Photoactive lead oxide thin films by spray pyrolysis

NASA Astrophysics Data System (ADS)

Bhagat, Dharini; Waldiya, Manmohansingh; Mukhopadhyay, Indrajit

2018-05-01

We report the synthesis of photoactive lead monoxide thin films on fluorine doped tin oxide substrate by cost effective spray pyrolysis technique using aqueous solution of lead acetate trihydrate. Influence of substrate temperature on the structural and optical properties of thin films was studied. Polymorph of lead monoxide, litharge (α-PbO), was obtained when the substrate temperature was kept constant at 360 °C. XRD analysis revealed that the deposits were tetragonal structured with preferred orientation along 002 plane. Band gap value was found to be 1.93ev from diffuse reflectance spectra.

Properties of transparent conducting tin monoxide(SnO) thin films prepared by chemical spray pyrolysis method

NASA Astrophysics Data System (ADS)

Eqbal, Ebitha; Anila, E. I.

2018-01-01

Transparent conducting Stannous Oxide (SnO) thin films were obtained by chemical spray pyrolysis method on glass substrates for 0.1 M and 0.25 M concentration of precursor solutions. Their structural, morphological, optical and electrical properties were investigated. X-ray diffraction (XRD) study shows polycrystalline nature of the films with orthorhombic crystal structure. The morphological analysis was carried out by Scanning electron microscopy (SEM) and elemental analysis was done by Energy dispersive X-ray spectroscopy (EDX). The band gap of 0.1 M and 0.25 M thin film samples were found to be 3.58eV with 82% transmission and 3 eV with 30% transmission respectively. The film thickness, refractive index (n) and extinction coefficient (k) of the films were obtained by ellipsometric technique. Hall effect measurements reveal p-type conduction with mobility 7.8 cm2V-1s-1 and 15 cm2V-1s-1 and conductivity of 8.5 S/cm and 17.1 S/cm respectively for the 0.1 M and 0.25 M samples. Photoluminescence (PL) spectrum of the samples show a broad emission which covers near band edge (NBE) as well as deep level emission (DLE) in the region 380 nm-620 nm.

Compositional dependence of optical and electrical properties of indium doped zinc oxide (IZO) thin films deposited by chemical spray pyrolysis

NASA Astrophysics Data System (ADS)

Dintle, Lawrence K.; Luhanga, Pearson V. C.; Moditswe, Charles; Muiva, Cosmas M.

2018-05-01

The structural and optoelectronic properties of undoped and indium doped zinc oxide (IZO) thin films grown on glass substrates through a simple reproducible custom-made pneumatic chemical spray pyrolysis technique are presented. X-ray diffraction (XRD) results showed a polycrystalline structure of hexagonal wurtzite phase growing preferentially along the (002) plane for the undoped sample. Increase in dopant content modified the orientation leading to more pronounced (100) and (101) reflections. Optical transmission spectra showed high transmittance of 80-90% in the visible range for all thin films. The optical band gap energy (Eg) was evaluated on the basis of the derivative of transmittance (dT/dλ) versus wavelength (λ) model and Tauc's extrapolation method in the region where the absorption coefficient, α ≥ 104 cm-1. The observed values of Eg were found to decrease generally with increasing In dopant concentration. From the figure of merit calculations a sample with 4 at.% In dopant concentration showed better optoelectronic properties.

Photoluminescence in Spray Pyrolysis Deposited β-In2S3 Thin Films

NASA Astrophysics Data System (ADS)

Jayakrishnan, R.

2018-04-01

Spray pyrolysis deposited In2S3 thin films exhibit two prominent photoluminescent emissions. One of the emissions is green in color and centered at around ˜ 540 nm and the other is centered at around ˜ 690 nm and is red in color. The intensity of the green emission decreases when the films are subjected to annealing in air or vacuum. The intensity of red emission increases when films are air annealed and decreases when vacuum annealed. Vacuum annealing leads to an increase in work function whereas air annealing leads to a decrease in work function for this thin film system relative to the as deposited films indicating changes in space charge regions. Surface photovoltage analysis using a Kelvin probe leads to the conclusion that inversion of band bending occurs as a result of annealing. Correlating surface contact potential measurements using a Kelvin probe, x-ray photoelectron spectroscopy and photoluminescence, we conclude that the surface passivation plays a critical role in controlling the photoluminescence from the spray pyrolysis deposited for In2S3 thin films.

Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

NASA Astrophysics Data System (ADS)

Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

2016-03-01

Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

Sb2S3 grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell

PubMed Central

Katerski, Atanas; Oja Acik, Ilona; Mere, Arvo; Mikli, Valdek; Krunks, Malle

2016-01-01

Chemical spray pyrolysis (CSP) is a fast wet-chemical deposition method in which an aerosol is guided by carrier gas onto a hot substrate where the decomposition of the precursor chemicals occurs. The aerosol is produced using an ultrasonic oscillator in a bath of precursor solution and guided by compressed air. The use of the ultrasonic CSP resulted in the growth of homogeneous and well-adhered layers that consist of submicron crystals of single-phase Sb2S3 with a bandgap of 1.6 eV if an abundance of sulfur source is present in the precursor solution (SbCl3/SC(NH2)2 = 1:6) sprayed onto the substrate at 250 °C in air. Solar cells with glass-ITO-TiO2-Sb2S3-P3HT-Au structure and an active area of 1 cm2 had an open circuit voltage of 630 mV, short circuit current density of 5 mA/cm2, a fill factor of 42% and a conversion efficiency of 1.3%. Conversion efficiencies up to 1.9% were obtained from solar cells with smaller areas. PMID:28144515

Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells.

PubMed

Ji, Ran; Zheng, Ding; Zhou, Chang; Cheng, Jiang; Yu, Junsheng; Li, Lu

2017-07-18

Tungsten oxide (WO₃) is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL) for organic solar cells (OSCs). The properties of the WO₃ transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO₃ ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO₃, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO₃ ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO₃, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication.

Uniform nanoparticles by flame-assisted spray pyrolysis (FASP) of low cost precursors

PubMed Central

Rudin, Thomas; Wegner, Karsten

2013-01-01

A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and solvents (e.g., ethanol) for synthesis of nanoparticles (10–20 nm) with uniform characteristics. In this reactor design, a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel gases (acetylene or methane) at a defined height above the atomizing nozzle. The gaseous fuel feed can be varied to control the combustion enthalpy content of the flame and onset of particle formation. This way, the enthalpy density of the flame is decoupled from the precursor solution composition. Low enthalpy content precursor solutions are prone to synthesis of non-uniform particles (e.g., bimodal particle size distribution) by standard flame spray pyrolysis (FSP) processes. For example, metal nitrates in ethanol typically produce nanosized particles by gas-to-particle conversion along with larger particles by droplet-to-particle conversion. The present FASP design facilitates the use of such low enthalpy precursor solutions for synthesis of homogeneous nanopowders by increasing the combustion enthalpy density of the flame with low-cost, gaseous fuels. The effect of flame enthalpy density on product properties in the FASP configuration is explored by the example of Bi2O3 nanoparticles produced from bismuth nitrate in ethanol. Product powders were characterized by nitrogen adsorption, X-ray diffraction, X-ray disk centrifuge, and transmission electron microscopy. Homogeneous Bi2O3 nanopowders were produced both by increasing the gaseous fuel content and, most notably, by cutting the air entrainment prior to ignition of the spray. PMID:23408113

Growth of ultra-thin TiO 2 films by spray pyrolysis on different substrates

NASA Astrophysics Data System (ADS)

Oja Acik, I.; Junolainen, A.; Mikli, V.; Danilson, M.; Krunks, M.

2009-12-01

In the present study TiO 2 films were deposited by spray pyrolysis method onto ITO covered glass and Si (1 0 0) substrates. The spray solution containing titanium(IV) isopropoxide, acetylacetone and ethanol was sprayed at a substrate temperature of 450 °C employing 1-125 spray pulses (1 s spray and 30 s pause). According to AFM, continuous coverage of ITO and Si substrates with TiO 2 layer is formed by 5-10 and below 5 spray pulses, respectively. XPS studies revealed that TiO 2 film growth on Si substrate using up to 4 spray pulses follows 2D or layer-by-layer-growth. Above 4 spray pulses, 3D or island growth becomes dominant irrespective of the substrate. Only 50 spray pulses result in TiO 2 layer with the thickness more than XPS measurement escape depth as any signal from the substrate could not be detected. TiO 2 grain size remains 30 nm on ITO and increases from 10-20 nm to 50-100 nm on Si substrate with the number of spray pulses from 1 to 125.

Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells

PubMed Central

Ji, Ran; Zheng, Ding; Zhou, Chang; Cheng, Jiang; Yu, Junsheng; Li, Lu

2017-01-01

Tungsten oxide (WO3) is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL) for organic solar cells (OSCs). The properties of the WO3 transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO3 ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO3, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO3 ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO3, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication. PMID:28773177

Characteristics of Fe powders prepared by spray pyrolysis from a spray solution with ethylene glycol as the source material of heat pellet

NASA Astrophysics Data System (ADS)

Koo, H. Y.; Kim, J. H.; Hong, S. K.; Ko, Y. N.; Jang, H. C.; Jung, D. S.; Han, J. M.; Hong, Y. J.; Kang, Y. C.; Kang, S. H.; Cho, S. B.

2012-06-01

Fe powders as the heat pellet material for thermal batteries are prepared from iron oxide powders obtained by spray pyrolysis from a spray solution of iron nitrate with ethylene glycol. The iron oxide powders with hollow and thin wall structure produce Fe powders with elongated structure and fine primary particle size at a low reducing temperature of 615 °C. The mean size of the primary Fe powders with elongated structure decreases with increasing concentration of ethylene glycol dissolved into the spray solution. The heat pellets prepared from the fine-size Fe powders with elongated structure have good ignition sensitivities below 1 watt. The heat pellets formed from the Fe powders obtained from the spray solution with 0.5 M EG have an extremely high burn rate of 26 cms-1.

Flame spray pyrolysis for sensing at the nanoscale.

PubMed

Kemmler, J A; Pokhrel, S; Mädler, L; Weimar, U; Barsan, N

2013-11-08

Progress in developing novel gas sensors based on semiconducting metal oxides (SMOX) has been hindered by the cumbersome fabrication technologies currently employed. They involve time intensive synthesis procedures for gaining sensitive materials and preparation of the inks employed for realizing sensing layers. In this paper we review the opportunities offered by the relatively young method of flame spray pyrolysis, with which it is possible not only to synthesize a broad selection of SMOX in pure or doped form, but also to simultaneously deposit thick and highly porous gas sensitive films on a variety of substrates. In less than ten years the properties of nine base materials have been evaluated for all most relevant target gases and the obtained results are promising for future development.

Flame spray pyrolysis for sensing at the nanoscale

NASA Astrophysics Data System (ADS)

Kemmler, J. A.; Pokhrel, S.; Mädler, L.; Weimar, U.; Barsan, N.

2013-11-01

Progress in developing novel gas sensors based on semiconducting metal oxides (SMOX) has been hindered by the cumbersome fabrication technologies currently employed. They involve time intensive synthesis procedures for gaining sensitive materials and preparation of the inks employed for realizing sensing layers. In this paper we review the opportunities offered by the relatively young method of flame spray pyrolysis, with which it is possible not only to synthesize a broad selection of SMOX in pure or doped form, but also to simultaneously deposit thick and highly porous gas sensitive films on a variety of substrates. In less than ten years the properties of nine base materials have been evaluated for all most relevant target gases and the obtained results are promising for future development.

ZnO layers prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

Messaoudi, C.; Abd-Lefdil, S.; Sayah, D.; Cadene, M.

1998-02-01

Highly transparent undoped and indium doped ZnO thin films have been grown on glass substrates by using the spray pyrolysis process. Conditions of preparation have been optimized to get good quality and reproducible films with required properties. Polycrystalline films with an hexagonal Wurtzite-type structure were easily obtained under the optimum spraying conditions. Both of samples have shown high transmission coefficient in the visible and infrared wavelength range with sharp absorption edge around 380 nm which closely corresponds to the intrinsic band-gap of ZnO (3.2 eV). Orientation and crystallites size were remarkably modified by deposition temperature and indium doping. Des couches minces de ZnO, hautement transparentes, non dopées et dopées à l'indium ont été élaborées sur un substrat en verre par le procédé de pulvérisation chimique réactive spray. Les conditions de préparation ont été optimisées pour l'obtention de couches reproductibles, de bonne qualité et ayant les propriétés requises. Des films polycristallins, présentant une structure hexagonale de type Wurtzite, ont été aisément obtenus dans les conditions optimales de pulvérisation. Tous les échantillons ont présenté un coefficient de transmission élevé dans le domaine du visible et du proche infrarouge, avec une absorption brutale au voisinage de 380 nm, correspondant au gap optique du ZnO (3,2 eV). L'orientation et la taille des cristallites ont été remarquablement modifiées par la température du dépôt et par le dopage à l'indium.

Selectivity Enhancement by Using Double-Layer MOX-Based Gas Sensors Prepared by Flame Spray Pyrolysis (FSP).

PubMed

Rebholz, Julia; Grossmann, Katharina; Pham, David; Pokhrel, Suman; Mädler, Lutz; Weimar, Udo; Barsan, Nicolae

2016-09-06

Here we present a novel concept for the selective recognition of different target gases with a multilayer semiconducting metal oxide (SMOX)-based sensor device. Direct current (DC) electrical resistance measurements were performed during exposure to CO and ethanol as single gases and mixtures of highly porous metal oxide double- and single-layer sensors obtained by flame spray pyrolysis. The results show that the calculated resistance ratios of the single- and double-layer sensors are a good indicator for the presence of specific gases in the atmosphere, and can constitute some building blocks for the development of chemical logic devices. Due to the inherent lack of selectivity of SMOX-based gas sensors, such devices could be especially relevant for domestic applications.

Selectivity Enhancement by Using Double-Layer MOX-Based Gas Sensors Prepared by Flame Spray Pyrolysis (FSP)

PubMed Central

Rebholz, Julia; Grossmann, Katharina; Pham, David; Pokhrel, Suman; Mädler, Lutz; Weimar, Udo; Barsan, Nicolae

2016-01-01

Here we present a novel concept for the selective recognition of different target gases with a multilayer semiconducting metal oxide (SMOX)-based sensor device. Direct current (DC) electrical resistance measurements were performed during exposure to CO and ethanol as single gases and mixtures of highly porous metal oxide double- and single-layer sensors obtained by flame spray pyrolysis. The results show that the calculated resistance ratios of the single- and double-layer sensors are a good indicator for the presence of specific gases in the atmosphere, and can constitute some building blocks for the development of chemical logic devices. Due to the inherent lack of selectivity of SMOX-based gas sensors, such devices could be especially relevant for domestic applications. PMID:27608028

Electrical properties of transparent conductive ATO coatings obtained by spray pyrolysis

NASA Astrophysics Data System (ADS)

Zinchenko, T. O.; Kondrashin, V. I.; Pecherskaya, E. A.; Kozlyakov, A. S.; Nikolaev, K. O.; Shepeleva, J. V.

2017-08-01

Transparent conductive coatings based on thin films of metal oxides have been widely spread in various optoelectronic devices and appliances. It is necessary to determine the influence of preparation conditions on coatings properties for their use in the solution of certain tasks. Thin films of tin dioxide were obtained by the method of spray pyrolysis on glass substrates. Surface resistance and resistivity, concentration and mobility of charge carriers, the conductivity were measured, and the dependences showing the effect of preparation conditions on electrical properties of optically transparent coatings.

Chemical pyrolysis of E-waste plastics: Char characterization.

PubMed

Shen, Yafei; Chen, Xingming; Ge, Xinlei; Chen, Mindong

2018-05-15

This work studied the disposal of the non-metallic fraction from waste printed circuit board (NMF-WPCB) via the chemical pretreatments followed by pyrolysis. As a main heavy metal, the metallic Cu could be significantly removed by 92.4% using the HCl leaching process. Subsequently, the organic-Br in the brominated flame retardants (BFRs) plastics could be converted into HBr by pyrolysis. The alkali pretreatment was benefit for the Br fixation in the solid char. The Br fixation efficiency could reach up to 53.6% by the NaOH pretreatment followed by the pyrolysis process. The formed HBr could react with NaOH/KOH to generate the stabilized NaBr/KBr. Therefore, the integrated chemical pretreatment could be used for the eco-friendly disposal of the NMF-WPCB via pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fates of Chemical Elements in Biomass during Its Pyrolysis.

PubMed

Liu, Wu-Jun; Li, Wen-Wei; Jiang, Hong; Yu, Han-Qing

2017-05-10

Biomass is increasingly perceived as a renewable resource rather than as an organic solid waste today, as it can be converted to various chemicals, biofuels, and solid biochar using modern processes. In the past few years, pyrolysis has attracted growing interest as a promising versatile platform to convert biomass into valuable resources. However, an efficient and selective conversion process is still difficult to be realized due to the complex nature of biomass, which usually makes the products complicated. Furthermore, various contaminants and inorganic elements (e.g., heavy metals, nitrogen, phosphorus, sulfur, and chlorine) embodied in biomass may be transferred into pyrolysis products or released into the environment, arousing environmental pollution concerns. Understanding their behaviors in biomass pyrolysis is essential to optimizing the pyrolysis process for efficient resource recovery and less environmental pollution. However, there is no comprehensive review so far about the fates of chemical elements in biomass during its pyrolysis. Here, we provide a critical review about the fates of main chemical elements (C, H, O, N, P, Cl, S, and metals) in biomass during its pyrolysis. We overview the research advances about the emission, transformation, and distribution of elements in biomass pyrolysis, discuss the present challenges for resource-oriented conversion and pollution abatement, highlight the importance and significance of understanding the fate of elements during pyrolysis, and outlook the future development directions for process control. The review provides useful information for developing sustainable biomass pyrolysis processes with an improved efficiency and selectivity as well as minimized environmental impacts, and encourages more research efforts from the scientific communities of chemistry, the environment, and energy.

Properties of NiO thin films deposited by intermittent spray pyrolysis process

NASA Astrophysics Data System (ADS)

Reguig, B. A.; Khelil, A.; Cattin, L.; Morsli, M.; Bernède, J. C.

2007-02-01

NiO thin films have been grown on glass substrates by intermittent spray pyrolysis deposition of NiCl 2·6H 2O diluted in distilled water, using a simple "perfume atomizer". The effect of the solution molarity on their properties was studied and compared to those of NiO thin films deposited with a classical spray system. It is shown that NiO thin films crystallized in the NiO structure are achieved after deposition. Whatever the precursor molarity, the grain size is around 25-30 nm. The crystallites are preferentially oriented along the (1 1 1) direction. All the films are p-type. However, the thickness and the conductivity of the NiO films depend on the precursor contraction. By comparison with the properties of films deposited by classical spray technique, it is shown that the critical precursor concentration, which induces strong thin films properties perturbations, is higher when a perfume atomizer is used. This broader stability domain can be attributed to better chlorides decomposition during the rest time used in the perfume atomizer technique.

Characterization and Electrochromic Properties of Vanadium Oxide Thin Films Prepared via Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

2013-08-01

Vanadium oxide thin films were grown on glass substrates using spray pyrolysis technique. The effects of substrate temperature, vanadium concentration in the initial solution and the solution spray rate on the nanostructural and the electrochromic properties of deposited films are investigated. Characterization and the electrochromic measurements were carried out using X-ray diffraction, scanning electron microscopy and cyclic voltammogram. XRD patterns showed that the prepared films have polycrystalline structure and are mostly mixed phases of orthorhombic α-V2O5 along with minor β-V2O5 and V4O9 tetragonal structures. The preferred orientation of the deposited films was found to be along [101] plane. The cyclic voltammogram results obtained for different samples showed that only the films with 0.2 M solution concentration, 5 ml/min solution spray rate and 450°C substrate temperature exhibit two-step electrochromic properties. The results show a correlation between cycle voltammogram, morphology and resistance of the films.

Flash Vacuum Pyrolysis: Techniques and Reactions.

PubMed

Wentrup, Curt

2017-11-20

Flash vacuum pyrolysis (FVP) had its beginnings in the 1940s and 1950s, mainly through mass spectrometric detection of pyrolytically formed free radicals. In the 1960s many organic chemists started performing FVP experiments with the purpose of isolating new and interesting compounds and understanding pyrolysis processes. Meanwhile, many different types of apparatus and techniques have been developed, and it is the purpose of this review to present the most important methods as well as a survey of typical reactions and observations that can be achieved with the various techniques. This includes preparative FVP, chemical trapping reactions, matrix isolation, and low temperature spectroscopy of reactive intermediates and unstable molecules, the use of online mass, photoelectron, microwave, and millimeterwave spectroscopies, gas-phase laser pyrolysis, pulsed pyrolysis with supersonic jet expansion, very low pressure pyrolysis for kinetic investigations, solution-spray and falling-solid FVP for involatile compounds, and pyrolysis over solid supports and reagents. Moreover, the combination of FVP with matrix isolation and photochemistry is a powerful tool for investigations of reaction mechanism. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vertically Aligned Carbon Nanotubes at Different Temperatures by Spray Pyrolysis Techniques

NASA Astrophysics Data System (ADS)

Afre, Rakesh A.; Soga, T.; Jimbo, T.; Kumar, Mukul; Ando, Y.; Sharon, M.

Vertically aligned arrays of multi-walled carbon nanotubes (VACNTs) were grown by spray pyrolysis of turpentine oil and ferrocene mixture at temperatures higher than 700°C. Using this simple method, we report the successful growth of vertically aligned nanotubes of ~300μm length and diameter in the range of ?20-80nm on Si(100) substrate. The ferrocene acts as an in situ Fe catalyst precursor, forming the nano-sized metallic iron particles for formation of VACNTs on the Si substrate. The morphological characteristics of VACNTs are confirmed by SEM, TEM and Raman spectroscopy and growth mechanism is discussed in short.

Properties of mixed molybdenum oxide iridium oxide thin films synthesized by spray pyrolysis

NASA Astrophysics Data System (ADS)

Patil, P. S.; Kawar, R. K.; Sadale, S. B.; Inamdar, A. I.; Deshmukh, H. P.

2006-09-01

Molybdenum-doped iridium oxide thin films have been deposited onto corning glass- and fluorine-doped tin oxide coated corning glass substrates at 350 °C by using a pneumatic spray pyrolysis technique. An aqueous solution of 0.01 M ammonium molybdate was mixed with 0.01 M iridium trichloride solution in different volume proportions and the resultant solution was used as a precursor solution for spraying. The as-deposited samples were annealed at 600 °C in air medium for 1 h. The structural, electrical and optical properties of as-deposited and annealed Mo-doped iridium oxide were studied and values of room temperature electrical resistivity, and thermoelectric power were estimated. The as-deposited samples with 2% Mo doping exhibit more pronounced electrochromism than other samples, including pristine Ir oxide.

Superior Na-ion storage properties of high aspect ratio SnSe nanoplates prepared by a spray pyrolysis process

NASA Astrophysics Data System (ADS)

Park, Gi Dae; Lee, Jong-Heun; Kang, Yun Chan

2016-06-01

SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions containing 100, 400, and 800% of the stoichiometric SeO2 content needed to form SnSe, are 407, 558, and 211 mA h g-1, respectively, after 50 cycles at a constant current density of 0.3 A g-1 their capacity retentions calculated from the second cycle onwards are 77, 100, and 60%, respectively. The phase pure SnSe nanoplates with a high aspect ratio show good cycling and rate performances for Na-ion storage.SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions

Macro controlling of copper oxide deposition processes and spray mode by using home-made fully computerized spray pyrolysis system

NASA Astrophysics Data System (ADS)

Essa, Mohammed Sh.; Chiad, Bahaa T.; Shafeeq, Omer Sh.

2017-09-01

Thin Films of Copper Oxide (CuO) absorption layer have been deposited using home-made Fully Computerized Spray Pyrolysis Deposition system FCSPD on glass substrates, at the nozzle to substrate distance equal to 20,35 cm, and computerized spray mode (continues spray, macro-control spray). The substrate temperature has been kept at 450 °c with the optional user can enter temperature tolerance values ± 5 °C. Also that fixed molar concentration of 0.1 M, and 2D platform speed or deposition platform speed of 4mm/s. more than 1000 instruction program code, and specific design of graphical user interface GUI to fully control the deposition process and real-time monitoring and controlling the deposition temperature at every 200 ms. The changing in the temperature has been recorded during deposition processes, in addition to all deposition parameters. The films have been characterized to evaluate the thermal distribution over the X, Y movable hot plate, the structure and optical energy gap, thermal and temperature distribution exhibited a good and uniform distribution over 20 cm2 hot plate area, X-ray diffraction (XRD) measurement revealed that the films are polycrystalline in nature and can be assigned to monoclinic CuO structure. Optical band gap varies from 1.5-1.66 eV depending on deposition parameter.

SnS2 Thin Film Deposition by Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Jaber, Abdallah Yahia; Alamri, Saleh Noaiman; Aida, Mohammed Salah

2012-06-01

Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

PubMed

Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

2016-02-01

Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%.

Investigation on V2O5 Thin Films Prepared by Spray Pyrolysis Technique

NASA Astrophysics Data System (ADS)

Anasthasiya, A. Nancy Anna; Gowtham, K.; Shruthi, R.; Pandeeswari, R.; Jeyaprakash, B. G.

The spray pyrolysis technique was employed to deposit V2O5 thin films on a glass substrate. By varying the precursor solution volume from 10mL to 50mL in steps of 10mL, films of various thicknesses were prepared. Orthorhombic polycrystalline V2O5 films were inferred from the XRD pattern irrespective of precursor solution volume. The micro-Raman studies suggested that annealed V2O5 thin film has good crystallinity. The effect of precursor solution volume on morphological and optical properties were analysed and reported.

Y2O3:Eu phosphor particles prepared by spray pyrolysis from a solution containing citric acid and polyethylene glycol

NASA Astrophysics Data System (ADS)

Roh, H. S.; Kang, Y. C.; Park, H. D.; Park, S. B.

Y2O3:Eu phosphor particles were prepared by large-scale spray pyrolysis. The morphological control of Y2O3:Eu particles in spray pyrolysis was attempted by adding polymeric precursors to the spray solution. The effect of composition and amount of polymeric precursors on the morphology, crystallinity and photoluminescence characteristics of Y2O3:Eu particles was investigated. Particles prepared from a solution containing polyethylene glycol (PEG) with an average molecular weight of 200 had a hollow structure, while those prepared from solutions containing adequate amounts of citric acid (CA) and PEG had a spherical shape, filled morphology and clean surfaces after post-treatment at high temperature. Y2O3:Eu particles prepared from an aqueous solution with no polymeric precursors had a hollow structure and rough surfaces after post-treatment. The phosphor particles prepared from solutions with inadequate amounts of CA and/or PEG also had hollow and/or fragmented structures. The particles prepared from the solution containing 0.3 M CA and 0.3 M PEG had the highest photoluminescence emission intensity, which was 56% higher than that of the particles prepared from aqueous solution without polymeric precursors.

Finding the chemistry in biomass pyrolysis: Millisecond chemical kinetics and visualization

NASA Astrophysics Data System (ADS)

Krumm, Christoph

Biomass pyrolysis is a promising thermochemical method for producing fuels and chemicals from renewable sources. Development of a fundamental understanding of biomass pyrolysis chemistry is difficult due to the multi-scale and multi-phase nature of the process; biomass length scales span 11 orders of magnitude and pyrolysis phenomena include solid, liquid, and gas phase chemistry in addition to heat and mass transfer. These complexities have a significant effect on chemical product distributions and lead to variability between reactor technologies. A major challenge in the study of biomass pyrolysis is the development of kinetic models capable of describing hundreds of millisecond-scale reactions of biomass into lower molecular weight products. In this work, a novel technique for studying biomass pyrolysis provides the first- ever experimental determination of kinetics and rates of formation of the primary products from cellulose pyrolysis, providing insight into the millisecond-scale chemical reaction mechanisms. These findings highlight the importance of heat and mass transport limitations for cellulose pyrolysis chemistry and are used to identify the length scales at which transport limitations become relevant during pyrolysis. Through this technique, a transition is identified, known as the reactive melting point, between low and high temperature depolymerization. The transition between two mechanisms of cellulose decompositions unifies the mechanisms that govern low temperature char formation, intermediate pyrolysis conditions, and high temperature gas formation. The conditions under which biomass undergoes pyrolysis, including modes of heat transfer, have been shown to significantly affect the distribution of biorenewable chemical and fuel products. High-speed photography is used to observe the liftoff of initially crystalline cellulose particles when impinged on a heated surface, known as the Leidenfrost effect for room-temperature liquids. Order

Preparation of mesoporous alumina particles by spray pyrolysis and application to double bond migration of 2-butene.

PubMed

Song, Ki Chang; Kim, Joo Hyun; Kim, Jin Han; Jung, Kyeong Youl; Park, Young-Kwon; Jeon, Jong-Ki

2011-07-01

The objective of the present study is to investigate the catalytic performance of mesoporous alumina that were prepared via spray pyrolysis for double bond migration from 2-butene to 1-butene. The mesoporous alumina particles were prepared via spray pyrolysis by changing the types of organic surfactants and Al precursors. The texture and acidic properties of mesoporous alumina were analyzed through N2 adsorption, SEM, ammonia-temperature programmed desorption, and FT-IR of adsorbed pyridine. The morphologies and texture properties of the mesoporous alumina were found to have been strongly influenced by the combination of the Al precursor and the structure-directing agents. The mesoporous alumina samples had two kinds of acidic sites: a Lewis acid site and a H-bonded weak acid site. 1-Butene was produced selectively through double bond migration of 2-butene over all of the mesoporous alumina catalysts. The catalyst prepared by using a chloride compound as an aluminium precursor and CTAC as a structure-directing agent showed the highest activity in the double bond migration of 2-butene, which was attributed to its large surface area and an overall high amount of acid sites.

Value-added organonitrogen chemicals evolution from the pyrolysis of chitin and chitosan.

PubMed

Liu, Chao; Zhang, Huiyan; Xiao, Rui; Wu, Shubin

2017-01-20

Thermogravimetric characteristics of chitin and chitosan and their potentials to produce value-added organonitrogen chemicals were separately evaluated via TG/DSC-FTIR and Py-GC/MS. Results shown that chitin had the better thermal stability and higher activation energy than chitosan because of the abundant acetamido group. Furthermore, the dominated volatilization in active pyrolysis of chitin contributed to its endothermic property, whereas the charring in chitosan led to the exothermal. During fast pyrolysis, the acetamido group in chitin and chitosan was converted into acetic acid or acetamide. Typical products from chitosan pyrolysis were aza-heterocyclic chemicals, i.e. pyridines, pyrazines, and pyrroles, with the total selectivity of 50.50% at 600°C. Herein, selectivity of pyrazine compounds was up to 22.99%. These aza-heterocyclic chemicals came from the nucleophilic addition reaction of primary amine and carbonyl. However, main reaction during chitin pyrolysis was ring-opening degradation, which led to the formation of acetamido chemicals, especially acetamido acetaldehyde with the highest selectivity of 27.27% at 450°C. In summary, chitosan had the potential to produce aza-heterocyclic chemicals, and chitin to acetamido chemicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of solvent composition on oxide morphology during flame spray pyrolysis of metal nitrates.

PubMed

Strobel, Reto; Pratsinis, Sotiris E

2011-05-28

The effect of solvent composition on particle formation during flame spray pyrolysis of inexpensive metal-nitrates has been investigated for alumina, iron oxide, cobalt oxide, zinc oxide and magnesium oxide. The as-prepared materials were characterized by electron microscopy, nitrogen adsorption, X-ray diffraction (XRD) and disc centrifugation (XDC). The influence of solvent parameters such as boiling point, combustion enthalpy and chemical reactivity on formation of either homogeneous nanoparticles by evaporation/nucleation/coagulation (gas-to-particle conversion) or large particles through precipitation and conversion within the sprayed droplets (droplet-to-particle conversion) is discussed. For Al(2)O(3), Fe(2)O(3), Co(3)O(4) and partly also MgO, the presence of a carboxylic acid in the FSP solution resulted in homogeneous nanoparticles. This is attributed to formation of volatile metal carboxylates in solution as evidenced by attenuated total reflectance spectroscopy (ATR). For ZnO and MgO rather homogeneous nanoparticles were formed regardless of solvent composition. For ZnO this is attributed to its relatively low dissociation temperature compared to other oxides. While for MgO this is traced to the high decomposition temperature of Mg(NO(3))(2) together with Mg(OH)(2)↔MgO transformations. Cobalt oxide (Co(3)O(4)) nanoparticles made by FSP were not aggregated but rather loosely agglomerated as determined by the excellent agreement between XRD- and XDC-derived crystallite and particle sizes, respectively, pointing out the potential of FSP to make non-aggregated particles. This journal is © the Owner Societies 2011

Synthesis of Single Crystalline ZnO Nanoparticles by Salt-Assisted Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Panatarani, Camellia; Lenggoro, I. Wuled; Okuyama, Kikuo

2003-04-01

LiNO3 was used as a shield in the preparation of single crystalline ZnO particles by a spray pyrolysis process in order to prevent agglomeration and enhance the crystallinity of the ZnO. LiNO3 was added to a precursor solution of zinc acetate dihydrate prior to its atomization by means of an ultrasonic transducer. Agglomerate-free particles having a mean particle size of 26 nm were successfully obtained after washing the product. X-ray diffractometry, field-emission scanning electron micrograph and transmission electron micrograph data indicate that the size and morphology of ZnO were strongly influenced by the operating temperature used and the residence time of the particle in the reactor.

Comparative study on deposition of fluorine-doped tin dioxide thin films by conventional and ultrasonic spray pyrolysis methods for dye-sensitized solar modules

NASA Astrophysics Data System (ADS)

Icli, Kerem Cagatay; Kocaoglu, Bahadir Can; Ozenbas, Macit

2018-01-01

Fluorine-doped tin dioxide (FTO) thin films were produced via conventional spray pyrolysis and ultrasonic spray pyrolysis (USP) methods using alcohol-based solutions. The prepared films were compared in terms of crystal structure, morphology, surface roughness, visible light transmittance, and electronic properties. Upon investigation of the grain structures and morphologies, the films prepared using ultrasonic spray method provided relatively larger grains and due to this condition, carrier mobilities of these films exhibited slightly higher values. Dye-sensitized solar cells and 10×10 cm modules were prepared using commercially available and USP-deposited FTO/glass substrates, and solar performances were compared. It is observed that there exists no remarkable efficiency difference for both cells and modules, where module efficiency of the USP-deposited FTO glass substrates is 3.06% compared to commercial substrate giving 2.85% under identical conditions. We demonstrated that USP deposition is a low cost and versatile method of depositing commercial quality FTO thin films on large substrates employed in large area dye-sensitized solar modules or other thin film technologies.

Chemical yields from low-temperature pyrolysis of CCA-treated wood

Treesearch

Qirong Fu; Dimitris Argyropolous; Lucian Lucia; David Tilotta; Stan Lebow

2009-01-01

Low-temperature pyrolysis offers a feasible option for wood-waste management and the recovery of a variety of useful chemicals. The effect of chromated copper arsenate (CCA) wood preservative on the yield and composition of various pyrolysis products was investigated in the present research. A novel quantitative 31P nuclear magnetic resonance (...

An investigation on the In doping of ZnO thin films by spray pyrolysis

NASA Astrophysics Data System (ADS)

Mahesh, Devika; Kumar, M. C. Santhosh

2018-04-01

Indium doped zinc oxide (IGZO)thin films are gaining much interest owing to its commercial application as transparent conductive oxide thin films. In the current study thin films indium doped ZnO thin films have been deposited on glass substrates by chemical spray pyrolysis technique with an indium concentration of 1, 2.5 and 4% in Zinc source. The films show a peak shift in the X-Ray Diffraction patterns with varying indium doping concentration. The (101) peak was enhanced for the 2.5 % indium doped films and variation in grain size with the different doping levels was studied. The as-deposited films are uniform and shown high transparency (>90%) in the visible region. Average thicknesses of films are found to be 800nm, calculated using the envelope method. The film with 2.5 % of indium content was found to be highly conducting than the rest, since for the lower and higher concentrations the conductivity was possibly halted by the limit in carrier concentration and indium segregation in the grain boundaries respectively. The enhancement of mobility and carrier concentration was clearly seen in the optimum films.

Influence of solution deposition rate on properties of V2O5 thin films deposited by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Abd-Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

2016-07-01

Vanadium oxide (V2O5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films' crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V2O5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

Synthesis and characterization of ZnO–CuO nanocomposites powder by modified perfume spray pyrolysis method and its antimicrobial investigation

NASA Astrophysics Data System (ADS)

Saravanakkumar, D.; Sivaranjani, S.; Kaviyarasu, K.; Ayeshamariam, A.; Ravikumar, B.; Pandiarajan, S.; Veeralakshmi, C.; Jayachandran, M.; Maaza, M.

2018-03-01

Pure ZnO, ZnO–CuO nanocomposites can be synthesized by using a modified perfume spray pyrolysis method (MSP). The crystallite size of the nanoparticles (NPs) has been observed by X-ray diffraction pattern and is nearly 36 nm. Morphological studies have been analyzed by using Field Emission Scanning Electron Microscopy (FESEM) and its elemental analysis was reported by Elemental X-ray Analysis (EDX); these studies confirmed that ZnO and CuO have hexagonal structure and monoclinic structure respectively. Fourier Transform Infrared (FTIR) spectra revealed that the presence of functional frequencies of ZnO and CuO were observed at 443 and 616 cm‑1. The average bandgap value at 3.25 eV using UV–vis spectra for the entitled composite has described a blue shift that has been observed here. The antibacterial study against both gram positive and negative bacteria has been studied by the disc diffusion method. To the best of our knowledge, it is the first report on ZnO–CuO nanocomposite synthesized by a modified perfume spray pyrolysis method.

Effects of Y/Gd Ratio and Boron Excess on Vacuum Ultraviolet Characteristics and Morphology of (Y,Gd)BO3:Eu Phosphor Particles Prepared by Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Koo, Hye Young; Jung, Dae Soo; Hong, Seung Kwon; Kang, Yun Chan; Jung, Kyeong Youl

2007-06-01

(Y1-xGdx)BO3:Eu (0≤ x≤ 1) phosphor particles were prepared by spray pyrolysis. The optimal amount of boric acid for the high photoluminescence intensity of there particles differed depending on the molar ratio of Y to Gd. With decreasing Y/Gd molar ratio, an increasing amount of excess boric acid was required. The difference in excess quantity of boric acid, which was demanded for the highest photoluminescence intensity according to the Y/Gd ratio, influenced the morphology and mean size of the (Y,Gd)BO3:Eu phosphor particles. The (Y1-xGdx)BO3:Eu (0≤ x≤ 1) phosphor particles had a regular morphology. The mean sizes of the GdBO3:Eu and YBO3:Eu phosphor particles were 1.4 and 1 μm, respectively. The high reactivity of boron and yttrium components produced YBO3:Eu phosphor particles with high photoluminescence intensities by spray pyrolysis using a spray solution with a stoichiometric amount of boric acid.

Modifying Optical Properties of ZnO Films by Forming Zn[subscript 1-x] Co[subscript x]O Solid Solutions via Spray Pyrolysis

ERIC Educational Resources Information Center

Bentley, Anne K.; Weaver, Gabriela C.; Russell, Cianan B.; Fornes, William L.; Choi, Kyoung-Shin; Shih, Susan M.

2007-01-01

A simple and cost-effective experiment for the development and characterization of semiconductors using Uv-vis spectroscopy is described. The study shows that the optical properties of ZnO films can be easily modified by forming Zn[subscript 1-x] Co[subscript x]O solid solutions via spray pyrolysis.

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.

Estimation of risks by chemicals produced during laser pyrolysis of tissues

NASA Astrophysics Data System (ADS)

Weber, Lothar W.; Spleiss, Martin

1995-01-01

Use of laser systems in minimal invasive surgery results in formation of laser aerosol with volatile organic compounds of possible health risk. By use of currently identified chemical substances an overview on possibly associated risks to human health is given. The class of the different identified alkylnitriles seem to be a laser specific toxicological problem. Other groups of chemicals belong to the Maillard reaction type, the fatty acid pyrolysis type, or even the thermally activated chemolysis. In relation to the available different threshold limit values the possible exposure ranges of identified substances are discussed. A rough estimation results in an exposure range of less than 1/100 for almost all substances with given human threshold limit values without regard of possible interactions. For most identified alkylnitriles, alkenes, and heterocycles no threshold limit values are given for lack of, until now, practical purposes. Pyrolysis of anaesthetized organs with isoflurane gave no hints for additional pyrolysis products by fragment interactions with resulting VOCs. Measurements of pyrolysis gases resulted in detection of small amounts of NO additionally with NO2 formation at plasma status.

The route of liquid precursor to ZnO nanoparticles in premixed combustion spray pyrolysis

NASA Astrophysics Data System (ADS)

Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2018-04-01

Zinc oxide nanoparticles had been successfully synthesized by premixed combustion spray pyrolysis. Zinc acetate was dissolved in distilled water was selected as a liquid precursor. Zinc nitrate was also used for comparison the effect of precursor type on the generated particles morphology and the crystallinity. The premixed combustion reaction used liquefied petroleum gas (LPG) mainly consisting of butane and propane as a fuel and compressed air used as an oxidizer. The liquid precursor was atomized using a custom two fluid nozzle to generate droplets. Then, the droplets were sprayed by the flow of air as a carrier gas into the premixed combustion reactor. The zinc precursor was decomposed to zinc oxide due to the high temperature as a result of combustion reaction inside the reactor resulting in nanoparticles formation. The particle size decreased with the increase of the fuel flow rate. In addition, it can be found that at the same flow rate of fuel, the particle size of zinc oxide synthesized using zinc nitrate is larger than that of the use of zinc acetate as a precursor.

The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis

NASA Technical Reports Server (NTRS)

Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Hepp, Aloysius F.

2003-01-01

Ternary single-source precursors were used to deposit CuInS2 thin films using chemical spray pyrolysis. We investigated the effect of the film composition on texture, secondary phase formation, and grain size. As-grown films were most often In-rich. They became more (204/220)-oriented as indium concentration increased, and always contained a yet unidentified secondary phase. The (112)-prefened orientation became more pronounced as the film composition became more Cu-rich. The secondary phase was determined to be an In-rich compound based on composition analysis and Raman spectroscopy. In addition, as-grown Cu-rich (112)-oriented films did not exhibit the In-rich compound. Depositing a thin Cu layer prior to the growth of CuInS2 increased the maximum grain size from - 0.5 micron to - 1 micron, and prevented the formation of the In-rich secondary phase.

Fabrication of functional nanomaterials using flame assisted spray pyrolysis

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

Purwanto, Agus, E-mail: aguspur@uns.ac.id

2014-02-24

Flame assisted spray pyrolysis (FASP) is a class of synthesis method for nanomaterials fabrication. The ability to control nanomaterials characteristics and easy to be-scaled up are the main features of FASP. The crystallinity and particles size of the prepared nanomaterials can be easily controlled by variation of fuel flow rate. The precursor concentration, carrier gas flow rate, and carrier gas can be also used to control the prepared nanomaterials. Energy related nanomaterials preparation uses as the example case in FASP application. These material are yttrium aluminum garnet (YAG:Ce) and tungsten oxide (WO{sub 3}). It needs strategies to produce these materialsmore » into nano-sized order. YAG:Ce nanoparticles only can be synthesized by FASP using the urea addition. The decomposition of urea under high temperature of flame promotes the breakage of YAG:Ce particles into nanoparticles. In the preparation of WO{sub 3}, the high temperature flame can be used to gasify WO{sub 3} solid material. As a result, WO{sub 3} nanoparticles can be prepared easily. Generally, to produce nanoparticles via FASP method, the boiling point of the material is important to determine the strategy which will be used.« less

Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

NASA Astrophysics Data System (ADS)

Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

2017-12-01

Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

Studies on annealed ZnO:V thin films deposited by nebulised spray pyrolysis method

NASA Astrophysics Data System (ADS)

Malini, D. Rachel

2018-04-01

Structural, optical and photoluminescence properties of annealed ZnO:V thin films deposited by nebulized spray pyrolysis technique by varying vanadium concentration are studied. Thickness of thin films varies from 1.52µm to 7.78µm. V2O5, VO2 and ZnO peaks are observed in XRD patterns deposited with high vanadium concentration and the intensity of peaks corresponding to ZnO decreases in those samples. Morphological properties were studied by analysing SEM images and annealed thin films deposited at ZnO:V = 50:50 possess dumb bell shape grains. Emission peaks corresponding to both Augur transition and deep level transition are observed in the PL spectra of the samples.

Synthesis and characterization of cobalt doped nickel oxide thin films by spray pyrolysis method

NASA Astrophysics Data System (ADS)

Sathisha, D.; Naik, K. Gopalakrishna

2018-05-01

Cobalt (Co) doped nickel oxide (NiO) thin films were deposited on glass substrates at a temperature of about 400 °C by spray pyrolysis method. The effect of Co doping concentration on structural, optical and compositional properties of NiO thin films was investigated. X-ray diffraction result shows that the deposited thin films are polycrystalline in nature. Surface morphologies of the deposited thin films were observed by FESEM and AFM. EDS spectra showed the incorporation of Co dopants in NiO thin films. Optical properties of the grown thin films were characterized by UV-visible spectroscopy. It was found that the optical band gap energy and transmittance of the films decrease with increasing Co doping concentration.

Structural, electrical and photovoltaic properties of CoS/Si heterojunction prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

El Radaf, I. M.; Nasr, Mahmoud; Mansour, A. M.

2018-01-01

Au/p-CoS/n-Si/Al heterojunction device was fabricated by spray pyrolysis technique. The structural and morphological features were examined by x-ray diffraction, scanning electron microscope and energy dispersive x-ray analysis. The capacitance-voltage characteristics of the prepared heterojunction were analyzed at room temperature in the dark. The current-voltage characteristics were examined under dark and different incident light intensities 20-100 mW cm-2. The rectification ratio, series resistance, shunt resistance, diode ideality factor and the effective barrier height were determined at dark and illumination conditions. The photovoltaic parameters such as short circuit current density, open circuit voltage, fill factor and power conversion efficiency were calculated at different incident light intensities.

Synthesis of Li2Ti3O7 Anode Materials by Ultrasonic Spray Pyrolysis and Their Electrochemical Properties

PubMed Central

Ogihara, Takashi; Kodera, Takayuki

2013-01-01

Ramsdellite-type lithium titanate (Li2Ti3O7) powders were synthesized by performing ultrasonic spray pyrolysis, and their chemical and physical properties were characterized by performing Scanning Electron Microscope (SEM), powder X-ray Diffraction (XRD), and Inductively Coupled Plasma (ICP) analyses. The as-prepared Li2Ti3O7 precursor powders had spherical morphologies with hollow microstructures, but an irregularly shaped morphology was obtained after calcination above 900 °C. The ramsdellite Li2Ti3O7 crystal phase was obtained after the calcination at 1100 °C under an argon/hydrogen atmosphere. The first rechargeable capacity of the Li2Ti3O7 anode material was 168 mAh/g at 0.1 C and 82 mAh/g at 20 C, and the discharge capacity retention ratio was 99% at 1 C after the 500th cycle. The cycle performance of the Li2Ti3O7 anode was also highly stable at 50 °C, demonstrating the superiority of Li2Ti3O7 anode materials reported previously. PMID:28809274

Influence of solution deposition rate on properties of V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique

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

Abd–Alghafour, N. M., E-mail: na2013bil@gmail.com; Ahmed, Naser M.; Hassan, Zai

Vanadium oxide (V{sub 2}O{sub 5}) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl{sub 3} in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in themore » macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V{sub 2}O{sub 5} film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).« less

Delicate Structural Control of Si-SiOx-C Composite via High-Speed Spray Pyrolysis for Li-Ion Battery Anodes.

PubMed

Lee, Seung Jong; Kim, Hye Jin; Hwang, Tae Hoon; Choi, Sunghun; Park, Sung Hyeon; Deniz, Erhan; Jung, Dae Soo; Choi, Jang Wook

2017-03-08

Despite the high theoretical capacity, silicon (Si) anodes in lithium-ion batteries have difficulty in meeting the commercial standards in various aspects. In particular, the huge volume change of Si makes it very challenging to simultaneously achieve high initial Coulombic efficiency (ICE) and long-term cycle life. Herein, we report spray pyrolysis to prepare Si-SiO x composite using an aqueous precursor solution containing Si nanoparticles, citric acid, and sodium hydroxide (NaOH). In the precursor solution, Si nanoparticles are etched by NaOH with the production of [SiO 4 ] 4- . During the dynamic course of spray pyrolysis, [SiO 4 ] 4- transforms to SiO x matrix and citric acid decomposes to carbon surface layer with the assistance of NaOH that serves as a decomposition catalyst. As a result, a Si-SiO x composite, in which Si nanodomains are homogeneously embedded in the SiO x matrix with carbon surface layer, is generated by a one-pot process with a residence time of only 3.5 s in a flow reactor. The optimal composite structure in terms of Si domain size and Si-to-O ratio exhibited excellent electrochemical performance, such as reversible capacity of 1561.9 mAh g -1 at 0.06C rate and ICE of 80.2% and 87.9% capacity retention after 100 cycles at 1C rate.

Characterization of deposited CdS thin films by Spray Pyrolysis method and used in Cd/CdS/p-Si/Al structure

NASA Astrophysics Data System (ADS)

Özakın, Oǧuzhan; Aktaş, Şeydanur; Güzeldir, Betül; Saǧlam, Mustafa

2017-04-01

In our study, as p-type crystalline Si substrate was used. Omic contact was performed by evaporating Al metal on the matt surface of crystal. On the other surface of it CdS thin film were enlarged with the technique of Spray Pyrolysis. Structural characteristics of the grown thin film was examined SEM and EDAX image. When examining SEM image of CdS thin film were totally covered the p-Si crystal surface of it was nearly homogeneous and The EDAX spectra showed that the expected different ratios metal percent exist in the alloys, approximately. On the CdS films whose surface features were investigated, at 10-7 torr pressure was obtained Cd/CdS/p-Si/Al sandwich structure by evaporating Cd. Firstly, the I-V (current-voltage) characteristics on 80K between 320K at room temperature of this structure was measured. I-V characteristics of the examined at parameters diodes calculation, Thermionic Emission, were used. The characteristic parameters such as barrier height and ideality factor of this structure have been calculated from the forward bias I-V characteristics. Consequently, it was seen that CdS thin film grown on p-Si semiconductor will be used confidently in Cd/p-Si metal-semiconductor contacts thanks to Spray Pyrolysis method.

Preparation of low cost n-ZnO/MgO/p-Si heterojunction photodetector by laser ablation in liquid and spray pyrolysis

NASA Astrophysics Data System (ADS)

Ismail, Raid A.; Khashan, Khawla S.; Jawad, Muslim F.; Mousa, Ali M.; Mahdi, Farah

2018-05-01

In this study, low cost ZnO/Si and ZnO/MgO/Si heterojunction (HJ) photodetectors were fabricated using laser ablation and spray Pyrolysis techniques. MgO nanofibers were synthesized by laser ablation of Mg target in distilled water. Also; the ZnO films were prepared by spray pyrolysis technique. The optical and structural properties of nanostructured MgO were investigated using XRD, SEM and FT-IR. The XRD results showed that the MgO was polycrystalline with cubic structure. SEM investigation confirmed the formation of MgO nanofibers and sub-microparticles. The optical energy gaps of MgO and ZnO were calculated and found to be 5.7 eV and 3.3 eV, respectively. For the electrical properties; responsivity, quantum efficiency, specific detectivity, and speed of response of the photodetector were measured and found to enhance after the insertion of nanostructured MgO film. The Photoresponse results at 3 V reverse bias showed that the maximum responsivity of ZnO/Si and ZnO/MgO/Si photodetectors were 185 and 331 mAW‑1 at 500 nm, respectively. The specific detectivity of ZnO/MgO/Si Photodetector was higher than that of ZnO/Si.

Generation of functional structures by laser pyrolysis of polysilazane

NASA Astrophysics Data System (ADS)

Krauss, Hans-Joachim; Otto, Andreas

2002-06-01

The pyrolysis of polysilazanes by laser power represents an innovative technique for the generation of ceramic-like coatings and structures. The dissolved polysilazanes can be easily applied by painting techniques such as dipping or spraying. In the following pyrolysis the polysilazane layer transforms into an amorphous ceramic-like coating. The laser power is absorbed in the precursor layer, which leads to the latter's ceramization without damaging the substrate by thermal load. While plane laser pyrolysis creates a protective coating, selective pyrolysis creates a raised and adherent ceramic-like structure that remains after the unexposed polymer layer has been removed. The flexibility of a writing laser system in conjunction with a suitable handling system makes it possible to inscribe any kind of 2D structure on nearly any complexly shaped part. Some of the chemical, magnetic, and electrical structure properties can be adjusted by the pyrolysis parameters and special types of filler particles. Especially the possibility to control electric conductivity should make it possible to create structure dielectric films or planar resistors, inductors or capacitors, which are basically written on the surface of the part. Because of their ceramic nature of the structures are resistant against high temperatures and corrosive media. Thus, this new additive structuring technique could finally strike a new path in creating corrosion resistant high- temperature sensors and control systems.

Resistance to Corrosion of Zirconia Coatings Deposited by Spray Pyrolysis in Nitrided Steel

NASA Astrophysics Data System (ADS)

Cubillos, G. I.; Olaya, J. J.; Bethencourt, M.; Cifredo, G.; Blanco, G.

2013-10-01

Coatings of zirconium oxide were deposited onto three types of stainless steel, AISI 316L, 2205, and tool steel AISI D2, using the ultrasonic spray pyrolysis method. The effect of the flux ratio on the process and its influence on the structure and morphology of the coatings were investigated. The coatings obtained, 600 nm thick, were characterized using x-ray diffraction, scanning electron microscopy, confocal microscopy, and atomic force microscopy. The resistance to corrosion of the coatings deposited over steel (not nitrided) and stainless steel nitrided (for 2 h at 823 K) in an ammonia atmosphere was evaluated. The zirconia coating enhances the stainless steel's resistance to corrosion, with the greatest increase in corrosion resistance being observed for tool steel. When the deposition is performed on previously nitrided stainless steel, the morphology of the surface improves and the coating is more homogeneous, which leads to an improved corrosion resistance.

Influence of Annealing Duration on the Growth of V2O5 Nanorods Synthesized by Spray Pyrolysis Technique

NASA Astrophysics Data System (ADS)

Abd-Alghafour, N. M.; Ahmed, Naser M.; Hassan, Z.; Abubakar, D.; Bououdina, M.

2016-06-01

This paper deals with the investigation of annealing effects on the structural, morphological and optical properties of V2O5 nanorods (NRs) grown on the glass substrates by using chemical spray pyrolysis technique. The as-prepared samples were annealed at 500∘ for 40, 60 and 120 min in a quartz tube furnace. The high resolution X-ray diffraction (XRD) analysis revealed V2O5 NRs with preferred orientation along (001) plane. The crystallite size of the V2O5 NRs was increased by increasing the annealing duration. The morphological observations using field emission scanning electron microscope (FESEM) displayed NRs structures whose diameter and length were found to increase with increase of the annealing duration. The transmission electron microscopy (TEM) analysis confirmed the orthorhombic structures of the NRs. The AFM measurements indicated an increase of the average surface roughness by increasing the annealing time. The Raman spectroscopy revealed V-O-V phonon mode in the NRs annealed for 120 min. The optical bandgap was found in the range 2.6-2.58eV and observed to decrease with various duration annealed.

Morphology-controllable of Sn doped ZnO nanorods prepared by spray pyrolysis for transparent electrode application

NASA Astrophysics Data System (ADS)

Hameed, M. Shahul; Princice, J. Joseph; Babu, N. Ramesh; Zahirullah, S. Syed; Deshmukh, Sampat G.; Arunachalam, A.

2018-05-01

Transparent conductive Sn doped ZnO nanorods have been deposited at various doping level by spray pyrolysis technique on glass substrate. The structural, surface morphological and optical properties of these films have been investigated with the help of X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and UV-Vis spectrophotometer respectively. XRD patterns revealed a successful high quality growth of single crystal ZnO nanorods with hexagonal wurtzite structure having (002) preferred orientation. The scanning electron microscope (SEM) image of the prepared films exposed the uniform distribution of Sn doped ZnO nanorod shaped grains. All these films were highly transparent in the visible region with average transmittance of 90%.

Cd-doped ZnO nano crystalline thin films prepared at 723K by spray pyrolysis

NASA Astrophysics Data System (ADS)

Joishy, Sumanth; Rajendra B., V.

2018-04-01

Ternary Zn1-xCdxO(x=0.10, 0.40, 0.70 at.%) thin films of 0.025M precursor concentration have been successfully deposited on preheated (723K) glass substrates using spray pyrolysis route. The structure, morphology and optical properties of deposited films have been characterized by X-ray diffraction, Scanning Electron Microscopy (SEM) and UV-Visible spectrophotometry. X-ray diffraction study shows that the prepared films are polycrystalline in nature. 10% Cd doped ZnO film belongs to the hexagonal wurtzite system and 70% Cd doped ZnO film belongs to the cubic system, although mixed phases were formed for 40% Cd doped ZnO film. The optical transmittance spectra has shown red shift with increasing cadmium content. Optical energy band gap has been reduced with cadmium dopant.

Selective production of chemicals from biomass pyrolysis over metal chlorides supported on zeolite.

PubMed

Leng, Shuai; Wang, Xinde; Cai, Qiuxia; Ma, Fengyun; Liu, Yue'e; Wang, Jianguo

2013-12-01

Direct biomass conversion into chemicals remains a great challenge because of the complexity of the compounds; hence, this process has attracted less attention than conversion into fuel. In this study, we propose a simple one-step method for converting bagasse into furfural (FF) and acetic acid (AC). In this method, bagasse pyrolysis over ZnCl2/HZSM-5 achieved a high FF and AC yield (58.10%) and a 1.01 FF/AC ratio, but a very low yield of medium-boiling point components. However, bagasse pyrolysis using HZSM-5 alone or ZnCl2 alone still remained large amounts of medium-boiling point components or high-boiling point components. The synergistic effect of HZSM-5 and ZnCl2, which combines pyrolysis, zeolite cracking, and Lewis acid-selective catalysis results in highly efficient bagasse conversion into FF and AC. Therefore, our study provides a novel, simple method for directly converting biomass into high-yield useful chemical. Copyright © 2013 Elsevier Ltd. All rights reserved.

Growth and characterization of V2O5 nanorods deposited by spray pyrolysis at low temperatures

NASA Astrophysics Data System (ADS)

Abd-Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai.; Mohammad, Sabah M.; Bououdina, M.

