

Spongy Raney nickel hydrogen electrodes for alkaline fuel cells

NASA Astrophysics Data System (ADS)

Tomida, Tahei; Nakabayashi, Ichiro

1989-11-01

Spongy Raney nickel catalysts for use as hydrogen electrodes of fuel cells were prepared by a new method. In this method molten aluminum was sprayed on both sides of a spongy plate of nickel as substrate with an acetylene-oxygen flame gun. Then, the spongy nickel electrodes were activated by alloying at a given temperature of from 550 to 750 C, and leaching the aluminum from the alloy in alkaline solution. This type of catalyst showed good thermal and electrical conductivity and also mechanical strength by itself. Its polarization resistance was very low, and the characteristics of the electrodes improved with increase in the temperature of heat-treatment for alloying. The finding that activity depended on the alloying temperature was consistent with observations by scanning electron microscope on the surface textures of catalysts alloyed at different temperatures.

Autothermal and partial oxidation reformer-based fuel processor, method for improving catalyst function in autothermal and partial oxidation reformer-based processors

DOEpatents

Ahmed, Shabbir; Papadias, Dionissios D.; Lee, Sheldon H. D.; Ahluwalia, Rajesh K.

2013-01-08

The invention provides a fuel processor comprising a linear flow structure having an upstream portion and a downstream portion; a first catalyst supported at the upstream portion; and a second catalyst supported at the downstream portion, wherein the first catalyst is in fluid communication with the second catalyst. Also provided is a method for reforming fuel, the method comprising contacting the fuel to an oxidation catalyst so as to partially oxidize the fuel and generate heat; warming incoming fuel with the heat while simultaneously warming a reforming catalyst with the heat; and reacting the partially oxidized fuel with steam using the reforming catalyst.

Method for improving catalyst function in auto-thermal and partial oxidation reformer-based processors

DOEpatents

Ahmed, Shabbir; Papadias, Dionissios D.; Lee, Sheldon H.D.; Ahluwalia, Rajesh K.

2014-08-26

The invention provides a method for reforming fuel, the method comprising contacting the fuel to an oxidation catalyst so as to partially oxidize the fuel and generate heat; warming incoming fuel with the heat while simultaneously warming a reforming catalyst with the heat; and reacting the partially oxidized fuel with steam using the reforming catalyst.

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

Arendt, Paul N.; DePaula, Ramond F.; Zhu, Yuntian T.

An array of carbon nanotubes is prepared by exposing a catalyst structure to a carbon nanotube precursor. Embodiment catalyst structures include one or more trenches, channels, or a combination of trenches and channels. A system for preparing the array includes a heated surface for heating the catalyst structure and a cooling portion that cools gas above the catalyst structure. The system heats the catalyst structure so that the interaction between the precursor and the catalyst structure results in the formation of an array of carbon nanotubes on the catalyst structure, and cools the gas near the catalyst structure and alsomore » cools any carbon nanotubes that form on the catalyst structure to prevent or at least minimize the formation of amorphous carbon. Arrays thus formed may be used for spinning fibers of carbon nanotubes.« less

Effect of Electric Discharge on Properties of Nano-Particulate Catalyst for Plasma-Catalysis.

PubMed

Lee, Chung Jun; Kim, Jip; Kim, Taegyu

2016-02-01

Heterogeneous catalytic processes have been used to produce hydrogen from hydrocarbons. However, high reforming temperature caused serious catalyst deteriorations and low energy efficiency. Recently, a plasma-catalyst hybrid process was used to reduce the reforming temperature and to improve the stability and durability of reforming catalysts. Effect of electric discharges on properties of nanoparticulate catalysts for plasma-catalysis was investigated in the present study. Catalyst-bed porosity was varied by packing catalyst beads with the different size in a reactor. Discharge power and onset voltage of the plasma were measured as the catalyst-bed porosity was varied. The effect of discharge voltage, frequency and voltage waveforms such as the sine, pulse and square was investigated. We found that the optimal porosity of the catalyst-bed exists to maximize the electric discharge. At a low porosity, the electric discharge was unstable to be sustained because the space between catalysts got narrow nearly close to the sheath region. On the other hand, at a high porosity, the electric discharge became weak because the plasma was not sufficient to interact with the surface of catalysts. The discharge power increased as the discharge voltage and frequency increased. The square waveform was more efficient than the sine and pulse one. At a high porosity, however, the effect of the voltage waveform was not considerable because the space between catalysts was too large for plasma to interact with the surface of catalysts.

Conductive polymer layers to limit transfer of fuel reactants to catalysts of fuel cells to reduce reactant crossover

DOEpatents

Stanis, Ronald J.; Lambert, Timothy N.

2016-12-06

An apparatus of an aspect includes a fuel cell catalyst layer. The fuel cell catalyst layer is operable to catalyze a reaction involving a fuel reactant. A fuel cell gas diffusion layer is coupled with the fuel cell catalyst layer. The fuel cell gas diffusion layer includes a porous electrically conductive material. The porous electrically conductive material is operable to allow the fuel reactant to transfer through the fuel cell gas diffusion layer to reach the fuel cell catalyst layer. The porous electrically conductive material is also operable to conduct electrons associated with the reaction through the fuel cell gas diffusion layer. An electrically conductive polymer material is coupled with the fuel cell gas diffusion layer. The electrically conductive polymer material is operable to limit transfer of the fuel reactant to the fuel cell catalyst layer.

Steam reforming of fuel to hydrogen in fuel cells

DOEpatents

Fraioli, Anthony V.; Young, John E.

1984-01-01

A fuel cell capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

Preparation of graphene-ZrO2 nanocomposites by heat treatment and photocatalytic degradation of organic dyes.

PubMed

Cho, Bum Hwi; Ko, Weon Bae

2013-11-01

ZrO2 nanoparticles were synthesized by combining a solution containing zinconyl chloride in distilled water with a NH4OH solution under microwave irradiation. Graphene and ZrO2 nanocomposites were synthesized in an electric furnace at 700 degrees C for 2 hours. The heated graphene-ZrO2 nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. In addition, UV-vis spectrophotometry was used to evaluate the heated graphene-ZrO2 nanocomposites as a catalyst in the photocatalytic degradation of organic dyes. The photocatalytic effect of the heated graphene-ZrO2 nanocomposites was compared with that of unheated graphene nanoparticles, heated graphene nanoparticles, and unheated graphene-ZrO2 nanocomposites in organic dyes (methylene blue, methyl orange, and rhodamine B) under ultraviolet light at 254 nm.

Towards Stable CuZnAl Slurry Catalysts for the Synthesis of Ethanol from Syngas

NASA Astrophysics Data System (ADS)

Dong, Weibing; Gao, Zhihua; Zhang, Qian; Huang, Wei

2018-07-01

A stable CuZnAl slurry catalyst for the synthesis of ethanol from syngas has been developed by adjusting the heat treatment conditions of the complete liquid-phase method. The activity evaluation results showed that the CuZnAl catalyst, when heat-treated under a high pressure and temperature, was a stable catalyst for the synthesis of ethanol. The selectivity of ethanol using the CuZnAl slurry catalyst, which was heat-treated at 553 K under 4.0 MPa, increased continuously with time and was stable at approximately 26.00% after 144 h. The characterization results indicated that the CuZnAl slurry catalyst heat-treated under high pressure conditions could facilitate the formation of a more perfect structure with a larger specific surface area. The prepared catalyst contained a balance of strong and weak acid sites, an appropriate form of Cu2O and a high Cu/Zn atomic ratio at the catalyst surface, providing its stability in ethanol synthesis from syngas.

Steam reforming of fuel to hydrogen in fuel cell

DOEpatents

Young, J.E.; Fraioli, A.V.

1983-07-13

A fuel cell is described capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

Electrospun Nb-doped TiO2 nanofiber support for Pt nanoparticles with high electrocatalytic activity and durability

NASA Astrophysics Data System (ADS)

Kim, Minjoong; Kwon, Chorong; Eom, Kwangsup; Kim, Jihyun; Cho, Eunae

2017-03-01

This study explores a facile method to prepare an efficient and durable support for Pt catalyst of polymer electrolyte membrane fuel cell (PEMFC). As a candidate, Nb-doped TiO2 (Nb-TiO2) nanofibers are simply fabricated using an electrospinning technique, followed by a heat treatment. Doping Nb into the TiO2 nanofibers leads to a drastic increase in electrical conductivity with doping level of up to 25 at. % (Nb0.25Ti0.75O2). Pt nanoparticles are synthesized on the prepared 25 at. % Nb-doped TiO2-nanofibers (Pt/Nb-TiO2) as well as on a commercial powdered carbon black (Pt/C). The Pt/Nb-TiO2 nanofiber catalyst exhibits similar oxygen reaction reduction (ORR) activity to that of the Pt/C catalyst. However, during an accelerated stress test (AST), the Pt/Nb-TiO2 nanofiber catalyst retained more than 60% of the initial ORR activity while the Pt/C catalyst lost 65% of the initial activity. The excellent durability of the Pt/Nb-TiO2 nanofiber catalyst can be attributed to high corrosion resistance of TiO2 and strong interaction between Pt and TiO2.

Electrospun Nb-doped TiO2 nanofiber support for Pt nanoparticles with high electrocatalytic activity and durability.

PubMed

Kim, MinJoong; Kwon, ChoRong; Eom, KwangSup; Kim, JiHyun; Cho, EunAe

2017-03-14

This study explores a facile method to prepare an efficient and durable support for Pt catalyst of polymer electrolyte membrane fuel cell (PEMFC). As a candidate, Nb-doped TiO 2 (Nb-TiO 2 ) nanofibers are simply fabricated using an electrospinning technique, followed by a heat treatment. Doping Nb into the TiO 2 nanofibers leads to a drastic increase in electrical conductivity with doping level of up to 25 at. % (Nb 0.25 Ti 0.75 O 2 ). Pt nanoparticles are synthesized on the prepared 25 at. % Nb-doped TiO 2 -nanofibers (Pt/Nb-TiO 2 ) as well as on a commercial powdered carbon black (Pt/C). The Pt/Nb-TiO 2 nanofiber catalyst exhibits similar oxygen reaction reduction (ORR) activity to that of the Pt/C catalyst. However, during an accelerated stress test (AST), the Pt/Nb-TiO 2 nanofiber catalyst retained more than 60% of the initial ORR activity while the Pt/C catalyst lost 65% of the initial activity. The excellent durability of the Pt/Nb-TiO 2 nanofiber catalyst can be attributed to high corrosion resistance of TiO 2 and strong interaction between Pt and TiO 2 .

Electrospun Nb-doped TiO2 nanofiber support for Pt nanoparticles with high electrocatalytic activity and durability

PubMed Central

Kim, MinJoong; Kwon, ChoRong; Eom, KwangSup; Kim, JiHyun; Cho, EunAe

2017-01-01

This study explores a facile method to prepare an efficient and durable support for Pt catalyst of polymer electrolyte membrane fuel cell (PEMFC). As a candidate, Nb-doped TiO2 (Nb-TiO2) nanofibers are simply fabricated using an electrospinning technique, followed by a heat treatment. Doping Nb into the TiO2 nanofibers leads to a drastic increase in electrical conductivity with doping level of up to 25 at. % (Nb0.25Ti0.75O2). Pt nanoparticles are synthesized on the prepared 25 at. % Nb-doped TiO2-nanofibers (Pt/Nb-TiO2) as well as on a commercial powdered carbon black (Pt/C). The Pt/Nb-TiO2 nanofiber catalyst exhibits similar oxygen reaction reduction (ORR) activity to that of the Pt/C catalyst. However, during an accelerated stress test (AST), the Pt/Nb-TiO2 nanofiber catalyst retained more than 60% of the initial ORR activity while the Pt/C catalyst lost 65% of the initial activity. The excellent durability of the Pt/Nb-TiO2 nanofiber catalyst can be attributed to high corrosion resistance of TiO2 and strong interaction between Pt and TiO2. PMID:28290503

Green Synthesis of Three-Dimensional Hybrid N-Doped ORR Electro-Catalysts Derived from Apricot Sap

PubMed Central

Karunagaran, Ramesh; Coghlan, Campbell; Gulati, Karan; Tung, Tran Thanh; Doonan, Christian

2018-01-01

Rapid depletion of fossil fuel and increased energy demand has initiated a need for an alternative energy source to cater for the growing energy demand. Fuel cells are an enabling technology for the conversion of sustainable energy carriers (e.g., renewable hydrogen or bio-gas) into electrical power and heat. However, the hazardous raw materials and complicated experimental procedures used to produce electro-catalysts for the oxygen reduction reaction (ORR) in fuel cells has been a concern for the effective implementation of these catalysts. Therefore, environmentally friendly and low-cost oxygen reduction electro-catalysts synthesised from natural products are considered as an attractive alternative to currently used synthetic materials involving hazardous chemicals and waste. Herein, we describe a unique integrated oxygen reduction three-dimensional composite catalyst containing both nitrogen-doped carbon fibers (N-CF) and carbon microspheres (N-CMS) synthesised from apricot sap from an apricot tree. The synthesis was carried out via three-step process, including apricot sap resin preparation, hydrothermal treatment, and pyrolysis with a nitrogen precursor. The nitrogen-doped electro-catalysts synthesised were characterised by SEM, TEM, XRD, Raman, and BET techniques followed by electro-chemical testing for ORR catalysis activity. The obtained catalyst material shows high catalytic activity for ORR in the basic medium by facilitating the reaction via a four-electron transfer mechanism. PMID:29382103

Green Synthesis of Three-Dimensional Hybrid N-Doped ORR Electro-Catalysts Derived from Apricot Sap.

PubMed

Karunagaran, Ramesh; Coghlan, Campbell; Shearer, Cameron; Tran, Diana; Gulati, Karan; Tung, Tran Thanh; Doonan, Christian; Losic, Dusan

2018-01-28

Rapid depletion of fossil fuel and increased energy demand has initiated a need for an alternative energy source to cater for the growing energy demand. Fuel cells are an enabling technology for the conversion of sustainable energy carriers (e.g., renewable hydrogen or bio-gas) into electrical power and heat. However, the hazardous raw materials and complicated experimental procedures used to produce electro-catalysts for the oxygen reduction reaction (ORR) in fuel cells has been a concern for the effective implementation of these catalysts. Therefore, environmentally friendly and low-cost oxygen reduction electro-catalysts synthesised from natural products are considered as an attractive alternative to currently used synthetic materials involving hazardous chemicals and waste. Herein, we describe a unique integrated oxygen reduction three-dimensional composite catalyst containing both nitrogen-doped carbon fibers (N-CF) and carbon microspheres (N-CMS) synthesised from apricot sap from an apricot tree. The synthesis was carried out via three-step process, including apricot sap resin preparation, hydrothermal treatment, and pyrolysis with a nitrogen precursor. The nitrogen-doped electro-catalysts synthesised were characterised by SEM, TEM, XRD, Raman, and BET techniques followed by electro-chemical testing for ORR catalysis activity. The obtained catalyst material shows high catalytic activity for ORR in the basic medium by facilitating the reaction via a four-electron transfer mechanism.

Green heterogeneous Pd(II) catalyst produced from chitosan-cellulose micro beads for green synthesis of biaryls.

PubMed

Baran, Talat; Sargin, Idris; Kaya, Murat; Menteş, Ayfer

2016-11-05

In green catalyst systems, both the catalyst and the technique should be environmentally safe. In this study we designed a green palladium(II) catalyst for microwave-assisted Suzuki CC coupling reactions. The catalyst support was produced from biopolymers; chitosan and cellulose. The catalytic activity of the catalyst was tested on 16 substrates in solvent-free media and compared with those of commercial palladium salts. Reusability tests were done. The catalyst was also used in conventional reflux-heating system to demonstrate the efficiency of microwave heating method. We recorded high activity, selectivity and excellent TONs (6600) and TOFs (82500) just using a small catalyst loading (1.5×10(-3)mol%) in short reaction time (5min). The catalyst exhibited a long lifetime (9 runs). The findings indicated that both green chitosan/cellulose-Pd(II) catalyst and the microwave heating are suitable for synthesis of biaryl compounds by using Suzuki CC coupling reactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of Graphitic Content on Carbon Supported Catalyst Performance

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

Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen

2011-07-01

The effect of graphitic content on carbon supported platinum catalysts was investigated in order to investigate its influence on catalyst performance. Four catalysts of varying surface areas and graphitic content were analyzed using XPS, HREELS, and tested using RDE experiments. The catalysts were also heat treated at 150oC and 100%RH as means to uniformly age them. The heat treated samples were analyzed using the same methods to determine what changes had occurred due to this aging process. When compared to the BOL catalysts, heat treated catalysts displayed increased graphitic carbon and platinum metalic content, however they also showed depressed catalyticmore » activity. The primary cause is still under investigation, though it is believed to be related to loss of amorphous carbon content.« less

Effects of fuel processing methods on industrial scale biogas-fuelled solid oxide fuel cell system for operating in wastewater treatment plants

NASA Astrophysics Data System (ADS)

Farhad, Siamak; Yoo, Yeong; Hamdullahpur, Feridun

The performance of three solid oxide fuel cell (SOFC) systems, fuelled by biogas produced through anaerobic digestion (AD) process, for heat and electricity generation in wastewater treatment plants (WWTPs) is studied. Each system has a different fuel processing method to prevent carbon deposition over the anode catalyst under biogas fuelling. Anode gas recirculation (AGR), steam reforming (SR), and partial oxidation (POX) are the methods employed in systems I-III, respectively. A planar SOFC stack used in these systems is based on the anode-supported cells with Ni-YSZ anode, YSZ electrolyte and YSZ-LSM cathode, operated at 800 °C. A computer code has been developed for the simulation of the planar SOFC in cell, stack and system levels and applied for the performance prediction of the SOFC systems. The key operational parameters affecting the performance of the SOFC systems are identified. The effect of these parameters on the electrical and CHP efficiencies, the generated electricity and heat, the total exergy destruction, and the number of cells in SOFC stack of the systems are studied. The results show that among the SOFC systems investigated in this study, the AGR and SR fuel processor-based systems with electrical efficiency of 45.1% and 43%, respectively, are suitable to be applied in WWTPs. If the entire biogas produced in a WWTP is used in the AGR or SR fuel processor-based SOFC system, the electricity and heat required to operate the WWTP can be completely self-supplied and the extra electricity generated can be sold to the electrical grid.

Local Electric Field Effects on Rhodium-Porphyrin and NHC-Gold Catalysts

DTIC Science & Technology

2015-01-05

AFRL-OSR-VA-TR-2015-0023 (NII) - Local Electric Field Effects on Rhodium -Porphyrin and NHC-Gold Catalysts MATTHEW KANAN LELAND STANFORD JUNIOR UNIV...Effects on Rhodium -Porphyrin and NHC-Gold Catalysts Principal Investigator: Matthew W. Kanan Project Publications: 1. “An Electric Field–Induced Change...Stanford University Grant/Contract Title The full title of the funded effort. (NII)-Local Electric Field Effects on Rhodium -Porphyrin and NHC-Gold

Liquid-Phase Electrical Discharges: Fundamental Mechanisms and Applications

NASA Astrophysics Data System (ADS)

Franclemont, Joshua

The increased demand in alternative energy in recent decades has generated significant interest in cleaner fuel sources including hydrogen and syngas (hydrogen and carbon monoxide). Hydrogen and syngas are both primarily produced through the steam reforming of hydrocarbons, specifically natural gas. Although other processes are known, the cheapest source of these fuels is currently through the heating of natural gas in the presence of steam and a catalyst. However, due to the emissions associated with the steam reforming of natural gas and the lack of low cost, efficient, and reliable onboard hydrogen storage technologies for fuel cell powered vehicles, attention has been focused on plasma-assisted reforming of hydrocarbons. Plasma processes can be implemented onboard and are able to directly reform liquid hydrocarbons and alcohols without external heating or catalysts. In addition to hydrogen and syngas, the plasma-assisted reforming of hydrocarbons and alcohols offers other desirable products such as C2 gases (ethane, ethylene, and acetylene), methanol and ethanol. The primary goal of this study is to investigate the fundamental chemical reactions occurring during plasma-assisted reforming of liquid hydrocarbons and alcohols using streamer-like pulsed electrical discharges. Due to the relatively unexplored field of chemical reactions in liquid plasmas, the focus of this study is on elucidating chemical pathways responsible for the formation of hydrogen, syngas, and other products during the direct reforming of liquid methanol, glycerol, and pentane as model species.

Heterogeneous Electrocatalyst of Palladium-Cobalt-Phosphorus on Carbon Support for Oxygen Reduction Reaction in High Temperature Proton Exchange Membrane Fuel Cells.

PubMed

You, Dae Jong; Pak, Chanho; Jin, Seon-Ah; Lee, Kang Hee; Kwon, Kyungjung; Choi, Kyoung Hwan; Heo, Pil Won; Jang, Hongchul; Kim, Jun Young; Kim, Ji Man

2016-05-01

Palladium-cobalt-phosphorus (PdCoP) catalysts supported on carbon (Ketjen Black) were investigated as a cathode catalyst for oxygen reduction reaction (ORR) in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The PdCoP catalyst was synthesized via a modified polyol process in teflon-sealed reactor by microwave-heating. From X-ray diffraction and transmission electron microscopic analysis, the PdCoP catalyst exhibits a face-centered cubic structure, similar to palladium (Pd), which is attributed to form a good solid solution of Co atoms and P atoms in the Pd lattice. The PdCoP nanoparticles with average diameter of 2.3 nm were uniformly distributed on the carbon support. The electrochemical surface area (ECSA) and ORR activity of PdP, PdCo and PdCoP catalysts were measured using a rotating disk electrode technique with cyclic voltammetry and the linear sweep method. The PdCoP catalysts showed the highest performances for ECSA and ORR, which might be attributed both to formation of small nanoparticle by phosphorus atom and to change in lattice constant of Pd by cobalt atom. Furthermore, The HT-PEMFCs single cell performance employing PdCoP catalyst exhibited an enhanced cell performance compared to a single cell using the PdP and PdCo catalysts. This result indicates the importance of electric and geometric control of Pd alloy nanoparticles that can improve the catalytic activity. This synergistic combination of Co and P with Pd could provide the direction of development of non-Pt catalyst for fuel cell system.

Catalysts for cleaner combustion of coal, wood and briquettes sulfur dioxide reduction options for low emission sources

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

Smith, P.V.

1995-12-31

Coal fired, low emission sources are a major factor in the air quality problems facing eastern European cities. These sources include: stoker-fired boilers which feed district heating systems and also meet local industrial steam demand, hand-fired boilers which provide heat for one building or a small group of buildings, and masonary tile stoves which heat individual rooms. Global Environmental Systems is marketing through Global Environmental Systems of Polane, Inc. catalysts to improve the combustion of coal, wood or fuel oils in these combustion systems. PCCL-II Combustion Catalysts promotes more complete combustion, reduces or eliminates slag formations, soot, corrosion and somemore » air pollution emissions and is especially effective on high sulfur-high vanadium residual oils. Glo-Klen is a semi-dry powder continuous acting catalyst that is injected directly into the furnace of boilers by operating personnel. It is a multi-purpose catalyst that is a furnace combustion catalyst that saves fuel by increasing combustion efficiency, a cleaner of heat transfer surfaces that saves additional fuel by increasing the absorption of heat, a corrosion-inhibiting catalyst that reduces costly corrosion damage and an air pollution reducing catalyst that reduces air pollution type stack emissions. The reduction of sulfur dioxides from coal or oil-fired boilers of the hand fired stoker design and larger, can be controlled by the induction of the Glo-Klen combustion catalyst and either hydrated lime or pulverized limestone.« less

Reactivation of a tin oxide-containing catalyst

NASA Technical Reports Server (NTRS)

Brown, Kenneth G. (Inventor); Hess, Robert V. (Inventor); Paulin, Patricia A. (Inventor); Miller, Irvin M. (Inventor); Schryer, David R. (Inventor); Upchurch, Billy T. (Inventor); Sidney, Barry D. (Inventor); Wood, George M. (Inventor)

1989-01-01

A method for the reactivation of a tin oxide-containing catalyst of a CO.sub.2 laser is provided. First, the catalyst is pretreated by a standard procedure. When the catalyst experiences diminished activity during usage, the heated zone surrounding the catalyst is raised to a temperature which is the operating temperature of the laser and 400.degree. C. for approximately one hour. The catalyst is exposed to the same laser gas mixture during this period. The temperature of the heated zone is then lowered to the operating temperature of the CO.sub.2 laser.

Synthesis of mesoporous SAPO-34 molecular sieves and their applications in dehydration of butanols and ethanol.

PubMed

Jun, Jong Won; Jeon, Jaewoo; Kim, Chul-Ung; Jeong, Kwang-Eun; Jeong, Soon-Yong; Jhung, Sung Hwa

2013-04-01

Microporous SAPO-34 molecular sieves were hydrothermally synthesized with microwave irradiation in the presence of tetraethylammonium hydroxide (TEAOH) as a template. SAPO-34 molecular sieves with mesoporosity were also prepared in the presence of carbon black as a hard template. By increasing the content of the carbon black template in the synthesis, the mesopore volume increased. Dehydration of alcohols (butanols and ethanol) was carried out with the synthesized SAPO-34 molecular sieves, and the lifetime of the catalysts for the dehydration reaction increased as the mesoporosity increased. Moreover, the performance of the microporous catalyst synthesized with microwave was better than that of the catalyst obtained with conventional electric heating. The relative performance of the catalytic dehydration may be explained by the mesoporosity and the crystal size. Therefore, it may be concluded that small-sized SAPO-34 molecular sieves with high mesoporosity can be produced efficiently with microwave irradiation in the presence of carbon black template, and the molecular sieves are effective in the stable dehydration of alcohols.

Activity of Co-N multi walled carbon nanotubes electrocatalysts for oxygen reduction reaction in acid conditions

NASA Astrophysics Data System (ADS)

Osmieri, Luigi; Monteverde Videla, Alessandro H. A.; Specchia, Stefania

2015-03-01

Two catalysts are synthesized by wet impregnation of multi walled carbon nanotubes (MWCNT) with a complex formed between Co(II) ions and the nitrogen-containing molecule 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ), followed by one or two identical heat treatments in N2 atmosphere at 800 °C for 3 h. Catalysts are fully characterized by FESEM, EDX, BET, XRD, FTIR, TGA, XPS analyses, and electrochemical techniques. The electrocatalytic activity towards oxygen reduction reaction (ORR) of the catalysts in acid conditions is assessed by means of a rotating disk electrode (RDE) apparatus and a specific type of cell equipped with a gas diffusion working electrode (GDE). In both testing approaches, the catalyst heat-treated twice (Co-N/MWCNT-2) exhibits higher electroactivity than the catalyst heat-treated once (Co-N/MWCNT-1). Chronoamperometries both in RDE and GDE cell are also performed, showing less electroactivity decay and better current performance for the catalyst heat-treated twice.

Catalysts as sensors--a promising novel approach in automotive exhaust gas aftertreatment.

PubMed

Moos, Ralf

2010-01-01

Sensors that detect directly and in situ the status of automotive exhaust gas catalysts by monitoring the electrical properties of the catalyst coating itself are overviewed. Examples included in this review are the in-situ determination of the electrical impedance of three-way catalysts based on ceria-zirconia solutions and of lean NO(x) traps of earth-alkaline based coatings, as well as approaches to determine the ammonia loading in Fe-SCR-zeolites with electrical ac measurements. Even more sophisticated approaches based on interactions with electromagnetic waves are also reviewed. For that purpose, metallic stick-like antennas are inserted into the exhaust pipe. The catalyst properties are measured in a contactless manner, directly indicating the catalyst status. The radio frequency probes gauge the oxygen loading degree of three-way catalysts, the NO(x)-loading of lean NO(x) traps, and the soot loading of Diesel particulate filters.

Catalysts as Sensors—A Promising Novel Approach in Automotive Exhaust Gas Aftertreatment

PubMed Central

Moos, Ralf

2010-01-01

Sensors that detect directly and in situ the status of automotive exhaust gas catalysts by monitoring the electrical properties of the catalyst coating itself are overviewed. Examples included in this review are the in-situ determination of the electrical impedance of three-way catalysts based on ceria-zirconia solutions and of lean NOx traps of earth-alkaline based coatings, as well as approaches to determine the ammonia loading in Fe-SCR-zeolites with electrical ac measurements. Even more sophisticated approaches based on interactions with electromagnetic waves are also reviewed. For that purpose, metallic stick-like antennas are inserted into the exhaust pipe. The catalyst properties are measured in a contactless manner, directly indicating the catalyst status. The radio frequency probes gauge the oxygen loading degree of three-way catalysts, the NOx-loading of lean NOx traps, and the soot loading of Diesel particulate filters. PMID:22163575

Preparation of C60(O)n-ZnO nanocomposite under electric furnace and photocatalytic degradation of organic dyes.

PubMed

Cho, Bum Hwi; Oh, Youn Jun; Mun, Sang Mi; Ko, Weon Bae

2012-07-01

Zinc oxide (ZnO) nanoparticles were synthesized sonochemically by applying ultrasonic irradiation to a mixed aqueous-alcoholic solution of zinc nitrate with sodium hydroxide at room temperature. The morphology and optical properties of the ZnO nanoparticles were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis spectroscopy. The C60(O)n nanoparticles were synthesized by heating a mixture of C60 and 3-chloroperoxybenzoic acid in a benzene solvent under the reflux system. The heated C60(O)n-ZnO nanocomposite was synthesized in an electric furnace at 700 degrees C for two hours. The heated C60(O)n-ZnO nanocomposite was characterized by XRD, SEM, and TEM, and examined as a catalyst in the photocatalytic degradation of organic dyes by UV-vis spectroscopy. The photocatalytic effect of the heated C60(O)n-ZnO nanocomposite was evaluated by a comparison with that of unheated C60(O)n nanoparticles, heated C60(O)n nanoparticles, and unheated C60(O)n-ZnO in organic dyes, such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) under ultraviolet light at 365 nm.

Method for producing electricity using a platinum-ruthenium-palladium catalyst in a fuel cell

DOEpatents

Gorer, Alexander

2004-01-27

A method for producing electricity using a fuel cell that utilizes a ternary alloy composition as a fuel cell catalyst, the ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

Graphitic biocarbon from metal-catalyzed hydrothermal carbonization of lignin

DOE PAGES

Demir, Muslum; Kahveci, Zafer; Aksoy, Burak; ...

2015-10-09

Lignin is a high-volume byproduct from the pulp and paper industry and is currently burned to generate electricity and process heat. Moreover, the industry has been searching for high value-added uses of lignin to improve the process economics. In addition, battery manufacturers are seeking nonfossil sources of graphitic carbon for environmental sustainability. In our work, lignin (which is a cross-linked polymer of phenols, a component of biomass) is converted into graphitic porous carbon using a two-step conversion. Lignin is first carbonized in water at 300 °C and 1500 psi to produce biochar, which is then graphitized using a metal nitratemore » catalyst at 900–1100 °C in an inert gas at 15 psi. Graphitization effectiveness of three different catalysts—iron, cobalt, and manganese nitrates—is examined. The product is analyzed for morphology, thermal stability, surface properties, and electrical conductivity. Both temperature and catalyst type influenced the degree of graphitization. A good quality graphitic carbon was obtained using catalysis by Mn(NO 3) 2 at 900 °C and Co(NO 3) 2 at 1100 °C.« less

The effect of electrospun nanofibers alignment on the synthesis of one-dimensional silicon carbide nanostructure

NASA Astrophysics Data System (ADS)

Hooshyar, Ali; Kokabi, Mehrdad

2018-01-01

One-dimensional silicon carbide (1D SiC) nanostructure has shown unusual properties such as extremely high strength, good flexibility, fracture toughness, wide band gap ( 3.2eV), large breakdown electric field strength (>2 MV cm-1, 10 times that of silicon), and inverse Hall-Petch effect. Because of these advantages, 1D SiC nanomaterial has gained extensive attention on the wide range of applications in microelectronics, optoelectronics, nanocomposites, and catalyst supports. Many methods have been used for the synthesis of 1D SiC nanostructures such as chemical vapor deposition, carbon nanotube-confined reaction, laser ablation, high-frequency induction heating, and arc discharge. However, these methods have also some shortcomings such as using catalyst, high-cost, low yield, irregular geometry and impurity. In this work, electrospinning was used to prepare aligned PVA/SiO2 composite nanofibers and the effect of fiber alignment on the production efficiency and quality of 1D SiC nanostructure was investigated. For this purpose, aligned electrospun nanofibers, as the desirable precursor, were put in a tube furnace and heated up to 1250°C under a controlled program in an inert atmosphere. Finally, the grown 1D SiC nanostructure product was characterized using SEM, XRD, and FTIR. The results confirmed the successful synthesis of pure crystalline1D β-SiC nanostructure with high yield, more regular, and metal catalyst-free.

Hydrocarbon synthesis catalyst and method of preparation

DOEpatents

Sapienza, R.S.; Sansone, M.J.; Slegeir, W.A.R.

1983-08-02

A catalyst for the synthesis of hydrocarbons from carbon monoxide and hydrogen composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants. The catalyst is preferably used in dilute slurry form, which is desirable from a heat transfer standpoint. 9 figs.

Hydrocarbon synthesis catalyst and method of preparation

DOEpatents

Sapienza, Richard S.; Sansone, Michael J.; Slegeir, William A. R.

1983-08-02

A catalyst for the synthesis of hydrocarbons from carbon monoxide and hydrogen composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants. The catalyst is preferably used in dilute slurry form, which is desirable from a heat transfer standpoint.

Exhaust gas purification system for lean burn engine

DOEpatents

Haines, Leland Milburn

2002-02-19

An exhaust gas purification system for a lean burn engine includes a thermal mass unit and a NO.sub.x conversion catalyst unit downstream of the thermal mass unit. The NO.sub.x conversion catalyst unit includes at least one catalyst section. Each catalyst section includes a catalytic layer for converting NO.sub.x coupled to a heat exchanger. The heat exchanger portion of the catalyst section acts to maintain the catalytic layer substantially at a desired temperature and cools the exhaust gas flowing from the catalytic layer into the next catalytic section in the series. In a further aspect of the invention, the exhaust gas purification system includes a dual length exhaust pipe upstream of the NO.sub.x conversion catalyst unit. The dual length exhaust pipe includes a second heat exchanger which functions to maintain the temperature of the exhaust gas flowing into the thermal mass downstream near a desired average temperature.

Rapid starting methanol reactor system

DOEpatents

Chludzinski, Paul J.; Dantowitz, Philip; McElroy, James F.

1984-01-01

The invention relates to a methanol-to-hydrogen cracking reactor for use with a fuel cell vehicular power plant. The system is particularly designed for rapid start-up of the catalytic methanol cracking reactor after an extended shut-down period, i.e., after the vehicular fuel cell power plant has been inoperative overnight. Rapid system start-up is accomplished by a combination of direct and indirect heating of the cracking catalyst. Initially, liquid methanol is burned with a stoichiometric or slightly lean air mixture in the combustion chamber of the reactor assembly. The hot combustion gas travels down a flue gas chamber in heat exchange relationship with the catalytic cracking chamber transferring heat across the catalyst chamber wall to heat the catalyst indirectly. The combustion gas is then diverted back through the catalyst bed to heat the catalyst pellets directly. When the cracking reactor temperature reaches operating temperature, methanol combustion is stopped and a hot gas valve is switched to route the flue gas overboard, with methanol being fed directly to the catalytic cracking reactor. Thereafter, the burner operates on excess hydrogen from the fuel cells.

Electrocatalytic properties of graphite nanofibers-supported platinum catalysts for direct methanol fuel cells.

PubMed

Park, Soo-Jin; Park, Jeong-Min; Seo, Min-Kang

2009-09-01

Graphite nanofibers (GNFs) treated at various temperatures were used as carbon supports to improve the efficiency of PtRu catalysts. The electrochemical properties of the PtRu/GNFs catalysts were then investigated to evaluate their potential for application in DMFCs. The results indicated that the particle size and dispersibility of PtRu in the catalysts were changed by heat treatment, and the electrochemical activity of the catalysts was improved. Consequently, it was found that heat treatments could have an influence on the surface and structural properties of GNFs, resulting in enhancing an electrocatalytic activity of the catalysts for DMFCs.

One-step synthesis of carbon nanosheets converted from a polycyclic compound and their direct use as transparent electrodes of ITO-free organic solar cells.

PubMed

Son, Su-Young; Noh, Yong-Jin; Bok, Changsuk; Lee, Sungho; Kim, Byoung Gak; Na, Seok-In; Joh, Han-Ik

2014-01-21

Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm(-2) illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics.

Method of fabrication of anchored nanostructure materials

DOEpatents

Seals, Roland D; Menchhofer, Paul A; Howe, Jane Y; Wang, Wei

2013-11-26

Methods for fabricating anchored nanostructure materials are described. The methods include heating a nano-catalyst under a protective atmosphere to a temperature ranging from about 450.degree. C. to about 1500.degree. C. and contacting the heated nano-catalysts with an organic vapor to affix carbon nanostructures to the nano-catalysts and form the anchored nanostructure material.

Shielded regeneration heating element for a particulate filter

DOEpatents

Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

2011-01-04

An exhaust system includes a particulate filter (PF) that is disposed downstream from an engine. The PF filters particulates within an exhaust from the engine. A heating element heats particulate matter in the PF. A catalyst substrate or a flow converter is disposed upstream from said heating element. The catalyst substrate oxidizes the exhaust prior to reception by the heating element. The flow converter converts turbulent exhaust flow to laminar exhaust flow prior to reception by the heating element.

Chelating agent-assisted heat treatment of a carbon-supported iron oxide nanoparticle catalyst for PEMFC.

PubMed

Liu, Shyh-Jiun; Huang, Chia-Hung; Huang, Chun-Kai; Hwang, Weng-Sing

2009-08-28

Iron complexes were supported on commercial carbon black and heat treated to create FeO(x)/C catalysts that showed a larger normalized current density and normalized power density than commercial Pt/C catalysts; the coordination number of the iron complexes used affected the formation of the active site for oxygen reduction in PEMFC.

High aspect ratio catalytic reactor and catalyst inserts therefor

DOEpatents

Lin, Jiefeng; Kelly, Sean M.

2018-04-10

The present invention relates to high efficient tubular catalytic steam reforming reactor configured from about 0.2 inch to about 2 inch inside diameter high temperature metal alloy tube or pipe and loaded with a plurality of rolled catalyst inserts comprising metallic monoliths. The catalyst insert substrate is formed from a single metal foil without a central supporting structure in the form of a spiral monolith. The single metal foil is treated to have 3-dimensional surface features that provide mechanical support and establish open gas channels between each of the rolled layers. This unique geometry accelerates gas mixing and heat transfer and provides a high catalytic active surface area. The small diameter, high aspect ratio tubular catalytic steam reforming reactors loaded with rolled catalyst inserts can be arranged in a multi-pass non-vertical parallel configuration thermally coupled with a heat source to carry out steam reforming of hydrocarbon-containing feeds. The rolled catalyst inserts are self-supported on the reactor wall and enable efficient heat transfer from the reactor wall to the reactor interior, and lower pressure drop than known particulate catalysts. The heat source can be oxygen transport membrane reactors.

Development and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

Kaufman, A.

1982-01-01

The on-site system application analysis is summarized. Preparations were completed for the first test of a full-sized single cell. Emphasis of the methanol fuel processor development program shifted toward the use of commercial shell-and-tube heat exchangers. An improved method for predicting the carbon-monoxide tolerance of anode catalysts is described. Other stack support areas reported include improved ABA bipolar plate bonding technology, improved electrical measurement techniques for specification-testing of stack components, and anodic corrosion behavior of carbon materials.

Vacuum-insulated catalytic converter

DOEpatents

Benson, David K.

2001-01-01

A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

Down-flow moving-bed gasifier with catalyst recycle

DOEpatents

Halow, John S.

1999-01-01

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

Valorization of biogas into liquid hydrocarbons in plasma-catalyst reactor

NASA Astrophysics Data System (ADS)

Nikravech, Mehrdad; Rahmani, Abdelkader; Labidi, Sana; Saintini, Noiric

2016-09-01

Biogas represents an important source of renewable energy issued from biological degradation of biomass. It is planned to produce in Europe the amount of biogas equivalent to 6400 kWh electricity and 4500 kteo (kilo tons equivalent oil) in 2020. Currently the biogas is used in cogeneration engines to produce heat and electricity directly in farms or it is injected in gas networks after purification and odorisation. The aim of this work is to propose a third option that consists of valorization of biogas by transformation into liquid hydrocarbons like acetone, methanol, ethanol, acetic acid etc. These chemicals, among the most important feed materials for chemical industries, retain CO2 molecules participating to reduce the greenhouse gas emissions and have high storage energy capacity. We developed a low temperature atmospheric plasma-catalyst reactor (surface dielectric barrier discharge) to transform biogas into chemicals. The conversion rates of CH4 and CO2 are respectively about 50% and 30% depending on operational conditions. The energetic cost is 25 eV/molecule. The yields of liquid hydrocarbon reaches currently 10% wt. More the 11 liquid chemicals are observed in the liquid fraction. Acknowledgements are due to SPC Programme Energie de demain.

Fabrication of ultralong and electrically uniform single-walled carbon nanotubes on clean substrates.

PubMed

Wang, Xueshen; Li, Qunqing; Xie, Jing; Jin, Zhong; Wang, Jinyong; Li, Yan; Jiang, Kaili; Fan, Shoushan

2009-09-01

We report the controlled growth of ultralong single-wall carbon nanotube (SWNT) arrays using an improved chemical vapor deposition strategy. Using ethanol or methane as the feed gas, monodispersed Fe-Mo as the catalyst, and a superaligned carbon nanotube (CNT) film as the catalyst supporting frame, ultralong CNTs over 18.5 cm long were grown on Si substrates. The growth rate of the CNTs was more than 40 mum/s. No catalyst-related residual material was found on the substrates due to the use of a CNT film as the catalyst supporting frame, facilitating any subsequent fabrication of SWNT-based devices. Electrical transport measurements indicated that the electrical characteristics along a single ultralong SWNT were uniform. We also found that maintaining a spatially homogeneous temperature during the growth process was a critical factor for obtaining constant electrical characteristics along the length of the ultralong SWNTs.

Metallic Nanowire Interconnections for Integrated Circuit Fabrication

NASA Technical Reports Server (NTRS)

Ng, Hou Tee (Inventor); Li, Jun (Inventor); Meyyappan, Meyya (Inventor)

2007-01-01

A method for fabricating an electrical interconnect between two or more electrical components. A conductive layer is provided on a substarte and a thin, patterned catalyst array is deposited on an exposed surface of the conductive layer. A gas or vapor of a metallic precursor of a metal nanowire (MeNW) is provided around the catalyst array, and MeNWs grow between the conductive layer and the catalyst array. The catalyst array and a portion of each of the MeNWs are removed to provide exposed ends of the MeNWs.

Investigation of internal elements impaction on particles circulation in a fluidized bed reactor

NASA Astrophysics Data System (ADS)

Solovev, S. A.; Soloveva, O. V.; Antipin, A. V.; Shamsutdinov, E. V.

2018-01-01

A numerical study of the fluidized bed apparatus in the presence of various internal elements is carried out. A chemical reaction for temperature-dependent processes with heat absorption is considered. The task of incoming heated catalyst granules to the reactor is investigated. The main emphasis is focused on the circulation flows of the catalyst particles, heating of the reactor, and the efficiency of the chemical reaction. The analysis of the impact of various design elements on the efficiency of the reactor is carried out. The influence of feeding heated catalyst device design on the effectiveness of whole reactor heating is educed. The influence of the presence of fine particles on the efficiency of the reaction for different reactor design features is also educed.

Catalytic cartridge SO/sub 3/ decomposer

DOEpatents

Galloway, T.R.

1980-11-18

A catalytic cartridge surrounding a heat pipe driven by a heat source is utilized as a SO/sub 3/ decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO/sub 3/ gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube surrounding the heat pipe. In the axial-flow cartridge, SO/sub 3/ gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and surrounding the heat pipe. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety. A fusion reactor may be used as the heat source.

Development of a reaction cell for in-situ/operando studies of surface of a catalyst under a reaction condition and during catalysis.

PubMed

Nguyen, Luan; Tao, Franklin Feng

2016-06-01

Tracking surface chemistry of a catalyst during catalysis is significant for fundamental understanding of catalytic performance of the catalyst since it allows for establishing an intrinsic correlation between surface chemistry of a catalyst at its working status and its corresponding catalytic performance. Ambient pressure X-ray photoelectron spectroscopy can be used for in-situ studies of surfaces of different materials or devices in a gas. To simulate the gaseous environment of a catalyst in a fixed-bed a flowing gaseous environment of reactants around the catalyst is necessary. Here, we report the development of a new flowing reaction cell for simulating in-situ study of a catalyst surface under a reaction condition in gas of one reactant or during catalysis in a mixture of reactants of a catalytic reaction. The homemade reaction cell is installed in a high vacuum (HV) or ultrahigh vacuum (UHV) environment of a chamber. The flowing gas in the reaction cell is separated from the HV or UHV environment through well sealings at three interfaces between the reaction cell and X-ray window, sample door and aperture of front cone of an energy analyzer. Catalyst in the cell is heated through infrared laser beam introduced through a fiber optics interfaced with the reaction cell through a homemade feedthrough. The highly localized heating on the sample holder and Au-passivated internal surface of the reaction cell effectively minimizes any unwanted reactions potentially catalyzed by the reaction cell. The incorporated laser heating allows a fast heating and a high thermal stability of the sample at a high temperature. With this cell, a catalyst at 800 °C in a flowing gas can be tracked readily.

Solid Catalyst Nanoparticles derived from Oil-Palm Empty Fruit Bunches (OP-EFB) as a Renewable Catalyst for Biodiesel Production

NASA Astrophysics Data System (ADS)

Husin, H.; Asnawi, T. M.; Firdaus, A.; Husaini, H.; Ibrahim, I.; Hasfita, F.

2018-05-01

Solid nanocatalyst derived from oil-palm empty fruit bunches (OP-EFB) fiber was successfully synthesized and its application for biodiesel production was investigated. The OPEFB was treated by burning, milling and heating methods to generate ashes in a nanoparticle size. The nanoparticle palm-bunch ash was characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The effects of the calcination temperature and catalyst amounts for transesterification reactions were investigated. XRD analysis of palm bunch ash exhibited that the highest composition of peaks characteristic were potassium oxide (K2O). SEM analysis showed that the nano palm bunch ash have a particle size ranging of 150-400 nm. The highest conversion of palm-oil to biodiesel reach to 97.90% was observed by using of palm bunch ash nanocatalyst which heated at 600°C, 3 h reaction time and 1% catalyst amount. Reusability of palm bunch ash catalysts was also examined. It was found that of its high active sites, reusable solid catalyst was obtained by just heating of palm bunch ash. It has a capability to reduce not only the amount of catalyst consumption but also reduce the reaction time of transesterification process.

Down-flow moving-bed gasifier with catalyst recycle

DOEpatents

Halow, J.S.

1999-04-20

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction. 1 fig.

Enhancement of plasma generation in catalyst pores with different shapes

NASA Astrophysics Data System (ADS)

Zhang, Yu-Ru; Neyts, Erik C.; Bogaerts, Annemie

2018-05-01

Plasma generation inside catalyst pores is of utmost importance for plasma catalysis, as the existence of plasma species inside the pores affects the active surface area of the catalyst available to the plasma species for catalytic reactions. In this paper, the electric field enhancement, and thus the plasma production inside catalyst pores with different pore shapes is studied with a two-dimensional fluid model. The results indicate that the electric field will be significantly enhanced near tip-like structures. In a conical pore with small opening, the strongest electric field appears at the opening and bottom corners of the pore, giving rise to a prominent ionization rate throughout the pore. For a cylindrical pore, the electric field is only enhanced at the bottom corners of the pore, with lower absolute value, and thus the ionization rate inside the pore is only slightly enhanced. Finally, in a conical pore with large opening, the electric field is characterized by a maximum at the bottom of the pore, yielding a similar behavior for the ionization rate. These results demonstrate that the shape of the pore has a significantly influence on the electric field enhancement, and thus modifies the plasma properties.

Catalytic cartridge SO.sub.3 decomposer

DOEpatents

Galloway, Terry R.

1982-01-01

A catalytic cartridge surrounding a heat pipe driven by a heat source is utilized as a SO.sub.3 decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO.sub.3 gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube surrounding the heat pipe. In the axial-flow cartridge, SO.sub.3 gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and surrounding the heat pipe. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

In situ characterization of catalysts and membranes in a microchannel under high-temperature water gas shift reaction conditions

NASA Astrophysics Data System (ADS)

Cavusoglu, G.; Dallmann, F.; Lichtenberg, H.; Goldbach, A.; Dittmeyer, R.; Grunwaldt, J.-D.

2016-05-01

Microreactor technology with high heat transfer in combination with stable catalysts is a very attractive approach for reactions involving major heat effects such as methane steam reforming and to some extent, also the high temperature water gas shift (WGS) reaction. For this study Rh/ceria catalysts and an ultrathin hydrogen selective membrane were characterized in situ in a microreactor specially designed for x-ray absorption spectroscopic measurements under WGS conditions. The results of these experiments can serve as a basis for further development of the catalysts and membranes.

Guidelines for bottom-up approach of nanocarbon film formation from pentacene using heated tungsten on quartz substrate without metal catalyst

NASA Astrophysics Data System (ADS)

Heya, Akira; Matsuo, Naoto

2018-04-01

The guidelines for a bottom-up approach of nanographene formation from pentacene using heated tungsten were investigated using a novel method called hot mesh deposition (HMD). In this method, a heated W mesh was set between a pentacene source and a quartz substrate. Pentacene molecules were decomposed by the heated W mesh. The generated pentacene-based decomposed precursors were then deposited on the quartz substrate. The pentacene dimer (peripentacene) was obtained from pentacene by HMD using two heated catalysts. As expected from the calculation with the density functional theory in the literature, it was confirmed that the pentacene dimer can be formed by a reaction between pentacene and 6,13-dihydropentacene. This technique can be applied to the formation of novel nanographene on various substrates without metal catalysts.

Catalyst patterning for nanowire devices

NASA Technical Reports Server (NTRS)

Li, Jun (Inventor); Cassell, Alan M. (Inventor); Han, Jie (Inventor)

2004-01-01

Nanowire devices may be provided that are based on carbon nanotubes or single-crystal semiconductor nanowires. The nanowire devices may be formed on a substrate. Catalyst sites may be formed on the substrate. The catalyst sites may be formed using lithography, thin metal layers that form individual catalyst sites when heated, collapsible porous catalyst-filled microscopic spheres, microscopic spheres that serve as masks for catalyst deposition, electrochemical deposition techniques, and catalyst inks. Nanowires may be grown from the catalyst sites.

Additive Manufacturing of Catalyst Substrates for Steam-Methane Reforming

NASA Astrophysics Data System (ADS)

Kramer, Michelle; McKelvie, Millie; Watson, Matthew

2018-01-01

Steam-methane reforming is a highly endothermic reaction, which is carried out at temperatures up to 1100 °C and pressures up to 3000 kPa, typically with a Ni-based catalyst distributed over a substrate of discrete alumina pellets or beads. Standard pellet geometries (spheres, hollow cylinders) limit the degree of mass transfer between gaseous reactants and catalyst. Further, heat is supplied to the exterior of the reactor wall, and heat transfer is limited due to the nature of point contacts between the reactor wall and the substrate pellets. This limits the degree to which the process can be intensified, as well as limiting the diameter of the reactor wall. Additive manufacturing now gives us the capability to design structures with tailored heat and mass transfer properties, not only within the packed bed of the reactor, but also at the interface between the reactor wall and the packed bed. In this work, the use of additive manufacturing to produce monolithic-structured catalyst substrate models, made from acrylonitrile-butadiene-styrene, with enhanced conductive heat transfer is described. By integrating the reactor wall into the catalyst substrate structure, the effective thermal conductivity increased by 34% from 0.122 to 0.164 W/(m K).

Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

PubMed Central

Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

2014-01-01

The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

Processes of conversion of a hot metal particle into aerogel through clusters

NASA Astrophysics Data System (ADS)

Smirnov, B. M.

2015-10-01

Processes are considered for conversion into a fractal structure of a hot metal micron-size particle that is located in a buffer gas or a gas flow and is heated by an external electric or electromagnetic source or by a plasma. The parameter of this heating is the particle temperature, which is the same in the entire particle volume because of its small size and high conductivity. Three processes determine the particle heat balance: particle radiation, evaporation of metal atoms from the particle surface, and heat transport to the surrounding gas due to its thermal conductivity. The particle heat balance is analyzed based on these processes, which are analogous to those for bulk metals with the small particle size, and its high temperature taken into account. Outside the particle, where the gas temperature is lower than on its surface, the formed metal vapor in a buffer gas flow is converted into clusters. Clusters grow as a result of coagulation until they become liquid, and then clusters form fractal aggregates if they are removed form the gas flow. Subsequently, associations of fractal aggregates join into a fractal structure. The rate of this process increases in medium electric fields, and the formed fractal structure has features of aerogels and fractal fibers. As a result of a chain of the above processes, a porous metal film may be manufactured for use as a filter or catalyst for gas flows.

Processes for converting lignocellulosics to reduced acid pyrolysis oil

DOEpatents

Kocal, Joseph Anthony; Brandvold, Timothy A

2015-01-06

Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

Catalytic cartridge SO.sub.3 decomposer

DOEpatents

Galloway, Terry R.

1982-01-01

A catalytic cartridge internally heated is utilized as a SO.sub.3 decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO.sub.3 gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube being internally heated. In the axial-flow cartridge, SO.sub.3 gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and being internally heated. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

Synthesis of renewable diesel through hydrodeoxygenation reaction from nyamplung oil (Calophyllum Inophyllum oil) using NiMo/Z and NiMo/C catalysts with rapid heating and cooling method

NASA Astrophysics Data System (ADS)

Susanto, B. H.; Prakasa, M. B.; Shahab, M. H.

2016-11-01

The synthesis of metal nanocrystal was conducted by modification preparation from simple heating method which heating and cooling process run rapidly. The result of NiMo/Z 575 °C characterizations are 33.73 m2/gram surface area and 31.80 nm crystal size. By used NiMo/C 700 °C catalyst for 30 minutes which had surface area of 263.21 m2/gram, had 31.77 nm crystal size, and good morphology, obtained catalyst with high activity, selectivity, and stability. After catalyst activated, synthesis of renewable diesel performed in hydrogenation reactor at 375 °C, 12 bar, and 800 rpm. The result of conversion was 81.99%, yield was 68.08%, and selectivity was 84.54%.

