The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform
Leo A Behie - One of the best experts on this subject based on the ideXlab platform.
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CS2 Formation in the Claus Reaction Furnace: A Kinetic Study of Methane−Sulfur and Methane−Hydrogen Sulfide Reactions
Industrial & Engineering Chemistry Research, 2004Co-Authors: And Kunal Karan, Leo A BehieAbstract:Improving the understanding of reaction kinetics of CS2 formation in the Claus Plant front-end reaction furnace (RF) is a key step in developing strategies to reduce CS2 formation and, consequently, the environmental impact of Claus Plants. Specifically, experiments were carried out in a high-temperature flow reactor with pressures of 101−150 kPa, temperatures of 800−1250 °C, and residence times of 90−1400 ms to study the kinetics of CH4−S2 and CH4−H2S reactions; these conditions are typical of those encountered in the Claus RF. The reaction between methane and sulfur was found to be very rapid, resulting in complete consumption of sulfur in less than 100 ms at 1100 °C with formation of CS2 and H2S as the primary sulfur-containing products. At higher temperature (>1000 °C), the produced H2S decomposes with a proportional increase in CS2 formation. A simple rate expression for CS2 formation was obtained, and a kinetic model was developed to describe H2S formation/consumption in the CH4−S2 system. In the CH...
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the fate of methane in a Claus Plant reaction furnace
Canadian Journal of Chemical Engineering, 2001Co-Authors: Hilton S F Chin, Anil K Mehrotra, Kunal Karan, Leo A BehieAbstract:Experimental kinetic data are reported for key side reactions occurring in the front end [i. e. the reaction furnace (RF) and the waste heat boiler (WHB)] of modified Claus Plants used for sulfur recovery from the sour gases evolved in the treatment of natural gas. An extensive experimental study was conducted in a high temperature tubular reactor system for two important homogenous gas-phase reactions. Firstly, experiments were carried out to study the oxidation of hydrogen sulfide and methane mixtures in the presence of oxygen. Secondly, the reaction between methane and sulfur dioxide was investigated experimentally. These results showed that methane was much less competitive for oxygen than hydrogen sulfide. Hence, in a partially oxidizing environment of a RF, data showed that methane reacted significantly with other major sulfur containing species, as secondary reactions, to form COS and especially CS2. This is highly problematic from an environmental point of view. Des donnees cinetiques experimentales sont presentees pour les principales reactions secondaires survenant dans la partie frontale [c.-a-d. le four de reaction (RF) et la chaudiere de recuperation des chaleurs perdues (WHB)] d'usines Claus modifiees pour la recuperation du soufre a partir des gaz acides produits dans le traitement du gaz naturel. Une etude experimental approfondie a ete menee dans un reacteur tubulaire a temperatures elevees pour deux reactions en phase gazeuse homogenes. On a d'abord mene des experiences afin d'etudier l'oxydation des melanges d'hydrogene sulfure et de methane en presence d'oxygene. On a ensuite etudie experimentalement la reaction entre le methane et le dioxyde de soufre. Les resultats montrent que le methane est beaucoup moins competitif pour l'oxygene que pour l'hydrogene sulfure. En consequence, dans un environnement partiellement oxydant d'un RF, les donnees montrent que le methane reagit de maniere importante avec les autres especes principales contenant du soufre, comme reactions secondaires, pour former du COS et particulierement du CS2.Ceciest hautement problematique d'un point de vue environnemental.
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Use of new reaction kinetics for COS formation to achieve reduced sulfur emissions from Claus Plants
Canadian Journal of Chemical Engineering, 1999Co-Authors: Kunal Karan, Anil K Mehrotra, Leo A BehieAbstract:A simulation study of COS formation in the tubes of the waste heat boiler (WHB) located just after the reaction furnace of a Claus Plant is reported. First, the kinetics of the COS forming reaction were obtained from a recently completed experimental program in our laboratory. The predictions for COS formation from the newly developed kinetic model were compared with the data from an actual industrial waste heat boiler and found to be in good agreement. The simulation results showed that up to a 50% reduction in the COS production may be achieved by operating the WHB at the maximum allowable gas mass velocity in the WHB tubes coupled with the use of a smaller diameter tube. These reductions have major implications on the overall sulfur recovery from Claus Plants. On presente une etude de simulation de la formation de COS dans des tubes d'une chaudiere de recuperation des chaleurs perdues (WHB) placee juste apres le four de reaction d'une unite de Claus. Les cinetiques de la reaction de formation de COS ont ete obtenues a partir d'un programme experimental realise recemment dans notre laboratoire. Les predictions de la formation de COS fournies par le modele cinetique nouvellement etabli ont ete comparees a des donnees d'une chaudiere de recuperation des chaleurs perdues industrielle et un bon accord a ete trouve. Les resultats de la simulation montrent qu'il est possible de reduire jusqu'a 50% la production de COS en faisant fonctionner la chaudiere a la plus grande vitesse massique de gaz disponible dans les tubes de la chaudiere tout en utilisant des tubes du plus petit diametre possible Ces reductions ont des repercussions majeures sur la recuperation de soufre globale des unites de Claus.