2016-07-01

Vanadium pentoxide (V2O5) nanorods were deposited by spray pyrolysis on preheated glass substrates at low temperatures. The influence of substrate temperature on the crystallization of V2O5 has been investigated. X-ray diffraction analysis (XRD) revealed that the films deposited at Tsub = 300°C were orthorhombic structures with preferential along (001) direction. Formation of nanorods from substrate surface which led to the formation of films with small-sized and rod-shaped nanostructure is observed by field scanning electron microscopy. Optical transmittance in the visible range increases to reach a maximum value of about 80% for a substrate temperature of 350°C. PL spectra reveal one main broad peak centered around 540 nm with high intensity.

Electrical Characteristics and Preparation of Nanostructured Pb(Zr0.5Ti0.5)O3 Films by Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Koo, Horng-Show; Chen, Mi; Hotta, Yoichi; Kawai, Tomoji

2007-07-01

Nanostructured thin films of Pb(Zr0.5Ti0.5)O3 on Pt (1000 Å)/Ti (100 Å)/SiO2 (2000 Å)/Si substrates are prepared by spray pyrolysis and subsequently rapid thermal annealing. Lead nitrate, zirconium nitrate and titanium isopropoxide are used as starting material with ethylene glycol as solvent. The crystal structure of the as-sprayed films are transformed from the amorphous, pyrochlore and multiple phases of pyrochlore and perovskite to the single phase of perovskite as the annealing temperature is increased up to 500 °C. For the formation of single phase perovskite, excess lead of 10 mol % is required to compensate the loss of lead during the processing of the primitive films. The physical characteristics of the resultant films show the dielectric constant (\\varepsilonr) of 400, remanent polarization (2Pr) of 30.0 μC/cm2 and coercive field (2Ec) of 70.0 kV/cm, respectively.

One-Pot Synthesis of CoSex -rGO Composite Powders by Spray Pyrolysis and Their Application as Anode Material for Sodium-Ion Batteries.

PubMed

Park, Gi Dae; Kang, Yun Chan

2016-03-14

A simple one-pot synthesis of metal selenide/reduced graphene oxide (rGO) composite powders for application as anode materials in sodium-ion batteries was developed. The detailed mechanism of formation of the CoSe(x)-rGO composite powders that were selected as the first target material in the spray pyrolysis process was studied. The crumple-structured CoSe(x)-rGO composite powders prepared by spray pyrolysis at 800 °C had a crystal structure consisting mainly of Co0.85 Se with a minor phase of CoSe2. The bare CoSe(x) powders prepared for comparison had a spherical shape and hollow structure. The discharge capacities of the CoSe(x)-rGO composite and bare CoSe(x) powders in the 50th cycle at a constant current density of 0.3 A g(-1) were 420 and 215 mA h g(-1), respectively, and their capacity retentions measured from the second cycle were 80 and 46%, respectively. The high structural stability of the CoSe(x)-rGO composite powders for repeated sodium-ion charge and discharge processes resulted in superior sodium-ion storage properties compared to those of the bare CoSe(x) powders. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CTAB assisted growth and characterization of nanocrystalline CuO films by ultrasonic spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Singh, Iqbal; Kaur, Gursharan; Bedi, R. K.

2011-09-01

An aqueous solution of cupric nitrate trihydrate (Cu(NO 3) 2·3H 2O) modified with cetyltrimetylammonium bromide (CTAB) is used to deposit CuO films on glass substrate by chemical spray pyrolysis technique. The thermal analysis shows that the dried CTAB doped precursor decomposes by an exothermic reaction and suggests that minimum substrate temperature for film deposition should be greater than 270 °C. X-ray diffraction (XRD) studies indicate the formation of monoclinic CuO with preferential orientation along (0 0 2) plane for all film samples. The CTAB used as cationic surfactant in precursor results in the suppression of grain growth in films along the (1 1 0), (0 2 0) and (2 2 0) crystal planes of CuO. Surfactant modified films showed an increase in crystallite size of 14 nm at substrate temperature of 300 °C. The scanning electron micrographs (FESEM) confirm the uniform distribution of facets like grains on the entire area of substrate. CTAB modified films show a significant reduction in the particle agglomeration. Electrical studies of the CuO films deposited at substrate temperature of 300 °C with and without surfactant reveal that the CTAB doping increase the activation energy of conduction by 0.217 eV and room temperature response to ammonia by 9%. The kinetics of the ammonia gas adsorption on the film surface follows the Elovich and Diffusion models.

Catalyzed pyrolysis of grape and olive bagasse. Influence of catalyst type and chemical treatment

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

Encinar, J.M.; Beltran, F.J.; Ramiro, A.

1997-10-01

Catalyzed pyrolysis of grape and olive bagasse under different experimental conditions has been studied. Variables investigated were temperature and type and concentration of catalysts. Experiments were carried out in an isothermal manner. Products of pyrolysis are gases (H{sub 2}, CO, CO{sub 2}, and CH{sub 4}), liquids (methanol, acetone, furfurylic alcohol, phenol, furfural, naphthalene, and o-cresol), and solids (chars). Temperature is a significant variable, yielding increases of fixed carbon content, gases, and to a lesser extent, ash percentage. Catalyst presence also yields increases of solid phase content, but the amount of liquid components decrease. Among catalysts applied those of Fe andmore » Zn are the most advisable to obtain gases. Chemical treatment of bagasses with sulfuric or phosphoric acid washing leads to lower char yields, although fixed carbon content is higher and ash presence diminishes with respect to catalyst pyrolysis without chemical pretreatment. A pyrolysis kinetic study based on gas generation from thermal decomposition of residues has been carried out. From the model proposed, rate constants for the formation of each gas, reaction order of the catalyst, and activation energies were determined.« less

Electrocatalytic upgrading of biomass pyrolysis oils to chemical and fuel

NASA Astrophysics Data System (ADS)

Lam, Chun Ho

The present project's aim is to liquefy biomass through fast pyrolysis and then upgrade the resulting "bio-oil" to renewable fuels and chemicals by intensifying its energy content using electricity. This choice reflects three points: (a) Liquid hydrocarbons are and will long be the most practical fuels and chemical feedstocks because of their energy density (both mass and volume basis), their stability and relative ease of handling, and the well-established infrastructure for their processing, distribution and use; (b) In the U.S., the total carbon content of annually harvestable, non-food biomass is significantly less than that in a year's petroleum usage, so retention of plant-captured carbon is a priority; and (c) Modern technologies for conversion of sunlight into usable energy forms---specifically, electrical power---are already an order of magnitude more efficient than plants are at storing solar energy in chemical form. Biomass fast pyrolysis (BFP) generates flammable gases, char, and "bio-oil", a viscous, corrosive, and highly oxygenated liquid consisting of large amounts of acetic acid and water together with hundreds of other organic compounds. With essentially the same energy density as biomass and a tendency to polymerize, this material cannot practically be stored or transported long distances. It must be upgraded by dehydration, deoxygenation, and hydrogenation to make it both chemically and energetically compatible with modern vehicles and fuels. Thus, this project seeks to develop low cost, general, scalable, robust electrocatalytic methods for reduction of bio-oil into fuels and chemicals.

Chemical and ecotoxicological properties of three bio-oils from pyrolysis of biomasses.

PubMed

Campisi, Tiziana; Samorì, Chiara; Torri, Cristian; Barbera, Giuseppe; Foschini, Anna; Kiwan, Alisar; Galletti, Paola; Tagliavini, Emilio; Pasteris, Andrea

2016-10-01

In view of the potential use of pyrolysis-based technologies, it is crucial to understand the environmental hazards of pyrolysis-derived products, in particular bio-oils. Here, three bio-oils were produced from fast pyrolysis of pine wood and intermediate pyrolysis of corn stalk and poultry litter. They were fully characterized by chemical analysis and tested for their biodegradability and their ecotoxicity on the crustacean Daphnia magna and the green alga Raphidocelis subcapitata. These tests were chosen as required by the European REACH regulation. These three bio-oils were biodegradable, with 40-60% of biodegradation after 28 days, and had EC50 values above 100mgL(-1) for the crustacean and above 10mgL(-1) for the alga, showing low toxicity to the aquatic life. The toxic unit approach was applied to verify whether the observed toxicity could be predicted from the data available for the substances detected in the bio-oils. The predicted values largely underestimated the experimental values. Copyright © 2016 Elsevier Inc. All rights reserved.

Ethylene glycol assisted spray pyrolysis for the synthesis of hollow BaFe12O19 spheres

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

Xu, X; Park, J; Hong, YK

2015-04-01

Hollow spherical BaFe12O19 particles were synthesized by spray pyrolysis from a solution containing ethylene glycol (EG) and precursors at 1000 degrees C. The effects of EG concentration on particle morphology, crystallinity and magnetic properties were investigated. The hollow spherical particles were found to consist of primary particles, and higher EG concentration led to a bigger primary particle size. EG concentration did not show much effect on the hollow particle size. Better crystallinity and higher magnetic coercivity were obtained with higher EG concentration, which is attributed to further crystallization with the heat produced from EG combustion. Saturation magnetization (emu/g) decreased withmore » increasing EG concentration due to residual carbon from EG incomplete combustion, contributing as a non-magnetic phase to the particles. Published by Elsevier B.V.« less

Growth of vertically aligned carbon nanotubes on silicon and quartz substrate by spray pyrolysis of a natural precursor: Turpentine oil

NASA Astrophysics Data System (ADS)

Afre, Rakesh A.; Soga, T.; Jimbo, T.; Kumar, Mukul; Ando, Y.; Sharon, M.

2005-10-01

Vertically aligned carbon nanotubes (VACNTs) were grown by spray pyrolysis of turpentine oil and ferrocene mixture at 700 °C. Using this simple method, we report the successful growth of vertically aligned nanotubes of 300 μm length and diameter in the range of 50-100 nm on Si(1 0 0) substrate. The ferrocene act as an in situ Fe catalyst precursor and forming the nanosize iron particles for formation of VACNTs on Si and quartz substrates. Morphological differences between aligned carbon nanotubes grown on different substrates are studied and discussed by SEM, TEM and Raman spectroscopy characterizations.

Synthesis of ZnO Hexagonal Micro Discs on Glass Substrates Using the Spray Pyrolysis Technique

NASA Astrophysics Data System (ADS)

Ikhmayies, Shadia J.; Zbib, Mohamad B.

2017-07-01

Zinc oxide (ZnO) is an important transparent conducting oxide of potential use in solar cells, electronics, photoelectronics, and sensors. In this work ZnO micro discs were synthesized in thin film form on glass substrates using the low cost spray pyrolysis method. The films were prepared from a precursor solution of ZnCl2 in distilled water at a substrate temperature of 300 ± 5°C. The as-synthesized samples were analyzed with x-ray diffraction, scanning electron microscopy, and x-ray energy dispersive spectroscopy (EDS). The morphology of the films showed randomly distributed micro discs of hexagonal shape. The EDS reports showed that the films contained Cl and Fe. Size analysis was performed using ImageJ software, where the average diameter was found to be 4.8 ± 0.9 μm, and the average thickness was found to be 254 ± 43 nm.

Synthesis of V2O5 microspheres by spray pyrolysis as cathode material for supercapacitors

NASA Astrophysics Data System (ADS)

Yin, Zhendong; Xu, Jie; Ge, Yali; Jiang, Qiaoya; Zhang, Yaling; Yang, Yawei; Sun, Yuping; Hou, Siyu; Shang, Yuanyuan; Zhang, Yingjiu

2018-03-01

Vanadium oxide (V2O5) microspheres have attracted considerable attention in the energy field due to their unique properties such as high stability and electrochemical activity. Here, massive V2O5 microspheres with smooth surface, hollow cavity and uniform particle sizes (0.4–1.5 μm), were synthesized by a facile spray pyrolysis process. Post-treatment at predefined temperatures effectively turned the microsphere shell into stacked nanorods with widths of 100 nm and lengths of 500 nm when processed at 500 °C for 3 h under nitrogen atmosphere, with enhanced crystallinity. When applied as cathode materials for supercapacitors, the post-treated V2O5 microspheres at 500 °C exhibited improved specific capacitance and longer discharge time. This is an effective method to manufacture massive V2O5 microspheres with tailored structure and potential applications in high-performance energy storage materials.

Rates and Mechanisms of Oil Shale Pyrolysis: A Chemical Structure Approach

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

Fletcher, Thomas; Pugmire, Ronald

2015-01-01

Three pristine Utah Green River oil shale samples were obtained and used for analysis by the combined research groups at the University of Utah and Brigham Young University. Oil shale samples were first demineralized and the separated kerogen and extracted bitumen samples were then studied by a host of techniques including high resolution liquid-state carbon-13 NMR, solid-state magic angle sample spinning 13C NMR, GC/MS, FTIR, and pyrolysis. Bitumen was extracted from the shale using methanol/dichloromethane and analyzed using high resolution 13C NMR liquid state spectroscopy, showing carbon aromaticities of 7 to 11%. The three parent shales and the demineralized kerogensmore » were each analyzed with solid-state 13C NMR spectroscopy. Carbon aromaticity of the kerogen was 23-24%, with 10-12 aromatic carbons per cluster. Crushed samples of Green River oil shale and its kerogen extract were pyrolyzed at heating rates from 1 to 10 K/min at pressures of 1 and 40 bar and temperatures up to 1000°C. The transient pyrolysis data were fit with a first-order model and a Distributed Activation Energy Model (DAEM). The demineralized kerogen was pyrolyzed at 10 K/min in nitrogen at atmospheric pressure at temperatures up to 525°C, and the pyrolysis products (light gas, tar, and char) were analyzed using 13C NMR, GC/MS, and FTIR. Details of the kerogen pyrolysis have been modeled by a modified version of the chemical percolation devolatilization (CPD) model that has been widely used to model coal combustion/pyrolysis. This refined CPD model has been successful in predicting the char, tar, and gas yields of the three shale samples during pyrolysis. This set of experiments and associated modeling represents the most sophisticated and complete analysis available for a given set of oil shale samples.« less

Economics evaluation for on-site pyrolysis of kraft lignin to value-added chemicals.

PubMed

Farag, Sherif; Chaouki, Jamal

2015-01-01

This work is part of a series of investigations on pyrolysis of lignin. After obtaining the necessary information regarding the quantity and quality of the obtained products, a first step economics evaluation for converting lignin into chemicals was essential. To accomplish this aim, a pyrolysis plant with a 50t/d capacity was designed, and the total capital investment and operating costs were estimated. Next, the minimal selling price of the obtained dry oil was calculated and the effect of crucial variables on the estimated price was examined. The key result indicates the estimated selling price would not compete with the price of the chemicals that are fossil fuel based, which is primarily due to the high cost of the feedstock. To overcome this challenge, different scenarios for reducing the selling price of the obtained oil, which consequently is helping by taking a place among the fossil fuel based chemicals, were discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nanostructured ZnO films with various morphologies prepared by ultrasonic spray pyrolysis and its growing process

NASA Astrophysics Data System (ADS)

Ma, H. L.; Liu, Z. W.; Zeng, D. C.; Zhong, M. L.; Yu, H. Y.; Mikmekova, E.

2013-10-01

Nanostructured ZnO films were prepared by the ultrasonic spray pyrolysis method using Zn(CH3COO)2·2H2O as a precursor. The effects of substrate temperature (Ts) on the morphology and properties were systematically studied. As the Ts increased from 430 °C to 610 °C, the morphology of the film transforms from closed packed nanosheets to dense nanocrystalline film and then to hexagonal nanorod array. The dense film formed at a temperature of 550 °C has the lowest electric resistivity and highest carrier concentration. The optical transmittance for all prepared samples was higher than 90%. The photoluminescence (PL) properties varied with the Ts due to the internal defect difference. The growth mechanism of ZnO film involves island growth and diffusion, which was evident by observing the samples prepared at various times.

Synthesis of nano-structured tin oxide thin films with faster response to LPG and ammonia by spray pyrolysis

NASA Astrophysics Data System (ADS)

PrasannaKumari, K.; Thomas, Boben

2018-01-01

Nanostructured SnO2 thin film have been efficiently fabricated by spray pyrolysis using atomizers of different types. The structure and morphology of as-prepared samples are investigated by techniques such as x-ray diffraction, and field-emission scanning electron microscopy. Significant morphological changes are observed in films by modifying the precursor atomization as a result of change of spray device. The optical characterization indicates that change in atomization, affects the absorbance and the band gap, following the varied crystallite size. Gas sensing investigations on ultrasonically prepared tin oxide films show NH3 response at operating temperatures lower down to 50 °C. For 1000 ppm of LPG the response at 350 °C for air blast atomizer film is about 99%, with short response and recovery times. The photoluminescence emmision spectra reveal the correlation between atomization process and the quantity of oxygen vacancies present in the samples. The favorable size reduction in microstructure with good crystallinity with slight change in lattice properties suggest their scope in gas sensing applications. On the basis of these characterizations, the mechanism of LPG and NH3 gas sensing of nanostructured SnO2 thin films has been proposed.

Effect of concentration and irradiation on the optical and structural properties of ZnO thin films deposited by spray pyrolysis techniques

NASA Astrophysics Data System (ADS)

Adeoye Victor, Babalola

2017-12-01

This study involves the preparation of ZnO thin films by spray pyrolysis and to investigate the effect of concentration of the film and irradiation on ZnO thin film deposited by spray pyrolysis method deposited at 350 ± 5 °C. The precursor for zinc oxide was produced from zinc acetate (Zn(CH3COO))2. The samples were annealed at 500 °C for 6 h and irradiated using 137Cs 90.998 mCi radiation. They were then characterised using ultra violet-visible spectrophotometry, X-ray Diffractometry (XRD) with Cu-Kα radiation to determine the structure of the film, Four-point probe for electrical properties and Rutherford Backscattering Spectrometry (RBS) were used for the composition of the film. XRD diffraction peaks observed for 0.05 M ZnO were (1 0 0), (0 0 2), (1 0 1) and (1 1 0) planes for the annealed and irradiated annealed ZnO films with no preferential orientation. The as-deposited films have low peaks belonging to (1 0 0), (0 0 2), (1 0 1), (1 1 0) plane and other peaks such as (1 1 2), (2 0 0) and (2 0 1). The results are explained with regard to the irradiation damage introduced to the samples. The as-deposited, annealed and irradiated-annealed films are highly transparent in the visible range of the electromagnetic spectrum with an average percent transmittance values of 85% and present a sharp ultraviolet cut-off at approximately 380 nm for the ZnO thin film.

Concepts of risk assesment of complex chemical mixtures in laser pyrolysis fumes

NASA Astrophysics Data System (ADS)

Weber, Lothar W.; Meier, Thomas H.

1996-01-01

Laser-tissue interaction may generate by energy absorption a complex mixture of gaseous, volatile, semi-volatile and particular substances. At the time about 150 different components are known from IR-laser interaction with different organ tissues like liver, fat, muscle and skin. The laser-tissue interaction process thereby is dominated by heating processes, which is confirmed by the similarity of formed chemical products in comparison with conventional cooking processes for food preparation. With the identified chemical substances and relative amounts in backmind a walk along the think path of risk assessment with special reference to pyrolysis products is given. The main way of intake of pyrolysis products is the inhalative one, which results from the fine aerosols formed and the high spreading energy out of the irradiated source. The liberated amounts of irritative chemicals as (unsaturated) aldehydes, heterocycles of bad odor and possibly cancerogenic acting substances relates to some (mu) g/g of laser vaporized tissue. With regard to this exposure level in a hypothetic one cubic meter volume the occupational limit settings are far away. Even indoor air exposure levels are in nearly all cases underwent, for the content of bad smelling substances forces an effective ventilation. Up to now no laser typical chemical substance could be identified, which was not elsewhere known by frying or baking processes of meat, food or familiar. Starting with the GRAS concept of 1957 the process of risk assessment by modified food products and new ingredients is still improofing. The same process of risk assessment is governing the laser pyrolysis products of mammalian tissues. By use of sufficient suction around the laser tissue source the odor problems as well as the toxicological problems could be solved.

Spray atomization of bio-oil/ethanol blends with externally mixed nozzles

USDA-ARS?s Scientific Manuscript database

Experiments were conducted to investigate the properties of sprays of pyrolysis oil from biomass (bio-oil) using an air assisted atomization nozzle operated without combustion to explore the potential of pyrolysis oil combustion in industrial and home furnaces. Bio-oil was blended with ethanol to im...

Electrical Characteristics and Preparation of (Ba0.5Sr0.5)TiO3 Films by Spray Pyrolysis and Rapid Thermal Annealing

NASA Astrophysics Data System (ADS)

Koo, Horng-Show; Chen, Mi; Ku, Hong-Kou; Kawai, Tomoji

2007-04-01

Functional films of (Ba0.5Sr0.5)TiO3 on Pt (1000 Å)/Ti (100 Å)/SiO2 (2000 Å)/Si substrates are prepared by spray pyrolysis and subsequently rapid thermal annealing. Barium nitrate, strontium nitrate and titanium isopropoxide are used as starting materials with ethylene glycol as solvent. For (Ba0.5Sr0.5)TiO3 functional thin film, thermal characteristics of the precursor powder scratched from as-sprayed films show a remarkable peak around 300-400 °C and 57.7% weight loss up to 1000 °C. The as-sprayed precursor film with coffee-like color and amorphous-like phase is transformed into the resultant film with white, crystalline perovskite phase and characteristic peaks (110) and (100). The resultant films show correspondent increases of dielectric constant, leakage current and dissipation factor with increasing annealing temperatures. The dielectric constant is 264 and tangent loss is 0.21 in the resultant films annealed at 750 °C for 5 min while leakage current density is 1.5× 10-6 A/cm2 in the film annealed at 550 °C for 5 min.

The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis

NASA Technical Reports Server (NTRS)

Jin, Michael H.-C.; Banger, Kulbinder K.; Harris, Jerry D.; Hepp, Aloysius F.

2003-01-01

CuInS2 was deposited by spray pyrolysis using single-source precursors synthesized in-house. Films with either (112) or (204/220) preferred orientation always showed Cu-rich and In-rich composition respectively. The In-rich (204/220)-oriented films always contained a secondary phase evaluated as an In-rich compound, and the hindrance of (112)-oriented grain growth was confirmed by glancing angle X-ray diffraction. In conclusion, only the Cu-rich (112)-oriented films with dense columnar grains can be prepared without the secondary In-rich compound. The effect of extra Cu on the grain size and the solar cell results will be also presented.

Ultrasonic Spray Pyrolysis Deposited Copper Sulphide Thin Films for Solar Cell Applications

PubMed Central

Firat, Y. E.; Yildirim, H.; Erturk, K.

2017-01-01

Polycrystalline copper sulphide (CuxS) thin films were grown by ultrasonic spray pyrolysis method using aqueous solutions of copper chloride and thiourea without any complexing agent at various substrate temperatures of 240, 280, and 320°C. The films were characterized for their structural, optical, and electrical properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), atomic force microscopy (AFM), contact angle (CA), optical absorption, and current-voltage (I-V) measurements. The XRD analysis showed that the films had single or mixed phase polycrystalline nature with a hexagonal covellite and cubic digenite structure. The crystalline phase of the films changed depending on the substrate temperature. The optical band gaps (Eg) of thin films were 2.07 eV (CuS), 2.50 eV (Cu1.765S), and 2.28 eV (Cu1.765S–Cu2S). AFM results indicated that the films had spherical nanosized particles well adhered to the substrate. Contact angle measurements showed that the thin films had hydrophobic nature. Hall effect measurements of all the deposited CuxS thin films demonstrated them to be of p-type conductivity, and the current-voltage (I-V) dark curves exhibited linear variation. PMID:29109807

Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

PubMed Central

Krýsová, Hana; Kavan, Ladislav

2018-01-01

For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20–200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO2 films. The blocking properties of the as-deposited TiO2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar

Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells.

PubMed

Krýsová, Hana; Krýsa, Josef; Kavan, Ladislav

2018-01-01

For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO 2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO 2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20-200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO 2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO 2 films. The blocking properties of the as-deposited TiO 2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO 2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar

Visible light-induced water oxidation on mesoscopic alpha-Fe2O3 films made by ultrasonic spray pyrolysis.

PubMed

Duret, Alexis; Grätzel, Michael

2005-09-15

Alpha-Fe(2)O(3) films having a mesoscopic leaflet type structure were produced for the first time by ultrasonic spray pyrolysis (USP) to explore their potential as oxygen-evolving photoanodes. The target of these studies is to use translucent hematite films deposited on conducting fluorine doped tin oxide (FTO) glass as top electrodes in a tandem cell that accomplishes the cleavage of water into hydrogen and oxygen by sunlight. The properties of layers made by USP were compared to those deposited by conventional spray pyrolysis (SP). Although both types of films show similar XRD and UV-visible and Raman spectra, they differ greatly in their morphology. The mesoscopic alpha-Fe(2)O(3) layers produced by USP consist mainly of 100 nm-sized platelets with a thickness of 5-10 nm. These nanosheets are oriented mainly perpendicularly to the FTO support, their flat surface exposing (001) facets. The mesoscopic leaflet structure has the advantage that it allows for efficient harvesting of visible light, while offering at the same time the very short distance required for the photogenerated holes to reach the electrolyte interface before recombining with conduction band electrons. This allows for water oxidation by the valence band holes even though their diffusion length is only a few nanometers. Distances are longer in the particles produced by SP favoring recombination of photoinduced charge carriers. Open-circuit photovoltage measurements indicate a lower surface state density for the nanoplatelets as compared to the round particles. These factors explain the much higher photoactivity of the USP compared to the SP deposited alpha-Fe(2)O(3) layers. Addition of hydrogen peroxide to the alkaline electrolyte further improves the photocurrent-voltage characteristics of films generated by USP indicating the hole transfer from the valence band of the semiconductor oxide to the adsorbed water to be the rate-limiting kinetic step in the oxygen generation reaction.

Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique

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

Martinez, H.M.; Torres, J., E-mail: njtorress@unal.edu.co; Lopez Carreno, L.D.

2013-01-15

Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO{sub 3} (H{sub 2}O){sub 2} was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into {alpha}-MoO{sub 3}. The optical gap diminishes as the substrate temperaturemore » rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO{sub 3} films' sensitivity was analyzed for CO and H{sub 2}O in the temperature range 160 to 360 K; the results indicate that CO and H{sub 2}O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H{sub 2}O. - Highlights: Black-Right-Pointing-Pointer A low cost technique is used which produces good material. Black-Right-Pointing-Pointer Thin films are prepared using ammonium molybdate tetra hydrated. Black-Right-Pointing-Pointer The control of the physical properties of the samples could be done. Black-Right-Pointing-Pointer A calculation method is proposed to determine the material optical properties. Black-Right-Pointing-Pointer The MoO{sub 3} thin films prepared by spray pyrolysis could be used as gas sensor.« less

Effect of iron doping on structural and microstructural properties of nanocrystalline ZnSnO3 thin films prepared by spray pyrolysis techniques

NASA Astrophysics Data System (ADS)

Pathan, Idris G.; Suryawanshi, Dinesh N.; Bari, Anil R.; Patil, Lalchand A.

2018-05-01

This work presents the effect of iron doping having different volume ratios (1 ml, 2.5 ml and 5 ml) on the structural, microstructural and electrical properties of zinc stannate thin films, prepared by spray pyrolysis method. These properties were characterized with X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). In our study, XRD pattern indicates that ZnSnO3 has a perovskite phase with face exposed hexahedron structure. The electron diffraction fringes observed are in consistent with the peak observed in XRD patterns. Moreover the sensor reported in our study is cost-effective, user friendly and easy to fabricate.

Effect of pyrolysis temperature on the chemical oxidation stability of bamboo biochar.

PubMed

Chen, Dengyu; Yu, Xinzhi; Song, Chao; Pang, Xiaoli; Huang, Jing; Li, Yanjun

2016-10-01

Biochar produced by biomass pyrolysis has the advantage of carbon sequestration. However, some of the carbon atoms in biochar are not very stable. In this study, the effect of pyrolysis temperature on the chemical oxidation stability of bamboo biochar was investigated using the atomic ratios of H/C and O/C, Fourier transform infrared spectroscopy, and potassium dichromate (K2Cr2O7) oxidation spectrophotometric method. The results show that the carbon yield and ratios of H/C and O/C decreased from 71.72%, 0.71, and 0.32 to 38.48%, 0.22, and 0.06, respectively, as the temperature was increased from 300°C to 700°C. Moreover, the main oxygen-containing functional groups gradually decreased, while the degree of aromatization increased accordingly. The biochar showed a better stability at a higher pyrolysis temperature. The proportion of carbon loss, i.e., the amount of oxidized carbon with respect to the total carbon of the biochar, decreased from 16.52% to 6.69% with increasing temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of vacuum annealing on the properties of Cu2SnS3 thin films using low cost ultrasonic spray pyrolysis

NASA Astrophysics Data System (ADS)

Rahaman, Sabina; Sunil, M. Anantha; Shaik, Habibuddin; Ghosh, Kaustab

2018-05-01

Deposition of Cu2SnS3 (CTS) thin films is successfully carried out on soda lime glass substrate using low cost ultrasonic spray pyrolysis technique. Vacuum annealing of CTS films is carried out at different temperatures 350°C, 400°C and 450°C. The present work is to study the effect of annealing temperature on the crystal structure, surface morphology and optical properties of CTS thin films. Structural studies confirm the formation of CTS phase. Raman analysis is carried out to study presence of defects with annealing temperature. Optical studies confirm that film prepared at 450°C temperature is suitable as absorber material for photovoltaic applications.

Scrap tyre pyrolysis: Modified chemical percolation devolatilization (M-CPD) to describe the influence of pyrolysis conditions on product yields.

PubMed

Tan, Vincent; De Girolamo, Anthony; Hosseini, Tahereh; Alhesan, Jameel Aljariri; Zhang, Lian

2018-03-16

This paper attempts to develop a modified chemical percolation devolatilization (M-CPD) model that can include heat transfer, primary pyrolysis and the secondary cracking reactions of volatiles together to describe the pyrolysis of waste scrap tyre chip, as well as to examine the influence of operating conditions on the scrap tyre pyrolysis product yields. Such a study has yet to be conducted in the past, thereby leading to a large knowledge gap failing to understand the pyrolysis of the coarse feedstock appropriately. To validate the developed model, a number of operating parameters including reactor configurations, carrier gas compositions (argon and argon blended with CO 2 and/or steam), scrap tyre chip size (0.5-15.0 mm), terminal pyrolysis temperature (400-800 °C) and heating rate (10 °C/min and 110 °C/min) were examined in a lab-scale fixed-bed pyrolyser, with a particular focus on the secondary cracking extents of the liquid tar. Through both experimental investigation and modelling approach, it was found that significant secondary cracking extent occurred upon the increase in the feedstock size, heating rate and residence time. Upon the fast pyrolysis, the average temperature gap between the centres of the coarse particle and reactor wall could reach a maximum of 115 °C for the tyre chips of 6-15 mm. Consequently, its primary volatiles underwent the secondary cracking reaction at an overall extent of 17% at a terminal temperature of 600 °C and a fast heating rate of 110 °C/min. Consequently, the yield of light gases including methane was increased remarkably. The flow rate of inert carrier gas was also influential in the secondary cracking, in which a maximum tar yield (54 wt%) was reached at a carrier gas flow rate of 1.5  L/min. This indicates the occurrence of secondary cracking has been largely minimised. At a pyrolysis temperature of 600 °C, the addition of CO 2 in the carrier gas had an insignificant effect on the product

Transparent Conducting Mo-Doped CdO Thin Films by Spray Pyrolysis Method for Solar Cell Applications

NASA Astrophysics Data System (ADS)

Helen, S. J.; Devadason, Suganthi; Haris, M.; Mahalingam, T.

2018-04-01

Pure and 3%, 5%, and 7% molybdenum-doped cadmium oxide (CdO) thin films have been prepared on glass substrates preheated to 400°C using a spray pyrolysis technique, then analyzed using x-ray diffraction analysis, field-emission scanning electron microscopy, ultraviolet-visible spectroscopy, and photoluminescence and Hall measurements. The films were found to have polycrystalline nature with cubic structure. The crystallite size was calculated to be ˜ 12 nm for various doping concentrations. Doping improved the optical transparency of the CdO thin film, with the 5% Mo-doped film recording the highest transmittance in the optical region. The energy bandgap deduced from optical studies ranged from 2.38 eV and 2.44 eV for different Mo doping levels. The electrical conductivity was enhanced on Mo doping, with the highest conductivity of 1.74 × 103 (Ω cm)-1 being achieved for the 5% Mo-doped CdO thin film.

Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

NASA Astrophysics Data System (ADS)

Gockeln, Michael; Pokhrel, Suman; Meierhofer, Florian; Glenneberg, Jens; Schowalter, Marco; Rosenauer, Andreas; Fritsching, Udo; Busse, Matthias; Mädler, Lutz; Kun, Robert

2018-01-01

Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIB cost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coated nano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4% after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication.

Efficient acetone sensor based on Ni-doped ZnO nanostructures prepared by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Darunkar, Swapnil S.; Acharya, Smita A.

2018-05-01

Ni-doped ZnO thin film was prepared by home-built spray pyrolysis unit for the detection of acetone at 300°C. Scanning electron microscopic (SEM) images of as-developed thin film of undoped ZnO exhibits large quantity of spherical, non-agglomerated particles with uniform size while in Ni-doped ZnO, particles are quite non-uniform in nature. The particle size estimated by using image J are obtained to be around 20-200 nm. Ni-doping effect on band gaps are determined by UV-vis optical spectroscopy and band gap of Ni-doped ZnO is found to be 3.046 eV. Nickel doping exceptionally enhances the sensing response of ZnO as compared to undoped ZnO system. The major role of the Ni-doping is to create more active sites for chemisorbed oxygen on the surface of sensor and correspondingly, to improve the sensing response. The 6 at.% of Ni-doped ZnO exhibits the highest response (92%) for 100 ppm acetone at 300 °C.

Synthesis of Carbon Nano Materials Originated from Waste Cooking Oil Using a Nebulized Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Arie, A. A.; Hadisaputra, L.; Susanti, R. F.; Devianto, H.; Halim, M.; Enggar, R.; Lee, J. K.

2017-07-01

Synthesis of nanocarbon on snake fruit-peel’s activated carbon from waste cooking oil palm was conducted by a nebulized spray pyrolysis process (NSP) by varying the processing temperature from 650 to 750 °C. Ferrocene was used as a catalyst with constant concentration of 0.015 g/ml of carbon source. The structure of nanocarbon was studied by using scanning electron microscope (SEM),x-ray diffraction (XRD), surface area analyzer and Raman spectroscopy. SEM results showed that the structures of carbon products was in the the form of carbon nanopsheres (CNS). XRD and Raman analysis confirmed the CNS structure. The carbon producs were then tested as electrode’s materials for lithium ion capacitors (LIC) by cyclic voltammetry (CV) instruments. From the CV results the specific capacitance was estimated as 79.57 F / g at a scan rate of 0.1 mV / s and voltage range from 2.5 - 4 V. This study shows that the nano carbons synthesized from the waste cooking oil can be used as prospective electrode materials for LIC.

Fuels and chemicals from equine-waste-derived tail gas reactive pyrolysis oil: technoeconomic analysis, environmental and exergetic life cycle assessment

USDA-ARS?s Scientific Manuscript database

Horse manure, whose improper disposal imposes considerable environmental costs, constitutes an apt feedstock for conversion to renewable fuels and chemicals when tail gas reactive pyrolysis (TGRP) is employed. TGRP is a modification of fast pyrolysis that recycles its non-condensable gases and produ...

Comparative Study on Graded-Barrier AlxGa1‑xN/AlN/GaN/Si Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistor by Using Ultrasonic Spray Pyrolysis Deposition Technique

NASA Astrophysics Data System (ADS)

Lee, Ching-Sung; Hsu, Wei-Chou; Huang, Yi-Ping; Liu, Han-Yin; Yang, Wen-Luh; Yang, Shen-Tin

2018-06-01

Comparative study on a novel Al2O3-dielectric graded-barrier (GB) AlxGa1‑xN/AlN/GaN/Si (x = 0.22 ∼ 0.3) metal-oxide-semiconductor heterostructure field-effect transistor (MOS-HFET) formed by using the ultrasonic spray pyrolysis deposition (USPD) technique has been made with respect to a conventional-barrier (CB) Al0.26Ga0.74N/AlN/GaN/Si MOS-HFET and the reference Schottky-gate HFET devices. The GB AlxGa1‑xN was devised to improve the interfacial quality and enhance the Schottky barrier height at the same time. A cost-effective ultrasonic spray pyrolysis deposition (USPD) method was used to form the high-k Al2O3 gate dielectric and surface passivation on the AlGaN barrier of the present MOS-HFETs. Comprehensive device performances, including maximum extrinsic transconductance (g m,max), maximum drain-source current density (I DS,max), gate-voltage swing (GVS) linearity, breakdown voltages, subthreshold swing (SS), on/off current ratio (I on /I off ), high frequencies, and power performance are investigated.

Evaluation of Nd-Loaded SnO2:F Films Coated via Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Turgut, G.

2018-05-01

Thin layers of single (F)- and double (F/Nd)-incorporated tin oxide have been coated on glass substrate via spray pyrolysis. The structural, morphological, electrical, and optical features of F-incorporated samples were evaluated depending on the Nd loading. X-ray diffraction analysis revealed that samples had tetragonal tin oxide structure with (211) and (200) preferential directions. The crystallite size and strain values varied from 37.98 nm and 1.21 × 10-3 to 52.12 nm and 1.88 × 10-3. Scanning electron microscopy analysis showed that the samples consisted of pyramidal, polyhedral, and needle-shaped granules. The lowest sheet resistance value of 1.22 Ω was found for 1.8 at.% Nd + 25 at.% F-coloaded SnO2. However, the widest optical bandgap of 4.01 eV was observed for the single 25 at.% F-loaded sample. The Urbach tail and figure of merit also changed in the ranges of 664 meV to 1296 meV and 6.4 × 10-2 Ω-1 to 2.3 × 10-3 Ω-1, respectively. The results presented herein indicate that the character of F-doped tin oxide films can be controlled by Nd loading and that these films could be useful for technological applications.

Evaluation of Nd-Loaded SnO2:F Films Coated via Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Turgut, G.

2018-07-01

Thin layers of single (F)- and double (F/Nd)-incorporated tin oxide have been coated on glass substrate via spray pyrolysis. The structural, morphological, electrical, and optical features of F-incorporated samples were evaluated depending on the Nd loading. X-ray diffraction analysis revealed that samples had tetragonal tin oxide structure with (211) and (200) preferential directions. The crystallite size and strain values varied from 37.98 nm and 1.21 × 10-3 to 52.12 nm and 1.88 × 10-3. Scanning electron microscopy analysis showed that the samples consisted of pyramidal, polyhedral, and needle-shaped granules. The lowest sheet resistance value of 1.22 Ω was found for 1.8 at.% Nd + 25 at.% F-coloaded SnO2. However, the widest optical bandgap of 4.01 eV was observed for the single 25 at.% F-loaded sample. The Urbach tail and figure of merit also changed in the ranges of 664 meV to 1296 meV and 6.4 × 10-2 Ω-1 to 2.3 × 10-3 Ω-1, respectively. The results presented herein indicate that the character of F-doped tin oxide films can be controlled by Nd loading and that these films could be useful for technological applications.

Phase transition studies in bismuth ferrite thin films synthesized via spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Goyal, Ankit; Lakhotia, Harish

2013-06-01

Multiferroic are the materials, which combine two or more "ferroic" properties, ferromagnetism, ferroelectricity or ferroelasticity. BiFeO3 is the only single phase multiferroic material which possesses a high Curie temperature (TC ˜ 1103 K), and a high Neel temperature (TN ˜ 643 K) at room temperature. Normally sophisticated methods are being used to deposit thin films but here we have tried a different method Low cost Spray Pyrolysis Method to deposit BiFeO3 thin film of Glass Substrate with rhombohedral crystal structure and R3c space group. Bismuth Ferrite thin films are synthesized using Bismuth Nitrate and Iron Nitrate as precursor solutions. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to study structural analysis of prepared thin films. XRD pattern shows phase formation of BiFeO3 and SEM analysis shows formation of nanocrystals of 200 nm. High Temperature Resistivity measurements were done by using Keithley Electrometer (Two Probe system). Abrupt behavior in temperature range (313 K - 400K) has been observed in resistance studies which more likely suggests that in this transition the structure is tetragonal rather than rhombohedral. BiFeO3 is the potential active material in the next generation of ferroelectric memory devices.

Spray pyrolysis deposition and photoelectrochemical properties of n-type BiOI nanoplatelet thin films.

PubMed

Hahn, Nathan T; Hoang, Son; Self, Jeffrey L; Mullins, C Buddie

2012-09-25

Bismuth oxy-iodide is a potentially interesting visible-light-active photocatalyst; yet there is little research regarding its photoelectrochemical properties. Herein we report the synthesis of BiOI nanoplatelet photoelectrodes by spray pyrolysis on fluorine-doped tin oxide substrates at various temperatures. The films exhibited n-type conductivity, most likely due to the presence of anion vacancies, and optimized films possessed incident photon conversion efficiencies of over 20% in the visible range for the oxidation of I(-) to I(3)(-) at 0.4 V vs Ag/AgCl in acetonitrile. Visible-light photons (λ > 420 nm) contributed approximately 75% of the overall photocurrent under AM1.5G illumination, illustrating their usefulness under solar light illumination. A deposition temperature of 260 °C was found to result in the best performance due to the balance of morphology, crystallinity, impurity levels, and optical absorption, leading to photocurrents of roughly 0.9 mA/cm(2) at 0.4 V vs Ag/AgCl. Although the films performed stably in acetonitrile, their performance decreased significantly upon extended exposure to water, which was apparently caused by a loss of surface iodine and subsequent formation of an insulating bismuth hydroxide layer.

Synthesis of Al2O3 thin films using laser assisted spray pyrolysis (LASP)

NASA Astrophysics Data System (ADS)

Dhonge, Baban P.; Mathews, Tom; Tripura Sundari, S.; Krishnan, R.; Balamurugan, A. K.; Kamruddin, M.; Subbarao, R. V.; Dash, S.; Tyagi, A. K.

2013-01-01

The present study reports the development of a laser assisted ultrasonic spray pyrolysis technique and synthesis of dense optical alumina films using the same. In this technique ultrasonically generated aerosols of aluminum acetylacetonate dissolved in ethanol and a laser beam (Nd:YAG, CW, 1064 nm) were fed coaxially and concurrently through a quartz tube on to a hot substrate mounted on an X-Y raster stage. At the laser focused spot the precursor underwent solvent evaporation and solute sublimation followed by precursor vapor decomposition giving rise to oxide coating, the substrate is rastered to get large surface area coating. The surface morphology revealed coalescence of particles with increase in laser power. The observed particle sizes were 17 nm for films synthesized without laser and 18, 21 and 25 nm for films made with laser at 25, 38 and 50 W, respectively. Refractive index of the films synthesized increased from 1.56 to 1.62 as the laser power increased from 0 to 50 W. The stoichiometry of films was studied using XPS and the increase in interfacial layer thickness with laser power was observed from dynamic SIMS depth profiling and ellipsometry.

Structural and magnetic properties of nanocrystalline NiFe2O4 thin film prepared by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Chavan, Apparao R.; Chilwar, R. R.; Shisode, M. V.; Hivrekar, Mahesh M.; Mande, V. K.; Jadhav, K. M.

2018-05-01

The nanocrystalline NiFe2O4 thin film has been prepared using a spray pyrolysis technique on glass substrate. The prepared thin film was characterized by using X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR), and Field Emission-Scanning Electron Microscopy (FE-SEM) characterization techniques for the structural and microstructural analysis. The magnetic property was measured using vibrating sample magnetometer (VSM) at room temperature. X-ray diffraction studies show the formation of single phase spinel structure of the thin film. The octahedral and tetrahedral vibration in the sample was studied by Fourier transform infrared (FT-IR) spectra. Magnetic hysteresis loop was recorded for thin film at room temperature. At 15 kOe, saturation magnetization (Ms) was found to increase while coercivity (Hc) decreases with thickness of the NiFe2O4 thin film.

Aqueous stream characterization from biomass fast pyrolysis and catalytic fast pyrolysis

DOE PAGES

Black, Brenna A.; Michener, William E.; Ramirez, Kelsey J.; ...

2016-09-05

Here, biomass pyrolysis offers a promising means to rapidly depolymerize lignocellulosic biomass for subsequent catalytic upgrading to renewable fuels. Substantial efforts are currently ongoing to optimize pyrolysis processes including various fast pyrolysis and catalytic fast pyrolysis schemes. In all cases, complex aqueous streams are generated containing solubilized organic compounds that are not converted to target fuels or chemicals and are often slated for wastewater treatment, in turn creating an economic burden on the biorefinery. Valorization of the species in these aqueous streams, however, offers significant potential for substantially improving the economics and sustainability of thermochemical biorefineries. To that end, heremore » we provide a thorough characterization of the aqueous streams from four pilot-scale pyrolysis processes: namely, from fast pyrolysis, fast pyrolysis with downstream fractionation, in situ catalytic fast pyrolysis, and ex situ catalytic fast pyrolysis. These configurations and processes represent characteristic pyrolysis processes undergoing intense development currently. Using a comprehensive suite of aqueous-compatible analytical techniques, we quantitatively characterize between 12 g kg -1 of organic carbon of a highly aqueous catalytic fast pyrolysis stream and up to 315 g kg -1 of organic carbon present in the fast pyrolysis aqueous streams. In all cases, the analysis ranges between 75 and 100% of mass closure. The composition and stream properties closely match the nature of pyrolysis processes, with high contents of carbohydrate-derived compounds in the fast pyrolysis aqueous phase, high acid content in nearly all streams, and mostly recalcitrant phenolics in the heavily deoxygenated ex situ catalytic fast pyrolysis stream. Overall, this work provides a detailed compositional analysis of aqueous streams from leading thermochemical processes -- analyses that are critical for subsequent development of selective

Aqueous stream characterization from biomass fast pyrolysis and catalytic fast pyrolysis

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

Black, Brenna A.; Michener, William E.; Ramirez, Kelsey J.

Here, biomass pyrolysis offers a promising means to rapidly depolymerize lignocellulosic biomass for subsequent catalytic upgrading to renewable fuels. Substantial efforts are currently ongoing to optimize pyrolysis processes including various fast pyrolysis and catalytic fast pyrolysis schemes. In all cases, complex aqueous streams are generated containing solubilized organic compounds that are not converted to target fuels or chemicals and are often slated for wastewater treatment, in turn creating an economic burden on the biorefinery. Valorization of the species in these aqueous streams, however, offers significant potential for substantially improving the economics and sustainability of thermochemical biorefineries. To that end, heremore » we provide a thorough characterization of the aqueous streams from four pilot-scale pyrolysis processes: namely, from fast pyrolysis, fast pyrolysis with downstream fractionation, in situ catalytic fast pyrolysis, and ex situ catalytic fast pyrolysis. These configurations and processes represent characteristic pyrolysis processes undergoing intense development currently. Using a comprehensive suite of aqueous-compatible analytical techniques, we quantitatively characterize between 12 g kg -1 of organic carbon of a highly aqueous catalytic fast pyrolysis stream and up to 315 g kg -1 of organic carbon present in the fast pyrolysis aqueous streams. In all cases, the analysis ranges between 75 and 100% of mass closure. The composition and stream properties closely match the nature of pyrolysis processes, with high contents of carbohydrate-derived compounds in the fast pyrolysis aqueous phase, high acid content in nearly all streams, and mostly recalcitrant phenolics in the heavily deoxygenated ex situ catalytic fast pyrolysis stream. Overall, this work provides a detailed compositional analysis of aqueous streams from leading thermochemical processes -- analyses that are critical for subsequent development of selective

Erosion prevention during highway construction by the use of sprayed on chemicals.

DOT National Transportation Integrated Search

1972-01-01

The purpose of this study was to evaluate the erosion inhibiting potential of nine commercial spray on plastic chemicals. All chemicals were also compared with the conventional method of straw tacked with an asphalt emulsion, and with untreated soil....

Mass production of chemicals from biomass-derived oil by directly atmospheric distillation coupled with co-pyrolysis

NASA Astrophysics Data System (ADS)

Zhang, Xue-Song; Yang, Guang-Xi; Jiang, Hong; Liu, Wu-Jun; Ding, Hong-Sheng

2013-01-01

Production of renewable commodity chemicals from bio-oil derived from fast pyrolysis of biomass has received considerable interests, but hindered by the presence of innumerable components in bio-oil. In present work, we proposed and experimentally demonstrated an innovative approach combining atmospheric distillation of bio-oil with co-pyrolysis for mass production of renewable chemicals from biomass, in which no waste was produced. It was estimated that 51.86 wt.% of distillate just containing dozens of separable organic components could be recovered using this approach. Ten protogenetic and three epigenetic compounds in distillate were qualitatively identified by gas chromatography/mass spectrometry and quantified by gas chromatography. Among them, the recovery efficiencies of acetic acid, propanoic acid, and furfural were all higher than 80 wt.%. Formation pathways of the distillate components in this process were explored. This work opens up a fascinating prospect for mass production of chemical feedstock from waste biomass.

Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures.

PubMed

Ali, Amgad Ahmed; Hashim, Abdul Manaf

2016-12-01

We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively.

Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures

NASA Astrophysics Data System (ADS)

Ali, Amgad Ahmed; Hashim, Abdul Manaf

2016-05-01

We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively.

Electrostatic spraying in the chemical control of Triozoida limbata (Enderlein) (Hemiptera: Triozidae) in guava trees (Psidium guajava L.).

PubMed

Tavares, Rafael M; Cunha, João Par; Alves, Thales C; Bueno, Mariana R; Silva, Sérgio M; Zandonadi, César Hs

2017-06-01

Owing to the difficulty in reaching targets during pesticide applications on guava trees, it is important to evaluate new technologies that may improve pest management. In electrostatic spraying, an electric force is added to the droplets to control their movements such that they are efficiently directed to the target. The present study evaluated the performance of electrostatic and non-electrostatic spraying in the control of the guava psyllid, the deposition of the spray mixture on the leaves and the losses to the soil. The deposition of the spray mixture was up to 2 times greater when using electrostatic spraying in comparison with non-electrostatic application. The losses of the spray mixture to the soil were up to 4 times smaller with the electrostatic spraying. Electrostatic spraying had better control of the psyllid. It was possible to reduce the volume rate of application with electrostatic spraying without adversely affecting the control of the guava psyllid. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Transparent heaters made by ultrasonic spray pyrolysis of SnO2 on soda-lime glass substrates

NASA Astrophysics Data System (ADS)

Ansari, Mohammad; Akbari-Saatloo, Mehdi; Gharesi, Mohsen

2017-12-01

Transparent heaters have become important owing to the increasing demand in automotive and display device manufacturing industries. Indium tin oxide (ITO) is the most commonly used material for production of transparent heaters, but the fabrication cost is high as the indium resources are diminishing fast. This has been the driving force behind the intense research for discovering more durable and cost-effective alternatives. Tin oxide, with its high temperature stability and coexisting high levels of conductivity and transparency, can replace expensive ITO in the fabrication of transparent heaters. Here, we propose tin oxide films deposited using ultrasonic spray pyrolysis as the raw material for the fabrication of transparent heaters. Silver contacts are paste printed on the deposited SnO2 layers, which provide the necessary connections to the external circuitry. Deposition of films having sheet resistance in the 150 Ω/□ range takes only ∼5 minutes and the utilized methods are fully scalable to mass production level. Durability tests, carried out for weeks of continuous operation at different elevated temperatures, demonstrated the long load life of the produced heaters.

Transparent nanostructured Fe-doped TiO2 thin films prepared by ultrasonic assisted spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Rasoulnezhad, Hossein; Hosseinzadeh, Ghader; Ghasemian, Naser; Hosseinzadeh, Reza; Homayoun Keihan, Amir

2018-05-01

Nanostructured TiO2 and Fe-doped TiO2 thin films with high transparency were deposited on glass substrate through ultrasonic-assisted spray pyrolysis technique and were used in the visible light photocatalytic degradation of MB dye. The resulting thin films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence spectroscopy, x-ray diffraction (XRD), and UV-visible absorption spectroscopy techniques. Based on Raman spectroscopy results, both of the TiO2 and Fe-doped TiO2 films have anatase crystal structure, however, because of the insertion of Fe in the structure of TiO2 some point defects and oxygen vacancies are formed in the Fe-doped TiO2 thin film. Presence of Fe in the structure of TiO2 decreases the band gap energy of TiO2 and also reduces the electron–hole recombination rate. Decreasing of the electron–hole recombination rate and band gap energy result in the enhancement of the visible light photocatalytic activity of the Fe-doped TiO2 thin film.

Mass production of chemicals from biomass-derived oil by directly atmospheric distillation coupled with co-pyrolysis

PubMed Central

Zhang, Xue-Song; Yang, Guang-Xi; Jiang, Hong; Liu, Wu-Jun; Ding, Hong-Sheng

2013-01-01

Production of renewable commodity chemicals from bio-oil derived from fast pyrolysis of biomass has received considerable interests, but hindered by the presence of innumerable components in bio-oil. In present work, we proposed and experimentally demonstrated an innovative approach combining atmospheric distillation of bio-oil with co-pyrolysis for mass production of renewable chemicals from biomass, in which no waste was produced. It was estimated that 51.86 wt.% of distillate just containing dozens of separable organic components could be recovered using this approach. Ten protogenetic and three epigenetic compounds in distillate were qualitatively identified by gas chromatography/mass spectrometry and quantified by gas chromatography. Among them, the recovery efficiencies of acetic acid, propanoic acid, and furfural were all higher than 80 wt.%. Formation pathways of the distillate components in this process were explored. This work opens up a fascinating prospect for mass production of chemical feedstock from waste biomass. PMID:23350028

Understanding and Controlling Lignocellulosic Pyrolysis for the Production of Renewable Fuel and Chemical Precursors

NASA Astrophysics Data System (ADS)

Pecha, Michael Brennan

Pyrolysis is a technology for producing fuels, chemicals, and engineered carbons from renewable feedstocks like lignocellulosic biomass. This work aims to address some of the scientific and technical hurdles that need to be overcome to control the products of pyrolysis. The first section aims to address knowledge gaps regarding primary pyrolysis reactions; in this study, pine wood was acid washed and small amounts of acid were impregnated into the biomass prior to pyrolysis. Results showed that the acid mitigated fragmentation reactions caused by residual metals and had further effect on production of sugars and oligomeric lignin products. The next section aims to address knowledge gaps regarding what reactions occur in the liquid intermediate phase in biomass pyrolysis; in these studies, a novel reactor system was built which could perform thin film fast pyrolysis studies at different pressures from 4 mbar to 1 atm with cellulose, milled wood lignin, and hybrid poplar wood. The reactor was carefully characterized to achieve comparable data between the different pressures. The use of vacuum allowed for control of the residence time of cellobiosan (one of cellulose oligomeric products) in the liquid intermediate. In the vacuum cellulose pyrolysis studies, a high resolution FT-ICR-MS was used for the first time to explore reaction chemistry for this system. The Van-Krevelen diagram of the resulting oligomeric products proved to be a powerful tool to study secondary reactions in the liquid intermediate. Our results show that the secondary reactions in the liquid intermediate are dominated by dehydration, fragmentation, and cross-linking reactions. The final section aims to address single particle external heat transfer problems; in this study, 500 microm long particles of pine and aspen poplar with realistic pore and surface morphologies were modeled in COMSOL to determine how microstructure effects the external heat transfer coefficients in the laminar flow regime

Method to synthesize and produce thin films by spray pyrolysis

DOEpatents

Squillante, Michael R.

1982-06-22

Forming a film by spraying onto a heated substrate an atomized solution containing the appropriate salt of a constituent element of the film and a highly soluble (i.e., greater than 1 M) organic acid in sufficient amount to reduce the oxidation state of at least one solute element of the spray solution after contacting the heated substrate.

Extent of pyrolysis impacts on fast pyrolysis biochar properties.

PubMed

Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

2012-01-01

A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

LETTER TO THE EDITOR: Green emission and bandgap narrowing due to two-photon excitation in thin film CdS formed by spray pyrolysis

NASA Astrophysics Data System (ADS)

Ullrich, B.; Schroeder, R.

2001-08-01

Thin (10 µm) film CdS on Pyrex® formed by spray pyrolysis is excited below the gap at 804 nm with 200 fs laser pulses at room temperature. Excitation intensities up to 250 GW cm-2 evoke green bandgap emission due to two-photon transitions. This two-photon photoluminescence does not show a red emission contribution in contrast to the single-photon excited emission, which is dominated by broad emission in the red spectral range. It is demonstrated that two-photon excitation causes photo-induced bandgap narrowing due to Debye screening. At 250 GW cm-2 bandgap narrowing of 47 meV is observed, which corresponds to an excited electron density of 1.6×1018 cm-3.

Synthesis and photocatalytic property of Zinc Oxide (ZnO) fine particle using flame spray pyrolysis method

NASA Astrophysics Data System (ADS)

Widiyandari, Hendri; Ayu Ketut Umiati, Ngurah; Dwi Herdianti, Rizki

2018-05-01

Advance oxidation process (AOP) using photocatalysis constitute a promising technology for the treatment of wastewaters containing non-easily removable organic compound. Zinc oxide (ZnO) is one of efficient photocatalyst materials. This research reported synthesis of ZnO fine particle from zinc nitrate hexahydrate using Flame Spray Pyrolysis (FSP) method. In this method, oxygen (O2) gas were used as oxidizer and LPG (liquid petroleum gas) were used as fuel. The effect of O2 gas flow rate during ZnO particle fabrication to the microstructure, optical and photocatalytic properties were systematically discussed. The photocatalytic activity of ZnO was tested for the degradation of amaranth dye with initial concentration of 10 ppm under irradiation of solar simulator. The rate of decrease in amaranth concentration was measured using UV-Visible spectrophotometer. The ZnO synthesized using FSP has a hexagonal crystalline structure. Scanning electron microscope images showed that ZnO has a spherical formed which was the mixture of solid and hollow particles. The optimum condition for amaranth degradation was shown by ZnO produced at a flow rate of 1.5 L/min which able to degrade amaranth dye up to 95,3 % at 75 minutes irradiation.