Crumpled rGO-supported Pt-Ir bifunctional catalyst prepared by spray pyrolysis for unitized regenerative fuel cells

NASA Astrophysics Data System (ADS)

Kim, In Gyeom; Nah, In Wook; Oh, In-Hwan; Park, Sehkyu

2017-10-01

Three-dimensional (3D) crumpled reduced graphene oxide supported Pt-Ir alloys that served as bifunctional oxygen catalysts for use in untized regenerative fuel cells were synthesized by a facile spray pyrolysis method. Pt-Ir catalysts supported on rGO (Pt-Ir/rGOs) were physically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) to observe change in composition by heat treatment, alloying, and morphological transition of the catalysts. Their catalytic activities and stabilities for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) conditions were electrochemically investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), potential cycling and hold tests on the rotating disk electrode (RDE). Pt-Ir/rGO with no post heat-treatment (Pt-Ir/rGO_NP) showed a lower activity for ORR and OER although metal nanoparticles decorated on the support are relatively small. However, Pt-Ir/rGO showed remarkably enhanced activity following heat treatment, depending on temperature. Pt-Ir/rGO heat-treated at 600 °C after spray pyrolysis (Pt-Ir/rGO_P600) exhibited a higher activity and stability than a commercially available Pt/C catalyst kept under the ORR condition, and it also revealed a comparable OER activity and durability versus the commercial unsupported Ir catalyst.

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

Nguyen, Luan; Tao, Franklin, E-mail: franklin.tao.2011@gmail.com; Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, Kansas 66045

Tracking surface chemistry of a catalyst during catalysis is significant for fundamental understanding of catalytic performance of the catalyst since it allows for establishing an intrinsic correlation between surface chemistry of a catalyst at its working status and its corresponding catalytic performance. Ambient pressure X-ray photoelectron spectroscopy can be used for in-situ studies of surfaces of different materials or devices in a gas. To simulate the gaseous environment of a catalyst in a fixed-bed a flowing gaseous environment of reactants around the catalyst is necessary. Here, we report the development of a new flowing reaction cell for simulating in-situ studymore » of a catalyst surface under a reaction condition in gas of one reactant or during catalysis in a mixture of reactants of a catalytic reaction. The homemade reaction cell is installed in a high vacuum (HV) or ultrahigh vacuum (UHV) environment of a chamber. The flowing gas in the reaction cell is separated from the HV or UHV environment through well sealings at three interfaces between the reaction cell and X-ray window, sample door and aperture of front cone of an energy analyzer. Catalyst in the cell is heated through infrared laser beam introduced through a fiber optics interfaced with the reaction cell through a homemade feedthrough. The highly localized heating on the sample holder and Au-passivated internal surface of the reaction cell effectively minimizes any unwanted reactions potentially catalyzed by the reaction cell. The incorporated laser heating allows a fast heating and a high thermal stability of the sample at a high temperature. With this cell, a catalyst at 800 °C in a flowing gas can be tracked readily.« less

Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

NASA Technical Reports Server (NTRS)

1981-01-01

Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

Why does the Conductivity of a Nickel Catalyst Increase during Sulfidation? An Exemplary Study Using an In Operando Sensor Device.

PubMed

Fremerey, Peter; Jess, Andreas; Moos, Ralf

2015-10-23

In order to study the sulfidation of a catalyst fixed bed, an in operando single pellet sensor was designed. A catalyst pellet from the fixed bed was electrically contacted and its electrical response was correlated with the catalyst behavior. For the sulfidation tests, a nickel catalyst was used and was sulfidized with H₂S. This catalyst had a very low conductivity in the reduced state. During sulfidation, the conductivity of the catalyst increased by decades. A reaction from nickel to nickel sulfide occurred. This conductivity increase by decades during sulfidation had not been expected since both nickel and nickel sulfides behave metallic. Only by assuming a percolation phenomenon that originates from a volume increase of the nickel contacts when reacting to nickel sulfides, this effect can be explained. This assumption was supported by sulfidation tests with differently nickel loaded catalysts and it was quantitatively estimated by a general effective media theory. The single pellet sensor device for in operando investigation of sulfidation can be considered as a valuable tool to get further insights into catalysts under reaction conditions.

Controlled growth of vertically aligned carbon nanotubes on metal substrates

NASA Astrophysics Data System (ADS)

Gao, Zhaoli

Carbon nanotube (CNT) is a fascinating material with extraordinary electrical thermal and mechanical properties. Growing vertically aligned CNT (VACNT) arrays on metal substrates is an important step in bringing CNT into practical applications such as thermal interface materials (TIMs) and microelectrodes. However, the growth process is challenging due to the difficulties in preventing catalyst diffusion and controlling catalyst dewetting on metal substrates with physical surface heterogeneity. In this work, the catalyst diffusion mechanism and catalyst dewetting theory were studied for the controlled growth of VACNTs on metal substrates. The diffusion time of the catalyst, the diffusion coefficients for the catalyst in the substrate materials and the number density of catalyst nanoparticles after dewetting are identified as the key parameters, based on which three strategies are developed. Firstly, a fast-heating catalyst pretreatment strategy was used, aiming at preserving the amount of catalyst prior to CNT growth by reducing the catalyst diffusion time. The catalyst lifetime is extended from half an hour to one hour on a patterned Al thin film and a VACNT height of 106 mum, about twenty fold of that reported in the literature, was attained. Secondly, a diffusion barrier layer strategy is employed for a reduction of catalyst diffusion into the substrate materials. Enhancement of VACNT growth on Cu substrates was achieved by adopting a conformal Al2O 3 diffusion barrier layer fabricated by a specially designed atomic layer deposition (ALD) system. Lastly, a novel catalyst glancing angle deposition (GLAD) strategy is performed to manipulate the morphology of a relatively thick catalyst on metal substrates with physical surface heterogeneity, aiming to obtain uniform and dense catalyst nanoparticles after dewetting in the pretreatment process for enhanced VACNT growth. We are able to control the VACNT growth conditions on metal substrates in terms of their distribution, heights and alignments. Catalyst loss is controlled by the catalyst diffusion time and catalyst diffusion coefficients. A shorter catalyst diffusion time and smaller diffusion coefficient enhance VACNT growth on metals due to reduced catalyst loss during the pretreatment process. The dewetting behaviors of the thin film catalysts are influenced by the physical surface heterogeneity of the substrates which leads to non-uniform growth of VACNTs. The GLAD process facilitates the deposition of a relatively thick catalyst layer for the creation of dense and uniform catalyst nanoparticles. Applications of VACNT-metal structures in TIMs and microelectrodes are demonstrated. The VACNT-TIMs fabricated on Al alloy substrates have a typical thermal contact resistivity of 17.1 mm2˙K/W and their effective application in high-brightness LED thermal management was demonstrated. Electrochemical characterization was carried out on VACNT microelectrodes for the development of high resolution retinal prostheses and a satisfactory electrochemical property was again demonstrated.

Catalysts compositions for use in fuel cells

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

Chuang, Steven S.C.

2015-12-01

The present invention generally relates to the generation of electrical energy from a solid-state fuel. In one embodiment, the present invention relates to a solid-oxide fuel cell for generating electrical energy from a carbon-based fuel, and to catalysts for use in a solid-oxide fuel cell.

Method for producing catalysts from coal

DOEpatents

Farcasiu, M.; Derbyshire, F.; Kaufman, P.B.; Jagtoyen, M.

1998-02-24

A method for producing catalysts from coal is provided comprising mixing an aqueous alkali solution with the coal, heating the aqueous mixture to treat the coal, drying the now-heated aqueous mixture, reheating the mixture to form carbonized material, cooling the mixture, removing excess alkali from the carbonized material, and recovering the carbonized material, wherein the entire process is carried out in controlled atmospheres, and the carbonized material is a hydrocracking or hydrodehalogenation catalyst for liquid phase reactions. The invention also provides for a one-step method for producing catalysts from coal comprising mixing an aqueous alkali solution with the coal to create a mixture, heating the aqueous mixture from an ambient temperature to a predetermined temperature at a predetermined rate, cooling the mixture, and washing the mixture to remove excess alkali from the treated and carbonized material, wherein the entire process is carried out in a controlled atmosphere. 1 fig.

An in situ carbonization-replication method to synthesize mesostructured WO3/C composite as nonprecious-metal anode catalyst in PEMFC.

PubMed

Cui, Xiangzhi; Hua, Zile; Wei, Chenyang; Shu, Zhu; Zhang, Liangxia; Chen, Hangrong; Shi, Jianlin

2013-02-01

A meostructured WO(3)/C composite with crystalline framework and high electric conductivity has been synthesized by a new in situ carbonization-replication route using the block copolymer (poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)) present in situ in the pore channels of mesoporous silica template as carbon source. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, thermogravimetry differential thermal analysis, and N(2) adsorption techniques were adopted for the structural characterization. Cyclic voltammetry, chronoamperometry, and single-cell test for hydrogen electrochemical oxidation were adopted to characterize the electrochemical activities of the mesoporous WO(3)/C composite. The carbon content and consequent electric conductivity of these high-surface-area (108-130 m(2) g(-1)) mesostructured WO(3)/C composite materials can be tuned by variation of the duration of heat treatment, and the composites exhibited high and stable electrochemical catalytic activity. The single-cell test results indicated that the mesostructured WO(3)/C composites showed clear electrochemical catalytic activity toward hydrogen oxidation at 25 °C, which makes them potential non-precious-metal anode catalysts in proton exchange membrane fuel cell. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Non-precious metal catalysts prepared from precursor comprising cyanamide

DOEpatents

Chung, Hoon Taek; Zelenay, Piotr

2015-10-27

Catalyst comprising graphitic carbon and methods of making thereof; said graphitic carbon comprising a metal species, a nitrogen-containing species and a sulfur containing species. A catalyst for oxygen reduction reaction for an alkaline fuel cell was prepared by heating a mixture of cyanamide, carbon black, and a salt selected from an iron sulfate salt and an iron acetate salt at a temperature of from about 700.degree. C. to about 1100.degree. C. under an inert atmosphere. Afterward, the mixture was treated with sulfuric acid at elevated temperature to remove acid soluble components, and the resultant mixture was heated again under an inert atmosphere at the same temperature as the first heat treatment step.

Development of a specimen heating holder with an evaporator and gas injector and its application for catalyst.

PubMed

Takeo, Kamino; Toshie, Yaguchi; Mitsuru, Konno; Akira, Watabe; Yasuhira, Nagakubo

2006-10-01

A specimen heating holder equipped with a gas injector and an evaporator has been developed for use with conventional transmission electron microscopes (TEMs). The developed specimen holder allows both synthesis of metal oxide support and deposition of catalyst nano-particles in situ. Since the holder is designed to be used in small gapped high-resolution objective lens pole-piece, all the procedure from the synthesis of support material to the deposition of catalyst as well as the behavior of the catalyst nano-particles on the support can be observed at near atomic resolution. The developed specimen holder was applied to the study of AuPd catalyst. First, air was injected onto heated aluminum particles via a gas injector to synthesize Al(2)O(3) support. Then, nano-particles of AuPd were deposited on the Al(2)O(3) support. After the deposition, the synthesized Al(2)O(3) support was heated and air was injected again to observe behaviors of the deposited AuPd nano-particles at elevated temperatures in the aerial environment. Behaviors of the AuPd nano-particles such as coalescence, segmentation and diffusion to the Al(2)O(3) support were dynamically observed at atomic level high resolution.

Stack gas treatment

DOEpatents

Reeves, Adam A.

1977-04-12

Hot stack gases transfer contained heat to a gravity flow of pebbles treated with a catalyst, cooled stacked gases and a sulfuric acid mist is withdrawn from the unit, and heat picked up by the pebbles is transferred to air for combustion or other process. The sulfuric acid (or sulfur, depending on the catalyst) is withdrawn in a recovery unit.

Surface Protonics Promotes Catalysis

PubMed Central

Manabe, R.; Okada, S.; Inagaki, R.; Oshima, K.; Ogo, S.; Sekine, Y.

2016-01-01

Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO2 catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando–IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application. Methane was activated by proton collision at the Pd–CeO2 interface, based on the inverse kinetic isotope effect. Proton conduction on the catalyst surface plays an important role in methane activation at low temperature. This report is the first describing promotion of the catalytic reaction by surface protonics. PMID:27905505

Why does the Conductivity of a Nickel Catalyst Increase during Sulfidation? An Exemplary Study Using an In Operando Sensor Device

PubMed Central

Fremerey, Peter; Jess, Andreas; Moos, Ralf

2015-01-01

In order to study the sulfidation of a catalyst fixed bed, an in operando single pellet sensor was designed. A catalyst pellet from the fixed bed was electrically contacted and its electrical response was correlated with the catalyst behavior. For the sulfidation tests, a nickel catalyst was used and was sulfidized with H2S. This catalyst had a very low conductivity in the reduced state. During sulfidation, the conductivity of the catalyst increased by decades. A reaction from nickel to nickel sulfide occurred. This conductivity increase by decades during sulfidation had not been expected since both nickel and nickel sulfides behave metallic. Only by assuming a percolation phenomenon that originates from a volume increase of the nickel contacts when reacting to nickel sulfides, this effect can be explained. This assumption was supported by sulfidation tests with differently nickel loaded catalysts and it was quantitatively estimated by a general effective media theory. The single pellet sensor device for in operando investigation of sulfidation can be considered as a valuable tool to get further insights into catalysts under reaction conditions. PMID:26512669

Method for making polysilsesquioxanes and organohydridosilanes

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

Loy, Douglas A.; Rahimian, Kamyar

2001-01-01

A method for disproportionation of an oligohydridosiloxane to produce a polysilsesquioxane compound and an organohydridosilane compound when contacted with a basic catalyst. The basic catalyst can be a tetraalkylammonium hydroxide, an alkali metal hydroxide, and an alkali earth hydroxide. These basic catalysts are generally dissolved in an organic solvent for delivery. The hydroxide catalysts are attractive because many readily decompose by heating above 150.degree. C., thus being easily removed from the final materials. The oligohydridosiloxane is contacted with the basic catalyst under conditions effective to catalytically convert the oligohydridosiloxane into a polysilsesquioxane compound and an organohydridosilane compound. The reaction canmore » occur in either an inert or oxidative atmosphere and can occur without heating, at room temperature. Both polysilsesquioxane foams and gels of the formula (RSiO.sub.1.5).sub.n can be produced.« less

Compact gasoline fuel processor for passenger vehicle APU

NASA Astrophysics Data System (ADS)

Severin, Christopher; Pischinger, Stefan; Ogrzewalla, Jürgen

Due to the increasing demand for electrical power in today's passenger vehicles, and with the requirements regarding fuel consumption and environmental sustainability tightening, a fuel cell-based auxiliary power unit (APU) becomes a promising alternative to the conventional generation of electrical energy via internal combustion engine, generator and battery. It is obvious that the on-board stored fuel has to be used for the fuel cell system, thus, gasoline or diesel has to be reformed on board. This makes the auxiliary power unit a complex integrated system of stack, air supply, fuel processor, electrics as well as heat and water management. Aside from proving the technical feasibility of such a system, the development has to address three major barriers:start-up time, costs, and size/weight of the systems. In this paper a packaging concept for an auxiliary power unit is presented. The main emphasis is placed on the fuel processor, as good packaging of this large subsystem has the strongest impact on overall size. The fuel processor system consists of an autothermal reformer in combination with water-gas shift and selective oxidation stages, based on adiabatic reactors with inter-cooling. The configuration was realized in a laboratory set-up and experimentally investigated. The results gained from this confirm a general suitability for mobile applications. A start-up time of 30 min was measured, while a potential reduction to 10 min seems feasible. An overall fuel processor efficiency of about 77% was measured. On the basis of the know-how gained by the experimental investigation of the laboratory set-up a packaging concept was developed. Using state-of-the-art catalyst and heat exchanger technology, the volumes of these components are fixed. However, the overall volume is higher mainly due to mixing zones and flow ducts, which do not contribute to the chemical or thermal function of the system. Thus, the concept developed mainly focuses on minimization of those component volumes. Therefore, the packaging utilizes rectangular catalyst bricks and integrates flow ducts into the heat exchangers. A concept is presented with a 25 l fuel processor volume including thermal isolation for a 3 kW el auxiliary power unit. The overall size of the system, i.e. including stack, air supply and auxiliaries can be estimated to 44 l.

Fuel processor for fuel cell power system

DOEpatents

Vanderborgh, Nicholas E.; Springer, Thomas E.; Huff, James R.

1987-01-01

A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

A flow-pulse adsorption-microcalorimetry system for studies of adsorption processes on powder catalysts

NASA Astrophysics Data System (ADS)

You, Rui; Li, Zhaorui; Zeng, Hongyu; Huang, Weixin

2018-06-01

A pulse chemisorption system combining a Tian-Calvet microcalorimeter (Setaram Sensys EVO 600) and an automated chemisorption apparatus (Micromeritics Autochem II 2920) was established to accurately measure differential adsorption heats of gas molecules' chemisorption on solid surfaces in a flow-pulse mode. Owing to high sensitivity and high degree of automation in a wide range of temperatures from -100 to 600 °C, this coupled system can present adsorption heats as a function of adsorption temperature and adsorbate coverage. The functions of this system were demonstrated by successful measurements of CO adsorption heats on Pd surfaces at various temperatures and also at different CO coverages by varying the CO concentration in the pulse dose. Key parameters, including adsorption amounts, integral adsorption heats, and differential adsorption heats of CO adsorption on a Pd/CeO2 catalyst, were acquired. Our adsorption-microcalorimetry system provides a powerful technique for the investigation of adsorption processes on powder catalysts.

Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging.

PubMed

Howe, Jane Y; Allard, Lawrence F; Bigelow, Wilbur C; Demers, Hendrix; Overbury, Steven H

2014-01-01

By coupling techniques of simultaneous secondary (SE) and transmitted electron (TE) imaging at high resolution in a modern scanning transmission electron microscope (STEM), with the ability to heat specimens using a highly stable MEMS-based heating platform, we obtained synergistic information to clarify the behavior of catalysts during in situ thermal treatments. Au/iron oxide catalyst 'leached' to remove surface Au was heated to temperatures as high as 700°C. The Fe2O3 support particle structure tended to reduce to Fe3O4 and formed surface terraces; the formation, coalescence, and mobility of 1- to 2-nm particles on the terraces were characterized in SE, STEM-ADF, and TEM-BF modes. If combined with simultaneous nanoprobe spectroscopy, this approach will open the door to a new way of studying the kinetics of nano-scaled phenomena.

Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging

NASA Astrophysics Data System (ADS)

Howe, Jane Y.; Allard, Lawrence F.; Bigelow, Wilbur C.; Demers, Hendrix; Overbury, Steven H.

2014-11-01

By coupling techniques of simultaneous secondary (SE) and transmitted electron (TE) imaging at high resolution in a modern scanning transmission electron microscope (STEM), with the ability to heat specimens using a highly stable MEMS-based heating platform, we obtained synergistic information to clarify the behavior of catalysts during in situ thermal treatments. Au/iron oxide catalyst 'leached' to remove surface Au was heated to temperatures as high as 700°C. The Fe2O3 support particle structure tended to reduce to Fe3O4 and formed surface terraces; the formation, coalescence, and mobility of 1- to 2-nm particles on the terraces were characterized in SE, STEM-ADF, and TEM-BF modes. If combined with simultaneous nanoprobe spectroscopy, this approach will open the door to a new way of studying the kinetics of nano-scaled phenomena.

Microstructural observation of fuel cell catalyst inks by Cryo-SEM and Cryo-TEM.

PubMed

Shimanuki, Junichi; Takahashi, Shinichi; Tohma, Hajime; Ohma, Atsushi; Ishihara, Ayumi; Ito, Yoshiko; Nishino, Yuri; Miyazawa, Atsuo

2017-06-01

In order to improve the electricity generation performance of fuel cell electric vehicles, it is necessary to optimize the microstructure of the catalyst layer of a polymer electrolyte fuel cell. The catalyst layer is formed by a wet coating process using catalyst inks. Therefore, it is very important to observe the microstructure of the catalyst ink. In this study, the morphology of carbon-supported platinum (Pt/C) particles in catalyst inks with a different solvent composition was investigated by cryogenic scanning electron microscopy (cryo-SEM). In addition, the morphology of the ionomer, which presumably influences the formation of agglomerated Pt/C particles in a catalyst ink, was investigated by cryogenic transmission electron microscopy (cryo-TEM). The results of a cryo-SEM observation revealed that the agglomerated Pt/C particles tended to become coarser with a higher 1-propanol (NPA) weight fraction. The results of a cryo-TEM observation indicated that the actual ionomer dispersion in a catalyst ink formed a network structure different from that of the ionomer in the solvent. © The Author 2017. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of Nd-, Pr-, Tb- and Y-doping on the structural, textural, electrical and N2O decomposition activity of mesoporous NiO nanoparticles

NASA Astrophysics Data System (ADS)

Abu-Zied, Bahaa M.; Bawaked, Salem M.; Kosa, Samia A.; Ali, Tarek T.; Schwieger, Wilhelm; Aqlan, Faisal M.

2017-10-01

Recently, nickel oxide, NiO, promoted with various dopants showed an interesting activity behavior in N2O direct decomposition. In this paper, the activity of a series of rare earth (Nd, Pr, Tb and Y) doped NiO catalysts was investigated for this reaction. These catalysts have been prepared by the calcination of their corresponding oxalate mixtures, which have been synthesized via the microwave-assisted precipitation route using oxalic acid as precipitant. Characterization of the obtained catalysts was carried out by using various physico-chemical techniques including TGA, FT-IR, XRD, FE-SEM, TEM, TPR, XPS and electrical conductivity. The results obtained revealed the nanocrystalline nature of the prepared catalysts. Moreover, the presence of the various dopants has led to a noticeable decrease of the NiO crystallites size, mesoporosity development and an increase of its surface area and pore volume. There is a substantial activity increase upon doping NiO with the various rare earth oxides. Such activity increase is associated with the structural modifications as well as the electrical conductivity increase of these catalysts.

Steam reformer with catalytic combustor

DOEpatents

Voecks, Gerald E.

1990-03-20

A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

Steam reformer with catalytic combustor

NASA Technical Reports Server (NTRS)

Voecks, Gerald E. (Inventor)

1990-01-01

A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

Fuel processor for fuel cell power system. [Conversion of methanol into hydrogen

DOEpatents

Vanderborgh, N.E.; Springer, T.E.; Huff, J.R.

1986-01-28

A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

Heat and fuel coupled operation of a high temperature polymer electrolyte fuel cell with a heat exchanger methanol steam reformer

NASA Astrophysics Data System (ADS)

Schuller, G.; Vázquez, F. Vidal; Waiblinger, W.; Auvinen, S.; Ribeirinha, P.

2017-04-01

In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al2O3 (BASF RP-60) catalyst. The liquid cooled, 165 cm2, 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 Wel. A total stack waste heat utilization of 86.4% was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

Process of activation of a palladium catalyst system

DOEpatents

Sobolevskiy, Anatoly [Orlando, FL; Rossin, Joseph A [Columbus, OH; Knapke, Michael J [Columbus, OH

2011-08-02

Improved processes for activating a catalyst system used for the reduction of nitrogen oxides are provided. In one embodiment, the catalyst system is activated by passing an activation gas stream having an amount of each of oxygen, water vapor, nitrogen oxides, and hydrogen over the catalyst system and increasing a temperature of the catalyst system to a temperature of at least 180.degree. C. at a heating rate of from 1-20.degree./min. Use of activation processes described herein leads to a catalyst system with superior NOx reduction capabilities.

Heat pipe methanator

DOEpatents

Ranken, William A.; Kemme, Joseph E.

1976-07-27

A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test... efficiency. The thermal stress is imposed on the test catalyst by exposing it to quiescent heated air in an... that the catalyst being tested was not designed to reduce/oxidize. The engine manufacturer must specify...

40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test... efficiency. The thermal stress is imposed on the test catalyst by exposing it to quiescent heated air in an... that the catalyst being tested was not designed to reduce/oxidize. The engine manufacturer must specify...

40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test... efficiency. The thermal stress is imposed on the test catalyst by exposing it to quiescent heated air in an... that the catalyst being tested was not designed to reduce/oxidize. The engine manufacturer must specify...

40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test... efficiency. The thermal stress is imposed on the test catalyst by exposing it to quiescent heated air in an... that the catalyst being tested was not designed to reduce/oxidize. The engine manufacturer must specify...

40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test... efficiency. The thermal stress is imposed on the test catalyst by exposing it to quiescent heated air in an... that the catalyst being tested was not designed to reduce/oxidize. The engine manufacturer must specify...

Electric field tuned MoS2/metal interface for hydrogen evolution catalyst from first-principles investigations

NASA Astrophysics Data System (ADS)

Ling, F. L.; Zhou, T. W.; Liu, X. Q.; Kang, W.; Zeng, W.; Zhang, Y. X.; Fang, L.; Lu, Y.; Zhou, M.

2018-01-01

Understanding the interfacial properties of catalyst/substrate is crucial for the design of high-performance catalyst for important chemical reactions. Recent years have witnessed a surge of research in utilizing MoS2 as a promising electro-catalyst for hydrogen production, and field effect has been employed to enhance the activity (Wang et al 2017 Adv. Mater. 29, 1604464; Yan et al 2017 Nano Lett. 17, 4109-15). However, the underlying atomic mechanism remains unclear. In this paper, by using the prototype MoS2/Au system as a probe, we investigate effects of external electric field on the interfacial electronic structures via density functional theory (DFT) based first-principles calculations. Our results reveal that although there is no covalent interaction between MoS2 overlayer and Au substrate, an applied electric field efficiently adjusts the charge transfer between MoS2 and Au, leading to tunable Schottky barrier type (n-type to p-type) and decrease of barrier height to facilitate charge injection. Furthermore, we predict that the adsorption energy of atomic hydrogen on MoS2/Au to be readily controlled by electric field to a broad range within a modest magnitude of field, which may benefit the performance enhancement of hydrogen evolution reaction. Our DFT results provide valuable insight into the experimental observations and pave the way for future understanding and control of catalysts in practice, such as those with vacancies, defects, edge states or synthesized nanostructures.

Preliminary results from screening tests of commercial catalysts with potential use in gas turbine combustors. Part 1: Furnace studies of catalyst activity

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1976-01-01

Thirty commercially produced monolith and pellet catalysts were tested as part of a screening process to select catalysts suitable for use in a gas turbine combustor. The catalysts were contained in a 1.8 centimeter diameter quartz tube and heated to temperatures varying between 300 and 1,200 K while a mixture of propane and air passed through the bed at space velocities of 44,000 to 70,000/hour. The amount of propane oxidized was measured as a function of catalyst temperature. Of the samples tested, the most effective catalysts proved to be noble metal catalysts on monolith substrates.

An optimization study of PtSn/C catalysts applied to direct ethanol fuel cell: Effect of the preparation method on the electrocatalytic activity of the catalysts

NASA Astrophysics Data System (ADS)

Almeida, T. S.; Palma, L. M.; Leonello, P. H.; Morais, C.; Kokoh, K. B.; De Andrade, A. R.

2012-10-01

The aim of this work was to perform a systematic study of the parameters that can influence the composition, morphology, and catalytic activity of PtSn/C nanoparticles and compare two different methods of nanocatalyst preparation, namely microwave-assisted heating (MW) and thermal decomposition of polymeric precursors (DPP). An investigation of the effects of the reducing and stabilizing agents on the catalytic activity and morphology of Pt75Sn25/C catalysts prepared by microwave-assisted heating was undertaken for optimization purposes. The effect of short-chain alcohols such as ethanol, ethylene glycol, and propylene glycol as reducing agents was evaluated, and the use of sodium acetate and citric acid as stabilizing agents for the MW procedure was examined. Catalysts obtained from propylene glycol displayed higher catalytic activity compared with catalysts prepared in ethylene glycol. Introduction of sodium acetate enhanced the catalytic activity, but this beneficial effect was observed until a critical acetate concentration was reached. Optimization of the MW synthesis allowed for the preparation of highly dispersed catalysts with average sizes lying between 2.0 and 5.0 nm. Comparison of the best catalyst prepared by MW with a catalyst of similar composition prepared by the polymeric precursors method showed that the catalytic activity of the material can be improved when a proper condition for catalyst preparation is achieved.

Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging

DOE PAGES

Howe, Jane Y.; Allard, Jr., Lawrence Frederick; Demers, Hendrix; ...

2014-11-14

In situ heating study via a simultaneous secondary electron (SE) and transmitted electron (TE) microscopy is extremely insightful because information from the surface (SE) and bulk (TE) can be readily obtained. The leached Au/Fe 2O 3 catalyst has voids on the surface of Fe 2O 3. Upon heating to 500 °C, voids shrank and disappeared, while internal Au species diffused to the surface to form new nanoparticles. Heating in vacuum reduced Fe 2O 3 to Fe 3O 4. Heating at 700 °C caused coalescence and growth of Au particles and formation of faceted Fe 3O 4 surfaces. We achieved 1.1more » nm resolution in SE imaging during in situ heating.« less

hcp-Co nanowires grown on metallic foams as catalysts for the Fischer-Tropsch synthesis.

PubMed

Soulantica, Katerina; Harmel, Justine; Peres, Laurent; Estrader, Marta; Berliet, Adrien; Maury, Sylvie; Fécant, Antoine; Chaudret, Bruno; Serp, Philippe

2018-06-12

The possibility to control the structural characteristics of the active phase of supported catalysts offers the opportunity to improve catalyst performance, especially in structure sensitive catalytic reactions. In parallel, heat management is of critical importance for the catalytic performance in highly endo- or exothermic reactions. The Fisher-Tropsch synthesis (FTS) is a structure sensitive exothermic reaction, which enables catalytic transformation of syngas to high quality liquid fuels. We have elaborated monolithic cobalt based heterogeneous catalysts through a wet chemistry approach that allows control over nanocrystal shape and crystallographic phase, while at the same time enables heat management. Copper and nickel foams have been employed as supports for the epitaxial growth of hcp-Co nanowires, directly from a solution containing a coordination compound of cobalt and stabilizing ligands. The Co/Cufoam catalyst has been tested for the Fischer-Tropsch synthesis in fixed bed reactor, showing stability, and significantly superior activity and selectivity towards C5+ compared to a Co/SiO2-Al2O3 reference catalyst under the same conditions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In-situ X-ray diffraction activation study on an Fe/TiO2 pre-catalyst.

PubMed

Rayner, Matthew K; Billing, David G; Coville, Neil J

2014-06-01

This study focuses on the use of in situ powder X-ray diffraction (PXRD) and quantitative phase analysis using the Rietveld method to monitor the structural properties of a titania-supported iron (10% Fe/TiO2) pre-catalyst during calcination (oxidation) and activation (reduction) in the temperature range 25-900°C. The TiO2 oxidation study revealed an increase in anatase particle size before the anatase to rutile phase transformation, lending credibility to the bridging mechanism proposed by Kim et al. [(2007), Mater. Sci. Forum, 534-536, 65-68]. Pre-catalyst oxidation experiments allowed for the determination of a suitable calcination temperature (450°C) of the pre-catalyst in terms of maximum hematite concentration and appropriate particle size. These experiments also confirmed that the anatase to rutile phase transformation occurred at higher temperatures after Fe addition and that anatase was the sole donor of Ti(4+) ions, which are known to migrate into hematite (Gennari et al., 1998), during the formation of pseudobrookite (Fe2TiO5) at temperatures above 690°C. Using the results from the oxidation experiments, two pre-catalyst samples were calcined at different temperatures; one to represent the preferred case and one to represent a case where the pre-catalyst had been excessively heated. Samples of the excessively heated catalysts were exposed to different reducing gas atmospheres (5, 10 and 100% H2/N2) and heated in the in situ PXRD reactor, so that diffraction data could be collected during the activation process. The results show that reduction with gases containing low concentrations of H2 (5 and 10%) led to the formation of ilmenite (FeTiO3) and we were able to show that both anatase and rutile are consumed in the reaction. Higher concentrations of H2 led to the formation of magnetite (Fe3O4) and metallic iron (Fe(0)). We also noted a decrease in the anatase to rutile transformation temperature under reducing atmospheres when compared with the pre-catalyst heat-treatment experiment. A reduced calcination temperature prior to reduction allowed more facile Fe reduction.

Theoretical and Experimental Study of Thermoacoustic Engines

DTIC Science & Technology

1991-12-31

possible. In particulbr, we have considered use of extruded ceramic monolithic catalyst supports (for example, the ceramic used in some automobile...approximation. Heat exchangers retaken r be of negligible thickness and thus not to affect near-standing wave phasing. The TAB (or snack ) of length d is assumed...Heat exchangers were parallel plates of copper and the TAE is a monolithic catalyst support extruded ceramic. 13 15 The two-microphone-technique

Mercury oxidation promoted by a selective catalytic reduction catalyst under simulated Powder River Basin coal combustion conditions.

PubMed

Lee, Chun W; Serre, Shannon D; Zhao, Yongxin; Lee, Sung Jun; Hastings, Thomas W

2008-04-01

A bench-scale reactor consisting of a natural gas burner and an electrically heated reactor housing a selective catalytic reduction (SCR) catalyst was constructed for studying elemental mercury (Hg(o)) oxidation under SCR conditions. A low sulfur Powder River Basin (PRB) subbituminous coal combustion fly ash was injected into the entrained-flow reactor along with sulfur dioxide (SO2), nitrogen oxides (NOx), hydrogen chloride (HCl), and trace Hg(o). Concentrations of Hg(o) and total mercury (Hg) upstream and downstream of the SCR catalyst were measured using a Hg monitor. The effects of HCl concentration, SCR operating temperature, catalyst space velocity, and feed rate of PRB fly ash on Hg(o) oxidation were evaluated. It was observed that HCl provides the source of chlorine for Hg(o) oxidation under simulated PRB coal-fired SCR conditions. The decrease in Hg mass balance closure across the catalyst with decreasing HCl concentration suggests that transient Hg capture on the SCR catalyst occurred during the short test exposure periods and that the outlet speciation observed may not be representative of steady-state operation at longer exposure times. Increasing the space velocity and operating temperature of the SCR led to less Hg(o) oxidized. Introduction of PRB coal fly ash resulted in slightly decreased outlet oxidized mercury (Hg2+) as a percentage of total inlet Hg and correspondingly resulted in an incremental increase in Hg capture. The injection of ammonia (NH3) for NOx reduction by SCR was found to have a strong effect to decrease Hg oxidation. The observations suggest that Hg(o) oxidation may occur near the exit region of commercial SCR reactors. Passage of flue gas through SCR systems without NH3 injection, such as during the low-ozone season, may also impact Hg speciation and capture in the flue gas.

Improved water electrolysis using magnetic heating of FeC-Ni core-shell nanoparticles

NASA Astrophysics Data System (ADS)

Niether, Christiane; Faure, Stéphane; Bordet, Alexis; Deseure, Jonathan; Chatenet, Marian; Carrey, Julian; Chaudret, Bruno; Rouet, Alain

2018-06-01

Water electrolysis enables the storage of renewable electricity via the chemical bonds of hydrogen. However, proton-exchange-membrane electrolysers are impeded by the high cost and low availability of their noble-metal electrocatalysts, whereas alkaline electrolysers operate at a low power density. Here, we demonstrate that electrocatalytic reactions relevant for water splitting can be improved by employing magnetic heating of noble-metal-free catalysts. Using nickel-coated iron carbide nanoparticles, which are prone to magnetic heating under high-frequency alternating magnetic fields, the overpotential (at 20 mA cm-2) required for oxygen evolution in an alkaline water-electrolysis flow-cell was decreased by 200 mV and that for hydrogen evolution was decreased by 100 mV. This enhancement of oxygen-evolution kinetics is equivalent to a rise of the cell temperature to 200 °C, but in practice it increased by 5 °C only. This work suggests that, in the future, water splitting near the equilibrium voltage could be possible at room temperature, which is currently beyond reach in the classic approach to water electrolysis.

Dosimeter-Type NOx Sensing Properties of KMnO4 and Its Electrical Conductivity during Temperature Programmed Desorption

PubMed Central

Groβ, Andrea; Kremling, Michael; Marr, Isabella; Kubinski, David J.; Visser, Jacobus H.; Tuller, Harry L.; Moos, Ralf

2013-01-01

An impedimetric NOx dosimeter based on the NOx sorption material KMnO4 is proposed. In addition to its application as a low level NOx dosimeter, KMnO4 shows potential as a precious metal free lean NOx trap material (LNT) for NOx storage catalysts (NSC) enabling electrical in-situ diagnostics. With this dosimeter, low levels of NO and NO2 exposure can be detected electrically as instantaneous values at 380 °C by progressive NOx accumulation in the KMnO4 based sensitive layer. The linear NOx sensing characteristics are recovered periodically by heating to 650 °C or switching to rich atmospheres. Further insight into the NOx sorption-dependent conductivity of the KMnO4-based material is obtained by the novel eTPD method that combines electrical characterization with classical temperature programmed desorption (TPD). The NOx loading amount increases proportionally to the NOx exposure time at sorption temperature. The cumulated NOx exposure, as well as the corresponding NOx loading state, can be detected linearly by electrical means in two modes: (1) time-continuously during the sorption interval including NOx concentration information from the signal derivative or (2) during the short-term thermal NOx release. PMID:23549366

Self regulating formulations for safe hydrogen gettering

DOEpatents

Shepodd, Timothy Jon

2002-01-01

A method and composition are disclosed for preventing uncontrolled exothermic reaction in the presence of a catalyst. A catalyst deployed as a finely divided powder which is attached to the surface of a low melting point wax or wax-like material which is utilized as a carrier for the catalyst. During operation should the catalyst overheat due to uncontrolled conditions brought about by a run-away reaction the heat of reaction melts the low melting point wax which would itself wet the surface of the catalyst and prevent further catalysis.

Synthesis of highly aligned carbon nanotubes by one-step liquid-phase process: Effects of carbon sources on morphology of carbon nanotubes

NASA Astrophysics Data System (ADS)

Yamagiwa, Kiyofumi; Kuwano, Jun

2017-06-01

This paper describes a unique and innovative synthesis technique for carbon nanotubes (CNTs) by a one-step liquid-phase process under ambient pressure. Vertically aligned multi-walled CNT arrays with a maximum height of 100 µm are prepared on stainless steel substrates, which are submerged and electrically heated in straight-chain primary alcohols with n C = 1-4 (n C: number of C atoms in the molecule) containing an appropriate amount of cobalt-based organometallic complex as a catalyst precursor. Structural isomers of butanol were also used for the synthesis to examine the effects of structural factors on the morphology of the deposited products. Notably, 2-methyl-2-propanol, which is a tertiary alcohol, produced only a small amount of low-crystallinity carbonaceous deposits, whereas vertically aligned CNTs were grown from the other isomers of butanol. These results suggest that the presence or absence of β-hydrogen in the molecular structure is a key factor for understanding the dissociation behavior of the carbon source molecules on the catalyst.

Microcombustor

DOEpatents

Gardner, Timothy J.; Manginelli, Ronald P.; Lewis, Patrick R.; Frye-Mason, Gregory C.; Colburn, Chris

2004-09-07

A microcombustor comprises a microhotplate and a catalyst for sustained combustion on the microscale. The microhotplate has very low heat capacity and thermal conductivity that mitigate large heat losses arising from large surface-to-volume ratios typical of the microdomain. The heated catalyst enables flame ignition and stabilization, permits combustion with lean fuel/air mixtures, extends a hydrocarbon's limits of flammability, and lowers the combustion temperature. The reduced operating temperatures enable a longer microcombustor lifetime and the reduced fuel consumption enables smaller fuel supplies, both of which are especially important for portable microsystems applications. The microcombustor can be used for on-chip thermal management and for sensor applications, such as heating of a micro gas chromatography column and for use as a micro flame ionization detector.

Method for producing catalysis from coal

DOEpatents

Farcasiu, Malvina; Derbyshire, Frank; Kaufman, Phillip B.; Jagtoyen, Marit

1998-01-01

A method for producing catalysts from coal is provided comprising mixing an aqueous alkali solution with the coal, heating the aqueous mixture to treat the coal, drying the now-heated aqueous mixture, reheating the mixture to form carbonized material, cooling the mixture, removing excess alkali from the carbonized material, and recovering the carbonized material, wherein the entire process is carried out in controlled atmospheres, and the carbonized material is a hydrocracking or hydrodehalogenation catalyst for liquid phase reactions. The invention also provides for a one-step method for producing catalysts from coal comprising mixing an aqueous alkali solution with the coal to create a mixture, heating the aqueous mixture from an ambient temperature to a predetermined temperature at a predetermined rate, cooling the mixture, and washing the mixture to remove excess alkali from the treated and carbonized material, wherein the entire process is carried out in a controlled atmosphere.

Method and apparatus for controlling accidental releases of tritium

DOEpatents

Galloway, T.R.

1980-04-01

An improvement is described in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release. 1 fig.

Method and apparatus for controlling accidental releases of tritium

DOEpatents

Galloway, Terry R. [Berkeley, CA

1980-04-01

An improvement in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release.

Process for metallization of a substrate by curing a catalyst applied thereto

DOEpatents

Chen, Ken S.; Morgan, William P.; Zich, John L.

2002-10-08

An improved additive process for metallization of substrates is described whereby a catalyst solution is applied to a surface of a substrate. Metallic catalytic clusters can be formed in the catalyst solution on the substrate surface by heating the substrate. Electroless plating can then deposit metal onto the portion of the substrate surface coated with catalyst solution. Additional metallization thickness can be obtained by electrolytically plating the substrate surface after the electroless plating step.

Molecular Monolayers for Electrical Passivation and Functionalization of Silicon-Based Solar Energy Devices.

PubMed

Veerbeek, Janneke; Firet, Nienke J; Vijselaar, Wouter; Elbersen, Rick; Gardeniers, Han; Huskens, Jurriaan

2017-01-11

Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based solar cells. Organic monolayers were coupled to silicon surfaces by hydrosilylation in order to avoid an insulating silicon oxide layer at the surface. Monolayers of 1-tetradecyne were shown to passivate silicon micropillar-based solar cells with radial junctions, by which the efficiency increased from 8.7% to 9.9% for n + /p junctions and from 7.8% to 8.8% for p + /n junctions. This electrical passivation of the surface, most likely by removal of dangling bonds, is reflected in a higher shunt resistance in the J-V measurements. Monolayers of 1,8-nonadiyne were still reactive for click chemistry with a model catalyst, thus enabling simultaneous passivation and future catalyst coupling.

Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers: Innovative Clean Coal Technology (ICCT)

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

Not Available

1992-05-01

The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the amonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japanmore » and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO, and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal. The demonstration will be performed at Gulf Power Company's Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project will be funded by the US Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), and the Electric Power Research Institute.« less

Visible light plasmonic heating of Au-ZnO for the catalytic reduction of CO 2

DOE PAGES

Wang, Congjun; Ranasingha, Oshadha; Natesakhawat, Sittichai; ...

2013-01-01

Plasmonic excitation of Au nanoparticles attached to the surface of ZnO catalysts using low power 532 nm laser illumination leads to significant heating of the catalyst and the conversion of CO 2 and H 2 reactants to CH 4 and CO products. Temperature-calibrated Raman spectra of ZnO phonons show that intensity-dependent plasmonic excitation can controllably heat Au–ZnO from 30 to ~600 °C and simultaneously tune the CH 4 : CO product ratio. The laser induced heating and resulting CH 4 : CO product distribution agrees well with predictions from thermodynamic models and temperature-programmed reaction experiments indicating that the reaction ismore » a thermally driven process resulting from the plasmonic heating of the Au-ZnO. The apparent quantum yield for CO 2 conversion under continuous wave (cw) 532 nm laser illumination is 0.030%. The Au-ZnO catalysts are robust and remain active after repeated laser exposure and cycling. The light intensity required to initiate CO 2 reduction is low ( ~2.5 x 10 5 W m -2) and achievable with solar concentrators. Our results illustrate the viability of plasmonic heating approaches for CO 2 utilization and other practical thermal catalytic applications.« less

Composition and method for polymer moderated catalytic water formation

DOEpatents

Shepodd, Timothy Jon

1999-01-01

A composition suitable for safely removing hydrogen from gaseous mixtures containing hydrogen and oxygen, particularly those mixtures wherein the hydrogen concentration is within the explosive range. The composition comprises a hydrogenation catalyst, preferably Pd dispersed on carbon, wherein the concentration of Pd is from about 1-10 wt %, dispersed in a polymeric material matrix. As well as serving as a matrix to contain the hydrogenation catalyst, the polymeric material, which is substantially unreactive to hydrogen, provides both a diffusion restriction to hydrogen and oxygen, thereby limiting the rate at which the reactants (hydrogen and oxygen) can diffuse to the catalyst surface and thus, the production of heat from the recombination reaction and as a heat sink.

Carbon-free H2 production from ammonia triggered at room temperature with an acidic RuO2/γ-Al2O3 catalyst.

PubMed

Nagaoka, Katsutoshi; Eboshi, Takaaki; Takeishi, Yuma; Tasaki, Ryo; Honda, Kyoko; Imamura, Kazuya; Sato, Katsutoshi

2017-04-01

Ammonia has been suggested as a carbon-free hydrogen source, but a convenient method for producing hydrogen from ammonia with rapid initiation has not been developed. Ideally, this method would require no external energy input. We demonstrate hydrogen production by exposing ammonia and O 2 at room temperature to an acidic RuO 2 /γ-Al 2 O 3 catalyst. Because adsorption of ammonia onto the catalyst is exothermic, the catalyst bed is rapidly heated to the catalytic ammonia autoignition temperature, and subsequent oxidative decomposition of ammonia produces hydrogen. A differential calorimeter combined with a volumetric gas adsorption analyzer revealed a large quantity of heat evolved both with chemisorption of ammonia onto RuO 2 and acidic sites on the γ-Al 2 O 3 and with physisorption of multiple ammonia molecules.

Carbon-free H2 production from ammonia triggered at room temperature with an acidic RuO2/γ-Al2O3 catalyst

PubMed Central

Nagaoka, Katsutoshi; Eboshi, Takaaki; Takeishi, Yuma; Tasaki, Ryo; Honda, Kyoko; Imamura, Kazuya; Sato, Katsutoshi

2017-01-01

Ammonia has been suggested as a carbon-free hydrogen source, but a convenient method for producing hydrogen from ammonia with rapid initiation has not been developed. Ideally, this method would require no external energy input. We demonstrate hydrogen production by exposing ammonia and O2 at room temperature to an acidic RuO2/γ-Al2O3 catalyst. Because adsorption of ammonia onto the catalyst is exothermic, the catalyst bed is rapidly heated to the catalytic ammonia autoignition temperature, and subsequent oxidative decomposition of ammonia produces hydrogen. A differential calorimeter combined with a volumetric gas adsorption analyzer revealed a large quantity of heat evolved both with chemisorption of ammonia onto RuO2 and acidic sites on the γ-Al2O3 and with physisorption of multiple ammonia molecules. PMID:28508046

Deconstruction of lignocellulosic biomass with hydrated cerium (III) chloride in water and ethanol

DOE PAGES

Akalin, Mehmet K.; Das, Parthapratim; Alper, Koray; ...

2017-08-08

Lignocellulosic biomass was decomposed to produce crude bio-oil in water and ethanol using hydrated cerium (III) chloride as a catalyst. Use of the catalyst affected not only the yield of crude bio-oil but also the composition of bio-crude for both water and ethanol. The catalyst had a detrimental effect on the crude bio-oil yields obtained from water processing for all runs. However, in ethanol, use of the catalyst improved the crude bio-oil yields in all tested runs. The solid residue yields decreased with the catalyst use in the runs with water but increased in all studies with ethanol, except thosemore » with the shortest tested residence time of 10 min. The highest crude bio-oil yield of 48.2 wt% was obtained at 300 °C using 5 mmol of hydrated cerium (III) chloride at a residence time of 90 min in ethanol. The heating values of the crude bio-oils increased with the catalyst use for both water and ethanol processing. In conclusion, the highest heating value of 33.3 MJ kg –1 was obtained with hydrated cerium (III) chloride at 300 °C and a residence time of 120 min.« less

Deconstruction of lignocellulosic biomass with hydrated cerium (III) chloride in water and ethanol

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

Akalin, Mehmet K.; Das, Parthapratim; Alper, Koray

Lignocellulosic biomass was decomposed to produce crude bio-oil in water and ethanol using hydrated cerium (III) chloride as a catalyst. Use of the catalyst affected not only the yield of crude bio-oil but also the composition of bio-crude for both water and ethanol. The catalyst had a detrimental effect on the crude bio-oil yields obtained from water processing for all runs. However, in ethanol, use of the catalyst improved the crude bio-oil yields in all tested runs. The solid residue yields decreased with the catalyst use in the runs with water but increased in all studies with ethanol, except thosemore » with the shortest tested residence time of 10 min. The highest crude bio-oil yield of 48.2 wt% was obtained at 300 °C using 5 mmol of hydrated cerium (III) chloride at a residence time of 90 min in ethanol. The heating values of the crude bio-oils increased with the catalyst use for both water and ethanol processing. In conclusion, the highest heating value of 33.3 MJ kg –1 was obtained with hydrated cerium (III) chloride at 300 °C and a residence time of 120 min.« less

Activity and Stability of Dispersed Multi Metallic Pt-based Catalysts for CO Tolerance in Proton Exchange Membrane Fuel Cell Anodes.

PubMed

Hassan, Ayaz; Ticianelli, Edson A

2018-01-01

Studies aiming at improving the activity and stability of dispersed W and Mo containing Pt catalysts for the CO tolerance in proton exchange membrane fuel cell (PEMFC) anodes are revised for the following catalyst systems: (1) a carbon supported PtMo electrocatalyst submitted to heat treatments; (2) Pt and PtMo nanoparticles deposited on carbon-supported molybdenum carbides (Mo2C/C); (3) ternary and quaternary materials formed by PtMoFe/C, PtMoRu/C and PtMoRuFe/C and; (4) Pt nanoparticles supported on tungsten carbide/carbon catalysts and its parallel evaluation with carbon supported PtW catalyst. The heat-treated (600 oC) Pt-Mo/C catalyst showed higher hydrogen oxidation activity in the absence and in the presence of CO and better stability, compared to all other Mo-containing catalysts. PtMoRuFe, PtMoFe, PtMoRu supported on carbon and Pt supported on Mo2C/C exhibited similar CO tolerances but better stability, as compared to as-prepared PtMo supported on carbon. Among the tungsten-based catalysts, tungsten carbide supported Pt catalyst showed reasonable performance and reliable stability in comparison to simple carbon supported PtW catalyst, though an uneven level of catalytic activity towards H2 oxidation in presence of CO is observed for the former as compared to Mo containing catalyst. However, a small dissolution of Mo, Ru, Fe and W from the anodes and their migration toward cathodes during the cell operation is observed. These results indicate that the fuel cell performance and stability has been improved but not yet totally resolved.

Mathematical Model of Heat Transfer in the Catalyst Granule with Point Reaction Centers

NASA Astrophysics Data System (ADS)

Derevich, I. V.; Fokina, A. Yu.

2018-01-01

This paper considers a catalyst granule with a porous ceramic chemically inert base and active point centers, at which an exothermic reaction of synthesis takes place. The rate of a chemical reaction depends on temperature by the Arrhenius law. The heat is removed from the catalyst granule surface to the synthesis products by heat transfer. Based on the idea of self-consistent field, a closed system of equations is constructed for calculating the temperatures of the active centers. As an example, a catalyst granule of the Fischer-Tropsch synthesis with active metallic cobalt particles is considered. The stationary temperatures of the active centers are calculated by the timedependent technique by solving a system of ordinary differential equations. The temperature distribution inside the granule has been found for the local centers located on one diameter of the granule and distributed randomly in the granule's volume. The existence of the critical temperature inside the reactor has been established, the excess of which leads to substantial superheating of local centers. The temperature distribution with local reaction centers differs qualitatively from the granule temperature calculated in the homogeneous approximation. The results of calculations are given.

Formic acid fuel cells and catalysts

DOEpatents

Masel, Richard I.; Larsen, Robert; Ha, Su Yun

2010-06-22

An exemplary fuel cell of the invention includes a formic acid fuel solution in communication with an anode (12, 134), an oxidizer in communication with a cathode (16, 135) electrically linked to the anode, and an anode catalyst that includes Pd. An exemplary formic acid fuel cell membrane electrode assembly (130) includes a proton-conducting membrane (131) having opposing first (132) and second surfaces (133), a cathode catalyst on the second membrane surface, and an anode catalyst including Pd on the first surface.

Directed Growth of Carbon Nanotubes Across Gaps

NASA Technical Reports Server (NTRS)

Delzeit, Lance; Meyyapan, Meyya

2008-01-01

An experiment has shown that when single-walled carbon nanotubes (SWNTs) are grown by chemical vapor deposition in the presence of an electric field of suitable strength, the nanotubes become aligned along the electric field. In an important class of contemplated applications, one would exploit this finding in fabricating nanotube transistors; one would grow SWNTs across gaps between electrodes that would serve, subsequently, as source and drain contacts during operation of the transistors. In preparation for the experiment, a multilayer catalyst comprising a 20-nmthick underlayer of iridium (platinum group), a 1-nm-thick middle layer of iron, and a 0.2-nm-thick outer layer of molybdenum was ion-beam sputtered onto a quartz substrate. A 25 micrometers-diameter iron wire was used as a shadow mask during the sputtering to create a 25 micrometers gap in the catalyst. Then electrical leads were connected to the catalyst areas separated by the gap so that these catalyst areas would also serve as electrodes. The substrate as thus prepared was placed in a growth chamber that consisted of a quartz tube of 1-in. (2.54-cm) diameter enclosed in a furnace. SWNTs of acceptably high quantity and quality were grown in 10 minutes with methane at atmospheric pressure flowing through the chamber at a rate of 1,000 standard cubic centimeters per minute at a temperature of 900 C. To prevent oxidation of the SWNTs, the chamber was purged with 99.999-percent pure argon before and after growth, and the chamber was cooled to less than 300 C before opening it to the atmosphere after growth. When no voltage was applied across the gap, the SWNTs grew in random directions extending out from the edges of the catalyst at the gap. When a potential of 10 V was applied between the catalyst/electrode areas to create an electric field across the gap, the SWNTs grew across the gap, as shown in the figure.

MEMS-based thin-film fuel cells

DOEpatents

Jankowksi, Alan F.; Morse, Jeffrey D.

2003-10-28

A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

Esterification of fermentation-derived acids via pervaporation

DOEpatents

Datta, R.; Tsai, S.P.

1998-03-03

A low temperature method for esterifying ammonium- and amine-containing salts is provided whereby the salt is reacted with an alcohol in the presence of heat and a catalyst and then subjected to a dehydration and deamination process using pervaporation. The invention also provides for a method for producing esters of fermentation derived, organic acid salt comprising first cleaving the salt into its cationic part and anionic part, mixing the anionic part with an alcohol to create a mixture; heating the mixture in the presence of a catalyst to create an ester; dehydrating the now heated mixture; and separating the ester from the now-dehydrated mixture. 2 figs.

Esterification of fermentation-derived acids via pervaporation

DOEpatents

Datta, Rathin; Tsai, Shih-Perng

1998-01-01

A low temperature method for esterifying ammonium- and amine-containing salts is provided whereby the salt is reacted with an alcohol in the presence of heat and a catalyst and then subjected to a dehydration and deamination process using pervaporation. The invention also provides for a method for producing esters of fermentation derived, organic acid salt comprising first cleaving the salt into its cationic part and anionic part, mixing the anionic part with an alcohol to create a mixture; heating the mixture in the presence of a catalyst to create an ester; dehydrating the now heated mixture; and separating the ester from the now-dehydrated mixture.