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hydrodynamic and kinetic modelling of circulating fluidized bed reactors applied to a modified Claus Plant
Chemical Engineering Science, 1996Co-Authors: David M J Puchyr, Anil K Mehrotra, Leo A Behie, Nicolas KalogerakisAbstract:Simulations of circulating fluidized-bed (CFB) reactors applied to the modified Claus process were performed to assess their potential for eliminating the costly tail gas clean-up unit (TGCU) from a Claus Plant. The TGCU could be eliminated by achieving very high H2S conversions in the catalytic reactors. Both the CFB regimes of pneumatic transport and fast fluidization were examined. Moreover, a newly developed CFB model accounting for the downflow of both the gas and solids in the annulus was applied to the fast fluidization regime. Recently published intrinsic reaction kinetics were employed for the hydrolysis of the problematic COS and CS2 compounds on the Kaiser 201 alumina catalyst. The simulation results were compared to the work of Birkholz et al. (1987, Can. J. Chem. Engn# 65, 778-784), who simulated the use of conventional gas fluidized-bed converters in a Claus Plant. The simulated three reactor, adiabatic CFB system operating in the pneumatic transport regime was able to achieve an overall sulfur recovery of 96.2%. Removal of H20 before each reactor improved the recovery to over 99%. Copyright © 1996 Elsevier Science Ltd
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Estimate gas emissivities for equipment and process design
Chemical Engineering Progress, 1995Co-Authors: Anil K Mehrotra, Kunal Karan, Leo A BehieAbstract:The major contribution to heat transfer from flames and gases produced by conventional fuels is thermal radiation from water vapor, carbon dioxide, carbon monoxide, and soot. At the high temperatures typically encountered in furnaces and process equipment, radiative heat transfer is important mostly for heteropolar gases, the most common of which are CO{sub 2}, H{sub 2}O, CO, CH{sub 4}, SO{sub 2}, and NH{sub 3}. On the other hand, gases with symmetrical molecules, such as H{sub 2}, O{sub 2}, and N{sub 2}, do not show absorption bands at the wavelengths encountered in most industrial equipment; hence, these are transparent to radiation and have negligible emissivities. This article presents a simple design equation for estimating the total emissivity of six nontransparent gray gases, namely CO{sub 2}, H{sub 2}O, CO, CH{sub 4}, SO{sub 2}, and NH{sub 3}, based on the data plotted in published emissivity charts. Correlations are also provided for three emissivity correction factors, namely the pressure correction factors for CO{sub 2} and H{sub 2}O and the spectral overlap correction in CO{sub 2}-H{sub 2}O mixtures. Finally, the use of the design equation is illustrated by estimating the emissivity of the gas mixture in the waste heat boiler of a Claus Plant.
Dl Johnson - One of the best experts on this subject based on the ideXlab platform.