Pyrolysis of waste tyres: A review

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

Williams, Paul T., E-mail: p.t.williams@leeds.ac.uk

2013-08-15

Graphical abstract: - Highlights: • Pyrolysis of waste tyres produces oil, gas and char, and recovered steel. • Batch, screw kiln, rotary kiln, vacuum and fluidised-bed are main reactor types. • Product yields are influenced by reactor type, temperature and heating rate. • Pyrolysis oils are complex and can be used as chemical feedstock or fuel. • Research into higher value products from the tyre pyrolysis process is reviewed. - Abstract: Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest inmore » pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H{sub 2}, C{sub 1}–C{sub 4} hydrocarbons, CO{sub 2}, CO and H{sub 2}S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale.« less

Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS

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

Antonakou, E.V.; Kalogiannis, K.G.; Stephanidis, S.D.

Highlights: • Thermal and catalytic pyrolysis is a powerful method for recycling of WEEEs. • Liquid products obtained from the pyrolysis of PC or HIPS found in waste CDs are very different. • Mainly phenols are obtained from pyrolysis PC based wastes while aromatics from HIPS. • Use of MgO catalyst increases the amount of phenols from CD recycling compared to ZSM-5. • Use of MgO or ZSM-5 catalysts reduces the amount of styrene recovered from HIPS. - Abstract: Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or variousmore » useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.« less

Photoelectrochemical performance of W-doped BiVO4 thin films deposited by spray pyrolysis

NASA Astrophysics Data System (ADS)

Holland, S. Keith; Dutter, Melissa R.; Lawrence, David J.; Reisner, Barbara A.; DeVore, Thomas C.

2014-01-01

The effects of tungsten doping and hydrogen annealing on the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) photoanodes for solar water splitting were studied. Thin films of BiVO were deposited on indium tin oxide-coated glass slides by ultrasonic spray pyrolysis of an aqueous solution containing bismuth nitrate and vanadium oxysulfate. Tungsten doping was achieved by adding either silicotungstic acid (STA) or ammonium metatungstate (AMT) to the precursor. The 1.7- to 2.2-μm-thick films exhibited a highly porous microstructure. Undoped films that were reduced at 375°C in 3% H exhibited the largest photocurrent densities under 0.1 W cm-2 AM1.5 illumination, where photocurrent densities of up to 1.3 mA cm-2 at 0.5 V with respect to Ag/AgCl were achieved. Films doped with 1% or 5% (atomic percent) tungsten from either STA or AMT exhibited reduced PEC performance and greater sample-to-sample performance variations. Powder x-ray diffraction data indicated that the films continue to crystallize in the monoclinic polymorph at low doping levels but crystallize in the tetragonal scheelite structure at higher doping. It is surmised that the phase and morphology differences promoted by the addition of W during the deposition process reduced the PEC performance as measured by photovoltammetry.

Tailoring of optical band gap by varying Zn content in Cd{sub 1-x}Zn{sub x}S thin films prepared by spray pyrolysis method

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

Kumar, Vipin, E-mail: vipinkumar28@yahoo.co.in; Sharma, D. K.; Agrawal, Sonalika

Cd{sub 1-X}Zn{sub X}S thin films (X = 0.2, 0.4, 0.6, 0.8) have been grown on glass substrate by spray pyrolysis technique using equimolar concentration aqueous solution of cadmium chloride, zinc acetate and thiourea. Prepared thin films have been characterized by UV-VIS spectrophotometer. The optical band gap of the films has been studied by transmission spectra in wavelength range 325-600nm. It has been observed that optical band gap increases with increasing zinc concentration. The optical band gap of these thin films varies from 2.59 to 3.20eV with increasing Zn content.

Chemical spray pyrolyzed kesterite Cu2ZnSnS4 (CZTS) thin films

NASA Astrophysics Data System (ADS)

Khalate, S. A.; Kate, R. S.; Deokate, R. J.

2018-04-01

Pure kesterite phase thin films of Cu2ZnSnS4 (CZTS) were synthesized at different substrate temperatures using sulphate precursors by spray pyrolysis method. The significance of synthesis temperature on the structural, morphological and optical properties has been studied. The X-ray analysis assured that synthesized CZTS thin films showing pure kesterite phase. The value of crystallite size was found maximum at the substrate temperature 400 °C. At the same temperature, microstructural properties such as dislocation density, micro-strain and stacking fault probability were found minimum. The morphological examination designates the development of porous and uniform CZTS thin films. The synthesized CZTS thin films illustrate excellent optical absorption (105 cm-1) in the visible band and the optical band gap varies in the range of 1.489 eV to 1.499 eV.

Fabricate heterojunction diode by using the modified spray pyrolysis method to deposit nickel-lithium oxide on indium tin oxide substrate.

PubMed

Wu, Chia-Ching; Yang, Cheng-Fu

2013-06-12

P-type lithium-doped nickel oxide (p-LNiO) thin films were deposited on an n-type indium tin oxide (ITO) glass substrate using the modified spray pyrolysis method (SPM), to fabricate a transparent p-n heterojunction diode. The structural, optical, and electrical properties of the p-LNiO and ITO thin films and the p-LNiO/n-ITO heterojunction diode were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectroscopy, Hall effect measurement, and current-voltage (I-V) measurements. The nonlinear and rectifying I-V properties confirmed that a heterojunction diode characteristic was successfully formed in the p-LNiO/n-ITO (p-n) structure. The I-V characteristic was dominated by space-charge-limited current (SCLC), and the Anderson model demonstrated that band alignment existed in the p-LNiO/n-ITO heterojunction diode.

Understanding the fast pyrolysis of lignin.

PubMed

Patwardhan, Pushkaraj R; Brown, Robert C; Shanks, Brent H

2011-11-18

In the present study, pyrolysis of corn stover lignin was investigated by using a micro-pyrolyzer coupled with a GC-MS/FID (FID=flame ionization detector). The system has pyrolysis-vapor residence times of 15-20 ms, thus providing a regime of minimal secondary reactions. The primary pyrolysis product distribution obtained from lignin is reported. Over 84 % mass balance and almost complete closure on carbon balance is achieved. In another set of experiments, the pyrolysis vapors emerging from the micro-pyrolyzer are condensed to obtain lignin-derived bio-oil. The chemical composition of the bio-oil is analyzed by using GC-MS and gel permeation chromatography techniques. The comparison between results of two sets of experiments indicates that monomeric compounds are the primary pyrolysis products of lignin, which recombine after primary pyrolysis to produce oligomeric compounds. Further, the effect of minerals (NaCl, KCl, MgCl(2), and CaCl(2)) and temperature on the primary pyrolysis product distribution is investigated. The study provides insights into the fundamental mechanisms of lignin pyrolysis and a basis for developing more descriptive models of biomass pyrolysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Co-pyrolysis of polypropylene waste with Brazilian heavy oil.

PubMed

Assumpção, Luiz C F N; Carbonell, Montserrat M; Marques, Mônica R C

2011-01-01

To evaluate the chemical recycling of plastic residues, co-pyrolysis of polypropylene (PP) waste with Brazilian crude oil was evaluated varying the temperature (400°C to 500°C) and the amount of PP fed to the reactor. The co-pyrolysis of plastic waste in an inert atmosphere provided around 80% of oil pyrolytic, and of these, half represent the fraction of diesel oil. This study can be used as a reference in chemical recycling of plastics, specially associated with plastics co-pyrolysis.

Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS.

PubMed

Antonakou, E V; Kalogiannis, K G; Stephanidis, S D; Triantafyllidis, K S; Lappas, A A; Achilias, D S

2014-12-01

Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microemulsion flame pyrolysis for hopcalite nanoparticle synthesis: a new concept for catalyst preparation.

PubMed

Biemelt, T; Wegner, K; Teichert, J; Kaskel, S

2015-04-07

A new route to highly active hopcalite catalysts via flame spray pyrolysis of an inverse microemulsion precursor is reported. The nitrate derived nanoparticles are around 15 nm in diameter and show excellent conversion of CO under ambient conditions, outperforming commercial reference hopcalite materials produced by co-precipitation.

Comparison of the effect of wet and dry torrefaction on chemical structure and pyrolysis behavior of corncobs.

PubMed

Zheng, Anqing; Zhao, Zengli; Chang, Sheng; Huang, Zhen; Zhao, Kun; Wei, Guoqiang; He, Fang; Li, Haibin

2015-01-01

Wet and dry torrefaction of corncobs was conducted in high-pressure reactor and tube-type reactor, respectively. Effect of wet and dry torrefaction on chemical structure and pyrolysis behavior of corncobs was compared. The results showed that hemicellulose could be effectively removed from corncobs by torrefaction. However, dry torrefaction caused severe degradation of cellulose and the cross-linking and charring of corncobs. X-ray diffraction analysis revealed that crystallinity degree of corncobs was evidently enhanced during wet torrefaction, but reduced during dry torrefaction as raising treatment temperature. In thermogravimetric analysis, wet torrefied corncobs produced less carbonaceous residues than raw corncobs, while dry torrefied corncobs gave much more residues owing to increased content of acid insoluble lignin. Pyrolysis-gas chromatography/mass spectroscopy analysis indicated that wet torrefaction significantly promoted levoglucosan yield owing to the removal of alkali metals. Therefore, wet torrefaction can be considered as a more effective pretreatment method for fast pyrolysis of biomass. Copyright © 2014 Elsevier Ltd. All rights reserved.

Photoelectrochemical performance of W-doped BiVO4 thin-films deposited by spray pyrolysis

NASA Astrophysics Data System (ADS)

Holland, Stephen K.; Dutter, Melissa R.; Lawrence, David J.; Reisner, Barbara A.; DeVore, Thomas C.

2013-09-01

The effect of tungsten doping and hydrogen annealing treatments on the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) photoanodes for solar water splitting was studied. Thin films of BiVO4 were deposited on ITO-coated glass slides by ultrasonic spray pyrolysis of an aqueous solution containing bismuth nitrate and vanadium oxysulfate. Tungsten doping was achieved by adding either silicotungstic acid (STA) or ammonium metatungstate (AMT) in the aqueous precursor. The 1.7 μm - 2.2 μm thick films exhibited a highly porous microstructure. Undoped films that were reduced at 375 ºC in 3% H2 exhibited the largest photocurrent densities under 0.1 W cm-2 AM1.5 illumination. This performance enhancement was believed to be due to the formation of oxygen vacancies, which are shallow electron donors, in the films. Films doped with 1% or 5% tungsten from either STA or AMT exhibited reduced photoelectrochemical performance and greater sample-to-sample performance variations. Powder X-ray diffraction data of the undoped films indicated that they were comprised primarily of the monoclinic scheelite phase while unidentified phases were also present. Scanning electron microscopy showed slightly different morphology characteristics for the Wdoped films. It is surmised that the addition of W in the deposition process promoted the morphology differences and the formation of different phases, thus reducing the PEC performance of the photoanode samples. Significant PEC performance variability was also observed among films deposited using the described process.

High-resolution mass spectrometric analysis of biomass pyrolysis vapors

DOE PAGES

Christensen, Earl; Evans, Robert J.; Carpenter, Daniel

2017-01-19

Vapors generated from the pyrolysis of lignocellulosic biomass are made up of a complex mixture of oxygenated compounds. Direct analysis of these vapors provides insight into the mechanisms of depolymerization of cellulose, hemicellulose, and lignin as well as insight into reactions that may occur during condensation of pyrolysis vapors into bio-oil. Studies utilizing pyrolysis molecular beam mass spectrometry have provided valuable information regarding the chemical composition of pyrolysis vapors. Mass spectrometers generally employed with these instruments have low mass resolution of approximately a mass unit. The presence of chemical species with identical unit mass but differing elemental formulas cannot bemore » resolved with these instruments and are therefore detected as a single ion. In this study we analyzed the pyrolysis vapors of several biomass sources using a high-resolution double focusing mass spectrometer. High-resolution analysis of pyrolysis vapors allowed for speciation of several compounds that would be detected as a single ion with unit mass resolution. Lastly, these data not only provide greater detail into the composition of pyrolysis vapors but also highlight differences between vapors generated from multiple biomass feedstocks.« less

Rapid analysis of the chemical composition of agricultural fibers using near infrared spectroscopy and pyrolysis molecular beam mass spectrometry

Treesearch

Stephen S. Kelley; Roger M. Rowell; Mark Davis; Cheryl K. Jurich; Rebecca Ibach

2004-01-01

The chemical composition of a variety of agricultural biomass samples was analyzed with near infrared spectroscopy and pyrolysis molecular beam mass spectroscopy. These samples were selected from a wide array of agricultural residue samples and included residues that had been subjected to a variety of di2erent treatments including solvent extractions and chemical...

Effect of boric acid on the properties of Li{sub 2}MnO{sub 3}·LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders prepared by large-scale spray pyrolysis with droplet classifier

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

Hong, Young Jun; Choi, Seung Ho; Sim, Chul Min

2012-12-15

Graphical abstract: Display Omitted Highlights: ► Spherical shape Li{sub 2}MnO{sub 3}·LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders are prepared by large-scale spray pyrolysis with droplet classifier. ► Boric acid improves the morphological and electrochemical properties of the composite cathode powders. ► The discharge capacity of the composite cathode powders decreases from 217 to 196 mAh g{sup −1} by the 30th cycle. -- Abstract: Spherically shaped 0.3Li{sub 2}MnO{sub 3}·0.7LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders with filled morphology and narrow size distribution are prepared by large-scale spray pyrolysis. A droplet classification reduces the standard deviation of the size distribution of themore » composite cathode powders. Addition of boric acid improves the morphological properties of the product powders by forming a lithium borate glass material with low melting temperature. The optimum amount of boric acid dissolved in the spray solution is 0.8 wt% of the composite powders. The powders prepared from the spray solution with 0.8 wt% boric acid have a mixed layered crystal structure comprising Li{sub 2}MnO{sub 3} and LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} phases, thus forming a composite compound. The initial charge and discharge capacities of the composite cathode powders prepared from the 0.8 wt% boric acid spray solution are 297 and 217 mAh g{sup −1}, respectively. The discharge capacity of the powders decreases from 217 to 196 mAh g{sup −1} by the 30th cycle, in which the capacity retention is 90%.« less

Quantum-dot-sensitized solar cells fabricated by the combined process of the direct attachment of colloidal CdSe quantum dots having a ZnS glue layer and spray pyrolysis deposition.

PubMed

Im, Sang Hyuk; Lee, Yong Hui; Seok, Sang Il; Kim, Sung Woo; Kim, Sang-Wook

2010-12-07

We were able to attach CdSe quantum dots (QDs) having a ZnS inorganic glue layer directly to a mesoporous TiO(2) (mp-TiO(2)) surface by spray coating and thermal annealing. Quantum-dot-sensitized solar cells based on CdSe QDs having ZnS as the inorganic glue layer could easily transport generated charge carriers because of the intimate bonding between CdSe and mp-TiO(2). The application of spray pyrolysis deposition (SPD) to obtain additional CdSe layers improved the performance characteristics to V(oc) = 0.45 V, J(sc) = 10.7 mA/cm(2), fill factor = 35.8%, and power conversion efficiency = 1.7%. Furthermore, ZnS post-treatment improved the device performance to V(oc) = 0.57 V, J(sc) = 11.2 mA/cm(2), fill factor = 35.4%, and power conversion efficiency = 2.2%.

Chemical spray pyrolysis of Tl-Ba-Ca-Cu-O high-T(sub c) superconductors for high-field bitter magnets

NASA Technical Reports Server (NTRS)

Derochemont, L. Pierre; Zhang, John G.; Squillante, Michael R.; Hermann, A. M.; Duan, H. M.; Andrews, Robert J.; Kelliher, Warren C.

1991-01-01

The deposition of Tl-Ba-Ca-Cu-O thick films by spray pyrolyzing a Ba-Ca-Cu-O precursor film and diffusing thallium into the film to form the superconducting phase is examined. This approach was taken to reduce exposure to thallium and its health and safety hazards. The Tl-Ba-Ca-Cu-O system was selected because it has very attractive features which make it appealing to device and manufacturing engineering. Tl-Ba-Ca-Cu-O will accommodate a number of superconducting phases. This attribute makes it very forgiving to stoichiometric fluctuations in the bulk and film. It has excellent thermal and chemical stability, and appears to be relatively insensitive to chemical impurities. Oxygen is tightly bound into the systems, consequently there is no orthorhombic (conductor) to tetragonal (insulator) transition which would affect a component's lifetime. More significantly, the thallium based superconductors appear to have harder magnetic properties than the other high-Tc oxide ceramics. Estimates using magnetoresistance measurements indicate that at 77 K Tl2Ba2CaCu2O10 will have an upper critical field, H(sub c2) fo 26 Tesla for applied fields parallel to the c-axis and approximately 1000 Tesla for fields oriented in the a-b plane. Results to date have shown that superconducting films can be reproducibly deposited on 100 oriented MgO substrates. One film had a zero resistance temperature of 111.5 K. Furthermore, x ray diffraction analysis of the films showed preferential c-axis orientation parallel to the plane of the substrate. These results have now made it possible to consider the manufacture of a superconducting tape wire which can be configured into a topology useful for high-field magnet designs. The research which leads to the preparation of these films and plans for further development are reviewed.

Growth of nanocrystalline Cu2ZnSnS4 thin films using the spray pyrolysis technique and their characterization

NASA Astrophysics Data System (ADS)

Chandel, Tarun; Halaszova, Sona; Prochazka, Michal; Hasko, Daniel; Velic, Dusan; Thakur, Vikas; Dwivedi, Shailendra Kumar; Zaman, M. Buhanuz; Rajaram, Poolla

2018-05-01

Nanocrystalline thin films of Cu2ZnSnS4 (CZTS) were grown on the glass substrates using the spray pyrolysis technique. The films were grown at a substrate temperature of 300 °C after which they were annealed at 350 °C in vacuum. X-ray diffraction (XRD) studies showed that the films crystallized in the kesterite structure. Energy dispersive analysis of X-rays (EDAX) studies showed that the films possess the desired stoichiometry i.e. the proportion of Cu:Zn:Sn:S in the CZTS solid solution is close to 2:1:1:4. Secondary Ions Mass Spectroscopy (SIMS) depth profiling confirmed the uniformity in elemental composition along the depth of the films. SEM studies showed that the films are covered with CZTS particles forming sheet like structures. AFM studies show that the size of the particles on the surface of the films is around 10-15 nm. UV-VIS-NIR transmission spectra were used to determine the optical band gap of the CZTS films which was found to be around 1.55eV.

Screen-printed (La,Sr)CrO3 coatings on ferritic stainless steel interconnects for solid oxide fuel cells using nanopowders prepared by means of ultrasonic spray pyrolysis

NASA Astrophysics Data System (ADS)

Brylewski, Tomasz; Dabek, Jaroslaw; Przybylski, Kazimierz; Morgiel, Jerzy; Rekas, Mieczyslaw

2012-06-01

In order to protect the cathode from chromium poisoning and improve electrical resistance, a perovskite (La,Sr)CrO3 coating was deposited on the surface of a DIN 50049 ferritic stainless steel by means of the screen-printing method, using a paste composed of an ultra-fine powder prepared via ultrasonic spray pyrolysis. Investigations of the oxidation process of the coated steel in air and the Ar-H2-H2O gas mixture at 1073 K for times up to 820 h showed high compactness of the protective film, good adhesion to the metal substrate, as well as area specific resistance (ASR) at a level acceptable for metallic SOFC interconnect materials. The microstructure, nanostructure, phase composition of the thick film, and in particular the film/substrate interface, were examined via chemical analyses by means of SEM-EDS and TEM-SAD. It was shown that the (La,Sr)CrO3 coating interacts with the steel during long-term thermal oxidation in the afore-mentioned conditions and intermediate, chromia-rich and/or spinel multilayer interfacial zones are formed. Cr-vaporization tests showed that the (La,Sr)CrO3 coating may play the role of barriers that decrease the volatilization rate of chromia species.

Auto shredder residue recycling: Mechanical separation and pyrolysis.

PubMed

Santini, Alessandro; Passarini, Fabrizio; Vassura, Ivano; Serrano, David; Dufour, Javier; Morselli, Luciano

2012-05-01

Directive 2000/53/EC sets a goal of 85% material recycling from end-of-life vehicles (ELVs) by the end of 2015. The current ELV recycling rate is around 80%, while the remaining waste is called automotive shredder residue (ASR), or car fluff. In Europe, this is mainly landfilled because it is extremely heterogeneous and often polluted with car fluids. Despite technical difficulties, in the coming years it will be necessary to recover materials from car fluff in order to meet the ELV Directive requirement. This study deals with ASR pretreatment and pyrolysis, and aims to determine whether the ELV material recycling target may be achieved by car fluff mechanical separation followed by pyrolysis with a bench scale reactor. Results show that flotation followed by pyrolysis of the light, organic fraction may be a suitable ASR recycling technique if the oil can be further refined and used as a chemical. Moreover, metals are liberated during thermal cracking and can be easily separated from the pyrolysis char, amounting to roughly 5% in mass. Lastly, pyrolysis can be a good starting point from a "waste-to-chemicals" perspective, but further research should be done with a focus on oil and gas refining, in order both to make products suitable for the chemical industry and to render the whole recycling process economically feasible. Copyright © 2011 Elsevier Ltd. All rights reserved.

Aromatic chemicals by iron-catalyzed hydrotreatment of lignin pyrolysis vapor.

PubMed

Olcese, Roberto Nicolas; Lardier, George; Bettahar, Mohammed; Ghanbaja, Jaafar; Fontana, Sébastien; Carré, Vincent; Aubriet, Frédéric; Petitjean, Dominique; Dufour, Anthony

2013-08-01

Lignin is a potential renewable material for the production of bio-sourced aromatic chemicals. We present the first hydrotreatment of lignin pyrolysis vapors, before any condensation, using inexpensive and sustainable iron-silica (Fe/SiO2 ) and iron-activated carbon (Fe/AC) catalysts. Lignin pyrolysis was conducted in a tubular reactor and vapors were injected in a fixed bed of catalysts (673 K, 1 bar) with stacks to investigate the profile of coke deposit. More than 170 GC-analyzable compounds were identified by GCxGC (heart cutting)/flame ionization detector mass spectrometry. Lignin oligomers were analyzed by very high resolution mass spectrometry, called the "petroleomic" method. They are trapped by the catalytic fixed bed and, in particular, by the AC. The catalysts showed a good selectivity for the hydrodeoxygenation of real lignin vapors to benzene, toluene, xylenes, phenol, cresols, and alkyl phenols. The spent catalysts were characterized by temperature-programmed oxidation, transmission electron microscopy (TEM), and N2 sorption. Micropores in the Fe/AC catalyst are completely plugged by coke deposits, whereas the mesoporous structure of Fe/SiO2 is unaffected. TEM images reveal two different types of coke deposit: 1) catalytic coke deposited in the vicinity of iron particles and 2) thermal coke (carbonaceous particles ≈1 μm in diameter) formed from the gas-phase growth of lignin oligomers. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR 721.10579 - Carbon black derived from the pyrolysis of rubber tire shreds (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pyrolysis of rubber tire shreds (generic). 721.10579 Section 721.10579 Protection of Environment... pyrolysis of rubber tire shreds (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as carbon black derived from the pyrolysis of...

Structural analysis of pyrolytic lignins isolated from switchgrass fast pyrolysis oil

USDA-ARS?s Scientific Manuscript database

Structural characterization of lignin extracted from the bio-oil produced by fast pyrolysis of switchgrass (Panicum virgatum) is reported. This new information is important to understanding the utility of lignin as a chemical feedstock in a pyrolysis based biorefinery. Pyrolysis induces a variety of...

Characterization and pyrolysis of Chlorella vulgaris and Arthrospira platensis: potential of bio-oil and chemical production by Py-GC/MS analysis.

PubMed

Almeida, Hanna N; Calixto, Guilherme Q; Chagas, Bruna M E; Melo, Dulce M A; Resende, Fabio M; Melo, Marcus A F; Braga, Renata Martins

2017-06-01

Biofuels have been seen as potential sources to meet future energy demand as a renewable and sustainable energy source. Despite the fact that the production technology of first-generation biofuels is consolidated, these biofuels are produced from foods crops such as grains, sugar cane, and vegetable oils competing with food for crop use and agricultural land. In recent years, it was found that microalgae have the potential to provide a viable alternative to fossil fuels as source of biofuels without compromising food supplies or arable land. On this scenario, this paper aims to demonstrate the energetic potential to produce bio-oil and chemicals from microalgae Chlorella vulgaris and Arthrospira platensis. The potential of these biomasses was evaluated in terms of physical-chemical characterization, thermogravimetric analysis, and analytical pyrolysis interfaced with gas chromatograph (Py-GC/MS). The results show that C. vulgaris and A. platensis are biomasses with a high heating value (24.60 and 22.43 MJ/kg) and low ash content, showing a high percentage of volatile matter (72.49 and 79.42%). These characteristics confirm their energetic potential for conversion process through pyrolysis, whereby some important aromatic compounds such as toluene, styrene, and phenol were identified as pyrolysis products, which could turn these microalgae a potential for biofuels and bioproduct production through the pyrolysis.

57Fe CEMS study on dilute metal ions codoped SnO2 thin films prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

Nomura, Kiyoshi; Koike, Yuya; Nakanishi, Akio

2017-11-01

Dilute Mn-Fe, Co-Fe and V-Fe codoped tin oxide films prepared by spray pyrolysis were characterized by 57Fe conversion electron Mössbauer spectrometry (CEMS) at room temperature (RT) and at 20 K. Two kinds of paramagnetic Fe3+ species were detected at RT; one doublet 1 (D1) with IS = 0.36-0.37 mm/s, QS = 0.69-0.75 mm/s and LW = 0.32-0.40 mm/s, and another doublet 2 (D2) with IS = 0.31-0.35 mm/s QS = 1.16-1.25 mm/s and LW = 0.46-0.52 mm/s. CEMS at 20 K provided more distinguished doublets than at RT. It is found that especially D2 with relatively small IS and large QS values are influenced by other metal ions codoped in SnO2 matrix, whereas D1 with relatively large IS and small QS has the parameters close to the models of Fe-VO1 and Fe-2VO1-Fe models (Nomura et al. Phys. Rev. B 75, 184411 2007; Mudarra Navarro et al. J. Phys. Chem. C 119, 5596-5603 2015).

Effect of chemical pretreatment on pyrolysis of non-metallic fraction recycled from waste printed circuit boards.

PubMed

Shen, Yafei

2018-06-01

The non-metallic fraction from waste printed circuit boards (NMF-WPCB) generally consists of plastics with high content of Br, glass fibers and metals (e.g. Cu), which are normally difficult to dispose. This work aims to study the chemical pretreatments by using alkalis, acids and alkali-earth-metal salts on pyrolysis of NMF-WPCB. Char (60-79%) and volatile matter (21-40%) can be produced via the pyrolysis process. In particular, the ash content can reach up to 42-56%, which was attributed to the high content of glass fibers and other minerals. Copper (Cu, 2.5%), calcium (Ca, 28.7%), and aluminum (Al, 6.9%) were the main metal constituents. Meanwhile, silicon (Si, 28.3%) and bromine (Br, 26.4%) were the predominant non-metallic constituents. The heavy metals such as Cu were significantly reduced by 92.4% with the acid (i.e. HCl) pretreatment. It has been proved that the organic Br in the plastics (e.g. BFR) can be transformed into HBr via the pyrolysis process at relatively high temperature. It was noteworthy that the alkali pretreatment was more benefit for the Br fixation in the solid char. Particularly, the Br fixation efficiency can reach up to 53.6% by the sodium hydroxide (NaOH) pretreatment with the pyrolysis process. The formed HBr can react with NaOH to generate NaBr. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemistry of decomposition of freshwater wetland sedimentary organic material during ramped pyrolysis

NASA Astrophysics Data System (ADS)

Williams, E. K.; Rosenheim, B. E.

2011-12-01

Ramped pyrolysis methodology, such as that used in the programmed-temperature pyrolysis/combustion system (PTP/CS), improves radiocarbon analysis of geologic materials devoid of authigenic carbonate compounds and with low concentrations of extractable authochthonous organic molecules. The approach has improved sediment chronology in organic-rich sediments proximal to Antarctic ice shelves (Rosenheim et al., 2008) and constrained the carbon sequestration potential of suspended sediments in the lower Mississippi River (Roe et al., in review). Although ramped pyrolysis allows for separation of sedimentary organic material based upon relative reactivity, chemical information (i.e. chemical composition of pyrolysis products) is lost during the in-line combustion of pyrolysis products. A first order approximation of ramped pyrolysis/combustion system CO2 evolution, employing a simple Gaussian decomposition routine, has been useful (Rosenheim et al., 2008), but improvements may be possible. First, without prior compound-specific extractions, the molecular composition of sedimentary organic matter is unknown and/or unidentifiable. Second, even if determined as constituents of sedimentary organic material, many organic compounds have unknown or variable decomposition temperatures. Third, mixtures of organic compounds may result in significant chemistry within the pyrolysis reactor, prior to introduction of oxygen along the flow path. Gaussian decomposition of the reaction rate may be too simple to fully explain the combination of these factors. To relate both the radiocarbon age over different temperature intervals and the pyrolysis reaction thermograph (temperature (°C) vs. CO2 evolved (μmol)) obtained from PTP/CS to chemical composition of sedimentary organic material, we present a modeling framework developed based upon the ramped pyrolysis decomposition of simple mixtures of organic compounds (i.e. cellulose, lignin, plant fatty acids, etc.) often found in sedimentary

Chemical pleurodesis using mistletoe extracts via spray catheter during medical thoracoscopy for management of malignant pleural effusion.

PubMed

Eom, Jung Seop; Kim, Tae Hwa; Lee, Geewon; Ahn, Hyo Yeong; Mok, Jeong Ha; Lee, Min Ki

2017-05-01

We present three cases of successful chemical pleurodesis with a liquid solution of mistletoe extract using a spray catheter during medical thoracoscopy. The medical thoracoscopy was performed in all presented cases to remove pleural effusion and conduct chemical pleurodesis to manage symptomatic malignant pleural effusion. A spray catheter was used to instil the mistletoe extract evenly into the pleural cavity, and there were no pleurodesis-related complications. Respiratory symptoms caused by pleural effusion improved after pleurodesis, and successful pleurodesis was maintained for more than 3 months after medical thoracoscopy in all three patients.

The slow and fast pyrolysis of cherry seed.

PubMed

Duman, Gozde; Okutucu, Cagdas; Ucar, Suat; Stahl, Ralph; Yanik, Jale

2011-01-01

The slow and fast pyrolysis of cherry seeds (CWS) and cherry seeds shells (CSS) was studied in fixed-bed and fluidized bed reactors at different pyrolysis temperatures. The effects of reactor type and temperature on the yields and composition of products were investigated. In the case of fast pyrolysis, the maximum bio-oil yield was found to be about 44 wt% at pyrolysis temperature of 500 °C for both CWS and CSS, whereas the bio yields were of 21 and 15 wt% obtained at 500 °C from slow pyrolysis of CWS and CSS, respectively. Both temperature and reactor type affected the composition of bio-oils. The results showed that bio-oils obtained from slow pyrolysis of CWS and CSS can be used as a fuel for combustion systems in industry and the bio-oil produced from fast pyrolysis can be evaluated as a chemical feedstock. Copyright © 2010 Elsevier Ltd. All rights reserved.

Pyrolysis of waste tyres: a review.

PubMed

Williams, Paul T

2013-08-01

Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H(2), C(1)-C(4) hydrocarbons, CO(2), CO and H(2)S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simulating Biomass Fast Pyrolysis at the Single Particle Scale

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

Ciesielski, Peter; Wiggins, Gavin; Daw, C Stuart

2017-07-01

Simulating fast pyrolysis at the scale of single particles allows for the investigation of the impacts of feedstock-specific parameters such as particle size, shape, and species of origin. For this reason particle-scale modeling has emerged as an important tool for understanding how variations in feedstock properties affect the outcomes of pyrolysis processes. The origins of feedstock properties are largely dictated by the composition and hierarchical structure of biomass, from the microstructural porosity to the external morphology of milled particles. These properties may be accounted for in simulations of fast pyrolysis by several different computational approaches depending on the level ofmore » structural and chemical complexity included in the model. The predictive utility of particle-scale simulations of fast pyrolysis can still be enhanced substantially by advancements in several areas. Most notably, considerable progress would be facilitated by the development of pyrolysis kinetic schemes that are decoupled from transport phenomena, predict product evolution from whole-biomass with increased chemical speciation, and are still tractable with present-day computational resources.« less

Catalytic pyrolysis-gc/ms of spirulina: evaluation of a highly proteinaceous biomass source for production of fuels and chemicals

USDA-ARS?s Scientific Manuscript database

Pyrolysis of microalgae offers a pathway towards the production of compounds derived from the thermal decomposition of triglycerides, proteins as well as lignocelluloses and their combinations thereof. When catalytically induced, this could lead to the production of fuels and chemicals including aro...

Ultrasonic spray pyrolysis synthesis of reduced graphene oxide/anatase TiO2 composite and its application in the photocatalytic degradation of methylene blue in water.

PubMed

Park, Jeong-Ann; Yang, Boram; Lee, Joongki; Kim, In Gyeom; Kim, Jae-Hyun; Choi, Jae-Woo; Park, Hee-Deung; Nah, In Wook; Lee, Sang-Hyup

2018-01-01

Reduced graphene oxide (RGO)/anatase TiO 2 composite was prepared using a simple one-step technique-ultrasonic spray pyrolysis-in order to inhibit the aggregation of TiO 2 nanoparticles and to improve the photocatalytic performance for degradation of methylene blue (MB). Different proportions (0-5 wt%) of RGO/TiO 2 composites were characterized by scanning electronic microscopy (SEM), dispersive X-ray spectrometry (EDS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), Raman spectroscopy, UV-vis spectroscopy, and electrochemical impedance spectroscopy (EIS) to verify mechanism. From these analysis, TiO 2 nanoparticles are distributed uniformly on the RGO sheets with crumpled shape during ultrasonic spray pyrolysis and surface area is increasing by increasing portion of RGO. Band gap of RGO 5 /TiO 2 (5 wt% of RGO) composite is 2.72 eV and band gap was reduced by increasing portion of RGO in RGO/TiO 2 composites. The RGO 5 /TiO 2 composite was superior to other lower content of RGO/TiO 2 composites with a rapid transport of charge carriers and an effective charge separation. The highest removal efficiency of MB was obtained at the RGO 5 /TiO 2 composite under UVC irradiation, which coincided with the EIS, and the optimal dose of the composite was determined to be 0.5 g/L. The RGO 5 /TiO 2 composite improve the photocatalytic degradation rate of MB over the TiO 2 due to a retardation of electron-hole recombination. The MB adsorption capacity and photocatalytic degradation efficiency were greatly affected by pH changes and increased with increasing pH due to electrostatic interactions and generation of more hydroxyl radicals. The reusability of RGO 5 /TiO 2 composite was examined during 3 cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Pr3+doping on key properties of CdO thin films deposited by spray pyrolysis using perfume atomizer

NASA Astrophysics Data System (ADS)

Ravikumar, M.; Chandramohan, R.; Kumar, K. Deva Arun; Valanarasu, S.; Kathalingam, A.; Ganesh, V.; Shkir, Mohd.; AlFaify, S.; Algarni, H.

2018-07-01

High quality Cadmium oxide thin films doped with Praseodymium (Pr) were prepared using perfume atomizer based spray pyrolysis technique at substrate temperature near 350 °C. Structural analysis of films was examined by XRD and confirmed that the films are cubic in structure. All un-doped and doped films were good crystalline in nature with smooth and flat surface without significant modifications owed to doping. Optical transmittances of doped films was decrease in the visible and IR range with increasing Pr doping concentration. Band gap widened from 2.42 to 2.20 eV when doped with Pr from 0 to 5 at. %. In addition, the photoluminescence property of the films was also observed. Further, the electrical studies were performed on pure and doped samples Viz., the electrical resistivity, carrier concentration (ρ) and Hall mobility (μ). It confirmed that the deposited films has good structural environments in terms of grain size, absolute stress correspond and low resistivity. Current-voltage measurements on the nanostructured Al/Pr-nCdO/p-Si/Al device showed a non-linear electric characteristics indicating diode like behavior.

Effect of Sn doping on the structural, optical and electrical properties of TiO2 films prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

Arunachalam, A.; Dhanapandian, S.; Manoharan, C.

2016-02-01

In this work, highly oriented pure and Tin-doped Titanium dioxide (Sn-doped TiO2) with porous nature photoelectrodes were deposited on ITO glass plates using spray pyrolysis technique. The XRD pattern revealed the formation of anatase TiO2 with the maximum intensity of (101) plane while doping 6 at% of Sn. The morphological studies depicted the porous nature with the uniform arrangement of small-sized grains. The presence of tin confirmed with the EDX spectra. The size of particles of 13 nm was observed from High Resolution Transmission Electron Microscopy (HR-TEM) analysis. The average transmittance was about 85% for the doped photoelectrode and was observed for the photoelectrode deposited with 6 at% of tin, with decreased energy band gap. The PL study showed the emission peak at 391 nm. The maximum carrier concentration and Hall mobility was observed for the photoelectrode deposited with 6 at% of tin. With these studies, the DSSCs were prepared separately with the dye extracted from Hibiscus Rosasinesis and Hibiscus Surttasinesis and their efficiency was maximum for the DSSC prepared with 6 at% of tin.

The Spray-Rite Kit. A Guide to Using Chemicals on the Farm.

ERIC Educational Resources Information Center

Stevens, Nick; And Others

This resource is designed to assist rural adult literacy students. It deals with chemicals on the farm and aims to help students understand the technical language, concepts, and operations associated with spraying safely and effectively. The kit proceeds step-by-step from purchase to disposal. Material is divided into two sections. Section 1…

Pyrolysis of triglyceride materials for the production of renewable fuels and chemicals.

PubMed

Maher, K D; Bressler, D C

2007-09-01

Conversion of vegetable oils and animal fats composed predominantly of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to collect and review literature on the thermo-chemical conversion of triglyceride based materials. The literature was divided and discussed as (1) direct thermal cracking and (2) combination of thermal and catalytic cracking. Typically, four main catalyst types are used including transition metal catalysts, molecular sieve type catalysts, activated alumina, and sodium carbonate. Reaction products are heavily dependant on the catalyst type and reaction conditions and can range from diesel like fractions to gasoline like fractions. Research in this area is not as advanced as bio-oil and bio-diesel research and there is opportunity for further study in the areas of reaction optimization, detailed characterization of products and properties, and scale-up.

Quantitative Insights into the Fast Pyrolysis of Extracted Cellulose, Hemicelluloses, and Lignin

PubMed Central

Windt, Michael; Ziegler, Bernhard; Appelt, Jörn; Saake, Bodo; Meier, Dietrich; Bridgwater, Anthony

2017-01-01

Abstract The transformation of lignocellulosic biomass into bio‐based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached a commercial level, produces a high yield of an organic‐rich liquid stream. Despite recent efforts to elucidate the degradation paths of biomass during pyrolysis, the selectivity and recovery rates of bio‐compounds remain low. In an attempt to clarify the general degradation scheme of biomass fast pyrolysis and provide a quantitative insight, the use of fast pyrolysis microreactors is combined with spectroscopic techniques (i.e., mass spectrometry and NMR spectroscopy) and mixtures of unlabeled and 13C‐enriched materials. The first stage of the work aimed to select the type of reactor to use to ensure control of the pyrolysis regime. A comparison of the chemical fragmentation patterns of “primary” fast pyrolysis volatiles detected by using GC‐MS between two small‐scale microreactors showed the inevitable occurrence of secondary reactions. In the second stage, liquid fractions that are also made of primary fast pyrolysis condensates were analyzed by using quantitative liquid‐state 13C NMR spectroscopy to provide a quantitative distribution of functional groups. The compilation of these results into a map that displays the distribution of functional groups according to the individual and main constituents of biomass (i.e., hemicelluloses, cellulose and lignin) confirmed the origin of individual chemicals within the fast pyrolysis liquids. PMID:28644517

Quantitative Insights into the Fast Pyrolysis of Extracted Cellulose, Hemicelluloses, and Lignin.

PubMed

Carrier, Marion; Windt, Michael; Ziegler, Bernhard; Appelt, Jörn; Saake, Bodo; Meier, Dietrich; Bridgwater, Anthony

2017-08-24

The transformation of lignocellulosic biomass into bio-based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached a commercial level, produces a high yield of an organic-rich liquid stream. Despite recent efforts to elucidate the degradation paths of biomass during pyrolysis, the selectivity and recovery rates of bio-compounds remain low. In an attempt to clarify the general degradation scheme of biomass fast pyrolysis and provide a quantitative insight, the use of fast pyrolysis microreactors is combined with spectroscopic techniques (i.e., mass spectrometry and NMR spectroscopy) and mixtures of unlabeled and 13 C-enriched materials. The first stage of the work aimed to select the type of reactor to use to ensure control of the pyrolysis regime. A comparison of the chemical fragmentation patterns of "primary" fast pyrolysis volatiles detected by using GC-MS between two small-scale microreactors showed the inevitable occurrence of secondary reactions. In the second stage, liquid fractions that are also made of primary fast pyrolysis condensates were analyzed by using quantitative liquid-state 13 C NMR spectroscopy to provide a quantitative distribution of functional groups. The compilation of these results into a map that displays the distribution of functional groups according to the individual and main constituents of biomass (i.e., hemicelluloses, cellulose and lignin) confirmed the origin of individual chemicals within the fast pyrolysis liquids. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Fractional condensation of pyrolysis vapors produced from Nordic feedstocks in cyclone pyrolysis

DOE PAGES

Johansson, Ann-Christine; Lisa, Kristiina; Sandström, Linda; ...

2016-12-06

Pyrolysis oil is a complex mixture of different chemical compounds with a wide range of molecular weights and boiling points. Due to its complexity, an efficient fractionation of the oil may be a more promising approach of producing liquid fuels and chemicals than treating the whole oil. In this work a sampling system based on fractional condensation was attached to a cyclone pyrolysis pilot plant to enable separation of the produced pyrolysis vapors into five oil fractions. The sampling system was composed of cyclonic condensers and coalescing filters arranged in series. Our objective was to characterize the oil fractions producedmore » from three different Nordic feedstocks and suggest possible applications. The oil fractions were thoroughly characterized using several analytical techniques including water content; elemental composition; heating value, and chemical compound group analysis using solvent fractionation, quantitative 13C NMR and 1H NMR and GC x GC - TOFMS. The results show that the oil fractions significantly differ from each other both in chemical and physical properties. The first fractions and the fraction composed of aerosols were highly viscous and contained larger energy-rich compounds of mainly lignin-derived material. The middle fraction contained medium-size compounds with relatively high concentration of water, sugars, alcohols, hydrocarbonyls and acids and finally the last fraction contained smaller molecules such as water, aldehydes, ketones and acids. But, the properties of the respective fractions seem independent on the studied feedstock types, i.e. the respective fractions produced from different feedstock are rather similar. Furthermore, this promotes the possibility to vary the feedstock depending on availability while retaining the oil properties. Possible applications of the five fractions vary from oil for combustion and extraction of the pyrolytic lignin in the early fractions to extraction of sugars from the early and middle

Fractional condensation of pyrolysis vapors produced from Nordic feedstocks in cyclone pyrolysis

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

Johansson, Ann-Christine; Lisa, Kristiina; Sandström, Linda

Pyrolysis oil is a complex mixture of different chemical compounds with a wide range of molecular weights and boiling points. Due to its complexity, an efficient fractionation of the oil may be a more promising approach of producing liquid fuels and chemicals than treating the whole oil. In this work a sampling system based on fractional condensation was attached to a cyclone pyrolysis pilot plant to enable separation of the produced pyrolysis vapors into five oil fractions. The sampling system was composed of cyclonic condensers and coalescing filters arranged in series. Our objective was to characterize the oil fractions producedmore » from three different Nordic feedstocks and suggest possible applications. The oil fractions were thoroughly characterized using several analytical techniques including water content; elemental composition; heating value, and chemical compound group analysis using solvent fractionation, quantitative 13C NMR and 1H NMR and GC x GC - TOFMS. The results show that the oil fractions significantly differ from each other both in chemical and physical properties. The first fractions and the fraction composed of aerosols were highly viscous and contained larger energy-rich compounds of mainly lignin-derived material. The middle fraction contained medium-size compounds with relatively high concentration of water, sugars, alcohols, hydrocarbonyls and acids and finally the last fraction contained smaller molecules such as water, aldehydes, ketones and acids. But, the properties of the respective fractions seem independent on the studied feedstock types, i.e. the respective fractions produced from different feedstock are rather similar. Furthermore, this promotes the possibility to vary the feedstock depending on availability while retaining the oil properties. Possible applications of the five fractions vary from oil for combustion and extraction of the pyrolytic lignin in the early fractions to extraction of sugars from the early and middle

Charcoal from the pyrolysis of rapeseed plant straw-stalk

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

Karaosmanoglu, F.; Tetik, E.

1999-07-01

Charcoal is an important product of pyrolysis of biomass sources. Charcoal can be used for domestic, agricultural, metallurgical, and chemical purposes. In this study different characteristics of charcoal, one of the rape seed plant straw-stalk pyrolysis product, was researched and presented as candidates.

Preparation, properties, and bonding utilization of pyrolysis bio-oil

USDA-ARS?s Scientific Manuscript database

The rapid increase in energy consumption, limited fossil fuel resource, and environmental concerns have stimulated the research need for biomass-derived fuels and chemicals. Pyrolysis is a thermal degradation process of biomass in the absence of oxygen. The liquid product from pyrolysis is known as ...

Fabrication of Semiconducting Methylammonium Lead Halide Perovskite Particles by Spray Technology

NASA Astrophysics Data System (ADS)

Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

2018-01-01

In this "nano idea" paper, three concepts for the preparation of methylammonium lead halide perovskite particles are proposed, discussed, and tested. The first idea is based on the wet chemistry preparation of the perovskite particles, through the addition of the perovskite precursor solution to an anti-solvent to facilitate the precipitation of the perovskite particles in the solution. The second idea is based on the milling of a blend of the perovskite precursors in the dry form, in order to allow for the conversion of the precursors to the perovskite particles. The third idea is based on the atomization of the perovskite solution by a spray nozzle, introducing the spray droplets into a hot wall reactor, so as to prepare perovskite particles, using the droplet-to-particle spray approach (spray pyrolysis). Preliminary results show that the spray technology is the most successful method for the preparation of impurity-free perovskite particles and perovskite paste to deposit perovskite thin films. As a proof of concept, a perovskite solar cell with the paste prepared by the sprayed perovskite powder was successfully fabricated.

Fabrication of Semiconducting Methylammonium Lead Halide Perovskite Particles by Spray Technology.

PubMed

Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

2018-01-10

In this "nano idea" paper, three concepts for the preparation of methylammonium lead halide perovskite particles are proposed, discussed, and tested. The first idea is based on the wet chemistry preparation of the perovskite particles, through the addition of the perovskite precursor solution to an anti-solvent to facilitate the precipitation of the perovskite particles in the solution. The second idea is based on the milling of a blend of the perovskite precursors in the dry form, in order to allow for the conversion of the precursors to the perovskite particles. The third idea is based on the atomization of the perovskite solution by a spray nozzle, introducing the spray droplets into a hot wall reactor, so as to prepare perovskite particles, using the droplet-to-particle spray approach (spray pyrolysis). Preliminary results show that the spray technology is the most successful method for the preparation of impurity-free perovskite particles and perovskite paste to deposit perovskite thin films. As a proof of concept, a perovskite solar cell with the paste prepared by the sprayed perovskite powder was successfully fabricated.

ENGINEERING BULLETIN: PYROLYSIS TREATMENT

EPA Science Inventory

Pyrolysis is formally defined as chemical decomposition induced in organic materials by heat in the absence of oxygen. In practice, it is not possible to achieve a completely oxygen-free atmosphere; actual pyrolytic systems are operated with less than stoichiometric quantities of...

Effect of S-doping on structural, optical and electrochemical properties of vanadium oxide thin films prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

2013-12-01

In this research, S-doped vanadium oxide thin films, with doping levels from 0 to 40 at.%, are prepared by spray pyrolysis technique on glass substrates. For electrochemical measurements, the films were deposited on florin-tin oxide coated glass substrates. The effect of S-doping on structural, electrical, optical and electrochemical properties of vanadium oxide thin films was studied. The x-ray diffractometer analysis indicated that most of the samples have cubic β-V2O5 phase structure with preferred orientation along [200]. With increase in the doping levels, the structure of the samples tends to be amorphous. The scanning electron microscopy images show that the structure of the samples is nanobelt-shaped and the width of the nanobelts decreases from nearly 100 to 40 nm with increase in the S concentration. With increase in the S-doping level, the sheet resistance and the optical band gap increase from 940 to 4015 kΩ/square and 2.41 to 2.7 eV, respectively. The cyclic voltammogram results obtained for different samples show that the undoped sample is expanded and the sample prepared at 20 at.% S-doping level has sharper anodic and cathodic peaks.

The effect of solution concentration on the physical and electrochemical properties of vanadium oxide films deposited by spray pyrolysis

NASA Astrophysics Data System (ADS)

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M. M.

2013-10-01

Vanadium oxide thin films were prepared on glass substrates by using the spray pyrolysis technique. The effect of solution concentration (0.1 M, 0.2 M and 0.3 M) on the nanostructural, electrical, optical, and electrochromic properties of deposited films were investigated using X-ray diffraction, scanning electron microscopy, UV—vis spectroscopy, and cyclic volta-metrics. The X-ray diffraction shows that only the sample at 0.1 M has a single β-V2O5 phase and the others have mixed phases of vanadium oxide. The lowest sheet resistance was obtained for the samples prepared at 0.3 M solution. It was also found that the optical transparency of the samples changes from 70% to 35% and the optical band gap of the samples was in the range of 2.20 to 2.41 eV, depending on the morality of solution. The cycle voltammogram shows that the sample prepared at 0.3 M has one-step electerochoromic but the other samples have two-step electerochoromic. The results show a correlation between the cycle voltammogram and the physical properties of the films.

Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

NASA Astrophysics Data System (ADS)

Novruzov, V. D.; Keskenler, E. F.; Tomakin, M.; Kahraman, S.; Gorur, O.

2013-09-01

Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu2S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

Behavior of chlorine during coal pyrolysis

USGS Publications Warehouse

Shao, D.; Hutchinson, E.J.; Cao, H.; Pan, W.-P.; Chou, C.-L.

1994-01-01

The behavior of chlorine in Illinois coals during pyrolysis was evaluated by combined thermo-gravimetry-Fourier transform infrared spectroscopy-ion chromatography (TG-FTIR-IC) techniques. It was found that more than 90% of chlorine in Illinois coals (IBC-103, 105, 106, and 109) was liberated as HCl gas during pyrolysis from 300 to 600??C, with the rate reaching a maximum at 440 ??C. Similarity of the HCl and NH3 release profiles during pyrolysis of IBC-109 supports the hypothesis that the chlorine in coal may be associated with nitrogen and the chlorine is probably bonded to the basic nitrogen sites on the inner walls of coal micropores. ?? 1994 American Chemical Society.

A spray flamelet/progress variable approach combined with a transported joint PDF model for turbulent spray flames

NASA Astrophysics Data System (ADS)

Hu, Yong; Olguin, Hernan; Gutheil, Eva

2017-05-01

A spray flamelet/progress variable approach is developed for use in spray combustion with partly pre-vaporised liquid fuel, where a laminar spray flamelet library accounts for evaporation within the laminar flame structures. For this purpose, the standard spray flamelet formulation for pure evaporating liquid fuel and oxidiser is extended by a chemical reaction progress variable in both the turbulent spray flame model and the laminar spray flame structures, in order to account for the effect of pre-vaporised liquid fuel for instance through use of a pilot flame. This new approach is combined with a transported joint probability density function (PDF) method for the simulation of a turbulent piloted ethanol/air spray flame, and the extension requires the formulation of a joint three-variate PDF depending on the gas phase mixture fraction, the chemical reaction progress variable, and gas enthalpy. The molecular mixing is modelled with the extended interaction-by-exchange-with-the-mean (IEM) model, where source terms account for spray evaporation and heat exchange due to evaporation as well as the chemical reaction rate for the chemical reaction progress variable. This is the first formulation using a spray flamelet model considering both evaporation and partly pre-vaporised liquid fuel within the laminar spray flamelets. Results with this new formulation show good agreement with the experimental data provided by A.R. Masri, Sydney, Australia. The analysis of the Lagrangian statistics of the gas temperature and the OH mass fraction indicates that partially premixed combustion prevails near the nozzle exit of the spray, whereas further downstream, the non-premixed flame is promoted towards the inner rich-side of the spray jet since the pilot flame heats up the premixed inner spray zone. In summary, the simulation with the new formulation considering the reaction progress variable shows good performance, greatly improving the standard formulation, and it provides new

Effects of feedstock characteristics on microwave-assisted pyrolysis - A review.

PubMed

Zhang, Yaning; Chen, Paul; Liu, Shiyu; Peng, Peng; Min, Min; Cheng, Yanling; Anderson, Erik; Zhou, Nan; Fan, Liangliang; Liu, Chenghui; Chen, Guo; Liu, Yuhuan; Lei, Hanwu; Li, Bingxi; Ruan, Roger

2017-04-01

Microwave-assisted pyrolysis is an important approach to obtain bio-oil from biomass. Similar to conventional electrical heating pyrolysis, microwave-assisted pyrolysis is significantly affected by feedstock characteristics. However, microwave heating has its unique features which strongly depend on the physical and chemical properties of biomass feedstock. In this review, the relationships among heating, bio-oil yield, and feedstock particle size, moisture content, inorganics, and organics in microwave-assisted pyrolysis are discussed and compared with those in conventional electrical heating pyrolysis. The quantitative analysis of data reported in the literature showed a strong contrast between the conventional processes and microwave based processes. Microwave-assisted pyrolysis is a relatively new process with limited research compared with conventional electrical heating pyrolysis. The lack of understanding of some observed results warrant more and in-depth fundamental research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Mo-doping concentration on the physical behaviour of sprayed ZnO layers

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

Reddy, T. Sreenivasulu; Reddy, M. Vasudeva; Reddy, K. T. Ramakrishna, E-mail: ktrkreddy@gmail.com

2015-06-24

Mo-doped zinc oxide layers (MZO) have been prepared on cleaned glass substrates by chemical spray pyrolysis technique by varying Mo-doping concentration in the range, 0 – 5 at. %. The X-ray diffraction studies revealed that all the as prepared layers were polycrystalline in nature and exhibited wurtzite structure. The layers prepared with lower Mo-doping concentration (<2 at. %) were preferably oriented along the (100) plane, whereas in the case of higher Mo-doping concentration (>2 at. %), the films showed the (002) plane as the dominant peak. The optical analysis indicated that all the layers had an average optical transmittance ofmore » 80% in the visible region and the evaluated band gap varied in the range, 3.28 - 3.50 eV.« less

Method to synthesize and produce thin films by spray pyrolysis

DOEpatents

Turcotte, Richard L.

1982-07-06

Forming a film by spraying onto a heated substrate an atomized solution containing the appropriate salt of a constituent element of the film and a reducing agent at a concentration greater than 1 M and greater than 10 times the stoichiometric amount of reducing agent.

Method for Hot Real-Time Analysis of Pyrolysis Vapors at Pilot Scale

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

Pomeroy, Marc D

Pyrolysis oils contain more than 400 compounds, up to 60% of which do not re-volatilize for subsequent chemical analysis. Vapor chemical composition is also complicated as additional condensation reactions occur during quenching and collection of the product. Due to the complexity of the pyrolysis oil, and a desire to catalytically upgrade the vapor composition before condensation, online real-time analytical techniques such as Molecular Beam Mass Spectrometry (MBMS) are of great use. However, in order to properly sample hot pyrolysis vapors at the pilot scale, many challenges must be overcome.

Vertically aligned carbon nanotubes from natural precursors by spray pyrolysis method and their field electron emission properties

NASA Astrophysics Data System (ADS)

Ghosh, Pradip; Soga, T.; Tanemura, M.; Zamri, M.; Jimbo, T.; Katoh, R.; Sumiyama, K.

2009-01-01

Vertically aligned carbon nanotubes have been synthesized from botanical hydrocarbons: Turpentine oil and Eucalyptus oil on Si(100) substrate using Fe catalyst by simple spray pyrolysis method at 700°C and at atmospheric pressure. The as-grown carbon nanotubes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and Raman spectroscopy. It was observed that nanotubes grown from turpentine oil have better degree of graphitization and field emission performance than eucalyptus oil grown carbon nanotubes. The turpentine oil and eucalyptus oil grown carbon nanotubes indicated that the turn-on field of about 1.7 and 1.93 V/μm, respectively, at 10 μA/cm2. The threshold field was observed to be about 2.13 and 2.9 V/μm at 1 mA/cm2 of nanotubes grown from turpentine oil and eucalyptus oil respectively. Moreover, turpentine oil grown carbon nanotubes show higher current density in relative to eucalyptus oil grown carbon nanotubes. The maximum current density of 15.3 mA/cm2 was obtained for ˜3 V/μm corresponding to the nanotubes grown from turpentine oil. The improved field emission performance was attributed to the enhanced crystallinity, fewer defects, and greater length of turpentine oil grown carbon nanotubes.

High-throughput screening of nanoparticle catalysts made by flame spray pyrolysis as hydrocarbon/NO oxidation catalysts.

PubMed

Weidenhof, B; Reiser, M; Stöwe, K; Maier, W F; Kim, M; Azurdia, J; Gulari, E; Seker, E; Barks, A; Laine, R M

2009-07-08

We describe here the use of liquid-feed flame spray pyrolysis (LF-FSP) to produce high surface area, nonporous, mixed-metal oxide nanopowders that were subsequently subjected to high-throughput screening to assess a set of materials for deNO(x) catalysis and hydrocarbon combustion. We were able to easily screen some 40 LF-FSP produced materials. LF-FSP produces nanopowders that very often consist of kinetic rather than thermodynamic phases. Such materials are difficult to access or are completely inaccessible via traditional catalyst preparation methods. Indeed, our studies identified a set of Ce(1-x)Zr(x)O(2) and Al(2)O(3)-Ce(1-x)Zr(x)O(2) nanopowders that offer surprisingly good activities for both NO(x) reduction and propane/propene oxidation both in high-throughput screening and in continuous flow catalytic studies. All of these catalysts offer activities comparable to traditional Pt/Al(2)O(3) catalysts but without Pt. Thus, although Pt-free, they are quite active for several extremely important emission control reactions, especially considering that these are only first generation materials. Indeed, efforts to dope the active catalysts with Pt actually led to lower catalytic activities. Thus the potential exists to completely change the materials used in emission control devices, especially for high-temperature reactions as these materials have already been exposed to 1500 degrees C; however, much research must be done before this potential is verified.

Pyrolysis temperature affects phosphorus transformation in biochar: Chemical fractionation and (31)P NMR analysis.

