@article { ISI:000240615500001, title = {Oxy-CO2 reforming of methane to syngas over CoOx/CeO2/SA-5205 catalyst}, journal = {Energy \& Fuel}, volume = {20}, number = {5}, year = {2006}, month = {SEP}, pages = {1753-1756}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The oxy-CO2 methane reforming (OCRM) process has been investigated over the CoOx/CeO2/SA-5205 catalyst at varying reaction temperatures (750-900 degrees C), O-2/CH4 ratios (0.3- 0.45), and space velocities (20 000 - 100 000 cm(3)/g/h). With an increasing OCRM reaction temperature, the contribution from the CO2 methane reforming reaction increased while that from methane combustion reactions decreased. Correspondingly, there was an increase in the H-2/CO ratio and a sharp decrease in reaction exothermicity. At 900 C (gas hourly space velocity = 46 000 cm(3)/g/h and O-2/CH4 = 0.4), the OCRM reaction over the CoOx/CeO2/SA-5205 catalyst was mildly endothermic with \> 90\% CH4 conversion, \> 95\% H-2 selectivity, and a H-2/CO ratio of 1.63. CH4 conversion was relatively unaffected by the O-2/CH4 ratio used in the OCRM reaction; however, CO2 conversion decreased on increasing the O-2/CH4 ratio. While H-2 selectivity was not significantly affected by the O-2/CH4 ratio, the H-2/CO ratio increased linearly with an increasing O-2/CH4 ratio. The endothermicity of the reaction was found to decrease with an increasing CH4/O-2 ratio, which can be explained on the basis of increased contribution from the methane partial oxidation reaction with an increasing O-2/CH4 ratio.

}, issn = {0887-0624}, doi = {10.1021/ef060138o}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article { ISI:000241929400015, title = {Oxy-CO2 reforming of methane to syngas over CoOx/MgO/SA-5205 catalyst}, journal = {Fuel}, volume = {85}, number = {17-18}, year = {2006}, month = {DEC}, pages = {2484-2488}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

The OXY-CO2 methane reforming reaction (OCRM) has been investigated over CoOx supported on a MgO precoated highly macroporous silica-alumina catalyst carrier (SA-5205) at different reaction temperatures (700-900 degrees C), O-2/CH4 ratios (0.3-0.45) and space velocites (20,000-100,000cc/g/h). The reaction temperature had a profound influence on the OCRM performance over the CoO/MgO/SA-5205 catalyst; the methane conversion, CO2 conversion and H-2 selectivity increased while the H-2/CO ratio decreased markedly with increasing reaction temperature. While the O-2/CH4 ratio did not strongly affect the CH4 and CO2 conversion and H-2 selectivity, it had an intense influence on the H-2/CO ratio. The CH4 and CO2 conversion and the H-2 selectivity decreased while the H-2/CO increased with increasing space velocity. The O-2/CH4 ratio and the reaction temperature could be used to manipulate the heat of the reaction for the OCRM process. Depending on the O-2/CH4 ratio and temperature the OCRM process could be operated in a mildly exothermic, thermal neutral or mildly endothermic mode. The OCRM reaction became almost thermoneutral at an OCRM reaction temperature of 850 degrees C, O-2/CH4 ratio of 0.45 and space velocity of 46,000 cc/g/h. The CH4 conversion and H-2 selectivity over the CoO/MgO/SA-5205 catalyst corresponding to thermoneutral conditions were excellent: 95\% and 97\%, respectively with a H-2/CO ratio of 1.8. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {methane, oxy-CO2 reforming, Syngas}, issn = {0016-2361}, doi = {10.1016/j.fuel.2006.04.013}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article { ISI:000243163000068, title = {Oxy-methane reforming over high temperature stable NiCoMgCeOx and NiCoMgOx supported on zirconia-haffnia catalysts: accelerated sulfur deactivation and regeneration}, journal = {Catalysis Communications}, volume = {8}, number = {3}, year = {2007}, month = {MAR}, pages = {561-564}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

NiCoMgOx and NiCoMgCeOx on commercial low surface area zirconia-haffnia catalysts have unusually high thermal stability (\>= 2000 degrees C) for syngas generation via the methane partial oxidation process (J. Catal., 233, 36, 2005). Herein we report the results on accelerated sulfur deactivation (0.74 mol\% sulfur in feed) and corresponding regeneration (at 800 degrees C in 1:1 O-2 + N-2 flow) over these catalysts. The NiCoMgCeOx catalyst, due to a larger mobility of lattice oxygen, showed a considerably higher resistance to sulfur poisoning; the higher mobility of the lattice oxygen in case of the NiCoMgCeOx catalyst may be related to the presence of CeO2. During the deactivation process, the selectivity for H-2 was decreased to a much greater extent than that for CO. Regeneration studies showed that even after complete deactivation of the catalysts, the original activity/selectivity of both the catalysts could be completely restored after a simple regeneration process. Based on their exceptionally high thermal stability, high activity/selectivity and easily regenerability, the NiCoMOx, and NiCoMgCeOx catalysts appear to be very promising candidates for the CPOM process. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Deactivation, high temperature stable, methane, Partial oxidation, Regeneration, Sulfur}, issn = {1566-7367}, doi = {10.1016/j.catcom.2006.08.007}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} }