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Regenerable Solid Sorbents for Claus Tailgas Cleanup: A Treatment Process for the Catalytic Removal of SO2 and H2S
Industrial and Engineering Chemistry Research, 1996Co-Authors: Js Buchanan, Dl Stern, Ke Nariman, Gj Teitman, Jf Sodomin, Dl JohnsonAbstract:Use of a regenerable solid sorbent can offer advantages over conventional wet scrubbing for Claus tailgas treatment. In this paper, we describe a novel process/catalyst combination for this service. The Mobil Oil SOx Treatment (MOST) process, demonstrated here on the laboratory scale, consists of first combusting the Claus tailgas with air, converting all sulfur species to SO2/SO3. The SOx is then sorbed onto a solid sorbent, and in a separate step, the sulfur is reductively desorbed as a concentrated stream of mainly SO2 and H2S, which can then be recycled to the Claus Plant for further processing. Catalyst screening for this application focused on examining alumina and magnesium aluminates, with oxidation promoters including ceria, vanadia, and platinum. The materials with the highest SOx uptake are a commercial FCC SOx transfer additive and a vanadia/ceria-promoted, magnesium aluminate (V/Ce/Mg2Al2O5) spinel (54 and 46 wt% SOx uptake, respectively). During most of the adsorption period, the SO2 level in the effluent from the sorbent bed was below 1 ppmv. When the same base magnesium aluminate was examined with ceria but without vanadia, the SOx uptake was lower (25 wt%), while the base alone had fairly low uptake (5 wt%). Thus, effective SO2 oxidation promoters are necessary for this application. Oxidation of CO to CO2 was also demonstrated over these catalysts. All materials examined were found to be regenerable under hydrogen. The main products observed were SO2, H2O, and H2S. The results indicate that a regenerable solid sorbent-based SOx abatement system can give lower emissions of sulfur species and of CO than current Claus treatment processes and may allow a capacity increase in a hydraulically limited Claus Plant.
David L Johnson - One of the best experts on this subject based on the ideXlab platform.
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regenerable solid sorbents for Claus tailgas cleanup a treatment process for the catalytic removal of so2 and h2s
Industrial & Engineering Chemistry Research, 1996Co-Authors: John S Buchanan, Ke Nariman, Gj Teitman, Jf Sodomin, David L Stern, David L JohnsonAbstract:Use of a regenerable solid sorbent can offer advantages over conventional wet scrubbing for Claus tailgas treatment. In this paper, we describe a novel process/catalyst combination for this service. The Mobil Oil SOx Treatment (MOST) process, demonstrated here on the laboratory scale, consists of first combusting the Claus tailgas with air, converting all sulfur species to SO2/SO3. The SOx is then sorbed onto a solid sorbent, and in a separate step, the sulfur is reductively desorbed as a concentrated stream of mainly SO2 and H2S, which can then be recycled to the Claus Plant for further processing. Catalyst screening for this application focused on examining alumina and magnesium aluminates, with oxidation promoters including ceria, vanadia, and platinum. The materials with the highest SOx uptake are a commercial FCC SOx transfer additive and a vanadia/ceria-promoted, magnesium aluminate (V/Ce/Mg2Al2O5) spinel (54 and 46 wt % SOx uptake, respectively). During most of the adsorption period, the SO2 level ...
Ke Nariman - One of the best experts on this subject based on the ideXlab platform.
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regenerable solid sorbents for Claus tailgas cleanup a treatment process for the catalytic removal of so2 and h2s
Industrial & Engineering Chemistry Research, 1996Co-Authors: John S Buchanan, Ke Nariman, Gj Teitman, Jf Sodomin, David L Stern, David L JohnsonAbstract:Use of a regenerable solid sorbent can offer advantages over conventional wet scrubbing for Claus tailgas treatment. In this paper, we describe a novel process/catalyst combination for this service. The Mobil Oil SOx Treatment (MOST) process, demonstrated here on the laboratory scale, consists of first combusting the Claus tailgas with air, converting all sulfur species to SO2/SO3. The SOx is then sorbed onto a solid sorbent, and in a separate step, the sulfur is reductively desorbed as a concentrated stream of mainly SO2 and H2S, which can then be recycled to the Claus Plant for further processing. Catalyst screening for this application focused on examining alumina and magnesium aluminates, with oxidation promoters including ceria, vanadia, and platinum. The materials with the highest SOx uptake are a commercial FCC SOx transfer additive and a vanadia/ceria-promoted, magnesium aluminate (V/Ce/Mg2Al2O5) spinel (54 and 46 wt % SOx uptake, respectively). During most of the adsorption period, the SO2 level ...