Long life hydrocarbon conversion catalyst and method of making

DOEpatents

Tonkovich, Anna Lee Y [Pasco, WA; Wang, Yong [Richland, WA; Gao, Yufei [Kennewick, WA

2002-11-12

The present invention includes a catalyst that has at least four layers, (1) porous support, (2) buffer layer, (3) interfacial layer, and optionally (4) catalyst layer. The buffer layer provides a transition of thermal expansion coefficient from the porous support to the interfacial layer thereby reducing thermal expansion stress as the catalyst is heated to high operating temperatures. The method of the present invention for making the at least three layer catalyst has the steps of (1) selecting a porous support, (2) solution depositing an interfacial layer thereon, and optionally (3) depositing a catalyst material onto the interfacial layer; wherein the improvement comprises (4) depositing a buffer layer between the porous support and the interfacial layer.

Selective catalysts and their preparation for catalytic hydrocarbon synthesis

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

Iglesia, E.; Vroman, H.; Soled, S.

1991-07-30

This patent describes a method for preparing a supported cobalt catalyst particle. It comprises contacting a support particle with a molten cobalt salt, for a period sufficient to impregnate substantially all of the molten cobalt salt on the support to a depth of less than about 200 {mu}m; drying the supported cobalt salt obtained; reducing the cobalt of the supported cobalt salt to metallic cobalt by heating the salt in the presence of H{sub 2}, wherein the heating is conducted at a rate of less than about 1{degrees} C./min. up to a maximum temperature ranging from about 100{degrees} C. tomore » about 500{degrees} C., to produce a supported cobalt catalyst particle.« less

Hydrodeoxygenation of Pyrolysis Bio-Oil Over Ni Impregnated Mesoporous Materials.

PubMed

Lee, In-Gu; Lee, Heejin; Kang, Bo Sung; Kim, Young-Min; Kim, Sang Chai; Jung, Sang-Chul; Ko, Chang Hyun; Park, Young-Kwon

2018-02-01

The catalytic hydrodeoxygenation (HDO) of bio-oil over Ni-supported mesoporous materials was performed using a high pressure autoclave reactor. The actual pyrolysis oil of cork oak wood was used as a sample, and Ni/Al-SBA-15 and Ni/Al-MSU-F were used as catalysts. In addition, supercritical ethanol was added as solvent. Both Ni-supported mesoporous catalysts showed efficient HDO reaction ability. A higher heating value and pH of bio-oil were achieved by the HDO reaction over both catalysts and upgraded bio-oil had a lower viscosity. Compared to Ni/Al-MSU-F, Ni/Al- SBA-15 produced more upgraded bio-oil with a lower oxygen content and higher heating value via a catalytic HDO process.

Solid oxide fuel cells having porous cathodes infiltrated with oxygen-reducing catalysts

DOEpatents

Liu, Meilin; Liu, Ze; Liu, Mingfei; Nie, Lifang; Mebane, David Spencer; Wilson, Lane Curtis; Surdoval, Wayne

2014-08-12

Solid-oxide fuel cells include an electrolyte and an anode electrically coupled to a first surface of the electrolyte. A cathode is provided, which is electrically coupled to a second surface of the electrolyte. The cathode includes a porous backbone having a porosity in a range from about 20% to about 70%. The porous backbone contains a mixed ionic-electronic conductor (MIEC) of a first material infiltrated with an oxygen-reducing catalyst of a second material different from the first material.

SULFUR TOLERANT CATALYSTS FOR BIOMASS TAR REMOVAL - PHASE I

EPA Science Inventory

In this Small Business Innovation Research (SBIR) project, NexTech Materials proposes a catalytic reforming approach to remove waste tar from gasified biomass on nickel-based catalysts. Biomass gasification is a potential renewable route to producing electricity, liquid fue...

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

Sanders, R.S.

The effects of heat strip time, heat strip temperature, catalyst ratio, mold cure time, post cure time, and post cure temperature on a hybrid (UCC/SE-54/497XL) cellular silicone molding compound are reported.

Improved Anode for a Direct Methanol Fuel Cell

NASA Technical Reports Server (NTRS)

Valdez, Thomas; Narayanan, Sekharipuram

2005-01-01

A modified chemical composition has been devised to improve the performance of the anode of a direct methanol fuel cell. The main feature of the modified composition is the incorporation of hydrous ruthenium oxide into the anode structure. This modification can reduce the internal electrical resistance of the cell and increase the degree of utilization of the anode catalyst. As a result, a higher anode current density can be sustained with a smaller amount of anode catalyst. These improvements can translate into a smaller fuel-cell system and higher efficiency of conversion. Some background information is helpful for understanding the benefit afforded by the addition of hydrous ruthenium oxide. The anode of a direct methanol fuel cell sustains the electro-oxidation of methanol to carbon dioxide in the reaction CH3OH + H2O--->CO2 + 6H(+) + 6e(-). An electrocatalyst is needed to enable this reaction to occur. The catalyst that offers the highest activity is an alloy of approximately equal numbers of atoms of the noble metals platinum and ruthenium. The anode is made of a composite material that includes high-surface-area Pt/Ru alloy particles and a proton-conducting ionomeric material. This composite is usually deposited onto a polymer-electrolyte (proton-conducting) membrane and onto an anode gas-diffusion/current-collector sheet that is subsequently bonded to the proton-conducting membrane by hot pressing. Heretofore, the areal density of noble-metal catalyst typically needed for high performance has been about 8 mg/cm2. However, not all of the catalyst has been utilized in the catalyzed electro-oxidation reaction. Increasing the degree of utilization of the catalyst would make it possible to improve the performance of the cell for a given catalyst loading and/or reduce the catalyst loading (thereby reducing the cost of the cell). The use of carbon and possibly other electronic conductors in the catalyst layer has been proposed for increasing the utilization of the catalyst by increasing electrical connectivity between catalyst particles. However, the relatively low density of carbon results in thick catalyst layers that impede the mass transport of methanol to the catalytic sites. Also, the electrical conductivity of carbon is less than 1/300th of typical metals. Furthermore, the polymer-electrolyte membrane material is acidic and most metals are not chemically stable in contact with it. Finally, a material that conducts electrons (but not protons) does not contribute to the needed transport of protons produced in the electro-oxidation reaction.

The shape conversion of silver nanoparticles through heating and its application as homogeneous catalyst in reduction of 4- nitrophenol

NASA Astrophysics Data System (ADS)

Ariyanta, H. A.; Yulizar, Y.

2016-02-01

The shape conversion of silver nanoparticles (AgNPs) through heating and its application as a homogeneous catalyst in the reduction of 4-nitrophenol is reported here. Synthesis of AgNPs by reduction of AgNO3 using NaBH4 and sodium citrate as reducing agent were successfully conducted. The addition of PVP was used as stabilizing agent. The synthesized AgNPs were heated at 95 °C and observed using UV-Vis spectrophotometer, transmission electron microscopy (TEM), Fourier-transformed infrared (FTIR) spectroscopy and particle size analyzer (PSA). Characteristics of AgNPs before heated were blue with UV- Vis absorbance spectrum at λmax = 786 nm and the shape was pseudo nano prism sized ± 28 nm. During the heating process, the color changed gradually from blue (λmax = 786 nm) to orange (λmax = 486 nm) and also its shape from nano prism to nanodisk. Silver nano prism has a lattice constant, 4.160 Å, larger than the silver nanodisk, 4.081 Å, which was possibly achieved through rearrangement of silver atoms on the surface of AgNPs. Both silver nanodisk and nano prism were tested as a homogeneous catalyst for the reduction of 4-nitrophenol (4- NP) with NaBH4.

Investigation of Methods of Inspired Gas Heating.

DTIC Science & Technology

1981-10-30

inhaled gas. Good for one hour at 1 percent CO, the apparatus is a simple Hopcalite catalyst bed mounted on a mouthpiece. Hopcalite , a mixture of...Respirator pro- The Self-Rescuer uses the oxidation also expeiled through the expiratory vides emergency respiratory protection catalyst Hopcalites to...tection against carbon monoxide in the Hopcalite catalyst, and a drying life; it can be carried by personnel or otherwise respirable air; it should not

Catalysts for use in electrochemical applications and electrodes and devices using same

DOEpatents

Ozkan, Umit S.; von Deak, Dieter; Biddinger, Elizabeth

2015-09-15

An electrode for reduction of an oxidant including a phosphorus-doped carbon-containing catalyst represented by the chemical formula CN.sub.xP.sub.y, where x is from 0 to about 10 wt. % and y is from about 1 ppm to about 10 wt. %. A device for producing electricity by facilitating an electrochemical reaction between a fuel and an oxidant. The device including a first electrode for oxidizing the fuel to produce protons and electrons. The device further includes a second electrode in electrical communication with the first electrode when electrically connected to the external circuit. The second electrode includes a phosphorus-doped carbon-containing catalyst for reducing the oxidant and is represented by the chemical formula CN.sub.xP.sub.y, where x is from 0 to about 10 wt. % and y is from about 1 ppm to about 10 wt. %. The device further includes an electrolyte, such as, a membrane, separating the first electrode from the second electrode.

High-performance liquid-catalyst fuel cell for direct biomass-into-electricity conversion.

PubMed

Liu, Wei; Mu, Wei; Deng, Yulin

2014-12-01

Herein, we report high-performance fuel cells that are catalyzed solely by polyoxometalate (POM) solution without any solid metal or metal oxide. The novel design of the liquid-catalyst fuel cells (LCFC) changes the traditional gas-solid-surface heterogeneous reactions to liquid-catalysis reactions. With this design, raw biomasses, such as cellulose, starch, and even grass or wood powders can be directly converted into electricity. The power densities of the fuel cell with switchgrass (dry powder) and bush allamanda (freshly collected) are 44 mW cm(-2) and 51 mW cm(-2) respectively. For the cellulose-based biomass fuel cell, the power density is almost 3000 times higher than that of cellulose-based microbial fuel cells. Unlike noble-metal catalysts, POMs are tolerant to most organic and inorganic contaminants. Therefore, almost any raw biomass can be used directly to produce electricity without prior purification. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Release of hydrogen sulfide during microwave pyrolysis of sewage sludge: Effect of operating parameters and mechanism.

PubMed

Zhang, Jun; Zuo, Wei; Tian, Yu; Yin, Linlin; Gong, Zhenlong; Zhang, Jie

2017-06-05

The effects of sludge characteristics, pyrolysis temperature, heating rate and catalysts on the release of H 2 S and mechanism of H 2 S formation during sludge pyrolysis were investigated in a microwave heating reactor (MHR). The evolution of sulfur-containing compounds in the pyrolysis chars obtained at temperature range of 400-800°C was characterized by XPS. For a given temperature, the maximum concentration of H 2 S appeared at moisture content of 80%. Compared to the influence of heating rate on the H 2 S yields, pyrolysis temperature and catalyst played a more significant role on the release of H 2 S during microwave pyrolysis process. The H 2 S concentration increased with increasing temperature from 400°C to 800°C while decreased with increasing heating rate. Both the Nickel-based catalyst and Dolomite displayed significant desulfurization effect and Ni-based catalyst exhibited the larger desulfurization capability than that of Dolomite. The organic sulfur compounds accounted for about 60% of the total sulfur in the sludge which was the main reason for the formation of H 2 S. The mechanism analysis indicated that the cleavage reactions of mercaptan and aromatic-S compounds at temperatures below 600°C and the cracking reaction of sulfate above 700°C respectively were responsible for the H 2 S release during sludge pyrolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Apparatuses and methods for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Kalnes, Tom N.

2015-12-29

Apparatuses and methods for deoxygenating a biomass-derived pyrolysis oil are provided herein. In one example, the method comprises of dividing a feedstock stream into first and second feedstock portions. The feedstock stream comprises the biomass-derived pyrolysis oil and has a temperature of about 60.degree. C. or less. The first feedstock portion is combined with a heated organic liquid stream to form a first heated diluted pyoil feed stream. The first heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen to form an intermediate low-oxygen pyoil effluent. The second feedstock portion is combined with the intermediate low-oxygen pyoil effluent to form a second heated diluted pyoil feed stream. The second heated diluted pyoil feed stream is contacted with a second deoxygenating catalyst in the presence of hydrogen to form additional low-oxygen pyoil effluent.

Dipole-Oriented Molecular Solids Can Undergo a Phase Change and Still Maintain Electrical Polarization

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

Cassidy, Andrew; Jørgensen, Mads R. V.; Rosu-Finsen, Alexander

2016-10-02

It has recently been demonstrated that nanoscale molecular films can spontaneously assemble to self-generate intrinsic electric fields that can exceed 10 8 V/m. These electric fields originate from polarization charges in the material that arise because the films self-assemble to orient molecular dipole moments. This has been called the spontelectric effect. Such growth of spontaneously polarized layers of molecular solids has implications for our understanding of how intermolecular interactions dictate the structure of molecular materials used in a range of applications, for example, molecular semiconductors, sensors, and catalysts. In this paper, we present the first in situ structural characterization ofmore » a representative spontelectric solid, nitrous oxide. Infrared spectroscopy, temperature-programmed desorption, and neutron reflectivity measurements demonstrate that polarized films of nitrous oxide undergo a structural phase transformation upon heating above 48 K. A mean-field model can be used to describe quantitatively the magnitude of the spontaneously generated field as a function of film-growth temperature, and this model also recreates the phase change. Finally, this reinforces the spontelectric model as a means of describing long-range dipole–dipole interactions and points to a new type of ordering in molecular thin films.« less

Alloy catalysts for fuel cell-based alcohol sensors

NASA Astrophysics Data System (ADS)

Ghavidel, Mohammadreza Zamanzad

Direct ethanol fuel cells (DEFCs) are attractive from both economic and environmental standpoints for generating renewable energy and powering vehicles and portable electronic devices. There is a great interest recently in developing DEFC systems. The cost and performance of the DEFCs are mainly controlled by the Pt-base catalysts used at each electrode. In addition to energy conversion, DEFC technology is commonly employed in the fuel-cell based breath alcohol sensors (BrAS). BrAS is a device commonly used to measure blood alcohol concentration (BAC) and enforce drinking and driving laws. The BrAS is non-invasive and has a fast respond time. However, one of the most important drawback of the commercially available BrAS is the very high loading of Pt employed. One well-known and cost effective method to reduce the Pt loading is developing Pt-alloy catalysts. Recent studies have shown that Pt-transition metal alloy catalysts enhanced the electroactivity while decreasing the required loadings of the Pt catalysts. In this thesis, carbon supported Pt-Mn and Pt-Cu electrocatalysts were synthesized by different methods and the effects of heat treatment and structural modification on the ethanol oxidation reaction (EOR) activity, oxygen reduction reaction (ORR) activity and durability of these samples were thoroughly studied. Finally, the selected Pt-Mn and Pt-Cu samples with the highest EOR activity were examined in a prototype BrAS system and compared to the Pt/C and Pt 3Sn/C commercial electrocatalysts. Studies on the Pt-Mn catalysts produced with and without additives indicate that adding trisodium citrate (SC) to the impregnation solution improved the particle dispersion, decreased particle sizes and reduced the time required for heat treatment. Further studies show that the optimum weight ratio of SC to the metal loading in the impregnation solution was 2:1 and optimum results achieved at pH lower than 4. In addition, powder X-ray diffraction (XRD) analyses indicate that the optimum heat treatment temperature was 700 °C where a uniform ordered PtMn intermetallic phase was formed. Although the electrochemical active surface area (ECSA) decreased due to the heat treatment, the EOR activity of Pt-Mn samples was improved. Moreover, it was shown that the heat-treated samples prepared in the presence of SC showed superior the EOR activity compared to the samples made without SC. The Pt-Cu/C alloys were produced by three different methods: impregnation, impregnation in the presence of sodium citrate and microwave assisted polyol methods. These studies showed that the polyol method was the optimum method to produce the Pt-Cu alloy. The XRD analysis indicates that the heat treatment at 700 °C developed catalysts rich in the PtCu and PtCu3 ordered phases. The highest EOR activity was measured for the Pt-Cu/C-POL (sample made by the polyol method) and heat treated at 700 °C for 1h. Comparing the EOR activity of the Pt-Cu and Pt-Mn samples also demonstrates that the heat treated Pt-Cu/C-POL sample showed higher EOR activity compared to the Pt-Mn samples. These results indicate that the benefits of thermally treating alloy nanoparticles could outweigh any activity losses that may occur due to the particle size growth and the ECSA loss. Besides, accelerated stress tests (ASTs) illustrate that the heat treatment improved the durability of the Pt-Mn and Pt-Cu samples. The durability and EOR activity of the heat treated Pt-Mn and Pt-Cu samples was similar or better than commercial samples. On the other hand, the ORR activity of Pt-Mn and Pt-Cu after the heat treatment was slightly lower than the commercial samples but the ORR activity loss can be compensated by the economic benefits from using the lower Pt loading. Finally, studying the alcohol sensing characteristic of different samples shows that the heat treated Pt-Mn and Pt-Cu catalysts could be used for the ethanol sensing. Additionally, among the different commercial samples tested for ethanol sensing, Pt-Sn/C showed the highest sensitivity but with slightly higher standard deviation. Further studies on the Pt- Cu/C and Pt-Mn/C samples indicate that the heat treatment improved the sensitivity of these samples and the highest normalized sensitivity among all the samples belonged to the Pt- Cu/C-POL (sample produced by polyol method) and heat treated at 700 °C. It can be concluded that the heat treated Pt-Mn and Pt-Cu samples could be used as an alternative to replace Pt black in commercial sensors which would dramatically decrease the Pt loading. This could reduce the price and increase the sensitivity of commercial alcohol sensors.

Nano-Structured Bio-Inorganic Hybrid Material for High Performing Oxygen Reduction Catalyst.

PubMed

Jiang, Rongzhong; Tran, Dat T; McClure, Joshua P; Chu, Deryn

2015-08-26

In this study, we demonstrate a non-Pt nanostructured bioinorganic hybrid (BIH) catalyst for catalytic oxygen reduction in alkaline media. This catalyst was synthesized through biomaterial hemin, nanostructured Ag-Co alloy, and graphene nano platelets (GNP) by heat-treatment and ultrasonically processing. This hybrid catalyst has the advantages of the combined features of these bio and inorganic materials. A 10-fold improvement in catalytic activity (at 0.8 V vs RHE) is achieved in comparison of pure Ag nanoparticles (20-40 nm). The hybrid catalyst reaches 80% activity (at 0.8 V vs RHE) of the state-of-the-art catalyst (containing 40% Pt and 60% active carbon). Comparable catalytic stability for the hybrid catalyst with the Pt catalyst is observed by chronoamperometric experiment. The hybrid catalyst catalyzes 4-electron oxygen reduction to produce water with fast kinetic rate. The rate constant obtained from the hybrid catalyst (at 0.6 V vs RHE) is 4 times higher than that of pure Ag/GNP catalyst. A catalytic model is proposed to explain the oxygen reduction reaction at the BIH catalyst.

Low pressure catalytic co-conversion of biogenic waste (rapeseed cake) and vegetable oil.

PubMed

Giannakopoulou, Kanellina; Lukas, Michael; Vasiliev, Aleksey; Brunner, Christoph; Schnitzer, Hans

2010-05-01

Zeolite catalysts of three types (H-ZSM-5, Fe-ZSM-5 and H-Beta) were tested in the catalytic co-conversion of rapeseed cake and safflower oil into bio-fuel. This low pressure process was carried out at the temperatures of 350 and 400 degrees Celsius. The yields and compositions of the product mixtures depended on the catalyst nature and the process temperatures. The produced organic phases consisted mainly of hydrocarbons, fatty acids and nitriles. This mixture possessed improved characteristics (e.g. heating value, water content, density, viscosity, pH) compared with the bio-oils, making possible its application as a bio-fuel. The most effective catalyst, providing the highest yield of organic liquid phase, was the highly acidic/wide-pore H-Beta zeolite. The products obtained on this catalyst demonstrated the highest degree of deoxygenation and the higher HHV (Higher Heating Value). The aqueous liquid phase contained water-soluble carboxylic acids, phenols and heterocyclic compounds. Copyright 2009 Elsevier Ltd. All rights reserved.

Catalysts for the hydrodenitrogenation of organic materials and process for the preparation of the catalysts

DOEpatents

Laine, R.M.; Hirschon, A.S.; Wilson, R.B. Jr.

1987-12-29

A process is described for the preparation of a multimetallic catalyst for the hydrodenitrogenation of an organic feedstock, which process comprises: (a) forming a precatalyst itself comprising: (1) a first metal compound selected from compounds of nickel, cobalt or mixtures thereof; (2) a second metal compound selected from compounds of chromium, molybdenum, tungsten, or mixtures thereof; and (3) an inorganic support; (b) heating the precatalyst of step (a) with a source of sulfide in a first non-oxidizing gas at a temperature and for a time effective to presulfide the precatalyst; (c) adding in a second non-oxidizing gas to the sulfided precatalyst of step (b) an organometallic transition metal moiety selected from compounds of iridium, rhodium, iron, ruthenium, tungsten or mixtures thereof for a time and at a temperature effective to chemically combine the metal components; and (d) optionally heating the chemically combined catalyst of step (b) in vacuum at a temperature and for a time effective to remove residual volatile organic materials. 12 figs.

Thermal degradation of Shredded Oil Palm Empty Fruit Bunches (SOPEFB) embedded with Cobalt catalyst by Thermogravimetric Analysis (TGA)

NASA Astrophysics Data System (ADS)

Alias, R.; Hamid, N. H.; Jaapar, J.; Musa, M.; Alwi, H.; Halim, K. H. Ku

2018-03-01

Thermal behavior and decomposition kinetics of shredded oil palm empty fruit bunches (SOPEFB) were investigated in this study by using thermogravimetric analysis (TGA). The SOPEFB were analyzed under conditions of temperature 30 °C to 900 °C with nitrogen gas flow at 50 ml/min. The SOPEFB were embedded with cobalt (II) nitrate solution with concentration 5%, 10%, 15% and 20%. The TG/DTG curves shows the degradation behavior of SOPEFB following with char production for each heating rate and each concentration of cobalt catalyst. Thermal degradation occurred in three phases, water drying phase, decomposition of hemicellulose and cellulose phase, and lignin decomposition phase. The kinetic equation with relevant parameters described the activation energy required for thermal degradation at the temperature regions of 200 °C to 350 °C. Activation energy (E) for different heating rate with SOPEFB embedded with different concentration of cobalt catalyst showing that the lowest E required was at SOPEFB with 20% concentration of cobalt catalyst..

Application of a mixed metal oxide catalyst to a metallic substrate

NASA Technical Reports Server (NTRS)

Sevener, Kathleen M. (Inventor); Lohner, Kevin A. (Inventor); Mays, Jeffrey A. (Inventor); Wisner, Daniel L. (Inventor)

2009-01-01

A method for applying a mixed metal oxide catalyst to a metallic substrate for the creation of a robust, high temperature catalyst system for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in propulsion systems. The method begins by forming a prepared substrate material consisting of a metallic inner substrate and a bound layer of a noble metal intermediate. Alternatively, a bound ceramic coating, or frit, may be introduced between the metallic inner substrate and noble metal intermediate when the metallic substrate is oxidation resistant. A high-activity catalyst slurry is applied to the surface of the prepared substrate and dried to remove the organic solvent. The catalyst layer is then heat treated to bind the catalyst layer to the surface. The bound catalyst layer is then activated using an activation treatment and calcinations to form the high-activity catalyst system.

Carbon nanotube nanoelectrode arrays

DOEpatents

Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

2008-11-18

The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers: Innovative Clean Coal Technology (ICCT). Quarterly report No. 7, January--March 1992

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

Not Available

1992-05-01

The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the amonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japanmore » and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO, and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal. The demonstration will be performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project will be funded by the US Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), and the Electric Power Research Institute.« less

Automated protein hydrolysis delivering sample to a solid acid catalyst for amino acid analysis.

PubMed

Masuda, Akiko; Dohmae, Naoshi

2010-11-01

In this study, we developed an automatic protein hydrolysis system using strong cation-exchange resins as solid acid catalysts. Examining several kinds of inorganic solid acids and cation-exchange resins, we found that a few cation-exchange resins worked as acid catalysts for protein hydrolysis when heated in the presence of water. The most efficient resin yielded amounts of amino acids that were over 70% of those recovered after conventional hydrolysis with hydrochloric acid and resulted in amino acid compositions matching the theoretical values. The solid-acid hydrolysis was automated by packing the resin into columns, combining the columns with a high-performance liquid chromatography system, and heating them. The amino acids that constitute a protein can thereby be determined, minimizing contamination from the environment.

Microwave assisted alkali-catalyzed transesterification of Pongamia pinnata seed oil for biodiesel production.

PubMed

Kumar, Ritesh; Kumar, G Ravi; Chandrashekar, N

2011-06-01

In this study, microwave assisted transesterification of Pongamia pinnata seed oil was carried out for the production of biodiesel. The experiments were carried out using methanol and two alkali catalysts i.e., sodium hydroxide (NaOH) and potassium hydroxide (KOH). The experiments were carried out at 6:1 alcohol/oil molar ratio and 60°C reaction temperature. The effect of catalyst concentration and reaction time on the yield and quality of biodiesel was studied. The result of the study suggested that 0.5% sodium hydroxide and 1.0% potassium hydroxide catalyst concentration were optimum for biodiesel production from P. pinnata oil under microwave heating. There was a significant reduction in reaction time for microwave induced transesterification as compared to conventional heating. Copyright © 2011 Elsevier Ltd. All rights reserved.

The selective hydrogenation of crotonaldehyde over bimetallic catalysts

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

Schoeb, Ann M.

1997-10-17

The selective hydrogenation of crotonaldehyde has been investigated over a monometallic Pt/SiO 2 catalyst and platinum bimetallic catalysts where the second metal was either silver, copper, or tin. The effects of addition of a second metal to the Pt/SiO 2 system on the selectivity to crotyl alcohol were investigated. The Pt-Sn bimetallic catalysts were characterized by hydrogen chemisorption, 1H NMR and microcalorimetry. The Pt-Ag/SiO 2 and Pt-Cu/SiO 2 catalysts were characterized by hydrogen chemisorption. Pt-Sn/SiO 2 catalysts selectively hydrogenated crotonaldehyde to crotyl alcohol and the method of preparation of these catalysts affected the selectivity. The most selective Pt-Sn/SiO 2 catalystsmore » for the hydrogenation of crotonaldehyde to crotyl alcohol were those in which the Sn precursor was dissolved in a HCl solution. Sn increased both the rate of formation of butyraldehyde and the rate of formation of crotyl alcohol. The Pt/SiO 2, Pt-Ag/SiO 2 and Pt-Cu/SiO 2 catalysts produced only butyraldehyde. Initial heats of adsorption (~90 kJ/mol) measured using microcalorimetry were not affected by the presence of Sn on Pt. We can conclude that there is no through metal electronic interaction between Pt and Sn at least with respect to hydrogen surface bonds since the Pt and Pt-Sn at least with respect to hydrogen surface bonds since the Pt and Pt-Sn had similar initial heats of adsorption coupled with the invariance of the 1H NMR Knight shift.« less

Catalytic ignitor for regenerative propellant gun

NASA Technical Reports Server (NTRS)

Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

1994-01-01

An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the ignitor and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

Catalytic Ignitor for Regenerative Propellant Gun

NASA Technical Reports Server (NTRS)

Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)

1997-01-01

An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the igniter and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.

Ionic Liquid as a Solvent and Catalyst for Acylation of Maltodextrin

USDA-ARS?s Scientific Manuscript database

Catalyst-free esterification of maltodextrin was carried out in ionic liquid. Stearate esters of maltodextrin were obtained in various degree of substitution (DS) when vinyl stearate or stearic acid was heated with maltodextrin in ionic liquid, 1-butyl-3-methylimidazolium cyanamide (bmim[dca]). Re...

An experimental study of catalytic and non-catalytic reaction in heat recirculating reactors and applications to power generation

NASA Astrophysics Data System (ADS)

Ahn, Jeongmin

An experimental study of the performance of a Swiss roll heat exchanger and reactor was conducted, with emphasis on the extinction limits and comparison of results with and without Pt catalyst. At Re<40, the catalyst was required to sustain reaction; with the catalyst self-sustaining reaction could be obtained at Re less than 1. Both lean and rich extinction limits were extended with the catalyst, though rich limits were extended much further. At low Re, the lean extinction limit was rich of stoichiometric and rich limit had equivalence ratios 80 in some cases. Non-catalytic reaction generally occurred in a flameless mode near the center of the reactor. With or without catalyst, for sufficiently robust conditions, a visible flame would propagate out of the center, but this flame could only be re-centered with catalyst. Gas chromatography indicated that at low Re, CO and non-C3 H8 hydrocarbons did not form. For higher Re, catalytic limits were slightly broader but had much lower limit temperatures. At sufficiently high Re, catalytic and gas-phase limits merged. Experiments with titanium Swiss rolls have demonstrated reducing wall thermal conductivity and thickness leads to lower heat losses and therefore increases operating temperatures and extends flammability limits. By use of Pt catalysts, reaction of propane-air mixtures at temperatures 54°C was sustained. Such low temperatures suggest that polymers may be employed as a reactor material. A polyimide reactor was built and survived prolonged testing at temperatures up to 500°C. Polymer reactors may prove more practical for microscale devices due to their lower thermal conductivity and ease of manufacturing. Since the ultimate goal of current efforts is to develop combustion driven power generation devices at MEMS like scales, a thermally self-sustaining miniature power generation device was developed utilizing a single-chamber solid-oxide-fuel-cell (SOFC) placed in a Swiss roll. With the single-chamber design, fuel/oxygen crossover due to cracking of seals via thermal cycling is irrelevant and coking on the anode is practically eliminated. SOFC power densities up to 420mW/cm2 were observed at low Re. These results suggest that single-chamber SOFC's integrated with heat-recirculating reactors may be a viable approach for small-scale power generation devices.

Fabrication of fuel cell electrodes and other catalytic structures

DOEpatents

Smith, J.L.

1987-02-11

A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte. 1 fig.

Fabrication of catalytic electrodes for molten carbonate fuel cells

DOEpatents

Smith, James L.

1988-01-01

A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte.

Pyrolysis of poly(vinyl chloride) and-electric arc furnacedust mixtures.

PubMed

Al-Harahsheh, Mohammad; Al-Otoom, Awni; Al-Makhadmah, Leema; Hamilton, Ian E; Kingman, Sam; Al-Asheh, Sameer; Hararah, Muhanned

2015-12-15

An investigation into the pyrolysis kinetics of PVC mixed with electric arc furnace dust (EAFD) was performed. Mixtures of both materials with varying PVC ratios (1:1, 1:2, 1:3) were prepared and pyrolyzed in a nitrogen atmosphere under dynamic heating conditions at different heating rates (5, 10, 30 and 50 °C/min). The pyrolysis process proceeded through two main decomposition steps; the first step involved the release of HCl which reacted with the metal oxides present in the dust, subsequently forming metal chlorides and water vapor. Benzene was also found to release as detected by TGA-MS. The remaining hydrocarbons in the polymer backbone decomposed further in the second step releasing further volatile hydrocarbons. Different models were used to fit the kinetic data namely the integral, the Van Krevelen, and Coats and Red fern methods. The presence of EAFD during PVC decomposition resulted in a considerable decrease in the activation energy of the reaction occurring during the first decomposition region. Furthermore, iron oxides were retained in the pyrolysis residue, whilst other valuable metals, including Zn and Pb, were converted to chlorides that are recoverable by leaching in water. It is believed that EAFD can be utilized as an active catalyst to produce energy gases such as propyneas evident from the TGA-MS. Copyright © 2015 Elsevier B.V. All rights reserved.

Oxygen sensor for monitoring gas mixtures containing hydrocarbons

DOEpatents

Ruka, Roswell J.; Basel, Richard A.

1996-01-01

A gas sensor measures O.sub.2 content of a reformable monitored gas containing hydrocarbons H.sub.2 O and/or CO.sub.2, preferably in association with an electrochemical power generation system. The gas sensor has a housing communicating with the monitored gas environment and carries the monitored gas through an integral catalytic hydrocarbon reforming chamber containing a reforming catalyst, and over a solid electrolyte electrochemical cell used for sensing purposes. The electrochemical cell includes a solid electrolyte between a sensor electrode that is exposed to the monitored gas, and a reference electrode that is isolated in the housing from the monitored gas and is exposed to a reference gas environment. A heating element is also provided in heat transfer communication with the gas sensor. A circuit that can include controls operable to adjust operations via valves or the like is connected between the sensor electrode and the reference electrode to process the electrical signal developed by the electrochemical cell. The electrical signal varies as a measure of the equilibrium oxygen partial pressure of the monitored gas. Signal noise is effectively reduced by maintaining a constant temperature in the area of the electrochemical cell and providing a monitored gas at chemical equilibria when contacting the electrochemical cell. The output gas from the electrochemical cell of the sensor is fed back into the conduits of the power generating system.

Oxygen sensor for monitoring gas mixtures containing hydrocarbons

DOEpatents

Ruka, R.J.; Basel, R.A.

1996-03-12

A gas sensor measures O{sub 2} content of a reformable monitored gas containing hydrocarbons, H{sub 2}O and/or CO{sub 2}, preferably in association with an electrochemical power generation system. The gas sensor has a housing communicating with the monitored gas environment and carries the monitored gas through an integral catalytic hydrocarbon reforming chamber containing a reforming catalyst, and over a solid electrolyte electrochemical cell used for sensing purposes. The electrochemical cell includes a solid electrolyte between a sensor electrode that is exposed to the monitored gas, and a reference electrode that is isolated in the housing from the monitored gas and is exposed to a reference gas environment. A heating element is also provided in heat transfer communication with the gas sensor. A circuit that can include controls operable to adjust operations via valves or the like is connected between the sensor electrode and the reference electrode to process the electrical signal developed by the electrochemical cell. The electrical signal varies as a measure of the equilibrium oxygen partial pressure of the monitored gas. Signal noise is effectively reduced by maintaining a constant temperature in the area of the electrochemical cell and providing a monitored gas at chemical equilibria when contacting the electrochemical cell. The output gas from the electrochemical cell of the sensor is fed back into the conduits of the power generating system. 4 figs.

Hot wire needle probe for thermal conductivity detection

DOEpatents

Condie, Keith Glenn; Rempe, Joy Lynn; Knudson, Darrell lee; Daw, Joshua Earl; Wilkins, Steven Curtis; Fox, Brandon S.; Heng, Ban

2015-11-10

An apparatus comprising a needle probe comprising a sheath, a heating element, a temperature sensor, and electrical insulation that allows thermal conductivity to be measured in extreme environments, such as in high-temperature irradiation testing. The heating element is contained within the sheath and is electrically conductive. In an embodiment, the heating element is a wire capable of being joule heated when an electrical current is applied. The temperature sensor is contained within the sheath, electrically insulated from the heating element and the sheath. The electrical insulation electrically insulates the sheath, heating element and temperature sensor. The electrical insulation fills the sheath having electrical resistance capable of preventing electrical conduction between the sheath, heating element, and temperature sensor. The control system is connected to the heating element and the temperature sensor.

Thermally stable single-atom platinum-on-ceria catalysts via atom trapping

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

Jones, John; Xiong, Haifeng; DelaRiva, Andrew

2016-07-08

Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/ aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoringmore » the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst.« less

New Pt/Alumina model catalysts for STM and in situ XPS studies

NASA Astrophysics Data System (ADS)

Nartova, Anna V.; Gharachorlou, Amir; Bukhtiyarov, Andrey V.; Kvon, Ren I.; Bukhtiyarov, Valerii I.

2017-04-01

The new Pt/alumina model catalysts for STM and in situ XPS studies based on thin alumina film formed over the conductive substrate are proposed. Procedure of platinum deposition developed for porous alumina was adapted for the model alumina support. The set of Pt/AlOx-film samples with the different mean platinum particle size was prepared. Capabilities of in situ XPS investigations of the proposed catalysts were demonstrated in study of NO decomposition on platinum nanoparticles. It is shown that proposed model catalysts behave similarly to Pt/γ-Al2O3 and provide the new opportunities for the instrumental studies of platinum catalysts due to resolving several issues (charging, heating, screening) that are typical for the investigation of the porous oxide supported catalysts.

Stability of High-Performance Pt-Based Catalysts for Oxygen Reduction Reactions.

PubMed

Lin, Rui; Cai, Xin; Zeng, Hao; Yu, Zhuoping

2018-04-01

Due to their environmental sustainability and high efficiency, proton-exchange-membrane fuel cells (PEMFCs) are expected to be an essential type of energy source for electric vehicles, energy generation, and the space industry in the coming decades. Here, the recent developments regarding shape-controlled nanostructure catalysts are reviewed, with a focus on the stability of high-performance Pt-based catalysts and related mechanisms. The catalysts, which possess great activity, are still far from meeting the requirements of their applications, due to stability issues, especially in membrane electrode assemblies (MEAs). Thus, solutions toward the comprehensive performance of Pt-based catalysts are discussed here. The research trends and related theories that can promote the application of Pt-based catalysts are also provided. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Apparatus and Process for Controlled Nanomanufacturing Using Catalyst Retaining Structures

NASA Technical Reports Server (NTRS)

Nguyen, Cattien (Inventor)

2013-01-01

An apparatus and method for the controlled fabrication of nanostructures using catalyst retaining structures is disclosed. The apparatus includes one or more modified force microscopes having a nanotube attached to the tip portion of the microscopes. An electric current is passed from the nanotube to a catalyst layer of a substrate, thereby causing a localized chemical reaction to occur in a resist layer adjacent the catalyst layer. The region of the resist layer where the chemical reaction occurred is etched, thereby exposing a catalyst particle or particles in the catalyst layer surrounded by a wall of unetched resist material. Subsequent chemical vapor deposition causes growth of a nanostructure to occur upward through the wall of unetched resist material having controlled characteristics of height and diameter and, for parallel systems, number density.

Methanol-tolerant cathode catalyst composite for direct methanol fuel cells

DOEpatents

Zhu, Yimin; Zelenay, Piotr

2006-09-05

A direct methanol fuel cell (DMFC) having a methanol fuel supply, oxidant supply, and its membrane electrode assembly (MEA) formed of an anode electrode and a cathode electrode with a membrane therebetween, a methanol oxidation catalyst adjacent the anode electrode and the membrane, an oxidant reduction catalyst adjacent the cathode electrode and the membrane, comprises an oxidant reduction catalyst layer of Pt.sub.3Cr/C so that oxidation at the cathode of methanol that crosses from the anode through the membrane to the cathode is reduced with a concomitant increase of net electrical potential at the cathode electrode.

Methanol-Tolerant Cathode Catalyst Composite For Direct Methanol Fuel Cells

DOEpatents

Zhu, Yimin; Zelenay, Piotr

2006-03-21

A direct methanol fuel cell (DMFC) having a methanol fuel supply, oxidant supply, and its membrane electrode assembly (MEA) formed of an anode electrode and a cathode electrode with a membrane therebetween, a methanol oxidation catalyst adjacent the anode electrode and the membrane, an oxidant reduction catalyst adjacent the cathode electrode and the membrane, comprises an oxidant reduction catalyst layer of a platinum-chromium alloy so that oxidation at the cathode of methanol that crosses from the anode through the membrane to the cathode is reduced with a concomitant increase of net electrical potential at the cathode electrode.

Transformation of bulk alloys to oxide nanowires

NASA Astrophysics Data System (ADS)

Lei, Danni; Benson, Jim; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb

2017-01-01

One dimensional (1D) nanostructures offer prospects for enhancing the electrical, thermal, and mechanical properties of a broad range of functional materials and composites, but their synthesis methods are typically elaborate and expensive. We demonstrate a direct transformation of bulk materials into nanowires under ambient conditions without the use of catalysts or any external stimuli. The nanowires form via minimization of strain energy at the boundary of a chemical reaction front. We show the transformation of multimicrometer-sized particles of aluminum or magnesium alloys into alkoxide nanowires of tunable dimensions, which are converted into oxide nanowires upon heating in air. Fabricated separators based on aluminum oxide nanowires enhanced the safety and rate capabilities of lithium-ion batteries. The reported approach allows ultralow-cost scalable synthesis of 1D materials and membranes.

Carbon Dioxide Reduction Systems

NASA Technical Reports Server (NTRS)

Burghardt, Stanley I.; Chandler, Horace W.; Taylor, T. I.; Walden, George

1961-01-01

The Methoxy system for regenerating oxygen from carbon dioxide was studied. Experiments indicate that the reaction between carbon dioxide and hydrogen can be carried out with ease in an efficient manner and with excellent heat conservation. A small reactor capable of handling the C02 expired by three men has been built and operated. The decomposition of methane by therma1,arc and catalytic processes was studied. Both the arc and catalytic processes gave encouraging results with over 90 percent of the methane being decomposed to carbon and hydrogen in some of the catalytic processes. Control of the carbon deposition in both the catalytic and arc processes is of great importance to prevent catalyst deactivation and short circuiting of electrical equipment. Sensitive analytical techniques have been developed for all of the components present in the reactor effluent streams.

Further development and application of polycrystalline metal whiskers

NASA Technical Reports Server (NTRS)

Schladitz, H. J.

1979-01-01

High strength metal whiskers have a larger versatile field of application than monocrystalline whiskers. Although polycrystalline metal whiskers can be used for composites, preferably by extrusion in thermoplastics or by infiltration of resins or metals into whisker networks, the chief application at present may be the production and various use of whisker networks. Such networks can be produced up to high degrees of porosity and besides high mechanical strength, they have high inside surfaces and high electric conductivity. There are for instance, applications concerning construction of electrodes for batteries and fuel cells, catalysts and also new heat-exchanger material, capable of preparing fuel oil and gasoline in order to assist a high-efficiency combustion. The technical application of polycrystalline metal whiskers require their modification as well as the construction of a pilot production unit.

Catalytic method for synthesizing hydrocarbons

DOEpatents

Sapienza, R.S.; Sansone, M.J.; Slegeir, W.A.R.

A method for synthesizing hydrocarbons from carbon monoxide and hydrogen by contacting said gases with a slurry of a catalyst composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants.

Catalytic method for synthesizing hydrocarbons

DOEpatents

Sapienza, Richard S.; Sansone, Michael J.; Slegeir, William A. R.

1984-01-01

A method for synthesizing hydrocarbons from carbon monoxide and hydrogen by contacting said gases with a slurry of a catalyst composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants.

Wood liquefaction with phenol by microwave heating and FTIR evaluation

Treesearch

Gaiyun Li; Chungyun Hse; Tefu Qin

2015-01-01

We examined wood liquefaction using phenol and mixed acid catalysts with microwave heating, and compared that with similar processes that use oil bath heating. The reaction time for microwave heating to achieve a residue content was one sixth, one eighteenth, and one twenty-fourth of that from oil bath heating, respectively, for phenol to wood (P/W) ratios of 2.5/1, 2/...

Thermochemical Conversion: Using Heat and Catalysts to Make Biofuels and Bioproducts

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

None

2013-07-29

This fact sheet discusses the Bioenergy Technologies Office's thermochemical conversion critical technology goal. And, how through the application of heat, robust thermochemical processes can efficiently convert a broad range of biomass.

Experimental study of isopropanol dehydrogenation over amorphous alloy raney nickel catalysts

NASA Astrophysics Data System (ADS)

Xin, Fang; Xu, Min; Li, Xun-Feng; Huai, Xiu-Lan

2013-12-01

The dehydrogenation reaction of isopropanol occurring at low temperature is of great industrial importance. It is a key procedure in isopropanol/acetone/hydrogen chemical heat pump system. An experimental investigation was performed to study the behavior of the liquid phase dehydrogenation of isopropanol over amorphous alloy Raney nickel catalysts. Un-promoted and promoted catalysts were used and their performances were compared under various catalyst amounts, acetone content in the reactant and reaction temperature ranging from 348 K to 355 K. It is found that there exists an optimum catalyst concentration which is about 0.34 g in 300 ml isopropanol. The temperature has evident effect on the reaction. The presence of activities of Fe-promoted catalyst decrease slightly compared to the un-promoted catalyst when the temperature are 348 K and 351 K. Besides, the reaction rate decreases almost linearly with the increase of acetone volume fraction in the reactant.

NiCo as catalyst for magnetically induced dry reforming of methane

NASA Astrophysics Data System (ADS)

Varsano, F.; Bellusci, M.; Provino, A.; Petrecca, M.

2018-03-01

In this paper we report the activation of the dry reforming reaction by induction heating of a NiCo alloy. The catalyst plays a double role, serving both as a promoter for the reforming reaction and producing the heat induced by dissipation of the electromagnetic energy. The elevated temperatures imposed by the reforming reaction suggest the choice of an alloy with a Curie temperature >800°C. In this respect Ni:Co ratio 60:40 was chosen. Alloy active sites for CH4and CO2activation are created by a mechanochemical treatment of the alloy that increases solid-state defects. The catalyst has been successfully tested in a continuous-flow reactor working under atmospheric pressure. Methane conversion and hydrogen production yields have been measured as a function of the applied magnetic field, reactant flow rate and time on stream.

Lagrangian Approach to Jet Mixing and Optimization of the Reactor for Production of Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Povitsky, Alex; Salas, Manuel D.

2001-01-01

This study was motivated by an attempt to optimize the High Pressure carbon oxide (HiPco) process for the production of carbon nanotubes from gaseous carbon oxide, The goal is to achieve rapid and uniform heating of catalyst particles by an optimal arrangement of jets. A mixed Eulerian and Lagrangian approach is implemented to track the temperature of catalyst particles along their trajectories as a function of time. The FLUENT CFD software with second-order upwind approximation of convective terms and an algebraic multigrid-based solver is used. The poor performance of the original reactor configuration is explained in terms of features of particle trajectories. The trajectories most exposed to the hot jets appear to be the most problematic for heating because they either bend towards the cold jet interior or rotate upwind of the mixing zone. To reduce undesirable slow and/or oscillatory heating of catalyst particles, a reactor configuration with three central jets is proposed and the optimal location of the central and peripheral nozzles is determined.

Degradation reaction of Diazo reactive black 5 dye with copper (II) sulfate catalyst in thermolysis treatment.

PubMed

Lau, Yen-Yie; Wong, Yee-Shian; Ang, Tze-Zhang; Ong, Soon-An; Lutpi, Nabilah Aminah; Ho, Li-Ngee

2018-03-01

The theme of present research demonstrates performance of copper (II) sulfate (CuSO 4 ) as catalyst in thermolysis process to treat reactive black 5 (RB 5) dye. During thermolysis without presence of catalyst, heat was converted to thermal energy to break the enthalpy of chemical structure bonding and only 31.62% of color removal. With CuSO 4 support as auxiliary agent, the thermally cleaved molecular structure was further destabilized and reacted with CuSO 4 . Copper ions functioned to delocalize the coordination of π of the lone paired electron in azo bond, C=C bond of the sp 2 carbon to form C-C of the sp 3 amorphous carbon in benzene and naphthalene. Further, the radicals of unpaired electrons were stabilized and RB 5 was thermally decomposed to methyl group. Zeta potential measurement was carried out to analyze the mechanism of RB 5 degradation and measurement at 0 mV verified the critical chemical concentration (CCC) (0.7 g/L copper (II) sulfate), as the maximum 92.30% color removal. The presence of copper (II) sulfate catalyst has remarkably increase the RB 5 dye degradation as the degradation rate constant without catalyst, k 1 is 6.5224 whereas the degradation rate constant with catalyst, k 2 is 25.6810. This revealed the correlation of conversion of thermal energy from heat to break the chemical bond strength, subsequent fragmentation of RB 5 dye molecular mediated by copper (II) sulfate catalyst. The novel framework on thermolysis degradation of molecular structure of RB 5 with respect to the bond enthalpy and interfacial intermediates decomposition with catalyst reaction were determined.

Method of synthesizing bulk transition metal carbide, nitride and phosphide catalysts

DOEpatents

Choi, Jae Soon; Armstrong, Beth L; Schwartz, Viviane

2015-04-21

A method for synthesizing catalyst beads of bulk transmission metal carbides, nitrides and phosphides is provided. The method includes providing an aqueous suspension of transition metal oxide particles in a gel forming base, dropping the suspension into an aqueous solution to form a gel bead matrix, heating the bead to remove the binder, and carburizing, nitriding or phosphiding the bead to form a transition metal carbide, nitride, or phosphide catalyst bead. The method can be tuned for control of porosity, mechanical strength, and dopant content of the beads. The produced catalyst beads are catalytically active, mechanically robust, and suitable for packed-bed reactor applications. The produced catalyst beads are suitable for biomass conversion, petrochemistry, petroleum refining, electrocatalysis, and other applications.

System for trapping and storing gases for subsequent chemical reduction to solids

DOEpatents

Vogel, John S [San Jose, CA; Ognibene, Ted J [Oakland, CA; Bench, Graham S [Livermore, CA; Peaslee, Graham F [Holland, MI

2009-11-03

A system for quantitatively reducing oxide gases. A pre-selected amount of zinc is provided in a vial. A tube is provided in the vial. The zinc and the tube are separated. A pre-selected amount of a catalyst is provided in the tube. Oxide gases are injected into the vial. The vial, tube, zinc, catalyst, and the oxide gases are cryogenically cooled. At least a portion of the vial, tube, zinc, catalyst, and oxide gases are heated.

Method for producing iron-based catalysts

DOEpatents

Farcasiu, Malvina; Kaufman, Phillip B.; Diehl, J. Rodney; Kathrein, Hendrik

1999-01-01

A method for preparing an acid catalyst having a long shelf-life is provided comprising doping crystalline iron oxides with lattice-compatible metals and heating the now-doped oxide with halogen compounds at elevated temperatures. The invention also provides for a catalyst comprising an iron oxide particle having a predetermined lattice structure, one or more metal dopants for said iron oxide, said dopants having an ionic radius compatible with said lattice structure; and a halogen bound with the iron and the metal dopants on the surface of the particle.

Refining of Military Jet Fuels from Shale Oil. Volume I. Part II. Preparation of Laboratory-Scale Fuel Samples.

DTIC Science & Technology

1982-03-01

ON SPEC Meeting Specifications *1 OXY Test Series on In Situ Shale Oil P Pressure (P + N) Paraffins and Naphthenes PHO Test Series on Above-Ground...material, the crude shale is heated and processed through caustic desalt- ing similar to conventional technology. The desalted oil is mixed with recycle...with hot regenerated catalyst. Spent catalyst and oil vapors are disengaqed by -.eans of high temperature cyclones. The spent catalyst first passes

Influence and efficiency of catalytic stripper in organic carbon removal from laboratory generated soot aerosols

EPA Science Inventory

A catalytic stripper (CS) is a device used to remove the semi-volatile, typically organic carbon, fraction by passing raw or diluted exhaust over an oxidation catalyst heated to 300˚C. The oxidation catalyst used in this study is a commercially available diesel oxidation ca...

Investigation of catalytic reduction and filter techniques for simultaneous measurements of NO, NO2, and HNO3 in the stratosphere

NASA Technical Reports Server (NTRS)

Wendt, J.; Fabian, Peter; Flentje, G.; Kourtidis, K.

1994-01-01

A concept for measuring stratospheric NOy-species is presented which utilizes the catalytic reduction of NO2 and HNO3 over heated metal catalysts and the chemisorption of HNO3 on Nylon. Using the Max Planck Institute for Aeronomy (MPAE) chemiluminescent balloon-borne sonde, stratospheric NO and NO2 profiles have been measured since 1983. NO is detected by chemiluminescence produced in reaction with O3 while NO2 needs first to be converted to NO over a heated stainless steel catalyst. To improve this technique for simultaneously measuring HNO3, the catalytic reduction of NO2 and HNO3 over several metal catalysts and the chemisorption of NO2 and HNO3 on Nylon have been investigated in laboratory tests. The results of these tests under simulated stratospheric conditions are presented in detail in this paper. They demonstrate that the simultaneous measurement of NO, NO2 and HNO3 is indeed possible with the combination of stainless steel or Au as a catalyst and a nylon filter.

Applications of low temperature CO-oxidation catalysts to breathable gases

NASA Technical Reports Server (NTRS)

Noordally, Ehsan; Richmond, John R.

1990-01-01

Modifications of tin oxide/precious metal catalysts described for use in CO2 lasers have also been developed for use in other applications; namely, as low temperature CO oxidation components in fire escape hoods/masks for mines, aircrafts, hotels, and offices and in sealed environments, such as hyperbaric chambers and submarines. Tin oxide/precious metal catalysts have been prepared on a variety of high surface area cloth substrates for application in fire escape hoods. These show high and stable CO oxidation capability (10 to the 4th power ppm CO reduced to 10 to the 1st power ppm CO) at GHSV of 37,000 h(-1) with water saturated inlet gas at body heat (37 C) and below. Water vapor plays an important role in the surface state/performance of tin oxide catalyst. Water-resistant formulations have been produced by the introduction of transition metal promoters. Tin oxide/precious metal catalysts have also been developed for CO oxidation in the North Sea diving environment. These are currently in use in a variety of hyperbaric chambers and diving vehicles. Ambient temperature operation and resistance to atmospheric water vapor have been demonstrated, and as a result, they offer a viable alternative to hopcalite or heated catalyst systems. A new range of non-tin oxide based low temperature CO oxidation catalysts is described. They are based on reducible metal oxides promoted with previous metals. Preliminary data on selected materials in the form of both cloth artifacts and shaped pellets are presented. They are expected to be applicable both to the breathable gas application area and to CO2 lasers.

Practical, economical, and eco-friendly starch-supported palladium catalyst for Suzuki coupling reactions.

PubMed

Baran, Talat

2017-06-15

In catalytic systems, the support materials need to be both eco friendly and low cost as well as having high thermal and chemical stability. In this paper, a novel starch supported palladium catalyst, which had these outstanding properties, was designed and its catalytic activity was evaluated in a Suzuki coupling reaction under microwave heating with solvent-free and mild reaction conditions. The starch supported catalyst gave remarkable reaction yields after only 5min as a result of the coupling reaction of the phenyl boronic acid with 23 different substrates, which are bearing aril bromide, iodide, and chloride. The longevity of the catalyst was also investigated, and the catalyst could be reused for 10 runs. The starch supported Pd(II) catalyst yielded remarkable TON (up to 25,000) and TOF (up to 312,500) values by using a simple, fast and eco-friendly method. In addition, the catalytic performance of the catalyst was tested against different commercial palladium catalysts, and the green starch supported catalyst had excellent selectivity. The catalytic tests showed that the novel starch based palladium catalyst proved to be an economical and practical catalyst for the synthesis of biaryl compounds. Copyright © 2017 Elsevier Inc. All rights reserved.

Photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts

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

Hill, Craig L.; Gueletii, Iourii V.; Song, Jie

This disclosure relates to photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts. In certain embodiments, the disclosure relates to compositions comprising water, a complex of a tetra-metal oxide cluster and VW.sub.9O.sub.34 ligands, and a photosensitizer. Typically, the metal oxide cluster is Co. In certain embodiments, the disclosure relates to electrodes and other devices comprising water oxidation catalysts disclosed herein and uses in generating fuels and electrical power from solar energy.