PubMed

Xu, Gang; Zhang, You; Shao, Hongbo; Sun, Junna

2016-11-01

Phosphorus (P) recycling or reuse by pyrolyzing crop residue has recently elicited increased research interest. However, the effects of feedstock and pyrolysis conditions on P species have not been fully understood. Such knowledge is important in identifying the agronomic and environmental uses of biochar. Residues of three main Chinese agricultural crops and the biochars (produced at 300°C-600°C) derived from these crops were used to determine P transformations during pyrolysis. Hedley sequential fractionation and (31)P NMR analyses were used in the investigation. Our results showed that P transformation in biochar was significantly affected by pyrolysis temperature regardless of feedstock (Wheat straw, maize straw and peanut husk). Pyrolysis treatment transformed water soluble P into a labile (NaHCO3-Pi) or semi-labile pool (NaOH-Pi) and into a stable pool (Dil. HCl P and residual-P). At the same time, organic P was transformed into inorganic P fractions which was identified by the rapid decomposition of organic P detected with solution (31)P NMR. The P transformation during pyrolysis process suggested more stable P was formed at a higher pyrolysis temperature. This result was also evidenced by the presence of less soluble or stable P species, such as such as poly-P, crandallite (CaAl3(OH)5(PO4)2) and Wavellite (Al3(OH)3(PO4)2·5H2O), as detected by solid-state (31)P NMR in biochars formed at a higher pyrolysis temperature. Furthermore, a significant proportion of less soluble pyrophosphate was identified by solution (2%-35%) and solid-state (8%-53%) (31)P NMR, which was also responsible for the stable P forms at higher pyrolysis temperature although their solubility or stability requires further investigation. Results suggested that a relatively lower pyrolysis temperature retains P availability regardless of feedstock during pyrolysis process. Copyright © 2016. Published by Elsevier B.V.

Improved Orifice Plate for Spray Gun

NASA Technical Reports Server (NTRS)

Cunningham, W.

1986-01-01

Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

Review of NMR characterization of pyrolysis oils

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

Hao, Naijia; Ben, Haoxi; Yoo, Chang Geun

Here, pyrolysis of renewable biomass has been developed as a method to produce green fuels and chemicals in response to energy security concerns as well as to alleviate environmental issues incurred with fossil fuel usage. However, pyrolysis oils still have limited commercial application, mainly because unprocessed oils cannot be readily blended with current petroleum-based transportation fuels. To better understand these challenges, researchers have applied diverse characterization techniques in the development of bio-oil studies. In particular, nuclear magnetic resonance (NMR) is a key spectroscopic characterization method through analysis of bio-oil components. This review highlights the NMR strategies for pyrolysis oil characterizationmore » and critically discusses the applications of 1H, 13C, 31P, 19F, and two-dimensional (2-D NMR) analyses such as heteronuclear single quantum correlation (HSQC) in representative pyrolysis oil studies.« less

Review of NMR characterization of pyrolysis oils

DOE PAGES

Hao, Naijia; Ben, Haoxi; Yoo, Chang Geun; ...

2016-08-24

Here, pyrolysis of renewable biomass has been developed as a method to produce green fuels and chemicals in response to energy security concerns as well as to alleviate environmental issues incurred with fossil fuel usage. However, pyrolysis oils still have limited commercial application, mainly because unprocessed oils cannot be readily blended with current petroleum-based transportation fuels. To better understand these challenges, researchers have applied diverse characterization techniques in the development of bio-oil studies. In particular, nuclear magnetic resonance (NMR) is a key spectroscopic characterization method through analysis of bio-oil components. This review highlights the NMR strategies for pyrolysis oil characterizationmore » and critically discusses the applications of 1H, 13C, 31P, 19F, and two-dimensional (2-D NMR) analyses such as heteronuclear single quantum correlation (HSQC) in representative pyrolysis oil studies.« less

In situ spray deposition of cell-loaded, thermally and chemically gelling hydrogel coatings for tissue regeneration.

PubMed

Pehlivaner Kara, Meryem O; Ekenseair, Adam K

2016-10-01

In this study, the efficacy of creating cellular hydrogel coatings on warm tissue surfaces through the minimally invasive, sprayable delivery of thermoresponsive liquid solutions was investigated. Poly(N-isopropylacrylamide)-based (pNiPAAm) thermogelling macromers with or without addition of crosslinking polyamidoamine (PAMAM) macromers were synthesized and used to produce in situ forming thermally and chemically gelling hydrogel systems. The effect of solution and process parameters on hydrogel physical properties and morphology was evaluated and compared to poly(ethylene glycol) and injection controls. Smooth, fast, and conformal hydrogel coatings were obtained when pNiPAAm thermogelling macromers were sprayed with high PAMAM concentration at low pressure. Cellular hydrogel coatings were further fabricated by different spraying techniques: single-stream, layer-by-layer, and dual stream methods. The impact of spray technique, solution formulation, pressure, and spray solution viscosity on the viability of fibroblast and osteoblast cells encapsulated in hydrogels was elucidated. In particular, the early formation of chemically crosslinked micronetworks during bulk liquid flow was shown to significantly affect cell viability under turbulent conditions compared to injectable controls. The results demonstrated that sprayable, in situ forming hydrogels capable of delivering cell populations in a homogeneous therapeutic coating on diseased tissue surfaces offer promise as novel therapies for applications in regenerative medicine. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2383-2393, 2016. © 2016 Wiley Periodicals, Inc.

Effects of Nonequilibrium Chemistry and Darcy-Forchheimer Pyrolysis Flow for Charring Ablator

NASA Technical Reports Server (NTRS)

Chen, Yih-Kanq; Milos, Frank S.

2013-01-01

The fully implicit ablation and thermal response code simulates pyrolysis and ablation of thermal protection materials and systems. The governing equations, which include energy conservation, a three-component decomposition model, and a surface energy balance, are solved with a moving grid.This work describes new modeling capabilities that are added to a special version of code. These capabilities include a time-dependent pyrolysis gas flow momentum equation with Darcy-Forchheimer terms and pyrolysis gas species conservation equations with finite rate homogeneous chemical reactions. The total energy conservation equation is also enhanced for consistency with these new additions. Two groups of parametric studies of the phenolic impregnated carbon ablator are performed. In the first group, an Orion flight environment for a proposed lunar-return trajectory is considered. In the second group, various test conditions for arcjet models are examined. The central focus of these parametric studies is to understand the effect of pyrolysis gas momentum transfer on material in-depth thermal responses with finite-rate, equilibrium, or frozen homogeneous gas chemistry. Results indicate that the presence of chemical nonequilibrium pyrolysis gas flow does not significantly alter the in-depth thermal response performance predicted using the chemical equilibrium gas model.

Validation Results for Core-Scale Oil Shale Pyrolysis

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

Staten, Josh; Tiwari, Pankaj

2015-03-01

This report summarizes a study of oil shale pyrolysis at various scales and the subsequent development a model for in situ production of oil from oil shale. Oil shale from the Mahogany zone of the Green River formation was used in all experiments. Pyrolysis experiments were conducted at four scales, powdered samples (100 mesh) and core samples of 0.75”, 1” and 2.5” diameters. The batch, semibatch and continuous flow pyrolysis experiments were designed to study the effect of temperature (300°C to 500°C), heating rate (1°C/min to 10°C/min), pressure (ambient and 500 psig) and size of the sample on product formation.more » Comprehensive analyses were performed on reactants and products - liquid, gas and spent shale. These experimental studies were designed to understand the relevant coupled phenomena (reaction kinetics, heat transfer, mass transfer, thermodynamics) at multiple scales. A model for oil shale pyrolysis was developed in the COMSOL multiphysics platform. A general kinetic model was integrated with important physical and chemical phenomena that occur during pyrolysis. The secondary reactions of coking and cracking in the product phase were addressed. The multiscale experimental data generated and the models developed provide an understanding of the simultaneous effects of chemical kinetics, and heat and mass transfer on oil quality and yield. The comprehensive data collected in this study will help advance the move to large-scale in situ oil production from the pyrolysis of oil shale.« less

Effect of pyrolysis temperature on chemical form, behavior and environmental risk of Zn, Pb and Cd in biochar produced from phytoremediation residue.

PubMed

Huang, Hui; Yao, Wenlin; Li, Ronghua; Ali, Amjad; Du, Juan; Guo, Di; Xiao, Ran; Guo, Zhanyu; Zhang, Zengqiang; Awasthi, Mukesh Kumar

2018-02-01

This study aimed to evaluate the chemical forms, behavior and environmental risk of heavy metal (HMs) Zn, Pb and Cd in phytoremediation residue (PMR) pyrolyzed at 350 °C, 550 °C and 750 °C, respectively. The behavior of HMs variation during the PMR pyrolysis process was analyzed and the potential HMs environmental risk of phytoremediation residue biochars (PMB) was assessed which was seldom investigated before. The results showed that the pyrolysis temperature increase decreased the soluble/exchangeable HMs fraction and alleviated the HMs bioavailability. When the temperature was over 550 °C, the adsorbed Zn(II), Pb(II) and Cd(II) were turned into oxides forms and concentrated in PMB with more stable forms exhibiting lower risk assessment code and potential ecological risk index. The ecotoxicity test showed higher pyrolysis temperature favored the reduction of PMB ecotoxicity. It is suggested that pyrolysis temperature above 550°C may be suitable for thermal treatment of PMR with acceptable environmental risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of hydrothermal treatment on the pyrolysis behavior of Chinese fan palm.

PubMed

Yao, Zhongliang; Ma, Xiaoqian

2018-01-01

The effect of hydrothermal treatment (HTT) on Chinese fan palm pyrolysis was investigated. It indicated that HTT could effectively remove a large portion of alkali/alkaline earth metals and disrupt the chemical structure to a certain extent. HTT delayed the initial decomposition temperature but accelerated the pyrolysis process completely. HTT also increased the relative contents of both sugars and hydrocarbons in pyrolysis. At 210°C, HTT had the most significant promotion effect on the sugars formation with the relative content of 30.58%. While, The relative content of phenols, acids, furans, aldehydes, esters and CO 2 decreased more or less after HTT. With increasing pyrolysis temperature, the relative content of most groups of chemicals except hydrocarbons decreased. Response contours were analyzed to find the optimal reaction conditions for generating acids, phenols, sugars and hydrocarbons, respectively. The results indicated both pyrolysis temperature and HTT temperature had distinct influence on relative contents of products. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Spray deposited gallium doped tin oxide thinfilm for acetone sensor application

NASA Astrophysics Data System (ADS)

Preethi, M. S.; Bharath, S. P.; Bangera, Kasturi V.

2018-04-01

Undoped and gallium doped (1 at.%, 2 at.% and 3 at.%) tin oxide thin films were prepared using spray pyrolysis technique by optimising the deposition conditions such as precursor concentration, substrate temperature and spraying rate. X-ray diffraction analysis revealed formation of tetragonally structured polycrystalline films. The SEM micrographs of Ga doped films showed microstructures. The electrical resistivity of the doped films was found to be more than that of the undoped films. The Ga-doped tin oxide thin films were characterised for gas sensors. 1 at.% Ga doped thin films were found to be better acetone gas sensor, showed 68% sensitivity at 350°C temperature.

Luminescence optimization of MBO 3:Eu 3+ (M=Y, Gd, Al) red phosphor by spray pyrolysis using combinatorial chemistry

NASA Astrophysics Data System (ADS)

Youl Jung, Kyeong

2010-08-01

Conventional solution-based combinatorial chemistry was combined with spray pyrolysis and applied to optimize the luminescence properties of (Y x, Gd y, Al z)BO 3:Eu 3+ red phosphor under vacuum ultraviolet (VUV) excitation. For the Y-Gd-Al ternary system, a compositional library was established to seek the optimal composition at which the highest luminescence under VUV (147 nm) excitation could be achieved. The Al content was found to mainly control the relative peak ratio (R/O) of red and orange colors due to the 5D 0→ 7F 2 to 5D 0→ 7F 1 transitions of Eu 3+. The substitution of Gd atoms in the place of Y sites did not contribute to change the R/O ratio, but was helpful to enhance the emission intensity. As a result, the 613 nm emission peak due to the 5D 0→ 7F 2 transitions of Eu 3+ was intensified by increasing the Al/Gd ratio at a fixed Y content, resulting in the improvement of the color coordinate. Finally, the optimized host composition was (Y 0.11, Gd 0.10, Al 0.79)BO 3 in terms of the emission intensity at 613 nm and the color coordinate.

RETRACTED: Chemical densification of plasma sprayed yttria stabilized zirconia (YSZ) coatings for high temperature wear and corrosion resistance

NASA Astrophysics Data System (ADS)

Ye, Yaping; Fehr, Karl Thomas; Faulstich, Martin; Wolf, Gerhard

2012-12-01

Plasma-sprayed yttria stabilized zirconia (YSZ) ceramic coatings have been widely used as wear- and corrosion-resistant coatings in high temperature applications and an aggressive environment due to their high hardness, wear resistance, heat and chemical resistance, and low thermal conductivity. The highly porous structure of plasma-sprayed ceramic coatings and their poor adhesion to the substrate usually lead to the coating degradation and failure. In this study, a two-layer system consisting of atmospheric plasma-sprayed 8 wt.% yttria-stabilized zirconia (8YSZ) and Ni-based alloy coatings was post-treated by means of a novel chemical sealing process at moderate temperatures of 600-800 °C. Microstructure characteristics of the YSZ coatings were studied using an electron probe micro-analyzer (EPMA). Results revealed that the ceramic top coat was densified by the precipitated zirconia in the open pores. Therefore, the sealed YSZ coatings exhibit reduced porosity, higher hardness and a better adhesion onto the bond coat. The mechanisms for the sealing process were also proposed.

Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

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

Shasti, M.; Mortezaali, A., E-mail: mortezaali@alzahra.ac.ir; Dariani, R. S.

2015-01-14

In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Simore » photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.« less

Modifications Of A Commercial Spray Gun

NASA Technical Reports Server (NTRS)

Allen, Peter B.

1993-01-01

Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

Comparison of Physical-chemical and Mechanical Properties of Chlorapatite and Hydroxyapatite Plasma Sprayed Coatings

PubMed Central

Demnati, Imane; Grossin, David; Marsan, Olivier; Bertrand, Ghislaine; Collonges, Gérard; Combes, Christèle; Parco, Maria; Braceras, Inigo; Alexis, Joel; Balcaen, Yannick; Rey, Christian

2015-01-01

Chlorapatite can be considered a potential biomaterial for orthopaedic applications. Its use as plasma-sprayed coating could be of interest considering its thermal properties and particularly its ability to melt without decomposition unlike hydroxyapatite. Chlorapatite (ClA) was synthesized by a high-temperature ion exchange reaction starting from commercial stoichiometric hydroxyapatites (HA). The ClA powder showed similar characteristics as the original industrial HA powder, and was obtained in the monoclinic form. The HA and ClA powders were plasma-sprayed using a low-energy plasma spraying system with identical processing parameters. The coatings were characterized by physical-chemical methods, i.e. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, including distribution mapping of the main phases detected such as amorphous calcium phosphate (ACP), oxyapatite (OA), and HA or ClA. The unexpected formation of oxyapatite in ClA coatings was assigned to a side reaction with contaminating oxygenated species (O2, H2O). ClA coatings exhibited characteristics different from HA, showing a lower content of oxyapatite and amorphous phase. Although their adhesion strength was found to be lower than that of HA coatings, their application could be an interesting alternative, offering, in particular, a larger range of spraying conditions without formation of massive impurities. PMID:25893015

Fabrication, characterization and applications of iron selenide

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

Hussain, Raja Azadar, E-mail: hussainazadar@yahoo.com; Badshah, Amin; Lal, Bhajan

This review article presents fabrication of FeSe by solid state reactions, solution chemistry routes, chemical vapor deposition, spray pyrolysis and chemical vapor transport. Different properties and applications such as crystal structure and phase transition, band structure, spectroscopy, superconductivity, photocatalytic activity, electrochemical sensing, and fuel cell activity of FeSe have been discussed. - Graphical abstract: Iron selenide can be synthesized by solid state reactions, chemical vapor deposition, solution chemistry routes, chemical vapor transport and spray pyrolysis. - Highlights: • Different fabrication methods of iron selenide (FeSe) have been reviewed. • Crystal structure, band structure and spectroscopy of FeSe have been discussed.more » • Superconducting, catalytic and fuel cell application of FeSe have been presented.« less

Effects of biopretreatment on pyrolysis behaviors of corn stalk by methanogen.

PubMed

Wang, Tipeng; Ye, Xiaoning; Yin, Jun; Lu, Qiang; Zheng, Zongming; Dong, Changqing

2014-07-01

The study investigated the effects of methanogen pretreatment on pyrolysis behaviors of corn stalk (CS) by using Py-GC/MS analysis and thermogravimetric analysis. Results indicated that biopretreatment changed considerably the pyrolysis behaviors of CS from four weight loss stages to two weight loss stages. Increasing biopretreatment time from 5 days to 25 days enhanced the kinds and contents of chemicals in volatile products. In pyrolysis products, the contents of sugars, linear ketones and furans decreased from 1.43%, 12.60% and 7.38% to 1.25%, 10.22% and 3.25%, respectively, and the contents of phenols increased from 15.08% to 27.84%. The most content change from 6.83% to 13.63% indicated that methanogen pretreatment improved the pyrolysis selectivity of CS to product the 4-VP, but it was disadvantageous to 5-hydroxymethyl furfural, levoglucose and furfural. The changes of chemical compositions and structure of CS after biopretreatment were the main reason of the differences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vacuum pyrolysis of waste tires with basic additives.

PubMed

Zhang, Xinghua; Wang, Tiejun; Ma, Longlong; Chang, Jie

2008-11-01

Granules of waste tires were pyrolyzed under vacuum (3.5-10 kPa) conditions, and the effects of temperature and basic additives (Na2CO3, NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 degrees C to 600 degrees C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48 wt% was achieved at 550 degrees C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50 wt% was achieved at 480 degrees C by adding 3 wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) approximately 205 degrees C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39 wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na2CO3 addition. Pyrolysis gas was mainly composed of H2, CO, CH4, CO2, C2H4 and C2H6. Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5 wt%) was much higher.

Integrated supply chain design for commodity chemicals production via woody biomass fast pyrolysis and upgrading.

PubMed

Zhang, Yanan; Hu, Guiping; Brown, Robert C

2014-04-01

This study investigates the optimal supply chain design for commodity chemicals (BTX, etc.) production via woody biomass fast pyrolysis and hydroprocessing pathway. The locations and capacities of distributed preprocessing hubs and integrated biorefinery facilities are optimized with a mixed integer linear programming model. In this integrated supply chain system, decisions on the biomass chipping methods (roadside chipping vs. facility chipping) are also explored. The economic objective of the supply chain model is to maximize the profit for a 20-year chemicals production system. In addition to the economic objective, the model also incorporates an environmental objective of minimizing life cycle greenhouse gas emissions, analyzing the trade-off between the economic and environmental considerations. The capital cost, operating cost, and revenues for the biorefinery facilities are based on techno-economic analysis, and the proposed approach is illustrated through a case study of Minnesota, with Minneapolis-St. Paul serving as the chemicals distribution hub. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of spray angle and spray volume on deposition of a medium droplet spray with air support in ivy pot plants.

PubMed

Foqué, Dieter; Pieters, Jan G; Nuyttens, David

2014-03-01

Spray boom systems, an alternative to the predominantly-used spray guns, have the potential to considerably improve crop protection management in glasshouses. Based on earlier experiments, the further optimization of the deposits of a medium spray quality extended range flat fan nozzle type using easy adjustable spray boom settings was examined. Using mineral chelate tracers and water sensitive papers, the spray results were monitored at three plant levels, on the upper side and the underside of the leaves, and on some off-target collectors. In addition, the deposition datasets of all tree experiments were compared. The data showed that the most efficient spray distribution with the medium spray quality flat fan nozzles was found with a 30° forward angled spray combined with air support and an application rate of 1000 L ha(-1) . This technique resulted in a more uniform deposition in the dense canopy and increased spray deposition on the lower side of the leaves compared with the a standard spray boom application. Applying 1000 L ha(-1) in two subsequent runs instead of one did not seem to show any added value. Spray deposition can be improved hugely simply by changing some spray boom settings like nozzle type, angling the spray, using air support and adjusting the spray volume to the crop. © 2013 Society of Chemical Industry.

The effect of clay catalyst on the chemical composition of bio-oil obtained by co-pyrolysis of cellulose and polyethylene

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

Solak, Agnieszka; Rutkowski, Piotr, E-mail: piotr.rutkowski@pwr.wroc.pl

2014-02-15

Highlights: • Non-catalytic and catalytic fast pyrolysis of cellulose/polyethylene blend was carried out in a laboratory scale reactor. • Optimization of process temperature was done. • Optimization of clay catalyst type and amount for co-pyrolysis of cellulose and polyethylene was done. • The product yields and the chemical composition of bio-oil was investigated. - Abstract: Cellulose/polyethylene (CPE) mixture 3:1, w/w with and without three clay catalysts (K10 – montmorillonite K10, KSF – montmorillonite KSF, B – Bentonite) addition were subjected to pyrolysis at temperatures 400, 450 and 500 °C with heating rate of 100 °C/s to produce bio-oil with highmore » yield. The pyrolytic oil yield was in the range of 41.3–79.5 wt% depending on the temperature, the type and the amount of catalyst. The non-catalytic fast pyrolysis at 500 °C gives the highest yield of bio-oil (79.5 wt%). The higher temperature of catalytic pyrolysis of cellulose/polyethylene mixture the higher yield of bio-oil is. Contrarily, increasing amount of montmorillonite results in significant, almost linear decrease in bio-oil yield followed by a significant increase of gas yield. The addition of clay catalysts to CPE mixture has a various influence on the distribution of bio-oil components. The addition of montmorillonite K10 to cellulose/polyethylene mixture promotes the deepest conversion of polyethylene and cellulose. Additionally, more saturated than unsaturated hydrocarbons are present in resultant bio-oils. The proportion of liquid hydrocarbons is the highest when a montmorillonite K10 is acting as a catalyst.« less

Investigations on structural, vibrational, morphological and optical properties of CdS and CdS/Co films by ultrasonic spray pyrolysis

NASA Astrophysics Data System (ADS)

Aksay, S.; Polat, M.; Özer, T.; Köse, S.; Gürbüz, G.

2011-09-01

CdS and CdS/Co films have been deposited on glass substrates by an ultrasonic spray pyrolysis method. The effects of Co incorporation on the structural, optical, morphological, elemental and vibrational properties of these films were investigated. XRD analysis confirmed the hexagonal wurtzite structure of all films and had no impurity phase. While CdS film has (0 0 2) as the preferred orientation, CdS/Co films have (1 1 0) as the preferred orientation. The direct optical band gap was found to decrease from 2.42 to 2.39 eV by Co incorporation. The decrease of the direct energy gaps by increasing Co contents is mainly due to the sp-d exchange interaction between the localized d-electrons of Co2+ ions and band electrons of CdS. After the optical investigations, it was seen that the transmittance of CdS films decreased by Co content. The Raman measurements revealed two peaks corresponding to the 1LO and 2LO modes of hexagonal CdS. The vibrational modes of Cd-S were obtained in the wavenumber range (590-715 cm-1) using Fourier transform infrared spectroscopy (FTIR). The elemental analysis of the film was done by energy dispersive X-ray spectrometry.

Derivation of hydrous pyrolysis kinetic parameters from open-system pyrolysis

NASA Astrophysics Data System (ADS)

Tseng, Yu-Hsin; Huang, Wuu-Liang

2010-05-01

Kinetic information is essential to predict the temperature, timing or depth of hydrocarbon generation within a hydrocarbon system. The most common experiments for deriving kinetic parameters are mainly by open-system pyrolysis. However, it has been shown that the conditions of open-system pyrolysis are deviant from nature by its low near-ambient pressure and high temperatures. Also, the extrapolation of heating rates in open-system pyrolysis to geological conditions may be questionable. Recent study of Lewan and Ruble shows hydrous-pyrolysis conditions can simulate the natural conditions better and its applications are supported by two case studies with natural thermal-burial histories. Nevertheless, performing hydrous pyrolysis experiment is really tedious and requires large amount of sample, while open-system pyrolysis is rather convenient and efficient. Therefore, the present study aims at the derivation of convincing distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data. Our results unveil that there is a good correlation between open-system Rock-Eval parameter Tmax and the activation energy (Ea) derived from hydrous pyrolysis. The hydrous pyrolysis single Ea can be predicted from Tmax based on the correlation, while the frequency factor (A0) is estimated based on the linear relationship between single Ea and log A0. Because the Ea distribution is more rational than single Ea, we modify the predicted single hydrous pyrolysis Ea into distributed Ea by shifting the pattern of Ea distribution from open-system pyrolysis until the weight mean Ea distribution equals to the single hydrous pyrolysis Ea. Moreover, it has been shown that the shape of the Ea distribution is very much alike the shape of Tmax curve. Thus, in case of the absence of open-system Ea distribution, we may use the shape of Tmax curve to get the distributed hydrous pyrolysis Ea. The study offers a new approach as a simple method for obtaining distributed hydrous pyrolysis

Tuning the surface morphology of aluminium doped zinc oxide thin films by arrayed nanorods through chemical growth process

NASA Astrophysics Data System (ADS)

Devasia, Sebin; Anila, E. I.

2018-04-01

Here we report the growth and characterization of chemically grown aluminium doped zinc oxide nanorods on seed layers. The seed layers were prepared by chemical spray pyrolysis which acted as the growth centers. The growth duration of nanorods were varied from 3h to 12h in steps of 3h. Further, investigations on their structural, morphological, electrical and optical properties. The SEM images confirmed the hexagonal shaped nanorod arrays grown on the seed layers. Later, the x-ray diffraction measurements revealed the pure zinc oxide phase of the samples. Photoluminescence and photoconductivity studies were carried out to analyze the potential of its optoelectronic properties.

The Influence of Process Conditions on the Chemical Composition of Pine Wood Catalytic Pyrolysis Oils

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

Pereira, J.; Agblevor, F. A.; Beis, S. H.

Pine wood samples were used as model feedstock to study the properties of catalytic fast pyrolysis oils. The influence of two commercial zeolite catalysts (BASF and SudChem) and pretreatment of the pine wood with sodium hydroxide on pyrolysis products were investigated. The pyrolysis oils were first fractionated using column chromatography and characterized using GC-MS. Long chain aliphatic hydrocarbons, levoglucosan, aldehydes and ketones, guaiacols/syringols, and benzenediols were the major compounds identified in the pyrolysis oils. The catalytic pyrolysis increased the polycyclic hydrocarbons fraction. Significant decreases in phthalate derivatives using SudChem and long chain aliphatics using BASF catalyst were observed. Significant amountsmore » of aromatic heterocyclic hydrocarbons and benzene derivatives were formed, respectively, using BASF and SudChem catalysts. Guaiacyl/syringyl and benzenediols derivatives were partly suppressed by the zeolite catalysts, while the sodium hydroxide treatment enriched phenolic derivatives. Zeolite catalyst and sodium hydroxide were employed together; they showed different results for each catalyst.« less

The Influence of Process Conditions on the Chemical Composition of Pine Wood Catalytic Pyrolysis Oils

DOE PAGES

Pereira, J.; Agblevor, F. A.; Beis, S. H.

2012-01-01

Pine wood samples were used as model feedstock to study the properties of catalytic fast pyrolysis oils. The influence of two commercial zeolite catalysts (BASF and SudChem) and pretreatment of the pine wood with sodium hydroxide on pyrolysis products were investigated. The pyrolysis oils were first fractionated using column chromatography and characterized using GC-MS. Long chain aliphatic hydrocarbons, levoglucosan, aldehydes and ketones, guaiacols/syringols, and benzenediols were the major compounds identified in the pyrolysis oils. The catalytic pyrolysis increased the polycyclic hydrocarbons fraction. Significant decreases in phthalate derivatives using SudChem and long chain aliphatics using BASF catalyst were observed. Significant amountsmore » of aromatic heterocyclic hydrocarbons and benzene derivatives were formed, respectively, using BASF and SudChem catalysts. Guaiacyl/syringyl and benzenediols derivatives were partly suppressed by the zeolite catalysts, while the sodium hydroxide treatment enriched phenolic derivatives. Zeolite catalyst and sodium hydroxide were employed together; they showed different results for each catalyst.« less

Biotechnological Perspectives of Pyrolysis Oil for a Bio-Based Economy.

PubMed

Arnold, Stefanie; Moss, Karin; Henkel, Marius; Hausmann, Rudolf

2017-10-01

Lignocellulosic biomass is an important feedstock for a potential future bio-based economy. Owing to its compact structure, suitable decomposition technologies will be necessary to make it accessible for biotechnological conversion. While chemical and enzymatic hydrolysis are currently established methods, a promising alternative is provided by fast pyrolysis. The main resulting product thereof, referred to as pyrolysis oil, is an energy-rich and easily transportable liquid. Many of the identified constituents of pyrolysis oil, however, have previously been reported to display adverse effects on microbial growth. In this Opinion we discuss relevant biological, biotechnological, and technological challenges that need to be addressed to establish pyrolysis oil as a reliable microbial feedstock for a bio-based economy of the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Slow pyrolysis polygeneration of bamboo (Phyllostachys pubescens): Product yield prediction and biochar formation mechanism.

PubMed

Wang, Huihui; Wang, Xin; Cui, Yanshan; Xue, Zhongcai; Ba, Yuxin

2018-05-11

Slow pyrolysis of bamboo was conducted at 400-600 °C and pyrolysis products were characterized with FTIR, BET, XRD, SEM, EDS and GC to establish a pyrolysis product yield prediction model and biochar formation mechanism. Pyrolysis biochar yield was predicted based on content of cellulose, hemicellulose and lignin in biomass with their carbonization index of 0.20, 0.35 and 0.45. The formation mechanism of porous structure in pyrolysis biochar was established based on its physicochemical property evolution and emission characteristics of pyrolysis gas. The main components (cellulose, hemicellulose and lignin) had different pyrolysis or chemical reaction pathways to biochar. Lignin had higher aromatic structure, which resulted higher biochar yield. It was the main biochar precursor during biomass pyrolysis. Cellulose was likely to improve porous structure of pyrolysis biochar due to its high mass loss percentage. Higher pyrolysis temperatures (600 °C) promoted inter- and intra-molecular condensation reactions and aromaticity in biochar. Copyright © 2018 Elsevier Ltd. All rights reserved.

Production of activated carbon by using pyrolysis process in an ammonia atmosphere

NASA Astrophysics Data System (ADS)

Indayaningsih, N.; Destyorini, F.; Purawiardi, R. I.; Insiyanda, D. R.; Widodo, H.

2017-04-01

Activated carbon is materials that have wide applications, including supercapacitor materials, absorbent in chemical industry, and absorbent material in the chemical industry. This study has carried out for the manufacturing of activated carbon from inexpensive materials through efficient processes. Carbon material was made from coconut fibers through pyrolysis process at temperature of 650, 700, 750 and 800°C. Aim of this study was to obtain carbon material that has a large surface area. Pyrolysis process is carried out in an inert atmosphere (N2 gas) at a temperature of 450°C for 30 minutes, followed by pyrolysis process in an ammonia atmosphere at 800°C for 2 hours. The pyrolysis results showed that the etching process in ammonia is occurred; as it obtained some greater surface area when compared with the pyrolisis process in an atmosphere by inert gas only. The resulted activated carbon also showed to have good properties in surface area and total pore volume.

Effects of chemical form of sodium on the product characteristics of alkali lignin pyrolysis.

PubMed

Guo, Da-liang; Yuan, Hong-you; Yin, Xiu-li; Wu, Chuang-zhi; Wu, Shu-bin; Zhou, Zhao-qiu

2014-01-01

The effects of Na as organic bound form or as inorganic salts form on the pyrolysis products characteristics of alkali lignin were investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR), tube furnace and thermo-gravimetric analyzer (TGA). Results of TG-FTIR and tube furnace indicated that the two chemical forms Na reduced the releasing peak temperature of CO and phenols leading to the peak temperature of the maximum mass loss rate shifted to low temperature zone. Furthermore, organic bound Na obviously improved the elimination of alkyl substituent leading to the yields of phenol and guaiacol increased, while inorganic Na increased the elimination of phenolic hydroxyl groups promoting the formation of ethers. It was also found the two chemical forms Na had different effects on the gasification reactivity of chars. For inorganic Na, the char conversion decreased with increasing the char forming temperature, while organic bound Na was opposite. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Visible light assisted photoelectrocatalytic degradation of sugarcane factory wastewater by sprayed CZTS thin films

NASA Astrophysics Data System (ADS)

Hunge, Y. M.; Mahadik, M. A.; Patil, V. L.; Pawar, A. R.; Gadakh, S. R.; Moholkar, A. V.; Patil, P. S.; Bhosale, C. H.

2017-12-01

Highly crystalline Cu2ZnSnS4 (CZTS) thin films have been deposited onto glass and FTO coated glass substrates by simple chemical spray-pyrolysis technique. It is an important material for solar energy conversion through the both photovoltaics and photocatalysis. The effect of substrate temperatures on the physico-chemical properties of the CZTS films is studied. The XRD study shows the formation of single phase CZTS with kesterite structure. FE-SEM analysis reveals nano flakes architecture with pin-hole and crake free surface with more adherent. The film deposited at optimized substrate temperature exhibits optical band gap energy of 1.90 eV, which lies in the visible region of the solar spectrum and useful for photocatalysis application. The photoelectrocatalytic activities of the large surface area (10 × 10 cm2) deposited CZTS thin film photocatalysts were evaluated for the degradation of sugarcane factory wastewater under visible light irradiation. The results show that the CZTS thin film photocatalyst exhibited about 90% degradation of sugar cane factory wastewater. The mineralization of sugarcane factory wastewater is studied by measuring chemical oxygen demand (COD) values.

Improving biomass pyrolysis economics by integrating vapor and liquid phase upgrading

DOE PAGES

Iisa, Kristiina; Robichaud, David J.; Watson, Michael J.; ...

2017-11-24

Partial deoxygenation of bio-oil by catalytic fast pyrolysis with subsequent coupling and hydrotreating can lead to improved economics and will aid commercial deployment of pyrolytic conversion of biomass technologies. Biomass pyrolysis efficiently depolymerizes and deconstructs solid plant matter into carbonaceous molecules that, upon catalytic upgrading, can be used for fuels and chemicals. Upgrading strategies include catalytic deoxygenation of the vapors before they are condensed (in situ and ex situ catalytic fast pyrolysis), or hydrotreating following condensation of the bio-oil. In general, deoxygenation carbon efficiencies, one of the most important cost drivers, are typically higher for hydrotreating when compared to catalyticmore » fast pyrolysis alone. However, using catalytic fast pyrolysis as the primary conversion step can benefit the entire process chain by: (1) reducing the reactivity of the bio-oil, thereby mitigating issues with aging and transport and eliminating need for multi-stage hydroprocessing configurations; (2) producing a bio-oil that can be fractionated through distillation, which could lead to more efficient use of hydrogen during hydrotreating and facilitate integration in existing petroleum refineries; and (3) allowing for the separation of the aqueous phase. In this perspective, we investigate in detail a combination of these approaches, where some oxygen is removed during catalytic fast pyrolysis and the remainder removed by downstream hydrotreating, accompanied by carbon–carbon coupling reactions in either the vapor or liquid phase to maximize carbon efficiency toward value-driven products (e.g. fuels or chemicals). The economic impact of partial deoxygenation by catalytic fast pyrolysis will be explored in the context of an integrated two-stage process. In conclusion, improving the overall pyrolysis-based biorefinery economics by inclusion of production of high-value co-products will be examined.« less

Improving biomass pyrolysis economics by integrating vapor and liquid phase upgrading

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

Iisa, Kristiina; Robichaud, David J.; Watson, Michael J.

Partial deoxygenation of bio-oil by catalytic fast pyrolysis with subsequent coupling and hydrotreating can lead to improved economics and will aid commercial deployment of pyrolytic conversion of biomass technologies. Biomass pyrolysis efficiently depolymerizes and deconstructs solid plant matter into carbonaceous molecules that, upon catalytic upgrading, can be used for fuels and chemicals. Upgrading strategies include catalytic deoxygenation of the vapors before they are condensed (in situ and ex situ catalytic fast pyrolysis), or hydrotreating following condensation of the bio-oil. In general, deoxygenation carbon efficiencies, one of the most important cost drivers, are typically higher for hydrotreating when compared to catalyticmore » fast pyrolysis alone. However, using catalytic fast pyrolysis as the primary conversion step can benefit the entire process chain by: (1) reducing the reactivity of the bio-oil, thereby mitigating issues with aging and transport and eliminating need for multi-stage hydroprocessing configurations; (2) producing a bio-oil that can be fractionated through distillation, which could lead to more efficient use of hydrogen during hydrotreating and facilitate integration in existing petroleum refineries; and (3) allowing for the separation of the aqueous phase. In this perspective, we investigate in detail a combination of these approaches, where some oxygen is removed during catalytic fast pyrolysis and the remainder removed by downstream hydrotreating, accompanied by carbon–carbon coupling reactions in either the vapor or liquid phase to maximize carbon efficiency toward value-driven products (e.g. fuels or chemicals). The economic impact of partial deoxygenation by catalytic fast pyrolysis will be explored in the context of an integrated two-stage process. In conclusion, improving the overall pyrolysis-based biorefinery economics by inclusion of production of high-value co-products will be examined.« less

Exposure of spray-men to dieldrin in residual spraying

PubMed Central

Fletcher, T. E.; Press, J. M.; Wilson, D. Bagster

1959-01-01

A study of the exposure of spray-men to dieldrin was made in a pilot scheme of residual spraying in the Taveta-Pare area of East Africa. A detailed work study was completed on the operators, and sources of contamination were enumerated. Filter paper pads were placed on the skin and outside clothing and the pick-up was estimated chemically. A spray-man, while using the daily average of 2.12 kg (4.7 pounds) of dieldrin and observing the protective measures laid down, received a dermal exposure of 1.8 mg of dieldrin per kg of body-weight per day. This was possibly reduced somewhat by washing with soap and water upon completion of each day's work. The sixteen spray-men and assistants were exposed for 180 days per year and there was an interim period of 2 months between spray cycles. No clinical symptoms of poisoning were observed. Comparison is made with certain programmes where dieldrin poisoning has occurred. Attention is drawn to the reduced time of exposure in the Taveta-Pare scheme, personal washing, the great value of protective clothing and of its daily washing in soap and water and the need to use a dilute suspension of wettable powder for spraying. Imagesp16-a PMID:13638786

Effects of nozzle type and spray angle on spray deposition in ivy pot plants.

PubMed

Foqué, Dieter; Nuyttens, David

2011-02-01

Fewer plant protection products are now authorised for use in ornamental growings. Frequent spraying with the same product or a suboptimal technique can lead to resistance in pests and diseases. Better application techniques could improve the sustainable use of the plant protection products still available. Spray boom systems--instead of the still predominantly used spray guns--might improve crop protection management in greenhouses considerably. The effect of nozzle type, spray pressure and spray angle on spray deposition and coverage in ivy pot plants was studied, with a focus on crop penetration and spraying the bottom side of the leaves in this dense crop. The experiments showed a significant and important effect of collector position on deposition and coverage in the plant. Although spray deposition and coverage on the bottom side of the leaves are generally low, they could be improved 3.0-4.9-fold using the appropriate application technique. When using a spray boom in a dense crop, the nozzle choice, spray pressure and spray angle should be well considered. The hollow-cone, the air-inclusion flat-fan and the standard flat-fan nozzle with an inclined spray angle performed best because of the effect of swirling droplets, droplets with a high momentum and droplet direction respectively. Copyright © 2010 Society of Chemical Industry.

Mechanism of Microwave-Assisted Pyrolysis of Glucose to Furfural Revealed by Isotopic Tracer and Quantum Chemical Calculations.

PubMed

Bao, Liwei; Shi, Lei; Luo, Hu; Kong, Lingzhao; Li, Shenggang; Wei, Wei; Sun, Yuhan

2017-08-10

Glucose labeled with 13 C or 18 O was used to investigate the mechanism of its conversion into furfural by microwaveassisted pyrolysis. The isotopic content and location in furfural were determined from GC-MS and 13 C NMR spectroscopic measurements and data analysis. The results suggest that the carbon skeleton in furfural is mainly derived from C1 to C5 of glucose, whereas the C of the aldehyde group and the O of the furan ring in furfural primarily originate from C1 and O5 of glucose, respectively. For the first time, the source of O in the furan ring of furfural was elucidated directly by experiment, providing results that are consistent with predictions from recent quantum chemical calculations. Moreover, further theoretical calculations indicate substantially lower energy barriers than previous predictions by considering the potential catalytic effect of formic acid, which is one of the pyrolysis products. The catalytic role of formic acid is further confirmed by experimental evidence. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method for Hot Real-Time Sampling of Pyrolysis Vapors

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

Pomeroy, Marc D

Biomass Pyrolysis has been an increasing topic of research, in particular as a replacement for crude oil. This process utilizes moderate temperatures to thermally deconstruct the biomass which is then condensed into a mixture of liquid oxygenates to be used as fuel precursors. Pyrolysis oils contain more than 400 compounds, up to 60 percent of which do not re-volatilize for subsequent chemical analysis. Vapor chemical composition is also complicated as additional condensation reactions occur during the condensation and collection of the product. Due to the complexity of the pyrolysis oil, and a desire to catalytically upgrade the vapor composition beforemore » condensation, online real-time analytical techniques such as Molecular Beam Mass Spectrometry (MBMS) are of great use. However, in order to properly sample hot pyrolysis vapors, many challenges must be overcome. Sampling must occur within a narrow range of temperatures to reduce product composition changes from overheating or partial condensation or plugging of lines from condensed products. Residence times must be kept at a minimum to reduce further reaction chemistries. Pyrolysis vapors also form aerosols that are carried far downstream and can pass through filters resulting in build-up in downstream locations. The co-produced bio-char and ash from the pyrolysis process can lead to plugging of the sample lines, and must be filtered out at temperature, even with the use of cyclonic separators. A practical approach for considerations and sampling system design, as well as lessons learned are integrated into the hot analytical sampling system of the National Renewable Energy Laboratory's (NREL) Thermochemical Process Development Unit (TCPDU) to provide industrially relevant demonstrations of thermochemical transformations of biomass feedstocks at the pilot scale.« less

Mineral nutrient recovery from pyrolysis systems

USDA-ARS?s Scientific Manuscript database

Bioenergy crops such as high-energy sorghum (HES), bioenergy rice, corn stover, and switchgrass can be thermo-chemically converted by pyrolysis to produce bio-oil, synthesis gas from non-condensable gases, and biochar. The biochar fraction can be recycled back to the production field to improve soil...

Recent developments in fast pyrolysis of ligno-cellulosic materials.

PubMed

Kersten, Sascha; Garcia-Perez, Manuel

2013-06-01

Pyrolysis is a thermochemical process to convert ligno-cellulosic materials into bio-char and pyrolysis oil. This oil can be further upgraded or refined for electricity, transportation fuels and chemicals production. At the time of writing, several demonstration factories are considered worldwide aiming at maturing the technology. Research is focusing on understanding the underlying processes at all relevant scales, ranging from the chemistry of cell wall deconstruction to optimization of pyrolysis factories, in order to produce better quality oils for targeted uses. Among the several bio-oil applications that are currently investigated the production and fermentation of pyrolytic sugars explores the promising interface between thermochemistry and biotechnology. Copyright © 2013 Elsevier Ltd. All rights reserved.

H2 Production Under Visible Light Irradiation from Aqueous Methanol Solution on CaTiO3:Cu Prepared by Spray Pyrolysis

NASA Astrophysics Data System (ADS)

Lim, Sung Nam; Song, Shin Ae; Jeong, Yong-Cheol; Kang, Hyun Woo; Park, Seung Bin; Kim, Ki Young

2017-10-01

Perovskite-type photocatalysts of CaCu x Ti1- x O3 (0 ≤ x ≤ 0.02) powder were prepared by spray pyrolysis of aqueous solution or aqueous solution with polymeric additive. The effects of the amount of copper ions doped in the photocatalyst and the precursor type on the photocatalytic activity under visible-light irradiation were investigated. The crystal structure, oxidation state, and light adsorption properties of the prepared photocatalysts were analyzed using x-ray diffraction, x-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy, respectively. The doping of copper ions in CaTiO3 allowed visible-light absorption owing to a narrowing of the band gap energy of the host material through the formation of a new donor level for copper ions. Among the doped samples prepared from the aqueous precursor, CaTiO3 doped with 1 mol.% copper ions had the highest hydrogen evolution rate (140.7 μmol g-1 h-1). Notably, the hydrogen evolution rate of the photocatalyst doped with 1 mol.% copper ions prepared from the aqueous precursor with polymeric additive (295.0 μmol g-1 h-1) was two times greater than that prepared from the aqueous precursor, due to the morphology effect.

Effect of phytoplankton biomass in seawater on chemical properties of sea spray aerosols.

PubMed

Park, Jiyeon; Kim, Dohyung; Lee, Kwangyul; Han, Seunghee; Kim, Hyunji; Williams, Leah R; Joo, Hung Soo; Park, Kihong

2016-09-15

This study is to investigate the effect of biological seawater properties on sea spray aerosols (SSA). Concentrations of chlorophyll-a and bacteria were measured at coastal site in Korea in fall and summer seasons. Also, aerosol mass spectrometer (AMS) was used to determine chemical constituents (organics, sulfate, nitrate, ammonium, and chloride) of non-refractory submicrometer aerosols sprayed from seawaters using a bubble bursting system. The average concentration of chlorophyll-a in seawater in fall was 1.75±0.78μg/l, whereas it significantly increased to 5.11±2.16μg/l in summer. It was found that the fraction of organics in the submicrometer SSA was higher in summer (68%) than fall (49%), and that the organic fraction in the SSA increased as the concentration of chlorophyll-a increased in seawater, suggesting that the high phytoplankton biomass in seawater could lead to the enhancement of organic species in the SSA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design of pyrolysis reactor for production of bio-oil and bio-char simultaneously

NASA Astrophysics Data System (ADS)

Aladin, Andi; Alwi, Ratna Surya; Syarif, Takdir

2017-05-01

The residues from the wood industry are the main contributors to biomass waste in Indonesia. The conventional pyrolysis process, which needs a large energy as well as to produce various toxic chemical to the environment. Therefore, a pyrolysis unit on the laboratory scale was designed that can be a good alternative to achieve zero-waste and low energy cost. In this paper attempts to discuss design and system of pyrolysis reactor to produce bio-oil and bio-char simultaneously.

Effect of pH of spray solution on the electrical properties of cadmium oxide thin films

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

Hodlur, R. M.; Gunnagol, Raghu M.; Rabinal, M. K., E-mail: mkrabinal@yahoo.com

2015-06-24

Highly conducting transparent cadmium oxide thin films were prepared by conventional spray pyrolysis technique on glass at 375 °C substrate temperature. The pH of the spray solution was varied by adding ammonia/hydrochloric acid in the spray solution. The XRD pattern showed cubic phase. A lowest resistivity of 9.9 × 10{sup −4} Ω cm (with carrier concentration (n) = 5.1 × 10{sup 20} cm{sup −3}, mobility (µ)=12.4 cm{sup 2}/Vs) is observed for pH ∼12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70 %. Thus, without any doping, the electricalmore » conductivity of CdO films could be easily tuned by simply varying the pH of spray solution without compromising the transparency and keeping the other deposition parameters fixed.« less

Development of SnS (FTO/CdS/SnS) thin films by nebulizer spray pyrolysis (NSP) for solar cell applications

NASA Astrophysics Data System (ADS)

Arulanantham, A. M. S.; Valanarasu, S.; Jeyadheepan, K.; Ganesh, V.; Shkir, Mohd

2018-01-01

Herein we report a well-organized analysis on various key-properties of SnS thin films for solar cell fabricated by nebulizer spray pyrolysis technique. X-ray diffraction study reveals the polycrystalline nature of deposited films with orthorhombic crystal structure. The crystallite size was calculated and observed to be in the range of 8-28 nm with increasing molarity of precursor solution. The stoichiometry composition of SnS was confirmed by EDX study. SEM/AFM studies divulge the well-covered deposited surface with spherical grains and the size of grains is increasing with concentration and so the roughness. A remarkable decrease in band gap from 2.6 eV to 1.6 eV was noticed by raising the molar concentration from 0.025 M up to 0.075 M. A single strong emission peak at about 825 nm is observed in PL spectra with enhanced intensity which may be attributed to near band edge emission. From the Hall effect measurement, it was found that the SnS thin film exhibits p-type conductivity. The calculated values of resistivity and carrier concentration are 0.729 Ω cm and 3.67 × 1018/cm3 respectively. Furthermore, to study the photovoltaic properties of SnS thin films a heterojunction solar cell, FTO/n-CdS/p-SnS was produced and the conversion efficiency was recorded about 0.01%.

Influence of precursor concentration on physical properties of CdO thin films prepared by spray pyrolysis technique using nebulizer

NASA Astrophysics Data System (ADS)

Anitha, M.; Amalraj, L.; Anitha, N.

2017-12-01

Cadmium oxide (CdO) thin films were prepared with different concentrations of precursor solution (0.05, 0.1, 0.15, 0.2 and 0.25 M, respectively) at the optimized temperature (200 °C) using the nebulized spray pyrolysis technique to obtain better crystallinity in polycrystalline thin films on amorphous glass substrates. The XRD characterization of those samples revealed a preferential orientation along the (111) plane having a cubic structure. The scanning electron microscopy (SEM) analysis displayed that all the as-deposited thin films have spherical shaped grains. The transmittance of the as-deposited CdO thin films had decreased from 88 to 71% for longer wavelength regions (600-900 nm) as the precursor concentration had increased and then increased for higher precursor concentration. The optical band gap was found to lie between 2.45 and 2.40 eV belonging to direct transition for those thin films. The presence of Cd-O bond (540 cm-1) was confirmed by FTIR spectrum. The emission properties of CdO thin films were studied by luminescence spectrum recorded at room temperature. A maximum carrier concentration and minimum resistivity values of 4.743 × 1019 cm- 3 and 1.06 × 10-3 Ω-cm, respectively, were obtained for 0.2 M precursor concentration. These CdO thin films have high optical transmittance and high room temperature conductivity, which can be used as the TCO and Solar cell (window layer) material.

Metal-Organic Framework Modified Glass Substrate for Analysis of Highly Volatile Chemical Warfare Agents by Paper Spray Mass Spectrometry.

PubMed

Dhummakupt, Elizabeth S; Carmany, Daniel O; Mach, Phillip M; Tovar, Trenton M; Ploskonka, Ann M; Demond, Paul S; DeCoste, Jared B; Glaros, Trevor

2018-03-07

Paper spray mass spectrometry has been shown to successfully analyze chemical warfare agent (CWA) simulants. However, due to the volatility differences between the simulants and real G-series (i.e., sarin, soman) CWAs, analysis from an untreated paper substrate proved difficult. To extend the analytical lifetime of these G-agents, metal-organic frameworks (MOFs) were successfully integrated onto the paper spray substrates to increase adsorption and desorption. In this study, several MOFs and nanoparticles were tested to extend the analytical lifetimes of sarin, soman, and cyclosarin on paper spray substrates. It was found that the addition of either UiO-66 or HKUST-1 to the paper substrate increased the analytical lifetime of the G-agents from less than 5 min detectability to at least 50 min.

Pyrolysis of automotive shredder residue in a bench scale rotary kiln.

PubMed

Notarnicola, Michele; Cornacchia, Giacinto; De Gisi, Sabino; Di Canio, Francesco; Freda, Cesare; Garzone, Pietro; Martino, Maria; Valerio, Vito; Villone, Antonio

2017-07-01

Automotive shredder residue (ASR) can create difficulties when managing, with its production increasing. It is made of different type of plastics, foams, elastomers, wood, glasses and textiles. For this reason, it is complicated to dispose of in a cost effective way, while also respecting the stringent environmental restrictions. Among thermal treatments, pyrolysis seems to offer an environmentally attractive method for the treatment of ASR; it also allows for the recovery of valuable secondary materials/fuels such as pyrolysis oils, chars, and gas. While, there is a great deal of significant research on ASR pyrolysis, the literature on higher scale pyrolysis experiments is limited. To improve current literature, the aim of the study was to investigate the pyrolysis of ASR in a bench scale rotary kiln. The Italian ASR was separated by dry-sieving into two particle size fractions: d<30mm and d>30mm. Both the streams were grounded, pelletized and then pyrolyzed in a continuous bench scale rotary kiln at 450, 550 and 650°C. The mass flow rate of the ASR pellets was 200-350g/h and each test ran for about 4-5h. The produced char, pyrolysis oil and syngas were quantified to determine product distribution. They were thoroughly analyzed with regard to their chemical and physical properties. The results show how higher temperatures increase the pyrolysis gas yield (44wt% at 650°C) as well as its heating value. The low heating value (LHV) of syngas ranges between 18 and 26MJ/Nm 3 dry. The highest pyrolysis oil yield (33wt.%) was observed at 550°C and its LHV ranges between 12.5 and 14.5MJ/kg. Furthermore, only two out of the six produced chars respect the LHV limit set by the Italian environmental regulations for landfilling. The obtained results in terms of product distribution and their chemical-physical analyses provide useful information for plant scale-up. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyrolysis of fast-growing aquatic biomass -Lemna minor (duckweed): Characterization of pyrolysis products.

PubMed

Muradov, Nazim; Fidalgo, Beatriz; Gujar, Amit C; T-Raissi, Ali

2010-11-01

The aim of this work was to conduct the experimental study of pyrolysis of fast-growing aquatic biomass -Lemna minor (commonly known as duckweed) with the emphasis on the characterization of main products of pyrolysis. The yields of pyrolysis gas, pyrolytic oil (bio-oil) and char were determined as a function of pyrolysis temperature and the sweep gas (Ar) flow rate. Thermogravimetric/differential thermogravimetric (TG/DTG) analyses of duckweed samples in inert (helium gas) and oxidative (air) atmosphere revealed differences in the TG/DTG patterns obtained for duckweed and typical plant biomass. The bio-oil samples produced by duckweed pyrolysis at different reaction conditions were analyzed using GC-MS technique. It was found that pyrolysis temperature had minor effect on the bio-oil product slate, but exerted major influence on the relative quantities of the individual pyrolysis products obtained. While, the residence time of the pyrolysis vapors had negligible effect on the yield and composition of the duckweed pyrolysis products. Copyright 2010 Elsevier Ltd. All rights reserved.

Chemical composition of Titan's aerosols analogues characterized with a systematic pyrolysis-gas chromatography-mass spectrometry characterization

NASA Astrophysics Data System (ADS)

Szopa, Cyril; Raulin, Francois; Coll, Patrice; Cabane, Michel; GCMS Team

2014-05-01

The in situ chemical characterization of Titan's atmosphere was achieved in 2005 with two instruments present onboard the Huygens atmospheric probe : the Aerosol Collector and Pyrolyzer (ACP) devoted to collect and pyrolyse Titan's aerosols ; the Gas Chromatograph-Mass Spectrometer (GCMS) experiment devoted to analyze gases collected in the atmosphere or coming from the aerosols pyrolysis. The GCMS was developed by Hasso Niemann in the filiation of the quadrupole mass spectrometers he built for several former space missions. The main objectives were to : determine the concentration profile of the most abundant chemical species; seek for minor atmospheric organic species not detected with remote observations ; give a first view of the organic aerosols structure; characterize the condensed volatiles present at the surface (e.g. lakes) in case of survival of the probe to the landing impact. Taking into account for the potential complexity of the gaseous samples to be analyzed, it was decided to couple to the MS analyzer a gas chromatograph capable to separate volatile species from light inorganic molecules and noble gases, to organic compounds including aromatics. This was the first GCMS analyzer that worked in an extraterrestrial environment since the Viking missions on Mars. Even if the GCMS coupling mode did not provide any result of interest, it has been demonstrated to be functional during the Huygens descent. But, the direct MS analysis of the atmosphere, and the pyrolysis-MS analysis of aerosols allowed to make great discoveries which are still of primary importance to describe the Titan's lower atmosphere composition. This contribution aims at presenting this instrument that worked in the Titan's atmosphere, and summarizing the most important discoveries it allowed.

Sea spray aerosol chemical composition: elemental and molecular mimics for laboratory studies of heterogeneous and multiphase reactions.

PubMed

Bertram, Timothy H; Cochran, Richard E; Grassian, Vicki H; Stone, Elizabeth A

2018-04-03

Sea spray aerosol particles (SSA), formed through wave breaking at the ocean surface, contribute to natural aerosol particle concentrations in remote regions of Earth's atmosphere, and alter the direct and indirect effects of aerosol particles on Earth's radiation budget. In addition, sea spray aerosol serves as suspended surface area that can catalyze trace gas reactions. It has been shown repeatedly that sea spray aerosol is heavily enriched in organic material compared to the surface ocean. The selective enrichment of organic material complicates the selection of representative molecular mimics of SSA for laboratory or computational studies. In this review, we first provide a short introduction to SSA formation processes and discuss chemical transformations of SSA that occur in polluted coastal regions and remote pristine air. We then focus on existing literature of the chemical composition of nascent SSA generated in controlled laboratory experiments and field investigations. We combine the evidence on the chemical properties of nascent SSA with literature measurements of SSA water uptake to assess SSA molecular composition and liquid water content. Efforts to speciate SSA organic material into molecular classes and specific molecules have led to the identification of saccharides, alkanes, free fatty acids, anionic surfactants, dicarboxylic acids, amino acids, proteinaceous matter, and other large macromolecules. However to date, less than 25% of the organic mass of nascent SSA has been quantified at a molecular level. As discussed here, quantitative measurements of size resolved elemental ratios, combined with determinations of water uptake properties, provides unique insight on the concentration of ions within SSA as a function of particle size, pointing to a controlling role for relative humidity and the hygroscopicity of SSA organic material at small particle diameters.

Oxygen production by pyrolysis of lunar regolith

NASA Technical Reports Server (NTRS)

Senior, Constance L.

1991-01-01

Oxygen was identified as the most important product of initial lunar materials processing efforts. A source of oxygen on the Moon provides an alternative to the costly transport of propellant to the Moon or to low earth orbit. Pyrolysis, or vapor-phase reduction, involves heating a feedstock to temperatures sufficient to decompose the constituent metal oxides and release oxygen. The process relies on the vaporization of metal oxides in the form of reduced suboxides or atomic species. The reduced species must then be condensed without re-oxidizing, yielding oxygen in the gas phase. The feasibility of obtaining oxygen from common lunar minerals was demonstrated using solar furnace experiments. These results are discussed together with chemical equilibrium models which were extended to include the multicomponent oxides used in experiments. For the first time, both experiments and theoretical models dealt with the complex oxides that make up potential lunar feedstocks. Two major conclusions are drawn from this preliminary work. First, unbeneficiated regolith is a suitable feedstock for pyrolysis. Second, the process can operate at moderate temperatures, circa 2000 K, which could be supplied by direct solar or electrical energy. In addition to these advantages in choice of feedstock and energy source, the pyrolysis process requires no chemicals or reagents, making it an attractive process for lunar oxygen production.