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Regenerable Solid Sorbents for Claus Tailgas Cleanup: A Treatment Process for the Catalytic Removal of SO2 and H2S
Industrial and Engineering Chemistry Research, 1996Co-Authors: Js Buchanan, Dl Stern, Ke Nariman, Gj Teitman, Jf Sodomin, Dl JohnsonAbstract:Use of a regenerable solid sorbent can offer advantages over conventional wet scrubbing for Claus tailgas treatment. In this paper, we describe a novel process/catalyst combination for this service. The Mobil Oil SOx Treatment (MOST) process, demonstrated here on the laboratory scale, consists of first combusting the Claus tailgas with air, converting all sulfur species to SO2/SO3. The SOx is then sorbed onto a solid sorbent, and in a separate step, the sulfur is reductively desorbed as a concentrated stream of mainly SO2 and H2S, which can then be recycled to the Claus Plant for further processing. Catalyst screening for this application focused on examining alumina and magnesium aluminates, with oxidation promoters including ceria, vanadia, and platinum. The materials with the highest SOx uptake are a commercial FCC SOx transfer additive and a vanadia/ceria-promoted, magnesium aluminate (V/Ce/Mg2Al2O5) spinel (54 and 46 wt% SOx uptake, respectively). During most of the adsorption period, the SO2 level in the effluent from the sorbent bed was below 1 ppmv. When the same base magnesium aluminate was examined with ceria but without vanadia, the SOx uptake was lower (25 wt%), while the base alone had fairly low uptake (5 wt%). Thus, effective SO2 oxidation promoters are necessary for this application. Oxidation of CO to CO2 was also demonstrated over these catalysts. All materials examined were found to be regenerable under hydrogen. The main products observed were SO2, H2O, and H2S. The results indicate that a regenerable solid sorbent-based SOx abatement system can give lower emissions of sulfur species and of CO than current Claus treatment processes and may allow a capacity increase in a hydraulically limited Claus Plant.
Gj Teitman - One of the best experts on this subject based on the ideXlab platform.
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regenerable solid sorbents for Claus tailgas cleanup a treatment process for the catalytic removal of so2 and h2s
Industrial & Engineering Chemistry Research, 1996Co-Authors: John S Buchanan, Ke Nariman, Gj Teitman, Jf Sodomin, David L Stern, David L JohnsonAbstract:Use of a regenerable solid sorbent can offer advantages over conventional wet scrubbing for Claus tailgas treatment. In this paper, we describe a novel process/catalyst combination for this service. The Mobil Oil SOx Treatment (MOST) process, demonstrated here on the laboratory scale, consists of first combusting the Claus tailgas with air, converting all sulfur species to SO2/SO3. The SOx is then sorbed onto a solid sorbent, and in a separate step, the sulfur is reductively desorbed as a concentrated stream of mainly SO2 and H2S, which can then be recycled to the Claus Plant for further processing. Catalyst screening for this application focused on examining alumina and magnesium aluminates, with oxidation promoters including ceria, vanadia, and platinum. The materials with the highest SOx uptake are a commercial FCC SOx transfer additive and a vanadia/ceria-promoted, magnesium aluminate (V/Ce/Mg2Al2O5) spinel (54 and 46 wt % SOx uptake, respectively). During most of the adsorption period, the SO2 level ...
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Regenerable Solid Sorbents for Claus Tailgas Cleanup: A Treatment Process for the Catalytic Removal of SO2 and H2S
Industrial and Engineering Chemistry Research, 1996Co-Authors: Js Buchanan, Dl Stern, Ke Nariman, Gj Teitman, Jf Sodomin, Dl JohnsonAbstract:Use of a regenerable solid sorbent can offer advantages over conventional wet scrubbing for Claus tailgas treatment. In this paper, we describe a novel process/catalyst combination for this service. The Mobil Oil SOx Treatment (MOST) process, demonstrated here on the laboratory scale, consists of first combusting the Claus tailgas with air, converting all sulfur species to SO2/SO3. The SOx is then sorbed onto a solid sorbent, and in a separate step, the sulfur is reductively desorbed as a concentrated stream of mainly SO2 and H2S, which can then be recycled to the Claus Plant for further processing. Catalyst screening for this application focused on examining alumina and magnesium aluminates, with oxidation promoters including ceria, vanadia, and platinum. The materials with the highest SOx uptake are a commercial FCC SOx transfer additive and a vanadia/ceria-promoted, magnesium aluminate (V/Ce/Mg2Al2O5) spinel (54 and 46 wt% SOx uptake, respectively). During most of the adsorption period, the SO2 level in the effluent from the sorbent bed was below 1 ppmv. When the same base magnesium aluminate was examined with ceria but without vanadia, the SOx uptake was lower (25 wt%), while the base alone had fairly low uptake (5 wt%). Thus, effective SO2 oxidation promoters are necessary for this application. Oxidation of CO to CO2 was also demonstrated over these catalysts. All materials examined were found to be regenerable under hydrogen. The main products observed were SO2, H2O, and H2S. The results indicate that a regenerable solid sorbent-based SOx abatement system can give lower emissions of sulfur species and of CO than current Claus treatment processes and may allow a capacity increase in a hydraulically limited Claus Plant.