Catalyzed enzyme electrodes

DOEpatents

Zawodzinski, Thomas A.; Wilson, Mahlon S.; Rishpon, Judith; Gottesfeld, Shimshon

1993-01-01

An enzyme electrode is prepared with a composite coating on an electrical conductor. The composite coating is formed from a casting solution of a perfluorosulfonic acid polymer, an enzyme, and a carbon supported catalyst. The solution may be cast directly on the conductor surface or may be formed as a membrane and applied to the surface. The perfluorosulfonic acid ionomer formed from the casting solution provides an insoluble biocompatible protective matrix for the enzyme and acts to retain the enzyme for long term availability in the electrode structure. The carbon supported catalyst provides catalytic sites throughout the layer for the oxidation of hydrogen peroxide from the enzyme reactions. The carbon support then provides a conductive path for establishing an electrical signal to the electrical conductor. In one embodiment, the electrical conductor is a carbon cloth that permits oxygen or other gas to be introduced to the perfluorosulfonic polymer to promote the enzyme reaction independent of oxygen in the solution being tested.

Strong Schottky barrier reduction at Au-catalyst/GaAs-nanowire interfaces by electric dipole formation and Fermi-level unpinning.

PubMed

Suyatin, Dmitry B; Jain, Vishal; Nebol'sin, Valery A; Trägårdh, Johanna; Messing, Maria E; Wagner, Jakob B; Persson, Olof; Timm, Rainer; Mikkelsen, Anders; Maximov, Ivan; Samuelson, Lars; Pettersson, Håkan

2014-01-01

Nanoscale contacts between metals and semiconductors are critical for further downscaling of electronic and optoelectronic devices. However, realizing nanocontacts poses significant challenges since conventional approaches to achieve ohmic contacts through Schottky barrier suppression are often inadequate. Here we report the realization and characterization of low n-type Schottky barriers (~0.35 eV) formed at epitaxial contacts between Au-In alloy catalytic particles and GaAs-nanowires. In comparison to previous studies, our detailed characterization, employing selective electrical contacts defined by high-precision electron beam lithography, reveals the barrier to occur directly and solely at the abrupt interface between the catalyst and nanowire. We attribute this lowest-to-date-reported Schottky barrier to a reduced density of pinning states (~10(17) m(-2)) and the formation of an electric dipole layer at the epitaxial contacts. The insight into the physical mechanisms behind the observed low-energy Schottky barrier may guide future efforts to engineer abrupt nanoscale electrical contacts with tailored electrical properties.

Efficient photo-catalytic degradation of malachite green using nickel tungstate material as photo-catalyst.

PubMed

Helaïli, N; Boudjamaa, A; Kebir, M; Bachari, K

2017-03-01

The present study focused on the evaluation of photo-catalytic and photo-electrochemical properties of the photo-catalyst based on nickel tungstate material prepared by a nitrate method through the degradation of malachite green (MG) dye's. The effect of catalyst loading and dye concentration was examined. Physico-chemical, optical, electrical, electrochemical, and photo-electrochemical properties of the prepared material were analyzed by X-ray diffraction (XRD), fourier transform-infrared spectroscopy (FTIR), BET analysis, optical reflectance diffuse (DR), scanning electron microscopy (SEM/EDX), electrical conductivity, cyclic voltammetry (CV), current intensity, mott-shottky, and nyquist. XRD revealed the formation of monoclinic structure with a small particle size. BET surface area of the sample was around 10 m 2 /g. The results show that the degradation of MG was more than 80%, achieved after 3 h of irradiation at pH 4.6 and with a catalyst loading of 75 mg. Also, it was found that the dye photo-degradation obeyed the pseudo-first order kinetic via Langmuir Hinshelwood model.

Solid oxide MEMS-based fuel cells

DOEpatents

Jankowksi, Alan F.; Morse, Jeffrey D.

2007-03-13

A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

Solid polymer MEMS-based fuel cells

DOEpatents

Jankowski, Alan F [Livermore, CA; Morse, Jeffrey D [Pleasant Hill, CA

2008-04-22

A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

Economic analysis of electric heating based on critical electricity price

NASA Astrophysics Data System (ADS)

Xie, Feng; Sun, Zhijie; Zhou, Xinnan; Fu, Chengran; Yang, Jie

2018-06-01

The State Grid Corporation of China proposes an alternative energy strategy, which will make electric heating an important task in the field of residential electricity consumption. This article takes this as the background, has made the detailed introduction to the inhabitant electric heating technology, and take the Zhangjiakou electric panels heating technology as an example, from the expense angle, has carried on the analysis to the electric panels heating economy. In the field of residential heating, electric panels operating costs less than gas boilers. After customers implying energy-saving behavior, electric panels operating cost is even lower than coal-fired boilers. The critical price is higher than the execution price, which indicates that the economic performance of the electric panels is significantly higher than that of the coal boiler.

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

Lercher, Johannes

PNNL’s catalysis research is serving as a catalyst for changing how our nation will secure a strong, clean energy future. Senior Physical Chemist Johannes Lercher leads an award-winning team that is developing catalysts that efficiently make fuels from alternate feedstocks, such as biomass, and can store electrical energy in chemical bonds. The researchers are also creating catalysts that can increase vehicle fuel efficiency, while simultaneously cutting emissions. About 80 percent of all man-made materials — from plastics to pharmaceuticals — are made using catalysts. Through PNNL’s Institute for Integrated Catalysis, Johannes and colleagues study how to speed the catalysis reactionmore » process for manufacturers, which ultimately cuts costs and production time.« less

Solid state gas sensors for detection of explosives and explosive precursors

NASA Astrophysics Data System (ADS)

Chu, Yun

The increased number of terrorist attacks using improvised explosive devices (IEDs) over the past few years has made the trace detection of explosives a priority for the Department of Homeland Security. Considerable advances in early detection of trace explosives employing spectroscopic detection systems and other sensing devices have been made and have demonstrated outstanding performance. However, modern IEDs are not easily detectable by conventional methods and terrorists have adapted to avoid using metallic or nitro groups in the manufacturing of IEDs. Instead, more powerful but smaller compounds, such as TATP are being more frequently used. In addition, conventional detection techniques usually require large capital investment, labor costs and energy input and are incapable of real-time identification, limiting their application. Thus, a low cost detection system which is capable of continuous online monitoring in a passive mode is needed for explosive detection. In this dissertation, a thermodynamic based thin film gas sensor which can reliably detect various explosive compounds was developed and demonstrated. The principle of the sensors is based on measuring the heat effect associated with the catalytic decomposition of explosive compounds present in the vapor phase. The decomposition mechanism is complicated and not well known, but it can be affected by many parameters including catalyst, reaction temperature and humidity. Explosives that have relatively high vapor pressure and readily sublime at room temperature, like TATP and 2, 6-DNT, are ideal candidate for vapor phase detection using the thermodynamic gas sensor. ZnO, W2O 3, V2O5 and SnO2 were employed as catalysts. This sensor exhibited promising sensitivity results for TATP, but poor selectivity among peroxide based compounds. In order to improve the sensitivity and selectivity of the thermodynamic sensor, a Pd:SnO2 nanocomposite was fabricated and tested as part of this dissertation. A combinatorial chemistry techniques were used for catalyst discovery. Specially, a series of tin oxide catalysts with continuous varying composition of palladium were fabricated to screen for the optimum Pd loading to maximize specificity. Experimental results suggested that sensors with a 12 wt.% palladium loading generated the highest sensitivity while a 8 wt.% palladium loading provided greatest selectivity. XPS and XRD were used to study how palladium doping level affects the oxidation state and crystal structure of the nanocomposite catalyst. As with any passive detection system, a necessary theme of this dissertation was the mitigation of false positive. Toward this end, an orthogonal detection system comprised of two independent sensing platforms sharing one catalyst was demonstrated using TATP, 2, 6-DNT and ammonium nitrate as target molecules. The orthogonal sensor incorporated a thermodynamic based sensing platform to measure the heat effect associated with the decomposition of explosive molecules, and a conductometric sensing platform that monitors the change in electrical conductivity of the same catalyst when exposed to the explosive substances. Results indicate that the orthogonal sensor generates an effective response to explosives presented at part per billion level. In addition, with two independent sensing platforms, a built-in redundancy of results could be expected to minimize false positive.

A Review of Study on Thermal Energy Transport System by Synthesis and Decomposition Reactions of Methanol

NASA Astrophysics Data System (ADS)

Liu, Qiusheng; Yabe, Akira; Kajiyama, Shiro; Fukuda, Katsuya

The study on thermal energy transport system by synthesis and decomposition reactions of methanol was reviewed. To promote energy conservation and global environment protection, a two-step liquid-phase methanol synthesis process, which starts with carbonylation of methanol to methyl formate, then followed by the hydrogenolysis of the formate, was studied to recover wasted or unused discharged heat from industrial sources for the thermal energy demands of residential and commercial areas by chemical reactions. The research and development of the system were focused on the following three points. (1) Development of low-temperature decomposition and synthetic catalysts, (2) Development of liquid phase reactor (heat exchanger accompanying chemical reaction), (3) Simulation of the energy transport efficiency of entire system which contains heat recovery and supply sections. As the result of the development of catalyst, promising catalysts which agree with the development purposes for the methyl formate decomposition reaction and the synthetic reaction are being developed though some studies remain for the methanol decomposition and synthetic reactions. In the fundamental development of liquid phase reactor, the solubilities of CO and H2 gases in methanol and methyl formate were measured by the method of total pressure decrease due to absorption under pressures up to 1500kPa and temperatures up to 140°C. The diffusivity of CO gas in methanol was determined by measuring the diameter and solution time of single CO bubbles in methanol. The chemical reaction rate of methanol synthesis by hydrogenolysis of methyl formate was measured using a plate-type of Raney copper catalyst in a reactor with rectangular channel and in an autoclave reactor. The reaction characteristics were investigated by carrying out the experiments at various temperatures, flow rates and at various catalyst development conditions. We focused on the effect of Raney copper catalyst thickness on the liquid-phase chemical reaction by varying the development time of the catalyst. Investigation results of the catalyst such as surface area, pore radius, lattice size, and photographs of scanning electron microscope (SEM) were also given. In the simulation of energy transport efficiency of this system, by simulating the energy transfer system using two-step liquid phase methanol decomposition and synthetic reactions, and comparing with the technology so far, it can be expected that an innovative energy transfer system is possible to realize.

Growth of low temperature silicon nano-structures for electronic and electrical energy generation applications.

PubMed

Gabrielyan, Nare; Saranti, Konstantina; Manjunatha, Krishna Nama; Paul, Shashi

2013-02-15

This paper represents the lowest growth temperature for silicon nano-wires (SiNWs) via a vapour-liquid-solid method, which has ever been reported in the literature. The nano-wires were grown using plasma-enhanced chemical vapour deposition technique at temperatures as low as 150°C using gallium as the catalyst. This study investigates the structure and the size of the grown silicon nano-structure as functions of growth temperature and catalyst layer thickness. Moreover, the choice of the growth temperature determines the thickness of the catalyst layer to be used.The electrical and optical characteristics of the nano-wires were tested by incorporating them in photovoltaic solar cells, two terminal bistable memory devices and Schottky diode. With further optimisation of the growth parameters, SiNWs, grown by our method, have promising future for incorporation into high performance electronic and optical devices.

Growth of low temperature silicon nano-structures for electronic and electrical energy generation applications

PubMed Central

2013-01-01

This paper represents the lowest growth temperature for silicon nano-wires (SiNWs) via a vapour-liquid–solid method, which has ever been reported in the literature. The nano-wires were grown using plasma-enhanced chemical vapour deposition technique at temperatures as low as 150°C using gallium as the catalyst. This study investigates the structure and the size of the grown silicon nano-structure as functions of growth temperature and catalyst layer thickness. Moreover, the choice of the growth temperature determines the thickness of the catalyst layer to be used. The electrical and optical characteristics of the nano-wires were tested by incorporating them in photovoltaic solar cells, two terminal bistable memory devices and Schottky diode. With further optimisation of the growth parameters, SiNWs, grown by our method, have promising future for incorporation into high performance electronic and optical devices. PMID:23413969

Fuel cell electric power production

DOEpatents

Hwang, Herng-Shinn; Heck, Ronald M.; Yarrington, Robert M.

1985-01-01

A process for generating electricity from a fuel cell includes generating a hydrogen-rich gas as the fuel for the fuel cell by treating a hydrocarbon feed, which may be a normally liquid feed, in an autothermal reformer utilizing a first monolithic catalyst zone having palladium and platinum catalytic components therein and a second, platinum group metal steam reforming catalyst. Air is used as the oxidant in the hydrocarbon reforming zone and a low oxygen to carbon ratio is maintained to control the amount of dilution of the hydrogen-rich gas with nitrogen of the air without sustaining an insupportable amount of carbon deposition on the catalyst. Anode vent gas may be utilized as the fuel to preheat the inlet stream to the reformer. The fuel cell and the reformer are preferably operated at elevated pressures, up to about a pressure of 150 psia for the fuel cell.

Co-Production of Electricity and Hydrogen Using a Novel Iron-based Catalyst

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

Hilaly, Ahmad; Georgas, Adam; Leboreiro, Jose

2011-09-30

The primary objective of this project was to develop a hydrogen production technology for gasification applications based on a circulating fluid-bed reactor and an attrition resistant iron catalyst. The work towards achieving this objective consisted of three key activities: Development of an iron-based catalyst suitable for a circulating fluid-bed reactor; Design, construction, and operation of a bench-scale circulating fluid-bed reactor system for hydrogen production; Techno-economic analysis of the steam-iron and the pressure swing adsorption hydrogen production processes. This report describes the work completed in each of these activities during this project. The catalyst development and testing program prepared and iron-basedmore » catalysts using different support and promoters to identify catalysts that had sufficient activity for cyclic reduction with syngas and steam oxidation and attrition resistance to enable use in a circulating fluid-bed reactor system. The best performing catalyst from this catalyst development program was produced by a commercial catalyst toll manufacturer to support the bench-scale testing activities. The reactor testing systems used during material development evaluated catalysts in a single fluid-bed reactor by cycling between reduction with syngas and oxidation with steam. The prototype SIP reactor system (PSRS) consisted of two circulating fluid-bed reactors with the iron catalyst being transferred between the two reactors. This design enabled demonstration of the technical feasibility of the combination of the circulating fluid-bed reactor system and the iron-based catalyst for commercial hydrogen production. The specific activities associated with this bench-scale circulating fluid-bed reactor systems that were completed in this project included design, construction, commissioning, and operation. The experimental portion of this project focused on technical demonstration of the performance of an iron-based catalyst and a circulating fluid-bed reactor system for hydrogen production. Although a technology can be technically feasible, successful commercial deployment also requires that a technology offer an economic advantage over existing commercial technologies. To effective estimate the economics of this steam-iron process, a techno-economic analysis of this steam iron process and a commercial pressure swing adsorption process were completed. The results from this analysis described in this report show the economic potential of the steam iron process for integration with a gasification plant for coproduction of hydrogen and electricity.« less

Preparation and Characterization of NiMo/Al2O3Catalyst for Hydrocracking Processing

NASA Astrophysics Data System (ADS)

Widiyadi, Aditya; Guspiani, Gema Adil; Riady, Jeffry; Andreanto, Rikky; Chaiunnisa, Safina Dea; Widayat

2018-02-01

Hydrocracking is a chemical process used in petroleum refineries for converting high boiling hydrocarbons in petroleum crude oils to more valuable lower boiling products such as gasoline, kerosene, and diesel oil that operate at high temperature and pressure. Catalyst was used in hydrocracking to reduce temperature and pressure. Hydrocracking catalyst are composed of active components and support. Alumina is widely used in hydrocracking process as catalyst support due to its high surface area, high thermal stability, and low prices. The objective of this research was preparated NiMo/Al2O3 catalyst that used as hydrocracking catalyst. Catalyst was synthesized by wetness impregnation method and simple heating method with various kind of Al2O3. The physicochemical properties of catalyst were investigated by X-ray diffraction (XRD) to determine type of crystal and scanning electron microscopy (SEM) to determine morphology of the catalyst. The NiMo/Al2O3 catalyst prepared by aluminium potassium sulfate dodecahydrate exhibited the highest crystallinity of 90.23% and it is clear that MoO3 and NiO crystallites are highly dispersed on the NiMo/Al2O3 catalyst which indicates as the best catalyst. The catalytic activity in hydrocracking process was successfully examined to convert fatty acid into hydrocarbon.

Catalyst surfaces for the chromous/chromic redox couple

NASA Technical Reports Server (NTRS)

Giner, J. D.; Cahill, K. J. (Inventor)

1981-01-01

An electricity producing cell of the reduction-oxidation (REDOX) type divided into two compartments by a membrane is disclosed. A ferrous/ferric couple in a chloride solution serves as a cathode fluid to produce a positive electric potential. A chromic/chromous couple in a chloride solution serves as an anode fluid to produce a negative potential. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which has been added to the anode fluid. If the REDOX cell is then discharged, the lead deplates from the negative electrode and the metal coating on the electrode acts as a catalyst to increase current density.

Process for producing ethanol from syngas

DOEpatents

Krause, Theodore R; Rathke, Jerome W; Chen, Michael J

2013-05-14

The invention provides a method for producing ethanol, the method comprising establishing an atmosphere containing methanol forming catalyst and ethanol forming catalyst; injecting syngas into the atmosphere at a temperature and for a time sufficient to produce methanol; and contacting the produced methanol with additional syngas at a temperature and for a time sufficient to produce ethanol. The invention also provides an integrated system for producing methanol and ethanol from syngas, the system comprising an atmosphere isolated from the ambient environment; a first catalyst to produce methanol from syngas wherein the first catalyst resides in the atmosphere; a second catalyst to product ethanol from methanol and syngas, wherein the second catalyst resides in the atmosphere; a conduit for introducing syngas to the atmosphere; and a device for removing ethanol from the atmosphere. The exothermicity of the method and system obviates the need for input of additional heat from outside the atmosphere.

Process reduces pore diameters to produce superior filters

NASA Technical Reports Server (NTRS)

Todd, H. H.

1966-01-01

Porous metal structure with very small pore diameters is produced by heating the structure in oxygen for an oxidized surface layer, cooling it, and heating it in hydrogen to deoxidize the oxidized portion. Such structures are superior catalyst beds and filters.

Nitrogen-doped carbon-supported cobalt-iron oxygen reduction catalyst

DOEpatents

Zelenay, Piotr; Wu, Gang

2014-04-29

A Fe--Co hybrid catalyst for oxygen reaction reduction was prepared by a two part process. The first part involves reacting an ethyleneamine with a cobalt-containing precursor to form a cobalt-containing complex, combining the cobalt-containing complex with an electroconductive carbon supporting material, heating the cobalt-containing complex and carbon supporting material under conditions suitable to convert the cobalt-containing complex and carbon supporting material into a cobalt-containing catalyst support. The second part of the process involves polymerizing an aniline in the presence of said cobalt-containing catalyst support and an iron-containing compound under conditions suitable to form a supported, cobalt-containing, iron-bound polyaniline species, and subjecting said supported, cobalt-containing, iron bound polyaniline species to conditions suitable for producing a Fe--Co hybrid catalyst.

Metal catalysts for steam reforming of tar derived from the gasification of lignocellulosic biomass.

PubMed

Li, Dalin; Tamura, Masazumi; Nakagawa, Yoshinao; Tomishige, Keiichi

2015-02-01

Biomass gasification is one of the most important technologies for the conversion of biomass to electricity, fuels, and chemicals. The main obstacle preventing the commercial application of this technology is the presence of tar in the product gas. Catalytic reforming of tar appears a promising approach to remove tar and supported metal catalysts are among the most effective catalysts. Nevertheless, improvement of catalytic performances including activity, stability, resistance to coke deposition and aggregation of metal particles, as well as catalyst regenerability is greatly needed. This review focuses on the design and catalysis of supported metal catalysts for the removal of tar in the gasification of biomass. The recent development of metal catalysts including Rh, Ni, Co, and their alloys for steam reforming of biomass tar and tar model compounds is introduced. The role of metal species, support materials, promoters, and their interfaces is described. Copyright © 2014 Elsevier Ltd. All rights reserved.

Transformation of bulk alloys to oxide nanowires.

PubMed

Lei, Danni; Benson, Jim; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb

2017-01-20

One dimensional (1D) nanostructures offer prospects for enhancing the electrical, thermal, and mechanical properties of a broad range of functional materials and composites, but their synthesis methods are typically elaborate and expensive. We demonstrate a direct transformation of bulk materials into nanowires under ambient conditions without the use of catalysts or any external stimuli. The nanowires form via minimization of strain energy at the boundary of a chemical reaction front. We show the transformation of multimicrometer-sized particles of aluminum or magnesium alloys into alkoxide nanowires of tunable dimensions, which are converted into oxide nanowires upon heating in air. Fabricated separators based on aluminum oxide nanowires enhanced the safety and rate capabilities of lithium-ion batteries. The reported approach allows ultralow-cost scalable synthesis of 1D materials and membranes. Copyright © 2017, American Association for the Advancement of Science.

Dual properties of a hydrogen oxidation Ni-catalyst entrapped within a polymer promote self-defense against oxygen

DOE PAGES

Oughli, Alaa A.; Ruff, Adrian; Boralugodage, Nilusha Priyadarshani; ...

2018-02-28

A bio-inspired O 2 sensitive nickel catalyst dispersed in a hydrophobic and redox-silent polymer matrix shows enhanced stability for catalytic H 2 oxidation as well as O 2 tolerance. A simple but efficient electrode design separates the catalyst into two different reaction layers to promote different reactivity on the catalyst. (1) close to the electrode surface, the catalyst can directly exchange electrons with the electrode and generate current from H 2 oxidation; and (2) at the outer film boundary, the electrolyte exposed layer is electrically isolated from the electrode, which enables the H 2 reduced Ni-complex to convert O 2more » to H 2O and thus provides protection to the O 2-sensitive inner reaction layer. This strategy solves one of the biggest limitations of these otherwise outstanding catalysts and could be used to protect other similar catalysts whose wider application is currently limited by sensitivity towards oxygen.« less

Need for optimizing catalyst loading for achieving affordable microbial fuel cells.

PubMed

Singh, Inderjeet; Chandra, Amreesh

2013-08-01

Microbial fuel cell (MFC) technology is a promising technology for electricity production together with simultaneous water treatment. Catalysts play an important role in deciding the MFC performance. In most reports, effect of catalyst - both type and quantity is not optimized. In this paper, synthesis of nanorods of MnO2-catalyst particles for application in Pt-free MFCs is reported. The effect of catalyst loading i.e., weight ratio, with respect to conducting element and binder has been optimized by employing large number of combinations. Using simple theoretical model, it is shown that too high (or low) concentration of catalysts result in loss of MFC performance. The operation of MFC has been investigated using domestic wastewater as source of bio-waste for obtaining real world situation. Maximum power density of ∼61 mW/m(2) was obtained when weight ratio of catalyst and conducting species was 1:1. Suitable reasons are given to explain the outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dual properties of a hydrogen oxidation Ni-catalyst entrapped within a polymer promote self-defense against oxygen

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

Oughli, Alaa A.; Ruff, Adrian; Boralugodage, Nilusha Priyadarshani

A bio-inspired O 2 sensitive nickel catalyst dispersed in a hydrophobic and redox-silent polymer matrix shows enhanced stability for catalytic H 2 oxidation as well as O 2 tolerance. A simple but efficient electrode design separates the catalyst into two different reaction layers to promote different reactivity on the catalyst. (1) close to the electrode surface, the catalyst can directly exchange electrons with the electrode and generate current from H 2 oxidation; and (2) at the outer film boundary, the electrolyte exposed layer is electrically isolated from the electrode, which enables the H 2 reduced Ni-complex to convert O 2more » to H 2O and thus provides protection to the O 2-sensitive inner reaction layer. This strategy solves one of the biggest limitations of these otherwise outstanding catalysts and could be used to protect other similar catalysts whose wider application is currently limited by sensitivity towards oxygen.« less

Fuel processing in integrated micro-structured heat-exchanger reactors

NASA Astrophysics Data System (ADS)

Kolb, G.; Schürer, J.; Tiemann, D.; Wichert, M.; Zapf, R.; Hessel, V.; Löwe, H.

Micro-structured fuel processors are under development at IMM for different fuels such as methanol, ethanol, propane/butane (LPG), gasoline and diesel. The target application are mobile, portable and small scale stationary auxiliary power units (APU) based upon fuel cell technology. The key feature of the systems is an integrated plate heat-exchanger technology which allows for the thermal integration of several functions in a single device. Steam reforming may be coupled with catalytic combustion in separate flow paths of a heat-exchanger. Reactors and complete fuel processors are tested up to the size range of 5 kW power output of a corresponding fuel cell. On top of reactor and system prototyping and testing, catalyst coatings are under development at IMM for numerous reactions such as steam reforming of LPG, ethanol and methanol, catalytic combustion of LPG and methanol, and for CO clean-up reactions, namely water-gas shift, methanation and the preferential oxidation of carbon monoxide. These catalysts are investigated in specially developed testing reactors. In selected cases 1000 h stability testing is performed on catalyst coatings at weight hourly space velocities, which are sufficiently high to meet the demands of future fuel processing reactors.

Investigation of the characteristics of a compact steam reformer integrated with a water-gas shift reactor

NASA Astrophysics Data System (ADS)

Seo, Yong-Seog; Seo, Dong-Joo; Seo, Yu-Taek; Yoon, Wang-Lai

The objective of this study is to investigate numerically a compact steam methane reforming (SMR) system integrated with a water-gas shift (WGS) reactor. Separate numerical models are established for the combustion part, SMR and WGS reaction bed. The concentration of species at the exits of the SMR and WGS bed, and the temperatures in the WGS bed are in good agreement with the measured data. Heat transfer to the catalyst beds and the catalytic reactions in the SMR and WGS catalyst bed are investigated as a function of the operation parameters. The conversion of methane at the exit of the SMR catalyst bed is calculated to be 87%, and the carbon monoxide concentration at the outlet of the WGS bed is estimated to be 0.45%. The effects of the cooling heat flux at the outside wall of the system and steam-to-carbon (S/C) ratio are also examined. As the cooling heat flux increases, both the methane conversion and carbon monoxide content are reduced in the SMR bed, and the carbon monoxide conversion is improved in the WGS bed. Both methane conversion and carbon dioxide reduction increase with increasing steam-to-carbon ratio.

Chitosan-microreactor: a versatile approach for heterogeneous organic synthesis in microfluidics.

PubMed

Basavaraju, K C; Sharma, Siddharth; Singh, Ajay K; Im, Do Jin; Kim, Dong-Pyo

2014-07-01

Microreactors have been proven to be efficient tools for a variety of homogeneous organic transformations due to their mixing efficiency, which results in very fast reactions, better heat and mass transfer, and simple scale-up. However, in heterogeneous catalytic reactions each catalyst needs an individual substrate as support. Herein, a versatile approach to immobilize metal catalysts on chitosan as a common substrate is presented. Chitosan, accommodating many metal catalysts, is grafted onto the microchannel surface as nanobrush. The versatility, catalytic efficiency, and stability/durability of the microreactor are demonstrated for a number of organic transformations involving various metal compounds as catalysts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method for generating a highly reactive plasma for exhaust gas aftertreatment and enhanced catalyst reactivity

DOEpatents

Whealton, John H.; Hanson, Gregory R.; Storey, John M.; Raridon, Richard J.; Armfield, Jeffrey S.; Bigelow, Timothy S.; Graves, Ronald L.

2002-01-01

A method for non-thermal plasma aftertreatment of exhaust gases the method comprising the steps of providing short risetime, high frequency, high power bursts of low-duty factor microwaves sufficient to generate a plasma discharge and passing a gas to be treated through the discharge so as to cause dissociative reduction of the exhaust gases and enhanced catalyst reactivity through application of the pulsed microwave fields directly to the catalyst material sufficient to cause a polarizability catastrophe and enhanced heating of the metal crystallite particles of the catalyst, and in the presence or absence of the plasma. The invention also includes a reactor for aftertreatment of exhaust gases.

Simulation and energy analysis of distributed electric heating system

NASA Astrophysics Data System (ADS)

Yu, Bo; Han, Shenchao; Yang, Yanchun; Liu, Mingyuan

2018-02-01

Distributed electric heating system assistssolar heating systemby using air-source heat pump. Air-source heat pump as auxiliary heat sourcecan make up the defects of the conventional solar thermal system can provide a 24 - hour high - efficiency work. It has certain practical value and practical significance to reduce emissions and promote building energy efficiency. Using Polysun software the system is simulated and compared with ordinary electric boiler heating system. The simulation results show that upon energy request, 5844.5kW energy is saved and 3135kg carbon - dioxide emissions are reduced and5844.5 kWhfuel and energy consumption is decreased with distributed electric heating system. Theeffect of conserving energy and reducing emissions using distributed electric heating systemis very obvious.

Application of Electro-Fenton Technology to Remediation of Polluted Effluents by Self-Sustaining Process

PubMed Central

Fernández de Dios, Maria Ángeles; Iglesias, Olaia; Pazos, Marta; Sanromán, Maria Ángeles

2014-01-01

The applicability of electro-Fenton technology to remediation of wastewater contaminated by several organic pollutants such as dyes and polycyclic aromatic hydrocarbons has been evaluated using iron-enriched zeolite as heterogeneous catalyst. The electro-Fenton technology is an advanced oxidation process that is efficient for the degradation of organic pollutants, but it suffers from the high operating costs due to the need for power investment. For this reason, in this study microbial fuel cells (MFCs) were designed in order to supply electricity to electro-Fenton processes and to achieve high treatment efficiency at low cost. Initially, the effect of key parameters on the MFC power generation was evaluated. Afterwards, the degradation of Reactive Black 5 dye and phenanthrene was evaluated in an electro-Fenton reactor, containing iron-enriched zeolite as catalyst, using the electricity supplied by the MFC. Near complete dye decolourization and 78% of phenanthrene degradation were reached after 90 min and 30 h, respectively. Furthermore, preliminary reusability tests of the developed catalyst showed high degradation levels for successive cycles. The results permit concluding that the integrated system is adequate to achieve high treatment efficiency with low electrical consumption. PMID:24723828

HOMOGENEOUS NUCLEAR REACTOR

DOEpatents

Hammond, R.P.; Busey, H.M.

1959-02-17

Nuclear reactors of the homogeneous liquid fuel type are discussed. The reactor is comprised of an elongated closed vessel, vertically oriented, having a critical region at the bottom, a lower chimney structure extending from the critical region vertically upwardly and surrounded by heat exchanger coils, to a baffle region above which is located an upper chimney structure containing a catalyst functioning to recombine radiolyticallydissociated moderator gages. In operation the liquid fuel circulates solely by convection from the critical region upwardly through the lower chimney and then downwardly through the heat exchanger to return to the critical region. The gases formed by radiolytic- dissociation of the moderator are carried upwardly with the circulating liquid fuel and past the baffle into the region of the upper chimney where they are recombined by the catalyst and condensed, thence returning through the heat exchanger to the critical region.

Catalytic devices

DOEpatents

Liu, Ming; Zhang, Xiang

2018-01-23

This disclosure provides systems, methods, and apparatus related to catalytic devices. In one aspect, a device includes a substrate, an electrically insulating layer disposed on the substrate, a layer of material disposed on the electrically insulating layer, and a catalyst disposed on the layer of material. The substrate comprises an electrically conductive material. The substrate and the layer of material are electrically coupled to one another and configured to have a voltage applied across them.

Activity Tests of Macro-Meso Porous Catalysts over Metal Foam Plate for Steam Reforming of Bio-Ethanol.

PubMed

Park, No-Kuk; Jeong, Yong Han; Kang, Misook; Lee, Tae Jin

2018-09-01

The catalytic activity of a macro-mesoporous catalyst coated on a metal foam plate in the reforming of bio-ethanol to synthesis gas was investigated. The catalysts were prepared by coating a support with a noble metal and transition metal. The catalytic activity for the production of synthetic gas by the reforming of bio-ethanol was compared according to the support material, reaction temperature, and steam/carbon ratio. The catalysts coated on the metal foams were prepared using a template method, in which macro-pores and meso-pores were formed by mixing polymer beads. In particular, the thermodynamic equilibrium composition of bio-ethanol reforming with the reaction temperature and steam/carbon ratio to produce synthetic gas was examined using the HSC (Enthalpy-Entropy-Heat capacity) chemistry program in this study. The composition of hydrogen and carbon monoxide in the reformate gas produced by steam reforming over the Rh/Ni-Ce-Zr/Al2O3-based pellet type catalysts and metal foam catalysts that had been coated with the Rh/Al-Ce-Zr-based catalysts was investigated by experimental activity tests. The activity of the metal foam catalyst was higher than that of the pellet type catalyst.

Co- and defect-rich carbon nanofiber films as a highly efficient electrocatalyst for oxygen reduction

NASA Astrophysics Data System (ADS)

Kim, Il To; Song, Myeong Jun; Shin, Seoyoon; Shin, Moo Whan

2018-03-01

Many efforts are continuously devoted to developing high-efficiency, low-cost, and highly scalable oxygen reduction reaction (ORR) electrocatalysts to replace precious metal catalysts. Herein, we successfully synthesize Co- and defect-rich carbon nanofibers (CNFs) using an efficient heat treatment approach involving the pyrolysis of electrospun fibers at 370 °C under air. The heat treatment process produces Co-decorated CNFs with a high Co mass ratio, enriched pyridinic N, Co-pyridinic Nx clusters, and defect-rich carbon structures. The synergistic effects from composition and structural changes in the designed material increase the number of catalytically active sites for the ORR in an alkaline solution. The prepared Co- and defect-rich CNFs exhibit excellent ORR activities with a high ORR onset potential (0.954 V vs. RHE), a large reduction current density (4.426 mA cm-2 at 0.40 V), and a nearly four-electron pathway. The catalyst also exhibits a better long-term durability than commercial Pt/C catalysts. This study provides a novel hybrid material as an efficient ORR catalyst and important insight into the design strategy for CNF-based hybrid materials as electrochemical electrodes.

Process modifications for improved carbon fiber composites: Alleviation of the electrical hazards problem

NASA Technical Reports Server (NTRS)

Ramohalli, K.

1980-01-01

Attempts to alleviate carbon-fiber-composite electrical hazards during airplane crash fires through fiber gasification are described. Thermogravimetric and differential scanning calorimetric experiments found several catalysts that caused fibers to combust when composites were exposed to test fires. Composites were tested in the 'Burn-Bang' apparatus and in high voltage electrical detection grid apparatus. In a standard three minute burn test modified composites released no fibers, while state-of-the-art composites released several hundred fiber fragments. Expected service life with and without catalytic modification was studied and electron microscopy and X-ray microanalysis furnished physical appearance and chemical composition data. An acrylic acid polymer fiber coating was developed that wet the carbon fiber surface uniformly with the catalyst, providing a marked contrast with the uneven coats obtained by solution-dipping.

Fabrication and electrical characterization of silicon nanowires based resistors

NASA Astrophysics Data System (ADS)

Ni, L.; Demami, F.; Rogel, R.; Salaün, A. C.; Pichon, L.

2009-11-01

Silicon nanowires (SiNWs) are synthesized via the Vapor-Liquid-Solid (VLS) mechanism using gold (Au) as metal catalyst and silane (SiH4) as precursor gas. Au nanoparticles are employed as liquid droplets catalysis during the SiNWs growth performed in a hot wall LPCVD reactor at 480°C and 40 Pa. SiNWs local synthesis at micron scale is demonstrated using classical optical photolithography process. SiNWs grow with high density anchored at the dedicated catalyst islands. This resulting network is used to interconnect two heavily doped polysilicon interdigitated electrodes leading to the formation of electrical resistors in a coplanar structure. Current-voltage (I-V) characteristics highlight a symmetric shape. The temperature dependence of the electrical resistance is activated, with activation energy of 0.47 eV at temperatures greater than 300K.

Hydrodeoxygenation of prairie cordgrass bio-oil over Ni based activated carbon synergistic catalysts combined with different metals.

PubMed

Cheng, Shouyun; Wei, Lin; Zhao, Xianhui; Kadis, Ethan; Cao, Yuhe; Julson, James; Gu, Zhengrong

2016-06-25

Bio-oil can be upgraded through hydrodeoxygenation (HDO). Low-cost and effective catalysts are crucial for the HDO process. In this study, four inexpensive combinations of Ni based activated carbon synergistic catalysts including Ni/AC, Ni-Fe/AC, Ni-Mo/AC and Ni-Cu/AC were evaluated for HDO of prairie cordgrass (PCG) bio-oil. The tests were carried out in the autoclave under mild operating conditions with 500psig of H2 pressure and 350°C temperature. The catalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscope (TEM). The results show that all synergistic catalysts had significant improvements on the physicochemical properties (water content, pH, oxygen content, higher heating value and chemical compositions) of the upgraded PCG bio-oil. The higher heating value of the upgraded bio-oil (ranging from 29.65MJ/kg to 31.61MJ/kg) improved significantly in comparison with the raw bio-oil (11.33MJ/kg), while the oxygen content reduced to only 21.70-25.88% from 68.81% of the raw bio-oil. Compared to raw bio-oil (8.78% hydrocarbons and no alkyl-phenols), the Ni/AC catalysts produced the highest content of gasoline range hydrocarbons (C6-C12) at 32.63% in the upgraded bio-oil, while Ni-Mo/AC generated the upgraded bio-oil with the highest content of gasoline blending alkyl-phenols at 38.41%. Copyright © 2016 Elsevier B.V. All rights reserved.

A complete two-phase model of a porous cathode of a PEM fuel cell

NASA Astrophysics Data System (ADS)

Hwang, J. J.

This paper has developed a complete two-phase model of a proton exchange membrane (PEM) fuel cell by considering fluid flow, heat transfer and current simultaneously. In fluid flow, two momentum equations governing separately the gaseous-mixture velocity (u g) and the liquid-water velocity (u w) illustrate the behaviors of the two-phase flow in a porous electrode. Correlations for the capillary pressure and the saturation level connect the above two-fluid transports. In heat transfer, a local thermal non-equilibrium (LTNE) model accounting for intrinsic heat transfer between the reactant fluids and the solid matrices depicts the interactions between the reactant-fluid temperature (T f) and the solid-matrix temperature (T s). The irreversibility heating due to electrochemical reactions, Joule heating arising from Ohmic resistance, and latent heat of water condensation/evaporation are considered in the present non-isothermal model. In current, Ohm's law is applied to yield the conservations in ionic current (i m) and electronic current (i s) in the catalyst layer. The Butler-Volmer correlation describes the relation of the potential difference (overpotential) and the transfer current between the electrolyte (such as Nafion™) and the catalyst (such as Pt/C).

The effect of pulsed electric fields on carotenoids bioaccessibility: The role of tomato matrix.

PubMed

Bot, Francesca; Verkerk, Ruud; Mastwijk, Hennie; Anese, Monica; Fogliano, Vincenzo; Capuano, Edoardo

2018-02-01

Tomato fractions were subjected to pulsed electric fields treatment combined or not with heating. Results showed that pulsed electric fields and heating applied in combination or individually induced permeabilization of cell membranes in the tomato fractions. However, no changes in β-carotene and lycopene bioaccessibility were found upon combined and individual pulsed electric fields and heating, except in the following cases: (i) in tissue, a significant decrease in lycopene bioaccessibility upon combined pulsed electric fields and heating and heating only was observed; (ii) in chromoplasts, both β-carotene and lycopene bioaccessibility significantly decreased upon combined pulsed electric fields and heating and pulsed electric fields only. The reduction in carotenoids bioaccessibility was attributed to modification in chromoplasts membrane and carotenoids-protein complexes. Differences in the effects of pulsed electric fields on bioaccessibility among different tomato fractions were related to tomato structure complexity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ash reduction system using electrically heated particulate matter filter

DOEpatents

Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J; He, Yongsheng [Sterling Heights, MI

2011-08-16

A control system for reducing ash comprises a temperature estimator module that estimates a temperature of an electrically heated particulate matter (PM) filter. A temperature and position estimator module estimates a position and temperature of an oxidation wave within the electrically heated PM filter. An ash reduction control module adjusts at least one of exhaust flow, fuel and oxygen levels in the electrically heated PM filter to adjust a position of the oxidation wave within the electrically heated PM filter based on the oxidation wave temperature and position.

Dynamics of ultrathin V-oxide layers on Rh(111) in catalytic oxidation of ammonia and CO.

PubMed

von Boehn, B; Preiss, A; Imbihl, R

2016-07-20

Catalytic oxidation of ammonia and CO has been studied in the 10(-4) mbar range using a catalyst prepared by depositing ultra-thin vanadium oxide layers on Rh(111) (θV ≈ 0.2 MLE). Using photoemission electron microscopy (PEEM) as a spatially resolving method, we observe that upon heating in an atmosphere of NH3 and O2 the spatial homogeneity of the VOx layer is removed at 800 K and a pattern consisting of macroscopic stripes develops; at elevated temperatures this pattern transforms into a pattern of circular VOx islands. Under reaction conditions the neighboring VOx islands become attracted by each other and coalesce. Similar processes of pattern formation and island coalescence are observed in catalytic CO oxidation. Reoxidation of the reduced VOx catalyst proceeds via surface diffusion of oxygen adsorbed onto Rh(111). A pattern consisting of macroscopic circular VOx islands can also be obtained by heating a Rh(111)/VOx catalyst in pure O2.

Catalytic and atmospheric effects on microwave pyrolysis of corn stover.

PubMed

Huang, Yu-Fong; Kuan, Wen-Hui; Chang, Chi-Cheng; Tzou, Yu-Min

2013-03-01

Corn stover, which is one of the most abundant agricultural residues around the world, could be converted into valuable biofuels and bio based products by means of microwave pyrolysis. After the reaction at the microwave power level of 500W for the processing time of 30min, the reaction performance under N2 atmosphere was generally better than under CO2 atmosphere. This may be due to the better heat absorbability of CO2 molecules to reduce the heat for stover pyrolysis. Most of the metal-oxide catalysts effectively increased the maximum temperature and mass reduction ratio but lowered the calorific values of solid residues. The gas most produced was CO under N2 atmosphere but CO2 under CO2 atmosphere. Catalyst addition lowered the formation of PAHs and thus made liquid products less toxic. More liquid products and less gas products were generated when using the catalysts possibly due to the existence of the Fischer-Tropsch synthesis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preparation of supported electrocatalyst comprising multiwalled carbon nanotubes

DOEpatents

Wu, Gang; Zelenay, Piotr

2013-08-27

A process for preparing a durable non-precious metal oxygen reduction electrocatalyst involves heat treatment of a ball-milled mixture of polyaniline and multiwalled carbon nanotubes in the presence of a Fe species. The catalyst is more durable than catalysts that use carbon black supports. Performance degradation was minimal or absent after 500 hours of operation at constant cell voltage of 0.40 V.

Catalyst evaluation for oxygen reduction reaction in concentrated phosphoric acid at elevated temperatures

NASA Astrophysics Data System (ADS)

Hu, Yang; Jiang, Yiliang; Jensen, Jens Oluf; Cleemann, Lars N.; Li, Qingfeng

2018-01-01

Phosphoric acid is the common electrolyte for high-temperature polymer electrolyte fuel cells (HT-PEMFCs) that have advantages such as enhanced CO tolerance and simplified heat and water management. The currently used rotating disk electrode technique is limited to tests in dilute solutions at low temperatures and hence is not suitable for catalyst evaluation for HT-PEMFCs. In this study, we have designed and constructed a half-cell setup to measure the intrinsic activities of catalysts towards the oxygen reduction reaction (ORR) in conditions close to HT-PEMFC cathodes. By optimization of the hydrophobic characteristics of electrodes and the catalyst layer thickness, ORR activities of typical Pt/C catalysts are successfully measured in concentrated phosphoric acid at temperatures above 100 °C. In terms of mass-specific activities, the catalyst exhibits about two times higher activity in the half-cell electrode than that observed in fuel cells, indicating the feasibility of the technique as well as the potential for further improvement of fuel cell electrode performance.

Anchored nanostructure materials and method of fabrication

DOEpatents

Seals, Roland D; Menchhofer, Paul A; Howe, Jane Y; Wang, Wei

2012-11-27

Anchored nanostructure materials and methods for their fabrication are described. The anchored nanostructure materials may utilize nano-catalysts that include powder-based or solid-based support materials. The support material may comprise metal, such as NiAl, ceramic, a cermet, or silicon or other metalloid. Typically, nanoparticles are disposed adjacent a surface of the support material. Nanostructures may be formed as anchored to nanoparticles that are adjacent the surface of the support material by heating the nano-catalysts and then exposing the nano-catalysts to an organic vapor. The nanostructures are typically single wall or multi-wall carbon nanotubes.

Resin catalysts and method of preparation

DOEpatents

Smith, Jr., Lawrence A.

1986-01-01

Heat stabilized catalyst compositions are prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

Resin catalysts and method of preparation

DOEpatents

Smith, L.A. Jr.

1986-12-16

Heat stabilized catalyst compositions are prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

Biomass-derived high-performance tungsten-based electrocatalysts on graphene for hydrogen evolution

DOE PAGES

Meng, Fanke; Hu, Enyuan; Zhang, Lihua; ...

2015-08-05

We report a new class of highly active and stable tungsten-based catalysts to replace noble metal materials for the hydrogen evolution reaction (HER) in an acidic electrolyte. The catalyst is produced by heating an earth-abundant and low-cost mixture of ammonium tungstate, soybean powder and graphene nanoplatelets (WSoyGnP). The catalyst compound consists of tungsten carbide (W₂C and WC) and tungsten nitride (WN) nanoparticles decorated on graphene nanoplatelets. The catalyst demonstrates an overpotential (η₁₀, the potential at a current density of 10 mA cm⁻²) of 0.105 V, which is the smallest among tungsten-based HER catalysts in acidic media. The coupling with graphenemore » significantly reduces the charge transfer resistance and increases the active surface area of the product, which are favorable for enhancing the HER activity. Therefore, the approach of employing biomass and other less expensive materials as precursors for the production of catalysts with high HER activity provides a new path for the design and development of efficient catalysts for the hydrogen production industry.« less

Nanostructured material-based biofuel cells: recent advances and future prospects.

PubMed

Zhao, Cui-E; Gai, Panpan; Song, Rongbin; Chen, Ying; Zhang, Jianrong; Zhu, Jun-Jie

2017-03-06

During the past decade, biofuel cells (BFCs) have emerged as an emerging technology on account of their ability to directly generate electricity from biologically renewable catalysts and fuels. Due to the boost in nanotechnology, significant advances have been accomplished in BFCs. Although it is still challenging to promote the performance of BFCs, adopting nanostructured materials for BFC construction has been extensively proposed as an effective and promising strategy to achieve high energy production. In this review, we presented the major novel nanostructured materials applied for BFCs and highlighted the breakthroughs in this field. Based on different natures of the bio-catalysts and electron transfer process at the bio-electrode surfaces, the fundamentals of BFC systems, including enzymatic biofuel cells (EBFCs) and microbial fuel cells (MFCs), have been elucidated. In particular, the principle of electrode materials design has been detailed in terms of enhancing electrical communications between biological catalysts and electrodes. Furthermore, we have provided the applications of BFCs and potential challenges of this technology.

High density Polyethylene plastic waste treatment with microwave heating pyrolysis method using coconut-shell activated carbon to produce alternative fuels

NASA Astrophysics Data System (ADS)

Juliastuti, S. R.; Hisbullah, M. I.; Abdillah, M.

2018-03-01

Pyrolysis is a technology that could crack polimer such as plastic waste into alternative fuels. This research uses microwave heating methode, which more efficient than conventional heating methode. The plastic waste used is 200 grams of HDPE, with feed to catalyst weight ratio are 1:1, 0.6:1, 0.4:1. Pyrolysis was run at temperatures of 250, 300, 350, & 400 °C for 15, 30 and 45 min. From the experimental result, the best variable of pyrolysis process with microwave method is at 45 minutes, at 400°C, and 1:1 feed to catalyst weight ratio. Result shows that yield of liquid and gas product is 99.22%; yield of residue is 0.78%; value of liquid product’s composition (cycloparaffin and n-paraffin) is 54.09% and concentration of methane gas is 10.2%.

International Assessment of Carbon Nanotube Manufacturing and Applications

DTIC Science & Technology

2007-06-01

oriented and long SWNT arrays obtained by the “fast-heating” growth process (Huang et al . 2004); the Fe/Mo catalyst nanoparticles are deposited ...and Cu layers for top-layer electrical contact. More recent work has been with gas-phase- deposited Ni and Co nanoparticles as catalysts (Sato et al ...22 3.6 Microstructure of MWCNT materials produced by a continuous process at Nano Carbon technologies

Ultrahigh figure-of-merit for hydrogen generation from sodium borohydride using ternary metal catalysts

NASA Astrophysics Data System (ADS)

Hu, Lunghao; Ceccato, R.; Raj, R.

We report further increase in the figure-of-merit (FOM) for hydrogen generation from NaBH 4 than reported in an earlier paper [1], where a sub-nanometer layer of metal catalysts are deposited on carbon nanotube paper (CNT paper) that has been functionalized with polymer-derived silicon carbonitride (SiCN) ceramic film. Ternary, Ru-Pd-Pt, instead of the binary Pd-Pt catalyst used earlier, together with a thinner CNT paper is shown to increase the figure-of-merit by up to a factor of six, putting is above any other known catalyst for hydrogen generation from NaBH 4. The catalysts are prepared by first impregnating the functionalized CNT-paper with solutions of the metal salts, followed by reduction in a sodium borohydride solution. The reaction mechanism and the catalyst efficiency are described in terms of an electric charge transfer, whereby the negative charge on the BH 4 - ion is exchanged with hydrogen via the electronically conducting SiCN/CNT substrate [1].

Method of making MEA for PEM/SPE fuel cell

DOEpatents

Hulett, Jay S.

2000-01-01

A method of making a membrane-electrode-assembly (MEA) for a PEM/SPE fuel cell comprising applying a slurry of electrode-forming material directly onto a membrane-electrolyte film. The slurry comprises a liquid vehicle carrying catalyst particles and a binder for the catalyst particles. The membrane-electrolyte is preswollen by contact with the vehicle before the electrode-forming slurry is applied to the membrane-electrolyte. The swollen membrane-electrolyte is constrained against shrinking in the "x" and "y" directions during drying. Following assembly of the fuel cell, the MEA is rehydrated inside the fuel cell such that it swells in the "z" direction for enhanced electrical contact with contiguous electrically conductive components of the fuel cell.

Residential Photovoltaic/Thermal Energy System

NASA Technical Reports Server (NTRS)

Selcuk, M. K.

1987-01-01

Proposed system supplies house with both heat and electricity. Pair of reports describes concept for self-sufficient heating, cooling, and power-generating system for house. Panels on walls of house provide hot water, space heating, and heat to charge heat-storage system, and generate electricity for circulation pumps and fans. Roof panels generate electricity for household, operate heat pump for summer cooling, and provide supplementary winter heating via heat pump, using solar-cell cooling-fluid loop. Wall and roof panels used independently.

Catalyst- and Reagent-free Electrochemical Azole C-H Amination.

PubMed

Qiu, Youai; Struwe, Julia; Meyer, Tjark H; Oliveira, Joao Carlos Agostinho Carlos Agostinho; Ackermann, Lutz

2018-06-14

Catalyst-, and chemical oxidant-free electrochemical azole C-H aminations were accomplished via cross-dehydrogenative C-H/N-H functionalization. The catalyst-free electrochemical C-H amination proved feasible on azoles with high levels of efficacy and selectivity, avoiding the use of stoichiometric oxidants under ambient conditions. Likewise, the C(sp3)-H nitrogenation proved viable under otherwise identical conditions. The dehydrogenative C-H amination featured ample scope, including cyclic and acyclic aliphatic amines as well as anilines, and employed sustainable electricity as the sole oxidant. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method and apparatus for obtaining enhanced production rate of thermal chemical reactions

DOEpatents

Tonkovich, Anna Lee Y.; Wang, Yong; Wegeng, Robert S.; Gao, Yufei

2003-09-09

Reactors and processes are disclosed that can utilize high heat fluxes to obtain fast, steady-state reaction rates. Porous catalysts used in conjunction with microchannel reactors to obtain high rates of heat transfer are also disclosed. Reactors and processes that utilize short contact times, high heat flux and low pressure drop are described. Improved methods of steam reforming are also provided.

Method and apparatus for obtaining enhanced production rate of thermal chemical reactions

DOEpatents

Tonkovich, Anna Lee Y [Pasco, WA; Wang, Yong [Richland, WA; Wegeng, Robert S [Richland, WA; Gao, Yufei [Kennewick, WA

2006-05-16

Reactors and processes are disclosed that can utilize high heat fluxes to obtain fast, steady-state reaction rates. Porous catalysts used in conjunction with microchannel reactors to obtain high rates of heat transfer are also disclosed. Reactors and processes that utilize short contact times, high heat flux and low pressure drop are described. Improved methods of steam reforming are also provided.

Electrical initiation of an energetic nanolaminate film

DOEpatents

Tringe, Joseph W.; Gash, Alexander E.; Barbee, Jr., Troy W.

2010-03-30

A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.

Electric home heating: Substitution for oil and gas

NASA Astrophysics Data System (ADS)

Burwell, C. C.; Devine, W. D., Jr.; Phung, D. L.

1982-03-01

The objective of the research is to determine the potential for substituting electricity generated with surplus coal and nuclear capacity for gas and oil used for home heating. The relative effectiveness of electric heating was determined by an analysis of the purposes of extra winter sales of electricity to the residential sector compared to a similar analysis for extra winter sales of natural gas. The price of electricity for heating is determined based on utility rate structures for selected utilities (primarily located in the north and south central portions of the country) having surplus coal and nuclear capacity throughout the decade of the 1980s. It is found that, on the average, the overall efficiency of fuel use for heating homes electrically is comparable to the use of combustion systems in the home and that electric heating is substantially less costly than direct heating with oil in regions where coal and uranium are the primary fuels used for power generation.

Acidity, oxophilicity and hydrogen sticking probability of supported metal catalysts for hydrodeoxygenation process

NASA Astrophysics Data System (ADS)

Lup, A. Ng K.; Abnisa, F.; Daud, W. M. A. W.; Aroua, M. K.

2018-03-01

Hydrodeoxygenation is an oxygen removal process that occurs in the presence of hydrogen and catalysts. This study has shown the importance of acidity, oxophilicity and hydrogen sticking probability of supported metal catalysts in having high hydrodeoxygenation activity and selectivity. These properties are required to ensure the catalyst has high affinity for C-O or C=O bonds and the capability for the adsorption and activation of H2 and O-containing compounds. A theoretical framework of temperature programmed desorption technique was also discussed for the quantitative understanding of these properties. By using NH3-TPD, the nature and abundance of acid sites of catalyst can be determined. By using H2-TPD, the nature and abundance of metallic sites can also be determined. The desorption activation energy could also be determined based on the Redhead analysis of TPD spectra with different heating rates.

Activating catalysts with mechanical force.

PubMed

Piermattei, Alessio; Karthikeyan, S; Sijbesma, Rint P

2009-05-01

Homogeneously catalysed reactions can be 'switched on' by activating latent catalysts. Usually, activation is brought about by heat or an external chemical agent. However, activation of homogeneous catalysts with a mechanical trigger has not been demonstrated. Here, we introduce a general method to activate latent catalysts by mechanically breaking bonds between a metal and one of its ligands. We have found that silver(I) complexes of polymer-functionalized N-heterocyclic carbenes, which are latent organocatalysts, catalyse a transesterification reaction when exposed to ultrasound in solution. Furthermore, ultrasonic activation of a ruthenium biscarbene complex with appended polymer chains results in catalysis of olefin metathesis reactions. In each case, the catalytic activity results from ligand dissociation, brought about by transfer of mechanical forces from the polymeric substituents to the coordination bond. Mechanochemical catalyst activation has potential applications in transduction and amplification of mechanical signals, and mechanically initiated polymerizations hold promise as a novel repair mechanism in self-healing materials.