Synthesis, characterization and ellipsometric study of ultrasonically sprayed Co3O4 films

NASA Astrophysics Data System (ADS)

Gençyılmaz, O.; Taşköprü, T.; Atay, F.; Akyüz, İ.

2015-10-01

In the present study, cobalt oxide (Co3O4) films were produced using ultrasonic spray pyrolysis technique onto the glass substrate at different temperatures (200-250-300-350 °C). The effect of substrate temperature on the structural, optical, surface and electrical properties of Co3O4 films was reported. Thickness, refractive index and extinction coefficient of the films were determined by spectroscopic ellipsometry, and X-ray diffraction analyses revealed that Co3O4 films were polycrystalline fcc structure and the substrate temperature significantly improved the crystal structure of Co3O4 films. The films deposited at 350 °C substrate temperature showed the best structural quality. Transmittance, absorbance and reflectance spectra were taken by means of UV-Vis spectrophotometer, and optical band gap values were calculated using optical method. Surface images and roughness values of the films were taken by atomic force microscopy to see the effect of deposition temperature on surface properties. The resistivity of the films slightly decreases with increase in the substrate temperature from 1.08 × 104 to 1.46 × 102 Ω cm. Finally, ultrasonic spray pyrolysis technique allowed production of Co3O4 films, which are alternative metal oxide film for technological applications, at low substrate temperature.

Phosphorus transformations in plant-based and bio-waste materials induced by pyrolysis.

PubMed

Robinson, James Stephen; Baumann, Karen; Hu, Yongfeng; Hagemann, Philipp; Kebelmann, Lutz; Leinweber, Peter

2018-01-01

Strategies are needed to increase the sustainability of phosphorus (P) fertiliser management in agriculture. This paper reports on the potential of pyrolysis treatment to recycle P from renewable materials previously regarded as wastes. The study used K-edge X-ray absorption near-edge structure (XANES) spectroscopy to examine chemical forms of P in the waste feedstock materials and corresponding biochars (pyrolysis at 480-500 °C) of four ligno-cellulosic, plant-based residues and five relatively P-rich livestock and water-treatment by-products, to acquire information on changes in potential P fertiliser value. Pyrolysis enriched P in the biochars by factors of 1.3-4.3, thus offering wide-ranging P fertiliser potential. XANES spectroscopy revealed hydroxyapatite (HAP) as one of the dominant chemical P compounds in the feedstocks, ranging from 14% (rice husks) to 98% (animal bone) of total P. For most materials, pyrolysis increased the proportion of HAP, and pyrophosphates were generated in several cases. These alterations possibly lead to diversity in the P solubility characteristics of the biochars if used as soil amendments; this is an important property of environmentally sound P fertilisers.

High power density cell using nanostructured Sr-doped SmCoO3 and Sm-doped CeO2 composite powder synthesized by spray pyrolysis

NASA Astrophysics Data System (ADS)

Shimada, Hiroyuki; Yamaguchi, Toshiaki; Suzuki, Toshio; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

2016-01-01

High power density solid oxide electrochemical cells were developed using nanostructure-controlled composite powder consisting of Sr-doped SmCoO3 (SSC) and Sm-doped CeO2 (SDC) for electrode material. The SSC-SDC nano-composite powder, which was synthesized by spray pyrolysis, had a narrow particle size distribution (D10, D50, and D90 of 0.59, 0.71, and 0.94 μm, respectively), and individual particles were spherical, composing of nano-size SSC and SDC fragments (approximately 10-15 nm). The application of the powder to a cathode for an anode-supported solid oxide fuel cell (SOFC) realized extremely fine cathode microstructure and excellent cell performance. The anode-supported SOFC with the SSC-SDC cathode achieved maximum power density of 3.65, 2.44, 1.43, and 0.76 W cm-2 at 800, 750, 700, and 650 °C, respectively, using humidified H2 as fuel and air as oxidant. This result could be explained by the extended electrochemically active region in the cathode induced by controlling the structure of the starting powder at the nano-order level.

Spatial distribution visualization of PWM continuous variable-rate spray

USDA-ARS?s Scientific Manuscript database

Chemical application is a dynamic spatial distribution process, during which spray liquid covers the targets with certain thickness and uniformity. Therefore, it is important to study the 2-D and 3-D (dimensional) spray distribution to evaluate spraying quality. The curve-surface generation methods ...

Structural and Solar Cell Properties of a Ag-Containing Cu2ZnSnS4 Thin Film Derived from Spray Pyrolysis.

PubMed

Nguyen, Thi Hiep; Kawaguchi, Takato; Chantana, Jakapan; Minemoto, Takashi; Harada, Takashi; Nakanishi, Shuji; Ikeda, Shigeru

2018-02-14

A silver (Ag)-incorporated kesterite Cu 2 ZnSnS 4 (CZTS) thin film was fabricated by a facile spray pyrolysis method. Crystallographic analyses indicated successful incorporation of various amounts of Ag up to a Ag/(Ag + Cu) ratio of ca. 0.1 into the crystal lattice of CZTS in a homogeneous manner without formation of other impurity compounds. From the results of morphological investigations, Ag-incorporated films had larger crystal grains than the CZTS film. The sample with a relatively low Ag content (Ag/(Ag + Cu) of ca. 0.02) had a compact morphology without appreciable voids and pinholes. However, an increase in the Ag content in the CZTS film (Ag/(Ag + Cu) ca. 0.10) induced the formation of a large number of pinholes. As can be expected from these morphological properties, the best sunlight conversion efficiency was obtained by the solar cell based on the film with Ag/(Ag + Cu) of ca. 0.02. Electrostructural analyses of the devices suggested that the Ag-incorporated film in the device achieved reduction in the amounts of unfavorable copper on zinc antisite defects compared to the bare CZTS film. Moreover, the use of a Ag-incorporated film improved band alignment at the CdS(buffer)-CZTS interface. These alterations should also contribute to enhancement of device properties.

Gas Chromatography/Atmospheric Pressure Chemical Ionization-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of Pyrolysis Oil from German Brown Coal

PubMed Central

Zuber, Jan; Kroll, Marius M.; Rathsack, Philipp; Otto, Matthias

2016-01-01

Pyrolysis oil from the slow pyrolysis of German brown coal from Schöningen, obtained at a temperature of 500°C, was separated and analyzed using hyphenation of gas chromatography with an atmospheric pressure chemical ionization source operated in negative ion mode and Fourier transform ion cyclotron resonance mass spectrometry (GC-APCI-FT-ICR-MS). Development of this ultrahigh-resolving analysis method is described, that is, optimization of specific GC and APCI parameters and performed data processing. The advantages of GC-APCI-FT-ICR-MS hyphenation, for example, soft ionization, ultrahigh-resolving detection, and most important isomer separation, were demonstrated for the sample liquid. For instance, it was possible to separate and identify nine different propylphenol, ethylmethylphenol, and trimethylphenol isomers. Furthermore, homologous series of different acids, for example, alkyl and alkylene carboxylic acids, were verified, as well as homologous series of alkyl phenols, alkyl dihydroxy benzenes, and alkoxy alkyl phenols. PMID:27066076

Zr-doped SnO2 thin films synthesized by spray pyrolysis technique for barrier layers in solar cells

NASA Astrophysics Data System (ADS)

Reddy, N. Nanda Kumar; Akkera, Harish Sharma; Sekhar, M. Chandra; Park, Si-Hyun

2017-12-01

In the present work, we investigated the effect of Zr doping (0-6 at%) on the structural, electrical, and optical properties of tin oxide (SnO2) thin films deposited onto glass substrates using a spray pyrolysis technique. The room-temperature X-ray diffraction pattern shows that all deposited films exhibit polycrystalline tetragonal structure. The pure SnO2 film is grown along a preferred (200) direction, whereas Zr-doped SnO2 (Zr:SnO2) films started growing along the (220) orientation along with a high intensity peak of (200). Scanning electron microscope (SEM) and atomic force microscope (AFM) images showed that the grains of the films are spherical in structure, and the grain size decreased with increasing of Zr concentration. The optical transmission spectra of deposited films as a function of wavelength confirm that the average optical transmittance is > 85% for Zr:SnO2 films. The value of the optical bandgap is significantly decreased from 3.94 to 3.68 eV with increasing Zr concentration. Furthermore, the electrical measurements found that the sheet resistance ( R sh) and resistivity ( ρ) values are decreased with increasing of Zr doping. The lowest values of R sh = 6.82 Ω and ρ = 0.4 × 10- 3 Ω cm are found in 6-at% Zr-doped SnO2 film. In addition, a good efficiency value of the figure of merit ( ɸ = 3.35 × 10- 3 Ω-1) is observed in 6-at% Zr-doped SnO2 film. These outstanding properties of Zr-doped SnO2 films make them useful for several optoelectronic device applications.

Recent Advances in Analytical Pyrolysis to Investigate Organic Materials in Heritage Science.

PubMed

Degano, Ilaria; Modugno, Francesca; Bonaduce, Ilaria; Ribechini, Erika; Colombini, Maria Perla

2018-06-18

The molecular characterization of organic materials in samples from artworks and historical objects traditionally entailed qualitative and quantitative analyses by HPLC and GC. Today innovative approaches based on analytical pyrolysis enable samples to be analysed without any chemical pre-treatment. Pyrolysis, which is often considered as a screening technique, shows previously unexplored potential thanks to recent instrumental developments. Organic materials that are macromolecular in nature, or undergo polymerization upon curing and ageing can now be better investigated. Most constituents of paint layers and archaeological organic substances contain major insoluble and chemically non-hydrolysable fractions that are inaccessible to GC or HPLC. To date, molecular scientific investigations of the organic constituents of artworks and historical objects have mostly focused on the minor constituents of the sample. This review presents recent advances in the qualitative and semi-quantitative analyses of organic materials in heritage objects based on analytical pyrolysis coupled with mass spectrometry. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acanthocephalan fish parasites (Rhadinorhynchidae Lühe, 1912) as potential biomarkers: Molecular-chemical screening by pyrolysis-field ionization mass spectrometry

NASA Astrophysics Data System (ADS)

Kleinertz, S.; Eckhardt, K.-U.; Theisen, S.; Palm, H. W.; Leinweber, P.

2016-07-01

The present study represents the first molecular-chemical screening by pyrolysis-field ionization mass spectrometry applied on fish parasites. A total of 71 fishes from Balinese fish markets, 36 Auxis rochei (Risso, 1810) and 35 A. thazard (Lacepède, 1800), were studied for their acanthocephalan parasites. This is the first record of Rhadinorhynchus zhukovi in Balinese waters, Indonesia, and we describe for the first time A. rochei and A. thazard as R. zhukovi hosts. Using this method, small scale variations within the chemical compounds of acanthocephalans could be detected. Using this methodology it will be possible to generate additional, pollutant specific information from aquatic habitats in future with the potential of a new bioindicator application for parasite/host origin and/or environmental pollution.

Effect of Zn/Sn molar ratio on the microstructural and optical properties of Cu2Zn1-xSnxS4 thin films prepared by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Thiruvenkadam, S.; Prabhakaran, S.; Sujay Chakravarty; Ganesan, V.; Vasant Sathe; Santhosh Kumar, M. C.; Leo Rajesh, A.

2018-03-01

Quaternary kesterite Cu2ZnSnS4 (CZTS) compound is one of the most promising semiconductor materials consisting of abundant and eco-friendly elements for absorption layer in thin film solar cells. The effect of Zn/Sn ratio on Cu2Zn1-xSnxS4 (0 ≤ x ≤ 1) thin films were studied by deposited by varying molar volumes in the precursor solution of zinc and tin was carried out in proportion of (1-x) and x respectively onto soda lime glass substrates kept at 573 K by using chemical spray pyrolysis technique. The GIXRD pattern revealed that the films having composites of Cu2ZnSnS4, Cu2SnS3, Sn2S3, CuS and ZnS phases. The crystallinity and grain size were found to increase by increasing the x value and the preferential orientation along (103), (112), (108) and (111) direction corresponding to CZTS, Cu2SnS3, CuS, and ZnS phases respectively. Micro-Raman spectra exposed a prominent peak at 332 cm-1 corresponding to the CZTS phase. Atomic force microscopy was employed to study the grain size and roughness of the deposited thin films. The optical band gap was found to lie between 1.45 and 2.25 eV and average optical absorption coefficient was found to be greater than 105 cm-1. Hall measurements exhibited that all the deposited Cu2Zn1-xSnxS4 films were p type and the resistivity lies between 10.9 ×10-2Ωcm and 149.6 × 10-2Ωcm .

Prospects of pyrolysis oil from plastic waste as fuel for diesel engines: A review

NASA Astrophysics Data System (ADS)

Mangesh, V. L.; Padmanabhan, S.; Ganesan, S.; PrabhudevRahul, D.; Reddy, T. Dinesh Kumar

2017-05-01

The purpose ofthis study is to review the existing literature about chemical recycling of plastic waste and its potential as fuel for diesel engines. This is a review covering on the field of converting waste plastics into liquid hydrocarbon fuels for diesel engines. Disposal and recycling of waste plastics have become an incremental problem and environmental threat with increasing demand for plastics. One of the effective measures is by converting waste plastic into combustible hydrocarbon liquid as an alternative fuel for running diesel engines. Continued research efforts have been taken by researchers to convert waste plastic in to combustible pyrolysis oil as alternate fuel for diesel engines. An existing literature focuses on the study of chemical structure of the waste plastic pyrolysis compared with diesel oil. Converting waste plastics into fuel oil by different catalysts in catalytic pyrolysis process also reviewed in this paper. The methodology with subsequent hydro treating and hydrocracking of waste plastic pyrolysis oil can reduce unsaturated hydrocarbon bonds which would improve the combustion performance in diesel engines as an alternate fuel.

Production and characterization of chars from cherry pulp via pyrolysis.

PubMed

Pehlivan, E; Özbay, N; Yargıç, A S; Şahin, R Z

2017-12-01

Pyrolysis is an eco-friendly process to achieve valuable products like bio-oil, char and gases. In the last decades, biochar production from pyrolysis of a wide variety of industrial and agricultural wastes become popular, which can be utilized as adsorbent instead of the expensive activated carbons. In this study, cherry pulp was pyrolyzed in a fixed bed tubular reactor at five different temperatures (400, 500,550, 600 and 700 °C) and three different heating rates (10, 100 and 200 °C/min) to obtain biochar. Proximate, ultimate, nitrogen adsorption/desorption isotherms, scanning electron microscopy, thermogravimetric analysis, x-ray fluorescence, x-ray diffraction, and Fourier transform infrared spectroscopy were performed on cherry pulp and its chars to examine the chemical alterations after the pyrolysis process. Biochar yields were decreased with increasing pyrolysis temperature and heating rate, based on experimental results. Porous biochars are carbon rich and includes high potassium content. The aromaticity of biochars increased and O/C mass ratio reduced with an increase in the pyrolysis temperature as a result of the development of compact aromatic structure in char. Pyrolysis provides a promising conversion procedure for the production of high energy density char which has promising applications in existing coal-fired boilers without any upgrading. Copyright © 2017 Elsevier Ltd. All rights reserved.

Co-pyrolysis of rice straw and Polyethylene Terephthalate (PET) using a fixed bed drop type pyrolyzer

NASA Astrophysics Data System (ADS)

Izzatie, N. I.; Basha, M. H.; Uemura, Y.; Hashim, M. S. M.; Amin, N. A. M.; Hamid, M. F.

2017-10-01

In this work, co-pyrolysis of rice straw and polyethylene terephthalate (PET) was carried out at different temperatures (450,500,550, and 600°C) at ratio 1:1 by using fixed bed drop-type pyrolyzer. The purpose of this work is to determine the effect of pyrolysis temperature on the product yield. As the temperature increased, the pyrolysis oil increased until it reaches certain high temperature (600°C), the pyrolysis oil decreased as of more NCG were produced. The temperature 550°C is considered as the optimum pyrolysis temperature since it produced the highest amount of pyrolysis oil with 36 wt.%. In pyrolysis oil, the calorific value (13.98kJ/g) was low because of the presence of high water content (52.46 wt.%). Main chemicals group from pyrolysis oil were an aldehyde, ketones, acids, aromatics, and phenol and all compound have abundant of hydrogen and carbon were identified. Co-pyrolysis of rice straw and PET produced a higher amount of carbon oxides and recycling back the NCG could increase liquid and char yields.

Effects of the precursor concentration and different annealing ambients on the structural, optical, and electrical properties of nanostructured V2O5 thin films deposited by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Irani, Rowshanak; Rozati, Seyed Mohammad; Beke, Szabolcs

2018-04-01

V2O5 thin films were deposited with different precursor concentrations of 0.01, 0.05, and 0.1 M on glass substrates by spray pyrolysis technique, then the optimized films were annealed in different ambients (air, oxygen, and vacuum). The results showed that by increasing the concentration, the films grew along the (001) direction with an orthorhombic structure. Field emission scanning electron microscopy showed that nanorods were formed when depositing 0.05 molar of VCl3. We conclude that with the precursor concentration, the surface nanostructure can be well-controlled. Annealing improved the crystallinity under all ambients, but the best crystallinity was achieved in vacuum. It was revealed that the as-deposited films had the highest transmission, whereas the films annealed in air had the lowest. When annealed in air, the optical band gap decreased from 2.45 to 2.32 eV. The sheet resistance, resistivity, mobility, conductivity, and carrier concentration were measured for all the prepared V2O5 films.

Influence of substrate temperature on structural, morphological, optical and electrical properties of Bi-doped MnInS4 thin films prepared by nebuliser spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Kennedy, A.; Senthil Kumar, V.; Pradeev Raj, K.

2017-11-01

Bismuth (Bi)-doped manganese indium sulphide (MnInS4) thin films were deposited on heated glass substrates using an aqueous solution of MnCl2, InCl3, (NH2)2CS and BiCl3 by the common nebuliser spray pyrolysis technique. The thin films were grown at various substrate temperatures ranging from 250 to 400 °C with a constant spray time (5 min). The present work aims to study the effect of substrate temperature on the structural, optical, photoluminescence and electrical properties of the grown thin films using various techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectrum (EDS), UV-Vis absorption spectroscopy, photoluminescence spectra (PL) and four probe methods. The XRD pattern reveals that the Bi-doped MnInS4 thin films were polycrystalline in nature with a cubic spinel structure whose particle size varies between 8.2 and 23.5 nm. From the FE-SEM micrographs, due to the change in the substrate temperature, shapes such as spherical, needle-shaped and T-shaped grains were observed throughout the surface of the films. The energy dispersive analysis spectrum (EDS) shows the presence of Mn, In, S and Bi in the film grown at 250 °C. It is interesting to note that the structural homogeneity and crystallinity of the film is improved due to the decrease in the absorption coefficient (α) and extinction coefficient (K) with an increase in substrate temperature. Also, with an increase in the substrate temperature, the calculated band gap energy was found to decrease from 1.87 to 1.59 eV. From the PL spectra, several intense peaks corresponding to blue, green, yellow, orange and red band emissions were observed in the wavelength region of 350-650 nm. Moreover as the intensity of the peak increases with increase in the substrate temperature, the crystallinity of the material of the film greatly improves concomitant with minimum strain and defect states. From the electrical studies, the electrical conductivity

Catalytic and non-catalytic pyrolysis of biomass in non-inert environments for production of deoxygenated bio-oil and chemicals

USDA-ARS?s Scientific Manuscript database

Fast pyrolysis processes are among the most effective methods for liquefaction of lignocellulosic biomass. Catalytic fast pyrolysis (CFP) over HZSM-5 or other zeolites and/or utilization of reactive atmospheres such as in the non-catalytic Tail Gas Reactive Pyrolysis (TRGP) process, a recent patent...

A review of the toxicity of biomass pyrolysis liquids formed at low temperatures

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

Diebold, J P

1997-04-01

The scaleup of biomass fast pyrolysis systems to large pilot and commercial scales will expose an increasingly large number of personnel to potential health hazards, especially during the evaluation of the commercial use of the pyrolysis condensates. Although the concept of fast pyrolysis to optimize liquid products is relatively new, low-temperature pyrolysis processes have been used over the aeons to produce charcoal and liquid by-products, e.g., smoky food flavors, food preservatives, and aerosols containing narcotics, e.g., nicotine. There are a number of studies in the historical literature that concern the hazards of acute and long-term exposure to smoke and tomore » the historical pyrolysis liquids formed at low temperatures. The reported toxicity of smoke, smoke food flavors, and fast pyrolysis oils is reviewed. The data found for these complex mixtures suggest that the toxicity may be less than that of the individual components. It is speculated that there may be chemical reactions that take place that serve to reduce the toxicity during aging. 81 refs.« less

Microwave-assisted pyrolysis of Mississippi coal: A comparative study with conventional pyrolysis

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

Abdelsayed, Victor; Shekhawat, Dushyant; Smith, Mark W.

Pyrolysis conditions greatly affect the structure-reactivity relationship of char during coal gasification. Here, this work investigated the effect of temperature and microwave heating on the structural properties of the chars generated during pyrolysis, as well as gaseous and tar products. Results showed that microwave pyrolysis of Mississippi coal produced more gaseous products and less tars compared to conventional pyrolysis. Higher CO/CO 2 ratio (>1) was observed under microwave pyrolysis compared to conventional pyrolysis (CO/CO2 < 1), which may be explained by a greater extent of gasification between solid carbon and the CO 2 formed during microwave pyrolysis. Additionally, in microwavemore » pyrolysis, the oil tars generated exhibited lower concentrations of polar oxygenates, while the wax tars showed higher concentrations of non-polar alkanes, as observed from the intensity of CH vibrations in FTIR. The product compositions and FTIR analysis of the tars (oils and waxes) suggest that the microwave interacted preferentially with these polar species, which have relatively higher dielectric properties compared to alkanes. The structure–reactivity relationship of the chars produced was also investigated using a variety of characterization tools such as XRD, BET, SEM, EDS, and FTIR. Finally, the char reactivity towards combustion suggested that microwave-produced chars have a higher thermal stability, likely due to lower O/C ratios, and could be utilized in the metallurgical industry.« less

Microwave-assisted pyrolysis of Mississippi coal: A comparative study with conventional pyrolysis

DOE PAGES

Abdelsayed, Victor; Shekhawat, Dushyant; Smith, Mark W.; ...

2018-01-13

Pyrolysis conditions greatly affect the structure-reactivity relationship of char during coal gasification. Here, this work investigated the effect of temperature and microwave heating on the structural properties of the chars generated during pyrolysis, as well as gaseous and tar products. Results showed that microwave pyrolysis of Mississippi coal produced more gaseous products and less tars compared to conventional pyrolysis. Higher CO/CO 2 ratio (>1) was observed under microwave pyrolysis compared to conventional pyrolysis (CO/CO2 < 1), which may be explained by a greater extent of gasification between solid carbon and the CO 2 formed during microwave pyrolysis. Additionally, in microwavemore » pyrolysis, the oil tars generated exhibited lower concentrations of polar oxygenates, while the wax tars showed higher concentrations of non-polar alkanes, as observed from the intensity of CH vibrations in FTIR. The product compositions and FTIR analysis of the tars (oils and waxes) suggest that the microwave interacted preferentially with these polar species, which have relatively higher dielectric properties compared to alkanes. The structure–reactivity relationship of the chars produced was also investigated using a variety of characterization tools such as XRD, BET, SEM, EDS, and FTIR. Finally, the char reactivity towards combustion suggested that microwave-produced chars have a higher thermal stability, likely due to lower O/C ratios, and could be utilized in the metallurgical industry.« less

Leaf spray: direct chemical analysis of plant material and living plants by mass spectrometry.

PubMed

Liu, Jiangjiang; Wang, He; Cooks, R Graham; Ouyang, Zheng

2011-10-15

The chemical constituents of intact plant material, including living plants, are examined by a simple spray method that provides real-time information on sugars, amino acids, fatty acids, lipids, and alkaloids. The experiment is applicable to various plant parts and is demonstrated for a wide variety of species. An electrical potential is applied to the plant and its natural sap, or an applied solvent generates an electrospray that carries endogenous chemicals into an adjacent benchtop or miniature mass spectrometer. The sharp tip needed to create a high electric field can be either natural (e.g., bean sprout) or a small nick can be cut in a leaf, fruit, bark, etc. Stress-induced changes in glucosinolates can be followed on the minute time scale in several plants, including potted vegetables. Differences in spatial distributions and the possibility of studying plant metabolism are demonstrated. © 2011 American Chemical Society

Rapid detection of bacteria with miniaturized pyrolysis-gas chromatographic analysis

NASA Astrophysics Data System (ADS)

Mowry, Curtis; Morgan, Catherine H.; Baca, Quentin; Manginell, Ronald P.; Kottenstette, Richard J.; Lewis, Patrick; Frye-Mason, Gregory C.

2002-02-01

Rapid detection and identification of bacteria and other pathogens is important for many civilian and military applications. The profiles of biological markers such as fatty acids can be used to characterize biological samples or to distinguish bacteria at the gram-type, genera, and even species level. Common methods for whole cell bacterial analysis are neither portable nor rapid, requiring lengthy, labor intensive sample preparation and bench-scale instrumentation. These methods chemically derivatize fatty acids to produce more volatile fatty acid methyl esters (FAMEs) that can be separated and analyzed by a gas chromatograph (GC)/mass spectrometer. More recent publications demonstrate decreased sample preparation time with in situ derivatization of whole bacterial samples using pyrolysis/derivatization. Ongoing development of miniaturized pyrolysis/GC instrumentation by this department capitalizes on Sandia advances in the field of microfabricated chemical analysis systems ((mu) ChemLab). Microdevices include rapidly heated stages capable of pyrolysis or sample concentration, gas chromatography columns, and surface acoustic wave (SAW) sensor arrays. We will present results demonstrating the capabilities of these devices toward fulfilling the goal of portable, rapid detection and early warning of the presence of pathogens in air or water.

Oxidative and inert pyrolysis on-line coupled to gas chromatography with mass spectrometric detection: On the pyrolysis products of tobacco additives.

PubMed

Paschke, Meike; Hutzler, Christoph; Henkler, Frank; Luch, Andreas

2016-11-01

According to European legislation, tobacco additives may not increase the toxicity or the addictive potency of the product, but there is an ongoing debate on how to reliably characterize and measure such properties. Further, too little is known on pyrolysis patterns of tobacco additives to assume that no additional toxicological risks need to be suspected. An on-line pyrolysis technique was used and coupled to gas chromatography-mass spectrometry (GC/MS) to identify the pattern of chemical species formed upon thermal decomposition of 19 different tobacco additives like raw cane sugar, licorice or cocoa. To simulate the combustion of a cigarette it was necessary to perform pyrolysis at inert conditions as well as under oxygen supply. All individual additives were pyrolyzed under inert or oxidative conditions at 350, 700 and 1000°C, respectively, and the formation of different toxicants was monitored. We observed the generation of vinyl acrylate, fumaronitrile, methacrylic anhydride, isobutyric anhydride and 3-buten-2-ol exclusively during pyrolysis of tobacco additives. According to the literature, these toxicants so far remained undetectable in tobacco or tobacco smoke. Further, the formation of 20 selected polycyclic aromatic hydrocarbons (PAHs) with molecular weights of up to 278Da was monitored during pyrolysis of cocoa in a semi-quantitative approach. It was shown that the adding of cocoa to tobacco had no influence on the relative amounts of the PAHs formed. Copyright © 2016 Elsevier GmbH. All rights reserved.

Properties of CuInS₂ Nano-Particles on TiO₂ by Spray Pyrolysis for CuInS₂/TiO₂ Composite Solar Cell.

PubMed

Park, Gye-Choon; Li, Zhen-Yu; Yang, O-Bong

2017-04-01

In this letter, for the absorption layer of a CuInS₂/TiO₂ composite solar cell, I–III–VI2 chalcopyrite semiconductor CuInS₂ nano-particles were deposited by using spray pyrolysis method on TiO2 porous film. Their material characteristics including structural and optical properties of CuInS₂ nano-particles on TiO₂ nanorods were analyzed as a function of its composition ratios of Cu:In:S. Crystalline structure, surface morphology and crystalline size were also investigated by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and High-Resolution TEM (HRTEM), respectively. On the other hand, optical property was characterized by an UV-Visible Spectrophotometer. As a result, it was found that the size of CuInS₂ nano-particles, which was formed at 300±5 °C, was smaller than 16 nm from HRTEM analyses, and it was identified that the CuInS₂ particle size was increased as increasing the heat-treatment temperature and time. However, as the size of CuInS₂ nano-particle becomes smaller, optical absorption edge of ternary compound film tends to move to the blue wavelength band. It turns out that the optical energy-band gap of the compound films was ranging from 1.48 eV to 1.53 eV.

Biofuel from jute stick by pyrolysis technology

NASA Astrophysics Data System (ADS)

Ferdous, J.; Parveen, M.; Islam, M. R.; Haniu, H.; Takai, K.

2017-06-01

In this study the conversion of jute stick into biofuels and chemicals by externally heated fixed-bed pyrolysis reactor have been taken into consideration. The solid jute stick was characterized through proximate and ultimate analysis, gross calorific values and thermo-gravimetric analysis to investigate their suitability as feedstock for this consideration. The solid biomass particles were fed into the reactor by gravity feed type reactor feeder. The products were oil, char and gases. The liquid and char products were collected separately while the gas was flared into the atmosphere. The process conditions were varied by fixed-bed temperature; feed stock particle size, N2 gas flow rate and running time. All parameters were found to influence the product yields significantly. The maximum liquid yields were 50 wt% of solid jute stick at reactor temperature 425°C for N2 gas flow rate 6 l/min, feed particle size 1180-1700 µm and running time 30 min. Liquid products obtained at these conditions were characterized by physical properties, chemical analysis and GC-MS techniques. The results show that it is possible to obtained liquid products that are comparable to petroleum fuels and valuable chemical feedstock from the selected biomass if the pyrolysis conditions are chosen accordingly.

Influence of mineral matter on pyrolysis of palm oil wastes

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

Yang, Haiping; Chen, Hanping; Zheng, Chuguang

2006-09-15

The influence of mineral matter on pyrolysis of biomass (including pure biomass components, synthesized biomass, and natural biomass) was investigated using a thermogravimetric analyzer (TGA). First, the mineral matter, KCl, K{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, CaMg(CO{sub 3}){sub 2}, Fe{sub 2}O{sub 3}, and Al{sub 2}O{sub 3}, was mixed respectively with the three main biomass components (hemicellulose, cellulose, and lignin) at a weight ratio (C/W) of 0.1 and its pyrolysis characteristics were investigated. Most of these mineral additives, except for K{sub 2}CO{sub 3}, demonstrated negligible influence. Adding K{sub 2}CO{sub 3} inhibited the pyrolysis of hemicellulose by lowering its mass loss ratemore » by 0.3 wt%/{sup o}C, while it enhanced the pyrolysis of cellulose by shifting the pyrolysis to a lower temperature. With increased K{sub 2}CO{sub 3} added, the weight loss of cellulose in the lower temperature zone (200-315 {sup o}C) increased greatly, and the activation energies of hemicellulose and cellulose pyrolysis decreased notably from 204 to 42 kJ/mol. Second, studies on the synthetic biomass of hemicellulose, cellulose, lignin, and K{sub 2}CO{sub 3} (as a representative of minerals) indicated that peaks of cellulose and hemicellulose pyrolysis became overlapped with addition of K{sub 2}CO{sub 3} (at C/W=0.05-0.1), due to the catalytic effect of K{sub 2}CO{sub 3} lowering cellulose pyrolysis to a lower temperature. Finally, a local representative biomass--palm oil waste (in the forms of original material and material pretreated through water washing or K{sub 2}CO{sub 3} addition)--was studied. Water washing shifted pyrolysis of palm oil waste to a higher temperature by 20 {sup o}C, while K{sub 2}CO{sub 3} addition lowered the peak temperature of pyrolysis by {approx}50{sup o}C. It was therefore concluded that the obvious catalytic effect of adding K{sub 2}CO{sub 3} might be attributed to certain fundamental changes in terms of chemical structure of

Spray nozzle designs for agricultural aviation applications. [relation of drop size to spray characteristics and nozzle efficiency

NASA Technical Reports Server (NTRS)

Lee, K. W.; Putnam, A. A.; Gieseke, J. A.; Golovin, M. N.; Hale, J. A.

1979-01-01

Techniques of generating monodisperse sprays and information concerning chemical liquids used in agricultural aviation are surveyed. The periodic dispersion of liquid jet, the spinning disk method, and ultrasonic atomization are the techniques discussed. Conceptually designed spray nozzles for generating monodisperse sprays are assessed. These are based on the classification of the drops using centrifugal force, on using two opposing liquid laden air jets, and on operating a spinning disk at an overloaded flow. Performance requirements for the designs are described and estimates of the operational characteristics are presented.

Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis

NASA Technical Reports Server (NTRS)

Leif, Roald N.; Simoneit, Bernd R. T.

1995-01-01

A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

DOEpatents

Chum, H.L.; Evans, R.J.

1992-08-04

A process is described for using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent. 11 figs.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

DOEpatents

Chum, Helena L.; Evans, Robert J.

1992-01-01

A process of using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent.

Predicting properties of gas and solid streams by intrinsic kinetics of fast pyrolysis of wood

DOE PAGES

Klinger, Jordan; Bar-Ziv, Ezra; Shonnard, David; ...

2015-12-12

Pyrolysis has the potential to create a biocrude oil from biomass sources that can be used as fuel or as feedstock for subsequent upgrading to hydrocarbon fuels or other chemicals. The product distribution/composition, however, is linked to the biomass source. This work investigates the products formed from pyrolysis of woody biomass with a previously developed chemical kinetics model. Different woody feedstocks reported in prior literature are placed on a common basis (moisture, ash, fixed carbon free) and normalized by initial elemental composition through ultimate analysis. Observed product distributions over the full devolatilization range are explored, reconstructed by the model, andmore » verified with independent experimental data collected with a microwave-assisted pyrolysis system. These trends include production of permanent gas (CO, CO 2), char, and condensable (oil, water) species. Elementary compositions of these streams are also investigated. As a result, close agreement between literature data, model predictions, and independent experimental data indicate that the proposed model/method is able to predict the ideal distribution from fast pyrolysis given reaction temperature, residence time, and feedstock composition.« less

Pyrolysis behavior of different type of materials contained in the rejects of packaging waste sorting plants.

PubMed

Adrados, A; De Marco, I; Lopez-Urionabarrenechea, A; Caballero, B M; Laresgoiti, M F

2013-01-01

In this paper rejected streams coming from a waste packaging material recovery facility have been characterized and separated into families of products of similar nature in order to determine the influence of different types of ingredients in the products obtained in the pyrolysis process. The pyrolysis experiments have been carried out in a non-stirred batch 3.5 dm(3) reactor, swept with 1 L min(-1) N(2), at 500°C for 30 min. Pyrolysis liquids are composed of an organic phase and an aqueous phase. The aqueous phase is greater as higher is the cellulosic material content in the sample. The organic phase contains valuable chemicals as styrene, ethylbenzene and toluene, and has high heating value (HHV) (33-40 MJ kg(-1)). Therefore they could be used as alternative fuels for heat and power generation and as a source of valuable chemicals. Pyrolysis gases are mainly composed of hydrocarbons but contain high amounts of CO and CO(2); their HHV is in the range of 18-46 MJ kg(-1). The amount of COCO(2) increases, and consequently HHV decreases as higher is the cellulosic content of the waste. Pyrolysis solids are mainly composed of inorganics and char formed in the process. The cellulosic materials lower the quality of the pyrolysis liquids and gases, and increase the production of char. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chemical and ecotoxicological characterization of solid residues produced during the co-pyrolysis of plastics and pine biomass.

PubMed

Bernardo, Maria S; Lapa, N; Barbosa, R; Gonçalves, M; Mendes, B; Pinto, F; Gulyurtlu, I

2009-07-15

A mixture of 70% (w/w) pine biomass and 30% (w/w) plastics (mixture of polypropylene, polyethylene, and polystyrene) was subjected to pyrolysis at 400 degrees C, for 15 min, with an initial pressure of 40 MPa. Part of the solid residue produced was subjected to extraction with dichloromethane (DCM). The extracted residue (residue A) and raw residue (residue B) were analyzed by weight loss combustion and submitted to the leaching test ISO/TS 21268-2 using two different leachants: DCM (0.2%, v/v) and calcium chloride (0.001 mol/L). The concentrations of the heavy metals Cd, Cr, Ni, Zn, Pb and Cu were determined in the eluates and in the two residues. The eluates were further characterized by determining their pH and the concentrations of benzene, toluene, ethylbenzene and xylenes (BTEX). The presence of other organic contaminants in the eluates was qualitatively evaluated by gas chromatography, coupled with mass spectrometry. An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Ecotoxicity (CEMWE). Residue A was not considered to be ecotoxic by the ecotoxicological criterion (EC(50) (30 min) >or=10%), but it was considered to be ecotoxic by the chemical criterion (Ni>or=0.5mg/L). Residue B was considered to be ecotoxic by the ecotoxicological criterion: EC(50) (30 min)pyrolysis residue with DCM was an efficient method for removing lighter organic contaminants.

Synthesis and characterization of nanosized calcium phosphates by flame spray pyrolysis, and their effect on osteogenic differentiation of stem cells

NASA Astrophysics Data System (ADS)

Ataol, Sibel; Tezcaner, Ayşen; Duygulu, Ozgur; Keskin, Dilek; Machin, Nesrin E.

2015-02-01

The present study evaluates the synthesis of biocompatible osteoconductive and osteoinductive nano calcium phosphate (CaP) particles by industrially applied, aerosol-derived flame spray pyrolysis method for biomedical field. Calcium phosphate nanoparticles were produced in a range of calcium-to-phosphorus ratio, (1.20-2.19) in order to analyze the morphology and crystallinity changes, and to test the bioactivity of particles. The characterization results confirmed that nanometer-sized, spherical calcium phosphate particles were produced. The average primary particle size was determined as 23 nm by counting more than 500 particles in TEM pictures. XRD patterns, HRTEM, SAED, and SEM analyses revealed the amorphous nature of the as-prepared nano calcium phosphate particles at low Ca/P ratios. Increases in the specific surface area and crystallinity were observed with the increasing Ca/P ratio. TGA-DTA analysis showed that the thermally stable crystal phases formed after 700 °C. Cell culture studies were conducted with urine-derived stem cells that possess the characteristics of mesenchymal stem cells. Synthesized amorphous nanoparticles did not have cytotoxic effect at 5-50 μg/ml concentration range. Cells treated with the as-prepared nanoparticles had higher alkaline phosphatase (ALP) enzyme activity than control cells, indicating osteogenic differentiation of cells. A slight decrease in ALP activity of cells treated with two highest Ca:P ratios at 50 μg/ml concentration was observed at day 7. The findings suggest that calcium phosphate nanoparticles produced in this work have a potential to be used as biomaterials in biomedical applications.

Learning Numeracy on the Job: A Case Study of Chemical Handling and Spraying. An Adult Literacy National Project Report

ERIC Educational Resources Information Center

FitzSimons, Gail; Mlcek, Susan; Hull, Oksana; Wright, Claire

2005-01-01

Ensuring that people have the appropriate level of numeracy skills is particularly important in jobs which involve a risk to public safety and the environment. This research investigates the job-related numeracy requirements in the chemical spraying and handling operations of the horticulture, local government, outdoor recreation and warehousing…

Structural, electrical and optical properties of Al-Sn codoped ZnO transparent conducting layer deposited by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Bedia, A.; Bedia, F. Z.; Aillerie, M.; Maloufi, N.

2017-11-01

Low cost Al-Sn codoped ZnO (ATZO) Transparent Conductive Oxide films were deposited by spray pyrolysis on glass substrate. The influence of Al-Sn codoping on the structural, optical and electrical properties of ZnO thin films was studied by comparing the same properties obtained in undoped ZnO, Al doped ZnO (AZO) and Sn doped ZnO (TZO) thin films. The so-obtained films crystallized in hexagonal wurtzite structure. The morphology and structural defects have been investigated by both High resolution Field Effect Scanning Electron Microscopy (FE-SEM) and Raman spectroscopy at 532 nm excitation source. In the visible region, the undoped and doped films show an average transmittance of the order of 85%, while for ATZO thin film, it is of the order of 72%, which points out a degradation of the optical properties due to the co-doping. The optical band gap of ATZO thin film achieves 3.31eV and this shift, compared to the referred samples is attributed to the Burstein-Moss (BM) and band gap narrowing (BGN) opposite effects which is due to the increase of the carrier concentration in degenerate semiconductors. Within all the samples, the ATZO thin film exhibits the lowest electrical resistivity of 4.56 × 10-3 Ωcm with a Hall mobility equal to 2.13 cm2 V-1s-1, and the highest carrier concentration of 6.41 × 1020 cm-3. The performance of ATZO transparent conductive oxide film are determined by its figure of merit (φTC), found equal to 1.69 10-4 Ω-1, which is a suitable value for potentially high-performance solar cell applications.

Chemical and mineralogical evaluation of slag products derived from the pyrolysis/melting treatment of MSW.

PubMed

Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Motomura, Yoshinobu; Watanabe, Koichiro

2006-01-01

This paper provides the results of studies on the characteristics of novel material derived from pyrolysis/melting treatment of municipal solid waste in Japan. Slag products from pyrolysis/melting plants were sampled for the purpose of detailed phase analysis and characterization of heavy metal-containing phases using optical microscopy, electron probe microanalysis (EPMA), XRF and XRD. The study revealed that the slag material contains glass (over 95%), oxide and silicate minerals (spinel, melilite, pseudowollastonite), as well as individual metallic inclusions as the major constituents. A distinct chemical diversity was discovered in the interstitial glass in terms of silica content defined as low and high silica glass end members. Elevated concentrations of Zn, Cr, Cu, Pb and Ba were recorded in the bulk composition. Cu, Pb and Ba behave as incompatible elements since they have been markedly characterized as part of polymetallic alloys and insignificantly sulfides in the form of spherical metallic inclusions associated with tracer amounts of other elements such as Sb, Sn, Ni, Zn, Al, P and Si. In contrast, an appreciable amount of Zn is retained by zinc-rich end members of spinel and partially by melilite and silica glass. Chromium exhibits similar behavior, and is considerably held by Cr-rich spinel. The intense incorporation of Zn and Cr into spinel indicates the very effective enrichment of these two elements into phases more environmentally resistant than glass. There was no evidence, however, that Cu and Pb enter into the structure of the crystalline silicates or oxides that may lead to their easier leachability upon exposure to the environment.

Effect of dry torrefaction on kinetics of catalytic pyrolysis of sugarcane bagasse

NASA Astrophysics Data System (ADS)

Daniyanto, Sutijan, Deendarlianto, Budiman, Arief

2015-12-01

Decreasing world reserve of fossil resources (i.e. petroleum oil, coal and natural gas) encourage discovery of renewable resources as subtitute for fossil resources. Biomass is one of the main natural renewable resources which is promising resource as alternate resources to meet the world's energy needs and raw material to produce chemical platform. Conversion of biomass, as source of energy, fuel and biochemical, is conducted using thermochemical process such as pyrolysis-gasification process. Pyrolysis step is an important step in the mechanism of pyrolysis - gasification of biomass. The objective of this study is to obtain the kinetic reaction of catalytic pyrolysis of dry torrified sugarcane bagasse which used Ca and Mg as catalysts. The model of kinetic reaction is interpreted using model n-order of single reaction equation of biomass. Rate of catalytic pyrolysis reaction depends on the weight of converted biomass into char and volatile matters. Based on TG/DTA analysis, rate of pyrolysis reaction is influenced by the composition of biomass (i.e. hemicellulose, cellulose and lignin) and inorganic component especially alkali and alkaline earth metallic (AAEM). From this study, it has found two equations rate of reaction of catalytic pyrolysis in sugarcane bagasse using catalysts Ca and Mg. First equation is equation of pyrolysis reaction in rapid zone of decomposition and the second equation is slow zone of decomposition. Value of order reaction for rapid decomposition is n > 1 and for slow decomposition is n<1. Constant and order of reactions for catalytic pyrolysis of dry-torrified sugarcane bagasse with presence of Ca tend to higher than that's of presence of Mg.

Thickness dependent optical properties of PEMA and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films deposited by spray pyrolysis technique on ITO substrate

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

Thakur, Anjna, E-mail: anjna56@gmail.com; Thakur, Priya; Yadav, Kamlesh, E-mail: kamlesh.yadav001@gmail.com

2016-05-06

In this paper, poly (ethyl methacrylate) (PEMA) and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films for 2, 3, 4 and 5 minutes have been deposited by spray pyrolysis technique on indium tin oxide (ITO) coated substrate. The effect of thickness of the film on the morphological and optical properties of PEMA and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films are studied. The morphological and optical properties of pure PEMA and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films are compared. The field emission scanning electron microscopy (FESEM) shows that as the thickness of film increases, uniformity of films increases. It is found from UV-Visible spectra that themore » energy band gap decreases with increasing the deposition time and refractive index increases with increasing the thickness of the film. The band gap of the nanocomposites is found less than the pure polymer film and opposite trend is observed for refractive index. The optical absorption of PEMA/ZnO nanocomposite films is higher than pure PEMA film. The thickness of the nanocomposite film plays a significant role in the tunability of the optical properties.« less

Bio-oils from biomass slow pyrolysis: a chemical and toxicological screening.

PubMed

Cordella, Mauro; Torri, Cristian; Adamiano, Alessio; Fabbri, Daniele; Barontini, Federica; Cozzani, Valerio

2012-09-15

Bio-oils were produced from bench-scale slow-pyrolysis of three different biomass samples (corn stalks, poplar and switchgrass). Experimental protocols were developed and applied in order to screen their chemical composition. Several hazardous compounds were detected in the bio-oil samples analysed, including phenols, furans and polycyclic aromatic hydrocarbons. A procedure was outlined and applied to the assessment of toxicological and carcinogenic hazards of the bio-oils. The following hazardous properties were considered: acute toxicity; ecotoxicity; chronic toxicity; carcinogenicity. Parameters related to these properties were quantified for each component identified in the bio-oils and overall values were estimated for the bio-oils. The hazard screening carried out for the three bio-oils considered suggested that: (i) hazards to human health could be associated with chronic exposures to the bio-oils; (ii) acute toxic effects on humans and eco-toxic effects on aquatic ecosystems could also be possible in the case of loss of containment; and (iii) bio-oils may present a marginal potential carcinogenicity. The approach outlined allows the collection of screening information on the potential hazards posed by the bio-oils. This can be particularly useful when limited time and analytical resources reduce the possibility to obtain detailed specific experimental data. Copyright © 2012 Elsevier B.V. All rights reserved.

Spray-Pyrolyzed Three-Dimensional CuInS2 Solar Cells on Nanocrystalline-Titania Electrodes with Chemical-Bath-Deposited Inx(OH)ySz Buffer Layers

NASA Astrophysics Data System (ADS)

Nguyen, Duy-Cuong; Mikami, Yuki; Tsujimoto, Kazuki; Ryo, Toshihiro; Ito, Seigo

2012-10-01

Three-dimensional (3D) compound solar cells with the structure of have been fabricated by spray pyrolysis deposition of CuInS2 and chemical-bath deposition of Inx(OH)ySz for the light absorber and buffer layer, respectively. The effect of deposition and annealing conditions of Inx(OH)ySz on the photovoltaic properties of 3D CuInS2 solar cells was investigated. Inx(OH)ySz annealed in air ambient showed a better cell performance than those annealed in nitrogen ambient and without annealing. The improvement of the performance of cells with Inx(OH)ySz buffer layers annealed in air ambient is due to the increase in oxide concentration in the buffer layers [confirmed by X-ray photoelectron spectroscopy (XPS) measurement]. Among cells with Inx(OH)ySz buffer layers deposited for 1, 1.5, 1.75, and 2 h, that with Inx(OH)ySz deposited for 1.75 h showed the best cell performance. The best cell performance was observed for Inx(OH)ySz deposited for 1.75 h with annealing at 300 °C for 30 min in air ambient, and cell parameters were 22 mA cm-2 short-circuit photocurrent density, 0.41 V open-circuit voltage, 0.35 fill factor, and 3.2% conversion efficiency.

Spray Characterization of Gas-to-Liquid Synthetic Jet Fuels

NASA Astrophysics Data System (ADS)

Kannaiyan, Kumaran; Sadr, Reza; GTL jet fuel Consortium Team

2012-11-01

Gas-to-Liquid (GTL) Synthetic Paraffinic Kerosene (SPK) fuel obtained from Fischer-Tropsch synthesis has grabbed the global attention due to its cleaner combustion characteristics. GTL fuels are expected to meet the vital qualities such as atomization, combustion and emission characteristics of conventional jet fuels. It is imperative to understand fuel atomization in order to gain insights on the combustion and emission aspects of an alternative fuel. In this work spray characteristics of GTL-SPK, which could be used as a drop-in fuel in aircraft gas turbine engines, is studied. This work outlines the spray experimental facility, the methodology used and the results obtained using two SPK's with different chemical compositions. The spray characteristics, such as droplet size and distribution, are presented at three differential pressures across a simplex nozzle and compared with that of the conventional Jet A-1 fuel. Experimental results clearly show that although the chemical composition is significantly different between SPK's, the spray characteristics are not very different. This could be attributed to the minimal difference in fluid properties between the SPK's. Also, the spray characteristics of SPK's show close resemblance to the spray characteristics of Jet A-1 fuel.

Pyrolysis system evaluation study

NASA Technical Reports Server (NTRS)

1974-01-01

An evaluation of two different pyrolysis concepts which recover energy from solid waste was conducted in order to determine the merits of each concept for integration into a Integrated Utility System (IUS). The two concepts evaluated were a Lead Bath Furnace Pyrolysis System and a Slagging Vertical Shaft, Partial Air Oxidation Pyrolysis System. Both concepts will produce a fuel gas from the IUS waste and sewage sludge which can be used to offset primary fuel consumption in addition to the sanitary disposal of the waste. The study evaluated the thermal integration of each concept as well as the economic impact on the IUS resulting from integrating each pyrolysis concepts. For reference, the pyrolysis concepts were also compared to incineration which was considered the baseline IUS solid waste disposal system.

Maximizing the stability of pyrolysis oil/diesel fuel emulsions

USDA-ARS?s Scientific Manuscript database

Several emulsions consisting of biomass pyrolysis oil (bio-oil) in diesel fuel were produced and analyzed for stability over time. An ultrasonic probe was used to generate microscopic droplets of bio-oil suspended in diesel fuel, and this emulsion was stabilized using surfactant chemicals. The most...

Value added liquid products from waste biomass pyrolysis using pretreatments.

PubMed

Das, Oisik; Sarmah, Ajit K

2015-12-15

Douglas fir wood, a forestry waste, was attempted to be converted into value added products by pretreatments followed by pyrolysis. Four different types of pretreatments were employed, namely, hot water treatment, torrefaction, sulphuric acid and ammonium phosphate doping. Subsequently, pyrolysis was done at 500°C and the resulting bio-oils were analysed for their chemical composition using Karl Fischer titration, thermogravimetry, ion exchange, and gas chromatography. Pretreatment with acid resulted in the highest yield of bio-oil (~60%). The acid and salt pretreatments were responsible for drastic reduction in the lignin oligomers and enhancement of water content in the pyrolytic liquid. The quantity of xylose/mannose reduced as a result of pretreatments. Although, the content of fermentable sugars remained similar across all the pretreatments, the yield of levoglucosan increased. Pretreatment of the biomass with acid yielded the highest amount of levoglucosan in the bio-oil (13.21%). The acid and salt pretreatments also elevated the amount of acetic acid in the bio-oils. Addition of acid and salt to the biomass altered the interaction of cellulose-lignin in the pyrolysis regime. Application of pretreatments should be based on the intended end use of the liquid product having a desired chemical composition. Copyright © 2015 Elsevier B.V. All rights reserved.

Lead (Pb2+) and copper (Cu2+) remediation from water using superparamagnetic maghemite (γ-Fe2O3) nanoparticles synthesized by Flame Spray Pyrolysis (FSP).

PubMed

Rajput, Shalini; Singh, Lok P; Pittman, Charles U; Mohan, Dinesh

2017-04-15

Superparamagnetic maghemite (γ-Fe 2 O 3 ) nanoparticles of controllable morphology were successfully synthesized using a flame spray pyrolysis (FSP) technique. Their physico-chemical properties, size, morphology, and surface chemistries were determined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), selected area electron diffraction patterns (SAED), SEM-EDX, scanning electron microscopy (SEM), and pH ZPC (6.3). Elemental contents before and after adsorption were identified using energy dispersive X-ray fluorescence (ED-XRF), energy dispersive X-ray analysis (EDX) and elemental mapping. Surface area (S BET 79.35m 2 /g) and size distribution analyses were conducted using a surface area analyzer and dynamic light scattering (DLS), respectively. The magnetic moment (44.5 at 300K and 50.16 at 2K) was determined using a physical properties measurement system (PPMS). The first adsorption study using γ-Fe 2 O 3 nanoparticles synthesized by FSP to successfully remediate Pb 2+ and Cu 2+ from water is reported. Batch adsorption studies were carried out. An optimum pH of 5.0 was studied for Pb 2+ and Cu 2+ removal. Pb 2+ and Cu 2+ removal mechanisms by these maghemite nanoparticles were presented. The adsorption of Pb 2+ and Cu 2+ was highly pH-dependent. The metal ion uptake was mainly governed by electrostatic attractions. Sorption kinetic data followed the pseudo-second-order model. The Freundlich, Langmuir, Redlich-Peterson, Radke and Sips adsorption isotherm models were applied to interpret equilibrium data. The Freundlich and Langmuir isotherm equations best fit the respective equilibrium data for Pb 2+ and Cu 2+ . The maximum Langmuir adsorption capacities of these maghemite nanoparticles were 68.9mg/g at 45°C for Pb 2+ and 34.0mg/g at 25 °C for Cu 2+ . Thus, these maghemite nanoparticles made by FSP were readily prepared, characterized and showed promise for remediating heavy metal ions from

Pyrolysis and dehalogenation of plastics from waste electrical and electronic equipment (WEEE): a review.

PubMed

Yang, Xiaoning; Sun, Lushi; Xiang, Jun; Hu, Song; Su, Sheng

2013-02-01

Plastics from waste electrical and electronic equipment (WEEE) have been an important environmental problem because these plastics commonly contain toxic halogenated flame retardants which may cause serious environmental pollution, especially the formation of carcinogenic substances polybrominated dibenzo dioxins/furans (PBDD/Fs), during treat process of these plastics. Pyrolysis has been proposed as a viable processing route for recycling the organic compounds in WEEE plastics into fuels and chemical feedstock. However, dehalogenation procedures are also necessary during treat process, because the oils collected in single pyrolysis process may contain numerous halogenated organic compounds, which would detrimentally impact the reuse of these pyrolysis oils. Currently, dehalogenation has become a significant topic in recycling of WEEE plastics by pyrolysis. In order to fulfill the better resource utilization of the WEEE plastics, the compositions, characteristics and dehalogenation methods during the pyrolysis recycling process of WEEE plastics were reviewed in this paper. Dehalogenation and the decomposition or pyrolysis of WEEE plastics can be carried out simultaneously or successively. It could be 'dehalogenating prior to pyrolysing plastics', 'performing dehalogenation and pyrolysis at the same time' or 'pyrolysing plastics first then upgrading pyrolysis oils'. The first strategy essentially is the two-stage pyrolysis with the release of halogen hydrides at low pyrolysis temperature region which is separate from the decomposition of polymer matrixes, thus obtaining halogenated free oil products. The second strategy is the most common method. Zeolite or other type of catalyst can be used in the pyrolysis process for removing organohalogens. The third strategy separate pyrolysis and dehalogenation of WEEE plastics, which can, to some degree, avoid the problem of oil value decline due to the use of catalyst, but obviously, this strategy may increase the cost of

Physical and Chemical Properties of Bio-Oils From Microwave Pyrolysis of Corn Stover

NASA Astrophysics Data System (ADS)

Yu, Fei; Deng, Shaobo; Chen, Paul; Liu, Yuhuan; Wan, Yiqin; Olson, Andrew; Kittelson, David; Ruan, Roger

This study was aimed to understand the physical and chemical properties of pyrolytic bio-oils produced from microwave pyrolysis of corn stover regarding their potential use as gas turbine and home heating fuels. The ash content, solids content, pH, heating value, minerals, elemental ratio, moisture content, and viscosity of the bio-oils were determined. The water content was approx 15.2 wt%, solids content 0.22 wt%, alkali metal content 12 parts per million, dynamic viscosity 185 mPa·s at 40°C, and gross high heating value 17.5 MJ/kg for a typical bio-oil produced. Our aging tests showed that the viscosity and water content increased and phase separation occurred during the storage at different temperatures. Adding methanol and/or ethanol to the bio-oils reduced the viscosity and slowed down the increase in viscosity and water content during the storage. Blending of methanol or ethanol with the bio-oils may be a simple and cost-effective approach to making the pyrolytic bio-oils into a stable gas turbine or home heating fuels.

Physical and chemical properties of bio-oils from microwave pyrolysis of corn stover.

PubMed

Yu, Fei; Deng, Shaobo; Chen, Paul; Liu, Yuhuan; Wan, Yiqin; Olson, Andrew; Kittelson, David; Ruan, Roger

2007-04-01

This study was aimed to understand the physical and chemical properties of pyrolytic bio-oils produced from microwave pyrolysis of corn stover regarding their potential use as gas turbine and home heating fuels. The ash content, solids content, pH, heating value, minerals, elemental ratio, moisture content, and viscosity of the bio-oils were determined. The water content was approx 15.2 wt%, solids content 0.22 wt%, alkali metal content 12 parts per million, dynamic viscosity 185 mPa.s at 40 degrees C, and gross high heating value 17.5 MJ/kg for a typical bio-oil produced. Our aging tests showed that the viscosity and water content increased and phase separation occurred during the storage at different temperatures. Adding methanol and/or ethanol to the bio-oils reduced the viscosity and slowed down the increase in viscosity and water content during the storage. Blending of methanol or ethanol with the bio-oils may be a simple and cost-effective approach to making the pyrolytic bio-oils into a stable gas turbine or home heating fuels.

