Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report October 1 1993 December 31 1993 written by and published by . This book was released on 1993 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes results on the oxidative coupling of methane on three metallo-oxide catalysts. Results are reported for LaCoO3, LaNiO3 and LaRhO3 both in unpromoted and in promoted forms. The effect of the metal/oxide ratio and the method of preparation is also reported. It is found that among this three catalysts, the selectivity varies from total combustion, to partial oxidation to CO, and to oxidative coupling depending on the promoter, reaction conditions and method of preparation.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report January 1 1993 March 30 1993 written by and published by . This book was released on 1993 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes studies conducted during the past quarter on the partial oxidation of methane on the following catalysts: vanadium phosphate, unsupported and supported on silica, and on the silica (SiO2) support. It was found that the unsupported vanadium phosphate catalyst exhibits some selectivity towards formaldehyde at relatively low methane conversions (up to 5% conversion). The selectivity decreases even further on the silica supported VPO catalyst without a significant increase in conversion. In the case of silica, the reaction temperature decreases, and the formaldehyde selectivity is higher than in the case of the VPO catalyst.
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report March 30 1993 June 30 1993 written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes studies on the partial oxidation of methane on Li promoted vanadium phosphate, unsupported and supported on silica. Our previous report summarized the results on the unpromoted form of the same catalysts. However, we found that for the same level of conversion, Li promotion increased the formaldehyde selectivity in both the unsupported and silica supported forms. So we conducted further studies to determine the role of Li and the mechanism of promotion on these catalysts.
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report June 30 1993 September 30 1993 written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes studies on the oxidative coupling of methane on metallo oxide catalysts. A previous report summarized the results on the partial oxidation of methane on Li promoted VPO4 catalysts and the role of the Li promotion on increasing formaldehyde selectivity. The results of such study have been summarized in a paper submitted for publication. Given the relatively low conversion of methane and the low formaldehyde selectivity, it was decided to continue studying the oxidative coupling of methane on metallo oxide catalysts, which was one of the objective of this project. Results are reported for a LaCoO3 and LaNiO3 both unpromoted and Li promoted.
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report January 1 1995 March 31 1995 written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report 1 October 1995 31 December 1995 written by and published by . This book was released on 1996 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes progress made on a new method of producing synthesis gas via partial oxidation of methane using a fast flow membrane reactor. Experiments were performed using a Rhodium catalyst in a traditional fixed bed reactor to provide a comparison to results that will be obtained in the membrane reactor.
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Quarterly Technical Progress Report January 1 1994 March 31 1994 written by and published by . This book was released on 1994 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: In our previous report we summarized activity -- selectivity results obtained on three metallo oxide catalysts LaCoO3, LaNiO3 and LaRhO3. It was found that although these materials were highly active for methane conversion, their selectivity varied from total combustion for the LaCoO3, to partial combustion for the LaRhO3 to C2 hydrocarbon formation for the Li promoted LaNiO3. In light of the above results, we focused on studying the Li promoted LaNiO3 catalyst using the transient techniques previously developed in our group. The effect of methane and oxygen pulses, isotopic exchange of oxygen and isotopic methane switches is reported. These experiments revealed that Li prevented the total oxidation of the hydrocarbon products being formed from methane. The role of Li is to block the rate of oxygen exchange between the gas phase and the lattice, thus inhibiting the oxidation of the C2 hydrocarbons.
Download or read book Sandheden om Liva og Hueg Den sensationelle Sag der blev behandlet for lukkede D re i Byretten Et Forsvarsskrift for vor popul re Skuespillerinde written by and published by . This book was released on 1934 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synerjy written by and published by . This book was released on 1996 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Studies of Low Temperature Catalysts for Methane Conversion Final Report September 1992 March 1996 written by and published by . This book was released on 1996 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project is to use transient techniques to study gas surface interactions during the oxidative conversion of methane. Two groups of catalysts were studied: a double oxide of vanadium and phosphate or VPO, and double oxides of Ni, Co and Rh and lanthana. The objective of the studies involving the VPO catalyst was to understand gas-surface interactions leading to the formation of formaldehyde. In the second group of catalysts, involving metallo-oxides, the main objective was to study the gas-surface interactions that determine the selectivity to C2 hydrocarbons or synthesis gas. Transient techniques were used to study the methane-surface interactions and the role of lattice oxygen. The selection of the double oxides was made on the hypothesis that the metal oxide would provide an increase interaction with methane whereas the phosphate or lanthanide would provide the sites for oxygen adsorption. The hypothesis behind this selection of catalysts was that increasing the methane interaction with the catalysts would lower the reaction temperature and thus increase the selectivity to the desired products over the total oxidation reaction. In both groups of catalysts the role of Li as a modifier of the selectivity was also studied in detail.
Download or read book Selective Methane Oxidation Over Promoted Oxide Catalysts Quarterly Technical Progress Report June 1 1993 August 31 1993 written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: At 550°C, the 1 wt % SO42−l wt % Sr/La2O3 catalyst, one of the most active catalyst for the selective conversion of methane at these moderate temperatures, showed a very good stability with a reactant mixture of CH4/air = 1/1 with GHSV = 70,040 l/kg catal/hr. During a 25 hr catalytic test, the conversion of CH4 and the C2 selectivity did not change, indicating good stability of the catalyst. At the same time, the CO2/CO ratio remained steady at about 2.2, but the C2{sup =}/C2 ratio shifted slightly with time from 0.74 to 0.68. The oxidative coupling of CH4 to C2-hydrocarbons was very sensitive at 550°C to the alteration of the CH4/air reactant ratio at GHSV = 70,040 l/kg catal/hr. It was observed that the conversion of CH4, the C2 selectivity, and the %yield of C2+ hydrocarbon products decreased very rapidly with increasing CH4/air ratio from 1 to 3-4. At the largest CH4/air ratio of 40.77 that was used utilized, the CH4 conversion was less than 0-5 C-mol%. The reverse process of decreasing the CH4/air ratio from (almost equal to)40 to 1 showed nearly reversible catalytic performance, but some deactivation was apparent at the lowest reactant ratios. The 1 wt % SO42−1 wt % Sr/La2O3 catalyst used in the experiments in which the CH4/air ratio was varied subsequently revealed a good stability in the CH4 conversion level during testing at 550°C for 15 hr (GHSV = 70,040 l/kg catal/hr and CH4/air = 1/1). Indeed, the C2+ selectivity even increased by 3 to 4 C-mol%. Increasing the temperature from 550 to 600°C resulted in a further recovery of the activity of the partially deactivated catalyst.
Download or read book Fundamental Studies of the Mechanism of Catalytic Reactions with Catalysts Effective in the Gasification of Carbon Solids and the Oxidative Coupling of Methane Quarterly Report October 1 December 31 1993 written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report covers the time period from October 1 through December 31, 1993. A description of tasks for fiscal year 1994 is included in this report. Highlights and progress of work performed during this quarter is reported in (a) catalytic steam gasification of coals and cokes; (b) oxidative coupling of methane; and (c) synthesis and characterization of catalysts. Attached to this report is a copy of a manuscript submitted to Proceeding of Fuels Technology Contractors Meeting {open_quotes}Steady-State and Transient Catalytic Oxidation and Coupling of Methane{close_quotes} by Heinemann, Iglesia, and Perry.