Repeatable hydrogen generation of 3D microporous nickel membrane using chemical milling

NASA Astrophysics Data System (ADS)

Seo, Keumyoung; Lim, Taekyung; Ju, Sanghyun

2018-05-01

In this study, we investigated a novel method of hydrogen generation through a chemical milling process. In the process of generating hydrogen with a thermochemical water-splitting method using a 3D microporous nickel membrane, the nickel surface is oxidized, leading to a decreased generation of hydrogen gas with time. To regenerate hydrogen from the oxidized catalysts, the oxidized metal surface was easily removed at room temperature, re-exposing a metal surface with abundant oxygen vacancies for continuous hydrogen generation. With this method, ~110 µmol · g‑1 of hydrogen gas was continuously produced per cycle. Since this method enabled us to create a fit state for hydrogen generation without extra heat, light, or electrical energy, it can solve the biggest commercialization challenge: inefficiency because the energy required for hydrogen generation is higher than the energy of the generated hydrogen.

Gas concentration cells for utilizing energy

DOEpatents

Salomon, R.E.

1987-06-30

An apparatus and method are disclosed for utilizing energy, in which the apparatus may be used for generating electricity or as a heat pump. When used as an electrical generator, two gas concentration cells are connected in a closed gas circuit. The first gas concentration cell is heated and generates electricity. The second gas concentration cell repressurizes the gas which travels between the cells. The electrical energy which is generated by the first cell drives the second cell as well as an electrical load. When used as a heat pump, two gas concentration cells are connected in a closed gas circuit. The first cell is supplied with electrical energy from a direct current source and releases heat. The second cell absorbs heat. The apparatus has no moving parts and thus approximates a heat engine. 4 figs.

Gas concentration cells for utilizing energy

DOEpatents

Salomon, Robert E.

1987-01-01

An apparatus and method for utilizing energy, in which the apparatus may be used for generating electricity or as a heat pump. When used as an electrical generator, two gas concentration cells are connected in a closed gas circuit. The first gas concentration cell is heated and generates electricity. The second gas concentration cell repressurizes the gas which travels between the cells. The electrical energy which is generated by the first cell drives the second cell as well as an electrical load. When used as a heat pump, two gas concentration cells are connected in a closed gas circuit. The first cell is supplied with electrical energy from a direct current source and releases heat. The second cell absorbs heat. The apparatus has no moving parts and thus approximates a heat engine.

Priestley's Shadow and Lavoisier's Influence: Electricity and Heat in the Late Eighteenth and Early Nineteenth Centuries

NASA Astrophysics Data System (ADS)

Fisher, Amy

In the late eighteenth century, Joseph Priestley argued that any complete theory of heat also had to explain electrical phenomena, which manifested many similar effects to heat. For example, sparking or heating a sample of trapped air caused a reduction in the volume of air and made the gas toxic to living organisms. Because of the complexity of electrical and thermal phenomena, Antoine Lavoisier did not address electrical action in his published works. Rather, he focused on those effects produced by heating alone. With the success of Lavoisier's caloric theory of heat, natural philosophers and chemists continued to debate the relationship between heat and electricity. In this presentation, I compare and contrast the fate of caloric in early-nineteenth-century electrical studies via the work of two scientists: Humphry Davy in Britain and Robert Hare in America.

Novel synthesis of highly durable and active Pt catalyst encapsulated in nitrogen containing carbon for polymer electrolyte membrane fuel cell

NASA Astrophysics Data System (ADS)

Lee, Hyunjoon; Sung, Yung-Eun; Choi, Insoo; Lim, Taeho; Kwon, Oh Joong

2017-09-01

Novel synthesis of a Pt catalyst encapsulated in a N-containing carbon layer for use in a polymer electrolyte membrane fuel cell is described in this study. A Pt-aniline complex, formed by mixing Pt precursor and aniline monomer, was used as the source of Pt, C, and N. Heat treatment of the Pt-aniline complex with carbon black yielded 5 nm Pt nanoparticles encapsulated by a N-containing carbon layer originating from aniline carbonization. The synthesized Pt catalyst exhibited higher mass specific activity to oxygen reduction reaction than that shown by conventional Pt/C catalyst because pyridinic N with graphitic carbon in the carbon layer provided active sites for oxygen reduction reaction in addition to those provided by Pt. In single cell testing, initial performance of the synthesized catalyst was limited because the thick catalyst layer increased resistance related to mass transfer. However, it was observed that the carbon layer successfully prevented Pt nanoparticles from growing via agglomeration and Ostwald ripening under fuel cell operation, thereby improving durability. Furthermore, a mass specific performance of the synthesized catalyst higher than that of a conventional Pt/C catalyst was achieved by modifying the synthesized catalyst's layer thickness.

Combined goal gasifier and fuel cell system and method

DOEpatents

Gmeindl, Frank D.; Geisbrecht, Rodney A.

1990-01-01

A molten carbonate fuel cell is combined with a catalytic coal or coal char gasifier for providing the reactant gases comprising hydrogen, carbon monoxide and carbon dioxide used in the operation of the fuel cell. These reactant gases are stripped of sulfur compounds and particulate material and are then separated in discrete gas streams for conveyance to appropriate electrodes in the fuel cell. The gasifier is arranged to receive the reaction products generated at the anode of the fuel cell by the electricity-producing electrochemical reaction therein. These reaction products from the anode are formed primarily of high temperature steam and carbon dioxide to provide the steam, the atmosphere and the heat necessary to endothermically pyrolyze the coal or char in the presence of a catalyst. The reaction products generated at the cathode are substantially formed of carbon dioxide which is used to heat air being admixed with the carbon dioxide stream from the gasifier for providing the oxygen required for the reaction in the fuel cell and for driving an expansion device for energy recovery. A portion of this carbon dioxide from the cathode may be recycled into the fuel cell with the air-carbon dioxide mixture.

Epidermal changes in heat and electrically injured pig skin: a light microscopic study of the sequences in morphology.

PubMed

Thomsen, H K; Danielsen, L; Nielsen, O; Aalund, O; Nielsen, K G; Karlsmark, T; Genefke, I K

1982-09-01

Biopsies were obtained from heat and electrically exposed pig skin at different at different times after exposure, in order to describe the morphological sequences in heat and electrically injured skin. The work is part of a series of studies in which it is investigated whether morphological methods can be used in disclosing electrical torture. Epidermal changes in heat lesions differed from those of electrical lesions in all experiments. Heat lesions typically showed a detached epidermis with fibrillar or granular cytoplasm. In older lesions the epidermis appeared concrete. Electrical lesions showed an attached epidermis with small defects, a white, homogeneous cytoplasm, vesicular nuclei and curled, clumped keratin. The electrical lesions were rejected at day 4 or 5. The number of characteristic morphological changes in epidermis decreased with the age of the lesions. It is concluded that epidermal electrical lesions differ in morphology from heat lesions and that it is possible to evaluate the age of the lesions.

Microcombustor-thermoelectric power generator for 10-50 watt applications

NASA Astrophysics Data System (ADS)

Marshall, Daniel S.; Cho, Steve T.

2010-04-01

Fuel-based portable power systems, including combustion and fuel cell systems, take advantage of the 80x higher energy density of fuel over lithium battery technologies and offer the potential for much higher energy density power sources - especially for long-duration applications, such as unattended sensors. Miniaturization of fuel-based systems poses significant challenges, including processing of fuel in small channels, catalyst poisoning, and coke and soot formation. Recent advances in micro-miniature combustors in the 200Watt thermal range have enabled the development of small power sources that use the chemical energy of heavy fuel to drive thermal-to-electric converters for portable applications. CUBE Technology has developed compact Micro-Furnace combustors that efficiently deliver high-quality heat to optimized thermal-to-electric power converters, such as advanced thermoelectric power modules and Stirling motors, for portable power generation at the 10-50Watt scale. Key innovations include a compact gas-gas recuperator, innovative heavy fuel processing, coke- & soot-free operation, and combustor optimization for low balance-of-plant power use while operating at full throttle. This combustor enables the development of robust, high energy density, miniature power sources for portable applications.

Turnkey Heating, Ventilating, and Air Conditioning and Lighting Retrofit Solution Combining Energy Efficiency and Demand Response Benefits

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

Doebber, Ian; Deru, Michael; Trenbath, Kim

NREL worked with the Bonneville Power Administration's Technology Innovation Office to demonstrate a turnkey, retrofit technology that combines demand response (DR) and energy efficiency (EE) benefits for HVAC and lighting in retail buildings. As a secondary benefit, we also controlled various plug loads and electric hot water heaters (EHWH). The technology demonstrated was Transformative Wave's eIQ Building Management System (BMS) automatically responding to DR signals. The BMS controlled the HVAC rooftop units (RTU) using the CATALYST retrofit solution also developed by Transformative Wave. The non-HVAC loads were controlled using both hardwired and ZigBee wireless communication. The wireless controllers, manufactured bymore » Autani, were used when the building's electrical layout was too disorganized to leverage less expensive hardwired control. The six demonstration locations are within the Seattle metro area. Based on the assets curtailed by the BMS at each location, we projected the DR resource. We were targeting a 1.7 W/ft2 shed for the summer Day-Ahead events and a 0.7 W/ft2 shed for the winter events. While summarized in Table ES-1, only one summer DR event was conducted at Casino #2.« less

Induction heaters used to heat subsurface formations

DOEpatents

Nguyen, Scott Vinh [Houston, TX; Bass, Ronald M [Houston, TX

2012-04-24

A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300.degree. C.

Electrospun TiO2 nanofibers incorporated with graphene nanoflakes for energy conversion

NASA Astrophysics Data System (ADS)

Shinde, Manish A.; Alarifi, Ibrahim; Alharbi, Abdulaziz; Asmatulu, Ramazan

2015-03-01

Solar energy has been used in many different ways, including solar water heater, solar cooking, space heating, and electricity generation. The major drawbacks of the solar energy conversion systems are the lower conversion efficiency and higher manufacturing and replacement costs. In order to eliminate these obstacles, many studies were focused on the energy and cost efficiencies of the solar cells (particularly dye sensitized solar cells - DSSC and thin film solar cells). In the present study, TiO2 nanofibers incorporated with graphene nanoflakes (0, 2, 4, and 8wt.%) were produced using electrospinning process. The chemical utilized for the electrospinning process included poly (vinyle acetate), dimetylfomamide (DMF), titanium (IV) isopropoxide and acetic acid in the presence and absence of graphene nanoflakes. The resultant nanofibers were heat treated at 300 °C for 2 hrs in a standard oven to remove all the organic parts of the nanofibers, and then further heated up to 500 °C in an argon atmosphere for additional 12 hrs to crystalline the nanofibers. SEM, TEM and XRD studies showed that graphene and TiO2 nanofibers are well integrated in the nanofiber structures. This study may guide some of the scientists and engineers to tailor the energy bang gap structures of some of the semiconductor materials for different industrial applications, including DSSC, water splitting, catalyst, batteries, and fuel cell.

Nano-structured manganese oxide as a cathodic catalyst for enhanced oxygen reduction in a microbial fuel cell fed with a synthetic wastewater.

PubMed

Liu, Xian-Wei; Sun, Xue-Fei; Huang, Yu-Xi; Sheng, Guo-Ping; Zhou, Kang; Zeng, Raymond J; Dong, Fang; Wang, Shu-Guang; Xu, An-Wu; Tong, Zhong-Hua; Yu, Han-Qing

2010-10-01

Microbial fuel cells (MFCs) provide new opportunities for the simultaneous wastewater treatment and electricity generation. Enhanced oxygen reduction capacity of cost-effective metal-based catalysts in an air cathode is essential for the scale-up and commercialization of MFCs in the field of wastewater treatment. We demonstrated that a nano-structured MnO(x) material, prepared by an electrochemically deposition method, could be an effective catalyst for oxygen reduction in an MFC to generate electricity with the maximum power density of 772.8 mW/m(3) and remove organics when the MFC was fed with an acetate-laden synthetic wastewater. The nano-structured MnO(x) with the controllable size and morphology could be readily obtained with the electrochemical deposition method. Both morphology and manganese oxidation state of the nano-scale catalyst were largely dependent on the electrochemical preparation process, and they governed its catalytic activity and the cathodic oxygen reduction performance of the MFC accordingly. Furthermore, cyclic voltammetry (CV) performed on each nano-structured material suggests that the MnO(x) nanorods had an electrochemical activity towards oxygen reduction reaction via a four-electron pathway in a neutral pH solution. This work provides useful information on the facile preparation of cost-effective cathodic catalysts in a controllable way for the single-chamber air-cathode MFC for wastewater treatment. Copyright © 2010 Elsevier Ltd. All rights reserved.

5. PHOTOGRAPHIC COPY OF ORIGINAL DRAWINGS, ELECTRIC AIR AND HEATING ...

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

5. PHOTOGRAPHIC COPY OF ORIGINAL DRAWINGS, ELECTRIC AIR AND HEATING UNIT, PLAN AND ELEVATION - Wyoming Air National Guard Base, Electric, Air & Heating Plant, Cheyenne Airport, Cheyenne, Laramie County, WY

Trimerization of aromatic nitriles

NASA Technical Reports Server (NTRS)

Hsu, L. C. (Inventor)

1977-01-01

Triazine compounds and cross-linked polymer compositions were made by heating aromatic nitriles to a temperature in the range of about 100 C to about 700 C, in the presence of a catalyst or mixture of catalysts. Aromatic nitrile-modified (terminated and/or appended) imide, benzimidazole, imidazopyrrolone, quinoxaline, and other condensation type prepolymers or their precopolymers were made which were trimerized with or without a filler by the aforementioned catalytic trimerization process.

Hydrodesulfurization and hydrodenitrogenation catalysts obtained from coal mineral matter

DOEpatents

Liu, Kindtoken H. D.; Hamrin, Jr., Charles E.

1982-01-01

A hydrotreating catalyst is prepared from coal mineral matter obtained by low temperature ashing coals of relatively low bassanite content by the steps of: (a) depositing on the low temperature ash 0.25-3 grams of an iron or nickel salt in water per gram of ash and drying a resulting slurry; (b) crushing and sizing a resulting solid; and (c) heating the thus-sized solid powder in hydrogen.

Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

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

Gangwal, Santosh K.; McCabe, Kevin

2015-04-30

The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifiermore » (TRIG TM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H 2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.« less

Catalytic Microtube Rocket Igniter

NASA Technical Reports Server (NTRS)

Schneider, Steven J.; Deans, Matthew C.

2011-01-01

Devices that generate both high energy and high temperature are required to ignite reliably the propellant mixtures in combustion chambers like those present in rockets and other combustion systems. This catalytic microtube rocket igniter generates these conditions with a small, catalysis-based torch. While traditional spark plug systems can require anywhere from 50 W to multiple kW of power in different applications, this system has demonstrated ignition at less than 25 W. Reactants are fed to the igniter from the same tanks that feed the reactants to the rest of the rocket or combustion system. While this specific igniter was originally designed for liquid methane and liquid oxygen rockets, it can be easily operated with gaseous propellants or modified for hydrogen use in commercial combustion devices. For the present cryogenic propellant rocket case, the main propellant tanks liquid oxygen and liquid methane, respectively are regulated and split into different systems for the individual stages of the rocket and igniter. As the catalyst requires a gas phase for reaction, either the stored boil-off of the tanks can be used directly or one stream each of fuel and oxidizer can go through a heat exchanger/vaporizer that turns the liquid propellants into a gaseous form. For commercial applications, where the reactants are stored as gases, the system is simplified. The resulting gas-phase streams of fuel and oxidizer are then further divided for the individual components of the igniter. One stream each of the fuel and oxidizer is introduced to a mixing bottle/apparatus where they are mixed to a fuel-rich composition with an O/F mass-based mixture ratio of under 1.0. This premixed flow then feeds into the catalytic microtube device. The total flow is on the order of 0.01 g/s. The microtube device is composed of a pair of sub-millimeter diameter platinum tubes connected only at the outlet so that the two outlet flows are parallel to each other. The tubes are each approximately 10 cm long and are heated via direct electric resistive heating. This heating brings the gasses to their minimum required ignition temperature, which is lower than the auto-thermal ignition temperature, and causes the onset of both surface and gas phase ignition producing hot temperatures and a highly reacting flame. The combustion products from the catalytic tubes, which are below the melting point of platinum, are injected into the center of another combustion stage, called the primary augmenter. The reactants for this combustion stage come from the same source but the flows of non-premixed methane and oxygen gas are split off to a secondary mixing apparatus and can be mixed in a near-stoichiometric to highly lean mixture ratio. The primary augmenter is a component that has channels venting this mixed gas to impinge on each other in the center of the augmenter, perpendicular to the flow from the catalyst. The total crosssectional area of these channels is on a similar order as that of the catalyst. The augmenter has internal channels that act as a manifold to distribute equally the gas to the inward-venting channels. This stage creates a stable flame kernel as its flows, which are on the order of 0.01 g/s, are ignited by the combustion products of the catalyst. This stage is designed to produce combustion products in the flame kernel that exceed the autothermal ignition temperature of oxygen and methane.

Morphologies, Preparations and Applications of Layered Double Hydroxide Micro-/Nanostructures

PubMed Central

Kuang, Ye; Zhao, Lina; Zhang, Shuai; Zhang, Fazhi; Dong, Mingdong; Xu, Sailong

2010-01-01

Layered double hydroxides (LDHs), also well-known as hydrotalcite-like layered clays, have been widely investigated in the fields of catalysts and catalyst support, anion exchanger, electrical and optical functional materials, flame retardants and nanoadditives. This feature article focuses on the progress in micro-/nanostructured LDHs in terms of morphology, and also on the preparations, applications, and perspectives of the LDHs with different morphologies. PMID:28883378

Steam Reformer With Fibrous Catalytic Combustor

NASA Technical Reports Server (NTRS)

Voecks, Gerald E.

1987-01-01

Proposed steam-reforming reactor derives heat from internal combustion on fibrous catalyst. Supplies of fuel and air to combustor controlled to meet demand for heat for steam-reforming reaction. Enables use of less expensive reactor-tube material by limiting temperature to value safe for material yet not so low as to reduce reactor efficiency.

Calcination of calcium carbonate and blend therefor

DOEpatents

Mallow, William A.; Dziuk, Jr., Jerome J.

1989-01-01

A method for calcination of a calcium carbonate material comprising heating the calcium carbonate material to a temperature and for a time sufficient to calcine the material to the degree desired while in the presence of a catalyst; said catalyst comprising at least one fused salt having the formula MCO.sub.3.CaCO.sub.3.CaO.H.sub.2 O.sub.x, wherein M is an alkali metal and x is 0 to 1 and formed by fusing MCO.sub.3 and CaCO.sub.3 in a molar ratio of about 1:2 to 2:1, and a blend adapted to be heated to CaO comprising a calcium carbonate material and at least one such fused salt.

Methods and apparatus for catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C.; Butner, Robert Scott; Neuenschwander, Gary G.; Zacher, Alan H.; Hart, Todd R.

2012-08-14

Continuous processing of wet biomass feedstock by catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent separation of sulfur contaminants, or combinations thereof. Treatment further includes separating the precipitates out of the wet feedstock, removing sulfur contaminants, or both using a solids separation unit and a sulfur separation unit, respectively. Having removed much of the inorganic wastes and the sulfur that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Electricity Cogenerator from Hydrogen and Biogas

NASA Astrophysics Data System (ADS)

Pinate, W.; Chinnasa, P.; Dangphonthong, D.

2017-09-01

This research studied about electricity cogenerator from Hydrogen and Biogas and the factors that cause that effecting Hydrogen from Aluminium which was a cylindrical feature. By using a catalyst was NaOH and CaO, it was reacted in distilled water with percentage of Aluminium: the catalyst (NaOH and CaO) and brought to mix with Biogas afterwards, that have been led to electricity from generator 1 kilowatt. The research outcomes were concentration of solutions that caused amount and percent of maximum Hydrogen was to at 10 % wt and 64.73 % which rate of flowing of constant gas 0.56 litter/minute as temperature 97 degree Celsius. After that led Hydrogen was mixed by Biogas next, conducted to electricity from generator and levelled the voltage of generator at 220 Volt. There after the measure of electricity current and found electricity charge would be constant at 3.1 Ampere. And rate of Biogas flowing and Hydrogen, the result was the generator used Biogas rate of flowing was highest 9 litter/minute and the lowest 7.5 litter/minute, which had rate of flowing around 8.2 litter/minute. Total Biogas was used around 493.2 litter or about 0.493 m3 and Hydrogen had rate of flowing was highest 2.5 litter/minute.

Simulation of Rocket-Grade Kerosene Flowing in an Electrically Heated Experimental Apparatus

DTIC Science & Technology

2015-07-01

Technical Paper 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE Simulation of Rocket Kerosene Flowing in an Electrically Heated...rocket-grade kerosene (RP-2) flowing in an electrically heated tube is simulated. The model and boundary conditions are selected so as to simulate an...and Astronautics 1 Simulation of Rocket-Grade Kerosene Flowing in an Electrically Heated Experimental Apparatus Ananda Himansu1 and Matthew C

Alternative Sources of Energy - An Introduction to Fuel Cells

USGS Publications Warehouse

Merewether, E.A.

2003-01-01

Fuel cells are important future sources of electrical power and could contribute to a reduction in the amount of petroleum imported by the United States. They are electrochemical devices similar to a battery and consist of a container, an anode, a cathode, catalysts, an intervening electrolyte, and an attached electrical circuit. In most fuel cell systems, hydrogen is supplied to the anode and oxygen to the cathode which results in the production of electricity, water, and heat. Fuel cells are comparatively efficient and reliable, have no moving parts, operate without combustion, and are modular and scale-able. Their size and shape are flexible and adaptable. In operation, they are nearly silent, are relatively safe, and generally do not pollute the environment. During recent years, scientists and engineers have developed and refined technologies relevant to a variety of fuel cells. Types of fuel cells are commonly identified by the composition of their electrolyte, which could be either phosphoric acid, an alkaline solution, a molten carbonate, a solid metal oxide, or a solid polymer membrane. The electrolyte in stationary power plants could be phosphoric acid, molten carbonates, or solid metal oxides. For vehicles and smaller devices, the electrolyte could be an alkaline solution or a solid polymer membrane. For most fuel cell systems, the fuel is hydrogen, which can be extracted by several procedures from many hydrogen-bearing substances, including alcohols, natural gas (mainly methane), gasoline, and water. There are important and perhaps unresolved technical problems associated with using fuel cells to power vehicles. The catalysts required in several systems are expensive metals of the platinum group. Moreover, fuel cells can freeze and not work in cold weather and can be damaged by impacts. Storage tanks for the fuels, particularly hydrogen, must be safe, inexpensive, of a reasonable size, and contain a supply sufficient for a trip of several hundred miles. Additional major problems will be the extensive and costly changes in the national infrastructure to obtain, store, and distribute large amounts of the fuels, and in related manufacturing

Dual membrane hollow fiber fuel cell and method of operating same

NASA Technical Reports Server (NTRS)

Ingham, J. D.; Lawson, D. D. (Inventor)

1978-01-01

A gaseous fuel cell is described which includes a pair of electrodes formed by open-ended, ion-exchange hollow fibers, each having a layer of metal catalyst deposited on the inner surface and large surface area current collectors such as braided metal mesh in contact with the metal catalyst layer. A fuel cell results when the electrodes are immersed in electrolytes and electrically connected. As hydrogen and oxygen flow through the bore of the fibers, oxidation and reduction reactions develop an electrical potential. Since the hollow fiber configuration provides large electrode area per unit volume and intimate contact between fuel and oxidizer at the interface, and due to the low internal resistance of the electrolyte, high power densities can be obtained.

CATALYTIC PROPERTIES OF SEMICONDUCTORS.

DTIC Science & Technology

SEMICONDUCTORS, CATALYSTS), (*CATALYSIS, REACTION KINETICS), (* SODIUM COMPOUNDS, TUNGSTATES), (*GALLIUM ALLOYS, ARSENIC ALLOYS), (*YTTERBIUM...COMPOUNDS, SILICIDES ), (*GERMANIUM, CATALYSIS), INTERNAL CONVERSION, EXCHANGE REACTIONS, HEAT OF ACTIVATION, THERMODYNAMICS, DEUTERIUM, POWDERS, SURFACES, HYDROGEN

Coupling of exothermic and endothermic reactions in oxidative conversion of natural gas into ethylene/olefins over diluted SrO/La{sub 2}O{sub 3}/SA5205 catalyst

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

Choudhary, V.R.; Mulla, S.A.R.

1997-09-01

In the oxidative conversion of natural gas to ethylene/lower olefins over SrO (17.3 wt.%)/La{sub 2}O{sub 3} (17.9 wt.%)/SA5205 catalyst diluted with inert solid particles (inerts/catalyst(w/w) = 2.0) in the presence of limited O{sub 2}, the exothermic oxidative conversion reactions of natural gas are coupled with the endothermic C{sub 2+} hydrocarbon thermal cracking reactions for avoiding hot spot formation and eliminating heat removal problems. Because of this, the process is operated in the most energy-efficient and safe manner. The influence of various process variables (viz. temperature, NG/O{sub 2} and steam/NG ratios in feed, and space velocity) on the conversion of carbonmore » and also of the individual hydrocarbons in natural gas, the selectivity for C{sub 2}-C{sub 4} olefins, and also on the net heat of reactions in the process has been thoroughly investigated. By carrying out the process at 800--850 C in the presence of steam (H{sub 2}O/NG {le} 0.2) and using limited O{sub 2} in the feed (NG/O{sub 2} = 12--18), high selectivity for ethylene (about 60%) or C{sub 2}-C{sub 4} olefins (above 80%) at the carbon conversion (>15%) of practical interest could be achieved at high space velocity ({ge}34,000 cm{sup 3}/g (catalyst) h), requiring no external energy and also without forming coke or tar-like products. The net heat of reactions can be controlled and the process can be made mildly exothermic or even close to thermoneutral by manipulating the O{sub 2} concentration in the feed.« less

Correlating ultrasonic impulse and addition of ZnO promoter with CO2 conversion and methanol selectivity of CuO/ZrO2 catalysts.

PubMed

Ezeh, Collins I; Yang, Xiaogang; He, Jun; Snape, Colin; Cheng, Xiao Min

2018-04-01

The thermal characteristics of Cu-based catalysts for CO 2 utilization towards the synthesis of methanol were analysed and discussed in this study. The preparation process were varied by adopting ultrasonic irradiation at various impulses for the co-precipitation route and also, by introducing ZnO promoters using the solid-state reaction route. Prepared catalysts were characterised using XRD, TPR, TPD, SEM, BET and TG-DTA-DSC. In addition, the CO 2 conversion and CH 3 OH selectivity of these samples were assessed. Calcination of the catalysts facilitated the interaction of the Cu catalyst with the respective support bolstering the thermal stability of the catalysts. The characterisation analysis clearly reveals that the thermal performance of the catalysts was directly related to the sonication impulse and heating rate. Surface morphology and chemistry was enhanced with the aid of sonication and introduction of promoters. However, the impact of the promoter outweighs that of the sonication process. CO 2 conversion and methanol selectivity showed a significant improvement with a 270% increase in methanol yield. Copyright © 2017 Elsevier B.V. All rights reserved.

Reticulation of Aqueous Polyurethane Systems Controlled by DSC Method

PubMed Central

Cakic, Suzana; Lacnjevac, Caslav; Rajkovic, Milos B.; Raskovic, Ljiljana; Stamenkovic, Jakov

2006-01-01

The DSC method has been employed to monitor the kinetics of reticulation of aqueous polyurethane systems without catalysts, and with the commercial catalyst of zirconium (CAT®XC-6212) and the highly selective manganese catalyst, the complex Mn(III)-diacetylacetonemaleinate (MAM). Among the polyol components, the acrylic emulsions were used for reticulation in this research, and as suitable reticulation agents the water emulsible aliphatic polyisocyanates based on hexamethylendoisocyanate with the different contents of NCO-groups were employed. On the basis of DSC analysis, applying the methods of Kissinger, Freeman-Carroll and Crane-Ellerstein the pseudo kinetic parameters of the reticulation reaction of aqueous systems were determined. The temperature of the examination ranged from 50°C to 450°C with the heat rate of 0.5°C/min. The reduction of the activation energy and the increase of the standard deviation indicate the catalytic action of the selective catalysts of zirconium and manganese. The impact of the catalysts on the reduction of the activation energy is the strongest when using the catalysts of manganese and applying all the three afore-said methods. The least aberrations among the stated methods in defining the kinetic parameters were obtained by using the manganese catalyst.

Study on the NO removal efficiency of the lignite pyrolysis coke catalyst by selective catalytic oxidation method

PubMed Central

Wen, Xin; Ma, Zhenhua; Zhang, Lei; Sha, Xiangling; He, Huibin; Zeng, Tianyou; Wang, Yusu; Chen, Jihao

2017-01-01

Selective catalytic oxidation (SCO) method is commonly used in wet denitration technology; NO after the catalytic oxidation can be removed with SO2 together by wet method. Among the SCO denitration catalysts, pyrolysis coke is favored by the advantages of low cost and high catalytic activity. In this paper, SCO method combined with pyrolysis coke catalyst was used to remove NO from flue gas. The effects of different SCO operating conditions and different pyrolysis coke catalyst made under different process conditions were studied. Besides, the specific surface area of the catalyst and functional groups were analyzed with surface area analyzer and Beohm titration. The results are: (1) The optimum operating conditions of SCO is as follows: the reaction temperature is 150°C and the oxygen content is 6%. (2) The optimum pyrolysis coke catalyst preparation processes are as follows: the pyrolysis final temperature is 750°C, and the heating rate is 44°C / min. (3) The characterization analysis can be obtained: In the denitration reaction, the basic functional groups and the phenolic hydroxyl groups of the catalyst play a major role while the specific surface area not. PMID:28793346

Synthesis of platinum nanoparticle electrocatalysts by atomic layer deposition

NASA Astrophysics Data System (ADS)

Lubers, Alia Marie

Demand for energy continues to increase, and without alternatives to fossil fuel combustion the effects on our environment will become increasingly severe. Fuel cells offer a promising improvement on current methods of energy generation; they are able to convert hydrogen fuel into electricity with a theoretical efficiency of up to 83% and interface smoothly with renewable hydrogen production. Fuel cells can replace internal combustion engines in vehicles and are used in stationary applications to power homes and businesses. The efficiency of a fuel cell is maximized by its catalyst, which is often composed of platinum nanoparticles supported on carbon. Economical production of fuel cell catalysts will promote adoption of this technology. Atomic layer deposition (ALD) is a possible method for producing catalysts at a large scale when employed in a fluidized bed. ALD relies on sequential dosing of gas-phase precursors to grow a material layer by layer. We have synthesized platinum nanoparticles on a carbon particle support (Pt/C) by ALD for use in proton exchange membrane fuel cells (PEMFCs) and electrochemical hydrogen pumps. Platinum nanoparticles with different characteristics were deposited by changing two chemistries: the carbon substrate through functionalization; and the deposition process by use of either oxygen or hydrogen as ligand removing reactants. The metal depositing reactant was trimethyl(methylcyclopentadienyl)platinum(IV). Functionalizing the carbon substrate increased nucleation during deposition resulting in smaller and more dispersed nanoparticles. Use of hydrogen produced smaller nanoparticles than oxygen, due to a gentler hydrogenation reaction compared to using oxygen's destructive combustion reaction. Synthesized Pt/C materials were used as catalysts in an electrochemical hydrogen pump, a device used to separate hydrogen fuel from contaminants. Catalysts deposited by ALD on functionalized carbon using a hydrogen chemistry were the most successful hydrogen pumping catalysts, comparable to a commercial Pt/C catalyst. Synthesized Pt/C materials were also used as PEMFC catalysts. We found the ALD catalysts with lower platinum loading to be competitive with a commercial fuel cell catalyst, especially when exhibiting similar platinum particle characteristics. The functionalized carbon helped produce smaller and more dispersed platinum particles; however, it encouraged carbon corrosion within an electrode, severing electrical connections and lowering energy production. The most suitable chemistry for competitive Pt/C catalysts was produced by platinum ALD on unmodified carbon using hydrogen as a reactant. ALD is a promising method for fabricating electrocatalysts, which could help fuel cells become an economically viable alternative to fossil fuels.

Synthesis of seaweed based carbon acid catalyst by thermal decomposition of ammonium sulfate for biodiesel production

NASA Astrophysics Data System (ADS)

Ee, Tang Zo; Lim, Steven; Ling, Pang Yean; Huei, Wong Kam; Chyuan, Ong Hwai

2017-04-01

Experiment was carried out to study the feasibility of biomass derived solid acid catalyst for the production of biodiesel using Palm Fatty Acid Distillate (PFAD). Malaysia indigenous seaweed was selected as the biomass to be carbonized as the catalyst support. Sulfonation of seaweed based carbon material was carried out by thermal decomposition of ammonium sulfate, (NH4)2SO4. The effects of carbonization temperature at 200 to 600°C on the catalyst physical and chemical properties were studied. The effect of reaction parameters on the fatty acid methyl ester (FAME) yield was studied by varying the concentration of ammonium sulfate (5.0 to 40.0 w/v%) and thermal decomposition time (15 to 90 min). Characterizations of catalyst were carried out to study the catalyst surface morphology with Scanning Electron Microscope (SEM), acid density with back titration and functional group attached with FT-IR. Results showed that when the catalyst sulfonated with 10.0 w/v% ammonium sulfate solution and heated to 235°C for 30 min, the highest FAME yield achieved was 23.7% at the reaction condition of 5.0 wt.% catalyst loading, esterification time of 4 h, methanol to PFAD molar ratio of 20:1 at 100°C reaction temperature.

Researching the Possibility of Creating Highly Effective Catalysts for the Thermochemical Heat Regeneration and Hydrocarbon Reforming

DTIC Science & Technology

2006-11-01

PHYSICAL PROPERTIES OF THE PLASMA SPRAYING PROCESS The sprayed -on material is formed by gradual deposition of separate discretely solidifying with great... deposition processes and their ecological purity. Essentially, the method of ion-plasma spraying is evaporation of a metal (or alloy ) atoms from the...29 5.1 PHYSICAL PROPERTIES OF THE PLASMA SPRAYING PROCESS ...................34 6. CATALYST SUPPORTERS FOR THE 1ST STAGE OF

Microchemical Systems and Their Applications Workshop Held on 16-18 June 1999 in Reston, Virginia

DTIC Science & Technology

2000-03-29

USABLE BY- PRODUCT HYDROGEN, BUT COST OF THE PT COATED CERAMIC TUBES IS HIGH, HEAT TRANSFER EFFICIENCY IS LIMITED, AND THE RISK ASSOCIATED WITH...Monolith reactor Monolith Catalyst A Gas mixture i quartz tube T 1 Radiation Shields GC / analysis 3M Monolith Catalysts *-v.V...polyamide. MicroChannel patterned laminates are fabricated from polyamide while microfin -patterned laminates are fabricated from copper. In addition to

Electrical enhancement of direct methanol fuel cells by metal-plasma ion implantation Pt-Ru/C multilayer catalysts.

PubMed

Weng, Ko-Wei; Chen, Yung-Lin; Chen, Ya-Chi; Lin, Tai-Nan

2009-02-01

Direct methanol fuel cells (DMFC) have been widely studied owing to their simple cell configuration, high volume energy density, short start-up time, high operational reliability and other favorable characteristics. However, major limitations include high production cost, poisoning of the catalyst and methanol crossover. This study adopts a simple technique for preparing Pt-Ru/C multilayer catalysts, including magnetron sputtering (MS) and metal-plasma ion implantation (MPII). The Pt catalysts were sputtered onto the gas diffusion layer (GDL), followed by the implantation of Ru catalysts using MPII (at an accelerating voltage of 20 kV and an implantation dose of 1 x 10(16) ions/cm2). Pt-Ru is repeatedly processed to prepare Pt-Ru/C multilayer catalysts. The catalyst film structure and microstructure were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM), respectively. The cell performance was tested using a potential stat/galvano-stat. The results reveal that the membrane electrode assembly (MEA) of four multilayer structures enhances the cell performance of DMFC. The measured power density is 2.2 mW/cm2 at a methanol concentration of 2 M, with an OCV of 0.493 V.

Attrition resistant catalysts for slurry-phase Fischer-Tropsch process

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

K. Jothimurugesan

1999-11-01

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. Iron-based (Fe) catalysts are preferred catalysts for F-T because they are relatively inexpensive and possess reasonable activity for F-T synthesis (FTS). Their most advantages trait is their high water-gas shift (WGS) activity compared to their competitor, namely cobalt. This enables Fe F-T catalysts to process lowmore » H{sub 2}/CO ratio synthesis gas without an external shift reaction step. However, a serious problem with the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, make the separation of catalyst from the oil/wax product very difficult if not impossible, an d result in a steady loss of catalyst from the reactor. The objectives of this research were to develop a better understanding of the parameters affecting attrition of Fe F-T catalysts suitable for use in SBCRs and to incorporate this understanding into the design of novel Fe catalysts having superior attrition resistance.« less

Novel carbon nanostructures as catalyst support for polymer electrolyte membrane fuel cells

NASA Astrophysics Data System (ADS)

Natarajan, Sadesh Kumar

Polymer electrolyte membrane fuel cell (PEMFC) technology has advanced rapidly in recent years, with one of active area focused on improving the long-term performance of carbon supported catalysts, which has been recognized as one of the most important issues to be addressed for the commercialization of PEMFCs. The central part of a PEMFC is the membrane electrode assembly (MEA) which consists of two electrodes (anode and cathode) and a cation exchange membrane. These electrodes are commonly made of carbon black (most often, Vulcan XC-72) supported on carbon paper or carbon cloth backings. It is the primary objective of this thesis to prepare and investigate carbon nanostructures (CNS, licensed to Hydrogen Research Institute -- IRH, Quebec, Canada), the carbon material with more graphite component like carbon nanotubes (CNTs) for use as catalyst support in PEMFCs. High energy ball-milling of activated carbon along with transition metal catalysts under hydrogen atmosphere, followed by heat-treatment leads to nanocrystalline structures of carbon called CNS. However, CNS formed in the quartz tube after heat-treatment is inevitably accompanied by many impurities such as metal particles, amorphous carbon and other carbon nanoparticules. Such impurities are a serious impediment to detailed characterization of the properties of nanostructures. In addition, since the surface of CNS is itself rather inert, it is difficult to control the homogeneity and size distribution of Pt nanoparticules. In this thesis work, we demonstrated a novel mean to purify and functionalize CNS via acid-oxidation under reflux conditions. To investigate and quantify these nanostructures X-ray diffraction, electrical conductivity measurements, specific surface area measurements, thermogravimetric analysis, X-ray photoelectron spectroscopy and transmission electron microscopy studies were used. Cyclic voltammetry studies were performed on different samples to derive estimates for the relationship between the composition of the acid mixture and their influence in producing high density of surface functional groups. Such surface functionalization on CNS enhances the reactivity, improves the specificity and provides an avenue for Pt deposition. It was also shown that a 1:1 mixture of 7.5 M sulphuric acid and 15 M nitric acid have generated higher composition of non-acidic functional groups over other acid compositions discussed in this thesis. In this thesis, we also demonstrated a novel method to deposit and disperse platinum clusters on carbon nanotubes via a chemically specific nucleation mechanism. To investigate and quantify these platinized CNS X-ray diffraction, thermogravimetric analysis, atomic adsorption spectroscopy and high resolution transmission electron microscopy were used. An average Pt cluster size of 4 nm was dispersed homogeneously on CNS that was functionalized with the method described above. The corrosive nature of carbon support material is a crucial issue for the commercialization of PEMFC systems. Therefore, electrochemical oxidations of Pt/CNS compared with Pt/C were studied in this thesis with the aim to understand their durability as catalyst support in PEMFCs. The surface oxidation of the catalyst materials has been compared following potentiostatic treatments up to 200 h under condition simulating the PEMFC cathode environment (80°C, nitrogen purged 0.5 M sulphuric acid, and a constant potential of 1.2 V). The degradation of Pt catalysts and the carbon support was also evaluated by measuring the cell voltage at constant load after different oxidation intervals at 1.2 V. The agglomeration of Pt catalyst particles and the changes in surface functional groups of the carbon material at different intervals of electrochemical oxidation was evaluated using X-ray diffraction and thermogravimetric studies. The subsequent electrochemical characterization at different treatment time intervals by both the above methods suggests that CNS is electrochemically more stable than Vulcan XC-72 with less surface oxide formation and Pt surface area loss without sacrificing catalytic activity. (Abstract shortened by UMI.)

CO Sensing Performance of a Micro Thermoelectric Gas Sensor with AuPtPd/SnO₂ Catalyst and Effects of a Double Catalyst Structure with Pt/α-Al₂O₃.

PubMed

Goto, Tomoyo; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

2015-12-15

The CO sensing properties of a micro thermoelectric gas sensor (micro-TGS) with a double AuPtPd/SnO₂ and Pt/α-Al₂O₃ catalyst were investigated. While several nanometer sized Pt and Pd particles were uniformly dispersed on SnO₂, the Au particles were aggregated as particles measuring >10 nm in diameter. In situ diffuse reflectance Fourier transform Infrared spectroscopy (DRIFT) analysis of the catalyst showed a CO adsorption peak on Pt and Pd, but no clear peak corresponding to the interaction between CO and Au was detected. Up to 200 °C, CO combustion was more temperature dependent than that of H₂, while H₂ combustion was activated by repeated exposure to H₂ gas during the periodic gas test. Selective CO sensing of the micro-TGS against H₂ was attempted using a double catalyst structure with 0.3-30 wt% Pt/α-Al₂O₃ as a counterpart combustion catalyst. The sensor output of the micro-TGS decreased with increasing Pt content in the Pt/α-Al₂O₃ catalyst, by cancelling out the combustion heat from the AuPtPd/SnO₂ catalyst. In addition, the AuPtPd/SnO₂ and 0.3 wt% Pt/α-Al₂O₃ double catalyst sensor showed good and selective CO detection. We therefore demonstrated that our micro-TGS with double catalyst structure is useful for controlling the gas selectivity of CO against H₂.

The synergistic effect of phase heterojunction and surface heterojunction to improve photocatalytic activity of VO •-TiO2: the co-catalytic effect of H3PW12O40

NASA Astrophysics Data System (ADS)

Li, Haiyan; Cai, Shengnan; Yang, Pengfei; Bai, Yan; Dang, Dongbin

2018-06-01

With nanotube titanic acid (abbreviated as NTA) and the 12-tungstophosphoric acid (H3PW12O40• xH2O, denoted as HPW) as start materials, respectively, according to a simple hydrothermal process in acid medium, we successfully prepared HPW modified VO •-TiO2 composite photocatalysts. During heat treatment companied by the transformation of NTA to TiO2, a kind of single-electron-trapped oxygen vacancy (VO •) could be formed contributing to the visible light absorption of catalysts. The morphology, phase and chemical structure, optical and electronic properties, and so on of the produced catalysts with various HPW loadings are characterized. The size range of synthesized photocatalyst nanoparticles are about 10 50 nm. Taking aqueous rhodamine B (RhB) dye as model pollutant, we carried out photocatalytic activity test of the achieved catalysts, revealing that the hybrid photocatalysts display significantly enhanced visible light-driven ( λ ≥ 420 nm) photocatalytic activity for degradation of RhB. Among various catalysts, HPWN-0.1-120 composite with nominal loading of 0.1 g HPW and heat treatment temperature of 120 °C possesses the highest photocatalytic performance in visible light, which is closely related to the co-effect of phase heterojunction of rutile/anatase, surface heterojunction of anatase/HPW, and oxygen vacancy (VO •). The two types of heterojunction promote greatly the separation efficiency of photoelectrons and photoholes and oxygen vacancy lures response of catalysts to visible light.

Thermal Stability of Aqueous Polyurethanes Depending on the Applied Catalysts

PubMed Central

Cakic, Suzana; Nikolic, Goran; Lacnjevac, Caslav; Gligoric, Miladin; Stamenkovic, Jakov; Rajkovic, Milos B.; Barac, Miroljub

2006-01-01

The thermal stability of aqueous polyurethanes has been measured applying the thermogravimetric analysis. The aqueous polyurethanes (aqPUR) with catalysts of different selectivity have been studied by use of the dynamic method. To obtain degradations of 0.025, 0.05, and 0.10, employing the dynamic method, the heating rates of 0.5, 1, 2, 5, and 10 °C min-1 have been used in the range of 30-500 °C. Using the more selective catalysts in the aqueous polyurethanes, the total resulting time of the decompositon has been on the increase at all degrees of the degradation and at the particular starting temperature. This paper shows that the dynamic method based on the thermogravimetric analysis can be used to assess the thermal stability of the aqueous polyurethanes using the catalysts of different selectivity.

Facile solid-state synthesis of highly dispersed Cu nanospheres anchored on coal-based activated carbons as an efficient heterogeneous catalyst for the reduction of 4-nitrophenol

NASA Astrophysics Data System (ADS)

Wang, Shan; Gao, Shasha; Tang, Yakun; Wang, Lei; Jia, Dianzeng; Liu, Lang

2018-04-01

Coal-based activated carbons (AC) were acted as the support, Cu/AC catalysts were synthesized by a facile solid-state reaction combined with subsequent heat treatment. In Cu/AC composites, highly dispersed Cu nanospheres were anchored on AC. The catalytic activity for 4-nitrophenol (4-NP) was investigated, the effects of activation temperature and copper loading on the catalytic performance were studied. The catalysts exhibited very high catalytic activity and moderate chemical stability due to the unique characteristics of the particle-assembled nanostructures, the high surface area and the porous structure of coal-based AC and the good dispersion of metal particles. Design and preparation of non-noble metal composite catalysts provide a new direction for improving the added value of coal.

Thermal reactor for afterburning automotive internal combustion engine exhaust gases

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

Masaki, K.; Nagaishi, H.

1974-08-08

A thermal reactor for burning unburned components in exhaust gases of an internal combustion engine before emission to the atmosphere is described. An outer casing has an exhaust gas inlet connected to the exhaust ports, and an inner casing divides the reactor into an outer chamber and an inner chamber. The inner casing has an inlet from the outer chamber, an outlet to the atmosphere, and perforations opening to the outer chamber. An oxidation catalyst in the inner chamber promotes oxidation of the unburned components in the exhaust gases to generate oxidation reaction heat. A first secondary air injection nozzlemore » in the inner chamber between the oxidation catalyst and the outlet and a second secondary air injection nozzle in a portion upstream of the oxidation catalyst inject secondary air into oxidation catalyst.« less

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

Role of structural H 2O in TiO 2 nanotubes in enhancing Pt/C direct ethanol fuel cell anode electro-catalysts

NASA Astrophysics Data System (ADS)

Song, Huanqiao; Qiu, Xinping; Guo, Daojun; Li, Fushen

TiO 2 nanotubes (TNTs) with different structural water were obtained by heat treatment under different temperatures. The role of the structural water in TNTs co-catalyzing ethanol oxidation with Pt/C catalyst was studied systematically. Electrochemical studies using cyclic voltammetry and CO stripping voltammetry indicated that more structural water in TNTs was favorable for improving the tolerance of Pt/C to poisoning species; while chronoamperometry curves and repeated cyclic voltammograms showed that slightly less structural water in TNTs actually led to higher catalytic activity and better stability of Pt/C catalysts for ethanol oxidation. This strange result has been analyzed and was ascribed to the appropriate balance of bi-functional mechanism and ethanol transfer in the catalyst layer with less structural water.

Catalyst for Carbon Monoxide Oxidation

NASA Technical Reports Server (NTRS)

Davis, Patricia; Brown, Kenneth; VanNorman, John; Brown, David; Upchurch, Billy; Schryer, David; Miller, Irvin

2010-01-01

In many applications, it is highly desirable to operate a CO2 laser in a sealed condition, for in an open system the laser requires a continuous flow of laser gas to remove the dissociation products that occur in the discharge zone of the laser, in order to maintain a stable power output. This adds to the operating cost of the laser, and in airborne or space applications, it also adds to the weight penalty of the laser. In a sealed CO2 laser, a small amount of CO2 gas is decomposed in the electrical discharge zone into corresponding quantities of CO and O2. As the laser continues to operate, the concentration of CO2 decreases, while the concentrations of CO and O2 correspondingly increase. The increasing concentration of O2 reduces laser power, because O2 scavenges electrons in the electrical discharge, thereby causing arcing in the electric discharge and a loss of the energetic electrons required to boost CO2 molecules to lasing energy levels. As a result, laser power decreases rapidly. The primary object of this invention is to provide a catalyst that, by composition of matter alone, contains chemisorbed water within and upon its structure. Such bound moisture renders the catalyst highly active and very long-lived, such that only a small quantity of it needs to be used with a CO2 laser under ambient operating conditions. This object is achieved by a catalyst that consists essentially of about 1 to 40 percent by weight of one or more platinum group metals (Pt, Pd, Rh, Ir, Ru, Os, Pt being preferred); about 1 to 90 percent by weight of one or more oxides of reducible metals having multiple valence states (such as Sn, Ti, Mn, Cu, and Ce, with SnO2 being preferred); and about 1 to 90 percent by weight of a compound that can bind water to its structure (such as silica gel, calcium chloride, magnesium sulfate, hydrated alumina, and magnesium perchlorate, with silica gel being preferred). Especially beneficial results are obtained when platinum is present in the catalyst composition in an amount of about 5 to 25 (especially 7) percent by weight, SnO2 is present in an amount of about 30 to 40 (especially 40) percent by weight, and silica gel is present in an amount of 45 to 55 (especially 50) percent by weight. The composition of this catalyst was suggested by preliminary experiments in which a Pt/SnO2 catalyst was needed for bound water to enhance its activity. These experimental results suggested that if the water were bound to the surface, this water would enhance and prolong catalyst activity for long time periods. Because the catalyst is to be exposed to a laser gas mixture, and because a CO2 laser can tolerate only a very small amount of moisture, a hygroscopic support for the catalyst would provide the needed H2O into the gas. Silica gel is considered to be superior because of its property to chemisorb water on its surface over a wide range of moisture content.

Combustion characteristics of crude jatropha oil droplets using rhodium liquid as a homogeneous combustion catalyst

NASA Astrophysics Data System (ADS)

Nanlohy, Hendry Y.; Wardana, I. N. G.; Hamidi, N.; Yuliati, L.

2018-01-01

Combustion characteristics of crude jatropha oil droplet at room temperature with and without catalyst have been studied experimentally. Its combustion characteristics have been observed by igniting the oil droplet on a junction of a thermocouple, and the combustion characteristics of oil droplets are observed using a high-speed camera. The results show that the uniqueness of crude jatropha oil as alternative fuel is evidenced by the different stages of combustion caused by thermal cracking in burning droplets. The results also show that the role of the catalyst is not only an accelerator agent, but there are other unique functions and roles as a stabilizer. Moreover, the results also found that the catalyst was able to shorten the ignition timing and burnout time. This phenomenon proves that the presence of catalysts alters and weakens the structure of the triglyceride geometry so that the viscosity and flash point is reduced, the fuel absorbs heat well and flammable.

Thermal and catalytic slow pyrolysis of Calophyllum inophyllum fruit shell.

PubMed

Alagu, R M; Sundaram, E Ganapathy; Natarajan, E

2015-10-01

Pyrolysis of Calophyllum inophyllum shell was performed in a fixed bed pyrolyser to produce pyrolytic oil. Both thermal (without catalysts) and catalytic pyrolysis process were conducted to investigate the effect of catalysts on pyrolysis yield and pyrolysis oil characteristics. The yield of pyrolytic oil through thermal pyrolysis was maximum (41% wt) at 425 °C for particle size of 1.18 mm and heating rate of 40 °C/min. In catalytic pyrolysis the pyrolytic oil yield was maximum (45% wt) with both zeolite and kaolin catalysts followed by Al2O3 catalyst (44% wt). The functional groups and chemical components present in the pyrolytic oil are identified by Fourier Transform Infrared Spectroscopy (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS) techniques. This study found that C. inophyllum shell is a potential new green energy source and that the catalytic pyrolysis process using zeolite catalyst improves the calorific value and acidity of the pyrolytic oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Indirect Liquefaction of Coal-Biomass Mixture for Production of Jet Fuel with High Productivity and Selectivity

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

Gangwal, Santosh K; McCabe, Kevin

Coal to liquids (CTL) and coal-biomass to liquids (CBTL) processes were advanced by testing and demonstrating Southern Research’s sulfur tolerant nickel-based reforming catalyst and Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to clean, upgrade and convert syngas predominantly to jet fuel range hydrocarbon liquids, thereby minimizing expensive cleanup and wax upgrading operations. The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream and simulated syngas testing/demonstration. Reformer testing was performed to (1) reform tar and light hydrocarbons, (2) decompose ammonia in the presence H2S,more » and (3) deliver the required H2 to CO ratio for FT synthesis. FT Testing was performed to produce a product primarily containing C5-C20 liquid hydrocarbons and no C21+ waxy hydrocarbons with productivity greater than 0.7 gC5+/g catalyst/h, and at least 70% diesel and jet fuel range (C8-C20) hydrocarbon selectivity in the liquid product. A novel heat-exchange reactor system was employed to enable the use of the highly active FT catalyst and larger diameter reactors that results in cost reduction for commercial systems. Following laboratory development and testing, SR’s laboratory reformer was modified to operate in a Class 1 Div. 2 environment, installed at NCCC, and successfully tested for 125 hours using raw syngas. The catalyst demonstrated near equilibrium reforming (~90%) of methane and complete reforming/decomposition of tar and ammonia in the presence of up to 380 ppm H2S. For FT synthesis, SR modified and utilized a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport gasifier (TRIG). The test-rig developed in a previous project (DE-FE0010231) was modified to receive up to 7.5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of up to 6 L/day. Promising Chevron catalyst candidates in the size range from 70-200 μm were loaded onto SR’s 2-inch ID and 4-inch ID bench-scale reactors utilizing IntraMicron’s micro-fiber entrapped catalyst (MFEC) heat exchange reactor technology. During 2 test campaigns, the FT reactors were successfully demonstrated at NCCC using syngas for ~420 hours. The catalyst did not experience deactivation during the tests. SR’s thermo-syphon heat removal system maintained reactor operating temperature along the axis to within ±4 °C. The experiments gave a steady catalyst productivity of 0.7-0.8 g/g catalyst/h, liquid hydrocarbon selectivity of ~75%, and diesel and jet fuel range hydrocarbon selectivity in the liquid product as high as 85% depending on process conditions. A preliminary techno-economic evaluation showed that the SR technology-based 50,000 bpd plant had a 10 % lower total plant cost compared to a conventional slurry reactor based plant. Furthermore, because of the modular nature of the SR technology, it was shown that the total plant cost advantage increases to >35 % as the plant is scaled down to 1000 bpd.« less

Catalyst containing oxygen transport membrane

DOEpatents

Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

2012-12-04

A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

The Concept about the Regeneration of Spent Borohydrides and Used Catalysts from Green Electricity

PubMed Central

Liu, Cheng-Hong; Chen, Bing-Hung

2015-01-01

Currently, the Brown-Schlesinger process is still regarded as the most common and mature method for the commercial production of sodium borohydride (NaBH4). However, the metallic sodium, currently produced from the electrolysis of molten NaCl that is mass-produced by evaporation of seawater or brine, is probably the most costly raw material. Recently, several reports have demonstrated the feasibility of utilizing green electricity such as offshore wind power to produce metallic sodium through electrolysis of seawater. Based on this concept, we have made improvements and modified our previously proposed life cycle of sodium borohydride (NaBH4) and ammonia borane (NH3BH3), in order to further reduce costs in the conventional Brown-Schlesinger process. In summary, the revision in the concept combining the regeneration of the spent borohydrides and the used catalysts with the green electricity is reflected in (1) that metallic sodium could be produced from NaCl of high purity obtained from the conversion of the byproduct in the synthesis of NH3BH3 to devoid the complicated purification procedures if produced from seawater; and (2) that the recycling and the regeneration processes of the spent NaBH4 and NH3BH3 as well as the used catalysts could be simultaneously carried out and combined with the proposed life cycle of borohydrides.