Characterization of Source Signatures of Fine Roadway Particles by Pyrolysis-GC-MS

NASA Astrophysics Data System (ADS)

van Bergen, S. K.; Holmén, B. A.

2001-12-01

Fine particulate matter, defined as particles with an aerodynamic diameter less than 2.5 μ m (PM2.5), is of growing concern due to its detrimental effects on human health and the environment. Roadway traffic generates a significant fraction of PM2.5 in urban areas. Since exposure to fine particles derived from mobile sources commonly occurs, understanding the physicochemical processes that contribute to the generation, transport and atmospheric reactivity of roadway PM is important. Factors that influence the properties of roadway PM include: the mass, number and size distribution of the particles as well as their chemical composition. These factors are partially determined by the sources of the roadway particles. The focus of this effort is to identify unique organic chemical profiles of known roadway sources of PM using a new rapid characterization technique. A pyrolysis GC-MS analytical method is being developed to uniquely characterize the sources of roadway PM2.5 such as brake dust, tire wear, and direct emissions from diesel and gasoline engines. The source profiles will be used in conjunction with measurements of the composition of ambient roadway PM to determine the importance of the various roadway sources. The advantages of this technique over conventional solvent extractions include: smaller (mg) sample mass requirements, short extraction times and minimal sample handing. Preliminary two-step pyrolysis results will be presented for PM samples from individual sources and an ambient roadway. Specific analytical issues that will be discussed include: modifications of commercial pyrolysis hardware to improve reproducibility; desorption versus pyrolysis; developing appropriate pyrolysis programs for heterogenous sample materials; and method detection limits.

Pyrolysis-combustion 14C dating of soil organic matter

USGS Publications Warehouse

Wang, Hongfang; Hackley, Keith C.; Panno, S.V.; Coleman, D.D.; Liu, J.C.-L.; Brown, J.

2003-01-01

Radiocarbon (14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (??13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and ??13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and ??13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Relationships between Chemical Characteristics and Phytotoxicity of Biochar from Poultry Litter Pyrolysis.

PubMed

Rombolà, Alessandro G; Marisi, Giovanni; Torri, Cristian; Fabbri, Daniele; Buscaroli, Alessandro; Ghidotti, Michele; Hornung, Andreas

2015-08-05

Three biochars were prepared by intermediate pyrolysis from poultry litter at different temperatures (400, 500, and 600 °C with decreasing residence times) and compared with biochars from corn stalk prepared under the same pyrolysis conditions. The phytotoxicity of these biochars was estimated by means of seed germination tests on cress (Lepidium sativum L.) conducted in water suspensions (at 2, 5, and 40 g/L) and on biochars wetted according to their water-holding capacity. Whereas the seeds germinated after 72 h in water suspensions with corn stalk biochar were similar to the control (water only), significant inhibition was observed with poultry litter biochars. In comparison to corn stalk, poultry litter generated biochars with higher contents of ash, ammonium, nitrogen, and volatile fatty acids (VFAs) and a similar concentration of polycyclic aromatic hydrocarbons (PAHs). Results from analytical pyrolysis (Py-GC-MS) indicated that nitrogen-containing organic compounds (NCCs) and aliphatic components were distinctive constituents of the thermally labile fraction of poultry litter biochar. The inhibition of germination due to poultry litter biochar produced at 400 °C (PL400) was suppressed after solvent extraction or treatment with active sludge. A novel method based on solid-phase microextraction (SPME) enabled the identification of mobile organic compounds in PL400 capable of being released in air and water, including VFAs and NCCs. The higher phytotoxicity of poultry litter than corn biochars was tentatively attributed to hydrophilic biodegradable substances derived from lipids or proteins removable by water leaching or microbial treatments.

High-capacity cathodes for lithium-ion batteries from nanostructured LiFePO4 synthesized by highly-flexible and scalable flame spray pyrolysis

NASA Astrophysics Data System (ADS)

Hamid, N. A.; Wennig, S.; Hardt, S.; Heinzel, A.; Schulz, C.; Wiggers, H.

2012-10-01

Olivine, LiFePO4 is a promising cathode material for lithium-ion batteries due to its low cost, environmental acceptability and high stability. Its low electric conductivity prevented it for a long time from being used in large-scale applications. Decreasing its particle size along with carbon coating significantly improves electronic conductivity and lithium diffusion. With respect to the controlled formation of very small particles with large specific surface, gas-phase synthesis opens an economic and flexible route towards high-quality battery materials. Amorphous FePO4 was synthesized as precursor material for LiFePO4 by flame spray pyrolysis of a solution of iron acetylacetonate and tributyl phosphate in toluene. The pristine FePO4 with a specific surface from 126-218 m2 g-1 was post-processed to LiFePO4/C composite material via a solid-state reaction using Li2CO3 and glucose. The final olivine LiFePO4/C particles still showed a large specific surface of 24 m2 g-1 and were characterized using X-ray diffraction (XRD), electron microscopy, X-ray photoelectron spectrocopy (XPS) and elemental analysis. Electrochemical investigations of the final LiFePO4/C composites show reversible capacities of more than 145 mAh g-1 (about 115 mAh g-1 with respect to the total coating mass). The material supports high drain rates at 16 C while delivering 40 mAh g-1 and causes excellent cycle stability.

Natural rubber, a potential alternative source for the synthesis of renewable fuels via Hydrous Pyrolysis

NASA Astrophysics Data System (ADS)

Ahmad, N.; Dayana, S. A. S.; Abnisa, F.; Mohd, W. A. W. D.

2018-03-01

Natural rubber is a humid agricultural harvest, which mostly contains hydrocarbon cis-1, 4-Poly isoprene. Through depolymerisation technology, the natural rubber can be changed into liquid product, and then it can be subsequently utilized as a fuel or chemical feedstock. This article aims to provide an outlook on the natural rubber and its sources, which are available globally. Numerous depolymerisation processes, which include pyrolysis, gasification, chemical degradation, catalytic cracking and hydrogenation, were introduced in this paper, while the focus of discussion was emphasized on the hydrous pyrolysis process. Many studies have shown that the use of hydrous pyrolysis able to improve the depolymerisation process, e.g. the raw material can be feed without drying, the process can be carried out at lower temperature, only the water is used as the reaction medium, and it is easy to separate the water from oil product. The effect of operating parameters such as temperature, water to rubber mass ratio, reaction time and type of gases on the product yield and composition were reviewed in this paper. In addition, this paper also highlighted the eco-friendly and economic viability of the hydrous pyrolysis process.

A steady state model of agricultural waste pyrolysis: A mini review.

PubMed

Trninić, M; Jovović, A; Stojiljković, D

2016-09-01

Agricultural waste is one of the main renewable energy resources available, especially in an agricultural country such as Serbia. Pyrolysis has already been considered as an attractive alternative for disposal of agricultural waste, since the technique can convert this special biomass resource into granular charcoal, non-condensable gases and pyrolysis oils, which could furnish profitable energy and chemical products owing to their high calorific value. In this regard, the development of thermochemical processes requires a good understanding of pyrolysis mechanisms. Experimental and some literature data on the pyrolysis characteristics of corn cob and several other agricultural residues under inert atmosphere were structured and analysed in order to obtain conversion behaviour patterns of agricultural residues during pyrolysis within the temperature range from 300 °C to 1000 °C. Based on experimental and literature data analysis, empirical relationships were derived, including relations between the temperature of the process and yields of charcoal, tar and gas (CO2, CO, H2 and CH4). An analytical semi-empirical model was then used as a tool to analyse the general trends of biomass pyrolysis. Although this semi-empirical model needs further refinement before application to all types of biomass, its prediction capability was in good agreement with results obtained by the literature review. The compact representation could be used in other applications, to conveniently extrapolate and interpolate these results to other temperatures and biomass types. © The Author(s) 2016.

Evaluation of chemical spraying and environmental management efficacy in areas with minor previous application of integrated control actions for visceral leishmaniasis in Brazil.

PubMed

Lara-Silva, Fabiana de Oliveira; Michalsky, Érika Monteiro; Fortes-Dias, Consuelo Latorre; Fiuza, Vanessa de Oliveira Pires; Dias, Edelberto Santos

2017-12-01

Leishmaniases are vector-borne diseases that are transmitted to humans through the bite of Leishmania-infected phlebotomine sand flies (Diptera:Psychodidae). The main proved vector of visceral leishmaniais (VL) in the New World - Lutzomyia longipalpis - is well-adapted to urban areas and has extensive distribution within the five geographical regions of Brazil. Integrated public health actions directed for the vector, domestic reservoir and humans for the control of VL are preferentially applied in municipalities with higher epidemiological risk of transmission. In this study, we evaluated the individual impact of two main vector control actions - chemical spraying and environmental management - in two districts with no reported cases of human VL. Although belonging to an endemic municipality for VL in Brazil, the integrated control actions have not been applied in these districts due to the absence of human cases. The number of L. longipalpis captured in a two-year period was used as indicator of the population density of the vector. After chemical spraying a tendency of reduction in L. longipalpis was observed but with no statistical significance compared to the control. Environmental management was effective in that reduction and it may help in the control of VL by reducing the population density of the vector in a preventive and more permanent action, perhaps associated with chemical spraying. Copyright © 2017 Elsevier B.V. All rights reserved.

Pyrolysis characteristics of typical biomass thermoplastic composites

NASA Astrophysics Data System (ADS)

Cai, Hongzhen; Ba, Ziyu; Yang, Keyan; Zhang, Qingfa; Zhao, Kunpeng; Gu, Shiyan

The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA) has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite.

The impacts of biomass properties on pyrolysis yields, economic and environmental performance of the pyrolysis-bioenergy-biochar platform to carbon negative energy.

PubMed

Li, Wenqin; Dang, Qi; Brown, Robert C; Laird, David; Wright, Mark M

2017-10-01

This study evaluated the impact of biomass properties on the pyrolysis product yields, economic and environmental performance for the pyrolysis-biochar-bioenergy platform. We developed and applied a fast pyrolysis, feedstock-sensitive, regression-based chemical process model to 346 different feedstocks, which were grouped into five types: woody, stalk/cob/ear, grass/plant, organic residue/product and husk/shell/pit. The results show that biomass ash content of 0.3-7.7wt% increases biochar yield from 0.13 to 0.16kg/kg of biomass, and decreases biofuel yields from 87.3 to 40.7 gallons per tonne. Higher O/C ratio (0.88-1.12) in biomass decreases biochar yield and increases biofuel yields within the same ash content level. Higher ash content of biomass increases minimum fuel selling price (MFSP), while higher O/C ratio of biomass decreases MFSP within the same ash content level. The impact of ash and O/C ratio of biomass on GHG emissions are not consistent for all feedstocks. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Characterization of pyrolysis of waste printed circuit boards by high-resolution pyrolysis gas chromatography-mass spectrometry].

PubMed

Zhang, Yanhong; Huang, Hong; Xia, Zhengbin; Chen, Huanqin

2008-07-01

Thermal degradation of pyrolysis of waste circuit boards was investigated by high-resolution pyrolysis gas chromatography-mass spectrometry (PyGC-MS) and thermogravimetry (TG). In helium atmosphere, the products of FR-4 waste printed circuit board were pyrolyzed at 350, 450, 550, 650, and 750 degrees degrees C, separately, and the pyrolysis products were identified by online MS. The results indicated that the pyrolysis products of the FR-4 waste circuit board were three kinds of substances, such as the low boiling point products, phenol, bisphenol and their related products. Moreover, under 300 degrees degrees C, only observed less pyrolysis products. As the increase of pyrolysis temperature, the relative content of the low boiling point products increased. In the range of 450-650 degrees degrees C, the qualitative analysis and character were similar, and the relative contents of phenol and bisphenol were higher. The influence of pyrolysis temperature on pyrolyzate yields was studied. On the basis of the pyrolyzate profile and the dependence of pyrolyzate yields on pyrolysis temperature, the thermal degradation mechanism of brominated epoxy resin was proposed.

Metal-organic chemical vapor deposition of aluminum oxide thin films via pyrolysis of dimethylaluminum isopropoxide

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

Schmidt, Benjamin W.; Sweet, William J. III; Rogers, Bridget R.

2010-03-15

Metal-organic chemical vapor deposited aluminum oxide films were produced via pyrolysis of dimethylaluminum isopropoxide in a high vacuum reaction chamber in the 417-659 deg. C temperature range. Deposited films contained aluminum, oxygen, and carbon, and the carbon-to-aluminum ratio increased with increased deposition temperature. Aluminum-carbon bonding was observed in films deposited at 659 deg. C by x-ray photoelectron spectroscopy, but not in films deposited at 417 deg. C. The apparent activation energy in the surface reaction controlled regime was 91 kJ/mol. The O/Al and C/Al ratios in the deposited films were greater and less than, respectively, the ratios predicted by themore » stoichiometry of the precursor. Flux analysis of the deposition process suggested that the observed film stoichiometries could be explained by the participation of oxygen-containing background gases present in the reactor at its base pressure.« less

Improvement of Transparent Conducting Performance on Oxygen-Activated Fluorine-Doped Tin Oxide Electrodes Formed by Horizontal Ultrasonic Spray Pyrolysis Deposition.

PubMed

Koo, Bon-Ryul; Oh, Dong-Hyeun; Riu, Doh-Hyung; Ahn, Hyo-Jin

2017-12-27

In this study, highly transparent conducting fluorine-doped tin oxide (FTO) electrodes were fabricated using the horizontal ultrasonic spray pyrolysis deposition. In order to improve their transparent conducting performances, we carried out oxygen activation by adjusting the ratio of O 2 /(O 2 +N 2 ) in the carrier gas (0%, 20%, and 50%) used during the deposition process. The oxygen activation on the FTO electrodes accelerated the substitution concentration of F (F O • ) into the oxygen sites in the FTO electrode while the oxygen vacancy (V O • • ) concentration was reduced. In addition, due to growth of pyramid-shaped crystallites with (200) preferred orientations, this oxygen activation caused the formation of a uniform surface structure. As a result, compared to others, the FTO electrode prepared at 50% O 2 showed excellent electrical and optical properties (sheet resistance of ∼4.0 ± 0.14 Ω/□, optical transmittance of ∼85.3%, and figure of merit of ∼5.09 ± 0.19 × 10 -2 Ω -1 ). This led to a superb photoconversion efficiency (∼7.03 ± 0.20%) as a result of the improved short-circuit current density. The photovoltaic performance improvement can be defined by the decreased sheet resistance of FTO used as a transparent conducting electrode in dye-sensitized solar cells (DSSCs), which is due to the combined effect of the high carrier concentration by the improved F O • concentration on the FTO electrodes and the fasted Hall mobility by the formation of a uniform FTO surface structure and distortion relaxation on the FTO lattices resulting from the reduced V O • • • concentration.

Liquid hydrocarbon fuels obtained by the pyrolysis of soybean oils.

PubMed

Junming, Xu; Jianchun, Jiang; Yanju, Lu; Jie, Chen

2009-10-01

The pyrolysis reactions of soybean oils have been studied. The pyrolytic products were analyzed by GC-MS and FTIR and show the formation of olefins, paraffins, carboxylic acids and aldehydes. Several kinds of catalysts were compared. It was found that the amounts of carboxylic acids and aldehydes were significantly decreased by using base catalysts such as Na(2)CO(3) and K(2)CO(3). The low acid value pyrolytic products showed good cold flow properties and good solubility in diesel oil at low temperature. The results presented in this work have shown that the pyrolysis of soybean oils generates fuels that have chemical composition similar to petroleum based fuels.

Chemical Stability and Biological Properties of Plasma-Sprayed CaO-SiO2-ZrO2 Coatings

NASA Astrophysics Data System (ADS)

Liang, Ying; Xie, Youtao; Ji, Heng; Huang, Liping; Zheng, Xuebin

2010-12-01

In this work, calcia-stabilized zirconia powders were coated by silica derived from tetraethoxysilane (TEOS) hydrolysis. After calcining at 1400 °C, decalcification of calcia-stabilized zirconia by silica occurred and powders composed of Ca2SiO4, ZrO2, and CaZrO3 were prepared. We produced three kinds of powders with different Ca2SiO4 contents [20 wt.% (denoted as CZS2), 40 wt.% (denoted as CZS4), and 60 wt.% (denoted as CZS6)]. The obtained powders were sprayed onto Ti-6Al-4V substrates using atmospheric plasma spraying. The microstructure of the powders and coatings were analyzed. The dissolution rates of the coatings were assessed by monitoring the ions release and mass losses after immersion in Tris-HCl buffer solution. Results showed that the chemical stability of the coatings were significantly improved compared with pure calcium silicate coatings, and increased with the increase of Zr contents. The CZS4 coating showed not only good apatite-formation ability in simulated body fluid, but also well attachment and proliferation capability for the canine bone marrow stem cells. Results presented here indicate that plasma-sprayed CZS4 coating has medium dissolution rate and good biological properties, suggesting its potential use as bone implants.

Synthesis of carbon nanomaterials from different pyrolysis techniques: a review

NASA Astrophysics Data System (ADS)

Umer Zahid, Muhammad; Pervaiz, Erum; Hussain, Arshad; Shahzad, Muhammad Imran; Niazi, Muhammad Bilal Khan

2018-05-01

In the current age, the significance of carbon-based nanomaterials for many applications has made the efforts for the facile synthesis methods from abundantly available wastes in a cost-effective way. Pyrolysis in a broad spectrum is commonly employed for the synthesis of carbon nanostructures by thermally treating the organic waste. The mechanism of growth of the nanoparticles determines the functional distribution of nanoparticles based on the growing size, medium, and physio-chemical properties. Carbon nanomaterial’s growth is a complicated process which is profoundly influenced by temperature, catalyst, and type of precursor. Nowadays, significant progress has been made in improving nanomaterial’s growth techniques, opening new paths for commercial production of carbon-based nanomaterials. The most promising are the methods involving hydrocarbon-rich organic waste as the feed source. In this review, synthesis of carbon-based nanomaterials, specifically carbon nanotubes (CNTs), Carbon nanofibers (CNFs) and Graphene (G) are discussed by different pyrolysis techniques. Furthermore, the review explores recent advancements made in the context of pyrolysis.

Liquid-feed flame spray pyrolysis synthesis of oxide nanopowders for the processing of ceramic composites

NASA Astrophysics Data System (ADS)

Taylor, Nathan John

In the liquid-feed flame spray pyrolysis (LF-FSP) process, alcohol solutions of metalloorganic precursors are aerosolized by O2 and combusted. The metal oxide combustion products are rapidly quenched (< 10 ms) from flame temperatures of 1500°C to temperatures < 400° C, limiting particle growth. The resulting nanopowders are typically agglomerated but unaggregated. Here, we demonstrate two processing approaches to dense materials: nanopowders with the exact composition, and mixed single metal oxide nanopowders. The effect of the initial degree of phase separation on the final microstructures was determined by sintering studies. Our first studies included the production of yttrium aluminum garnet, Y3Al5O12 (YAG), tubes which we extruded from a thermoplastic/ceramic blend. At equivalent final densities, we found finer grain sizes in the from the mixed Y2O3 and Al2 O3 nanopowders, which was attributed to densification occurring before full transformation to the YAG phase. The enhanced densification in production of pure YAG from the reactive sintering process led us to produce composites in the YAG/alpha-Al 2O3 system. Finally, a third Y2O3 stabilized ZrO2 (YSZ) phase was added to further refine grain sizes using the same two processing approaches. In a separate study, single-phase metastable Al2O3 rich spinels with the composition MO•3Al 2O3 where M = Mg, Ni, and Co were sintered to produce dense MAl2O4/alpha-Al2O3 composites. All of these studies provide a test of the bottom-up approach; that is, how the initial length scale of mixing affects the final composite microstructure. Overall, the length scale of mixing is highly dependent upon the specific oxide composites studied. This work provides a processing framework to be adopted by other researchers to further refine microstructural size. LF-FSP flame temperatures were mapped using different alcohols with different heats of combustion: methanol, ethanol, 1-propanol, and n-butanol. The effect of different

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

Preparation and characterization of sprayed FTO thin films

NASA Astrophysics Data System (ADS)

Abd-Lefdil, M.; Diaz, R.; Bihri, H.; Aouaj, M. Ait; Rueda, F.

2007-06-01

Fluorine doped tin oxide (FTO) thin films have been prepared by spray pyrolysis technique with no further annealing. Films with 2.5% of fluorine grown at 400 °C present a single phase and exhibit a tetragonal structure with lattice parameters a = 4.687 Å and c = 3.160 Å. Scanning electron micrographs showed homogeneous surfaces with average grain size around 190 nm. The films are transparent in the visible zone and exhibit a high reflectance in the near infrared region. The best electrical resistivity was 6.3 × 10-4 Ω cm for FTO with 2.5% of fluorine. The ratio of transmittance in the visible to the sheet resistance are in the 0.57 × 10-2 1.96 × 10-2 {Ω }-1 range.

Inherent health and environmental risk assessment of nanostructured metal oxide production processes.

PubMed

Torabifard, Mina; Arjmandi, Reza; Rashidi, Alimorad; Nouri, Jafar; Mohammadfam, Iraj

2018-01-10

The health and environmental effects of chemical processes can be assessed during the initial stage of their production. In this paper, the Chemical Screening Tool for Exposure and Environmental Release (ChemSTEER) software was used to compare the health and environmental risks of spray pyrolysis and wet chemical techniques for the fabrication of nanostructured metal oxide on a semi-industrial scale with a capacity of 300 kg/day in Iran. The pollution sources identified in each production process were pairwise compared in Expert Choice software using indicators including respiratory damage, skin damage, and environmental damages including air, water, and soil pollution. The synthesis of nanostructured zinc oxide using the wet chemical technique (with 0.523 wt%) leads to lower health and environmental risks compared to when spray pyrolysis is used (with 0.477 wt%). The health and environmental risk assessment of nanomaterial production processes can help select safer processes, modify the operation conditions, and select or modify raw materials that can help eliminate the risks.

REACTIONS OF FUEL NITROGEN COMPOUNDS UNDER CONDITIONS OF INERT PYROLYSIS

EPA Science Inventory

The paper describes the pyrolysis of fossil fuels and model nitrogen compounds in helium in a small quartz plow reactor, as part of a study of the chemical mechanisms involved in the conversion of fuel-nitrogen compounds to nitric oxide (NO) during combustion. Hydrogen cyanide (H...

Analysis and comparison of biomass pyrolysis/gasification condensates: Final report

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

Elliott, D.C.

1986-06-01

This report provides results of chemical and physical analysis of condensates from eleven biomass gasification and pyrolysis systems. The samples were representative of the various reactor configurations being researched within the Department of Energy, Biomass Thermochemical Conversion program. The condensates included tar phases and aqueous phases. The analyses included gross compositional analysis (elemental analysis, ash, moisture), physical characterization (pour point, viscosity, density, heat of combustion, distillation), specific chemical analysis (gas chromatography/mass spectrometry, infrared spectrophotometry, proton and carbon-13 nuclear magnetic resonance spectrometry) and biological activity (Ames assay and mouse skin tumorigenicity tests). These results are the first step of a longermore » term program to determine the properties, handling requirements, and utility of the condensates recovered from biomass gasification and pyrolysis. The analytical data demonstrates the wide range of chemical composition of the organics recovered in the condensates and suggests a direct relationship between operating temperature and chemical composition of the condensates. A continuous pathway of thermal degradation of the tar components as a function of temperature is proposed. Variations in the chemical composition of the organic components in the tars are reflected in the physical properties of tars and phase stability in relation to water in the condensate. The biological activity appears to be limited to the tars produced at high temperatures. 56 refs., 25 figs., 21 tabs.« less

Understanding the Behavior of the Oligomeric Fractions During Pyrolysis Oils Upgrading

NASA Astrophysics Data System (ADS)

Stankovikj, Filip

Fast pyrolysis oils represent most viable renewable sources for production of fuels and chemicals, and they could supplement significant portion of the depleting fossil fuels in near future. Progress on their utilization is impeded by their thermal and storage instability, lack of understanding of their complex composition and behavior during upgrading, including the poorly described water soluble fraction (WS). This work offers two new methodologies for simplified, and sensible description of the pyrolysis oils in terms of functional groups and chemical macro-families, augments our understanding of the composition of the WS, and the behavior of the heavy non-volatile fraction during pyrolysis oils stabilization. The concept of analyzing the volatile and non-volatile fraction in terms of functional groups has been introduced, and the quantification power of spectroscopic techniques (FTIR, 1H-NMR, UV fluorescence) for phenols, carbonyl and carboxyl groups was shown. The FT-ICR-MS van Krevelen diagram revealed the importance of dehydration reactions in pyrolysis oils and the presence of "pyrolytic humins" was hypothesized. For the first time the WS was analyzed with plethora of analytical techniques. This lead to proposition of a new characterization scheme based on functional groups, describing 90-100 wt.% of the bio-oils. The structure of idealized "pyrolytic humin" was further described as a random combination of 3-8 units of dehydrated sugars, coniferyl-type phenols, furans, and carboxylic acids attached on a 2,5-dioxo-6-hydroxyhexanal (DHH) backbone rich in carbonyl groups. TG-FTIR studies resulted in defining rules for fitting pyrolysis oils' DTG curves and assignment of TG residue. This second method is reliable for estimation of water content, light volatiles, WS and WIS. Finally, stabilization of two oils was analyzed through the prism of functional groups. Carbonyl and hydroxyl groups interconverted. The first attempt to follow silent 31P-NMR oxygen was

Microwave pyrolysis of distillers dried grain with solubles (DDGS) for biofuel production

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

Lei, Hanwu; Ren, Shoujie; Wang, Lu

2011-05-01

Microwave pyrolysis of distillers dried grain with solubles (DDGS) was investigated to determine the effects of pyrolytic conditions on the yields of bio-oil, syngas, and biochar. Pyrolysis process variables included reaction temperature, time, and power input. Microwave pyrolysis of DDGS was analyzed using response surface methodology to find out the effect of process variables on the biofuel (bio-oil and syn- gas) conversion yield and establish prediction models. Bio-oil recovery was in the range of 26.5–50.3 wt.% of the biomass. Biochar yields were 23.5–62.2% depending on the pyrolysis conditions. The energy con- tent of DDGS bio-oils was 28 MJ/kg obtained atmore » the 650 oC and 8 min, which was about 66.7% of the heat- ing value of gasoline. GC/MS analysis indicated that the biooil contained a series of important and useful chemical compounds: aliphatic and aromatic hydrocarbons. At least 13% of DDGS bio-oil was the same hydrocarbon compounds found in regular unleaded gasoline.« less

Microwave pyrolysis of distillers dried grain with solubles (DDGS) for biofuel production.

PubMed

Lei, Hanwu; Ren, Shoujie; Wang, Lu; Bu, Quan; Julson, James; Holladay, John; Ruan, Roger

2011-05-01

Microwave pyrolysis of distillers dried grain with solubles (DDGS) was investigated to determine the effects of pyrolytic conditions on the yields of bio-oil, syngas, and biochar. Pyrolysis process variables included reaction temperature, time, and power input. Microwave pyrolysis of DDGS was analyzed using response surface methodology to find out the effect of process variables on the biofuel (bio-oil and syngas) conversion yield and establish prediction models. Bio-oil recovery was in the range of 26.5-50.3 wt.% of the biomass. Biochar yields were 23.5-62.2% depending on the pyrolysis conditions. The energy content of DDGS bio-oils was 28 MJ/kg obtained at the 650°C and 8 min, which was about 66.7% of the heating value of gasoline. GC/MS analysis indicated that the biooil contained a series of important and useful chemical compounds: aliphatic and aromatic hydrocarbons. At least 13% of DDGS bio-oil was the same hydrocarbon compounds found in regular unleaded gasoline. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis Characterization and Decomposition Studies of tris[N-N-dibenzyidithocarbaso)Indium (III) Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

NASA Technical Reports Server (NTRS)

Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.

2005-01-01

This paper presents the results of the synthesis characterization and decomposition studies of tris[N-N-dibenzyidithocarbaso)Indium (III) with chemical spray deposition of polycrystalline CuInS2 on Copper Films.

Bio-oil production from fast pyrolysis of waste furniture sawdust in a fluidized bed.

PubMed

Heo, Hyeon Su; Park, Hyun Ju; Park, Young-Kwon; Ryu, Changkook; Suh, Dong Jin; Suh, Young-Woong; Yim, Jin-Heong; Kim, Seung-Soo

2010-01-01

The amount of waste furniture generated in Korea was over 2.4 million tons in the past 3 years, which can be used for renewable energy or fuel feedstock production. Fast pyrolysis is available for thermo-chemical conversion of the waste wood mostly into bio-oil. In this work, fast pyrolysis of waste furniture sawdust was investigated under various reaction conditions (pyrolysis temperature, particle size, feed rate and flow rate of fluidizing medium) in a fluidized-bed reactor. The optimal pyrolysis temperature for increased yields of bio-oil was 450 degrees C. Excessively smaller or larger feed size negatively affected the production of bio-oil. Higher flow and feeding rates were more effective for the production of bio-oil, but did not greatly affect the bio-oil yields within the tested ranges. The use of product gas as the fluidizing medium had a potential for increased bio-oil yields.

Influence of spray time on the optical and electrical properties of CoNi2S4 thin films

NASA Astrophysics Data System (ADS)

El Radaf, I. M.; Fouad, S. S.; Ismail, A. M.; Sakr, G. B.

2018-04-01

In this paper, a facile spray pyrolysis technique was utilized to synthesize CoNi2S4 thin films. The influence of spray time on the structural, optical and electrical properties of the CoNi2S4 thin films was studied. The x-ray diffraction studies of the CoNi2S4 thin films illustrate that the films exhibit a polycrystalline nature with cubic structure. The values of the lattice strain ε, and the dislocation density δ, were decreased as the spray time increase while the grain size has reverse manner to lattice strain ε, and the dislocation density δ. The transmittance and reflectance spectra of the CoNi2S4 thin films were recorded in the wavelength range of (400–2500) nm to evaluate the optical parameters of the CoNi2S4 thin films. Optical absorption coefficient of CoNi2S4 thin films revealed a presence of a direct energy gap and the values of energy gap were decreased from 1.68 to 1.53 eV as the spray time increases from 15 min to 45 min. The nonlinear refractive index of the CoNi2S4 thin films was increased with increasing of the spray time. The CoNi2S4 thin films exhibit single activation energy and the activation energy was decreased as the spray time increased.

Effect of torrefaction on biomass structure and hydrocarbon production from fast pyrolysis

DOE PAGES

Neupane, Sneha; Adhikari, Sushil; Wang, Zhouhong; ...

2015-01-27

Torrefaction has been shown to improve the chemical composition of bio-oils produced from fast pyrolysis by lowering its oxygen content and enhancing the aromatic yield. A Py-GC/MS study was employed to investigate the effect of torrefaction temperatures (225, 250 and 275 °C) and residence times (15, 30 and 45 min) on product distribution from non-catalytic and H +ZSM-5 catalyzed pyrolysis of pinewood. During torrefaction, structural transformations in biomass constitutive polymers: hemicellulose, cellulose and lignin took place, which were evaluated using component analysis, solid state CP/MAS 13C NMR and XRD techniques. Torrefaction caused deacetylation and decomposition of hemicellulose, cleavage of arylmore » ether linkages and demethoxylation of lignin, degradation of cellulose and an overall increase in aromaticity of biomass, all of which affected the product yield from pyrolysis of torrefied biomass. For non-catalytic pyrolysis, selectivity of phenolic compounds increased with an increase in torrefaction severity while that of furan compounds decreased. In the case of catalytic pyrolysis, the sample torrefied at 225 °C-30 min and 250 °C-15 min resulted in a significant increase in aromatic hydrocarbon (HC) and also total carbon yield (approx. 1.6 times higher) as compared to catalytic pyrolysis of non-torrefied pine. Cleavage of aryl ether linkages and demethoxylation in lignin due to torrefaction caused increased yield of phenolic compounds, which in the presence of a catalyst were dehydrated to form aromatic HC.« less

Pyrolysis polygeneration of poplar wood: Effect of heating rate and pyrolysis temperature.

PubMed

Chen, Dengyu; Li, Yanjun; Cen, Kehui; Luo, Min; Li, Hongyan; Lu, Bin

2016-10-01

The pyrolysis of poplar wood were comprehensively investigated at different pyrolysis temperatures (400, 450, 500, 550, and 600°C) and at different heating rates (10, 30, and 50°C/min). The results showed that BET surface area of biochar, the HHV of non-condensable gas and bio-oil reached the maximum values of 411.06m(2)/g, 14.56MJ/m(3), and 14.39MJ/kg, under the condition of 600°C and 30°C/min, 600°C and 50°C/min, and 550°C and 50°C/min, respectively. It was conducive to obtain high mass and energy yield of bio-oil at 500°C and higher heating rate, while lower pyrolysis temperature and heating rate contributed towards obtaining both higher mass yield and energy yield of biochar. However, higher pyrolysis temperature and heating rate contributed to obtain both higher mass yield and energy yield of the non-condensable gas. In general, compared to the heating rate, the pyrolysis temperature had more effect on the product properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimating the Temperature Experienced by Biomass Particles during Fast Pyrolysis Using Microscopic Analysis of Biochars

DOE PAGES

Thompson, Logan C.; Ciesielski, Peter N.; Jarvis, Mark W.; ...

2017-07-12

Here, biomass particles can experience variable thermal conditions during fast pyrolysis due to differences in their size and morphology, and from local temperature variations within a reactor. These differences lead to increased heterogeneity of the chemical products obtained in the pyrolysis vapors and bio-oil. Here we present a simple, high-throughput method to investigate the thermal history experienced by large ensembles of particles during fast pyrolysis by imaging and quantitative image analysis. We present a correlation between the surface luminance (darkness) of the biochar particle and the highest temperature that it experienced during pyrolysis. Next, we apply this correlation to large,more » heterogeneous ensembles of char particles produced in a laminar entrained flow reactor (LEFR). The results are used to interpret the actual temperature distributions delivered by the reactor over a range of operating conditions.« less

Char yield on pyrolysis of cellulose

Treesearch

A. Broido; Maxine A. Nelson

1975-01-01

Whether the pyrolysis of cellulose is conducted in an inert medium or in air, partial pyrolysis at a lower temperature increases the char yield subsequently obtained after 1 hour at 370°C. The results are consistent with a pyrolysis scheme in which two competing sequences of cellulose pyrolysis reactions are initiated by (1) an intermolecular dehydration leading to...

Analytical pyrolysis mass spectrometry: new vistas opened by temperature-resolved in-source PYMS

NASA Astrophysics Data System (ADS)

Boon, Jaap J.

1992-09-01

Analytical pyrolysis mass spectrometry (PYMS) is introduced and its applications to the analysis of synthetic polymers, biopolymers, biomacromolecular systems and geomacromolecules are critically reviewed. Analytical pyrolysis inside the ionisation chamber of a mass spectrometer, i.e. in-source PYMS, gives a complete inventory of the pyrolysis products evolved from a solid sample. The temperature-resolved nature of the experiment gives a good insight into the temperature dependence of the volatilisation and pyrolytic dissociation processes. Chemical ionisation techniques appear to be especially suitable for the analysis of oligomeric fragments released in early stages of the pyrolysis of polymer systems. Large oligomeric fragments were observed for linear polymers such as cellulose (pentadecamer), polyhydroxyoctanoic acid (tridecamer) and polyhydroxybutyric acid (heneicosamer). New in-source PYMS data are presented on artists' paints, the plant polysaccharides cellulose and xyloglucan, several microbial polyhydroxyalkanoates, wood and enzyme-digested wood, biodegraded roots and a fossil cuticle of Miocene age. On-line and off-line pyrolysis chromatography mass spectrometric approaches are also discussed. New data presented on high temperature gas chromatography--mass spectrometry of deuterio-reduced permethylated pyrolysates of cellulose lead to a better understanding of polysaccharide dissociation mechanisms. Pyrolysis as an on-line sample pretreatment method for organic macromolecules in combination with MS techniques is a very challenging field of mass spectrometry. Pyrolytic dissociation and desorption is not at all a chaotic process but proceeds according to very specific mechanisms.

A review of catalytic microwave pyrolysis of lignocellulosic biomass for value-added fuel and chemicals.

PubMed

Morgan, Hervan Marion; Bu, Quan; Liang, Jianghui; Liu, Yujing; Mao, Hanping; Shi, Aiping; Lei, Hanwu; Ruan, Roger

2017-04-01

Lignocellulosic biomass is an abundant renewable resource and can be efficiently converted into bio-energy by a bio-refinery. From the various techniques available for biomass thermo-chemical conversion; microwave assisted pyrolysis (MAP) seems to be the very promising. The principles of microwave technology were reviewed and the parameters for the efficient production of bio-oil using microwave technology were summarized. Microwave technology by itself cannot efficiently produce high quality bio-oil products, catalysts are used to improve the reaction conditions and selectivity for valued products during MAP. The catalysts used to optimize MAP are revised in the development of this article. The origins for bio-oils that are phenol rich or hydrocarbon rich are reviewed and their experimental results were summarized. The kinetics of MAP is discussed briefly in the development of the article. Future prospects and scientific development of MAP are also considered in the development of this article. Copyright © 2017 Elsevier Ltd. All rights reserved.

The comparative kinetic analysis of Acetocell and Lignoboost® lignin pyrolysis: the estimation of the distributed reactivity models.

PubMed

Janković, Bojan

2011-10-01

The non-isothermal pyrolysis kinetics of Acetocell (the organosolv) and Lignoboost® (kraft) lignins, in an inert atmosphere, have been studied by thermogravimetric analysis. Using isoconversional analysis, it was concluded that the apparent activation energy for all lignins strongly depends on conversion, showing that the pyrolysis of lignins is not a single chemical process. It was identified that the pyrolysis process of Acetocell and Lignoboost® lignin takes place over three reaction steps, which was confirmed by appearance of the corresponding isokinetic relationships (IKR). It was found that major pyrolysis stage of both lignins is characterized by stilbene pyrolysis reactions, which were subsequently followed by decomposition reactions of products derived from the stilbene pyrolytic process. It was concluded that non-isothermal pyrolysis of Acetocell and Lignoboost® lignins can be best described by n-th (n>1) reaction order kinetics, using the Weibull mixture model (as distributed reactivity model) with alternating shape parameters. Copyright © 2011 Elsevier Ltd. All rights reserved.

Supercritical water pyrolysis of sewage sludge.

PubMed

Ma, Wenchao; Du, Guiyue; Li, Jian; Fang, Yuanhao; Hou, Li'an; Chen, Guanyi; Ma, Degang

2017-01-01

Municipal sewage sludge (SS) from wastewater treatment plant containing high water content (>85wt.%), lead to the difficulty of co-combustion with MSW or coal due to the high cost of drying. This study explores an alternative method by supercritical water (SCW) pyrolysis of sewage sludge (SS) in a high pressure reaction vessel. The effects of temperature and moisture content of SS on yield and composition of the products (bio-oil, bio char and non-condensable gas) were studied. A temperature of 385°C and moisture content of 85wt.% were found to be the optimum conditions for the maximum bio-oil production of 37.23wt.%, with a higher heating value of 31.08MJ/kg. In the optimum condition, the yields of aliphatic hydrocarbon and phenols were about 29.23wt.% and 12.51wt.%, respectively. The physical and chemical properties of bio-char were analyzed by using XRF and BET. Results of GC analyses of NCG showed that it has the maximum HHV of 13.39MJ/m 3 at 445°C and moisture content of 85wt.%. The reaction path from SS to bio-oil through SCW pyrolysis was given. Moreover, carbon balance was calculated for the optimal condition, and finding out that 64.27wt.% of the carbon content was transferred from SS to bio-oil. Finally, this work demonstrates that the SCW pyrolysis is a promising disposal method for SS. Copyright © 2016. Published by Elsevier Ltd.

Influence of pyrolysis temperature on lead immobilization by chemically modified coconut fiber-derived biochars in aqueous environments.

PubMed

Wu, Weidong; Li, Jianhong; Niazi, Nabeel Khan; Müller, Karin; Chu, Yingchao; Zhang, Lingling; Yuan, Guodong; Lu, Kouping; Song, Zhaoliang; Wang, Hailong

2016-11-01

Biochar has received widespread attention as an eco-friendly and efficient material for immobilization of toxic heavy metals in aqueous environments. In the present study, three types of coconut fiber-derived biochars were obtained by pyrolyzing at three temperatures, i.e., 300, 500, and 700 °C. In addition, nine types of biochars were prepared by chemical modification with ammonia, hydrogen peroxide, and nitric acid, respectively, which were used to investigate changes in physico-chemical properties by inter alia, Fourier transformation infrared spectrophotometry (FTIR), scanning electron microscope (SEM), and BET specific surface area analysis. Batch sorption experiments were carried out to determine the sorption capacity of the biochars for lead (Pb) in aqueous solutions. Results showed that the cation exchange capacity of biochar pyrolyzed at 300 °C and modified with nitric acid increased threefold compared to the control. Loosely corrugated carbon surface and uneven carbon surface of the biochar pyrolyzed at 300 °C were produced during ammonia and nitric acid modifications. Removal rate of Pb by the coconut biochar pyrolyzed at 300 °C and modified with ammonia was increased from 71.8 to 99.6 % compared to the untreated biochar in aqueous solutions containing 100 mg L -1 Pb. However, chemical modification did not enhance adsorption of Pb of the biochars pyrolyzed at higher temperatures (e.g., 500 or 700 °C), indicating that resistance of biochars to chemical treatment increased with pyrolysis temperature.

Aromatics and phenols from catalytic pyrolysis of Douglas fir pellets in microwave with ZSM-5 as a catalyst

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

Wang, Lu; Lei, Hanwu; Ren, Shoujie

Microwave assisted catalytic pyrolysis was investigated to convert Douglas fir pellets to bio-oils by a ZSM-5 Zeolite catalyst. A central composite experimental design (CCD) was used to optimize the catalytic pyrolysis process. The effects of reaction time, temperature and catalyst to biomass ratio on the bio-oil, syngas, and biochar yields were determined. GC/MS analysis results showed that the bio-oil contained a series of important and useful chemical compounds. Phenols, guaiacols, and aromatic hydrocarbons were the most abundant compounds which were about 50-82 % in bio-oil depending on the pyrolysis conditions. Comparison between the bio-oils from microwave pyrolysis with and withoutmore » catalyst showed that the catalyst increased the content of aromatic hydrocarbons and phenols. A reaction pathway was proposed for microwave assisted catalyst pyrolysis of Douglas fir pellets.« less

Intermediate pyrolysis of agro-industrial biomasses in bench-scale pyrolyser: Product yields and its characterization.

PubMed

Tinwala, Farha; Mohanty, Pravakar; Parmar, Snehal; Patel, Anant; Pant, Kamal K

2015-01-01

Pyrolysis of woody biomass, agro-residues and seed was carried out at 500 ± 10 °C in a fixed bed pyrolyser. Bio-oil yield was found varying from 20.5% to 47.5%, whereas the biochar and pyrolysis gas ranged from 27.5% to 40% and 24.5% to 40.5%, respectively. Pyrolysis gas was measured for flame temperature along with CO, CO2, H2, CH4 and other gases composition. HHV of biochar (29.4 MJ/kg) and pyrolitic gas (8.6 MJ/kg) of woody biomass was higher analogous to sub-bituminous coal and steam gasification based producer gas respectively, whereas HHV of bio-oil obtained from seed (25.6 MJ/kg) was significantly more than husks, shells and straws. TGA-DTG studies showed the husks as potential source for the pyrolysis. Bio-oils as a major by-product of intermediate pyrolysis have several applications like substitute of furnace oil, extraction of fine chemicals, whereas biochar as a soil amendment for enhancing soil fertility and gases for thermal application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understanding the mechanism of catalytic fast pyrolysis by unveiling reactive intermediates in heterogeneous catalysis

NASA Astrophysics Data System (ADS)

Hemberger, Patrick; Custodis, Victoria B. F.; Bodi, Andras; Gerber, Thomas; van Bokhoven, Jeroen A.

2017-06-01

Catalytic fast pyrolysis is a promising way to convert lignin into fine chemicals and fuels, but current approaches lack selectivity and yield unsatisfactory conversion. Understanding the pyrolysis reaction mechanism at the molecular level may help to make this sustainable process more economic. Reactive intermediates are responsible for product branching and hold the key to unveiling these mechanisms, but are notoriously difficult to detect isomer-selectively. Here, we investigate the catalytic pyrolysis of guaiacol, a lignin model compound, using photoelectron photoion coincidence spectroscopy with synchrotron radiation, which allows for isomer-selective detection of reactive intermediates. In combination with ambient pressure pyrolysis, we identify fulvenone as the central reactive intermediate, generated by catalytic demethylation to catechol and subsequent dehydration. The fulvenone ketene is responsible for the phenol formation. This technique may open unique opportunities for isomer-resolved probing in catalysis, and holds the potential for achieving a mechanistic understanding of complex, real-life catalytic processes.

Understanding the mechanism of catalytic fast pyrolysis by unveiling reactive intermediates in heterogeneous catalysis

PubMed Central

Hemberger, Patrick; Custodis, Victoria B. F.; Bodi, Andras; Gerber, Thomas; van Bokhoven, Jeroen A.

2017-01-01

Catalytic fast pyrolysis is a promising way to convert lignin into fine chemicals and fuels, but current approaches lack selectivity and yield unsatisfactory conversion. Understanding the pyrolysis reaction mechanism at the molecular level may help to make this sustainable process more economic. Reactive intermediates are responsible for product branching and hold the key to unveiling these mechanisms, but are notoriously difficult to detect isomer-selectively. Here, we investigate the catalytic pyrolysis of guaiacol, a lignin model compound, using photoelectron photoion coincidence spectroscopy with synchrotron radiation, which allows for isomer-selective detection of reactive intermediates. In combination with ambient pressure pyrolysis, we identify fulvenone as the central reactive intermediate, generated by catalytic demethylation to catechol and subsequent dehydration. The fulvenone ketene is responsible for the phenol formation. This technique may open unique opportunities for isomer-resolved probing in catalysis, and holds the potential for achieving a mechanistic understanding of complex, real-life catalytic processes. PMID:28660882

Volatile Analysis by Pyrolysis of Regolith (Vapor) for Planetary Resource Prospecting

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Malespin, C. A.; Ten Kate, I. L.; Mcadam, A.; Getty, S. A.; Mumm, E.; Franz, H. B.; Southard, A. E.; Bleacher, J. E.; Mahaffy, P. R.

2016-01-01

Measuring the chemical composition of planetary bodies and their atmospheres is key to understanding the formation of the Solar System and the evolution of the planets and their moons. In situ volatile measurements enable a ground-truth assessment of the distribution and abundance of resources such as water-ice and oxygen, important for a sustained human presence on the Moon and beyond. The Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument is a compact pyrolysis mass spectrometer designed to detect volatiles released from solid samples that are heated to elevated temperatures and is one technique that should be considered for resource prospecting on the Moon, Mars, and asteroids.

Pyrolysis with staged recovery

DOEpatents

Green, Norman W.; Duraiswamy, Kandaswamy; Lumpkin, Robert E.; Winter, Bruce L.

1979-03-20

In a continuous process for recovery of values contained in a solid carbonaceous material, the carbonaceous material is comminuted and then subjected to flash pyrolysis in the presence of a particulate heat source fed over an overflow weir to form a pyrolysis product stream containing a carbon containing solid residue and volatilized hydrocarbons. After the carbon containing solid residue is separated from the pyrolysis product stream, values are obtained by condensing volatilized hydrocarbons. The particulate source of heat is formed by oxidizing carbon in the solid residue.

High-throughput differentiation of heparin from other glycosaminoglycans by pyrolysis mass spectrometry.

PubMed

Nemes, Peter; Hoover, William J; Keire, David A

2013-08-06

Sensors with high chemical specificity and enhanced sample throughput are vital to screening food products and medical devices for chemical or biochemical contaminants that may pose a threat to public health. For example, the rapid detection of oversulfated chondroitin sulfate (OSCS) in heparin could prevent reoccurrence of heparin adulteration that caused hundreds of severe adverse events including deaths worldwide in 2007-2008. Here, rapid pyrolysis is integrated with direct analysis in real time (DART) mass spectrometry to rapidly screen major glycosaminoglycans, including heparin, chondroitin sulfate A, dermatan sulfate, and OSCS. The results demonstrate that, compared to traditional liquid chromatography-based analyses, pyrolysis mass spectrometry achieved at least 250-fold higher sample throughput and was compatible with samples volume-limited to about 300 nL. Pyrolysis yielded an abundance of fragment ions (e.g., 150 different m/z species), many of which were specific to the parent compound. Using multivariate and statistical data analysis models, these data enabled facile differentiation of the glycosaminoglycans with high throughput. After method development was completed, authentically contaminated samples obtained during the heparin crisis by the FDA were analyzed in a blinded manner for OSCS contamination. The lower limit of differentiation and detection were 0.1% (w/w) OSCS in heparin and 100 ng/μL (20 ng) OSCS in water, respectively. For quantitative purposes the linear dynamic range spanned approximately 3 orders of magnitude. Moreover, this chemical readout was successfully employed to find clues in the manufacturing history of the heparin samples that can be used for surveillance purposes. The presented technology and data analysis protocols are anticipated to be readily adaptable to other chemical and biochemical agents and volume-limited samples.

Effects of RF plasma treatment on spray-pyrolyzed copper oxide films on silicon substrates

NASA Astrophysics Data System (ADS)

Madera, Rozen Grace B.; Martinez, Melanie M.; Vasquez, Magdaleno R., Jr.

2018-01-01

The effects of radio-frequency (RF) argon (Ar) plasma treatment on the structural, morphological, electrical and compositional properties of the spray-pyrolyzed p-type copper oxide films on n-type (100) silicon (Si) substrates were investigated. The films were successfully synthesized using 0.3 M copper acetate monohydrate sprayed on precut Si substrates maintained at 350 °C. X-ray diffraction revealed cupric oxide (CuO) with a monoclinic structure. An apparent improvement in crystallinity was realized after Ar plasma treatment, attributed to the removal of residues contaminating the surface. Scanning electron microscope images showed agglomerated monoclinic grains and revealed a reduction in size upon plasma exposure induced by the sputtering effect. The current-voltage characteristics of CuO/Si showed a rectifying behavior after Ar plasma exposure with an increase in turn-on voltage. Four-point probe measurements revealed a decrease in sheet resistance after plasma irradiation. Fourier transform infrared spectral analyses also showed O-H and C-O bands on the films. This work was able to produce CuO thin films via spray pyrolysis on Si substrates and enhancement in their properties by applying postdeposition Ar plasma treatment.

Methods and apparatuses for preparing upgraded pyrolysis oil

DOEpatents

Brandvold, Timothy A; Baird, Lance Awender; Frey, Stanley Joseph

2013-10-01

Methods and apparatuses for preparing upgraded pyrolysis oil are provided herein. In an embodiment, a method of preparing upgraded pyrolysis oil includes providing a biomass-derived pyrolysis oil stream having an original oxygen content. The biomass-derived pyrolysis oil stream is hydrodeoxygenated under catalysis in the presence of hydrogen to form a hydrodeoxygenated pyrolysis oil stream comprising a cyclic paraffin component. At least a portion of the hydrodeoxygenated pyrolysis oil stream is dehydrogenated under catalysis to form the upgraded pyrolysis oil.

An economic analysis of mobile pyrolysis for northern New Mexico forests.

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

Brady, Patrick D.; Brown, Alexander L.; Mowry, Curtis Dale

2011-12-01

In the interest of providing an economically sensible use for the copious small-diameter wood in Northern New Mexico, an economic study is performed focused on mobile pyrolysis. Mobile pyrolysis was selected for the study because transportation costs limit the viability of a dedicated pyrolysis plant, and the relative simplicity of pyrolysis compared to other technology solutions lends itself to mobile reactor design. A bench-scale pyrolysis system was used to study the wood pyrolysis process and to obtain performance data that was otherwise unavailable under conditions theorized to be optimal given the regional problem. Pyrolysis can convert wood to three mainmore » products: fixed gases, liquid pyrolysis oil and char. The fixed gases are useful as low-quality fuel, and may have sufficient chemical energy to power a mobile system, eliminating the need for an external power source. The majority of the energy content of the pyrolysis gas is associated with carbon monoxide, followed by light hydrocarbons. The liquids are well characterized in the historical literature, and have slightly lower heating values comparable to the feedstock. They consist of water and a mix of hundreds of hydrocarbons, and are acidic. They are also unstable, increasing in viscosity with time stored. Up to 60% of the biomass in bench-scale testing was converted to liquids. Lower ({approx}550 C) furnace temperatures are preferred because of the decreased propensity for deposits and the high liquid yields. A mobile pyrolysis system would be designed with low maintenance requirements, should be able to access wilderness areas, and should not require more than one or two people to operate the system. The techno-economic analysis assesses fixed and variable costs. It suggests that the economy of scale is an important factor, as higher throughput directly leads to improved system economic viability. Labor and capital equipment are the driving factors in the viability of the system. The break

Immobilized TiO2 nanoparticles produced by flame spray for photocatalytic water remediation

NASA Astrophysics Data System (ADS)

Bettini, Luca Giacomo; Diamanti, Maria Vittoria; Sansotera, Maurizio; Pedeferri, Maria Pia; Navarrini, Walter; Milani, Paolo

2016-08-01

Anatase/rutile mixed-phase titanium dioxide (TiO2) photocatalysts in the form of nanostructured powders with different primary particle size, specific surface area, and rutile content were produced from the gas-phase by flame spray pyrolysis (FSP) starting from an organic solution containing titanium (IV) isopropoxide as Ti precursor. Flame spray-produced TiO2 powders were characterized by means of X-ray diffraction, Raman spectroscopy, and BET measurements. As-prepared powders were mainly composed of anatase crystallites with size ranging from 7 to 15 nm according to the synthesis conditions. TiO2 powders were embedded in a multilayered fluoropolymeric matrix to immobilize the nanoparticles into freestanding photocatalytic membranes. The photocatalytic activity of the TiO2-embedded membranes toward the abatement of hydrosoluble organic pollutants was evaluated employing the photodegradation of rhodamine B in aqueous solution as test reaction. The photoabatement rate of best performing membranes significantly overcomes that of membranes produced by the same method and incorporating commercial P25-TiO2.

Integration of pyrolysis and anaerobic digestion--use of aqueous liquor from digestate pyrolysis for biogas production.

PubMed

Hübner, Tobias; Mumme, Jan

2015-05-01

Anaerobic digestion of aqueous pyrolysis liquor derived from pyrolysis of solid digestate was tested in batch mode using an un-adapted inoculum. Three pyrolysis liquors produced at 330°C, 430°C and 530°C in four COD-based concentrations of 3, 6, 12 and 30 g L(-1) were investigated. The three lower concentrations showed considerable biogas production, whereas the 30 g L(-1) dosage caused process inhibition. The highest methane yield of 199.1±18.5 mL g(COD)(-1) (COD removal: 56.9±5.3%) was observed for the 330°C pyrolysis liquor, followed by the 430°C sample with only slightly lower values. The 530°C sample dropped to a yield of 129.3±19.7 mL g(COD)(-1) (COD removal: 36.9±5.6%). Most VOCs contained in the pyrolysis liquor (i.e. furfural, phenol, catechol, guaiacol, and levoglucosan) were reduced below detection limit (cresol by 10-60%). Consequently, integrated pyrolysis and anaerobic digestion in addition to thermochemical conversion of digestate also promises bioconversion of pyrolysis liquors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spray deposition of highly transparent fluorine doped cadmium oxide thin films

NASA Astrophysics Data System (ADS)

Deokate, R. J.; Pawar, S. M.; Moholkar, A. V.; Sawant, V. S.; Pawar, C. A.; Bhosale, C. H.; Rajpure, K. Y.

2008-01-01

The cadmium oxide (CdO) and F:CdO films have been deposited by spray pyrolysis method using cadmium acetate and ammonium fluoride as precursors for Cd and F ions, respectively. The effect of temperature and F doping on the structural, morphological, optical and Hall effect properties of sprayed CdO thin films was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption and electrical measurement techniques. TGA and DTA studies, indicates the formation of CdO by decomposition of cadmium acetate after 250 °C. XRD patterns reveal that samples are polycrystalline with cubic structure and exhibits (2 0 0) preferential orientation. Considerable broading of (2 0 0) peak, simultaneous shifting of corresponding Bragg's angle have been observed with respect to F doping level. SEM and AFM show the heterogeneous distribution of cubical grains all over the substrate, which are randomly distributed. F doping shifts the optical gap along with the increase in the transparency of CdO films. The Hall effect measurement indicates that the resistivity and mobility decrease up to 4% F doping.

Processing of uranium oxide and silicon carbide based fuel using polymer infiltration and pyrolysis

NASA Astrophysics Data System (ADS)

Singh, Abhishek K.; Zunjarrao, Suraj C.; Singh, Raman P.

2008-09-01

Ceramic composite pellets consisting of uranium oxide, UO 2, contained within a silicon carbide matrix, were fabricated using a novel processing technique based on polymer infiltration and pyrolysis (PIP). In this process, particles of depleted uranium oxide, in the form of U 3O 8, were dispersed in liquid allylhydridopolycarbosilane (AHPCS), and subjected to pyrolysis up to 900 °C under a continuous flow of ultra high purity argon. The pyrolysis of AHPCS, at these temperatures, produced near-stoichiometric amorphous silicon carbide ( a-SiC). Multiple polymer infiltration and pyrolysis (PIP) cycles were performed to minimize open porosity and densify the silicon carbide matrix. Analytical characterization was conducted to investigate chemical interaction between U 3O 8 and SiC. It was observed that U 3O 8 reacted with AHPCS during the very first pyrolysis cycle, and was converted to UO 2. As a result, final composition of the material consisted of UO 2 particles contained in an a-SiC matrix. The physical and mechanical properties were also quantified. It is shown that this processing scheme promotes uniform distribution of uranium fuel source along with a high ceramic yield of the parent matrix.

Quantum chemical investigation of the primary thermal pyrolysis reactions of the sodium carboxylate group in a brown coal model.

PubMed

Li, Jian; Zhang, Baisheng; Zhang, Zhiqiang; Yan, Kefeng; Kang, Lixun

2014-12-01

The primary pyrolysis mechanisms of the sodium carboxylate group in sodium benzoate-used as a model compound of brown coal-were studied by performing quantum chemical computations using B3LYP and the CBS method. Various possible reaction pathways involving reactions such as unimolecular and bimolecular decarboxylation and decarbonylation, crosslinking, and radical attack in the brown coal matrix were explored. Without the participation of reactive radicals, unimolecular decarboxylation to release CO2 was calculated to be the most energetically favorable primary reaction pathway at the B3LYP/6-311+G (d, p) level of theory, and was also found to be more energetically favorable than decarboxylation of an carboxylic acid group. When CBS-QBS results were included, crosslinking between the sodium carboxylate group and the carboxylic acid and the decarboxylation of the sodium carboxylate group (catalyzed by the phenolic hydroxyl group) were found to be possible; this pathway competes with unimolecular decarboxylation of the sodium carboxylate group. Provided that H and CH3 radicals are present in the brown coal matrix and can access the sodium carboxylate group, accelerated pyrolysis of the sodium carboxylate group becomes feasible, leading to the release of an Na atom or an NaCO2 radical at the B3LYP/6-311+G (d, p) or CBS-QB3 level of theory, respectively.

Pyrolysis with cyclone burner

DOEpatents

Green, Norman W.; Duraiswamy, Kandaswamy; Lumpkin, Robert E.

1978-07-25

In a continuous process for recovery of values contained in a solid carbonaceous material, the carbonaceous material is comminuted and then subjected to flash pyrolysis in the presence of a particulate heat source over an overflow weir to form a pyrolysis product stream containing a carbon containing solid residue and volatilized hydrocarbons. After the carbon containing solid residue is separated from the pyrolysis product stream, values are obtained by condensing volatilized hydrocarbons. The particulate source of heat is formed by oxidizing carbon in the solid residue and separating out the fines.

Catalytic biomass pyrolysis process

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

Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.

Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

CFD Modeling of a Laser-Induced Ethane Pyrolysis in a Wall-less Reactor

NASA Astrophysics Data System (ADS)

Stadnichenko, Olga; Snytnikov, Valeriy; Yang, Junfeng; Matar, Omar

2014-11-01

Ethylene, as the most important feedstock, is widely used in chemical industry to produce various rubbers, plastics and synthetics. A recent study found the IR-laser irradiation induced ethane pyrolysis yields 25% higher ethylene production rates compared to the conventional steam cracking method. Laser induced pyrolysis is initiated by the generation of radicals upon heating of the ethane, then, followed by ethane/ethylene autocatalytic reaction in which ethane is converted into ethylene and other light hydrocarbons. This procedure is governed by micro-mixing of reactants and the feedstock residence time in reactor. Under mild turbulent conditions, the turbulence enhances the micro-mixing process and allows a high yield of ethylene. On the other hand, the high flow rate only allows a short residence time in the reactor which causes incomplete pyrolysis. This work attempts to investigate the interaction between turbulence and ethane pyrolysis process using large eddy simulation method. The modelling results could be applied to optimize the reactor design and operating conditions. Skolkovo Foundation through the UNIHEAT Project.

Formation characteristics of aerosol particles from pulverized coal pyrolysis in high-temperature environments.

PubMed

Chen, Wei-Hsin; Du, Shan-Wen; Yang, Hsi-Hsien; Wu, Jheng-Syun

2008-05-01

The formation characteristics of aerosol particles from pulverized coal pyrolysis in high temperatures are studied experimentally. By conducting a drop-tube furnace, fuel pyrolysis processes in industrial furnaces are simulated in which three different reaction temperatures of 1000, 1200, and 1400 degrees C are considered. Experimental observations indicate that when the reaction temperature is 1000 degrees C, submicron particles are produced, whereas the particle size is dominated by nanoscale for the temperature of 1400 degrees C. Thermogravimetric analysis of the aerosol particles stemming from the pyrolysis temperature of 1000 degrees C reveals that the thermal behavior of the aerosol is characterized by a three-stage reaction with increasing heating temperature: (1) a volatile-reaction stage, (2) a weak-reaction stage, and (3) a soot-reaction stage. However, with the pyrolysis temperature of 1400 degrees C, the volatile- and weak-reaction stages almost merge together and evolve into a chemical-frozen stage. The submicron particles (i.e., 1000 degrees C) are mainly composed of volatiles, tar, and soot, with the main component of the nanoscale particles (i.e., 1400 degrees C) being soot. The polycyclic aromatic hydrocarbons (PAHs) contained in the aerosols are also analyzed. It is found that the PAH content in generated aerosols decreases dramatically as the pyrolysis temperature increases.

Thermal Spraying of Bioactive Polymer Coatings for Orthopaedic Applications

NASA Astrophysics Data System (ADS)

Chebbi, A.; Stokes, J.

2012-06-01

Flame sprayed biocompatible polymer coatings, made of biodegradable and non-biodegradable polymers, were investigated as single coatings on titanium and as top coatings on plasma sprayed Hydroxyapatite. Biocompatible polymers can act as drug carriers for localized drug release following implantation. The polymer matrix consisted of a biodegradable polymer, polyhydroxybutyrate 98%/ polyhydroxyvalerate 2% (PHBV) and a non-biodegradable polymer, polymethylmethacrylate (PMMA). Screening tests were performed to determine the suitable range of spraying parameters, followed by a Design of Experiments study to determine the effects of spraying parameters on coating characteristics (thickness, roughness, adhesion, wettability), and to optimize the coating properties accordingly. Coatings characterization showed that optimized flame sprayed biocompatible polymers underwent little chemical degradation, did not produce acidic by-products in vitro, and that cells proliferated well on their surface.

Rapid identification of bacteria with miniaturized pyrolysis/GC analysis

NASA Astrophysics Data System (ADS)

Morgan, Catherine H.; Mowry, Curtis; Manginell, Ronald P.; Frye-Mason, Gregory C.; Kottenstette, Richard J.; Lewis, Patrick

2001-02-01

Identification of bacteria and other biological moieties finds a broad range of applications in the environmental, biomedical, agricultural, industrial, and military arenas. Linking these applications are biological markers such as fatty acids, whose mass spectral profiles can be used to characterize biological samples and to distinguish bacteria at the gram-type, genera, and even species level. Common methods of sample analysis require sample preparation that is both lengthy and labor intensive, especially for whole cell bacteria. The background technique relied on here utilizes chemical derivatization of fatty acids to the more volatile fatty acid methyl esters (FAMEs), which can be separated on a gas chromatograph column or input directly into a mass spectrometer. More recent publications demonstrate improved sample preparation time with in situ derivatization of whole bacterial samples using pyrolysis at the inlet; although much faster than traditional techniques, these systems still rely on bench-top analytical equipment and individual sample preparation. Development of a miniaturized pyrolysis/GC instrument by this group is intended to realize the benefits of FAME identification of bacteria and other biological samples while further facilitating sample handling and instrument portability. The technologies being fabricated and tested have the potential of achieving pyrolysis and FAME separation on a very small scale, with rapid detection time (1-10 min from introduction to result), and with a modular sample inlet. Performance results and sensor characterization will be presented for the first phase of instrument development, encompassing the microfabricated pyrolysis and gas chromatograph elements.

Deactivation of Multilayered MFI Nanosheet Zeolite during Upgrading of Biomass Pyrolysis Vapors

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

Xu, Mengze; Mukarakate, Calvin; Iisa, Kristiina

Here, the catalytic fast pyrolysis (CFP) of biomass is a promising technology for producing renewable transportation fuels and chemicals. MFI-type catalysts have shown promise for CFP because they produce gasoline range hydrocarbons from oxygenated pyrolysis compounds; however, rapid catalyst deactivation due to coking is one of the major technical barriers inhibiting the commercialization of this technology. Coke deposited on the surface of the catalysts blocks access to active sites in the micropores leading to rapid catalyst deactivation. Our strategy is to minimize rapid catalyst deactivation by adding mesoporosity through forming MFI nanosheet materials. The synthesized MFI nanosheet catalysts were fullymore » characterized and evaluated for cellulose pyrolysis vapor upgrading to produce olefins and aromatic hydrocarbons. The data obtained from pyrolysis-GCMS (py-GCMS), showed that fresh MFI nanosheets produced similar aromatic hydrocarbon and olefin yields compared to conventional HZSM-5. However, MFI nanosheets demonstrated a longer lifetime than HZSM-5 even though coke contents were also higher than for HZSM-5 because the mesopores enabled better accessibility to active acid sites. This conclusion was supported by results from post-reaction analysis of various spent catalysts collected at different points during the deactivation experiments.« less

New applications of X-ray tomography in pyrolysis of biomass: Biochar imaging

DOE PAGES

Jones, Keith; Ramakrishnan, Girish; Uchimiya, Minori; ...

2015-01-30

We report on the first ever use of non-destructive micrometer-scale synchrotron-computed microtomography (CMT) for biochar material characterization as a function of pyrolysis temperature. This innovative approach demonstrated an increase in micron-sized marcropore fraction of the Cotton Hull (CH) sample, resulting in up to 29% sample porosity. We have also found that initial porosity development occurred at low temperatures (below 350°C) of pyrolysis, consistent with chemical composition of CH. This innovative technique can be highly complementary to traditional BET measurements, considering that Barrett–Joyner–Halenda (BJH) analysis of pore size distribution cannot detect these macropores. Such information can be of substantial relevance tomore » environmental applications, given that water retention by biochars added to soils is controlled by macropore characteristic among the other factors. In addition, complementing our data with SEM, EDX, and XRF characterization techniques allowed us to develop a better understanding of evolution of biochar properties during its production, such presence of metals and initial morphological features of biochar before pyrolysis. These results have significant implications for using biochar as a soil additive and for clarifying the mechanisms of biofuel production by pyrolysis.« less

New applications of X-ray tomography in pyrolysis of biomass: Biochar imaging

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

Jones, Keith; Ramakrishnan, Girish; Uchimiya, Minori

We report on the first ever use of non-destructive micrometer-scale synchrotron-computed microtomography (CMT) for biochar material characterization as a function of pyrolysis temperature. This innovative approach demonstrated an increase in micron-sized marcropore fraction of the Cotton Hull (CH) sample, resulting in up to 29% sample porosity. We have also found that initial porosity development occurred at low temperatures (below 350°C) of pyrolysis, consistent with chemical composition of CH. This innovative technique can be highly complementary to traditional BET measurements, considering that Barrett–Joyner–Halenda (BJH) analysis of pore size distribution cannot detect these macropores. Such information can be of substantial relevance tomore » environmental applications, given that water retention by biochars added to soils is controlled by macropore characteristic among the other factors. In addition, complementing our data with SEM, EDX, and XRF characterization techniques allowed us to develop a better understanding of evolution of biochar properties during its production, such presence of metals and initial morphological features of biochar before pyrolysis. These results have significant implications for using biochar as a soil additive and for clarifying the mechanisms of biofuel production by pyrolysis.« less

Deactivation of Multilayered MFI Nanosheet Zeolite during Upgrading of Biomass Pyrolysis Vapors

DOE PAGES

Xu, Mengze; Mukarakate, Calvin; Iisa, Kristiina; ...

2017-05-02

Here, the catalytic fast pyrolysis (CFP) of biomass is a promising technology for producing renewable transportation fuels and chemicals. MFI-type catalysts have shown promise for CFP because they produce gasoline range hydrocarbons from oxygenated pyrolysis compounds; however, rapid catalyst deactivation due to coking is one of the major technical barriers inhibiting the commercialization of this technology. Coke deposited on the surface of the catalysts blocks access to active sites in the micropores leading to rapid catalyst deactivation. Our strategy is to minimize rapid catalyst deactivation by adding mesoporosity through forming MFI nanosheet materials. The synthesized MFI nanosheet catalysts were fullymore » characterized and evaluated for cellulose pyrolysis vapor upgrading to produce olefins and aromatic hydrocarbons. The data obtained from pyrolysis-GCMS (py-GCMS), showed that fresh MFI nanosheets produced similar aromatic hydrocarbon and olefin yields compared to conventional HZSM-5. However, MFI nanosheets demonstrated a longer lifetime than HZSM-5 even though coke contents were also higher than for HZSM-5 because the mesopores enabled better accessibility to active acid sites. This conclusion was supported by results from post-reaction analysis of various spent catalysts collected at different points during the deactivation experiments.« less

Integrated biomass pyrolysis with organic Rankine cycle for power generation

NASA Astrophysics Data System (ADS)

Nur, T. B.; Syahputra, A. W.

2018-02-01

The growing interest on Organic Rankine Cycle (ORC) application to produce electricity by utilizing biomass energy sources are increasingly due to its successfully used to generate power from waste heat available in industrial processes. Biomass pyrolysis is one of the thermochemical technologies for converting biomass into energy and chemical products consisting of liquid bio-oil, solid biochar, and pyrolytic gas. In the application, biomass pyrolysis can be divided into three main categories; slow, fast and flash pyrolysis mainly aiming at maximizing the products of bio-oil or biochar. The temperature of synthesis gas generated during processes can be used for Organic Rankine Cycle to generate power. The heat from synthesis gas during pyrolysis processes was transfer by thermal oil heater to evaporate ORC working fluid in the evaporator unit. In this study, the potential of the palm oil empty fruit bunch, palm oil shell, and tree bark have been used as fuel from biomass to generate electricity by integrated with ORC. The Syltherm-XLT thermal oil was used as the heat carrier from combustion burner, while R245fa was used as the working fluid for ORC system. Through Aspen Plus, this study analyses the influences on performance of main thermodynamic parameters, showing the possibilities of reaching an optimum performance for different working conditions that are characteristics of different design parameters.

Quality characteristic of spray-drying egg white powders.

PubMed

Ma, Shuang; Zhao, Songning; Zhang, Yan; Yu, Yiding; Liu, Jingbo; Xu, Menglei

2013-10-01

Spray drying is a useful method for developing egg process and utilization. The objective of this study was to evaluate effects on spray drying condition of egg white. The optimized conditions were spraying flow 22 mL/min, feeding temperature 39.8 °C and inlet-air temperature 178.2 °C. Results of sulfydryl (SH) groups measurement indicated conformation structure have changed resulting in protein molecule occur S-S crosslinking phenomenon when heating. It led to free SH content decreased during spray drying process. There was almost no change of differential scanning calorimetry between fresh egg white and spray-drying egg white powder (EWP). For a given protein, the apparent SH reactivity is in turn influenced by the physico-chemical characteristics of the reactant. The phenomenon illustrated the thermal denaturation of these proteins was unrelated to their free SH contents. Color measurement was used to study browning level. EWP in optimized conditions revealed insignificant brown stain. Swelling capacity and scanning electron micrograph both proved well quality characteristic of spray-drying EWP. Results suggested spray drying under the optimized conditions present suitable and alternative method for egg processing industrial implementation. Egg food industrialization needs new drying method to extend shelf-life. The purpose of the study was to provide optimal process of healthy and nutritional instant spray-drying EWP and study quality characteristic of spray-drying EWP.

Recovery of materials from waste printed circuit boards by vacuum pyrolysis and vacuum centrifugal separation.

PubMed

Zhou, Yihui; Wu, Wenbiao; Qiu, Keqiang

2010-11-01

In this research, a two-step process consisting of vacuum pyrolysis and vacuum centrifugal separation was employed to treat waste printed circuit boards (WPCBs). Firstly, WPCBs were pyrolysed under vacuum condition at 600 °C for 30 min in a lab-scale reactor. Then, the obtained pyrolysis residue was heated under vacuum until the solder was melted, and then the molten solder was separated from the pyrolysis residue by the centrifugal force. The results of vacuum pyrolysis showed that the type-A of WPCBs (the base plates of which was made from cellulose paper reinforced phenolic resin) pyrolysed to form an average of 67.97 wt.% residue, 27.73 wt.% oil, and 4.30 wt.% gas; and pyrolysis of the type-B of WPCBs (the base plates of which was made from glass fiber reinforced epoxy resin) led to an average mass balance of 72.20 wt.% residue, 21.45 wt.% oil, and 6.35 wt.% gas. The results of vacuum centrifugal separation showed that the separation of solder was complete when the pyrolysis residue was heated at 400 °C, and the rotating drum was rotated at 1200 rpm for 10 min. The pyrolysis oil and gas can be used as fuel or chemical feedstock after treatment. The pyrolysis residue after solder separation contained various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The recovered solder can be reused directly and it can also be a good resource of lead and tin for refining. Copyright © 2010 Elsevier Ltd. All rights reserved.

Natural Catalysts for Molten Cellulose Pyrolysis to Targeted Bio-Oils

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

Dauenhauer, Paul J.

2017-06-02

Catalysis of biomass biopolymer cellulose by alkaline earth metals is a fundamental chemistry relevant to energy processes including combustion, pyrolysis and gasification. In this work, the catalytic decomposition of cellulose by calcium ions was evaluated at high temperature (400-500°C) to elucidate the chemical mechanisms leading to the formation of volatile organic compounds.

Touch Spray Mass Spectrometry for In Situ Analysis of Complex Samples

PubMed Central

Kerian, Kevin S.; Jarmusch, Alan K.; Cooks, R. Graham

2014-01-01

Touch spray, a spray-based ambient in-situ ionization method, uses a small probe, e.g. a teasing needle to pick up sample and the application of voltage and solvent to cause field-induced droplet emission. Compounds extracted from the microsample are incorporated into the sprayed micro droplets. Performance tests include disease state of tissue, microorganism identification, and therapeutic drug quantitation. Chemical derivatization is performed simultaneously with ionization. PMID:24756256

Flash Pyrolysis and Fractional Pyrolysis of Oleaginous Biomass in a Fluidized-bed Reactor

NASA Astrophysics Data System (ADS)

Urban, Brook

Thermochemical conversion methods such as pyrolysis have the potential for converting diverse biomass feedstocks into liquid fuels. In particular, bio-oil yields can be maximized by implementing flash pyrolysis to facilitate rapid heat transfer to the solids along with short vapor residence times to minimize secondary degradation of bio-oils. This study first focused on the design and construction of a fluidized-bed flash pyrolysis reactor with a high-efficiency bio-oil recovery unit. Subsequently, the reactor was used to perform flash pyrolysis of soybean pellets to assess the thermochemical conversion of oleaginous biomass feedstocks. The fluidized bed reactor design included a novel feed input mechanism through suction created by flow of carrier gas through a venturi which prevented plugging problems that occur with a more conventional screw feeders. In addition, the uniquely designed batch pyrolysis unit comprised of two tubes of dissimilar diameters. The bottom section consisted of a 1" tube and was connected to a larger 3" tube placed vertically above. At the carrier gas flow rates used in these studies, the feed particles remained fluidized in the smaller diameter tube, but a reduction in carrier gas velocity in the larger diameter "disengagement chamber" prevented the escape of particles into the condensers. The outlet of the reactor was connected to two Allihn condensers followed by an innovative packed-bed dry ice condenser. Due to the high carrier gas flow rates in fluidized bed reactors, bio-oil vapors form dilute aerosols upon cooling which that are difficult to coalesce and recover by traditional heat exchange condensers. The dry ice condenser provided high surface area for inertial impaction of these aerosols and also allowed easy recovery of bio-oils after natural evaporation of the dry ice at the end of the experiments. Single step pyrolysis was performed between 250-610°C with a vapor residence time between 0.3-0.6s. At 550°C or higher, 70% of

Nanoparticles by spray drying using innovative new technology: the Büchi nano spray dryer B-90.

PubMed

Li, Xiang; Anton, Nicolas; Arpagaus, Cordin; Belleteix, Fabrice; Vandamme, Thierry F

2010-10-15

Spray drying technology is widely known and used to transform liquids (solutions, emulsions, suspension, slurries, pastes or even melts) into solid powders. Its main applications are found in the food, chemical and materials industries to enhance ingredient conservation, particle properties, powder handling and storage etc. However, spray drying can also be used for specific applications in the formulation of pharmaceuticals for drug delivery (e.g. particles for pulmonary delivery). Büchi is a reference in the development of spray drying technology, notably for laboratory scale devices. This study presents the Nano Spray Dryer B-90, a revolutionary new sprayer developed by Büchi, use of which can lower the size of the produced dried particles by an order of magnitude attaining submicron sizes. In this paper, results are presented with a panel of five representative polymeric wall materials (arabic gum, whey protein, polyvinyl alcohol, modified starch, and maltodextrin) and the potentials to encapsulate nano-emulsions, or to formulate nano-crystals (e.g. from furosemide) are also shown. Copyright © 2010 Elsevier B.V. All rights reserved.

Bringing the ocean into the laboratory to probe the chemical complexity of sea spray aerosol

PubMed Central

Prather, Kimberly A.; Bertram, Timothy H.; Grassian, Vicki H.; Deane, Grant B.; Stokes, M. Dale; DeMott, Paul J.; Aluwihare, Lihini I.; Palenik, Brian P.; Azam, Farooq; Seinfeld, John H.; Moffet, Ryan C.; Molina, Mario J.; Cappa, Christopher D.; Geiger, Franz M.; Roberts, Gregory C.; Russell, Lynn M.; Ault, Andrew P.; Baltrusaitis, Jonas; Collins, Douglas B.; Corrigan, Craig E.; Cuadra-Rodriguez, Luis A.; Ebben, Carlena J.; Forestieri, Sara D.; Guasco, Timothy L.; Hersey, Scott P.; Kim, Michelle J.; Lambert, William F.; Modini, Robin L.; Mui, Wilton; Pedler, Byron E.; Ruppel, Matthew J.; Ryder, Olivia S.; Schoepp, Nathan G.; Sullivan, Ryan C.; Zhao, Defeng

2013-01-01

The production, size, and chemical composition of sea spray aerosol (SSA) particles strongly depend on seawater chemistry, which is controlled by physical, chemical, and biological processes. Despite decades of studies in marine environments, a direct relationship has yet to be established between ocean biology and the physicochemical properties of SSA. The ability to establish such relationships is hindered by the fact that SSA measurements are typically dominated by overwhelming background aerosol concentrations even in remote marine environments. Herein, we describe a newly developed approach for reproducing the chemical complexity of SSA in a laboratory setting, comprising a unique ocean-atmosphere facility equipped with actual breaking waves. A mesocosm experiment was performed in natural seawater, using controlled phytoplankton and heterotrophic bacteria concentrations, which showed SSA size and chemical mixing state are acutely sensitive to the aerosol production mechanism, as well as to the type of biological species present. The largest reduction in the hygroscopicity of SSA occurred as heterotrophic bacteria concentrations increased, whereas phytoplankton and chlorophyll-a concentrations decreased, directly corresponding to a change in mixing state in the smallest (60–180 nm) size range. Using this newly developed approach to generate realistic SSA, systematic studies can now be performed to advance our fundamental understanding of the impact of ocean biology on SSA chemical mixing state, heterogeneous reactivity, and the resulting climate-relevant properties. PMID:23620519

Understanding the stability of pyrolysis tars from biomass in a view point of free radicals.

PubMed

He, Wenjing; Liu, Qingya; Shi, Lei; Liu, Zhenyu; Ci, Donghui; Lievens, Caroline; Guo, Xiaofen; Liu, Muxin

2014-03-01

Fast pyrolysis of biomass has attracted increasing attention worldwide to produce bio-tars that can be upgraded into liquid fuels and chemicals. However, the bio-tars are usually poor in quality and stability and are difficult to be upgraded. To better understand the nature of the bio-tars, this work reveals radical concentration of tars derived from pyrolysis of two kinds of biomass. The tars were obtained by condensing the pyrolysis volatiles in 3s. It shows that the tars contain large amounts of radicals, at a level of 10(16)spins/g, and are able to generate more radicals at temperatures of 573K or higher, reaching a level of 10(19)spins/g at 673K in less than 30min. The radical generation in the tar samples is attributed to the formation of THF insoluble matters (coke), which also contain radicals. The radical concentrations of the aqueous liquids obtained in pyrolysis are also studied. Copyright © 2014 Elsevier Ltd. All rights reserved.

40 CFR 721.10579 - Carbon black derived from the pyrolysis of rubber tire shreds (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Carbon black derived from the pyrolysis of rubber tire shreds (generic). 721.10579 Section 721.10579 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical...

Fast Pyrolysis of Poplar Using a Captive Sample Reactor: Effects of Inorganic Salts on Primary Pyrolysis Products

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

Mukarakate, C.; Robichaud, D.; Donohoe, B.

2012-01-01

We have constructed a captive sample reactor (CSR) to study fast pyrolysis of biomass. The reactor uses a stainless steel wire mesh to surround biomass materials with an isothermal environment by independent controlling of heating rates and pyrolysis temperatures. The vapors produced during pyrolysis are immediately entrained and transported in He carrier gas to a molecular beam mass spectrometer (MBMS). Formation of secondary products is minimized by rapidly quenching the sample support with liquid nitrogen. A range of alkali and alkaline earth metal (AAEM) and transition metal salts were tested to study their effect on composition of primary pyrolysis products.more » Multivariate curve resolution (MCR) analysis of the MBMS data shows that transition metal salts enhance pyrolysis of carbohydrates and AAEM salts enhances pyrolysis of lignin. This was supported by performing similar separate studies on cellulose, hemicellulose and extracted lignin. The effect of salts on char formation is also discussed.« less

Formate-assisted pyrolysis

DOEpatents

DeSisto, William Joseph; Wheeler, Marshall Clayton; van Heiningen, Adriaan R. P.

2015-03-17

The present invention provides, among other thing, methods for creating significantly deoxygenated bio-oils form biomass including the steps of providing a feedstock, associating the feedstock with an alkali formate to form a treated feedstock, dewatering the treated feedstock, heating the dewatered treated feedstock to form a vapor product, and condensing the vapor product to form a pyrolysis oil, wherein the pyrolysis oil contains less than 30% oxygen by weight.

Synthesis of Zn1- x Co x Al2O4 Spinel Nanoparticles by Liquid-Feed Flame Spray Pyrolysis: Ceramic Pigments Application

NASA Astrophysics Data System (ADS)

Betancur Granados, Natalia; Yi, Eongyu; Laine, Richard M.; Restrepo Baena, Oscar Jaime

2016-01-01

Zn1- x Co x Al2O4 ( x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) spinel nanoparticles were synthesized by a liquid-feed flame spray pyrolysis (LF-FSP) method by combusting metallorganic precursor solutions to produce nanopowders with precise composition control. The precursor solutions were aerosolized into a methane/oxygen flame where it was combusted in an oxygen-rich environment to result in nanopowders at a single step. The nanopowders were analyzed by x-ray diffraction, Fourier transform infrared spectroscopy, colorimetry, field emission scanning electron microscopy, transmission electron microscopy, and BET (Brunauer-Emmett-Teller) N2 adsorption. Results show formation of spherical nanopowders with specific surface areas of 42 m2/g to 50 m2/g, which correspond to average particle sizes of 26 nm to 31 nm. Single-phase materials were obtained with a high control of composition, which indicates that LF-FSP is an excellent method to produce mixed-metal oxides for applications in which powder homogeneity is crucial. The products were evaluated for ceramic pigment application, where the ratio of Zn to Co was gradually changed to observe the color change in the structure with the increase of cobalt concentration. The resulting pigments were calcined at 1200°C, which aimed to identify the color stability after a high-temperature process, whereby the colors were measured using the color space CIE L*a*b* under standardized light, D65. Finally, the powders were tested for ceramic decoration using transparent glazes and ceramic bodies. The application was carried out at 1250°C to evaluate the color performance after a decoration process.

Catalytic conversion of biomass pyrolysis-derived compounds with chemical liquid deposition (CLD) modified ZSM-5.

PubMed

Zhang, Huiyan; Luo, Mengmeng; Xiao, Rui; Shao, Shanshan; Jin, Baosheng; Xiao, Guomin; Zhao, Ming; Liang, Junyu

2014-03-01

Chemical liquid deposition (CLD) with KH550, TEOS and methyl silicone oil as the modifiers was used to modify ZSM-5 and deposit its external acid sites. The characteristics of modified catalysts were tested by catalytic conversion of biomass pyrolysis-derived compounds. The effects of different modifying conditions (deposited amount, temperature, and time) on the product yields and selectivities were investigated. The results show KH550 modified ZSM-5 (deposited amount of 4%, temperature of 20°C and time of 6h) produced the maximum yields of aromatics (24.5%) and olefins (16.5%), which are much higher than that obtained with original ZSM-5 catalyst (18.8% aromatics and 9.8% olefins). The coke yield decreased from 44.1% with original ZSM-5 to 26.7% with KH550 modified ZSM-5. The selectivities of low-molecule-weight hydrocarbons (ethylene and benzene) decreased, while that of higher molecule-weight hydrocarbons (propylene, butylene, toluene, and naphthalene) increased comparing with original ZSM-5. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development and application of a continuous fast microwave pyrolysis system for sewage sludge utilization.

PubMed

Zhou, Junwen; Liu, Shiyu; Zhou, Nan; Fan, Liangliang; Zhang, Yaning; Peng, Peng; Anderson, Erik; Ding, Kuan; Wang, Yunpu; Liu, Yuhuan; Chen, Paul; Ruan, Roger

2018-05-01

A continuous fast microwave-assisted pyrolysis system was designed, fabricated, and tested with sewage sludge. The system is equipped with continuous biomass feeding, mixing of biomass and microwave absorbent, and separated catalyst upgrading. The effect of the sludge pyrolysis temperature (450, 500, 550, and 600 °C) on the products yield, distribution and potentially energy recovery were investigated. The physical, chemical, and energetic properties of the raw sewage sludge and bio-oil, char and gas products obtained were analyzed using elemental analyzer, GC-MS, Micro-GC, SEM and ICP-OES. While the maximum bio-oil yield of 41.39 wt% was obtained at pyrolysis temperature of 550 °C, the optimal pyrolysis temperature for maximum overall energy recovery was 500 °C. The absence of carrier gas in the process may be responsible for the high HHV of gas products. This work could provide technical support for microwave-assisted system scale-up and sewage sludge utilization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nickel doping effect on properties of sprayed In2S3 films

NASA Astrophysics Data System (ADS)

Kraini, M.; Bouguila, N.; El Ghoul, J.

2018-03-01

Nickel doped In2S3 films have been prepared by the chemical spray pyrolysis technique at 350 °C on glass substrates. The Ni doping level was changed by varying Ni:In molar ratio from 0 to 4% in solution. The structural studies reveal that the Ni-doped In2S3 films are polycrystalline and exhibit a cubic structure. As the Ni:In molar ratio increases, the crystallite size decreases from 27.5 to 23 nm and RMS roughness values increase from 12 to 18 nm, respectively. The presence of Ni in the deposited films was confirmed by energy dispersive spectroscopy. Raman studies show different peaks related to In2S3 phase and do not reveal any secondary phases of In-Ni and Ni-S. The transmission coefficient is about 70-55% in the visible region and 85-75% in near-infrared region. The band gap energy increases from 2.66 to 2.82 eV for direct transitions with the increase of Ni:In ratio from 0 to 4%. The refractive index values of In2S3:Ni thin films decrease from 2.46 to 2.40 and the extinction coefficient values are in the range 0.01-0.20.

Bird mortality after spraying for Dutch elm disease with DDT

USGS Publications Warehouse

Wurster, C.F.; Wurster, D.H.; Strickland, W.N.

1965-01-01

In Hanover, New Hampshire, where elms were sprayed with DDT, 151 dead birds were found; 10 dead birds were found in Norwich, Vermont, where no DDT was used. Chemical analyses of dead birds, observation of symptoms of DDT poisoning, and a population decline after spraying all indicate severe mortality among certain species in Hanover.

Deposition and characterization of spray pyrolysed p-type Cu2SnS3 thin film for potential absorber layer of solar cell

NASA Astrophysics Data System (ADS)

Thiruvenkadam, S.; Sakthi, P.; Prabhakaran, S.; Chakravarty, Sujay; Ganesan, V.; Rajesh, A. Leo

2018-06-01

Thin film of ternary Cu2SnS3 (CTS), a potential absorber layer for solar cells was successfully deposited by chemical spray pyrolysis technique. The GIXRD pattern revealed that the film having tetragonal Cu2SnS3 phase with the preferential orientation along (112), (200), (220) and (312) plane and it is further confirmed using Raman spectroscopy by the existence of Raman peak at 320 cm-1. Atomic Force Microscopy (AFM) was used to estimate the surface roughness of 28.8 nm. The absorption coefficient was found to be greater than the order of 105 cm-1 and bandgap of 1.70 eV. Hall effect measurement indicates the p type nature of the film with a hole concentration of 1.03 × 1016cm-3 and a hall mobility of 404 cm2/V. The properties of CTS thin film confirmed suitable to be a potential absorber layer material for photovoltaic applications.

Shape matters: Cr(VI) removal using iron nanoparticle impregnated 1-D vs 2-D carbon nanohybrids prepared by ultrasonic spray pyrolysis

NASA Astrophysics Data System (ADS)

Masud, Arvid; Cui, Yanbin; Atkinson, John D.; Aich, Nirupam

2018-03-01

Iron nanoparticles (Fe NPs) are used for treating water contaminated with metals or organic compounds. One-dimensional (1-D) carbon nanotubes (CNTs) and two-dimensional (2-D) graphenes act as useful nanocarbon (NC) supports for Fe NPs by resisting aggregation and enhancing adsorption and redox activity. However, no study showed how shape difference between tubular CNT and planar graphene structures dictates the physicochemical properties and pollutant removal potential of their iron-based nanohybrids. In this work, ultrasonic spray pyrolysis was used to continuously prepare Fe-CNT and Fe-rGO nanohybrids. Both NC shape and Fe/NC ratio influenced Fe NP size, loading, and oxidation states. High Fe content (precursor Fe/NC mass ratio = 2) resulted Fe NPs with diameters of 30.97 ± 7.00 and 24.11 ± 4.42 nm for Fe-CNT and Fe-rGO, respectively; however, low Fe content (Fe/NC = 0.2) provided more uniformly dispersed Fe NPs of 15.65 ± 3.06 and 9.67 ± 1.49 nm, respectively, while unsupported Fe NPs were 285.71 ± 132.42 nm. The USP-derived nanohybrids, for the first time, were used for removal of pollutant, i.e., chromium (Cr(VI)) from aqueous media. Both CNT and rGO provided synergistic effects to significantly enhance Fe NPs' ability to remove Cr(VI); the effect was more pronounced in Fe-rGO than Fe-CNT and also for low Fe content in both cases. Fe-rGO with low Fe/NC ratio and smallest Fe NPs provided the highest Cr(VI) removal capacity (25 mg/g), which was a multifold improvement over bare Fe NPs and other synthesized nanohybrids (range 7-14 mg/g). Overall, 2-D rGO improved contaminant removal capacity of the nanohybrids more than 1-D CNT indicating towards shape effect of NC supports. [Figure not available: see fulltext.

Pyrolysis technologies for municipal solid waste: A review

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

Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn; Yin, Lijie; Wang, Huan

2014-12-15

Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis inmore » regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.« less

Venom-spraying behavior of the scorpion Parabuthus transvaalicus (Arachnida: Buthidae).

PubMed

Nisani, Zia; Hayes, William K

2015-06-01

Many animals use chemical squirting or spraying behavior as a defensive response. Some members of the scorpion genus Parabuthus (family Buthidae) can spray their venom. We examined the stimulus control and characteristics of venom spraying by Parabuthus transvaalicus to better understand the behavioral context for its use. Venom spraying occurred mostly, but not always, when the metasoma (tail) was contacted (usually grasped by forceps), and was absent during stinging-like thrusts of the metasoma apart from contact. Scorpions were significantly more likely to spray when contact was also accompanied by airborne stimuli. Sprays happened almost instantaneously following grasping by forceps (median=0.23s) as a brief (0.07-0.30s, mean=0.18s), fine stream (<5° arc) that was not directed toward the stimulus source; however, rapid independent movements of the metasoma and/or telson (stinger) often created a more diffuse spray, increasing the possibility of venom contact with the sensitive eyes of potential scorpion predators. Successive venom sprays varied considerably in duration and velocity. Collectively, these results suggest that venom spraying might be useful as an antipredator function and can be modulated based on threat. Copyright © 2015 Elsevier B.V. All rights reserved.

Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

PubMed

Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

2014-01-01

Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions. Copyright © 2014 John Wiley & Sons, Ltd.

Kinetic compensation effect in logistic distributed activation energy model for lignocellulosic biomass pyrolysis.

PubMed

Xu, Di; Chai, Meiyun; Dong, Zhujun; Rahman, Md Maksudur; Yu, Xi; Cai, Junmeng

2018-06-04

The kinetic compensation effect in the logistic distributed activation energy model (DAEM) for lignocellulosic biomass pyrolysis was investigated. The sum of square error (SSE) surface tool was used to analyze two theoretically simulated logistic DAEM processes for cellulose and xylan pyrolysis. The logistic DAEM coupled with the pattern search method for parameter estimation was used to analyze the experimental data of cellulose pyrolysis. The results showed that many parameter sets of the logistic DAEM could fit the data at different heating rates very well for both simulated and experimental processes, and a perfect linear relationship between the logarithm of the frequency factor and the mean value of the activation energy distribution was found. The parameters of the logistic DAEM can be estimated by coupling the optimization method and isoconversional kinetic methods. The results would be helpful for chemical kinetic analysis using DAEM. Copyright © 2018 Elsevier Ltd. All rights reserved.

Catalytic co-pyrolysis of cellulose and polypropylene over all-silica mesoporous catalyst MCM-41 and Al-MCM-41.

PubMed

Chi, Yongchao; Xue, Junjie; Zhuo, Jiankun; Zhang, Dahu; Liu, Mi; Yao, Qiang

2018-08-15

Fast pyrolysis is one of the most economical and efficient technologies to convert biomass to bio-oil and valuable chemical products. Co-pyrolysis with hydrogen rich materials such as plastics over zeolite catalysts is one of the significant solutions to various problems of bio-oil such as high oxygen content, low heat value and high acid content. This paper studied pyrolysis of cellulose and polypropylene (PP) separately and co-pyrolysis of cellulose and PP over MCM-41 and Al-MCM-41. The pyrolysis over different heating rates (10K/min, 20K/min, 30K/min) was studied by Thermogravimetry Analysis (TGA) and kinetic parameters were obtained by Coats-Redfern method and isoconversion method. TG and DTG data shows that the two catalysts advance the pyrolysis reaction of PP significantly and reduce its peak temperature of DTG curve from 458°C to 341°C. The activation energy of pyrolysis of PP also has a remarkable reduction over the two catalysts. Py-GC/MS method was used to obtain the product distribution of pyrolysis of cellulose and PP separately and co-pyrolysis of cellulose and PP over MCM-41 and Al-MCM-41 at constant temperature of 650°C. Experiment results proved that co-pyrolysis with PP bring significant changes to the product distribution of cellulose. Oxygenated compounds such as furans are decreased, while yields of olefins and aromatics increase greatly. The yield of furans increases with the catalysis of MCM-41 as for the pyrolysis of cellulose and co-pyrolysis, while the yield of olefins and aromatics both experience significant growth over Al-MCM-41, which can be explained by the abundant acid centers in Al-MCM-41. Copyright © 2018 Elsevier B.V. All rights reserved.

Valorization of Rhizoclonium sp. algae via pyrolysis and catalytic pyrolysis.

PubMed

Casoni, Andrés I; Zunino, Josefina; Piccolo, María C; Volpe, María A

2016-09-01

The valorization of Rhizoclonium sp. algae through pyrolysis for obtaining bio-oils is studied in this work. The reaction is carried out at 400°C, at high contact time. The bio-oil has a practical yield of 35% and is rich in phytol. Besides, it is simpler than the corresponding to lignocellulosic biomass due to the absence of phenolic compounds. This property leads to a bio-oil relatively stable to storage. In addition, heterogeneous catalysts (Al-Fe/MCM-41, SBA-15 and Cu/SBA-15), in contact with algae during pyrolysis, are analyzed. The general trend is that the catalysts decrease the concentration of fatty alcohols and other high molecular weight products, since their mild acidity sites promote degradation reactions. Thus, the amount of light products increases upon the use of the catalysts. Particularly, acetol concentration in the bio-oils obtained from the catalytic pyrolysis with SBA-15 and Cu/SBA-15 is notably high. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of torrefaction pretreatment and catalytic pyrolysis on the pyrolysis poly-generation of pine wood.

PubMed

Chen, Dengyu; Li, Yanjun; Deng, Minsi; Wang, Jiayang; Chen, Miao; Yan, Bei; Yuan, Qiqiang

2016-08-01

Torrefaction of pine wood was performed in a tube furnace at three temperatures (220, 250, and 280°C) for 30min. Then catalytic pyrolysis of raw and torrefied pine wood was performed using HZSM-5 catalyst in a fixed-bed pyrolysis reactor at 550°C for 15min. Torrefaction pretreatment and catalytic pyrolysis have an very important effect on the yield, property, and energy distribution of pyrolysis products. The results showed that the yield of biochar rapidly increased, while that of bio-oil decreased with increasing torrefaction temperature. The oxy-compound content of bio-oil, such as acids and aldehydes, sharply decreased. However, the aromatic hydrocarbon content not only increased but also further promoted by HZSM-5 catalyst. With highest mass yields and energy yields, biochar was also the very important product of pyrolysis. The oxygen content in biomass was mainly removed in the form of CO2 and H2O, leading to increasing CO2 content in non-condensable gas. Copyright © 2016 Elsevier Ltd. All rights reserved.

The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

2010-10-01

The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2:Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2:Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

Effect of spray volume on the deposition, viability and infectivity of entomopathogenic nematodes in a foliar spray on vegetables.

PubMed

Brusselman, Eva; Beck, Bert; Pollet, Sabien; Temmerman, Femke; Spanoghe, Pieter; Moens, Maurice; Nuyttens, David

2012-10-01

Spray volume can influence the amount of free water on the leaf surface and subsequently the ability of entomopathogenic nematodes (EPNs) to move. In this study, an investigation was made of the effect of spray volume (548, 730 and 1095 L ha(-1) ) on the deposition, viability and infectivity of EPNs against Galleria mellonella on savoy cabbage, cauliflower and leek. Increasing spray volume decreased nematode deposition on 7.1 cm2 leek leaf discs at a 15° angle with the spray nozzle. Although the number of living nematodes observed on leek after 240 min of exposure was not significantly different between the low-volume application (548 L ha(-1) ) and the high-volume application (1095 L ha(-1) ), a greater infectivity was obtained in the latter application. The higher number of droplets deposited on the leek discs in the high-volume application may have stimulated nematode movement. No significant effect of spray volume was observed on the relative deposition of Steinernema carpocapsae on the bottom side of cauliflower and savoy cabbage leaf discs. In spite of the low S. carpocapsae deposition on the bottom side of the savoy cabbage discs, high infectivity was obtained against G. mellonella. Using the lowest spray volume on savoy cabbage, infectivity decreased with increasing exposure time, while infectivity was not affected by exposure time when a spray volume of 730 L ha(-1) or more was used. Spray volume is an important application parameter, as it affects nematode infectivity. Future research should investigate the effect of spray volume in the field and its influence on the effect of adjuvants. Copyright © 2012 Society of Chemical Industry.

Pyrolysis and co-pyrolysis of Laminaria japonica and polypropylene over mesoporous Al-SBA-15 catalyst

PubMed Central

2014-01-01

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N2 adsorption-desorption isotherms, and NH3 temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H2O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32 wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro-d-galactitol and 1,5-anhydro-d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H2O content in bio-oil was decreased dramatically (8.93 wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis. PMID:25136282

Pyrolysis and co-pyrolysis of Laminaria japonica and polypropylene over mesoporous Al-SBA-15 catalyst.

PubMed

Lee, Hyung Won; Choi, Suek Joo; Park, Sung Hoon; Jeon, Jong-Ki; Jung, Sang-Chul; Kim, Sang Chai; Park, Young-Kwon

2014-01-01

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N2 adsorption-desorption isotherms, and NH3 temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H2O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32 wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro-d-galactitol and 1,5-anhydro-d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H2O content in bio-oil was decreased dramatically (8.93 wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis.

Pyrolysis and co-pyrolysis of Laminaria japonica and polypropylene over mesoporous Al-SBA-15 catalyst

NASA Astrophysics Data System (ADS)

Lee, Hyung Won; Choi, Suek Joo; Park, Sung Hoon; Jeon, Jong-Ki; Jung, Sang-Chul; Kim, Sang Chai; Park, Young-Kwon

2014-08-01

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N2 adsorption-desorption isotherms, and NH3 temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H2O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32 wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro- d-galactitol and 1,5-anhydro- d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H2O content in bio-oil was decreased dramatically (8.93 wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis.

Spray Drying of Spinach Juice: Characterization, Chemical Composition, and Storage.

PubMed

Çalışkan Koç, Gülşah; Nur Dirim, Safiye

2017-12-01

The 1st aim of this study is to determine the influence of inlet and outlet air temperatures on the physical and chemical properties of obtained powders from spinach juice (SJ) with 3.2 ± 0.2 °Brix (°Bx). Second, the effect of 3 different drying agents (maltodextrin, whey powder, and gum Arabic) on the same properties was investigated for the selected inlet/outlet temperatures (160/100 °C) which gives the minimum moisture content and water activity values. For this purpose, the total soluble solid content of SJ was adjusted to 5.0 ± 0.2 °Bx with different drying agents. Finally, the effects of different storage conditions (4, 20, and 30 °C) on the physical and chemical properties of spinach powders (SPs) produced at selected conditions were examined. A pilot scale spray dryer was used at 3 different inlet/outlet air temperatures (160 to 200 °C/80 to 100 °C) where the outlet air temperature was controlled by regulating the feed flow rate. Results showed that the moisture content, water activity, browning index, total chlorophyll, and total phenolic contents of the SP significantly decreased and pH and total color change of the SP significantly increased by the addition of different drying agents (P < 0.05). In addition, the changes in the above-mentioned properties were determined during the storage period, at 3 different temperatures. It was also observed that the vitamin C, β-carotene, chlorophyll, and phenolic compounds retention showed first-order degradation kinetic with activation energy of 32.6840, 10.2736, 27.7031, and 28.2634 kJ/K.mol, respectively. © 2017 Institute of Food Technologists®.

Speciation evolution of zinc and copper during pyrolysis and hydrothermal carbonization treatments of sewage sludges

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

Huang, Rixiang; Zhang, Bei; Saad, Emily M.

Thermal and hydrothermal treatments are promising techniques for sewage sludge management that can potentially facilitate safe waste disposal, energy recovery, and nutrient recovery/recycling. Content and speciation of heavy metals in the treatment products affect the potential environmental risks upon sludge disposal and/or application of the treatment products. Therefore, it is important to study the speciation transformation of heavy metals and the effects of treatment conditions. By combining synchrotron X-ray spectroscopy/microscopy analysis and sequential chemical extraction, this study systematically characterized the speciation of Zn and Cu in municipal sewage sludges and their chars derived from pyrolysis (a representative thermal treatment technique)more » and hydrothermal carbonization (HTC; a representative hydrothermal treatment technique). Spectroscopy analysis revealed enhanced sulfidation of Zn and Cu by anaerobic digestion and HTC treatments, as compared to desulfidation by pyrolysis. Overall, changes in the chemical speciation and matrix properties led to reduced mobility of Zn and Cu in the treatment products. These results provide insights into the reaction mechanisms during pyrolysis and HTC treatments of sludges and can help evaluate the environmental/health risks associated with the metals in the treatment products.« less

Polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) mitigation in the pyrolysis process of waste tires using CO₂ as a reaction medium.

PubMed

Kwon, Eilhann E; Oh, Jeong-Ik; Kim, Ki-Hyun

2015-09-01

Our work reported the CO2-assisted mitigation of PAHs and VOCs in the thermo-chemical process (i.e., pyrolysis). To investigate the pyrolysis of used tires to recover energy and chemical products, the experiments were conducted using a laboratory-scale batch-type reactor. In particular, to examine the influence of the CO2 in pyrolysis of a tire, the pyrolytic products including C1-5-hydrocarbons (HCs), volatile organic carbons (VOCs), and polycyclic aromatic hydrocarbons (PAHs) were evaluated qualitatively by gas chromatography (GC) with mass spectroscopy (MS) as well as with a thermal conductivity detector (TCD). The mass balance of the pyrolytic products under various pyrolytic conditions was established on the basis of their weight fractions of the pyrolytic products. Our experimental work experimentally validated that the amount of gaseous pyrolytic products increased when using CO2 as a pyrolysis medium, while substantially altering the production of pyrolytic oil in absolute content (7.3-17.2%) and in relative composition (including PAHs and VOCs). Thus, the co-feeding of CO2 in the pyrolysis process can be considered an environmentally benign and energy efficient process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biomass pyrolysis liquid to citric acid via 2-step bioconversion.

PubMed

Yang, Zhiguang; Bai, Zhihui; Sun, Hongyan; Yu, Zhisheng; Li, Xingxing; Guo, Yifei; Zhang, Hongxun

2014-12-31

The use of fossil carbon sources for fuels and petrochemicals has serious impacts on our environment and is unable to meet the demand in the future. A promising and sustainable alternative is to substitute fossil carbon sources with microbial cell factories converting lignocellulosic biomass into desirable value added products. However, such bioprocesses require tolerance to inhibitory compounds generated during pretreatment of biomass. In this study, the process of sequential two-step bio-conversion of biomass pyrolysis liquid containing levoglucosan (LG) to citric acid without chemical detoxification has been explored, which can greatly improve the utilization efficiency of lignocellulosic biomass. The sequential two-step bio-conversion of corn stover pyrolysis liquid to citric acid has been established. The first step conversion by Phanerochaete chrysosporium (P. chrysosporium) is desirable to decrease the content of other compounds except levoglucosan as a pretreatment for the second conversion. The remaining levoglucosan in solution was further converted into citric acid by Aspergillus niger (A. niger) CBX-209. Thus the conversion of cellulose to citric acid is completed by both pyrolysis and bio-conversion technology. Under experimental conditions, levoglucosan yield is 12% based on the feedstock and the citric acid yield can reach 82.1% based on the levoglucosan content in the pyrolysis liquid (namely 82.1 g of citric acid per 100 g of levoglucosan). The study shows that P. chrysosporium and A. niger have the potential to be used as production platforms for value-added products from pyrolyzed lignocellulosic biomass. Selected P. chrysosporium is able to decrease the content of other compounds except levoglucosan and levoglucosan can be further converted into citric acid in the residual liquids by A. niger. Thus the conversion of cellulose to citric acid is completed by both pyrolysis and bio-conversion technology.

Characterization and Analysis of Paper Spray Ionization of Organic Compounds.

PubMed

Aliaga-Aguilar, Hugo

2018-01-01

Paper spray ionization has arisen relatively recently as a complement and alternative to electro- and nanospray ionization with silica capillaries. A majority of the work in the present literature focuses on the chemical aspect of paper spray. In order to study the physical and phenomenological facet of its implementation, we measured current and voltage distributions of Taylor cones. To study transport phenomena on filter paper, we addressed the behavior of large, sparingly soluble tetraalkylammonium ions, which are usually used as mobility standards, in paper spray. The variation of intensity with time of monomers and dimers of these ions was measured with a differential mobility analyzer and compared with that produced by contamination in the paper. At the same time, we evaluated the proficiency of different paper spray techniques for protein analysis using nano spray as a reference. Experiments suggest that Taylor cones in paper spray are subject to hysteresis, whereas transport phenomena in the porous substrate notably affects the ionization of the sample. Additionally, we observed that paper spray tends to favor lower charge states in proteins. Graphical Abstract.

Conventional and fast pyrolysis of automobile shredder residues (ASR).

PubMed

Zolezzi, Marcello; Nicolella, Cristiano; Ferrara, Sebastiano; Iacobucci, Cesare; Rovatti, Mauro

2004-01-01

This work aims at comparing performance and product yields in conventional pyrolysis and fast pyrolysis of automotive shredded residues. In both processes, carbon conversion to gaseous and liquid products was more than 80%. Gas production was maximised in conventional pyrolysis (about 35% by weight of the initial ASR weight), while fast pyrolysis led to an oil yield higher than 55%. Higher heating values (HHV) of both conventional pyrolysis gas and fast pyrolysis oil increased from 8.8 to 25.07 MJ/Nm3 and from 28.8 and 36.27 MJ/kg with increasing pyrolysis temperature. Copyright 2004 Elsevier Ltd.

Superhydrophobic Ceramic Coatings by Solution Precursor Plasma Spray

PubMed Central

Cai, Yuxuan; Coyle, Thomas W.; Azimi, Gisele; Mostaghimi, Javad

2016-01-01

This work presents a novel coating technique to manufacture ceramic superhydrophobic coatings rapidly and economically. A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS). The effects of various spraying conditions including standoff distance, torch power, number of torch passes, types of solvent and plasma velocity were investigated. The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature. The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces. PMID:27091306

Pyrolysis process for producing fuel gas

NASA Technical Reports Server (NTRS)

Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

2007-01-01

Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

Pyrolysis of corn stalk biomass briquettes in a scaled-up microwave technology.

PubMed

Salema, Arshad Adam; Afzal, Muhammad T; Bennamoun, Lyes

2017-06-01

Pyrolysis of corn stalk biomass briquettes was carried out in a developed microwave (MW) reactor supplied with 2.45GHz frequency using 3kW power generator. MW power and biomass loading were the key parameters investigated in this study. Highest bio-oil, biochar, and gas yield of 19.6%, 41.1%, and 54.0% was achieved at different process condition. In terms of quality, biochar exhibited good heating value (32MJ/kg) than bio-oil (2.47MJ/kg). Bio-oil was also characterised chemically using FTIR and GC-MS method. This work may open new dimension towards development of large-scale MW pyrolysis technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Co-pyrolysis of sewage sludge and manure.

PubMed

Ruiz-Gómez, Nadia; Quispe, Violeta; Ábrego, Javier; Atienza-Martínez, María; Murillo, María Benita; Gea, Gloria

2017-01-01

The management and valorization of residual organic matter, such as sewage sludge and manure, is gaining interest because of the increasing volume of these residues, their localized generation and the related problems. The anaerobic digestion of mixtures of sewage sludge and manure could be performed due to the similarities between both residues. The purpose of this study is to evaluate the feasibility of the co-pyrolysis of sewage sludge (SS) and digested manure (DM) as a potential management technology for these residues. Pyrolysis of a sewage sludge/manure blend (50:50%) was performed at 525°C in a stirred batch reactor under N 2 atmosphere. The product yields and some characteristics of the product were analyzed and compared to the results obtained in the pyrolysis of pure residues. Potential synergetic and antagonist effects during the co-pyrolysis process were evaluated. Although sewage sludge and manure seem similar in nature, there are differences in their pyrolysis product properties and distribution due to their distinct ash and organic matter composition. For the co-pyrolysis of SS and DM, the product yields did not show noticeable synergistic effects with the exception of the yields of organic compounds, being slightly higher than the predicted average, and the H 2 yield, being lower than expected. Co-pyrolysis of SS and DM could be a feasible management alternative for these residues in locations where both residues are generated, since the benefits and the drawbacks of the co-pyrolysis are similar to those of the pyrolysis of each residue. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spray pyrolysed Ru:TiO2 thin film electrodes prepared for electrochemical supercapacitor

NASA Astrophysics Data System (ADS)

Fugare, B. Y.; Thakur, A. V.; Kore, R. M.; Lokhande, B. J.

2018-04-01

Ru doped TiO2 thin films are prepared by using 0.06 M aqueous solution of potassium titanium oxalate (pto), and 0.005 M aqueous solution of ruthenium tri chloride (RuCl3) precursors. The deposition was carried on stainless steel (SS) by using well known ultrasonic spray pyrolysis technique (USPT) at 723° K by maintaining the spray rate 12 cc/min and compressed air flow rate 10 Lmin-1. Prepared Ru:TiO2 thin films were characterized by structurally, morphologically and electrochemically. Deposited RuO2 shows amorphous structure and TiO2 shows tetragonal crystal structure with rutile as prominent phase at very low decomposition temperature. SEM micrographs of RuO2 exhibits porous, interconnected, spherical grains type morphology and TiO2 shows porous, nanorods and nanoplates like morphology and also Ru doped TiO2 shows porous, spherical, granular and nanorods type morphology. The electrochemical cyclic voltammetery shows mixed capacitive behavior. The achieved highest value of specific capacitance 2692 F/g was Ru doped TiO2 electrode in 0.5 M H2SO4.

Plasma Spraying of Ceramics with Particular Difficulties in Processing

NASA Astrophysics Data System (ADS)

Mauer, G.; Schlegel, N.; Guignard, A.; Jarligo, M. O.; Rezanka, S.; Hospach, A.; Vaßen, R.

2015-01-01

Emerging new applications and growing demands of plasma-sprayed coatings initiate the development of new materials. Regarding ceramics, often complex compositions are employed to achieve advanced material properties, e.g., high thermal stability, low thermal conductivity, high electronic and ionic conductivity as well as specific thermo-mechanical properties and microstructures. Such materials however, often involve particular difficulties in processing by plasma spraying. The inhomogeneous dissociation and evaporation behavior of individual constituents can lead to changes of the chemical composition and the formation of secondary phases in the deposited coatings. Hence, undesired effects on the coating characteristics are encountered. In this work, examples of such challenging materials are investigated, namely pyrochlores applied for thermal barrier coatings as well as perovskites for gas separation membranes. In particular, new plasma spray processes like suspension plasma spraying and plasma spray-physical vapor deposition are considered. In some cases, plasma diagnostics are applied to analyze the processing conditions.

Production of bio-oil and biochar from soapstock via microwave-assisted co-catalytic fast pyrolysis.

PubMed

Dai, Leilei; Fan, Liangliang; Liu, Yuhuan; Ruan, Roger; Wang, Yunpu; Zhou, Yue; Zhao, Yunfeng; Yu, Zhenting

2017-02-01

In this study, production of bio-oil and biochar from soapstock via microwave-assisted co-catalytic fast pyrolysis combining the advantages of in-situ and ex-situ catalysis was performed. The effects of catalyst and pyrolysis temperature on product fractional yields and bio-oil chemical compositions were investigated. From the perspective of bio-oil yield, the optimal pyrolysis temperature was 550°C. The use of catalysts reduced the water content, and the addition of bentonite increased the bio-oil yield. Up to 84.16wt.% selectivity of hydrocarbons in the bio-oil was obtained in the co-catalytic process. In addition, the co-catalytic process can reduce the proportion of oxygenates in the bio-oil to 15.84wt.% and eliminate the N-containing compounds completely. The addition of bentonite enhanced the BET surface area of bio-char. In addition, the bio-char removal efficiency of Cd 2+ from soapstock pyrolysis in presence of bentonite was 27.4wt.% higher than without bentonite. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bio-oil from fast pyrolysis of lignin: Effects of process and upgrading parameters.