Discovery of true electrochemical reactions for ultrahigh catalyst mass activity in water splitting

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

Mo, Jingke; Kang, Zhenye; Retterer, Scott T.

Better understanding of true electrochemical reaction behaviors in electrochemical energy devices has long been desired. It has been assumed so far that the reactions occur across the entire catalyst layer (CL), which is designed and fabricated uniformly with catalysts, conductors of protons and electrons, and pathways for reactants and products. By introducing a state-of-the-art characterization system, a thin, highly tunable liquid/gas diffusion layer (LGDL), and an innovative design of electrochemical proton exchange membrane electrolyzer cells (PEMECs), the electrochemical reactions on both microspatial and microtemporal scales are revealed for the first time. Surprisingly, reactions occur only on the CL adjacent tomore » good electrical conductors. On the basis of these findings, new CL fabrications on the novel LGDLs exhibit more than 50 times higher mass activity than conventional catalyst-coated membranes in PEMECs. In conclusion, this discovery presents an opportunity to enhance the multiphase interfacial effects, maximizing the use of the catalysts and significantly reducing the cost of these devices.« less

Discovery of true electrochemical reactions for ultrahigh catalyst mass activity in water splitting

PubMed Central

Mo, Jingke; Kang, Zhenye; Retterer, Scott T.; Cullen, David A.; Toops, Todd J.; Green, Johney B.; Mench, Matthew M.; Zhang, Feng-Yuan

2016-01-01

Better understanding of true electrochemical reaction behaviors in electrochemical energy devices has long been desired. It has been assumed so far that the reactions occur across the entire catalyst layer (CL), which is designed and fabricated uniformly with catalysts, conductors of protons and electrons, and pathways for reactants and products. By introducing a state-of-the-art characterization system, a thin, highly tunable liquid/gas diffusion layer (LGDL), and an innovative design of electrochemical proton exchange membrane electrolyzer cells (PEMECs), the electrochemical reactions on both microspatial and microtemporal scales are revealed for the first time. Surprisingly, reactions occur only on the CL adjacent to good electrical conductors. On the basis of these findings, new CL fabrications on the novel LGDLs exhibit more than 50 times higher mass activity than conventional catalyst-coated membranes in PEMECs. This discovery presents an opportunity to enhance the multiphase interfacial effects, maximizing the use of the catalysts and significantly reducing the cost of these devices. PMID:28138516

Assessment of the Pozzolanic Activity of a Spent Catalyst by Conductivity Measurement of Aqueous Suspensions with Calcium Hydroxide

PubMed Central

Velázquez, Sergio; Monzó, José M.; Borrachero, María V.; Payá, Jordi

2014-01-01

The pozzolanic activity of the spent catalyst produced by fluid catalytic cracking (FCC) has been studied by various methods in recent years. However, no quick and easy method has been reported for this activity based on the associated studies. In this work, the pozzolanic activity of a spent catalyst was investigated by measuring its electrical conductivity in aqueous suspensions of pozzolan/calcium hydroxide. The behavior of the FCC catalyst residue was compared to that of reactive and inert materials of similar chemical compositions. Further, the influence of temperature on the suspension was studied, and also, a new method was proposed in which the pozzolan/calcium hydroxide ratio was varied (with the initial presence of solid Ca(OH)2 in the system). It was concluded that the method is effective, fast and simple for evaluating the high reactivity of the catalyst. Therefore, this method is an alternative for the evaluation of the reactivity of pozzolanic materials. PMID:28788583

Discovery of true electrochemical reactions for ultrahigh catalyst mass activity in water splitting

DOE PAGES

Mo, Jingke; Kang, Zhenye; Retterer, Scott T.; ...

2016-11-18

Better understanding of true electrochemical reaction behaviors in electrochemical energy devices has long been desired. It has been assumed so far that the reactions occur across the entire catalyst layer (CL), which is designed and fabricated uniformly with catalysts, conductors of protons and electrons, and pathways for reactants and products. By introducing a state-of-the-art characterization system, a thin, highly tunable liquid/gas diffusion layer (LGDL), and an innovative design of electrochemical proton exchange membrane electrolyzer cells (PEMECs), the electrochemical reactions on both microspatial and microtemporal scales are revealed for the first time. Surprisingly, reactions occur only on the CL adjacent tomore » good electrical conductors. On the basis of these findings, new CL fabrications on the novel LGDLs exhibit more than 50 times higher mass activity than conventional catalyst-coated membranes in PEMECs. In conclusion, this discovery presents an opportunity to enhance the multiphase interfacial effects, maximizing the use of the catalysts and significantly reducing the cost of these devices.« less

Mounting improves heat-sink contact with beryllia washer

NASA Technical Reports Server (NTRS)

1966-01-01

To conduct heat away from electrical components that must be electrically insulated from a metal heat sink, a metal washer and a coil spring are placed between one end of the electrical component and the beryllia washer mounted on the heat sink. The thermal paths are formed by the component lead and base, the metal and beryllia washers, and the compressed spring.

Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

NASA Astrophysics Data System (ADS)

Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

2017-04-01

In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

Hydrogen sulfide-powered solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Liu, Man

2004-12-01

The potential utilization of hydrogen sulfide as fuel in solid oxide fuel cells has been investigated using an oxide-ion conducting YSZ electrolyte and different kinds of anode catalysts at operating temperatures in the range of 700--900°C and at atmospheric pressure. This technology offers an economically attractive alternative to present methods for removing toxic and corrosive H2S gas from sour gas streams and a promising approach for cogenerating electrical energy and useful chemicals. The primary objective of the present research was to find active and stable anode materials. Fuel cell experimental results showed that platinum was a good electrocatalyst for the conversion of H2S, but the Pt/YSZ interface was physically unstable due to the reversible formation and decomposition of PtS in H 2S streams at elevated temperatures. Moreover, instability of the Pt/YSZ interface was accelerated significantly by electrochemical reactions, and ultimately led to the detachment of the Pt anode from the electrolyte. It has been shown that an interlayer of TiO2 stabilized the Pt anode on YSZ electrolyte, thereby prolonging cell lifetime. However, the current output for a fuel cell using Pt/TiO2 as anode was not improved compared to using Pt alone. It was therefore necessary to investigate novel anode systems for H 2S-air SOFCs. New anode catalysts comprising composite metal sulfides were developed. These catalysts exhibited good electrical conductivity and better catalytic activity than Pt. In contrast to MoS2 alone, composite catalysts (M-Mo-S, M = Fe, Co, Ni) were not volatile and had superior stability. However, when used for extended periods of time, detachment of Pt current collecting film from anodes comprising metal sulfides alone resulted in a large increase in contact resistance and reduction in cell performance. Consequently, a systematic investigation was conducted to identify alternative electronic conductors for use with M-Mo-S catalysts. Anode catalysts comprising Co-Mo-S admixed with up to 10% Ag powder were found to have excellent performance and longevity, as well as improved electrical contact when compared with Pt/M-Mo-S anode systems. The highest current density of 450 mA/cm2 and power density of 115 mW/cm2 were achieved with an anode that consisted of 95% (Co-Mo-S) and 5% Ag.

Production of single-walled carbon nanotube grids

DOEpatents

Hauge, Robert H; Xu, Ya-Qiong; Pheasant, Sean

2013-12-03

A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

IR-doped ruthenium oxide catalyst for oxygen evolution

NASA Technical Reports Server (NTRS)

Valdez, Thomas I. (Inventor); Narayanan, Sekharipuram R. (Inventor)

2012-01-01

A method for preparing a metal-doped ruthenium oxide material by heating a mixture of a doping metal and a source of ruthenium under an inert atmosphere. In some embodiments, the doping metal is in the form of iridium black or lead powder, and the source of ruthenium is a powdered ruthenium oxide. An iridium-doped or lead-doped ruthenium oxide material can perform as an oxygen evolution catalyst and can be fabricated into electrodes for electrolysis cells.

Catalyst surfaces for the chromous/chromic redox couple

NASA Technical Reports Server (NTRS)

Giner, J. D.; Cahill, K. J. (Inventor)

1980-01-01

An electricity producing cell of the reduction-oxidation (REDOX) type is described. The cell is divided into two compartments by a membrane, each compartment containing a solid inert electrode. A ferrous/ferric couple in a chloride solution serves as a cathode fluid which is circulated through one of the compartments to produce a positive electric potential disposed therein. A chromic/chromous couple in a chloride solution serves as an anode fluid which is circulated through the second compartment to produce a negative potential on an electrode disposed therein. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which was added to the anode fluid. If the REDOX cell is then discharged, the current flows between the electrodes causing the lead to deplate from the negative electrode and the metal coating on the electrode will act as a catalyst to cause increased current density.

Characterization of electrical properties in axial Si-Ge nanowire heterojunctions using off-axis electron holography and atom-probe tomography

DOE PAGES

Gan, Zhaofeng; Perea, Daniel E.; Yoo, Jinkyoung; ...

2016-09-13

Doped Si-Ge nanowire (NW) heterojunctions were grown using the vapor-liquid-solid method with AuGa and Au catalyst particles. Transmission electron microscopy and off-axis electron holography (EH) were used to characterize the nanostructure and to measure the electrostatic potential profile across the junction resulting from electrically active dopants, while atom-probe tomography (APT) was used to determine the Si, Ge and total (active and inactive) dopant concentration profiles. A comparison of the measured potential profile with simulations indicated that Ga dopants unintentionally introduced during AuGa catalyst growth were electronically inactive despite APT results that showed considerable amounts of Ga in the Si region.more » 10% P in Ge and 100% B in Si were estimated to be activated, which was corroborated by in situ electron-holography biasing experiments. This combination of EH, APT, in situ biasing and simulations allows a better knowledge and understanding of the electrically active dopant distributions in NWs.« less

Apparatus and method for pyroelectric power conversion

DOEpatents

Olsen, Randall B.

1984-01-01

Apparatus and method for converting heat to electrical energy by the use of one or more capacitors having temperature dependent capacitance. The capacitor is cycled between relatively high and relatively low temperatures by successive thermal contact with relatively high and relatively low temperature portions of a heat transfer medium having a temperature gradient therein. Upon heating of the capacitor, the capacitance thereof is reduced, so that a charge therein is caused to expand into associated external circuitry in which it is available to do electrical work. The capacitor is then cooled and recharged and the cycle is repeated. The electrical output of the capacitor results from the regenerative delivery of heat to and removal of heat from the capacitor by the heat transfer medium, and efficient conversion of heat to electric energy is thereby effected.

Biodiesel production from waste frying oil using waste animal bone and solar heat.

PubMed

Corro, Grisel; Sánchez, Nallely; Pal, Umapada; Bañuelos, Fortino

2016-01-01

A two-step catalytic process for the production of biodiesel from waste frying oil (WFO) at low cost, utilizing waste animal-bone as catalyst and solar radiation as heat source is reported in this work. In the first step, the free fatty acids (FFA) in WFO were esterified with methanol by a catalytic process using calcined waste animal-bone as catalyst, which remains active even after 10 esterification runs. The trans-esterification step was catalyzed by NaOH through thermal activation process. Produced biodiesel fulfills all the international requirements for its utilization as a fuel. A probable reaction mechanism for the esterification process is proposed considering the presence of hydroxyapatite at the surface of calcined animal bones. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential pyrolysis of plastic to recover polystyrene HCL and terephthalic acid

DOEpatents

Evans, Robert J.; Chum, Helena L.

1995-01-01

A process of pyrolyzing plastic waste feed streams containing polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene to recover polystyrene HCl and terephthalic acid comprising: heating the plastic waste feed stream to a first temperature; adding an acid or base catalyst on an oxide or carbonate support; heating the plastic waste feed stream to pyrolyze polyethylene terephthalate and polyvinyl chloride; separating terephthalic acid or HCl; heating to a second temperature to pyrolyze polystyrene; separating styrene; heating the waste feed stream to a third temperature to pyrolyze polyethylene; and separating hydrocarbons.

Attrition Resistant Iron-Based Fischer-Tropsch Catalysts

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

Jothimurugesan, K.; Goodwin, J.G.; Spivey, J.J.

1997-03-26

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRS) can largely solve this problem. Iron-based (Fe) catalysts are preferred catalysts for F-T when using low CO/H{sub 2} ratio synthesis gases derived from modem coal gasifiers. This is because in addition to reasonable F-T activity, the FT catalysts also possess high water gas shift (WGS) activity. However, a serious problem withmore » the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, making the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance of Fe F-T catalysts suitable for use in SBCRs and to incorporate this understanding into the design of novel Fe catalysts having superior attrition resistance. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity.« less

Attrition Resistant Iron-Based Fischer-Tropsch Catalysts.

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

Jothimurugesan, K.; Goodwin, J.S.; Spivey, J.J.

1997-09-22

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO and H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. Iron-based (Fe) catalysts are preferred catalysts for F-T when using low CO/H{sub 2} ratio synthesis gases derived from modern coal gasifiers. This is because in addition to reasonable F-T activity, the F-T catalysts also possess high water gas shift (WGS) activity. However, a seriousmore » problem with the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, making the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance of Fe F-T catalysts suitable for use in SBCRs and to incorporate this understanding into the design of novel Fe catalysts having superior attrition resistance. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity.« less

GROUNDWATER AND SOIL REMEDIATION USING ELECTRICAL FIELD

EPA Science Inventory

Enhancements of contaminants removal and degradation in low permeability soils by electrical fields are achieved by the processes of electrical heating, electrokinetics, and electrochemical reactions. Electrical heating increases soil temperature resulting in the increase of cont...

Conversion of ammonia into hydrogen and nitrogen by reaction with a sulfided catalyst

DOEpatents

Matthews, Charles W.

1977-01-01

A method is provided for removing ammonia from the sour water stream of a coal gasification process. The basic steps comprise stripping the ammonia from the sour water; heating the stripped ammonia to a temperature from between 400.degree. to 1,000.degree. F; passing the gaseous ammonia through a reactor containing a sulfided catalyst to produce elemental hydrogen and nitrogen; and scrubbing the reaction product to obtain an ammonia-free gas. The residual equilibrium ammonia produced by the reactor is recycled into the stripper. The ammonia-free gas may be advantageously treated in a Claus process to recover elemental sulfur. Iron sulfide or cobalt molybdenum sulfide catalysts are used.

Industrial Catalysis: A Practical Guide

NASA Astrophysics Data System (ADS)

Farrauto, Robert J.

Every student of chemistry, material science, and chemical engineering should be schooled in catalysis and catalytic reactions. The reason is quite simple; most products produced in the chemical and petroleum industry utilize catalysts to enhance the rate of reaction and selectivity to desired products. Catalysts are also extensively used to minimize harmful byproduct pollutants in environmental applications. Enhanced reaction rates translate to higher production volumes at lower temperatures with smaller and less exotic materials of construction necessary. When a highly selective catalyst is used, large volumes of desired products are produced with virtually no undesirable byproducts. Gasoline, diesel, home heating oil, and aviation fuels owe their performance quality to catalytic processing used to upgrade crude oil.

Effect of various gases and chemical catalysts on phenol degradation pathways by pulsed electrical discharges.

PubMed

Shen, Yongjun; Lei, Lecheng; Zhang, Xingwang; Zhou, Minghua; Zhang, Yi

2008-02-11

The processes of phenol degradation by pulsed electrical discharges were investigated under several kinds of discharge atmospheres (oxygen, argon, nitrogen and ozone) and chemical catalysts (ferrous ion and hydrogen peroxide). The temporal variations of the concentrations of phenol and the intermediate products were monitored by HPLC and GC-MS, respectively. It has been found that the effect of various gases bubbling on phenol degradation rate ranked in the following order: oxygen-containing ozone>oxygen>argon>nitrogen. The high gas bubbling flow rate was beneficial to the removal of phenol. It was found that the degradation proceeded differently when in the presence and absence of catalysts. The phenol removal rate was increased when ferrous ion was added. This considerable enhancement may be due to the Fenton's reaction. What's more, putting the chemical additives hydrogen peroxide into the reactor led to a dramatic increase in phenol degradation rate. The mechanism was due to the direct or indirect photolysis and pyrolysis destruction in plasma channel. Furthermore, the intermediate products were monitored by GC-MS under three degradation conditions. More THBs were generated under degradation conditions without gases bubbling or adding any catalyst, and more DHBs under the condition of adding ferrous ion, and more carboxylic acids under the condition of oxygen-containing ozone gas bubbling. Consequently, three distinct degradation pathways based on different conditions were proposed.

Development of a continuous bioconversion system using a thermophilic whole-cell biocatalyst.

PubMed

Ninh, Pham Huynh; Honda, Kohsuke; Yokohigashi, Yukako; Okano, Kenji; Omasa, Takeshi; Ohtake, Hisao

2013-03-01

The heat treatment of recombinant mesophilic cells having heterologous thermophilic enzymes results in the denaturation of indigenous mesophilic enzymes and the elimination of undesired side reactions; therefore, highly selective whole-cell catalysts comparable to purified enzymes can be readily prepared. However, the thermolysis of host cells leads to the heat-induced leakage of thermophilic enzymes, which are produced as soluble proteins, limiting the exploitation of their excellent stability in repeated and continuous reactions. In this study, Escherichia coli cells having the thermophilic fumarase from Thermus thermophilus (TtFTA) were treated with glutaraldehyde to prevent the heat-induced leakage of the enzyme, and the resulting cells were used as a whole-cell catalyst in repeated and continuous reactions. Interestingly, although electron microscopic observations revealed that the cellular structure of glutaraldehyde-treated E. coli was not apparently changed by the heat treatment, the membrane permeability of the heated cells to relatively small molecules (up to at least 3 kDa) was significantly improved. By applying the glutaraldehyde-treated E. coli having TtFTA to a continuous reactor equipped with a cell-separation membrane filter, the enzymatic hydration of fumarate to malate could be operated for more than 600 min with a molar conversion yield of 60% or higher.

Development of a Continuous Bioconversion System Using a Thermophilic Whole-Cell Biocatalyst

PubMed Central

Ninh, Pham Huynh; Yokohigashi, Yukako; Okano, Kenji; Omasa, Takeshi; Ohtake, Hisao

2013-01-01

The heat treatment of recombinant mesophilic cells having heterologous thermophilic enzymes results in the denaturation of indigenous mesophilic enzymes and the elimination of undesired side reactions; therefore, highly selective whole-cell catalysts comparable to purified enzymes can be readily prepared. However, the thermolysis of host cells leads to the heat-induced leakage of thermophilic enzymes, which are produced as soluble proteins, limiting the exploitation of their excellent stability in repeated and continuous reactions. In this study, Escherichia coli cells having the thermophilic fumarase from Thermus thermophilus (TtFTA) were treated with glutaraldehyde to prevent the heat-induced leakage of the enzyme, and the resulting cells were used as a whole-cell catalyst in repeated and continuous reactions. Interestingly, although electron microscopic observations revealed that the cellular structure of glutaraldehyde-treated E. coli was not apparently changed by the heat treatment, the membrane permeability of the heated cells to relatively small molecules (up to at least 3 kDa) was significantly improved. By applying the glutaraldehyde-treated E. coli having TtFTA to a continuous reactor equipped with a cell-separation membrane filter, the enzymatic hydration of fumarate to malate could be operated for more than 600 min with a molar conversion yield of 60% or higher. PMID:23335777

Analysis of the energy efficiency of the implementation power electric generated modules in the CHS

NASA Astrophysics Data System (ADS)

Sukhikh, A. A.; Milyutin, V. A.; Lvova, A. M.

2017-11-01

Application on the Central heat source (CHS) local generation of electricity is primarily aimed at solving problems of own needs of electric energy that not only guarantees the independence of the work of the CHS from external electrical networks, but will prevent the stop of heat supply of consumers and defrosting heating networks in case of accidents in electrical networks caused by natural or anthropogenic factors. Open the prospects of electric power supply stand-alone objects, such commercial or industrial objects on the territory of a particular neighborhood.

Cermet anode with continuously dispersed alloy phase and process for making

DOEpatents

Marschman, Steven C.; Davis, Norman C.

1989-01-01

Cermet electrode compositions and methods for making are disclosed which comprise NiO--NiFe.sub.2 O.sub.4 --Cu--Ni. Addition of an effective amount of a metallic catalyst/reactant to a composition of a nickel/iron/oxide, NiO, copper, and nickel produces a stable electrode having significantly increased electrical conductivity. The metallic catalyst functions to disperse the copper and nickel as an alloy continuously throughout the oxide phase of the cermet to render the electrode compositon more highly electrically conductive than were the third metal not present in the base composition. The third metal is preferably added to the base composition as elemental metal and includes aluminum, magnesium, sodium and gallium. The elemental metal is converted to a metal oxide during the sintering process.

Space electric power design study. [laser energy conversion

NASA Technical Reports Server (NTRS)

Martini, W. R.

1976-01-01

The conversion of laser energy to electrical energy is discussed. Heat engines in which the laser heats the gas inside the engine through a window as well as heat engines in which the gas is heated by a thermal energy storage reservoir which has been heated by laser radiation are both evaluated, as well as the necessary energy storage, transmission and conversion components needed for a full system. Preliminary system concepts are presented and a recommended development program is outlined. It appears possible that a free displacer Stirling engine operating directly a linear electric generator can convert 65% of the incident laser energy into electricity.

Investigation of Ultrasonics as a tool for energy efficient recycling of Lactic acid from postconsumer PLA products

NASA Astrophysics Data System (ADS)

Srinivasan, Gowrishankar

The growing use of "ecofriendly," biodegradable polymers have created a need for a suitable recycling technique because, unlike petroleum derived plastics, their properties deteriorate during conventional recycling. These new techniques must be cost efficient and yield material properties same as virgin polymer. This research investigates the effectiveness of high-power ultrasonics as an efficient technique to recover lactic acid from postconsumer polylactic acid (PLA) products. Polylactic acid is a commercially available bioplastic derived from corn starch and/or sugar cane that is biorenewable and compostable (biodegradable). The various ongoing researches to recover lactic acid from PLA employ a common platform of high temperature, high pressure (HTHP) to effect polymer hydrolysis. The energy intensiveness of these HTHP processes prompted this work to investigate ultrasonics as an low energy alternative process to cause PLA depolymerization. The energy consumption and the time required for depolymerization were utilized as the metrics to quantify and compare depolymerization enhanced by ultrasonics with hot-bath technique. The coupled effect of catalysts concentration and different solvents, along with ultrasonic were studied based on preliminary trial results. In addition, the correlation between the rates of de-polymerization was analyzed for ultrasonic amplitude, treatment time, and catalyst concentration and types. The results indicate that depolymerization of PLA was largely effected by heating caused by ultrasonic-induced cavitations. Other effects of ultrasonics, namely cavitations and acoustic streaming, were shown to have minimal effects in enhancing depolymerization. In fact, thermal energy predominately affected the reaction kinetics; the heat introduced by conventional method (i.e., electrical heaters) was more efficient than ultrasonic heating in terms of energy (for depolymerization) per unit mass of PLA and depolymerizing time. The degree of crystallinity also was an important factor that affected the reaction kinetics of depolymerization. It was found that amorphous PLA de-polymerized faster compared to semi-crystalline PLA under the same conditions. While the depolymerization of PLA was anticipated to require 15 to 30 minutes, or extreme conditions [40], it was determined that with K2CO3 or NaOH catalysts and methanol media as the conditions, PLA could be fully de-polymerized within a few minutes. This information provided insight for effective pathways for the depolymerization of PLA, reducing the environmental impact of material use on the environment. The effects of the ultrasonics were modeled with finite element analysis based on fundamental concepts. The predictions from the modeling were confirmed by studying real-time streaming and fluid flow inside the treatment cell utilizing particle image Velocimetry (PIV). The FEA (finite element analysis) models of ultrasonic streaming were verified and were in reasonable agreement with the experimental values, validating simple assumptions for future researchers.

8. QUENCHING MECHANISM FOR THE CONTINUOUS ELECTRIC FURNACE HEAT TREATING ...

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

8. QUENCHING MECHANISM FOR THE CONTINUOUS ELECTRIC FURNACE HEAT TREATING LINE AT THE HEAT TREATMENT PLANT OF THE DUQUESNE WORKS. - U.S. Steel Duquesne Works, Heat Treatment Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Conversion efficiency of an energy harvester based on resonant tunneling through quantum dots with heat leakage.

PubMed

Kano, Shinya; Fujii, Minoru

2017-03-03

We study the conversion efficiency of an energy harvester based on resonant tunneling through quantum dots with heat leakage. Heat leakage current from a hot electrode to a cold electrode is taken into account in the analysis of the harvester operation. Modeling of electrical output indicates that a maximum heat leakage current is not negligible because it is larger than that of the heat current harvested into electrical power. A reduction of heat leakage is required in this energy harvester in order to obtain efficient heat-to-electrical conversion. Multiple energy levels of a quantum dot can increase the output power of the harvester. Heavily doped colloidal semiconductor quantum dots are a possible candidate for a quantum-dot monolayer in the energy harvester to reduce heat leakage, scaling down device size, and increasing electrical output via multiple discrete energy levels.

Nuclear qualified in-containment electrical connectors and method of connecting electrical conductors

DOEpatents

Powell, J. G.

1991-01-01

A nuclear qualified in-containment electrical connection comprises an insulated, sheathed instrument lead having electrical conductors extending from one end thereof to provide two exposed lead wires, a watertight cable having electrical conducting wires therein and extending from one end of the cable to provide two lead wires therefrom, two butt splice connectors each connecting the ends of respective ones of the lead wires from the instrument lead and cable, a length of heat shrinkable plastic tubing positioned over each butt splice connector and an adjacent portion of a respective lead wire from the cable and heat shrunk into position, a length of heat shrinkable plastic tubing on the end portion of the instrument lead adjacent the lead wires therefrom and heat shrunk thereon and a length of outer heat shrinkable plastic tubing extending over the end portion of the instrument lead and the heat shrinkable tubing thereon and over the butt splice connectors and a portion of the cable adjacent the cable lead lines, the outer heat shrinkable tubing being heat shrunk into sealing position on the instrument lead and cable.

Micro-Cogeneration Incl. The Conversion of Chemical Energy of Biomass to Electric Energy and the Low Potential Heat

NASA Astrophysics Data System (ADS)

Huzvar, Jozef; Kapjor, Andrej

2011-06-01

This article deals with combined production of heat and electricity for small premises, such as households, where energy consumption is around few kilowatts. This proposal of micro co-generation unit uses as a heat source an automatic burner for combustion of wood pellets. Construction of an equipment for the heat transport can be designed using different basic ways of heat transfer. Electricity is produced by the two-stroke steam engine and the generator.

Performance of Ni/dolomite pellet catalyst on gas distribution from cassava rhizome gasification with a modular fixed-bed gasifier.

PubMed

Sricharoenchaikul, V; Atong, D; Sornkade, P; Nisamaneenate, J

2017-05-01

Thermal conversion of cassava rhizome was performed using a modular downdraft gasifier with the addition of Ni-based catalysts as promising tar eliminating and produced gas upgrading techniques. The activities of a synthesized 5% Ni/dolomite pellet catalyst prepared by impregnation method were investigated in a secondary reactor downstream of the gasifier. High reforming activity of the Ni/dolomite pellet catalyst on tar reduction was achieved. The conversion to H 2 and CO was improved via steam reforming of methane and char reaction with CO 2 . Moreover, the formation of CH 4 and C x H y was diminished through the tar or condensable hydrocarbon reformed on the catalyst surface. The carbon and hydrogen conversions of cassava rhizome with prepared catalyst were 83.79% and 61.78%, respectively, at an air flow rate of 1.98 m 3 /hr. At this condition, tar formation was low, while the lower heating value was 4.39 MJ/m 3 and H 2 to CO molar ratio was 1.22. Generally, the addition of a catalyst not only enhanced gas production, but also reduced tar and particulate matter generation; thus, its implementation should help lessen the pollution control requirement and cost of operation, while allowing higher quality fuel gas production.

Apparatus and method for pyroelectric power conversion

DOEpatents

Olsen, R.B.

1984-01-10

Apparatus and method for converting heat to electrical energy by the use of one or more capacitors having temperature dependent capacitance are disclosed. The capacitor is cycled between relatively high and relatively low temperatures by successive thermal contact with relatively high and relatively low temperature portions of a heat transfer medium having a temperature gradient therein. Upon heating of the capacitor, the capacitance thereof is reduced, so that a charge therein is caused to expand into associated external circuitry in which it is available to do electrical work. The capacitor is then cooled and recharged and the cycle is repeated. The electrical output of the capacitor results from the regenerative delivery of heat to and removal of heat from the capacitor by the heat transfer medium, and efficient conversion of heat to electric energy is thereby effected. 12 figs.

Fuel Composition Analysis of Endothermically Heated JP-8 Fuel for Use in a Pulse Detonation Engine

DTIC Science & Technology

2008-06-01

detonation engine (PDE) was extracted via zeolite catalyst coated concentric tube-counter flow heat exchangers to produce supercritical pyrolytic conditions...gas chromatography flame ionization and thermal conductivity detectors ............................................. 68 Table B.1. Elemental bias... chromatography ...................... 98 Table D.1b. Products found in the liquid sample by gas chromatography (continued) ... 99 Table D.1c

PET-modified red mud as catalysts for oxidative desulfurization reactions.

PubMed

do Prado, Nayara T; Heitmann, Ana P; Mansur, Herman S; Mansur, Alexandra A; Oliveira, Luiz C A; de Castro, Cinthia S

2017-07-01

This work describes the synthesis of catalysts based on red mud/polyethylene terephthalate (PET) composites and their subsequent heat treatment under N 2 atmosphere. The materials were characterized by scanning electron microscopy (SEM), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG) analysis and N 2 adsorption/desorption. The catalysts were evaluated in the oxidative desulfurization reaction of dibenzothiophene (DBT) in a biphasic system. The results indicated that the PET impregnation on red mud increased the affinity of the catalyst with the nonpolar phase (fuel), in which the contaminant was dissolved, allowing a higher conversion (up to 80%) and selectivity to the corresponding dibenzothiophene sulfone. The sulfone compound is more polar than DBT and diffused into the polar solvent as indicated by the data obtained via gas chromatography-mass spectrometry (GC-MS). Copyright © 2017. Published by Elsevier B.V.

Palladium-tin catalysts for the direct synthesis of H 2O 2 with high selectivity

DOE PAGES

Freakley, Simon J.; He, Qian; Harrhy, Jonathan H.; ...

2016-02-25

The direct synthesis of hydrogen peroxide (H 2O 2 ) from H 2 and O 2 represents a potentially atom-efficient alternative to the current industrial indirect process. We show that the addition of tin to palladium catalysts coupled with an appropriate heat treatment cycle switches off the sequential hydrogenation and decomposition reactions, enabling selectivities of >95% toward H 2O 2 . This effect arises from a tin oxide surface layer that encapsulates small Pd-rich particles while leaving larger Pd-Sn alloy particles exposed. In conclusion, we show that this effect is a general feature for oxide-supported Pd catalysts containing an appropriatemore » second metal oxide component, and we set out the design principles for producing high-selectivity Pd-based catalysts for direct H 2O 2 production that do not contain gold.« less

Direct growth and patterning of multilayer graphene onto a targeted substrate without an external carbon source.

PubMed

Kang, Dongseok; Kim, Won-Jun; Lim, Jung Ah; Song, Yong-Won

2012-07-25

Using only a simple tube furnace, we demonstrate the synthesis of patterned graphene directly on a designed substrate without the need for an external carbon source. Carbon atoms are absorbed onto Ni evaporator sources as impurities, and incorporated into catalyst layers during the deposition. Heat treatment conditions were optimized so that the atoms diffused out along the grain boundaries to form nanocrystals at the catalyst-substrate interfaces. Graphene patterns were obtained under patterned catalysts, which restricted graphene formation to within patterned areas. The resultant multilayer graphene was characterized by Raman spectroscopy and transmission electron microscopy to verify the high crystallinity and two-dimensional nanomorphology. Finally, a metal-semiconductor diode with a catalyst-graphene contact structure were fabricated and characterized to assess the semiconducting properties of the graphene sheets with respect to the display of asymmetric current-voltage behavior.

Population and hierarchy of active species in gold iron oxide catalysts for carbon monoxide oxidation.

PubMed

He, Qian; Freakley, Simon J; Edwards, Jennifer K; Carley, Albert F; Borisevich, Albina Y; Mineo, Yuki; Haruta, Masatake; Hutchings, Graham J; Kiely, Christopher J

2016-09-27

The identity of active species in supported gold catalysts for low temperature carbon monoxide oxidation remains an unsettled debate. With large amounts of experimental evidence supporting theories of either gold nanoparticles or sub-nm gold species being active, it was recently proposed that a size-dependent activity hierarchy should exist. Here we study the diverging catalytic behaviours after heat treatment of Au/FeO x materials prepared via co-precipitation and deposition precipitation methods. After ruling out any support effects, the gold particle size distributions in different catalysts are quantitatively studied using aberration corrected scanning transmission electron microscopy (STEM). A counting protocol is developed to reveal the true particle size distribution from HAADF-STEM images, which reliably includes all the gold species present. Correlation of the populations of the various gold species present with catalysis results demonstrate that a size-dependent activity hierarchy must exist in the Au/FeO x catalyst.

Catalyst comprising Ir or Ir and Ru for hydrazine decomposition

NASA Technical Reports Server (NTRS)

Armstrong, Warren E. (Inventor); Voge, Hervey H. (Inventor); Ryland, Lloyd B. (Inventor)

1978-01-01

A catalyst for hydrazine decomposition consisting essentially of a carrier having a pore volume of at least 0.1 cubic centimeters per gram and a specific surface area, measured in square meters per gram, equal to 195 (C.sub.p + 0.013 + 0.736 V.sub.p) where C.sub.p is the specific heat capacity of the carrier at about 25.degree. C in calories per gram per degree and V.sub.p is the pore volume of the carrier in cubic centimeters per gram and metal of the group consisting of iridium, and mixtures consisting of iridium and ruthenium deposited on said carrier in an amount between 20% and about 40% by weight of the catalyst and distributed through the pores thereof in discrete particles sufficiently separated from each other so that they do not sinter or fuse together when the catalyst is at hydrazine decomposition temperature.

Corrosion-resistant catalyst supports for phosphoric acid fuel cells

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

Kosek, J.A.; Cropley, C.C.; LaConti, A.B.

High-surface-area carbon blacks such as Vulcan XC-72 (Cabot Corp.) and graphitized carbon blacks such as 2700{degree}C heat-treated Black Pearls 2000 (HTBP) (Cabot Corp.) have found widespread applications as catalyst supports in phosphoric acid fuel cells (PAFCs). However, due to the operating temperatures and pressures being utilized in PAFCs currently under development, the carbon-based cathode catalyst supports suffer from corrosion, which decreases the performance and life span of a PAFC stack. The feasibility of using alternative, low-cost, corrosion-resistant catalyst support (CRCS) materials as replacements for the cathode carbon support materials was investigated. The objectives of the program were to prepare high-surface-areamore » alternative supports and to evaluate the physical characteristics and the electrochemical stability of these materials. The O{sub 2} reduction activity of the platinized CRCS materials was also evaluated. 2 refs., 3 figs.« less

Investigating catalyst coated membrane equilibration time for polymer electrolyte membrane fuel cell manufacturing

NASA Astrophysics Data System (ADS)

Cote, Philippe

Mercedes-Benz Canada Inc., Fuel Cell Division, manufactures polymer electrolyte membrane fuel cell stacks for use in vehicles. The manufacturing line is being optimized for efficiency and quality control, in order to uphold the high standards of Mercedes-Benz Inc. vehicles. In an operating polymer electrolyte membrane fuel cell, the catalyst coated membrane facilitates the electrochemical reaction that generates electricity. This research examines the equilibration of catalyst coated membrane rolls to controlled temperature and humidity conditions, before they are used in the manufacturing of polymer electrolyte membrane fuel cells. Equilibration involves allowing the water content in the catalyst coated membrane to stabilize at the controlled conditions, in order to reduce mechanical stress in the material for better manufacturability. Initial equilibration measurements were conducted on discrete catalyst coated membrane samples using novel electronic conductivity measurements of the catalyst layer, and compared to ionic conductivity measurements of the membrane. Electronic conductivity measurements are easier to implement in the manufacturing environment than the more complex ionic conductivity measurements. When testing discrete catalyst coated membrane samples in an environmental chamber, the equilibration trends for the measured ionic and electronic conductivity signals were similar enough to permit us to adapt the electronic conductivity measurements for catalyst coated membrane in roll form. Equilibration measurements of catalyst coated membrane rolls were optimized to achieve a robust and repeatable procedure which could be used in the manufacturing environment at Mercedes-Benz Canada Inc., Fuel Cell Division.

Catalyst containing oxygen transport membrane

DOEpatents

Lane, Jonathan A.; Wilson, Jamie R.; Christie, Gervase Maxwell; Petigny, Nathalie; Sarantopoulos, Christos

2017-02-07

A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a microstructure exhibiting substantially uniform pore size distribution as a result of using PMMA pore forming materials or a bi-modal particle size distribution of the porous support layer materials. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

Determination of the NOx Loading of an Automotive Lean NOx Trap by Directly Monitoring the Electrical Properties of the Catalyst Material Itself

PubMed Central

Fremerey, Peter; Reiß, Sebastian; Geupel, Andrea; Fischerauer, Gerhard; Moos, Ralf

2011-01-01

Recently, it has been shown that the degree of loading of several types of automotive exhaust aftertreatment devices can be directly monitored in situ and in a contactless way by a microwave-based method. The goal of this study was to clarify whether this method can also be applied to NOx storage and reduction catalysts (lean NOx traps) in order to obtain further knowledge about the reactions occurring in the catalyst and to compare the results with those obtained by wirebound NOx loading sensors. It is shown that both methods are able to detect the different catalyst loading states. However, the sensitivity of the microwave-based method turned out to be small compared to that previously observed for other exhaust aftertreatment devices. This may limit the practical applicability of the microwave-based NOx loading detection in lean NOx traps. PMID:22164074

Surface Immobilization of Molecular Electrocatalysts for Energy Conversion

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

Bullock, R. Morris; Das, Atanu K.; Appel, Aaron M.

2017-03-22

Electrocatalysts are critically important for a secure energy future, as they facilitate the conversion between electrical energy and chemical energy. Molecular catalysts offer precise control of their structure, and the ability to modify the substituents to understand structure-reactivity relationships that are more difficult to achieve with heterogeneous catalysts. Molecular electrocatalysts can be immobilized on surfaces by covalent bonds or through non-covalent interactions. Advantages of surface immobilization include the need for less catalyst, avoidance of bimolecular decomposition pathways, and easier determination of catalyst lifetime. Copper-catalyzed click reactions are often used to form covalent bonds to surfaces, and pi-pi stacking of pyrenemore » substituents appended to the ligand of a molecular complex is a frequently used method to achieve non-covalent surface immobilization. This mini-review highlights surface confinement of molecular electrocatalysts for reduction of O2, oxidation of H2O, production of H2, and reduction of CO2.« less

MEMS CLOSED CHAMBER HEAT ENGINE AND ELECTRIC GENERATOR

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A. (Inventor)

2005-01-01

A heat engine, preferably combined with an electric generator, and advantageously implemented using micro-electromechanical system (MEMS) technologies as an array of one or more individual heat engine/generators. The heat engine is based on a closed chamber containing a motive medium, preferably a gas; means for alternately enabling and disabling transfer of thermal energy from a heat source to the motive medium; and at least one movable side of the chamber that moves in response to thermally-induced expansion and contraction of the motive medium, thereby converting thermal energy to oscillating movement. The electrical generator is combined with the heat engine to utilize movement of the movable side to convert mechanical work to electrical energy, preferably using electrostatic interaction in a generator capacitor. Preferably at least one heat transfer side of the chamber is placed alternately into and out of contact with the heat source by a motion capacitor, thereby alternately enabling and disabling conductive transfer of heat to the motive medium.

Non-PGM cathode catalysts for fuel cell application derived from heat treated heteroatomic amines precursors

DOEpatents

Serov, Alexey; Halevi, Barr; Artyushkova, Kateryna; Atanassov, Plamen B; Martinez, Ulises A

2017-04-25

A method of preparing M-N--C catalysts utilizing a sacrificial support approach and inexpensive and readily available polymer precursors as the source of nitrogen and carbon is disclosed. Exemplary polymer precursors include non-porphyrin precursors with no initial catalytic activity. Examples of suitable non-catalytic non-porphyrin precursors include, but are not necessarily limited to low molecular weight precursors that form complexes with iron such as 4-aminoantipirine, phenylenediamine, hydroxysuccinimide, ethanolamine, and the like.

Process for recycling components of a PEM fuel cell membrane electrode assembly

DOEpatents

Shore, Lawrence [Edison, NJ

2012-02-28

The membrane electrode assembly (MEA) of a PEM fuel cell can be recycled by contacting the MEA with a lower alkyl alcohol solvent which separates the membrane from the anode and cathode layers of the assembly. The resulting solution containing both the polymer membrane and supported noble metal catalysts can be heated under mild conditions to disperse the polymer membrane as particles and the supported noble metal catalysts and polymer membrane particles separated by known filtration means.

Analytical models of Ohmic heating and conventional heating in food processing

NASA Astrophysics Data System (ADS)

Serventi, A.; Bozzoli, F.; Rainieri, S.

2017-11-01

Ohmic heating is a food processing operation in which an electric current is passed through a food and the electrical resistance of the food causes the electric power to be transformed directly into heat. The heat is not delivered through a surface as in conventional heat exchangers but it is internally generated by Joule effect. Therefore, no temperature gradient is required and it origins quicker and more uniform heating within the food. On the other hand, it is associated with high energy costs and its use is limited to a particular range of food products with an appropriate electrical conductivity. Sterilization of foods by Ohmic heating has gained growing interest in the last few years. The aim of this study is to evaluate the benefits of Ohmic heating with respect to conventional heat exchangers under uniform wall temperature, a condition that is often present in industrial plants. This comparison is carried out by means of analytical models. The two different heating conditions are simulated under typical circumstances for the food industry. Particular attention is paid to the uniformity of the heat treatment and to the heating section length required in the two different conditions.

Patent application for a process for production of effective catalysts for polymerization of unsaturated compounds (in German)

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

Ibing, G.

Organic compounds which contain one or more double carbon bonds per molecule frequently display the ability of polymerizing with each other and with other compounds. It is mainly compounds containing peroxide that serve as catalysts for such operations. Examples of recommended substances are hydrogen peroxide, ozone, perbenzoic acid, benzoin peroxide, peroxide-containing ethers, persulfates, etc. It was found that a catalyst of much greater effectiveness in the polymerization of unsaturated compounds can be obtained from one of the previously-known catalysts if the hydrocarbons are processed with lateral-chain substances (e.g., toluene, xylene, ethyl benzene, propyl benzene, diethyl benzene, etc.) in boiling heatmore » with damp air. In this process there develops a small measure of peroxide of previously unknown make-up, which possess outstanding catalytic effectiveness. For production of the catalyst, the aromatics are heated by return-flow cooler and conducted for several hours through an air stream which has been saturated with steam. Oxidation can be undertaken with other substances also; for example, oxygen, ozone, or compounds which give off oxygen. Activation with air, however, is the simplest way and yields the most effective catalyst. Examples of the process are provided.« less

Novel integrated mechanical biological chemical treatment (MBCT) systems for the production of levulinic acid from fraction of municipal solid waste: A comprehensive techno-economic analysis.

PubMed

Sadhukhan, Jhuma; Ng, Kok Siew; Martinez-Hernandez, Elias

2016-09-01

This paper, for the first time, reports integrated conceptual MBCT/biorefinery systems for unlocking the value of organics in municipal solid waste (MSW) through the production of levulinic acid (LA by 5wt%) that increases the economic margin by 110-150%. After mechanical separation recovering recyclables, metals (iron, aluminium, copper) and refuse derived fuel (RDF), lignocelluloses from remaining MSW are extracted by supercritical-water for chemical valorisation, comprising hydrolysis in 2wt% dilute H2SO4 catalyst producing LA, furfural, formic acid (FA), via C5/C6 sugar extraction, in plug flow (210-230°C, 25bar, 12s) and continuous stirred tank (195-215°C, 14bar, 20min) reactors; char separation and LA extraction/purification by methyl isobutyl ketone solvent; acid/solvent and by-product recovery. The by-product and pulping effluents are anaerobically digested into biogas and fertiliser. Produced biogas (6.4MWh/t), RDF (5.4MWh/t), char (4.5MWh/t) are combusted, heat recovered into steam generation in boiler (efficiency: 80%); on-site heat/steam demand is met; balance of steam is expanded into electricity in steam turbines (efficiency: 35%). Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-Healable Electrical Insulation for High Voltage Applications

NASA Technical Reports Server (NTRS)

Williams, Tiffany S.

2017-01-01

Polymeric aircraft electrical insulation normally degrades by partial discharge with increasing voltage, which causes excessive localized Joule heating in the material and ultimately leads to dielectric failure of the insulator through thermal breakdown. Developing self-healing insulation could be a viable option to mitigate permanent mechanical degradation, thus increasing the longevity of the insulation. Instead of relying on catalyst and monomer-filled microcapsules to crack, flow, and cure at the damaged sites described in well-published mechanisms, establishment of ionic crosslinks could allow for multiple healing events to occur with the added benefit of achieving full recovery strength under certain thermal environments. This could be possible if the operating temperature of the insulator is the same as or close to the temperature where ionic crosslinks are formed. Surlyn, a commercial material with ionic crosslinks, was investigated as a candidate self-healing insulator based off prior demonstrations of self-healing behavior. Thin films of varying thicknesses were investigated and the effects of thickness on the dielectric strength were evaluated and compared to representative polymer insulators. The effects of thermal conditioning on the recovery strength and healing were observed as a function of time following dielectric breakdown. Moisture absorption was also studied to determine if moisture absorption rates in Surlyn were lower than that of common polyimides.

Self-organizing intelligent network of smart electrical heating devices as an alternative to traditional ways of heating

NASA Astrophysics Data System (ADS)

Zaslavsky, Aleksander M.; Tkachov, Viktor V.; Protsenko, Stanislav M.; Bublikov, Andrii V.; Suleimenov, Batyrbek; Orshubekov, Nurbek; Gromaszek, Konrad

2017-08-01

The paper considers the problem of automated decentralized distribution of the electric energy among unlimited-power electric heaters providing the given temperature distribution within the zones of monitored object heating in the context of maximum use of electric power which limiting level is time-dependent randomly. Principles of collective selforganization automata for solving the problem are analyzed. It has been shown that after all the automata make decision, equilibrium of Nash type is attained when unused power within the electric network is not more than a power of any non-energized electric heater.

Iron-carbon compacts and process for making them

DOEpatents

Sheinberg, Haskell

2000-01-01

The present invention includes iron-carbon compacts and a process for making them. The process includes preparing a slurry comprising iron powder, furfuryl alcohol, and a polymerization catalyst for initiating the polymerization of the furfuryl alcohol into a resin, and heating the slurry to convert the alcohol into the resin. The resulting mixture is pressed into a green body and heated to form the iron-carbon compact. The compact can be used as, or machined into, a magnetic flux concentrator for an induction heating apparatus.

Investigation of Chirality Selection Mechanism of Single Walled Carbon Nanotube-3

DTIC Science & Technology

2017-12-14

however, several universal and intrinsic problems remain. First, since the dewetting of a thin catalyst film into particles upon heating is a... heated to 800 °C in 15 minutes under Ar atmosphere, maintained for various times, and cooled down to room temperature. - Annealing of Fe-implanted...located 12 cm downstream from the middle of the tube reactor. Then the reactor was heated to 820 °C over 15 min with flowing Ar gas. During the ramping

Undergraduate research studies program at participating institutions of the HBCU Fossil Energy Consortium

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

Bhatia, S.C.; Cardelino, B.H.; Hall, J.H. Jr.

1990-01-31

This report consists of five quarterly progress reports from four participating universities. The titles of the projects are: Competition of NO and SO{sub 2} for OH generated within electrical aerosol analyzers; Dispersed iron catalysts for coal gasification; Catalytic gasification of coal chars by potassium sulfate and ferrous sulfate mixtures; Removal of certain toxic heavy metal ions in coal conversion process wastewaters; and Study of coal liquefaction catalysts. All reports have been indexed separately for inclusion on the data base. (CK)

Mobilization and Defense Management Technical Reports Series. Critical Non-Fuel Minerals in Mobilization with Case Studies on Cobalt and Titanium.

DTIC Science & Technology

1983-04-01

Affairs Comarce Science and Transportation House Comittees Science Rsearch and Tecnology Interstate and Foreign Commrce hnting, Finance, and Urban...cobalt include cutting tools, jet engine parts, electrical devices, permanent magnets, catalysts, paint pigmnts, and paint dryers . 1 The U.S. is the...in the superalloy field. Subtittesfor cobalt as a catalyst or as a dryer in paints are usually not effective. In dryer iUcations,, manganame and lead

High thermal conductivity connector having high electrical isolation

DOEpatents

Nieman, Ralph C.; Gonczy, John D.; Nicol, Thomas H.

1995-01-01

A method and article for providing a low-thermal-resistance, high-electrical-isolation heat intercept connection. The connection method involves clamping, by thermal interference fit, an electrically isolating cylinder between an outer metallic ring and an inner metallic disk. The connection provides durable coupling of a heat sink and a heat source.

Enhanced Electro-Kinetics of C-C Bond-Splitting during Ethanol Oxidation Reaction using Pt/Rh/Sn Catalyst with a Partially Oxidized Pt and Rh Core and a SnO2 Shell

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

Yang, G.; Su, D.; Frenkel, A. I.

Direct ethanol fuel cell (DEFC) is a promising technology for generating electricity via the electro-oxidation of liquid ethanol. Its implementation requires the development of anode catalysts capable of producing CO 2 and yielding 12-electron transfer through breaking C-C bond of ethanol. Here we presented comprehensive studies of electro-kinetics of the CO 2 generation on Pt/Rh/Sn ternary catalysts. Our studies showed that, for the first time, the tri–phase PtRhOx- SnO 2 catalysts with a partially oxidized Pt and Rh core and a SnO 2 shell, validated by X-ray absorption analyses and scanning transmission electron microscope-electron energy loss spectroscopy line scan, coincidedmore » with a 2.5-fold increase in the CO 2 generation rate towards ethanol oxidation reaction, compared with the bi-phase PtRh-SnO 2 catalysts with a metallic PtRh alloy core and commercial Pt. These studies provided insight on the design of a new genre of electro-catalysts with a partially oxidized noble metal.« less

Enhanced Electro-Kinetics of C-C Bond-Splitting during Ethanol Oxidation Reaction using Pt/Rh/Sn Catalyst with a Partially Oxidized Pt and Rh Core and a SnO2 Shell

DOE PAGES

Yang, G.; Su, D.; Frenkel, A. I.; ...

2016-09-04

Direct ethanol fuel cell (DEFC) is a promising technology for generating electricity via the electro-oxidation of liquid ethanol. Its implementation requires the development of anode catalysts capable of producing CO 2 and yielding 12-electron transfer through breaking C-C bond of ethanol. Here we presented comprehensive studies of electro-kinetics of the CO 2 generation on Pt/Rh/Sn ternary catalysts. Our studies showed that, for the first time, the tri–phase PtRhOx- SnO 2 catalysts with a partially oxidized Pt and Rh core and a SnO 2 shell, validated by X-ray absorption analyses and scanning transmission electron microscope-electron energy loss spectroscopy line scan, coincidedmore » with a 2.5-fold increase in the CO 2 generation rate towards ethanol oxidation reaction, compared with the bi-phase PtRh-SnO 2 catalysts with a metallic PtRh alloy core and commercial Pt. These studies provided insight on the design of a new genre of electro-catalysts with a partially oxidized noble metal.« less

Control system for, and a method of, heating an operator station of a work machine

DOEpatents

Baker, Thomas M.; Hoff, Brian D.; Akasam, Sivaprasad

2005-04-05

There are situations in which an operator remains in an operator station of a work machine when an engine of the work machine is inactive. The present invention includes a control system for, and a method of, heating the operator station when the engine is inactive. A heating system of the work machine includes an electrically-powered coolant pump, a power source, and at least one piece of warmed machinery. An operator heat controller is moveable between a first and a second position, and is operable to connect the electrically-powered coolant pump to the power source when the engine is inactive and the operator heat controller is in the first position. Thus, by deactivating the engine and then moving the operator heat controller to the first position, the operator may supply electrical energy to the electrically-powered coolant pump, which is operably coupled to heat the operator station.

Electrically heated DPF start-up strategy

DOEpatents

Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

2012-04-10

An exhaust system that processes exhaust generated by an engine has a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates in the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates. Heat generated by combustion of particulates in the heater induces combustion of particulates within the DPF. A control module selectively enables current flow to the electrical heater for an initial period of a DPF regeneration cycle, and limits exhaust flow while the electrical heater is heating to a predetermined soot combustion temperature.

Apparatus for mounting a diode in a microwave circuit

DOEpatents

Liu, Shing-gong

1976-07-27

Apparatus for mounting a diode in a microwave circuit for making electrical contact between the circuit and ground and for dissipation of heat between the diode and a heat sink. The diode, supported on a thermally and electrically conductive member, is resiliently pressed in electrical contact with the microwave circuit. A tapered collar on the member is elastically deformably wedged into a tapered aperture formed in a heat sink. The wedged collar tightens firmly around the member establishing good thermal and electrical conduction from the diode to the heat sink and ground. Disassembly is facilitated because of the elastically deformed collar.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James R

2014-11-04

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James

2013-12-17

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

Process for photosynthetically splitting water

DOEpatents

Greenbaum, Elias

1984-01-01

The invention is an improved process for producing gaseous hydrogen and oxygen from water. The process is conducted in a photolytic reactor which contains a water-suspension of a photoactive material containing a hydrogen-liberating catalyst. The reactor also includes a volume for receiving gaseous hydrogen and oxygen evolved from the liquid phase. To avoid oxygen-inactivation of the catalyst, the reactor is evacuated continuously by an external pump which circulates the evolved gases through means for selectively recovering hydrogen therefrom. The pump also cools the reactor by evaporating water from the liquid phase. Preferably, product recovery is effected by selectively diffusing the hydrogen through a heated semipermeable membrane, while maintaining across the membrane a magnetic field gradient which biases the oxygen away from the heated membrane. This promotes separation, minimizes the back-reaction of hydrogen and oxygen, and protects the membrane.