PubMed

Fan, Liangliang; Zhang, Yaning; Liu, Shiyu; Zhou, Nan; Chen, Paul; Cheng, Yanling; Addy, Min; Lu, Qian; Omar, Muhammad Mubashar; Liu, Yuhuan; Wang, Yunpu; Dai, Leilei; Anderson, Erik; Peng, Peng; Lei, Hanwu; Ruan, Roger

2017-10-01

Effects of process parameters on the yield and chemical profile of bio-oil from fast pyrolysis of lignin and the processes for lignin-derived bio-oil upgrading were reviewed. Various process parameters including pyrolysis temperature, reactor types, lignin characteristics, residence time, and feeding rate were discussed and the optimal parameter conditions for improved bio-oil yield and quality were concluded. In terms of lignin-derived bio-oil upgrading, three routes including pretreatment of lignin, catalytic upgrading, and co-pyrolysis of hydrogen-rich materials have been investigated. Zeolite cracking and hydrodeoxygenation (HDO) treatment are two main methods for catalytic upgrading of lignin-derived bio-oil. Factors affecting zeolite activity and the main zeolite catalytic mechanisms for lignin conversion were analyzed. Noble metal-based catalysts and metal sulfide catalysts are normally used as the HDO catalysts and the conversion mechanisms associated with a series of reactions have been proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling metal droplet sprays in spray forming

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

Muoio, N.G.; Crowe, C.T.; Fritsching, U.

1995-12-31

Spray casting is a process whereby a molten metal stream is atomized and deposited on a substrate. The rapid solidification of the metal droplets gives rise to a fine grain structure and improved material properties. This paper presents a simulation for the fluid and thermal interaction of the fluid and droplets in the spray and the effect on the droplet spray pattern. Good agreement is obtained between the measured and predicted droplet mass flux distribution in the spray.

Cumulative effects of bamboo sawdust addition on pyrolysis of sewage sludge: Biochar properties and environmental risk from metals.

PubMed

Jin, Junwei; Wang, Minyan; Cao, Yucheng; Wu, Shengchun; Liang, Peng; Li, Yanan; Zhang, Jianyun; Zhang, Jin; Wong, Ming Hung; Shan, Shengdao; Christie, Peter

2017-03-01

A novel type of biochar was produced by mixing bamboo sawdust with sewage sludge (1:1, w/w) via a co-pyrolysis process at 400-600°C. Changes in physico-chemical properties and the intrinsic speciation of metals were investigated before and after pyrolysis. Co-pyrolysis resulted in a lower biochar yield but a higher C content in the end product compared with use of sludge alone as the raw material. FT-IR analysis indicates that phosphine derivatives containing PH bonds were formed in the co-pyrolyzed biochars. In addition, co-pyrolysis of sludge with bamboo sawdust transformed the potentially toxic metals in the sludge into more stable fractions, leading to a considerable decrease in their direct toxicity and bioavailability in the co-pyrolyzed biochar. In conclusion, the co-pyrolysis technology provides a feasible method for the safe disposal of metal-contaminated sewage sludge in an attempt to minimize the environmental risk from potentially toxic metals after land application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stable bio-oil production from proteinaceous cyanobacteria: tail gas reactive pyrolysis of spirulina

USDA-ARS?s Scientific Manuscript database

Pyrolysis of Spirulina, a cyanobacteria with high levels of protein (74 wt %) and low levels of lipid (0.8 wt %) content, has the potential to produce fuels and platform chemicals that differ from those produced from lignocellulosic materials. The yields and product distribution from fluidized-bed p...

Structural, optical and photoelectric properties of sprayed CdS thin films

NASA Astrophysics Data System (ADS)

Chandel, Tarun; Dwivedi, Shailendra Kumar; Zaman, M. Burhanuz; Rajaram, P.

2018-05-01

In this study, CdS thin films were grown via a facile spray pyrolysis technique. The crystalline phase, morphological, compositional and optical properties of the CdS thin films have been studied using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis absorption spectroscopy, respectively. XRD patterns show that the grown CdS films crystallized in the hexagonal structure. Scanning electron microscopy (SEM) study shows that the surfaces of the films are smooth and are uniformly covered with nanoparticles. EDAX results reveal that the grown films have good stochiometry. UV-vis spectroscopy shows that the grown films have transparency above 80% over the entire visible region. The photo-electric response of the CdS films grown on glass substrates has been observed.

Chemical Synthesis Accelerated by Paper Spray: The Haloform Reaction

ERIC Educational Resources Information Center

Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

2016-01-01

In this laboratory, students perform a synthetic reaction in two ways: (i) by traditional bulk-phase reaction and (ii) in the course of reactive paper spray ionization. Mass spectrometry (MS) is used both as an analytical method and a means of accelerating organic syntheses. The main focus of this laboratory exercise is that the same ionization…

Method and apparatus for heat extraction by controlled spray cooling

DOEpatents

Edwards, Christopher Francis; Meeks, Ellen; Kee, Robert; McCarty, Kevin

1999-01-01

Two solutions to the problem of cooling a high temperature, high heat flux surface using controlled spray cooling are presented for use on a mandrel. In the first embodiment, spray cooling is used to provide a varying isothermal boundary layer on the side portions of a mandrel by providing that the spray can be moved axially along the mandrel. In the second embodiment, a spray of coolant is directed to the lower temperature surface of the mandrel. By taking advantage of super-Leidenfrost cooling, the temperature of the high temperature surface of the mandrel can be controlled by varying the mass flux rate of coolant droplets. The invention has particular applicability to the field of diamond synthesis using chemical vapor deposition techniques.

Phosphorus recovery and reuse by pyrolysis: Applications for agriculture and environment.

PubMed

Sun, Daquan; Hale, Lauren; Kar, Gourango; Soolanayakanahally, Raju; Adl, Sina

2018-03-01

Phosphorus ore extraction for soil fertilization supports the demand of modern agriculture, but extractable resource limitations, due to scarcity, impose a P reuse and recycling research agenda. Here we propose to integrate biochar production (pyrogenic carbon) with municipal and agricultural waste management systems, to recover and reuse phosphorous that would otherwise be lost from the ecological food web. A meta-analysis and available data on total P in biochar indicated that P-enriched feedstocks include animal manure, human excreta, and plant-biomass collected from P-polluted sites. Phosphorus in biochar could participate in P equilibriums in soils and is expected to supply P. The release, sorption and desorption of P by biochar will codetermine the potential of P replenishment by biochar and P loss from biochar-amended soils. Abiotic and biotic factors are expected to affect sorption/desorption of P between biochar and soil aggregates, and P acquisition by plants. Chemical extraction, using acid or alkaline solutions, is considered as a means for P retrieval from high P biochar, especially for biochar with high heavy metal contents. To bridge the gap between academia and practice, this paper proposes future development for phosphorus acclamation by pyrolysis: 1) identification of high-P bio-waste for pyrolysis; 2) retrieval of P by using biochar as soil amendment or by chemical leaching; 3) biochar modification by inorganic nutrients, P solubilizing microorganisms and other organic matter; and 4) compatible pyrolysis equipment fit to the current waste management context, such as households, and waste water treatment plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recycling of organic materials and solder from waste printed circuit boards by vacuum pyrolysis-centrifugation coupling technology.

PubMed

Zhou, Yihui; Wu, WenBiao; Qiu, Keqiang

2011-12-01

Here, we focused on the recycling of waste printed circuit boards (WPCBs) using vacuum pyrolysis-centrifugation coupling technology (VPCT) aiming to obtain valuable feedstock and resolve environmental pollution. The two types of WPCBs were pyrolysed at 600°C for 30 min under vacuum condition. During the pyrolysis process, the solder of WPCBs was separated and recovered when the temperature range was 400-600°C, and the rotating drum was rotated at 1000 rpm for 10 min. The type-A of WPCBs pyrolysed to form an average of 67.91 wt.% residue, 27.84 wt.% oil, and 4.25 wt.% gas; and pyrolysis of the type-B of WPCBs led to an average mass balance of 72.22 wt.% residue, 21.57 wt.% oil, and 6.21 wt.% gas. The GC-MS and FT-IR analyses showed that the two pyrolysis oils consisted mainly of phenols and substituted phenols. The pyrolysis oil can be used for fuel or chemical feedstock for further processing. The recovered solder can be recycled directly and it can also be a good resource of lead and tin for refining. The pyrolysis residues contained various metals, glass fibers and other inorganic materials, which could be recovered after further treatment. The pyrolysis gases consisted mainly of CO, CO(2), CH(4), and H(2), which could be collected and recycled. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of pressure on morphology and structure of bio-char from pressurized entrained-flow pyrolysis of microalgae.

PubMed

Maliutina, Kristina; Tahmasebi, Arash; Yu, Jianglong

2018-06-01

The present dataset describes the entrained-flow pyrolysis of Microalgae Chlorella vulgaris and the results obtained during bio-char characterization. The dataset includes a brief explanation of the experimental procedure, experimental conditions and the influence of pyrolysis conditions on bio-chars morphology and carbon structure. The data show an increase in sphericity and surface smoothness of bio-chars at higher pressures and temperatures. Data confirmed that the swelling ratio of bio-chars increased with pressure up to 2.0 MPa. Consequently, changes in carbon structure of bio-chars were investigated using Raman spectroscopy. The data showed the increase in carbon order of chars at elevated pressures. Changes in the chemical structure of bio-char as a function of pyrolysis conditions were investigated using FTIR analysis.

Chemical compatibility and properties of suspension plasma-sprayed SrTiO3-based anodes for intermediate-temperature solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Zhang, Shan-Lin; Li, Cheng-Xin; Li, Chang-Jiu

2014-10-01

La-doped strontium titanate (LST) is a promising, redox-stable perovskite material for direct hydrocarbon oxidation anodes in intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this study, nano-sized LST and Sm-doped ceria (SDC) powders are produced by the sol-gel and glycine-nitrate processes, respectively. The chemical compatibility between LST and electrolyte materials is studied. A LST-SDC composite anode is prepared by suspension plasma spraying (SPS). The effects of annealing conditions on the phase structure, microstructure, and chemical stability of the LST-SDC composite anode are investigated. The results indicate that the suspension plasma-sprayed LST-SDC anode has the same phase structure as the original powders. LST exhibits a good chemical compatibility with SDC and Mg/Sr-doped lanthanum gallate (LSGM). The anode has a porosity of ∼40% with a finely porous structure that provides high gas permeability and a long three-phase boundary for the anode reaction. Single cells assembled with the LST-SDC anode, La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte, and La0.8Sr0.2CoO3-SDC cathode show a good performance at 650-800 °C. The annealing reduces the impedances due to the enhancement in the bonding between the particles in the anode and interface of anode and LSGM electrolyte, thus improving the output performance of the cell.

An experimental and kinetic modeling study on dimethyl carbonate (DMC) pyrolysis and combustion

DOE PAGES

Sun, Wenyu; Yang, Bin; Hansen, Nils; ...

2015-12-08

Because of the absence of C–C bonds and the large oxygen content in its molecular structure, dimethyl carbonate (DMC) is a promising oxygenated additive or substitute for hydrocarbon fuels. In order to understand its chemical oxidation and combustion kinetics, flow reactor pyrolysis at different pressures (40, 200 and 1040 mbar) and low-pressure laminar premixed flames with different equivalence ratios (1.0 and 1.5) were investigated. Mole fraction profiles of many reaction intermediates and products were obtained within estimated experimental uncertainties. From theoretical calculations and estimations, a detailed kinetic model for DMC pyrolysis and high-temperature combustion consisting of 257 species and 1563more » reactions was developed. The performance of the kinetic model was then analyzed using detailed chemical composition information, primarily from the present measurements. In addition, it was examined against the chemical structure of an opposed-flow diffusion flame, relying on global combustion properties such as the ignition delay times and laminar burning velocities. Furthermore, these extended comparisons yielded overall satisfactory agreement, demonstrating the applicability of the present model over a wide range of high-temperature conditions.« less

Systematization of material consumption norms in spray-coating

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

Lelyukh, I.M.

1995-03-01

Regulating the consumption of materials is particularly important in the economics and organization of spray-coating operations. Three main factors are taken into account when establishing norms for the consumption of the materials of the coating: the physicomechanical and chemical properties of the particles; the shape of the substrate; the dimensions of the substrate. The most important parameters of the spraying regime are the velocity and temperature of the particles. Given the same velocity, the optimum particle kinetic energy for producing a strong bond with the substrate depends on particle shape and size and the density of the materials being spray-coated.more » These parameters determine the heating of the particles in the plasma jet or, in the case of the use of a detonation gun, during collision with the surface of the part. Powders of fragmented or drop shape are used to obtain coatings by spraying.« less

A review on thermal and catalytic pyrolysis of plastic solid waste (PSW).

PubMed

Al-Salem, S M; Antelava, A; Constantinou, A; Manos, G; Dutta, A

2017-07-15

Plastic plays an important role in our daily lives due to its versatility, light weight and low production cost. Plastics became essential in many sectors such as construction, medical, engineering applications, automotive, aerospace, etc. In addition, economic growth and development also increased our demand and dependency on plastics which leads to its accumulation in landfills imposing risk on human health, animals and cause environmental pollution problems such as ground water contamination, sanitary related issues, etc. Hence, a sustainable and an efficient plastic waste treatment is essential to avoid such issues. Pyrolysis is a thermo-chemical plastic waste treatment technique which can solve such pollution problems, as well as, recover valuable energy and products such as oil and gas. Pyrolysis of plastic solid waste (PSW) has gained importance due to having better advantages towards environmental pollution and reduction of carbon footprint of plastic products by minimizing the emissions of carbon monoxide and carbon dioxide compared to combustion and gasification. This paper presents the existing techniques of pyrolysis, the parameters which affect the products yield and selectivity and identify major research gaps in this technology. The influence of different catalysts on the process as well as review and comparative assessment of pyrolysis with other thermal and catalytic plastic treatment methods, is also presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

Valorisation of waste tyre by pyrolysis in a moving bed reactor.

PubMed

Aylón, E; Fernández-Colino, A; Murillo, R; Navarro, M V; García, T; Mastral, A M

2010-07-01

The aim of this work is to assess the behaviour of a moving bed reactor, based on a screw transporter design, in waste tyre pyrolysis under several experimental conditions. Waste tyre represents a significant problem in developed countries and it is necessary to develop new technology that could easily process big amounts of this potentially raw material. In this work, the influence of the main pyrolysis process variables (temperature, solid residence time, mass flow rate and inert gas flow) has been studied by a thorough analysis of product yields and properties. It has been found that regardless the process operational parameters, a total waste tyre devolatilisation is achieved, producing a pyrolytic carbon black with a volatile matter content under 5 wt.%. In addition, it has been proven that, in the range studied, the most influencing process variables are temperature and solid mass flow rate, mainly because both variables modify the gas residence time inside the reactor. In addition, it has been found that the modification of these variables affects to the chemical properties of the products. This fact is mainly associated to the different cracking reaction of the primary pyrolysis products. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Valorisation of waste tyre by pyrolysis in a moving bed reactor

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

Aylon, E.; Fernandez-Colino, A.; Murillo, R., E-mail: ramonm@icb.csic.e

2010-07-15

The aim of this work is to assess the behaviour of a moving bed reactor, based on a screw transporter design, in waste tyre pyrolysis under several experimental conditions. Waste tyre represents a significant problem in developed countries and it is necessary to develop new technology that could easily process big amounts of this potentially raw material. In this work, the influence of the main pyrolysis process variables (temperature, solid residence time, mass flow rate and inert gas flow) has been studied by a thorough analysis of product yields and properties. It has been found that regardless the process operationalmore » parameters, a total waste tyre devolatilisation is achieved, producing a pyrolytic carbon black with a volatile matter content under 5 wt.%. In addition, it has been proven that, in the range studied, the most influencing process variables are temperature and solid mass flow rate, mainly because both variables modify the gas residence time inside the reactor. In addition, it has been found that the modification of these variables affects to the chemical properties of the products. This fact is mainly associated to the different cracking reaction of the primary pyrolysis products.« less

Spray CVD for Making Solar-Cell Absorber Layers

NASA Technical Reports Server (NTRS)

Banger, Kulbinder K.; Harris, Jerry; Jin, Michael H.; Hepp, Aloysius

2007-01-01

Spray chemical vapor deposition (spray CVD) processes of a special type have been investigated for use in making CuInS2 absorber layers of thin-film solar photovoltaic cells from either of two subclasses of precursor compounds: [(PBu3) 2Cu(SEt)2In(SEt)2] or [(PPh3)2Cu(SEt)2 In(SEt)2]. The CuInS2 films produced in the experiments have been characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and four-point-probe electrical tests.

Methane Synthesis from Automotive Paint Sludge via Microwave Assisted Pyrolysis

NASA Astrophysics Data System (ADS)

Rosli, N. L.; Rahman, N. Abd; Kadri, A.

2018-05-01

Methane gas, which has one atom of carbon and four atoms of hydrogen, is a valuable energy resource, which can be used in the energy sector. The purpose of this research work is to identify methane synthesis from Automotive Paint Sludge (APS) using microwave assisted pyrolysis. APS is known as a hazardous waste since it contains various chemicals that categorized as heavy metals and toxic substances. A modified conventional kitchen microwave was used to pyrolise the APS. The microwave was set with the power level of 600 W and 50 minutes radiation time. Through the experiment, pyrogas was collected into tedlar bag and was analysed using Gas Chromatography with Flame Ionization Detector (GC-FID). Results from the GC-FID were shown that the retention time of 3.3583, 3.2733, and 3.2267 min are proved to be methane gas. The results obtained are resembled with the results from the literature. This indicates methane gas was presented in the pyrogas of pyrolysis of APS and there is a possibility of producing methane gas. The research study suggests that it is possible to synthesize methane gas from the APS via microwave assisted pyrolysis, and in the meantime reduce the volume of APS in the landfill.

Sprayed nanostructured TiO2 films for efficient photocatalytic degradation of textile azo dye.

PubMed

Stambolova, Irina; Shipochka, Capital Em Cyrillicaria; Blaskov, Vladimir; Loukanov, Alexandrе; Vassilev, Sasho

2012-12-05

Spray pyrolysis procedure for preparation of nanostructured TiO(2) films with higher photocatalytic effectiveness and longer exploitation life is presented in this study. Thin films of active nanocrystalline TiO(2) were obtained from titanium isopropoxide, stabilized with acetyl acetone and characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The activity of sprayed nanostructured TiO(2) is tested for photocatalytic degradation of Reactive Black 5 dye with concentrations up to 80 ppm. Interesting result of the work is the reduction of toxicity after photocatalytic treatment of RB5 with TiO(2), which was confirmed by the lower percentage of mortality of Artemia salina. It was proved that the film thickness, conditions of post deposition treatment and the type of the substrate affected significantly the photocatalytic reaction. Taking into account that the parameters are interdependent, it is necessary to optimize the preparation conditions in order to synthesize photocatalytic active films. Copyright © 2012 Elsevier B.V. All rights reserved.

Pyrolysis reaction models of waste tires: Application of Master-Plots method for energy conversion via devolatilization.

PubMed

Irmak Aslan, Dilan; Parthasarathy, Prakash; Goldfarb, Jillian L; Ceylan, Selim

2017-10-01

Land applied disposal of waste tires has far-reaching environmental, economic, and human health consequences. Pyrolysis represents a potential waste management solution, whereby the solid carbonaceous residue is heated in the absence of oxygen to produce liquid and gaseous fuels, and a solid char. The design of an efficient conversion unit requires information on the reaction kinetics of pyrolysis. This work is the first to probe the appropriate reaction model of waste tire pyrolysis. The average activation energy of pyrolysis was determined via iso-conversional methods over a mass fraction conversion range between 0.20 and 0.80 to be 162.8±23.2kJmol -1 . Using the Master Plots method, a reaction order of three was found to be the most suitable model to describe the pyrolytic decomposition. This suggests that the chemical reactions themselves (cracking, depolymerization, etc.), not diffusion or boundary layer interactions common with carbonaceous biomasses, are the rate-limiting steps in the pyrolytic decomposition of waste tires. Copyright © 2017 Elsevier Ltd. All rights reserved.

Upgrading of bio-oil from the pyrolysis of biomass over the rice husk ash catalysts

NASA Astrophysics Data System (ADS)

Sutrisno, B.; Hidayat, A.

2016-11-01

The pyrolysis oils are complex mixtures of organic compounds that exhibit a wide spectrum of chemical functionality, and generally contain some water. Their direct use as fuels may present some difficulties due to their high viscosity, poor heating value, corrosiveness and instability. For possible future use as replacements for hydrocarbon chemical feedstocks and fuels, the liquids will require considerable upgrading to improve its characteristics. By esterification of the bio oil as the upgrading method, the properties of the bio-oil could be improved. In the paper, the upgrading of a bio-oil obtained by pyrolysis was studied over rice husk ash catalysts. The raw bio-oil was produced by pyrolysis of rice husk.From the experiment results, it can be concluded that the densities of upgraded bio-oil were reduced from 1.24 to 0.95 g.cm-3, and the higherheating value increased from 16.0 to 27.2 MJ/kg and the acidity of upgraded bio-oil was also alleviated from 2.3 to 4.4. The results of gas chromatography-mass spectrometry (GC-MS) and FT-IR analysis showed that the ester compounds in the upgraded bio-oil increased. It is possible to improve the properties of bio-oil by esterifying the raw bio-oil.

Noncircular Cross Sections Could Enhance Mixing in Sprays

NASA Technical Reports Server (NTRS)

Bellan, Josette; Abdel-Hameed, Hesham

2003-01-01

A computational study has shown that by injecting drops in jets of gas having square, elliptical, triangular, or other noncircular injection cross sections, it should be possible to increase (relative to comparable situations having circular cross section) the entrainment and dispersion of liquid drops. This finding has practical significance for a variety of applications in which it is desirable to increase dispersion of drops. For example, in chemical-process sprays, increased dispersion leads to increases in chemical- reaction rates; in diesel engines, increasing the dispersion of drops of sprayed fuel reduces the production of soot; and in household and paint sprays, increasing the dispersion of drops makes it possible to cover larger surfaces. It has been known for some years that single-phase fluid jets that enter flow fields through noncircular inlets entrain more fluid than do comparable jets entering through circular inlets. The computational study reported here was directed in part toward determining whether and how this superior mixing characteristic of noncircular single phase jets translates to a similar benefit in cases of two-phase jets (that is, sprays). The study involved direct numerical simulations of single- and two-phase free jets with circular, elliptical, rectangular, square, and triangular inlet cross sections. The two-phase jets consisted of gas laden with liquid drops randomly injected at the inlets. To address the more interesting case of evaporating drops, the carrier gas in the jets was specified to be initially unvitiated by the vapor of the liquid chemical species and the initial temperature of the drops was chosen to be smaller than that of the gas. The mathematical model used in the study was constructed from the conservation equations for the two-phase flow and included complete couplings of mass, momentum, and energy based on thermodynamically self-consistent specification of the enthalpy, internal energy, and latent heat of

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.

Mass spectrometric studies of fast pyrolysis of cellulose

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

Degenstein, John; Hurt, Matt; Murria, Priya

2015-01-01

A fast pyrolysis probe/linear quadrupole ion trap mass spectrometer combination was used to study the primary fast pyrolysis products (those that first leave the hot pyrolysis surface) of cellulose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, as well as of cellobiosan, cellotriosan, and cellopentosan, at 600°C. Similar products with different branching ratios were found for the oligosaccharides and cellulose, as reported previously. However, identical products (with the exception of two) with similar branching ratios were measured for cellotriosan (and cellopentosan) and cellulose. This result demonstrates that cellotriosan is an excellent small-molecule surrogate for studies of the fast pyrolysis of cellulose andmore » also that most fast pyrolysis products of cellulose do not originate from the reducing end. Based on several observations, the fast pyrolysis of cellulose is suggested to initiate predominantly via two competing processes: the formation of anhydro-oligosaccharides, such as cellobiosan, cellotriosan, and cellopentosan (major route), and the elimination of glycolaldehyde (or isomeric) units from the reducing end of oligosaccharides formed from cellulose during fast pyrolysis.« less

Effects of growth temperatures on the physical properties of Cu2ZnSnS4 thin films deposited through spray pyrolysis for solar cell applications

NASA Astrophysics Data System (ADS)

Fadavieslam, M. R.; Keshavarz, S.

2018-02-01

This paper reports the effects of substrate temperature on the structural, optical, and electrical properties of Cu2ZnSnS4 (CZTS) thin films deposited on soda lime glass through spray pyrolysis without sulfurization. Substrate temperatures ranged from 250 to 500 °C at a step of 50 °C, and a precursor solution was prepared by dissolving copper chloride, zinc acetate, zinc chloride, and thiourea in ethanol and di-ionized water. The films were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy, ultraviolet-visible spectroscopy, and electrical resistance and Hall effect measurements, respectively, obtained by two-point probe and van der Pauw techniques. XRD revealed the formation of polycrystalline CZTS thin films and the appearance of relatively intense and sharp diffraction peaks at (112), (200), (220), and (312) of a kesterite phase with (112) preferential orientation, in which the crystalline degree increased as substrate temperature increased. Surface morphological analysis demonstrated the formation of a smooth, compact, and uniform CZTS surface. When substrate temperature increased from 250 to 500 °C, single-crystal grains increased from 6.38 to 28 nm, carrier concentration increased from 3.4 × 1017 to 2.36 × 1019 cm-3, Hall mobility increased from 30.96 to 68.52 cm2/V.S, optical band gap decreased from 1.74 to 1.14 eV, and resistivity decreased from 0.59 to 3.87 × 10-3 Ωcm. Hall effect analysis indicated that the films exhibited p-type conductivity.

Spray distribution evaluation of different settings of a hand-held-trolley sprayer used in greenhouse tomato crops.

PubMed

Llop, Jordi; Gil, Emilio; Gallart, Montserrat; Contador, Felipe; Ercilla, Mireia

2016-03-01

Hand-held-trolley sprayers have recently been promoted to improve spray application techniques in greenhouses in south-eastern Spain. However, certain aspects remain to be improved. A modified hand-held-trolley sprayer was evaluated under two different canopy conditions (high and low canopy density) and with several sprayer settings (nozzle type, air assistance and spray volume). In this study, the deposition, coverage and uniformity of distribution of the spray on the canopy have been assessed. The deposition on leaves was significantly higher when flat-fan nozzles and air assistance were used at both high and low spray volumes. No differences were detected between the reference system at a high spray volume and the modified trolley at a low spray volume. Flat-fan nozzles with air assistance increased penetrability into the canopy. Air assistance and flat-fan nozzles allow volume rates to be reduced while maintaining or improving spray quality distribution. The working parameters of hand-held sprayers must be considered to reduce environmental risk and increase the efficacy of the spraying process. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Production of zinc and manganese oxide particles by pyrolysis of alkaline and Zn-C battery waste.

PubMed

Ebin, Burçak; Petranikova, Martina; Steenari, Britt-Marie; Ekberg, Christian

2016-05-01

Production of zinc and manganese oxide particles from alkaline and zinc-carbon battery black mass was studied by a pyrolysis process at 850-950°C with various residence times under 1L/minN2(g) flow rate conditions without using any additive. The particular and chemical properties of the battery waste were characterized to investigate the possible reactions and effects on the properties of the reaction products. The thermodynamics of the pyrolysis process were studied using the HSC Chemistry 5.11 software. The carbothermic reduction reaction of battery black mass takes place and makes it possible to produce fine zinc particles by a rapid condensation, after the evaporation of zinc from a pyrolysis batch. The amount of zinc that can be separated from the black mass is increased by both pyrolysis temperature and residence time. Zinc recovery of 97% was achieved at 950°C and 1h residence time using the proposed alkaline battery recycling process. The pyrolysis residue is mainly MnO powder with a low amount of zinc, iron and potassium impurities and has an average particle size of 2.9μm. The obtained zinc particles have an average particle size of about 860nm and consist of hexagonal crystals around 110nm in size. The morphology of the zinc particles changes from a hexagonal shape to s spherical morphology by elevating the pyrolysis temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Compound-specific stable carbon isotopic signature of carbohydrate pyrolysis products from C3 and C4 plants.

PubMed

González-Pérez, José A; Jiménez-Morillo, Nicasio T; de la Rosa, José M; Almendros, Gonzalo; González-Vila, Francisco J

2016-02-01

Pyrolysis-compound specific isotopic analysis (Py-CSIA: Py-GC-(FID)-C-IRMS) is a relatively novel technique that allows on-line quantification of stable isotope proportions in chromatographically separated products released by pyrolysis. Validation of the Py-CSIA technique is compulsory for molecular traceability in basic and applied research. In this work, commercial sucrose from C4 (sugarcane) and C3 (sugarbeet) photosystem plants and admixtures were studied using analytical pyrolysis (Py-GC/MS), bulk δ(13)C IRMS and δ(13)C Py-CSIA. Major pyrolysis compounds were furfural (F), furfural-5-hydroxymethyl (HMF) and levoglucosan (LV). Bulk and main pyrolysis compound δ(13)C (‰) values were dependent on plant origin: C3 (F, -24.65 ± 0.89; HMF, -22.07 ± 0.41‰; LV, -21.74 ± 0.17‰) and C4 (F, -14.35 ± 0.89‰; HMF, -11.22 ± 0.54‰; LV, -11.44 ± 1.26‰). Significant regressions were obtained for δ(13)C of bulk and pyrolysis compounds in C3 and C4 admixtures. Furfural (F) was found (13)C depleted with respect to bulk and HMF and LV, indicating the incorporation of the light carbon atom in position 6 of carbohydrates in the furan ring after pyrolysis. This is the first detailed report on the δ(13)C signature of major pyrolytically generated carbohydrate-derived molecules. The information provided by Py-CSIA is valuable for identifying source marker compounds of use in food science/fraud detection or in environmental research. © 2015 Society of Chemical Industry.

Ex-situ catalytic pyrolysis of wastewater sewage sludge - A micro-pyrolysis study.

PubMed

Wang, Kaige; Zheng, Yan; Zhu, Xifeng; Brewer, Catherine E; Brown, Robert C

2017-05-01

Concerns over increasing amounts of sewage sludge and unsustainability of current disposal methods have led to development of alternative routes for sludge management. The large amount of organics in sewage sludge makes it potential feedstock for energy or fuel production via thermochemical pathways. In this study, ex-situ catalytic pyrolysis using HZSM-5 catalyst was explored for the production of olefinic and aromatic hydrocarbons and nutrient-rich char from sewage sludge. The optimal pyrolysis and catalysis temperatures were found to be 500°C and 600°C, respectively. Carbon yields of hydrocarbons from sewage sludge were higher than for lignocellulose; yield differences were attributed to the high extractives content in the sludge. Full recovery of most inorganic elements were found in the char, which suggests that catalyst deactivation maybe alleviated through ex-situ catalytic pyrolysis. Most of the nitrogen was retained in the char while 31.80% was released as ammonia, which suggests a potential for nitrogen recycling. Copyright © 2017 Elsevier Ltd. All rights reserved.

Processes for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil, and apparatuses for treating biomass-derived pyrolysis oil

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

Baird, Lance Awender; Brandvold, Timothy A.

Processes and apparatuses for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil are provided herein. An exemplary process for washing a spent ion exchange bed employed in purification of biomass-derived pyrolysis oil includes the step of providing a ion-depleted pyrolysis oil stream having an original oxygen content. The ion-depleted pyrolysis oil stream is partially hydrotreated to reduce the oxygen content thereof, thereby producing a partially hydrotreated pyrolysis oil stream having a residual oxygen content that is less than the original oxygen content. At least a portion of the partially hydrotreated pyrolysis oil stream is passed throughmore » the spent ion exchange bed. Water is passed through the spent ion exchange bed after passing at least the portion of the partially hydrotreated pyrolysis oil stream therethrough.« less

Pyrolysis processing for solid waste resource recovery

NASA Technical Reports Server (NTRS)

Wojtowicz, Marek A. (Inventor); Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Suuberg, Eric M. (Inventor)

2007-01-01

Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

The Influence of Zeolites on Radical Formation During Lignin Pyrolysis.

PubMed

Bährle, Christian; Custodis, Victoria; Jeschke, Gunnar; van Bokhoven, Jeroen A; Vogel, Frédéric

2016-09-08

Lignin from lignocellulosic biomass is a promising source of energy, fuels, and chemicals. The conversion of the polymeric lignin to fuels and chemicals can be achieved by catalytic and noncatalytic pyrolysis. The influence of nonporous silica and zeolite catalysts, such as silicalite, HZSM5, and HUSY, on the radical and volatile product formation during lignin pyrolysis was studied by in situ high-temperature electron paramagnetic resonance spectroscopy (HTEPR) as well as GC-MS. Higher radical concentrations were observed in the samples containing zeolite compared to the sample containing only lignin, which suggests that there is a stabilizing effect by the inorganic surfaces on the formed radical fragments. This effect was observed for nonporous silica as well as for HUSY, HZSM5, and silicalite zeolite catalysts. However, the effect is far larger for the zeolites owing to their higher specific surface area. The zeolites also showed an effect on the volatile product yield and the product distribution within the volatile phase. Although silicalite showed no effect on the product selectivity, the acidic zeolites such as HZSM5 or HUSY increased the formation of deoxygenated products such as benzene, toluene, xylene (BTX), and naphthalene. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An overview of spray drift reduction testing of spray nozzles

USDA-ARS?s Scientific Manuscript database

The importance of the development and testing of drift reduction technologies (DRTs) is increasing. Common spray drift reduction technologies include spray nozzles and spray adjuvants. Following draft procedures developed for a DRT program, three spray nozzles were tested under high air speed cond...

Influence of Cold-Sprayed, Warm-Sprayed, and Plasma-Sprayed Layers Deposition on Fatigue Properties of Steel Specimens

NASA Astrophysics Data System (ADS)

Cizek, J.; Matejkova, M.; Dlouhy, I.; Siska, F.; Kay, C. M.; Karthikeyan, J.; Kuroda, S.; Kovarik, O.; Siegl, J.; Loke, K.; Khor, Khiam Aik

2015-06-01

Titanium powder was deposited onto steel specimens using four thermal spray technologies: plasma spray, low-pressure cold spray, portable cold spray, and warm spray. The specimens were then subjected to strain-controlled cyclic bending test in a dedicated in-house built device. The crack propagation was monitored by observing the changes in the resonance frequency of the samples. For each series, the number of cycles corresponding to a pre-defined specimen cross-section damage was used as a performance indicator. It was found that the grit-blasting procedure did not alter the fatigue properties of the steel specimens (1% increase as compared to as-received set), while the deposition of coatings via all four thermal spray technologies significantly increased the measured fatigue lives. The three high-velocity technologies led to an increase of relative lives to 234% (low-pressure cold spray), 210% (portable cold spray), and 355% (warm spray) and the deposition using plasma spray led to an increase of relative lives to 303%. The observed increase of high-velocity technologies (cold and warm spray) could be attributed to a combination of homogeneous fatigue-resistant coatings and induction of peening stresses into the substrates via the impingement of the high-kinetic energy particles. Given the intrinsic character of the plasma jet (low-velocity impact of semi/molten particles) and the mostly ceramic character of the coating (oxides, nitrides), a hypothesis based on non-linear coatings behavior is provided in the paper.

Catalytic fast pyrolysis of lignocellulosic biomass

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

Liu, Changjun; Wang, Huamin; Karim, Ayman M.

2014-11-21

Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy Q3 carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectivelymore » convert lignocellulose into a liquid fuel—bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating values, high corrosiveness, high viscosity, and instability; they also greatly Q4 limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality.« less

Methods for deoxygenating biomass-derived pyrolysis oil

DOEpatents

Brandvold, Timothy A.

2015-07-14

Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method comprising the steps of diluting the biomass-derived pyrolysis oil with a phenolic-containing diluent to form a diluted pyoil-phenolic feed is provided. The diluted pyoil-phenolic feed is contacted with a deoxygenating catalyst in the presence of hydrogen at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

Coal liquefaction with subsequent bottoms pyrolysis

DOEpatents

Walchuk, George P.

1978-01-01

In a coal liquefaction process wherein heavy bottoms produced in a liquefaction zone are upgraded by coking or a similar pyrolysis step, pyrolysis liquids boiling in excess of about 1000.degree. F. are further reacted with molecular hydrogen in a reaction zone external of the liquefaction zone, the resulting effluent is fractionated to produce one or more distillate fractions and a bottoms fraction, a portion of this bottoms fraction is recycled to the reaction zone, and the remaining portion of the bottoms fraction is recycled to the pyrolysis step.

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.

Effect of pyrolysis temperature on characteristics and aromatic contaminants adsorption behavior of magnetic biochar derived from pyrolysis oil distillation residue.

PubMed

Li, Hao; Mahyoub, Samah Awadh Ali; Liao, Wenjie; Xia, Shuqian; Zhao, Hechuan; Guo, Mengya; Ma, Peisheng

2017-01-01

The magnetic biochars were easily fabricated by thermal pyrolysis of Fe(NO 3 ) 3 and distillation residue derived from rice straw pyrolysis oil at 400, 600 and 800°C. The effects of pyrolysis temperature on characteristics of magnetic biochars as well as adsorption capacity for aromatic contaminants (i.e., anisole, phenol and guaiacol) were investigated carefully. The degree of carbonization of magnetic biochars become higher as pyrolysis temperature increasing. The magnetic biochar reached the largest surface area and pore volume at the pyrolysis temperature of 600°C due to pores blocking in biochar during pyrolysis at 800°C. Based on batch adsorption experiments, the used adsorbent could be magnetically separated and the adsorption capacity of anisole on magnetic biochars was stronger than that of phenol and guaiacol. The properties of magnetic biochar, including surface area, pore volume, aromaticity, grapheme-like-structure and iron oxide (γ-Fe 2 O 3 ) particles, showed pronounced effects on the adsorption performance of aromatic contaminants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analytical methods to characterize heterogeneous raw material for thermal spray process: cored wire Inconel 625

NASA Astrophysics Data System (ADS)

Lindner, T.; Bonebeau, S.; Drehmann, R.; Grund, T.; Pawlowski, L.; Lampke, T.

2016-03-01

In wire arc spraying, the raw material needs to exhibit sufficient formability and ductility in order to be processed. By using an electrically conductive, metallic sheath, it is also possible to handle non-conductive and/or brittle materials such as ceramics. In comparison to massive wire, a cored wire has a heterogeneous material distribution. Due to this fact and the complex thermodynamic processes during wire arc spraying, it is very difficult to predict the resulting chemical composition in the coating with sufficient accuracy. An Inconel 625 cored wire was used to investigate this issue. In a comparative study, the analytical results of the raw material were compared to arc sprayed coatings and droplets, which were remelted in an arc furnace under argon atmosphere. Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) analysis were used to determine the chemical composition. The phase determination was performed by X-ray diffraction (XRD). The results were related to the manufacturer specifications and evaluated in respect to differences in the chemical composition. The comparison between the feedstock powder, the remelted droplets and the thermally sprayed coatings allows to evaluate the influence of the processing methods on the resulting chemical and phase composition.

Kinetic and energy production analysis of pyrolysis of lignocellulosic biomass using a three-parallel Gaussian reaction model.

PubMed

Chen, Tianju; Zhang, Jinzhi; Wu, Jinhu

2016-07-01

The kinetic and energy productions of pyrolysis of a lignocellulosic biomass were investigated using a three-parallel Gaussian distribution method in this work. The pyrolysis experiment of the pine sawdust was performed using a thermogravimetric-mass spectroscopy (TG-MS) analyzer. A three-parallel Gaussian distributed activation energy model (DAEM)-reaction model was used to describe thermal decomposition behaviors of the three components, hemicellulose, cellulose and lignin. The first, second and third pseudocomponents represent the fractions of hemicellulose, cellulose and lignin, respectively. It was found that the model is capable of predicting the pyrolysis behavior of the pine sawdust. The activation energy distribution peaks for the three pseudo-components were centered at 186.8, 197.5 and 203.9kJmol(-1) for the pine sawdust, respectively. The evolution profiles of H2, CH4, CO, and CO2 were well predicted using the three-parallel Gaussian distribution model. In addition, the chemical composition of bio-oil was also obtained by pyrolysis-gas chromatography/mass spectrometry instrument (Py-GC/MS). Copyright © 2016 Elsevier Ltd. All rights reserved.

Ex-situ catalytic co-pyrolysis of lignin and polypropylene to upgrade bio-oil quality by microwave heating.

PubMed

Duan, Dengle; Wang, Yunpu; Dai, Leilei; Ruan, Roger; Zhao, Yunfeng; Fan, Liangliang; Tayier, Maimaitiaili; Liu, Yuhuan

2017-10-01

Microwave-assisted fast co-pyrolysis of lignin and polypropylene for bio-oil production was conducted using the ex-situ catalysis technology. Effects of catalytic temperature, feedstock/catalyst ratio, and lignin/polypropylene ratio on product distribution and chemical components of bio-oil were investigated. The catalytic temperature of 250°C was the most conducive to bio-oil production in terms of the yield. The bio-oil yield decreased with the addition of catalyst during ex-situ catalytic co-pyrolysis. When the feedstock/catalyst ratio was 2:1, the minimum char and coke values were 21.22% and 1.54%, respectively. The proportion of cycloalkanes decreased and the aromatics increased with the increasing catalyst loading. A positive synergistic effect was observed between lignin and polypropylene. The char yield dramatically deceased and the bio-oil yield improved during co-pyrolysis compared with those during lignin pyrolysis alone. The proportion of oxygenates dramatically and the minimum value of 6.74% was obtained when the lignin/polypropylene ratio was 1:1. Copyright © 2017. Published by Elsevier Ltd.

Reprint of: Pyrolysis technologies for municipal solid waste: A review

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

Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn; Yin, Lijie; Wang, Huan

2015-03-15

Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis inmore » regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.« less

Pyrolysis Strategies for Effective Utilization of Lignocellulosic and Algal Biomass

NASA Astrophysics Data System (ADS)

Maddi, Balakrishna

Pyrolysis is a processing technique involving thermal degradation of biomass in the absence of oxygen. The bio-oils obtained following the condensation of the pyrolysis vapors form a convenient starting point for valorizing the major components of lignocellulosic as well as algal biomass feed stocks for the production of fuels and value-added chemicals. Pyrolysis can be implemented on whole biomass or on residues left behind following standard fractionation methods. Microalgae and oil seeds predominantly consist of protein, carbohydrate and triglycerides, whereas lignocellulose is composed of carbohydrates (cellulose and hemicellulose) and lignin. The differences in the major components of these two types of biomass will necessitate different pyrolysis strategies to derive the optimal benefits from the resulting bio-oils. In this thesis, novel pyrolysis strategies were developed that enable efficient utilization of the bio-oils (and/or their vapors) from lignocellulose, algae, as well as oil seed feed stocks. With lignocellulosic feed stocks, pyrolysis of whole biomass as well as the lignin residue left behind following well-established pretreatment and saccharification (i.e., depolymerization of cellulose and hemicellulose to their monomeric-sugars) of the biomass was studied with and without catalysts. Following this, pyrolysis of (lipid-deficient) algae and lignocellulosic feed stocks, under similar reactor conditions, was performed for comparison of product (bio-oil, gas and bio-char) yields and composition. In spite of major differences in component bio-polymers, feedstock properties relevant to thermo-chemical conversions, such as overall C, H and O-content, C/O and H/C molar ratio as well as calorific values, were found to be similar for algae and lignocellulosic material. Bio-oil yields from algae and some lignocellulosic materials were similar; however, algal bio-oils were compositionally different and contained several N-compounds (most likely from

Linking pyrolysis and anaerobic digestion (Py-AD) for the conversion of lignocellulosic biomass.

PubMed

Fabbri, Daniele; Torri, Cristian

2016-04-01

Biogas is a mixture of CO2 and CH4 produced by a consortia of Bacteria and Archeae operating in anaerobic digestion (AD) plants. Biogas can be burnt as such in engines to produce electricity and heat or upgraded into biomethane. Biomethane is a drop-in fuel that can be injected in the natural gas grid or utilised as a transport fuel. While a wide array of biomass feedstock can be degraded into biogas, unconverted lignin, hemicellulose and cellulose end up in the co-product digestate leaving a large portion of chemical energy unutilised. Pyrolysis (Py) transforms in a single step and without chemical reagents the lignocellulose matrix into gaseous (syngas), liquid (bio-oil, pyrolysis oil) and solid (biochar) fractions for the development of renewable fuels and materials. The Py route applied downstream to AD is actively investigated in order to valorise the solid digestate presently destined only for soil applications. Coupling Py upstream to AD is an emerging field of research aimed at expanding the feedstock towards biologically recalcitrant substrates (wood, paper, sludge). The biomethanation potential was demonstrated for gaseous (H2/CO) and water soluble pyrolysis products, while the influence of insoluble pyrolytic lignin remains fairly unexplored. Biochar can promote the production of biomethane by acting as a support for microorganism colonisation, conductor for direct interspecies electron transfer, sorbent for hydrophobic inhibitors, and reactant for in situ biogas upgrading. Enhancing the advantages (carbon source) over the side effects (toxicity) of Py fractions represents the main challenge of Py-AD. This can be addressed by increasing the selectivity of the thermochemical process or improving the ecological flexibility of mixed bacterial consortia towards chemically complex environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stability of extemporaneously prepared preservative-free prochlorperazine nasal spray.

PubMed

Yellepeddi, Venkata K

2018-01-01

The stability of an extemporaneously prepared preservative-free prochlorperazine 5-mg/mL nasal spray was evaluated. The preservative-free prochlorperazine nasal spray was prepared by adding 250 mg of prochlorperazine edisylate to 50 mL of citrate buffer in a low-density polyethylene nasal spray bottle. A stability-indicating high-performance liquid chromatography (HPLC) method was developed and validated using the major degradant prochlorperazine sulfoxide and by performing forced-degradation studies. For chemical stability studies, 3 100-μL samples of the preservative-free prochlorperazine from 5 nasal spray bottles stored at room temperature were collected at days 0, 20, 30, 45, and 60 and were assayed in triplicate using the stability-indicating HPLC method. Microbiological testing involved antimicrobial effectiveness testing based on United States Pharmacopeia ( USP ) chapter 51 and quantitative microbiological enumeration of aerobic bacteria, yeasts, and mold based on USP chapter 61. Samples for microbiological testing were collected at days 0, 30, and 60. The stability-indicating HPLC method clearly identified the degradation product prochlorperazine sulfoxide without interference from prochlorperazine. All tested solutions retained over 90% of the initial prochlorperazine concentration for the 60-day study period. There were no detectable changes in color, pH, and viscosity in any sample. There was no growth of bacteria, yeast, and mold for 60 days in all samples tested. An extemporaneously prepared preservative-free nasal spray solution of prochlorperazine edisylate 5 mg/mL was physically, chemically, and microbiologically stable for 60 days when stored at room temperature in low-density polyethylene bottles. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Kinetics of coffee industrial residue pyrolysis using distributed activation energy model and components separation of bio-oil by sequencing temperature-raising pyrolysis.

PubMed

Chen, Nanwei; Ren, Jie; Ye, Ziwei; Xu, Qizhi; Liu, Jingyong; Sun, Shuiyu

2016-12-01

This study was carried out to investigate the kinetics of coffee industrial residue (CIR) pyrolysis, the effect of pyrolysis factors on yield of bio-oil component and components separation of bio-oil. The kinetics of CIR pyrolysis was analyzed using distributed activation energy model (DAEM), based on the experiments in thermogravimetric analyzer (TGA), and it indicated that the average of activation energy (E) is 187.86kJ·mol -1 . The bio-oils were prepared from CIR pyrolysis in vacuum tube furnace, and its components were determined by gas chromatography/mass spectrometry (GC-MS). Among pyrolysis factors, pyrolysis temperature is the most influential factor on components yield of bio-oil, directly concerned with the volatilization and yield of components (palmitic acid, linoleic acid, oleic acid, octadecanoic acid and caffeine). Furthermore, a new method (sequencing temperature-raising pyrolysis) was put forward and applied to the components separation of bio-oil. Based on experiments, a solution of components separation of bio-oil was come out. Copyright © 2016 Elsevier Ltd. All rights reserved.

Plasma Pyrolysis Assembly Regeneration Evaluation

NASA Technical Reports Server (NTRS)

Medlen, Amber; Abney, Morgan B.; Miller, Lee A.

2011-01-01

In April 2010 the Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS). This technology requires hydrogen to recover oxygen from carbon dioxide. This results in the production of water and methane. Water is electrolyzed to provide oxygen to the crew. Methane is vented to space resulting in a loss of valuable hydrogen and unreduced carbon dioxide. This is not critical for ISS because of the water resupply from Earth. However, in order to have enough oxygen for long-term missions, it will be necessary to recover the hydrogen to maximize oxygen recovery. Thus, the Plasma Pyrolysis Assembly (PPA) was designed to recover hydrogen from methane. During operation, the PPA produces small amounts of carbon that can ultimately reduce performance by forming on the walls and windows of the reactor chamber. The carbon must be removed, although mechanical methods are highly inefficient, thus chemical methods are of greater interest. The purpose of this effort was to determine the feasibility of chemically removing the carbon from the walls and windows of a PPA reactor using a pure carbon dioxide stream.

Recycling slaughterhouse waste into fertilizer: how do pyrolysis temperature and biomass additions affect phosphorus availability and chemistry?

PubMed

Zwetsloot, Marie J; Lehmann, Johannes; Solomon, Dawit

2015-01-01

Pyrolysis of slaughterhouse waste could promote more sustainable phosphorus (P) usage through the development of alternative P fertilizers. This study investigated how pyrolysis temperature (220, 350, 550 and 750 °C), rendering before pyrolysis, and wood or corn biomass additions affect P chemistry in bone char, plant availability, and its potential as P fertilizer. Linear combination fitting of synchrotron-based X-ray absorption near edge structure spectra demonstrated that higher pyrolysis temperatures decreased the fit with organic P references, but increased the fit with a hydroxyapatite (HA) reference, used as an indicator of high calcium phosphate (CaP) crystallinity. The fit to the HA reference increased from 0% to 69% in bone with meat residue and from 20% to 95% in rendered bone. Biomass additions to the bone with meat residue reduced the fit to the HA reference by 83% for wood and 95% for corn, and additions to rendered bone by 37% for wood. No detectable aromatic P forms were generated by pyrolysis. High CaP crystallinity was correlated with low water-extractable P, but high formic acid-extractable P indicative of high plant availability. Bone char supplied available P which was only 24% lower than Triple Superphosphate fertilizer and two- to five-fold higher than rock phosphate. Pyrolysis temperature and biomass additions can be used to design P fertilizer characteristics of bone char through changing CaP crystallinity that optimize P availability to plants. © 2014 Society of Chemical Industry.

Chapter 8: Pyrolysis of Biomass for Aviation Fuel

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

Robichaud, David J; Jenkins, Rhodri W.; Sutton, Andrew D.

2016-07-15

Pyrolysis, the breaking down of organic material using heat and the absence of oxygen, is a method that has been widely researched for the production of liquid fuels. In this chapter, we review the feedstocks typically used for pyrolysis, the properties and the composition of the liquid fraction (termed 'bio-oil') obtained, the studies in which pyrolysis has been used in an attempt to increase the bio-oil yield, and how the bio-oil has been upgraded to fuel-like molecules. We also discuss the viability of pyrolysis to produce jet fuel hydrocarbons.

An Optically Accessible Pyrolysis Microreactor

NASA Astrophysics Data System (ADS)

Baraban, Joshua H.; David, Donald E.; Ellison, Barney; Daily, John W.

2016-06-01

We report an optically accessible pyrolysis micro-reactor suitable for in situ laser spectroscopic measurements. A radiative heating design allows for completely unobstructed views of the micro-reactor along two axes. The maximum temperature demonstrated here is only 1300 K (as opposed to 1700 K for the usual SiC micro-reactor) because of the melting point of fused silica, but alternative transparent materials will allow for higher temperatures. Laser induced fluorescence measurements on nitric oxide are presented as a proof of principle for spectroscopic characterization of pyrolysis conditions. (This work has been published in J. H. Baraban, D. E. David, G. B. Ellison, and J. W. Daily. An Optically Accessible Pyrolysis Micro-Reactor. Review of Scientific Instruments, 87(1):014101, 2016.)

Desulfurized gas production from vertical kiln pyrolysis

DOEpatents

Harris, Harry A.; Jones, Jr., John B.

1978-05-30

A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

PubMed

Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

2013-02-01

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low

Principle considerations for the risk assessment of sprayed consumer products.

PubMed

Steiling, W; Bascompta, M; Carthew, P; Catalano, G; Corea, N; D'Haese, A; Jackson, P; Kromidas, L; Meurice, P; Rothe, H; Singal, M

2014-05-16

In recent years, the official regulation of chemicals and chemical products has been intensified. Explicitly for spray products enhanced requirements to assess the consumers'/professionals' exposure to such product type have been introduced. In this regard the Aerosol-Dispensers-Directive (75/324/EEC) with obligation for marketing aerosol dispensers, and the Cosmetic-Products-Regulation (1223/2009/EC) which obliges the insurance of a safety assessment, have to be mentioned. Both enactments, similar to the REACH regulation (1907/2006/EC), require a robust chemical safety assessment. From such assessment, appropriate risk management measures may be identified to adequately control the risk of these chemicals/products to human health and the environment when used. Currently, the above-mentioned regulations lack the guidance on which data are needed for preparing a proper hazard analysis and safety assessment of spray products. Mandatory in the process of inhalation risk and safety assessment is the determination and quantification of the actual exposure to the spray product and more specifically, its ingredients. In this respect the current article, prepared by the European Aerosol Federation (FEA, Brussels) task force "Inhalation Toxicology", intends to introduce toxicological principles and the state of the art in currently available exposure models adapted for typical application scenarios. This review on current methodologies is intended to guide safety assessors to better estimate inhalation exposure by using the most relevant data. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Standardization of chemical analytical techniques for pyrolysis bio-oil: history, challenges, and current status of methods

DOE PAGES

Ferrell, Jack R.; Olarte, Mariefel V.; Christensen, Earl D.; ...

2016-07-05

Here, we discuss the standardization of analytical techniques for pyrolysis bio-oils, including the current status of methods, and our opinions on future directions. First, the history of past standardization efforts is summarized, and both successful and unsuccessful validation of analytical techniques highlighted. The majority of analytical standardization studies to-date has tested only physical characterization techniques. In this paper, we present results from an international round robin on the validation of chemical characterization techniques for bio-oils. Techniques tested included acid number, carbonyl titrations using two different methods (one at room temperature and one at 80 °C), 31P NMR for determination ofmore » hydroxyl groups, and a quantitative gas chromatography–mass spectrometry (GC-MS) method. Both carbonyl titration and acid number methods have yielded acceptable inter-laboratory variabilities. 31P NMR produced acceptable results for aliphatic and phenolic hydroxyl groups, but not for carboxylic hydroxyl groups. As shown in previous round robins, GC-MS results were more variable. Reliable chemical characterization of bio-oils will enable upgrading research and allow for detailed comparisons of bio-oils produced at different facilities. Reliable analytics are also needed to enable an emerging bioenergy industry, as processing facilities often have different analytical needs and capabilities than research facilities. We feel that correlations in reliable characterizations of bio-oils will help strike a balance between research and industry, and will ultimately help to -determine metrics for bio-oil quality. Lastly, the standardization of additional analytical methods is needed, particularly for upgraded bio-oils.« less

Standardization of chemical analytical techniques for pyrolysis bio-oil: history, challenges, and current status of methods

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

Ferrell, Jack R.; Olarte, Mariefel V.; Christensen, Earl D.

Here, we discuss the standardization of analytical techniques for pyrolysis bio-oils, including the current status of methods, and our opinions on future directions. First, the history of past standardization efforts is summarized, and both successful and unsuccessful validation of analytical techniques highlighted. The majority of analytical standardization studies to-date has tested only physical characterization techniques. In this paper, we present results from an international round robin on the validation of chemical characterization techniques for bio-oils. Techniques tested included acid number, carbonyl titrations using two different methods (one at room temperature and one at 80 °C), 31P NMR for determination ofmore » hydroxyl groups, and a quantitative gas chromatography–mass spectrometry (GC-MS) method. Both carbonyl titration and acid number methods have yielded acceptable inter-laboratory variabilities. 31P NMR produced acceptable results for aliphatic and phenolic hydroxyl groups, but not for carboxylic hydroxyl groups. As shown in previous round robins, GC-MS results were more variable. Reliable chemical characterization of bio-oils will enable upgrading research and allow for detailed comparisons of bio-oils produced at different facilities. Reliable analytics are also needed to enable an emerging bioenergy industry, as processing facilities often have different analytical needs and capabilities than research facilities. We feel that correlations in reliable characterizations of bio-oils will help strike a balance between research and industry, and will ultimately help to -determine metrics for bio-oil quality. Lastly, the standardization of additional analytical methods is needed, particularly for upgraded bio-oils.« less

Comparative study on pyrolysis of lignocellulosic and algal biomass using pyrolysis-gas chromatography/mass spectrometry.

PubMed

Li, Kai; Zhang, Liqiang; Zhu, Liang; Zhu, Xifeng

2017-06-01

The cornstalk and chlorella were selected as the representative of lignocelulosic and algal biomass, and the pyrolysis experiments of them were carried out using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The physicochemical properties of samples and the pyrolytic product distribution were presented. And then the compositional differences between the two kinds of pyrolytic products were studied, the relevant pyrolysis mechanisms were analyzed systematically. Pyrolytic vapor from lignocellulosic biomass contained more phenolic and carbonyl compounds while that from algal biomass contained more long-chain fatty acids, nitrogen-containing compounds and fewer carbonyl compounds. Maillard reaction is conducive to the conversion of carbonyl compounds to nitrogenous heterocyclic compounds with better thermal stability. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Injuries from pepper spray used for self defense: analysis of 15 cases managed in an emergency chemical decontamination area].

PubMed

Amigó, Montserrat; Fernández, Fuensanta; Velasco, Verónica; Nogué, Santiago

2016-10-01

We analyzed epidemiologic and clinical characteristics, treatment received, and clinical course in cases of pepper spray injury treated in the chemical decontamination area of an emergency department over a 5-year period. A total of 15 patients with a mean (SD) age of 25 (8.3) years were included. Thirteen were men and 53% were foreign-born. All uses of pepper spray occurred during muggings that to place mainly in the early hours of the morning (66.7% between 4:30 and 6:30 AM). Two or more attackers were injured in 60% of the events. Seventy-three percent of the attacks took place on the street and the median delay in reaching the emergency department was 30 minutes. The face and eyes were usually injured, and symptoms included itching, irritation, burning, and pain. On arrival, the patients were treated immediately (mean delay, 3 minutes) with hypertonic saline, an amphoteric surfactant, and a chelating agent in 80% of the cases, in which improvement was substantial as mean pain scale scores changed from 7.2 on admission to 3 on discharge (P=.009). Patients spent an average of 40 minutes in the treatment area. Eleven patients required further care from an ophthalmologist and topical medication for symptoms. Outcomes were good and there were no complications in any of the cases. We conclude that pepper sprays are being used as an aid to self defense in muggings in our community. Decontamination measures have priority as they alleviate symptoms and prevent long-lasting effects.