Electrochemical durability of heat-treated carbon nanospheres as catalyst supports for proton exchange membrane fuel cells.

PubMed

Lv, Haifeng; Wu, Peng; Wan, Wei; Mu, Shichun

2014-09-01

Carbon nanospheres is wildly used to support noble metal nanocatalysts in proton exchange membrane (PEM) fuel cells, however they show a low resistance to electrochemical corrosion. In this study, the N-doped treatment of carbon nanospheres (Vulcan XC-72) is carried out in ammonia gas. The effect of heating treatment (up to 1000 degrees C) on resistances to electrochemical oxidation of the N-doped carbon nanospheres (HNC) is investigated. The resistance to electrochemical oxidation of carbon supports and stability of the catalysts are investigated with potentiostatic oxidation and accelerated durability test by simulating PEM fuel cell environment. The HNC exhibit a higher resistance to electrochemical oxidation than traditional Vulcan XC-72. The results show that the N-doped carbon nanospheres have a great potential application in PEM fuel cells.

Glossary of Terms

MedlinePlus

... exhaust pipe. • Electrical : Injury is caused by the electricity passing through the body and heating up the ... Physical Therapy The use of heat, light, water, electricity, massage exercise, and radiation to return the patient ...

Low-Heat-Leak Electrical Leads For Cryogenic Systems

NASA Technical Reports Server (NTRS)

Wise, Stephanie A.; Hooker, Matthew W.

1994-01-01

Electrical leads offering high electrical conductivity and low thermal conductivity developed for use in connecting electronic devices inside cryogenic systems to power supplies, signal-processing circuits, and other circuitry located in nearby warmer surroundings. Strip of superconductive leads on ceramic substrate, similar to ribbon cable, connects infrared detectors at temperature of liquid helium with warmer circuitry. Electrical leads bridging thermal gradient at boundary of cryogenic system designed both to minimize conduction of heat from surroundings through leads into system and to minimize resistive heating caused by electrical currents flowing in leads.

Temperature limited heater with a conduit substantially electrically isolated from the formation

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

Vinegar, Harold J; Sandberg, Chester Ledlie

2009-07-14

A system for heating a hydrocarbon containing formation is described. A conduit may be located in an opening in the formation. The conduit includes ferromagnetic material. An electrical conductor is positioned inside the conduit, and is electrically coupled to the conduit at or near an end portion of the conduit so that the electrical conductor and the conduit are electrically coupled in series. Electrical current flows in the electrical conductor in a substantially opposite direction to electrical current flow in the conduit during application of electrical current to the system. The flow of electrons is substantially confined to the insidemore » of the conduit by the electromagnetic field generated from electrical current flow in the electrical conductor so that the outside surface of the conduit is at or near substantially zero potential at 25.degree. C. The conduit may generate heat and heat the formation during application of electrical current.« less

Characteristics of Catalytic Gasification of Natural Coke with H2O in a Fluidized Bed

NASA Astrophysics Data System (ADS)

Lin, L. S.; Zhao, C. S.; Wang, S.; Zhu, G.; Xiang, W. G.

The experimental investigation on gasification characteristics of natural coke from Peicheng, Jiangsu with steam were conducted in a fluidized bed gasifier setup. The effects of several parameters, in terms of the catalyst type, the catalyst mixed manner and the dosage of catalyst over coke on the yield, the components, the heating value of fuel gas and the carbon conversion rate were examined. Results indicate that the fluidized bed gasification technology could overcome the shortcomings of natural coke. Ca-, Fe- and Cu-based nitrates could improve the gasification reaction effectively with a little difference, they could be listed in a descending sequence as follows: Cu-based>Fe-based>Ca-based according to their catalytic effect. The influences of Fe/Ca ratio and Cu/Ca ratio on gasification are similar, gas yield, carbon conversion rate and gas heating value per hour increase as Fe/Ca ratio or Cu/Ca ratio increases, but all of them go up first and then drop with decrease in Fe/Cu ratio. When the dosage of Ca-, Fe- and Cu-based nitrates mixed with the ratio of Ca/Fe/Cu= 10/35/55 is 3%, the best catalytic effect is achieved.

Performance improvement of optical fiber coupler with electric heating versus gas heating.

PubMed

Shuai, Cijun; Gao, Chengde; Nie, Yi; Peng, Shuping

2010-08-20

Gas heating has been widely used in the process of fused biconical tapering. However, as the instability and asymmetric flame temperature of gas heating exist, the performance of the optical devices fabricated by this method was affected. To overcome the problems resulting from gas combustion, an electric heater is designed and manufactured using a metal-ceramic (MoSi(2)) as a heating material. Our experimental data show that the fused-taper machine with an electric heater has improved the performance of optical devices by increasing the consistency of the extinction ratio, excess loss, and the splitting ratio over that of the previous gas heating mode. Microcrystallizations and microcracks were observed at the fused region of the polarization-maintaining (PM) fiber coupler and at the taper region with scanning electron microscopy and atomic force microscopy respectively. The distribution of the microcrystallizations and microcracks are nonuniform along the fiber with gas heating, while their distribution is rather uniform with electric heating. These findings show that the novel optical fiber coupler with an electric heater has improved the performance of optical fiber devices by affecting the consistency of the optical parameters and micromorphology of the surface of PM fiber.

Nuclear qualified in-containment electrical connectors and methods of connecting electrical conductors

NASA Astrophysics Data System (ADS)

Powell, J. G.

1990-07-01

A nuclear qualified in-containment electrical connection is presented that comprises: (1) an insulated, sheathed instrument lead having electrical conductors extending from one end thereof to provide two exposed lead wires; (2) a watertight cable having electrical conducting wires therein and extending from one end of the cable to provide two lead wires therefrom; (3) two butt splice connectors each connecting the ends of respective ones of the lead wires from the instrument lead and cable; (4) a length of heat shrinkable plastic tubing positioned over each butt splice connector and an adjacent portion of a respective lead wire from the cable and heat shrunk into position; and (5) a length of heat shrinkable plastic tubing on the end portion of the instrument lead adjacent the lead wires therefrom, heat shrunk thereon, with a length of outer heat shrinkable plastic tubing. The plastic tubing extends over the end portion of the instrument lead and the heat shrinkable tubing and over the butt splice connectors and a portion of the cable adjacent the cable lead lines. The outer heat shrinkable tubing is heat shrunk into sealing position on the instrument lead and cable.

Acetylene-chromene terminated resins as high temperature thermosets

NASA Technical Reports Server (NTRS)

Godschalx, J. P.; Inbasekaran, M. N.; Bartos, B. R.; Scheck, D. M.; Laman, S. A.

1990-01-01

A novel phase transfer catalyzed process for the preparation of propargyl ethers has been developed. The propargyl ethers serve as precursors to a new class of thermosetting resins called acetylene-chromene terminated (ACT) resins. Heat treatment of a solution of propargyl ethers with various catalysts, followed by removal of solvent leads to the ACT resins via partial conversion of the propargyl ether groups to chromenes. This process reduces the energy content of the resin systems and reduces the amount of shrinkage found during cure. Due to the presence of the solvent the process is safe and gives rise to low viscosity products suitable for resin transfer molding and filament winding type applications. Due to the high glass transition temperature, high modulus, and low moisture uptake the cured resins display better than 232 C/wet performance. The thermal stability of the ACT resins in air at 204 C is superior to that of conventional bismaleimide resins. The resins also display excellent electrical properties.

Heavy-Duty Stoichiometric Compression Ignition Engine with Improved Fuel Economy over Alternative Technologies for Meeting 2010 On-Highway Emission

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

Kirby J. Baumgard; Richard E. Winsor

2009-12-31

The objectives of the reported work were: to apply the stoichiometric compression ignition (SCI) concept to a 9.0 liter diesel engine; to obtain engine-out NO{sub x} and PM exhaust emissions so that the engine can meet 2010 on-highway emission standards by applying a three-way catalyst for NO{sub x} control and a particulate filter for PM control; and to simulate an optimize the engine and air system to approach 50% thermal efficiency using variable valve actuation and electric turbo compounding. The work demonstrated that an advanced diesel engine can be operated at stoichiometric conditions with reasonable particulate and NOx emissions atmore » full power and peak torque conditions; calculated that the SCI engine will operate at 42% brake thermal efficiency without advanced hardware, turbocompounding, or waste heat recovery; and determined that EGR is not necessary for this advanced concept engine, and this greatly simplifies the concept.« less

Research on HOPE communication and data processing equipment

NASA Astrophysics Data System (ADS)

Yamamoto, Satoru; Kikuchi, Toshio

1992-08-01

An overview of the research on heat-resisting antenna is presented. Candidate heat-resisting antennas which were selected as the result of review on seven kinds of antenna are the antennas of micro strip, cavity, and horn types. Heat resistance characteristics of electric power supplying section (connectors) of heat-resisting antenna were studied. Heat cycling test and heat shock tests were conducted on the subject plugs and it was confirmed that they can be usable at - 80 C to + 200 C against - 65 C to + 125 C for the existing plugs. Fundamental electric data such as antenna pattern were acquired mating trial produced components simulating electric characteristics of heat-resisting antenna and trial-produced ceramic tiles.

Methods for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Baird, Lance Awender; Brandvold, Timothy A.

2015-06-30

Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method for deoxygenating a biomass-derived pyrolysis oil comprising the steps of combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-pyoil diluent recycle stream to form a heated diluted pyoil feed stream is provided. The heated diluted pyoil feed stream has a feed temperature of about 150.degree. C. or greater. The heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

Sequential pyrolysis of plastic to recover polystyrene, HCl and terephthalic acid

DOEpatents

Evans, R.J.; Chum, H.L.

1995-11-07

A process is described for pyrolyzing plastic waste feed streams containing polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene to recover polystyrene, HCl and terephthalic acid comprising: heating the plastic waste feed stream to a first temperature; adding an acid or base catalyst on an oxide or carbonate support; heating the plastic waste feed stream to pyrolyze polyethylene terephthalate and polyvinyl chloride; separating terephthalic acid or HCl; heating to a second temperature to pyrolyze polystyrene; separating styrene; heating the waste feed stream to a third temperature to pyrolyze polyethylene; and separating hydrocarbons. 83 figs.

3D CNT macrostructure synthesis catalyzed by MgFe2O4 nanoparticles-A study of surface area and spinel inversion influence

NASA Astrophysics Data System (ADS)

Zampiva, Rúbia Young Sun; Kaufmann Junior, Claudir Gabriel; Pinto, Juliano Schorne; Panta, Priscila Chaves; Alves, Annelise Kopp; Bergmann, Carlos Pérez

2017-11-01

The MgFe2O4 spinel exhibits remarkable magnetic properties that open up numerous applications in biomedicine, the environment and catalysis. MgFe2O4 nanoparticles are excellent catalyst for carbon nanotube (CNT) production. In this work, we proposed to use MgFe2O4 nanopowder as a catalyst in the production of 3D macroscopic structures based on CNTs. The creation of these nanoengineered 3D architectures remains one of the most important challenges in nanotechnology. These systems have high potential as supercapacitors, catalytic electrodes, artificial muscles and in environmental applications. 3D macrostructures are formed due to an elevated density of CNTs. The quantity and quality of the CNTs are directly related to the catalyst properties. A heat treatment study was performed to produce the most effective catalyst. Factors such as superficial area, spinel inversion, crystallite size, degree of agglomeration and its correlation with van der Waals forces were examined. As result, the ideal catalyst properties for CNT production were determined and high-density 3D CNT macrostructures were produced successfully.

An In-Situ XAS Study of the Structural Changes in a CuO-CeO2/Al2O3 Catalyst during Total Oxidation of Propane

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

Silversmith, Geert; Poelman, Hilde; Poelman, Dirk

2007-02-02

A CuOx-CeOx/Al2O3 catalyst was studied with in-situ transmission Cu K XAS for the total oxidation of propane as model reaction for the catalytic elimination of volatile organic compounds. The local Cu structure was determined for the catalyst as such, after pre-oxidation and after reduction with propane. The catalyst as such has a local CuO structure. No structural effect was observed upon heating in He up to 600 deg. C or after pre-oxidation at 150 deg. C. A full reduction of the Cu2+ towards metallic Cu0 occurred, when propane was fed to the catalyst. The change in local Cu structure duringmore » propane reduction was followed with a time resolution of 1 min. The {chi}(k) scans appeared as linear combinations of start and end spectra, CuO and Cu structure, respectively. However, careful examination of the XANES edge spectra indicates the presence of a small amount of additional Cu1+ species.« less

Recent advances on enzymatic glucose/oxygen and hydrogen/oxygen biofuel cells: Achievements and limitations

NASA Astrophysics Data System (ADS)

Cosnier, Serge; J. Gross, Andrew; Le Goff, Alan; Holzinger, Michael

2016-09-01

The possibility of producing electrical power from chemical energy with biological catalysts has induced the development of biofuel cells as viable energy sources for powering portable and implanted electronic devices. These power sources employ biocatalysts, called enzymes, which are highly specific and catalytic towards the oxidation of a biofuel and the reduction of oxygen or hydrogen peroxide. Enzymes, on one hand, are promising candidates to replace expensive noble metal-based catalysts in fuel cell research. On the other hand, they offer the exciting prospect of a new generation of fuel cells which harvest energy from body fluids. Biofuel cells which use glucose as a fuel are particularly interesting for generating electricity to power electronic devices inside a living body. Hydrogen consuming biofuel cells represent an emerging alternative to platinum catalysts due to comparable efficiencies and the capability to operate at lower temperatures. Currently, these technologies are not competitive with existing commercialised fuel cell devices due to limitations including insufficient power outputs and lifetimes. The advantages and challenges facing glucose biofuel cells for implantation and hydrogen biofuel cells will be summarised along with recent promising advances and the future prospects of these exotic energy-harvesting devices.

Process for growing silicon carbide whiskers by undercooling

DOEpatents

Shalek, Peter D.

1987-01-01

A method of growing silicon carbide whiskers, especially in the .beta. form, using a heating schedule wherein the temperature of the atmosphere in the growth zone of a furnace is first heated to or beyond the growth temperature and then is cooled to or below the growth temperature to induce nucleation of whiskers at catalyst sites at a desired point in time which results in the selection.

Development of highly active and stable hybrid cathode catalyst for PEMFCs

NASA Astrophysics Data System (ADS)

Jung, Won Suk

Polymer electrolyte membrane fuel cells (PEMFCs) are attractive power sources of the future for a variety of applications including portable electronics, stationary power, and automobile application. However, sluggish cathode kinetics, high Pt cost, and durability issues inhibit the commercialization of PEMFCs. To overcome these drawbacks, research has been focused on alloying Pt with transition metals since alloy catalysts show significantly improved catalytic properties like high activity, selectivity, and durability. However, Pt-alloy catalysts synthesized using the conventional impregnation method exhibit uneven particle size and poor particle distribution resulting in poor performance and/or durability in PEMFCs. In this dissertation, a novel catalyst synthesis methodology is developed and compared with catalysts prepared using impregnation method and commercial catalysts. Two approaches are investigated for the catalyst development. The catalyst durability was studied under U. S. DRIVE Fuel Cell Tech Team suggested protocols. In the first approach, the carbon composite catalyst (CCC) having active sites for oxygen reduction reaction (ORR) is employed as a support for the synthesis of Pt/CCC catalyst. The structural and electrochemical properties of Pt/CCC catalyst are investigated using high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, while RDE and fuel cell testing are carried out to study the electrochemical properties. The synergistic effect of CCC and Pt is confirmed by the observed high activity towards ORR for the Pt/CCC catalyst. The second approach is the synthesis of Co-doped hybrid cathode catalysts (Co-doped Pt/CCC) by diffusing the Co metal present within the CCC support into the Pt nanoparticles during heat-treatment. The optimized Co-doped Pt/CCC catalyst performed better than the commercial catalysts and the catalyst prepared using the impregnation method in PEMFCs and showed high stability under 30,000 potential cycles between 0.6 and 1.0 V. To further increase the stability of the catalyst at high potential cycles (1.0-1.5 V), high temperature treatment is used to obtain graphitized carbon having optimum BET surface area. The novel catalyst synthesis procedure developed in this study was successfully applied for the synthesis of Co-doped Pt catalysts supported on the graphitized carbon which showed high activity and enhanced stability at high potentials.

Changing Morphology of BaO/AI₂O₃ during NO₂ Uptake and Release

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

Szanyi, Janos; Kwak, Ja Hun; Hanson, Jonathan

2005-04-21

The changes in the morphology of Ba-oxide-based NOx storage/reduction catalysts were investigated using time resolved x-ray diffraction, transmission electron microscopy and energy dispersed spectroscopy. Large Ba(NO₃)₂ crystallites form on the alumina support when the catalyst is prepared by the incipient wetness method using an aqueous Ba(NO₃)₂ solution. Heating the sample to 873K in a He flow results in the decomposition of the Ba(NO₃)₂ phase and the formation of both a monolayer BaO film strongly interacting with the alumina support, and nano crystalline BaO particles. Upon NO₂ exposure of these BaO phases at room temperature, small (nano-sized) Ba(NO₃)₂ crystals and amore » monolayer of surface nitrate form. Heating this sample in NO₂ results in the coalescence of the nano crystalline Ba(NO₃)₂ particles into large crystals. The average crystal size in the re-formed Ba(NO₃)₂ layer is significantly smaller than that measured after the catalyst preparation. Evidence is also presented for the existence of a monolayer Ba(NO₃)₂ phase after thermal treatment in NO₂, in addition to these large crystals. These results clearly demonstrate the dynamic nature of the Ba-containing phases that are active in the NOx storage/reduction process. The proposed morphology cycle may contribute to the understanding of the changes observed in the performances of these catalysts during actual operating conditions.« less

Gold-supported cerium-doped NiO x catalysts for water oxidation

DOE PAGES

Ng, Jia Wei Desmond; García-Melchor, Max; Bajdich, Michal; ...

2016-04-29

Here, the development of high-performance catalysts for the oxygen-evolution reaction (OER) is paramount for cost-effective conversion of renewable electricity to fuels and chemicals. Here we report the significant enhancement of the OER activity of electrodeposited NiO x films resulting from the combined effects of using cerium as a dopant and gold as a metal support. This NiCeO x–Au catalyst delivers high OER activity in alkaline media, and is among the most active OER electrocatalysts yet reported. On the basis of experimental observations and theoretical modelling, we ascribe the activity to a combination of electronic, geometric and support effects, where highlymore » active under-coordinated sites at the oxide support interface are modified by the local chemical binding environment and by doping the host Ni oxide with Ce. The NiCeO x–Au catalyst is further demonstrated in a device context by pairing it with a nickel–molybdenum hydrogen evolution catalyst in a water electrolyser, which delivers 50 mA consistently at 1.5 V over 24 h of continuous operation.« less

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

Yan, Jing; Jeong, Young Gyu, E-mail: ygjeong@cnu.ac.kr

High performance elastomeric electric heating elements were prepared by incorporating various contents of pristine multiwalled carbon nanotube (MWCNT) in polydimethylsiloxane (PDMS) matrix by using an efficient solution-casting and curing technique. The pristine MWCNTs were identified to be uniformly dispersed in the PDMS matrix and the electrical percolation of MWCNTs was evaluated to be at ∼0.27 wt. %, where the electrical resistivity of the MWCNT/PDMS composite films dropped remarkably. Accordingly, the composite films with higher MWCNT contents above 0.3 wt. % exhibit excellent electric heating performance in terms of temperature response rapidity and electric energy efficiency at constant applied voltages. In addition, the composite films,more » which were thermally stable up to 250 °C, showed excellent heating-cooling cyclic performance, which was associated with operational stability in actual electric heating applications.« less

3D noninvasive ultrasound Joule heat tomography based on acousto-electric effect using unipolar pulses: a simulation study

PubMed Central

Yang, Renhuan; Li, Xu; Song, Aiguo; He, Bin; Yan, Ruqiang

2012-01-01

Electrical properties of biological tissues are highly sensitive to their physiological and pathological status. Thus it is of importance to image electrical properties of biological tissues. However, spatial resolution of conventional electrical impedance tomography (EIT) is generally poor. Recently, hybrid imaging modalities combining electric conductivity contrast and ultrasonic resolution based on acouto-electric effect has attracted considerable attention. In this study, we propose a novel three-dimensional (3D) noninvasive ultrasound Joule heat tomography (UJHT) approach based on acouto-electric effect using unipolar ultrasound pulses. As the Joule heat density distribution is highly dependent on the conductivity distribution, an accurate and high resolution mapping of the Joule heat density distribution is expected to give important information that is closely related to the conductivity contrast. The advantages of the proposed ultrasound Joule heat tomography using unipolar pulses include its simple inverse solution, better performance than UJHT using common bipolar pulses and its independence of any priori knowledge of the conductivity distribution of the imaging object. Computer simulation results show that using the proposed method, it is feasible to perform a high spatial resolution Joule heat imaging in an inhomogeneous conductive media. Application of this technique on tumor scanning is also investigated by a series of computer simulations. PMID:23123757

Towards 50% wind electricity in Denmark: Dilemmas and challenges

NASA Astrophysics Data System (ADS)

Bach, Paul-Frederik

2016-05-01

Electricity and heat supply systems are essential contributors to a fossil-free future in Denmark. The combined production of heat and power (CHP) and the production of wind energy are already well developed in Denmark. Combined heat and power covers about 40% of the demand for space heating in Denmark, and the production of wind energy is supposed to exceed 50% of the demand for electricity by 2020. The changing electricity and heat production has some consequences already now: i) Decreasing wholesale prices in Denmark and in other countries. ii) Thermal power plants are closing down. Denmark is no longer self-sufficient with electricity under all conditions. iii) The electricity production pattern does not match the demand pattern. The result is that the neighbouring countries must absorb the variations from wind and solar power. Essential challenges: i) The future of combined heat and power in Denmark is uncertain. ii) Denmark will need new backup capacity for filling the gaps in wind power and solar cell output. iii) Flexible electricity consumers are supposed to contribute to balancing the future power systems. There is still a long way to go before the Smart Grid visions are implemented in large scale. iv) The transformation of the power system will create new risks of power failures.

Method of forming catalyst layer by single step infiltration

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

Gerdes, Kirk; Lee, Shiwoo; Dowd, Regis

Provided herein is a method for electrocatalyst infiltration of a porous substrate, of particular use for preparation of a cathode for a solid oxide fuel cell. The method generally comprises preparing an electrocatalyst infiltrate solution comprising an electrocatalyst, surfactant, chelating agent, and a solvent; pretreating a porous mixed ionic-electric conductive substrate; and applying the electrocatalyst infiltration solution to the porous mixed ionic-electric conductive substrate.

Bifunctional catalysts for upgrading of biomass-derived oxygenates: A review

DOE PAGES

Robinson, Allison M.; Hensley, Jesse E.; Medlin, J. Will

2016-06-21

Deoxygenation is an important reaction in the conversion of biomass-derived oxygenates to fuels and chemicals. A key route for biomass refining involves the production of pyrolysis oil through rapid heating of the raw biomass feedstock. Pyrolysis oil as produced is highly oxygenated, so the feasibility of this approach depends in large part on the ability to selectively deoxygenate pyrolysis oil components to create a stream of high-value finished products. Identification of catalytic materials that are active and selective for deoxygenation of pyrolysis oil components has therefore represented a major research area. One catalyst is rarely capable of performing the differentmore » types of elementary reaction steps required to deoxygenate biomass-derived compounds. For this reason, considerable attention has been placed on bifunctional catalysts, where two different active materials are used to provide catalytic sites for diverse reaction steps. Here, we review recent trends in the development of catalysts, with a focus on catalysts for which a bifunctional effect has been proposed. We summarize recent studies of hydrodeoxygenation (HDO) of pyrolysis oil and model compounds for a range of materials, including supported metal and bimetallic catalysts as well as transition-metal oxides, sulfides, carbides, nitrides, and phosphides. Particular emphasis is placed on how catalyst structure can be related to performance via molecular-level mechanisms. Finally, these studies demonstrate the importance of catalyst bifunctionality, with each class of materials requiring hydrogenation and C-O scission sites to perform HDO at reasonable rates.« less

CO Sensing Performance of a Micro Thermoelectric Gas Sensor with AuPtPd/SnO2 Catalyst and Effects of a Double Catalyst Structure with Pt/α-Al2O3

PubMed Central

Goto, Tomoyo; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

2015-01-01

The CO sensing properties of a micro thermoelectric gas sensor (micro-TGS) with a double AuPtPd/SnO2 and Pt/α-Al2O3 catalyst were investigated. While several nanometer sized Pt and Pd particles were uniformly dispersed on SnO2, the Au particles were aggregated as particles measuring >10 nm in diameter. In situ diffuse reflectance Fourier transform Infrared spectroscopy (DRIFT) analysis of the catalyst showed a CO adsorption peak on Pt and Pd, but no clear peak corresponding to the interaction between CO and Au was detected. Up to 200 °C, CO combustion was more temperature dependent than that of H2, while H2 combustion was activated by repeated exposure to H2 gas during the periodic gas test. Selective CO sensing of the micro-TGS against H2 was attempted using a double catalyst structure with 0.3–30 wt% Pt/α-Al2O3 as a counterpart combustion catalyst. The sensor output of the micro-TGS decreased with increasing Pt content in the Pt/α-Al2O3 catalyst, by cancelling out the combustion heat from the AuPtPd/SnO2 catalyst. In addition, the AuPtPd/SnO2 and 0.3 wt% Pt/α-Al2O3 double catalyst sensor showed good and selective CO detection. We therefore demonstrated that our micro-TGS with double catalyst structure is useful for controlling the gas selectivity of CO against H2. PMID:26694397

Design and cost analysis for an ammonia-based solar thermochemical cavity absorber

NASA Astrophysics Data System (ADS)

Williams, O. M.

1980-01-01

A design and cost analysis is introduced for a solar thermochemical cavity absorber operated at the focus of a tracking paraboloidal concentrator and based on the ammonia dissociation reaction. The absorber design consists of a catalyst-filled nickel alloy tube wound into a spiral forming the inner cavity wall and shaped to match the incident power density profile to the reactor heat requirements. The reactor tube is welded to a coaxial counterflow heat exchanger. The relationships among the power density profile, the reaction thermodynamics and kinetics, and the heat transfer characteristics are examined in detail and it is shown that an installed cost goal of typically 10 U.S. dollars per square meter of solar collector area can be achieved through use of high activity ammonia dissociation catalyst. The optimum absorber size for a given paraboloidal dish area is calculated for a system pressure of 20 MPa and it is shown that a cost effective absorber suitable for 100,000-hr operation would operate at 90% efficiency at 750 C wall temperature.

Fluid cooled electrical assembly

DOEpatents

Rinehart, Lawrence E.; Romero, Guillermo L.

2007-02-06

A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Thermochemical Research Pathways with In Situ and Ex Situ Upgrading of Fast Pyrolysis Vapors

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

Dutta, Abhijit; Sahir, A. H.; Tan, Eric

This report was developed as part of the U.S. Department of Energy’s Bioenergy Technologies Office’s efforts to enable the development of technologies for the production of infrastructure-compatible, cost-competitive liquid hydrocarbon fuels from biomass. Specifically, this report details two conceptual designs based on projected product yields and quality improvements via catalyst development and process integration. It is expected that these research improvements will be made within the 2022 timeframe. The two conversion pathways detailed are (1) in situ and (2) ex situ upgrading of vapors produced from the fast pyrolysis of biomass. While the base case conceptual designs and underlying assumptionsmore » outline performance metrics for feasibility, it should be noted that these are only two of many other possibilities in this area of research. Other promising process design options emerging from the research will be considered for future techno-economic analysis. Both the in situ and ex situ conceptual designs, using the underlying assumptions, project MFSPs of approximately $3.5/gallon gasoline equivalent (GGE). The performance assumptions for the ex situ process were more aggressive with higher distillate (diesel-range) products. This was based on an assumption that more favorable reaction chemistry (such as coupling) can be made possible in a separate reactor where, unlike in an in situ upgrading reactor, one does not have to deal with catalyst mixing with biomass char and ash, which pose challenges to catalyst performance and maintenance. Natural gas was used for hydrogen production, but only when off gases from the process was not sufficient to meet the needs; natural gas consumption is insignificant in both the in situ and ex situ base cases. Heat produced from the burning of char, coke, and off-gases allows for the production of surplus electricity which is sold to the grid allowing a reduction of approximately 5¢/GGE in the MFSP.« less

Multistep continuous-flow synthesis of (R)- and (S)-rolipram using heterogeneous catalysts

NASA Astrophysics Data System (ADS)

Tsubogo, Tetsu; Oyamada, Hidekazu; Kobayashi, Shū

2015-04-01

Chemical manufacturing is conducted using either batch systems or continuous-flow systems. Flow systems have several advantages over batch systems, particularly in terms of productivity, heat and mixing efficiency, safety, and reproducibility. However, for over half a century, pharmaceutical manufacturing has used batch systems because the synthesis of complex molecules such as drugs has been difficult to achieve with continuous-flow systems. Here we describe the continuous-flow synthesis of drugs using only columns packed with heterogeneous catalysts. Commercially available starting materials were successively passed through four columns containing achiral and chiral heterogeneous catalysts to produce (R)-rolipram, an anti-inflammatory drug and one of the family of γ-aminobutyric acid (GABA) derivatives. In addition, simply by replacing a column packed with a chiral heterogeneous catalyst with another column packed with the opposing enantiomer, we obtained antipole (S)-rolipram. Similarly, we also synthesized (R)-phenibut, another drug belonging to the GABA family. These flow systems are simple and stable with no leaching of metal catalysts. Our results demonstrate that multistep (eight steps in this case) chemical transformations for drug synthesis can proceed smoothly under flow conditions using only heterogeneous catalysts, without the isolation of any intermediates and without the separation of any catalysts, co-products, by-products, and excess reagents. We anticipate that such syntheses will be useful in pharmaceutical manufacturing.

Enhanced oxidation of naphthalene using plasma activation of TiO2/diatomite catalyst.

PubMed

Wu, Zuliang; Zhu, Zhoubin; Hao, Xiaodong; Zhou, Weili; Han, Jingyi; Tang, Xiujuan; Yao, Shuiliang; Zhang, Xuming

2018-04-05

Non-thermal plasma technology has great potential in reducing polycyclic aromatic hydrocarbons (PAHs) emission. But in plasma-alone process, various undesired by-products are produced, which causes secondary pollutions. Here, a dielectric barrier discharge (DBD) reactor has been developed for the oxidation of naphthalene over a TiO 2 /diatomite catalyst at low temperature. In comparison to plasma-alone process, the combination of plasma and TiO 2 /diatomite catalyst significantly enhanced naphthalene conversion (up to 40%) and CO x selectivity (up to 92%), and substantially reduced the formation of aerosol (up to 90%) and secondary volatile organic compounds (up to near 100%). The mechanistic study suggested that the presence of the TiO 2 /diatomite catalyst intensified the electron energy in the DBD. Meantime, the energized electrons generated in the discharge activated TiO 2 , while the presence of ozone enhanced the activity of the TiO 2 /diatomite catalyst. This plasma-catalyst interaction led to the synergetic effect resulting from the combination of plasma and TiO 2 /diatomite catalyst, consequently enhanced the oxidation of naphthalene. Importantly, we have demonstrated the effectiveness of plasma to activate the photocatalyst for the deep oxidation of PAH without external heating, which is potentially valuable in the development of cost-effective gas cleaning process for the removal of PAHs in vehicle applications during cold start conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Zone heated diesel particulate filter electrical connection

DOEpatents

Gonze, Eugene V.; Paratore, Jr., Michael J.

2010-03-30

An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.

Note on heat conduction in liquid metals. A comparison of laminar and turbulent flow effects

NASA Astrophysics Data System (ADS)

Talmage, G.

1994-05-01

The difference between heat transfer in liquid metals with electric currents and magnetic fields on the one hand and heat transfer in electrically insulating fluids and in conducting solids on the other is pointed out. Laminar and turbulent flow effects in liquid metal sliding electric contacts for homopolar machines are considered. Large temperature gradients can develop within a small region of liquid metal. A model of a liquid-metal sliding electrical contact is developed and analyzed.

Heat-electrical regeneration way to intensive energy saving in an electric arc furnaces

NASA Astrophysics Data System (ADS)

Kartavtcev, S.; Matveev, S.; Neshporenko, E.

2018-03-01

Energy saving in steel production is of great significance for its large economical scale of 1500 mil t/year and high-energy consumption. Steady trend of last years is an increase of steel production in electric arc furnaces (EAF) with a very high consumption of electricity up to 750 kWh/ton. The intention to reduce so much energy consumption they can reach by many ways. One of such way is a transforming heat energy of liquid steel to electricity and destine it to steel electric arc process. Under certain conditions, it may lead to “zero” consumption of electric power in the process. The development of these conditions leads to the formation of energy-efficient heat schemes, with a minimum electricity consumption from the external network.

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

Heated Goggles

NASA Technical Reports Server (NTRS)

1978-01-01

The electrically heated ski goggles shown incorporate technology similar to that once used in Apollo astronauts' helmet visors, and for the same reason-providing fogfree sight in an activity that demands total vision. Defogging is accomplished by applying heat to prevent moisture condensation. Electric heat is supplied by a small battery built into the h goggles' headband. Heat is spread across the lenses by means of an invisible coating of electrically conductive metallic film. The goggles were introduced to the market last fall. They were designed by Sierracin Corporation, Sylmar, California, specialists in the field of heated transparent materials. The company produces heated windshields for military planes and for such civil aircraft as the Boeing 747, McDonnell Douglas DC-10 and Lockheed L-1011 TriStar.

Solar heated fluidized bed gasification system

NASA Technical Reports Server (NTRS)

Qader, S. A. (Inventor)

1981-01-01

A solar-powered fluidized bed gasification system for gasifying carbonaceous material is presented. The system includes a solar gasifier which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb which surrounds the fluid bed reactor zone. The high heat capacity refractory honeycomb is heated by solar energy focused on the honeycomb by solar concentrator through solar window. The fluid bed reaction zone is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb with the walls of the fluidized bed reactor. Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace is provided for start-up procedures and for supplying heat to the fluid bed reaction zone when adequate supplies of solar energy are not available.

Thermoelectric heat exchange element

DOEpatents

Callas, James J.; Taher, Mahmoud A.

2007-08-14

A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

Effect of Tube Diameter on The Design of Heat Exchanger in Solar Drying system

NASA Astrophysics Data System (ADS)

Husham Abdulmalek, Shaymaa; Khalaji Assadi, Morteza; Al-Kayiem, Hussain H.; Gitan, Ali Ahmed

2018-03-01

The drying of agriculture product consumes a huge fossil fuel rates that demand to find an alternative source of sustainable environmental friendly energy such as solar energy. This work presents the difference between using solar heat source and electrical heater in terms of design aspect. A circular-finned tube bank heat exchanger is considered against an electrical heater used as a heat generator to regenerate silica gel in solar assisted desiccant drying system. The impact of tube diameter on the heat transfer area was investigated for both the heat exchanger and the electrical heater. The fin performance was investigated by determining fin effectiveness and fin efficiency. A mathematical model was developed using MATLAB to describe the forced convection heat transfer between hot water supplied by evacuated solar collector with 70 °C and ambient air flow over heat exchanger finned tubes. The results revealed that the increasing of tube diameter augments the heat transfer area of both heat exchanger and electrical heater. The highest of fin efficiency was around 0.745 and the lowest was around 0.687 while the fin effectiveness was found to be around 0.998.

The influence of local versus global heat on the healing of chronic wounds in patients with diabetes.

PubMed

Petrofsky, Jerrold S; Lawson, Daryl; Suh, Hye Jin; Rossi, Christine; Zapata, Karina; Broadwell, Erin; Littleton, Lindsay

2007-12-01

In a previous study, it was shown that placing a subject with chronic diabetic ulcers in a warm room prior to the use of electrical stimulation dramatically increased the healing rate. However, global heating is impractical in many therapeutic environments, and therefore in the present investigation the effect of global heat versus using a local heat source to warm the wound was investigated. Twenty-nine male and female subjects participated in a series of experiments to determine the healing associated with electrical stimulation with the application of local heat through a heat lamp compared to global heating of the subject in a warm room. Treatment consisted of biphasic electrical stimulation at currents at 20 mA for 30 min three times per week for 4 weeks in either a 32 degrees C room or, with the application of local heat, to raise skin temperature to 37 degrees C. Skin blood flow was measured by a laser Doppler imager. Blood flow increased with either local or global heating. During electrical stimulation, blood flow almost doubled on the outside and on the edge of the wound with a smaller increase in the center of the wound. However, the largest increase in blood flow was in the subjects exposed to global heating. Further, healing rates, while insignificant for subjects who did not receive electrical stimulation, showed 74.5 +/- 23.4% healing with global heat and 55.3 +/- 31.1% healing with local heat in 1 month; controls actually had a worsening of their wounds. The best healing modality was global heat. However, there was still a significant advantage in healing with local heat.

Geothermal heat pumps for heating and cooling

NASA Astrophysics Data System (ADS)

Garg, Suresh C.

1994-03-01

Naval Facilities Engineering Service Center (NFESC) has been tasked by Naval Shore Facilities Energy Office to evaluate the NAS Patuxent River ground-source heat pump (GHP) installation. A large part of a building's energy consumption consists of heating and air conditioning for occupant comfort. The space heating requirements are normally met by fossil-fuel-fired equipment or electric resistance heating. Cooling is provided by either air conditioners or heat pumps, both using electricity as an energy source.

Novel phase of carbon, ferromagnetism, and conversion into diamond

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

Narayan, Jagdish, E-mail: narayan@ncsu.edu; Bhaumik, Anagh

2015-12-07

We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown thatmore » nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp{sup 3} (75%–85%) with the rest being threefold sp{sup 2} bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g{sup −1}. From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing growth times as needed. Subsequent laser pulses can be used to grow nanodiamond into microdiamond and nucleate other nanostructures of diamond on the top of existing microdiamond and create novel nanostructured materials. The microstructural details provide insights into the mechanism of formation of nanodiamond, microdiamond, nanoneedles, microneedles, and single-crystal thin films. This process allows carbon-to-diamond conversion and formation of useful nanostructures and microstructures at ambient temperatures in air at atmospheric pressure on practical and heat-sensitive substrates in a controlled way without need for any catalysts and hydrogen to stabilize sp{sup 3} bonding for diamond formation.« less

Novel phase of carbon, ferromagnetism, and conversion into diamond

NASA Astrophysics Data System (ADS)

Narayan, Jagdish; Bhaumik, Anagh

2015-12-01

We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown that nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp3 (75%-85%) with the rest being threefold sp2 bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g-1. From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing growth times as needed. Subsequent laser pulses can be used to grow nanodiamond into microdiamond and nucleate other nanostructures of diamond on the top of existing microdiamond and create novel nanostructured materials. The microstructural details provide insights into the mechanism of formation of nanodiamond, microdiamond, nanoneedles, microneedles, and single-crystal thin films. This process allows carbon-to-diamond conversion and formation of useful nanostructures and microstructures at ambient temperatures in air at atmospheric pressure on practical and heat-sensitive substrates in a controlled way without need for any catalysts and hydrogen to stabilize sp3 bonding for diamond formation.

Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

NASA Technical Reports Server (NTRS)

1980-01-01

The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

Harvesting dissipated energy with a mesoscopic ratchet

NASA Astrophysics Data System (ADS)

Roche, B.; Roulleau, P.; Jullien, T.; Jompol, Y.; Farrer, I.; Ritchie, D. A.; Glattli, D. C.

2015-04-01

The search for new efficient thermoelectric devices converting waste heat into electrical energy is of major importance. The physics of mesoscopic electronic transport offers the possibility to develop a new generation of nanoengines with high efficiency. Here we describe an all-electrical heat engine harvesting and converting dissipated power into an electrical current. Two capacitively coupled mesoscopic conductors realized in a two-dimensional conductor form the hot source and the cold converter of our device. In the former, controlled Joule heating generated by a voltage-biased quantum point contact results in thermal voltage fluctuations. By capacitive coupling the latter creates electric potential fluctuations in a cold chaotic cavity connected to external leads by two quantum point contacts. For unequal quantum point contact transmissions, a net electrical current is observed proportional to the heat produced.

Thermo-economic analysis of a trigeneration HCPVT power plant

NASA Astrophysics Data System (ADS)

Selviaridis, Angelos; Burg, Brian R.; Wallerand, Anna Sophia; Maréchal, François; Michel, Bruno

2015-09-01

The increasing need for electricity and heat in a growing global economy must be combined with CO2 emissions reduction, in order to limit the human influence on the environment. This calls for energy-efficient and cost-competitive renewable energy systems that are able to satisfy both pressing needs. A High-Concentration Photovoltaic Thermal (HCPVT) system is a cogeneration concept that shows promising potential in delivering electricity and heat in an efficient and cost-competitive manner. This study investigates the transient behavior of the HCPVT system and presents a thermo-economic analysis of a MW-scale trigeneration (electricity, heating and cooling) power plant. Transient simulations show a fast dynamic response of the system which results in short heat-up intervals, maximizing heat recuperation throughout the day. Despite suboptimal coupling between demand and supply, partial heat utilization throughout the year and low COP of commercially available devices for the conversion of heat into cooling, the thermo-economic analysis shows promising economic behavior, with a levelized cost of electricity close to current retail prices.

Thermoelectric as recovery and harvesting of waste heat from portable generator

NASA Astrophysics Data System (ADS)

Mustafa, S. N.; Kamarrudin, N. S.; Hashim, M. S. M.; Bakar, S. A.; Razlan, Z. M.; Harun, A.; Ibrahim, I.; Faizi, M. K.; Saad, M. A. M.; Zunaidi, I.; Wan, W. K.; Desa, H.

2017-10-01

Generation of waste heat was ineluctable especially during energy producing process. Waste heat falls into low temperature grade make it complicated to utilize. Thermoelectric generator (TEG) offers opportunity to harvest any temperature grade heat into useful electricity. This project is covered about recovery and utilizing waste heat from portable electric generator by using a TEG which placed at exhaust surface. Temperature difference at both surfaces of TEG was enhanced with supplying cold air from a wind blower. It is found that, even at low air speed, the TEG was successfully produced electricity with aid from DC-DC booster. Results shows possibility to harvest low temperature grade heat and still exist areas for continual improvement.

Three-dimensional B,N-doped Graphene Foam as a Metal-free Catalyst for Oxygen Reduction Reaction

DTIC Science & Technology

2013-01-01

supplementary information (ESI) available: Raman , and CV curves for glass carbon, GF, B-GF, N-GF and BN-GF in Fig. S1 and S2. See DOI: 10.1039/ c3cp51942b...heating rate of 10 1C in nitrogen. The Raman spectra were collected by the Raman spectroscopy (Renishaw), using 514 nm laser. Electrochemical...oxygen-saturated aqueous solution of 0.1 M KOH for up to 20000 s. As the newly developed 3D metal-free ORR catalysts showed very high electrocatalytic

Systems and Methods for Implementing Robust Carbon Nanotube-Based Field Emitters

NASA Technical Reports Server (NTRS)

Kristof, Valerie (Inventor); Manohara, Harish (Inventor); Toda, Risaku (Inventor)

2015-01-01

Systems and methods in accordance with embodiments of the invention implement carbon nanotube-based field emitters. In one embodiment, a method of fabricating a carbon nanotube field emitter includes: patterning a substrate with a catalyst, where the substrate has thereon disposed a diffusion barrier layer; growing a plurality of carbon nanotubes on at least a portion of the patterned catalyst; and heating the substrate to an extent where it begins to soften such that at least a portion of at least one carbon nanotube becomes enveloped by the softened substrate.

Thermally-enhanced oil recovery method and apparatus

DOEpatents

Stahl, Charles R.; Gibson, Michael A.; Knudsen, Christian W.

1987-01-01

A thermally-enhanced oil recovery method and apparatus for exploiting deep well reservoirs utilizes electric downhole steam generators to provide supplemental heat to generate high quality steam from hot pressurized water which is heated at the surface. A downhole electric heater placed within a well bore for local heating of the pressurized liquid water into steam is powered by electricity from the above-ground gas turbine-driven electric generators fueled by any clean fuel such as natural gas, distillate or some crude oils, or may come from the field being stimulated. Heat recovered from the turbine exhaust is used to provide the hot pressurized water. Electrical power may be cogenerated and sold to an electric utility to provide immediate cash flow and improved economics. During the cogeneration period (no electrical power to some or all of the downhole units), the oil field can continue to be stimulated by injecting hot pressurized water, which will flash into lower quality steam at reservoir conditions. The heater includes electrical heating elements supplied with three-phase alternating current or direct current. The injection fluid flows through the heater elements to generate high quality steam to exit at the bottom of the heater assembly into the reservoir. The injection tube is closed at the bottom and has radial orifices for expanding the injection fluid to reservoir pressure.

Design and Testing of a Thermal Storage System for Electric Vehicle Cabin Heating

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

Wang, Mingyu; WolfeIV, Edward; Craig, Timothy

Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by the traction battery. In very cold climatic conditions, the power required to heat the EV cabin can be of a similar magnitude to that required for propulsion of the vehicle. As a result, the driving range of an EV can be reduced very significantly during winter months, which limits consumer acceptance of EVs and results in increased battery costs tomore » achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The system uses the stored latent heat of an advanced phase change material (PCM) to provide cabin heating. The PCM is melted while the EV is connected to the electric grid for charging of the electric battery, and the stored energy is subsequently transferred to the cabin during driving. To minimize thermal losses when the EV is parked for extended periods, the PCM is encased in a high performance insulation system. The electrical PCM-Assisted Thermal Heating System (ePATHS) was designed to provide enough thermal energy to heat the EV s cabin for approximately 46 minutes, covering the entire daily commute of a typical driver in the U.S.« less

Method of making alkali metal hydrides

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

Pecharsky, Vitalij K.; Gupta, Shalabh; Pruski, Marek

A method is provided for making alkali metal hydrides by mechanochemically reacting alkali metal and hydrogen gas under mild temperature (e.g room temperature) and hydrogen pressure conditions without the need for catalyst, solvent, and intentional heating or cooling.

Recycling of used perfluorosulfonic acid membranes

DOEpatents

Grot, Stephen [Middletown, DE; Grot, Walther [Chadds Ford, PA

2007-08-14

A method for recovering and recycling catalyst coated fuel cell membranes includes dissolving the used membranes in water and solvent, heating the dissolved membranes under pressure and separating the components. Active membranes are produced from the recycled materials.

Engineering catalytic activity via ion beam bombardment of catalyst supports for vertically aligned carbon nanotube growth

NASA Astrophysics Data System (ADS)

Islam, A. E.; Nikolaev, P.; Amama, P. B.; Zakharov, D.; Sargent, G.; Saber, S.; Huffman, D.; Erford, M.; Semiatin, S. L.; Stach, E. A.; Maruyama, B.

2015-09-01

Carbon nanotube growth depends on the catalytic activity of metal nanoparticles on alumina or silica supports. The control on catalytic activity is generally achieved by variations in water concentration, carbon feed, and sample placement on a few types of alumina or silica catalyst supports obtained via thin film deposition. We have recently expanded the choice of catalyst supports by engineering inactive substrates like c-cut sapphire via ion beam bombardment. The deterministic control on the structure and chemistry of catalyst supports obtained by tuning the degree of beam-induced damage have enabled better regulation of the activity of Fe catalysts only in the ion beam bombarded areas and hence enabled controllable super growth of carbon nanotubes. A wide range of surface characterization techniques were used to monitor the catalytically active surface engineered via ion beam bombardment. The proposed method offers a versatile way to control carbon nanotube growth in patterned areas and also enhances the current understanding of the growth process. With the right choice of water concentration, carbon feed and sample placement, engineered catalyst supports may extend the carbon nanotube growth yield to a level that is even higher than the ones reported here, and thus offers promising applications of carbon nanotubes in electronics, heat exchanger, and energy storage.

Catalyst cartridge for carbon dioxide reduction unit

NASA Technical Reports Server (NTRS)

Holmes, R. F. (Inventor)

1973-01-01

A catalyst cartridge, for use in a carbon dioxide reducing apparatus in a life support system for space vehicles, is described. The catalyst cartridge includes an inner perforated metal wall, an outer perforated wall space outwardly from the inner wall, a base plate closing one end of the cartridge, and a cover plate closing the other end of the cartridge. The cover plate has a central aperture through which a supply line with a heater feeds a gaseous reaction mixture comprising hydrogen and carbon dioxide at a temperature from about 1000 to about 1400 F. The outer surfaces of the internal wall and the inner surfaces of the outer wall are lined with a ceramic fiber batting material of sufficient thickness to prevent carbon formed in the reaction from passing through it. The portion of the surfaces of the base and cover plates defined within the inner and outer walls are also lined with ceramic batting. The heated reaction mixture passes outwardly through the inner perforated wall and ceramic batting and over the catalyst. The solid carbon product formes is retained within the enclosure containing the catalyst. The solid carbon product formed is retained within the enclosure containing the catalyst. The water vapor and unreacted carbon dioxide and any intermediate products pass through the perforations of the outer wall.

Process for growing silicon carbide whiskers by undercooling

DOEpatents

Shalek, P.D.

1987-10-27

A method of growing silicon carbide whiskers, especially in the [beta] form, is disclosed using a heating schedule wherein the temperature of the atmosphere in the growth zone of a furnace is first heated to or beyond the growth temperature and then is cooled to or below the growth temperature to induce nucleation of whiskers at catalyst sites at a desired point in time which results in the selection. 3 figs.

Metal phthalocyanine polymers

NASA Technical Reports Server (NTRS)

Achar, B. N.; Fohlen, G. M.; Parker, J. A. (Inventor)

1984-01-01

Metal 4, 4', 4", 4"'=tetracarboxylic phthalocyanines (MPTC) are prepared by reaction of trimellitic anhydride, a salt or hydroxide of the desired metal (or the metal in powdered form), urea and a catalyst. A purer form of MPTC is prepared than heretofore. These tetracarboxylic acids are then polymerized by heat to sheet polymers which have superior heat and oxidation resistance. The metal is preferably a divalent metal having an atomic radius close to 1.35A.

Reexamination of Induction Heating of Primitive Bodies in Protoplanetary Disks

NASA Astrophysics Data System (ADS)

Menzel, Raymond L.; Roberge, Wayne G.

2013-10-01

We reexamine the unipolar induction mechanism for heating asteroids originally proposed in a classic series of papers by Sonett and collaborators. As originally conceived, induction heating is caused by the "motional electric field" that appears in the frame of an asteroid immersed in a fully ionized, magnetized solar wind and drives currents through its interior. However, we point out that classical induction heating contains a subtle conceptual error, in consequence of which the electric field inside the asteroid was calculated incorrectly. The problem is that the motional electric field used by Sonett et al. is the electric field in the freely streaming plasma far from the asteroid; in fact, the motional field vanishes at the asteroid surface for realistic assumptions about the plasma density. In this paper we revisit and improve the induction heating scenario by (1) correcting the conceptual error by self-consistently calculating the electric field in and around the boundary layer at the asteroid-plasma interface; (2) considering weakly ionized plasmas consistent with current ideas about protoplanetary disks; and (3) considering more realistic scenarios that do not require a fully ionized, powerful T Tauri wind in the disk midplane. We present exemplary solutions for two highly idealized flows that show that the interior electric field can either vanish or be comparable to the fields predicted by classical induction depending on the flow geometry. We term the heating driven by these flows "electrodynamic heating," calculate its upper limits, and compare them to heating produced by short-lived radionuclides.

Solar Thermoelectricity via Advanced Latent Heat Storage

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

Olsen, Michele L.; Rea, J.; Glatzmaier, Greg C.

2016-05-31

We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a 'thermalmore » valve,' which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.« less

Solar thermoelectricity via advanced latent heat storage

NASA Astrophysics Data System (ADS)

Olsen, M. L.; Rea, J.; Glatzmaier, G. C.; Hardin, C.; Oshman, C.; Vaughn, J.; Roark, T.; Raade, J. W.; Bradshaw, R. W.; Sharp, J.; Avery, A. D.; Bobela, D.; Bonner, R.; Weigand, R.; Campo, D.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

2016-05-01

We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a "thermal valve," which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.

Electrical assembly having heat sink protrusions

DOEpatents

Rinehart, Lawrence E.; Romero, Guillermo L.

2009-04-21

An electrical assembly, comprising a heat producing semiconductor device supported on a first major surface of a direct bond metal substrate that has a set of heat sink protrusions supported by its second major surface. In one preferred embodiment the heat sink protrusions are made of the same metal as is used in the direct bond copper.

Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

PubMed Central

Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di-Jia

2015-01-01

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A⋅cm−3 at 0.9 V or 450 A⋅cm−3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed. PMID:26261338

Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

DOE PAGES

Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; ...

2015-08-25

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report heremore » a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A∙cm -3 at 0.9 V or 450 A∙cm -3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.« less

Highly efficient nonprecious metal catalyst prepared with metal-organic framework in a continuous carbon nanofibrous network.

PubMed

Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di-Jia

2015-08-25

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A ⋅ cm(-3) at 0.9 V or 450 A ⋅ cm(-3) extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.

Northeastern Summer Electricity Market Alert

EIA Publications

2013-01-01

The National Weather Service declared an excessive-heat warning for much of the Mid-Atlantic and northeastern United States, including major electric markets covering Philadelphia, Boston, Washington, D.C., and New York City. This report highlights the wholesale electricity market activity occurring in response to the higher-than-normal electricity demand caused by the heat wave.

Energetics of Elementary Steps in Catalysis and Their Use to Search for New Catalysts

NASA Astrophysics Data System (ADS)

Wolcott, Christopher A.

We live in a society based upon the mass production of chemicals. Whether it is the fuel in a car, the fertilizers used to make food, or the plastics present in just about everything, these chemicals are so ubiquitous that it is difficult to imagine living in a world without them. Nearly all consumer chemicals are produced through a catalytic process, the vast majority of which are heterogeneous. On top of their current, massive presence, heterogeneous catalysts are also expected to play an important role in new emerging technologies such as fuel cells, hydrogen production, green chemistry, and more. Considering their ubiquity in the present and their potential uses in the future, it is no surprise that improving catalyst performance is a very active area of research. Yet despite their ubiquity, and despite their long history of active study, there remains much which is unknown about the fundamentals of catalysts on surfaces. One of the major gaps is in quantitative understanding of the energetics of elementary steps in catalytic reactions on surfaces. The stability or instability of molecules and molecular fragments adsorbed on surfaces in these elementary steps is KEY to understanding what makes one material an effective catalyst and another less effective. In general, one must use single-crystal model catalysts to produce well-defined adsorbates. Classic studies of the energetics of adsorbates on such surfaces have typically involved techniques (such as temperature programmed desorption or equilibrium adsorption experiments) which limit the types of systems which can be studied to those where adsorption is reversible. For most catalytic intermediates present in these elementary steps, this is not the case. Upon adsorption and heating many molecules fall apart and produce strongly bound adsorbates which further dissociate at higher temperatures, or will not leave the surface until they have reacted with something else. Single crystal adsorption calorimetry (SCAC) is a fairly new technique which allows one to probe the heats of formation of such adsorbates for the first time. In this thesis SCAC is used to study the dissociative adsorption of diiodomethane on Pt(111) to produce adsorbed -CH2 and -CH, and water on Fe 3O4(111) and NiO(111) to produce adsorbed -OH. This work expands the library of adsorbates on transition metal surfaces which has been studied by SCAC, and is among the first ever measurements of molecules on well-defined oxide surfaces using SCAC. These results are compared to density functional theory (DFT) calculations of adsorbate energetics, and their use as computational benchmarks is discussed. A new, universally-applicable method of data analysis for SCAC is also developed which allows for the extraction of heat data even in the presence of complex surface reaction/diffusion dynamics without any need for kinetic modeling as required in previous analysis methods, thus greatly expanding the versatility of SCAC. Finally a new method of computational catalyst screening is presented which uses the concept of degree of rate control to simplify calculations compared to the standard method developed by Jens Norskov's group. It greatly reduces the number of adsorbate energies needed to predict the reaction rate for a new catalyst, and provides greater accuracy when studying materials with similar properties to the reference catalyst used. The Norskov method is more robust when extended to materials that are dissimilar. The new method presented here is thus expected to be an important complimentary tool to Norskov's method for high-throughput computational screening. Taken together, the results presented in this dissertation show the importance of experimental measurements for guiding the development of fast quantum mechanical methods like DFT to more closely approach thru "chemical accuracy" in energetic prediction, and how one could use "chemically accurate" DFT energies to rapidly screen potential catalysts for computational catalyst discovery to advance energy and environmental technologies.

Methods of conditioning direct methanol fuel cells

DOEpatents

Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

2005-11-08

Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

Solid oxide fuel cells fueled with reducible oxides

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

Chuang, Steven S.; Fan, Liang Shih

A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing themore » solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.« less

Sulphated Electric Arc Furnace Slag Asfenton-Like Catalyst for Degradation of Reactive Black 5

NASA Astrophysics Data System (ADS)

Zubir, N. A.; Nasuha, N.; Alrozi, R.

2018-06-01

Sulphated electric arc furnace slag (S-EAFS) was obtained through a facile chemical and thermal treatment method. The S-EAFS was evaluated as a Fenton-like catalyst for the oxidative degradation of reactive black 5 (RB5). The S-EAFS was characterized by XRD, SEM-EDX and nitrogen adsorption analysis. The highest RB5 degradation efficiency obtained in this study was above 90% which was maintained across seven successive cycles with minimum iron leaching. This was achieved at a RB5 concentration of 0.15 gL-1 (50 ppm) with 8 mM of H2O2 and a pH of 4.5. Characterization revealed that the presence of sulphated groups (SO4 2-) within the EAFS improved the surface acidity of the material and corresponded to an increase in the catalytic activity for the degradation of RB5 at mild pH.

Fuel cell system for transportation applications

DOEpatents

Kumar, Romesh; Ahmed, Shabbir; Krumpelt, Michael; Myles, Kevin M.

1993-01-01

A propulsion system for a vehicle having pairs of front and rear wheels and a fuel tank. An electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels is connected to a fuel cell having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate the motor. A partial oxidation reformer is connected both to the fuel tank and to the fuel cell receives hydrogen-containing fuel from the fuel tank and water and air and for partially oxidizing and reforming the fuel with water and air in the presence of an oxidizing catalyst and a reforming catalyst to produce a hydrogen-containing gas. The hydrogen-containing gas is sent from the partial oxidation reformer to the fuel cell negative electrode while air is transported to the fuel cell positive electrode to produce dc power for operating the electric motor.

Fuel cell system for transportation applications

DOEpatents

Kumar, R.; Ahmed, S.; Krumpelt, M.; Myles, K.M.

1993-09-28

A propulsion system is described for a vehicle having pairs of front and rear wheels and a fuel tank. An electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels is connected to a fuel cell having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate the motor. A partial oxidation reformer is connected both to the fuel tank and to the fuel cell and receives hydrogen-containing fuel from the fuel tank and uses water and air for partially oxidizing and reforming the fuel in the presence of an oxidizing catalyst and a reforming catalyst to produce a hydrogen-containing gas. The hydrogen-containing gas is sent from the partial oxidation reformer to the fuel cell negative electrode while air is transported to the fuel cell positive electrode to produce dc power for operating the electric motor. 3 figures.

The effect of heat treatment on the performance of the Ni/(Zr-Sm oxide) catalysts for carbon dioxide methanation

NASA Astrophysics Data System (ADS)

Takano, Hiroyuki; Izumiya, Koichi; Kumagai, Naokazu; Hashimoto, Koji

2011-07-01

The active catalysts for methane formation from the gas mixture of CO 2 + 4H 2 with almost 100% methane selectivity were prepared by reduction of the oxide mixture of NiO and ZrO 2 prepared by calcination of aqueous ZrO 2 sol with Sm(NO 3) 3 and Ni(NO 3) 2. The 50 at%Ni-50 at%(Zr-Sm oxide) catalyst consisting of 50 at%Ni-50 at%(Zr + Sm) with Zr/Sm = 5 calcined at 650 or 800 °C showed the highest activity for methanation. The active catalysts were Ni supported on tetragonal ZrO 2, and the activity for methanation increased by an increase in inclusion of Sm 3+ ions substituting Zr 4+ ions in the tetragonal ZrO 2 lattice as a result of an increase in calcination temperature. However, the increase in calcination temperature decreased BET surface area, metal dispersion and hydrogen uptake due to grain growth. Thus, the optimum calcination temperature existed.

Population and hierarchy of active species in gold iron oxide catalysts for carbon monoxide oxidation

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

He, Qian; Freakley, Simon J.; Edwards, Jennifer K.

The identity of active species in supported gold catalysts for low temperature carbon monoxide oxidation remains an unsettled debate. With large amounts of experimental evidence supporting theories of either gold nanoparticles or sub-nm gold species being active, it was recently proposed that a size-dependent activity hierarchy should exist. Here we study the diverging catalytic behaviors after heat treatment of Au/FeO x materials prepared via co-precipitation and deposition precipitation methods. After ruling out any support effects, the gold particle size distributions in different catalysts are quantitatively studied using aberration corrected scanning transmission electron microscopy (STEM). A counting protocol is developed tomore » reveal the true particle size distribution from HAADF-STEM images, which reliably includes all the gold species present. As a result, correlation of the populations of the various gold species present with catalysis results demonstrate that a size-dependent activity hierarchy must exist in the Au/FeO x catalyst.« less

Population and hierarchy of active species in gold iron oxide catalysts for carbon monoxide oxidation

DOE PAGES

He, Qian; Freakley, Simon J.; Edwards, Jennifer K.; ...

2016-09-27

The identity of active species in supported gold catalysts for low temperature carbon monoxide oxidation remains an unsettled debate. With large amounts of experimental evidence supporting theories of either gold nanoparticles or sub-nm gold species being active, it was recently proposed that a size-dependent activity hierarchy should exist. Here we study the diverging catalytic behaviors after heat treatment of Au/FeO x materials prepared via co-precipitation and deposition precipitation methods. After ruling out any support effects, the gold particle size distributions in different catalysts are quantitatively studied using aberration corrected scanning transmission electron microscopy (STEM). A counting protocol is developed tomore » reveal the true particle size distribution from HAADF-STEM images, which reliably includes all the gold species present. As a result, correlation of the populations of the various gold species present with catalysis results demonstrate that a size-dependent activity hierarchy must exist in the Au/FeO x catalyst.« less

Free-standing ternary NiWP film for efficient water oxidation reaction

NASA Astrophysics Data System (ADS)

Yang, Yunpeng; Zhou, Kuo; Ma, Lili; Liang, Yanqin; Yang, Xianjin; Cui, Zhenduo; Zhu, Shengli; Li, Zhaoyang

2018-03-01

High-efficient catalysts for oxygen evolution reaction (OER) is of great concern in improving energy efficiency for water splitting. Here we report a high-performance OER electrocatalyst of nickel-tungsten-phosphorus (NiWP) film prepared by template method. This free-standing ternary electrocatalyst exhibits a remarkable electrocatalytic activity of OER in alkaline medium due to the synergetic effect among these elements and the good electrical conductivity. The reported NiWP composite catalyst has an overpotential of as low as 0.4 V (vs. RHE) at 30 mA cm-2, better than that of the commercial RuO2 catalyst. Moreover, a small charge transfer resistance of 4.06 Ω and a Tafel slope of 68 mV dec-1 demonstrate the outstanding catalytic activity.

Optimal joule heating of the subsurface

DOEpatents

Berryman, James G.; Daily, William D.

1994-01-01

A method for simultaneously heating the subsurface and imaging the effects of the heating. This method combines the use of tomographic imaging (electrical resistance tomography or ERT) to image electrical resistivity distribution underground, with joule heating by electrical currents injected in the ground. A potential distribution is established on a series of buried electrodes resulting in energy deposition underground which is a function of the resistivity and injection current density. Measurement of the voltages and currents also permits a tomographic reconstruction of the resistivity distribution. Using this tomographic information, the current injection pattern on the driving electrodes can be adjusted to change the current density distribution and thus optimize the heating. As the heating changes conditions, the applied current pattern can be repeatedly adjusted (based on updated resistivity tomographs) to affect real time control of the heating.

Boron-doped diamond synthesized at high-pressure and high-temperature with metal catalyst

NASA Astrophysics Data System (ADS)

Shakhov, Fedor M.; Abyzov, Andrey M.; Kidalov, Sergey V.; Krasilin, Andrei A.; Lähderanta, Erkki; Lebedev, Vasiliy T.; Shamshur, Dmitriy V.; Takai, Kazuyuki

2017-04-01

The boron-doped diamond (BDD) powder consisting of 40-100 μm particles was synthesized at 5 GPa and 1500-1600 °C from a mixture of 50 wt% graphite and 50 wt% Ni-Mn catalyst with an addition of 1 wt% or 5 wt% boron powder. The size of crystal domains of doped and non-doped diamond was evaluated as a coherent scattering region by X-ray diffraction (XRD) and using small-angle neutron scattering (SANS), being ≥180 nm (XRD) and 100 nm (SANS). Magnetic impurities of NiMnx originating from the catalyst in the synthesis, which prevent superconductivity, were detected by magnetization measurements at 2-300 K. X-ray photoelectron spectroscopy, the temperature dependence of the resistivity, XRD, and Raman spectroscopy reveal that the concentration of electrically active boron is as high as (2±1)×1020 cm-3 (0.1 at%). To the best of our knowledge, this is the highest boron content for BDD synthesized in high-pressure high-temperature process with metal catalysts.

Efficient hydrogen evolution by ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam

DOE PAGES

Zhou, Haiqing; Yu, Fang; Huang, Yufeng; ...

2016-09-16

With the massive consumption of fossil fuels and its detrimental impact on the environment, methods of generating clean power are urgent. Hydrogen is an ideal carrier for renewable energy; however, hydrogen generation is inefficient because of the lack of robust catalysts that are substantially cheaper than platinum. Therefore, robust and durable earth-abundant and cost-effective catalysts are desirable for hydrogen generation from water splitting via hydrogen evolution reaction. In this paper, we report an active and durable earth-abundant transition metal dichalcogenide-based hybrid catalyst that exhibits high hydrogen evolution activity approaching the state-of-the-art platinum catalysts, and superior to those of most transitionmore » metal dichalcogenides (molybdenum sulfide, cobalt diselenide and so on). Our material is fabricated by growing ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam. This advance provides a different pathway to design cheap, efficient and sizable hydrogen-evolving electrode by simultaneously tuning the number of catalytic edge sites, porosity, heteroatom doping and electrical conductivity.« less

Efficient hydrogen evolution by ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam

NASA Astrophysics Data System (ADS)

Zhou, Haiqing; Yu, Fang; Huang, Yufeng; Sun, Jingying; Zhu, Zhuan; Nielsen, Robert J.; He, Ran; Bao, Jiming; Goddard, William A., III; Chen, Shuo; Ren, Zhifeng

2016-09-01

With the massive consumption of fossil fuels and its detrimental impact on the environment, methods of generating clean power are urgent. Hydrogen is an ideal carrier for renewable energy; however, hydrogen generation is inefficient because of the lack of robust catalysts that are substantially cheaper than platinum. Therefore, robust and durable earth-abundant and cost-effective catalysts are desirable for hydrogen generation from water splitting via hydrogen evolution reaction. Here we report an active and durable earth-abundant transition metal dichalcogenide-based hybrid catalyst that exhibits high hydrogen evolution activity approaching the state-of-the-art platinum catalysts, and superior to those of most transition metal dichalcogenides (molybdenum sulfide, cobalt diselenide and so on). Our material is fabricated by growing ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam. This advance provides a different pathway to design cheap, efficient and sizable hydrogen-evolving electrode by simultaneously tuning the number of catalytic edge sites, porosity, heteroatom doping and electrical conductivity.

7. VIEW OF THE HOT BED FOR THE CONTINUOUS ELECTRIC ...

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

7. VIEW OF THE HOT BED FOR THE CONTINUOUS ELECTRIC FURNACE HEAT TREATING LINE AT THE HEAT TREATMENT PLANT OF THE DUQUESNE WORKS. - U.S. Steel Duquesne Works, Heat Treatment Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Advances in microreaction technology for portable fuel cell applications: Wall coating of thin catalytic films in microreactors

NASA Astrophysics Data System (ADS)

Bravo Bersano, Jaime Cristian

This research has focused on the need to coat microreactor systems composed of channels in the micron size range of 100 to 1000 mum. The experimental procedures and learning are outlined in terms of slurry and surface preparation requirements which are detailed in the experimental section. This system is motivated and applied to micro methanol steam reformers. Thus, a detailed discussion on the driving motivation is given in the introduction. The low temperatures required for steam-reforming of methanol ˜ 493°K (220°C) make it possible to utilize the reformate as a feed to the fuel cell anode. The group of catalysts that shows the highest activity for methanol steam reforming (SR) at low temperature has composition of CuO/ZnO/Al 2O3, which is also the catalyst used for methanol synthesis. Steam reforming of methanol is a highly endothermic process. Conventional reactor configurations, such as a packed bed reactor, operate in a heat transfer limited mode for this reaction. Using catalyst in packed bed form for portable devices is also not convenient due to high pressure drop and possible channeling of gases in addition to poor heat transfer. A wall-coated catalyst represents a superior geometry since it provides lower pressure drop and ease of manufacturing. Due to their small size, microreactors are especially suited for endothermic reactions whose reactivity depends on the rate of heat input. A brief review on microreaction technology is given with a comprehensive survey for catalyst integration into microreactors for catalytic heterogeneous gas phase reactions. The strength of this research is the model that was developed to coat the interior of micron sized capillaries with coats of CuO/ZnO/Al2O 3 slurries as thick as 25 mum in the dry state. The details of the model are given in terms Taylor's theory and Rayleigh's theory. A model is presented that can predict the coat thickness based on experimental conditions The model combines Taylor's experimental work with Lord Rayleigh's instability theory for annular coatings. The model presented serves as a design tool for microreactor design. The model can also estimate the maximum coat thickness possible for a given system. The results are presented in graphical format in the Microchannel Coating Model chapter.

Liquid air cycle engines

NASA Technical Reports Server (NTRS)

Rosevear, Jerry

1992-01-01

Given here is a definition of Liquid Air Cycle Engines (LACE) and existing relevant technologies. Heat exchanger design and fabrication techniques, the handling of liquid hydrogen to achieve the greatest heat sink capabilities, and air decontamination to prevent heat exchanger fouling are discussed. It was concluded that technology needs to be extended in the areas of design and fabrication of heat exchangers to improve reliability along with weight and volume reductions. Catalysts need to be improved so that conversion can be achieved with lower quantities and lower volumes. Packaging studies need to be investigated both analytically and experimentally. Recycling with slush hydrogen needs further evaluation with experimental testing.

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

49 CFR 1248.101 - Commodity codes required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Hardware. 343 Plumbing Fixtures and Heating Apparatus, Except Electric. 3433 Heating equipment, except electric. 344 Fabricated structural metal products. 3441 Fabricated structural metal products. 345 Bolts... fabricated pipe fittings. 35 Machinery, Except Electrical. 351 Engines and Turbines. 352 Farm Machinery and...

Induction heating apparatus and methods for selectively energizing an inductor in response to a measured electrical characteristic that is at least partially a function of a temperature of a material being heated

DOEpatents

Richardson, John G.; Morrison, John L.; Hawkes, Grant L.

2006-07-04

An induction heating apparatus includes a measurement device for indicating an electrical resistance of a material to be heated. A controller is configured for energizing an inductor in response to the indicated resistance. An inductor may be energized with an alternating current, a characteristic of which may be selected in response to an indicated electrical resistance. Alternatively, a temperature of the material may be indicated via measuring the electrical resistance thereof and a characteristic of an alternating current for energizing the inductor may be selected in response to the temperature. Energizing the inductor may minimize the difference between a desired and indicated resistance or the difference between a desired and indicated temperature. A method of determining a temperature of at least one region of at least one material to be induction heated includes correlating a measured electrical resistance thereof to an average temperature thereof.

Effects of an Inhomogenous Electric Field on an Evaporating Thin Film in a Microchannel

NASA Astrophysics Data System (ADS)

Liu, Xiuliang; Hu, Chen; Li, Huafeng; Yu, Fei; Kong, Xiaming

2018-03-01

In this paper, heat transfer enhancement in an evaporating thin film along the wall of a microchannel under an imposed inhomogenous electrostatic field is analyzed. The mathematical model, based on the augmented Young-Laplace equation with the inhomogenous electrostatic field taken into consideration, is developed. The 2D inhomogenous electric field with the curved liquid-vapor interface is solved by the lattice Boltzmann method. Numerical solutions for the thin film characteristics are obtained for both constant wall temperature and uniform wall heat flux boundary conditions. The numerical results show that the liquid film becomes thinner and the heat transfer coefficient increases under an imposed electric field. Both of octane and water are chosen as the working mediums, and similar result about the enhancement of heat transfer on evaporating thin film by imposing electric field is obtained. It is found that applying an electric field on the evaporating thin film can enhance evaporative heat transfer in a microchannel.

Reducing residential solid fuel combustion through electrified space heating leads to substantial air quality, health and climate benefits in China's Beijing-Tianjin-Hebei region

NASA Astrophysics Data System (ADS)

Yang, J.; Mauzerall, D. L.

2017-12-01

During periods of high pollution in winter, household space heating can contribute more than half of PM2.5 concentrations in China's Beijing-Tianjin-Hebei (BTH) region. The majority of rural households and some urban households in the region still heat with small stoves and solid fuels such as raw coal, coal briquettes and biomass. Thus, reducing emissions from residential space heating has become a top priority of the Chinese government's air pollution mitigation plan. Electrified space heating is a promising alternative to solid fuel. However, there is little analysis of the air quality and climate implications of choosing various electrified heating devices and utilizing different electricity sources. Here we conduct an integrated assessment of the air quality, human health and climate implications of various electrified heating scenarios in the BTH region using the Weather Research and Forecasting model with Chemistry. We use the Multi-resolution Emission Inventory for China for the year 2012 as our base case and design two electrification scenarios in which either direct resistance heaters or air source heat pumps are installed to replace all household heating stoves. We initially assume all electrified heating devices use electricity from supercritical coal-fired power plants. We find that installing air source heat pumps reduces CO2 emissions and premature deaths due to PM2.5 pollution more than resistance heaters, relative to the base case. The increased health and climate benefits of heat pumps occur because they have a higher heat conversion efficiency and thus require less electricity for space heating than resistance heaters. We also find that with the same heat pump installation, a hybrid electricity source (40% of the electricity generated from renewable sources and the rest from coal) further reduces both CO2 emissions and premature deaths than using electricity only from coal. Our study demonstrates the air pollution and CO2 mitigation potential and public health benefits of using electrified space heating. In particular, we find air source heat pumps could bring more climate and health benefits than direct resistance heaters. Our results also support policies to integrate renewable energy sources with the reduction of solid fuel combustion for residential space heating.

Germanium Resistance Thermometer For Subkelvin Temperatures

NASA Technical Reports Server (NTRS)

Castles, Stephen H.

1993-01-01

Improved germanium resistance thermometer measures temperatures as small as 0.01 K accurately. Design provides large area for electrical connections (to reduce electrical gradients and increase sensitivity to changes in temperatures) and large heat sink (to minimize resistance heating). Gold pads on top and bottom of germanium crystal distribute electrical current and flow of heat nearly uniformly across crystal. Less expensive than magnetic thermometers or superconducting quantum interference devices (SQUID's) otherwise used.

Ion heating and characteristics of ST plasma used by double-pulsing CHI on HIST

NASA Astrophysics Data System (ADS)

Hanao, Takafumi; Hirono, Hidetoshi; Hyobu, Takahiro; Ito, Kengo; Matsumoto, Keisuke; Nakayama, Takashi; Oki, Nobuharu; Kikuchi, Yusuke; Fukumoto, Naoyuki; Nagata, Masayoshi

2013-10-01

Multi-pulsing Coaxial Helicity Injection (M-CHI) is an efficient current drive and sustainment method used in spheromak and spherical torus (ST). We have observed plasma current/flux amplification by double pulsing CHI. Poloidal ion temperature measured by Ion Doppler Spectrometer (IDS) has a peak at plasma core region. In this region, radial electric field has a negative peak. At more inboard side that is called separatrix between closed flux region and inner open flux region, poloidal flow has a large shear and radial electric field changes the polarity. After the second CHI pulse, we observed sharp and rapid ion heating at plasma core region and separatrix. In this region, the poloidal ion temperature is selective heating because electron temperature is almost uniform. At this time, flow shear become larger and radial electric field is amplified at separatorix. These effects produce direct heating of ion through the viscous flow damping. Furthermore, we observed decrease of electron density at separatrix. Decreased density makes Hall dynamo electric field as two-fluid effect. When the ion temperature is increasing, dynamo electric field is observed at separatrix. It may have influence with the ion heating. We will discuss characteristic of double pulsing CHI driven ST plasmas and correlation of direct heating of ion with dynamo electric field and any other parameters.

Development of attrition resistant iron-based Fischer-Tropsch catalysts

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

NONE

2000-09-20

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. The use of iron-based catalysts is attractive not only due to their low cost and ready availability, but also due to their high water-gas shift activity which makes it possible to use these catalysts with low H{sub 2}/CO ratios. However, a serious problem with use ofmore » Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, makes the separation of catalyst from the oil/wax product very difficult if not impossible, and results a steady loss of catalyst from the reactor. The objective of this research is to develop robust iron-based Fischer-Tropsch catalysts that have suitable activity, selectivity and stability to be used in the slurry bubble column reactor. Specifically we aim to develop to: (1) improve the performance and preparation procedure of the high activity, high attrition resistant, high alpha iron-based catalysts synthesized at Hampton University (2) seek improvements in the catalyst performance through variations in process conditions, pretreatment procedures and/or modifications in catalyst preparation steps and (3) investigate the performance in a slurry reactor. The effort during the reporting period has been devoted to effects of pretreating procedures, using H{sub 2}, CO and syngas (H{sub 2}/CO = 0.67) as reductants, on the performance (activity, selectivity and stability with time) of a precipitated iron catalyst (100Fe/5Cu/4.2K/10SiO{sub 2} on a mass basis ) during F-T synthesis were studied in a fixed-bed reactor.« less

Our Roads, A Large Thermoelectric Generator

NASA Astrophysics Data System (ADS)

Weiss, I.

2017-12-01

If asphalt can heat up from the solar radiation shining onto it directly, then it will be able to heat water in pipes within the pavement. The heat from the warm water can then be harvested into usable electrical energy, because heat energy can be transformed into electrical energy using the Seebeck Effect. The Seebeck Effect is when a temperature difference causes electrons to move away from the heat, creating an electrical charge. My experiment showed my research-based hypothesis correct. I hypothesized that if asphalt can heat up from the solar radiation shining onto it directly, then it would be able to warm a water system and usable energy could be harvested, because heat energy can be transformed into electrical energy. Asphalt pavement does not reflect the sunlight and hence heats up faster than a light surface that would reflect the sunlight. This means the asphalt absorbs the sunlight and gives off heat, which is wasted energy. By turning heat energy into electricity, cities can provide a source of clean, green energy and reduce their reliance on fossil fuels. The heat given off by asphalt increases the temperature of the air around, contributing to what is known as the urban heat island effect. This heating contributes to the formation of smog and ozone depletion. With the population still growing this would mean increasing city sizes, greater heat island effect and hence an increase in smog and ozone depletion. By harvesting the heat energy in the pavement through my setup, cities can not only create green energy but also reduce the heat radiated from pavement. Converting my system to a neighborhood street would produce higher output. My street measures 800 feet long by 35 feet wide. That gives us 28,000 square feet. At the rate of 5 volts per minute for a 2 square foot area, my street would be able to produce 70,000 volts per minute.

Autothermal Processing of Renewable Liquids

NASA Astrophysics Data System (ADS)

Kruger, Jacob Scott

The vast majority of petrochemicals are synthesized from just six building block molecules, but current feedstocks are an unsustainable resource with negative externalities. Biomass represents a potentially sustainable feedstock, but needs densification, preferably to a liquid form, to be a suitable replacement. Fermentation to butanol and pyrolysis to bio-oil are two promising liquid intermediates. Catalytic partial oxidation (CPO) of the liquid intermediates over noble metal catalysts, which converts the liquids primarily into syngas and light olefins, is a promising technique for processing densified biomass. The study of liquids at high temperatures requires consideration of a range of complex phenomena, including boiling behavior on hot surfaces, reactions of the feed molecules at high temperatures and on catalyst surfaces, and interactions of impurities in the liquid with the catalyst. Chapter 2 deals with the behavior of the transient liquid that forms when cellulose, a major constituent of biomass, is pyrolized. Fast photography experiments and numerical simulations are performed to show that the aerosols formed in the boiling of this liquid are capable of transporting nonvolatile fragments of biomass intact into the gas phase. These nonvolatile fragments have significant implications in the storage and downstream processing of bio-oil. Some of the behavior of bio-oil at high temperature may also be explained by the variety of molecules in the liquid. Many different functional groups are present, each with its own set of chemical reactions in combustion, pyrolysis, and partial oxidation on a metal catalyst. Chapters 3 and 4 investigate these reactions through a survey of two-carbon surrogates of the functional group classes found in bio-oil. Chapter 3 examines reactions occuring in the complete CPO system over Pt and Rh catalysts, and in the complete system absent O 2. The selectivity data from each molecule and the surface science literature of each molecule are used to propose a reaction mechanism over the catalyst surface. Chapter 4 investigates the reactions that may be occurring in the gas phase and over the alpha-Al2O3 foam monolith support. Significant gas-phase chemistry is likely present in the autothermal reactor, although different temperature gradients between the autothermal reactions and the externally heated tube makes quantification of the amount of homogeneous chemistry in the autothermal system impossible. The alpha-Al2O 3 support may serve as a heat transfer medium and radical quencher (due to its foam structure with small-diameter pores), but not likely acid catalysis, as selectivity to dehydration products was similar both with and without the foam support. Because butanol is another promising liquid intermediate in biomass processing, a series of experiments with butanol in an CPO reactor was also carried out. Chapter 5 compares the four butanol isomers in a CPO reactor over Pt, PtCe, Rh, and RhCe catalysts. The reactivity of tert-butanol was as high or higher than the other alcohols, indicating that the lack of a carbonyl decomposition path does not necessarily in uence the reactivity of the molecule. Rather, the reactivity appeared to be more a function of the initial pyrolysis temperature of the alcohol. Thus, much of the initial chemistry of the higher alcohols in a CPO reactor may be homogeneous. The main function of the catalyst may be to decompose the intermediate carbonyls and alkenes to syngas. To that end, the PtCe had significantly lower reforming activity than the other catalysts, evidenced by the lower selectivity to CO and H2 and generally higher temperatures. Selectivity to syngas and light olefins was high and tunable depending on feed ratios, indicating the potential of CPO to provide petrochemical building blocks from butanol. Chapter 6 combines CPO with a water-gas shift (WGS) stage and investigates the addition of steam to isobutanol for the production of a high-purity H2 stream. A RhCe catalyst was used in the CPO stage to convert 100% of the isobutanol feed to primarily equilibrium products, although a non-negligible fraction of intermediate isobutryaldehyde, propylene and isobutene. The use of a PtCe catalyst directly downstream allowed the incorporation of a high-temperature WGS stage with no external heat addition. Concentration of CO in the exit stream ≤ 3%, and H2 selectivity ≥ 100% (based on H from isobutanol) was achieved, similar to industrial high-temperature WGS operations. Additionally, the use of a PtCe WGS catalyst allowed conversion of intermediate products remaining from the CPO stage, indicating the robustness of the CPO-WGS system. Finally, because any feedstock intended to produce petrochemical feedstocks will contain impurities, Chapter 7 investigates the durability of a RhCe catalyst over several hundred hours with CPO of food-grade glycerol. This feedstock contains ppm levels of Fe and several other impurities. Despite several perturbations to the system and the addition of impurity levels comparable to catalyst loading by the end of the test, the catalyst maintained 100% conversion of glycerol to equilibrium products throughout the experiment, although some loss of WGS activity was observed. In Chapter 8, several experiments are proposed to strengthen the conclusions of the experiments described in the previous chapters, including co-feeding of radicalscavenging molecules, in-situ spectroscopic studies, and mechanism validation with the current data. Further study of boiling phenomena is also proposed, and some preliminary results are presented. Additionally, integration of photochemistry into a CPO reactor is proposed as a method of improving catalyst durability for processing particularly recalcitrant feedstocks. The ability of CPO to handle high-moisture feedstocks may allow for its use in processing aquatic biomass; a potential design for a photobioreactor for algae cultivation with integration of a CPO reactor is described. Finally, the study of ethanol conversion to butanol through a Guerbet-type reaction is proposed. A Guerbet stage would function particularly well downstream of a CPO reactor because it requires heat, dehydrogenated alcohols, and H 2 addition. Although a comprehensive understanding of the phenomena occuring in a CPO reactor is far from available, the diversity of applications in which sustainably produced syngas and heat find use suggests that CPO reaction engineering is an important area of research. This thesis offers preliminary insight into some of the phenomena and applications of catalytic partial oxidation.

Electricity generation from synthesis gas by microbial processes: CO fermentation and microbial fuel cell technology.

PubMed

Kim, Daehee; Chang, In Seop

2009-10-01

A microbiological process was established to harvest electricity from the carbon monoxide (CO). A CO fermenter was enriched with CO as the sole carbon source. The DGGE/DNA sequencing results showed that Acetobacterium spp. were enriched from the anaerobic digester fluid. After the fermenter was operated under continuous mode, the products were then continuously fed to the microbial fuel cell (MFC) to generate electricity. Even though the conversion yield was quite low, this study proved that synthesis gas (syn-gas) can be converted to electricity with the aid of microbes that do not possess the drawbacks of metal catalysts of conventional methods.

Installation package maxi-therm S-101 heating module

NASA Technical Reports Server (NTRS)

1977-01-01

The installation, operation and maintenance of the Maxi-Therm S-101 Thermosypnon Heating Module is described. The Maxi-Therm S-101 is a packaged unit, complete with air filter, blower, electrical controls, and a thermosyphon liquid to air heat exchanger. It is intended for use in residential solar heating systems and can utilize off-peak electrical power.

Determination of thermophysical characteristics of solid materials by electrical modelling of the solutions to the inverse problems in nonsteady heat conduction

NASA Technical Reports Server (NTRS)

Kozdoba, L. A.; Krivoshei, F. A.

1985-01-01

The solution of the inverse problem of nonsteady heat conduction is discussed, based on finding the coefficient of the heat conduction and the coefficient of specific volumetric heat capacity. These findings are included in the equation used for the electrical model of this phenomenon.

Trash Compactor

NASA Technical Reports Server (NTRS)

1978-01-01

The electrically heated ski goggles shown incorporate technology similar to that once used in Apollo astronauts' helmet visors, and for the same reason-providing fog-free sight in an activity that demands total vision. Defogging is accomplished by applying heat to prevent moisture condensation. Electric heat is supplied by a small battery built into the h goggles' headband. Heat is spread across the lenses by means of an invisible coating of electrically conductive metallic film. The goggles were introduced to the market last fall. They were designed by Sierracin Corporation, Sylmar, California, specialists in the field of heated transparent materials. The company produces heated windshields for military planes and for such civil aircraft as the Boeing 747, McDonnell Douglas DC-10 and Lockheed L-1011 TriStar.

Microcalorimetric, {sup 13}C NMR spectroscopic, and reaction kinetic studies of silica- and L-zeolite-supported platinum catalysts for n-hexane conversion

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

Sharma, S.B.; Ouraipryvan, P.; Nair, H.A.

Reaction kinetics measurement of n-hexane conversion over 4% Pt/SiO{sub 2} and 1% Pt/SiO{sub 2} and 1% Pt/K(Ba)-L catalysts were made at a pressure of 3 atm and temperatures from 698 to 750 K. The rates of benzene and methylcyclopentane formation decrease with time during reaction over Pt/SiO{sub 2}, while 1% Pt/K(Ba)-L does not deactivate significantly. Microcalorimetric measurements at 353 K show that the heat of carbon monoxide adsorption is the same on freshly reduced Pt/SiO{sub 2} and Pt/K(Ba)-L catalysts; however, carbonaceous species that accumulate on Pt/SiO{sub 2} during n-hexane conversion decrease the total number of adsorption sites and the numbermore » of sites that adsorb carbon monoxide strongly. The 1% Pt/K(Ba)-L catalyst retains the adsorptive properties of the freshly reduced catalyst. Nuclear magnetic resonance studies of {sup 13}CO adsorption show that cluster-sized platinum particles are more resistant to deactivation by self-poisoning reactions than larger platinum particles. The greater catalyst stability and higher steady-state activity of L-zeolite-supported platinum catalysts may be attributed to the ability of L-zeolite to stabilize cluster-sized particles under reaction conditions. Differences in dehydrocyclization activity between catalysts may be related to differences in the number of strong adsorption sites that are present under reaction conditions. 31 refs., 7 figs., 4 tabs.« less

Development status of a sealed bipolar lead/acid battery for high-power battery applications

NASA Astrophysics Data System (ADS)

Arias, J. L.; Rowlette, J. J.; Drake, E. D.

A sealed bipolar lead/acid (SBLA) battery is being developed by Arias Research Associates (ARA) which will offer a number of important advantages in applications requiring high power densities. These applications include electric vehicles (EVs) and hybrid electric vehicles, uninterruptable power supplies (UPS), electrically-heated catalysts (EHCs) for automobiles, utility-power peak-shaving, and others. The advantages of the SBLA over other types of batteries will by significantly higher power density, together with good energy density, high cycle life, high voltage density, low production cost and zero maintenance. In addition, the lead/acid battery represents a technology which is familiar and accepted by Society, is recyclable within the existing infrastructure, and does not raise the safety concerns of many other new batteries (e.g., fire, explosion and toxic gases). This paper briefly reviews the basic design concepts and issues of the SBLA battery technology, various quasi-bipolar approaches and the results of ARA's development work during the past four years. Performance data are given based on both in-house and independent testing of ARA laboratory test batteries. In addition, performance projections and other characteristics are given for three ARA SBLA battery designs, which are compared with other batteries in three example applications: UPS, EHCs, and EVs. The most notable advantages of the SBLA battery are substantial reductions in product size and weight for the UPS, smaller packaging and longer life for the EHC, and higher vehicle performance and lower cost for the EV, compared to both existing and advanced EV batteries.

Relating adatom emission to improved durability of Pt-Pd diesel oxidation catalysts

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

Johns, Tyne Richele; Goeke, Ronald S.; Ashbacher, Valerie

Sintering of nanoparticles is an important contributor to loss of activity in heterogeneous catalysts, such as those used for controlling harmful emissions from automobiles. But mechanistic details, such as the rates of atom emission or the nature of the mobile species, remain poorly understood. Herein we report a novel approach that allows direct measurement of atom emission from nanoparticles. We use model catalyst samples and a novel reactor that allows the same region of the sample to be observed after short-term heat treatments (seconds) under conditions relevant to diesel oxidation catalysts (DOCs). Monometallic Pd is very stable and does notmore » sinter when heated in air (T ≤ 800 °C). Pt sinters readily in air, and at high temperatures (≥800 °C) mobile Pt species emitted to the vapor phase cause the formation of large, faceted particles. In Pt–Pd nanoparticles, Pd slows the rate of emission of atoms to the vapor phase due to the formation of an alloy. However, the role of Pd in Pt DOCs in air is quite complex: at low temperatures, Pt enhances the rate of Pd sintering (which otherwise would be stable as an oxide), while at higher temperature Pd helps to slow the rate of Pt sintering. DFT calculations show that the barrier for atom emission to the vapor phase is much greater than the barrier for emitting atoms to the support. Thus, vapor-phase transport becomes significant only at high temperatures while diffusion of adatoms on the support dominates at lower temperatures.« less

Relating adatom emission to improved durability of Pt-Pd diesel oxidation catalysts

DOE PAGES

Johns, Tyne Richele; Goeke, Ronald S.; Ashbacher, Valerie; ...

2015-06-05

Sintering of nanoparticles is an important contributor to loss of activity in heterogeneous catalysts, such as those used for controlling harmful emissions from automobiles. But mechanistic details, such as the rates of atom emission or the nature of the mobile species, remain poorly understood. Herein we report a novel approach that allows direct measurement of atom emission from nanoparticles. We use model catalyst samples and a novel reactor that allows the same region of the sample to be observed after short-term heat treatments (seconds) under conditions relevant to diesel oxidation catalysts (DOCs). Monometallic Pd is very stable and does notmore » sinter when heated in air (T ≤ 800 °C). Pt sinters readily in air, and at high temperatures (≥800 °C) mobile Pt species emitted to the vapor phase cause the formation of large, faceted particles. In Pt–Pd nanoparticles, Pd slows the rate of emission of atoms to the vapor phase due to the formation of an alloy. However, the role of Pd in Pt DOCs in air is quite complex: at low temperatures, Pt enhances the rate of Pd sintering (which otherwise would be stable as an oxide), while at higher temperature Pd helps to slow the rate of Pt sintering. DFT calculations show that the barrier for atom emission to the vapor phase is much greater than the barrier for emitting atoms to the support. Thus, vapor-phase transport becomes significant only at high temperatures while diffusion of adatoms on the support dominates at lower temperatures.« less

Three dimensional metal/N-doped nanoplate carbon catalysts for oxygen reduction, the reason for using a layered nanoreactor.

PubMed

Yeganeh Ghotbi, Mohammad; Javanmard, Arash; Soleimani, Hassan

2018-02-21

A layered nanoreactor (zinc hydroxide gallate/nitrate nanohybrid) has been designed as a nano-vessel to confine the gallate/nitrate reaction inside zinc hydroxide layers for production of metal/nitrogen-doped carbon catalysts. Metals (Fe 2+ , Co 2+ and Ni 2+ ) doped and bare zinc hydroxide nitrates (ZHN) were synthesized as the α-phase hydroxide hosts. By an incomplete ion-exchange process, nitrate anions between the layers of the hosts were then partially replaced by the gallate anions to produce the layered nanoreactors. Under heat-treatment, the reaction between the remaining un-exchanged nitrate anions and the organic moiety inside the basal spacing of each nanohybrid plate resulted in obtaining highly porous 3D metal/nitrogen-doped carbon nanosheets. These catalysts were then used as extremely efficient electrocatalysts for catalyzing oxygen reduction reaction (ORR). This study is intended to show the way to get maximum electrocatalytic activity of the metal/N-doped carbon catalysts toward the ORR. This exceptionally high ORR performance originates from the increased available surface, the best pore size range and the uniform distribution of the active sites in the produced catalysts, all provided by the use of new idea of the layered nanoreactor.

Comparison of non-catalytic and catalytic fast pyrolysis of corncob in a fluidized bed reactor.

PubMed

Zhang, Huiyan; Xiao, Rui; Huang, He; Xiao, Gang

2009-02-01

Fast pyrolysis of corncob with and without catalyst was investigated in a fluidized bed to determine the effects of pyrolysis parameters (temperature, gas flow rate, static bed height and particle size) and a HZSM-5 zeolite catalyst on the product yields and the qualities of the liquid products. The result showed that the optimal conditions for liquid yield (56.8%) were a pyrolysis temperature of 550 degrees C, gas flow rate of 3.4 L/min, static bed height of 10 cm and particle size of 1.0-2.0mm. The presence of the catalyst increased the yields of non-condensable gas, water and coke, while decreased the liquid and char yields. The elemental analysis showed that more than 25% decrease in oxygen content of the collected liquid in the second condenser with HZSM-5 was observed compared with that without catalyst. The H/C, O/C molar ratios and the higher heating value of the oil fraction in the collected liquid with the catalyst were 1.511, 0.149 and 34.6 MJ/kg, respectively. It was indicated that the collected liquid in the second condenser had high qualities and might be used as transport oil.

Heat-Related Mortality in Japan after the 2011 Fukushima Disaster: An Analysis of Potential Influence of Reduced Electricity Consumption

PubMed Central

Kim, Yoonhee; Gasparrini, Antonio; Honda, Yasushi; Ng, Chris Fook Sheng; Armstrong, Ben

2017-01-01

Background: In March 2011, the Great East Japan Earthquake devastated several power stations and caused severe electricity shortages. This accident was followed by the implementation of policies to reduce summer electricity consumption in the affected areas, for example, by limiting air-conditioning (AC) use. This provided a natural experimental scenario to investigate if these policies were associated with an increase in heat-related mortality. Objectives: We examined whether the reduced electricity consumption in warm season modified heat-related mortality from 2008 to 2012. Methods: We conducted prefecture-specific interrupted time-series (ITS) analyses to compare temperature–mortality associations before and after the earthquake, and used meta-analysis to generate combined effect estimates for the most affected and less affected areas (prefectures with >10% or ≤10% reductions in electricity consumption, respectively). We then examined whether the temperature–mortality association in Tokyo, one of the most affected areas, was modified by the percent reduction in electricity consumption relative to expected consumption for comparable days before the earthquake. Results: Contrary to expectations, we estimated a 5–9% reduction in all-cause heat-related mortality after the earthquake in the 15 prefectures with the greatest reduction in electricity consumption, and little change in the other prefectures. However, the percent reduction in observed vs. expected daily electricity consumption after the earthquake did not significantly modify daily heat-related mortality in Tokyo. Conclusions: In the prefectures with the greatest reductions in electricity consumption, heat-related mortality decreased rather than increased following the Great East Japan Earthquake. Additional research is needed to determine whether this finding holds for other populations and regions, and to clarify its implications for policies to reduce the consequences of climate change on health. https://doi.org/10.1289/EHP493 PMID:28686555

Heat-Related Mortality in Japan after the 2011 Fukushima Disaster: An Analysis of Potential Influence of Reduced Electricity Consumption.

PubMed

Kim, Yoonhee; Gasparrini, Antonio; Hashizume, Masahiro; Honda, Yasushi; Ng, Chris Fook Sheng; Armstrong, Ben

2017-07-06

In March 2011, the Great East Japan Earthquake devastated several power stations and caused severe electricity shortages. This accident was followed by the implementation of policies to reduce summer electricity consumption in the affected areas, for example, by limiting air-conditioning (AC) use. This provided a natural experimental scenario to investigate if these policies were associated with an increase in heat-related mortality. We examined whether the reduced electricity consumption in warm season modified heat-related mortality from 2008 to 2012. We conducted prefecture-specific interrupted time-series (ITS) analyses to compare temperature-mortality associations before and after the earthquake, and used meta-analysis to generate combined effect estimates for the most affected and less affected areas (prefectures with >10% or ≤10% reductions in electricity consumption, respectively). We then examined whether the temperature-mortality association in Tokyo, one of the most affected areas, was modified by the percent reduction in electricity consumption relative to expected consumption for comparable days before the earthquake. Contrary to expectations, we estimated a 5-9% reduction in all-cause heat-related mortality after the earthquake in the 15 prefectures with the greatest reduction in electricity consumption, and little change in the other prefectures. However, the percent reduction in observed vs. expected daily electricity consumption after the earthquake did not significantly modify daily heat-related mortality in Tokyo. In the prefectures with the greatest reductions in electricity consumption, heat-related mortality decreased rather than increased following the Great East Japan Earthquake. Additional research is needed to determine whether this finding holds for other populations and regions, and to clarify its implications for policies to reduce the consequences of climate change on health. https://doi.org/10.1289/EHP493.

Characterizing precipitate evolution of an Al–Zn–Mg–Cu-based commercial alloy during artificial aging and non-isothermal heat treatments by in situ electrical resistivity monitoring

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

Jiang, Fulin; Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7; Zurob, Hatem S., E-mail: zurobh@mcmaster.ca

In situ electrical resistivity monitoring technique was employed to continuously evaluate the precipitate evolution of an Al–Zn–Mg–Cu-based commercial alloy during typical artificial aging treatments. The effects of artificial aging on the precipitates stability during non-isothermal heat treatments were also explored. Conventional hardness test, transmission electron microscopy and differential scanning calorimetry were also adopted to verify the electrical resistivity results. The results indicated that both the precipitation process and its timely rate could be followed by the monitored electrical resistivity during artificial aging treatments. The electrical resistivity results gave overall information on continuous precipitation and dissolution processes, especially under high heatingmore » rates. Samples artificial aging heat treated at 120 °C for 24 h followed by aging at 150 °C for 24 h presented more stable state and coarser precipitates than the samples only artificial aging heat treated at 120 °C for 24 h or triple artificial aging heat treated at 120 °C/24 h + 195 °C/15 min + 120 °/24 h. While the incoherent η precipitates in the samples artificial aging heat treated at 120 °C for 24 h followed by aging at 150 °C for 24 h were more easiness to coarsening and dissolve during non-isothermal heat treatments as well. - Highlights: • In situ electrical resistivity monitoring technique was employed on an Al-Zn-Mg-Cu alloy. • The precipitate evolution during typical artificial aging treatments was studied. • The precipitate stability during non-isothermal heat treatments was explored. • The electrical resistivity wonderfully monitored continuous precipitation and dissolution. • The alloy submitted to a T7 treatment presents a more stable state during heating due to incoherent η precipitates.« less

Microwave absorption in powders of small conducting particles for heating applications.

PubMed

Porch, Adrian; Slocombe, Daniel; Edwards, Peter P

2013-02-28

In microwave chemistry there is a common misconception that small, highly conducting particles heat profusely when placed in a large microwave electric field. However, this is not the case; with the simple physical explanation that the electric field (which drives the heating) within a highly conducting particle is highly screened. Instead, it is the magnetic absorption associated with induction that accounts for the large experimental heating rates observed for small metal particles. We present simple principles for the effective heating of particles in microwave fields from calculations of electric and magnetic dipole absorptions for a range of practical values of particle size and conductivity. For highly conducting particles, magnetic absorption dominates electric absorption over a wide range of particle radii, with an optimum absorption set by the ratio of mean particle radius a to the skin depth δ (specifically, by the condition a = 2.41δ). This means that for particles of any conductivity, optimized magnetic absorption (and hence microwave heating by magnetic induction) can be achieved by simple selection of the mean particle size. For weakly conducting samples, electric dipole absorption dominates, and is maximized when the conductivity is approximately σ ≈ 3ωε(0) ≈ 0.4 S m(-1), independent of particle radius. Therefore, although electric dipole heating can be as effective as magnetic dipole heating for a powder sample of the same volume, it is harder to obtain optimized conditions at a fixed frequency of microwave field. The absorption of sub-micron particles is ineffective in both magnetic and electric fields. However, if the particles are magnetic, with a lossy part to their complex permeability, then magnetic dipole losses are dramatically enhanced compared to their values for non-magnetic particles. An interesting application of this is the use of very small magnetic particles for the selective microwave heating of biological samples.

REEXAMINATION OF INDUCTION HEATING OF PRIMITIVE BODIES IN PROTOPLANETARY DISKS

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

Menzel, Raymond L.; Roberge, Wayne G., E-mail: menzer@rpi.edu, E-mail: roberw@rpi.edu

2013-10-20

We reexamine the unipolar induction mechanism for heating asteroids originally proposed in a classic series of papers by Sonett and collaborators. As originally conceived, induction heating is caused by the 'motional electric field' that appears in the frame of an asteroid immersed in a fully ionized, magnetized solar wind and drives currents through its interior. However, we point out that classical induction heating contains a subtle conceptual error, in consequence of which the electric field inside the asteroid was calculated incorrectly. The problem is that the motional electric field used by Sonett et al. is the electric field in themore » freely streaming plasma far from the asteroid; in fact, the motional field vanishes at the asteroid surface for realistic assumptions about the plasma density. In this paper we revisit and improve the induction heating scenario by (1) correcting the conceptual error by self-consistently calculating the electric field in and around the boundary layer at the asteroid-plasma interface; (2) considering weakly ionized plasmas consistent with current ideas about protoplanetary disks; and (3) considering more realistic scenarios that do not require a fully ionized, powerful T Tauri wind in the disk midplane. We present exemplary solutions for two highly idealized flows that show that the interior electric field can either vanish or be comparable to the fields predicted by classical induction depending on the flow geometry. We term the heating driven by these flows 'electrodynamic heating', calculate its upper limits, and compare them to heating produced by short-lived radionuclides.« less

Metal phthalocyanine intermediates for the preparation of polymers

NASA Technical Reports Server (NTRS)

Achar, B. N.; Fohlen, G. M.; Parker, J. A.

1985-01-01

Metal 4, 4', 4"",-tetracarboxylic phthalocyanines (MPTC) are prepared by reaction of trimellitic anhydride, a salt or hydroxide of the desired metal (or the metal in powdered form), urea and a catalyst. A purer form of MPTC is prepared than heretofore. These tetracarboxylic acids are then polymerized by heat to sheet polymers which have superior heat and oxidation resistance. The metal is preferably a divalent metal having an atomic radius close to 1.35A.

Inhibition and Cathalysis as a Method to Improve the Mechanical Properties of a Fiberglass-Reinforced Plastic

NASA Astrophysics Data System (ADS)

Protsenko, A. E.; Telesh, V. V.

2015-11-01

The possibility of increasing the static flexural strength of polymer composite materials and reducing their anisotropy by vacuum autoclave curing, during which gelation across the whole thickness of prepregs is carried out in a narrow time range, is shown. This is achieved by introducing a preset concentration of catalysts into the less heated layers or inhibitors in the more heated ones of the prepreg.

Hierarchical Mesoporous NiO/MnO2@PANI Core-Shell Microspheres, Highly Efficient and Stable Bifunctional Electrocatalysts for Oxygen Evolution and Reduction Reactions.

PubMed

He, Junkai; Wang, Mingchao; Wang, Wenbo; Miao, Ran; Zhong, Wei; Chen, Sheng-Yu; Poges, Shannon; Jafari, Tahereh; Song, Wenqiao; Liu, Jiachen; Suib, Steven L

2017-12-13

We report on the new facile synthesis of mesoporous NiO/MnO 2 in one step by modifying inverse micelle templated UCT (University of Connecticut) methods. The catalyst shows excellent electrocatalytic activity and stability for both the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) in alkaline media after further coating with polyaniline (PANI). For electrochemical performance, the optimized catalyst exhibits a potential gap, ΔE, of 0.75 V to achieve a current of 10 mA cm -2 for the OER and -3 mA cm -2 for the ORR in 0.1 M KOH solution. Extensive characterization methods were applied to investigate the structure-property of the catalyst for correlations with activity (e.g., XRD, BET, SEM, HRTEM, FIB-TEM, XPS, TGA, and Raman). The high electrocatalytic activity of the catalyst closely relates to the good electrical conductivity of PANI, accessible mesoporous structure, high surface area, as well as the synergistic effect of the specific core-shell structure. This work opens a new avenue for the rational design of core-shell structure catalysts for energy conversion and storage applications.

Systematic study on the discharge product of Pt-based lithium oxygen batteries

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

Wu, Feng; Xing, Yi; Bi, Xuanxuan

Lithium oxygen batteries have attracted much attention due to the high theoretical energy density. However, they suffer a large overpotential during oxygen evolution process and thus catalysts play a vital role in the reaction. Here, we systematically explored the influence of Pt-based nanoparticle catalysts on the discharge product Li 2O 2. Because of the superior electrical conductivity and the strong binding with oxygen, Pt-based nanoparticles serve as active sites which are favorable for the growth of toroidal Li 2O 2. We also found that the content and composition of Pt-based nanoparticle catalysts exert a significant influence on the electrochemical performancemore » of lithium oxygen batteries. The discharge products are composed of crystalline Li 2O 2 and oxygen-rich LiO 2 characterized by high-energy X-ray diffraction and Raman. Atomic force microscopy further provides detailed information of the particle size and surface roughness. The loading of Pt catalysts determines the phase and size of Li 2O 2 on the discharged electrode surface. This study will be beneficial for the optimization of Pt-based catalysts used in non-aqueous lithium oxygen batteries.« less

Systematic study on the discharge product of Pt-based lithium oxygen batteries

NASA Astrophysics Data System (ADS)

Wu, Feng; Xing, Yi; Bi, Xuanxuan; Yuan, Yifei; Wang, Hsien-Hau; Shahbazian-Yassar, Reza; Li, Li; Chen, Renjie; Lu, Jun; Amine, Khalil

2016-11-01

Lithium oxygen batteries have attracted much attention due to the high theoretical energy density. However, they suffer a large overpotential during oxygen evolution process and thus catalysts play a vital role in the reaction. Here, we systematically explored the influence of Pt-based nanoparticle catalysts on the discharge product Li2O2. Because of the superior electrical conductivity and the strong binding with oxygen, Pt-based nanoparticles serve as active sites which are favorable for the growth of toroidal Li2O2. We also found that the content and composition of Pt-based nanoparticle catalysts exert a significant influence on the electrochemical performance of lithium oxygen batteries. The discharge products are composed of crystalline Li2O2 and oxygen-rich LiO2 characterized by high-energy X-ray diffraction and Raman. Atomic force microscopy further provides detailed information of the particle size and surface roughness. The loading of Pt catalysts determines the phase and size of Li2O2 on the discharged electrode surface. This study will be beneficial for the optimization of Pt-based catalysts used in non-aqueous lithium oxygen batteries.

Novel strategy to mitigate cathode catalyst degradation during air/air startup cycling via the atmospheric resistive switching mechanism of a hydrogen anode with a platinum catalyst supported on tantalum-doped titanium dioxide

NASA Astrophysics Data System (ADS)

Shintani, Haruhiko; Kojima, Yuya; Kakinuma, Katsuyoshi; Watanabe, Masahiro; Uchida, Makoto

2015-10-01

We propose a new strategy for alleviating the reverse current phenomenon using a unique ;atmospheric resistive switching mechanism; (ARSM) of a metal oxide semiconductor support, such that the electrical resistivity changes depending on the gas atmosphere. The membrane-electrode assembly (MEA) using Ta-doped TiO2-supported platinum (Pt/Ta-TiO2) as the anode catalyst showed approximately one order of magnitude greater resistance in air than in hydrogen. The overpotential of the hydrogen oxidation reaction was negligible up to at least 1.5 A cm-2. The losses of electrochemically active surface area and carbon corrosion of the cathode catalyst during air/air startup cycling were significantly suppressed by the use of the Pt/Ta-TiO2 anode. The decrease in the degradation is attributed to a reduction of the reverse current due to a low oxygen reduction reaction rate at the anode, which showed high resistivity in air. These results demonstrate the effectiveness of the ARSM in mitigating cathode catalyst degradation during air/air startup cycling.