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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation and improvement of dehydrogenation conversion and isomerization selectivity in an extractor catalytic membrane reactor /

Van Dyk, Lizelle Doreen. January 2005 (has links)
Thesis (PhD)--University of Stellenbosch, 2005. / Bibliography. Also availabe via the Internet.
2

Catalytic fixed bed membrane reactor operation for hydrocarbon conversion processes

Althenayan, Faisal M., School of Chemical Engineering & Industrial Chemistry, UNSW January 2006 (has links)
Dry/CO2 reforming is one the hydrocarbon processes that recently has been interesting due to it is ability of producing a lower synthesis gas ratio (H2/CO). This synthesis gas is a highly significant product since it costs more than 50% of the total capital cost of gas to liquid (GTL) process. However, since this reaction is thermodynamically limited, higher temperature or lower pressure is required to achieve higher conversion. Typically, reaction temperatures between 1073 and 1173 K are used for catalytic dry reforming reactions. Consequently, these extreme temperatures lead to a severe carbon deposition causing a catalyst deactivation which is the major difficulty related to CO2 reforming reaction. This has pushed the efforts to be focused mainly on the development of new catalysts. In fact, dry reforming of propane is an equilibrium-limited reaction which can be shifted to the product side by removing one of the products out of the system which can be achieved using a selective membrane reactor. This research is dedicated to investigate and study the catalytic performance of dry reforming of propane over cobalt-nickel catalyst under the temperature range of 773-973 K. This bimetallic catalyst supported on ??-Al2O3 has been utilized in this research since it exhibits better activity, selectivity, and deactivation resistance than monometallic catalysts. Based on this, the primary aims of this thesis are to examine this catalyst and to study the impact of using membrane reactor. In addition, the reaction mechanism and kinetic are investigated using a fixed-bed reactor. Experimental observations have exposed that the catalyst is offering good results under this reaction. The catalysts analysis has confirmed the presence of metal oxides in the catalyst. However, only at a lower carbon dioxide to propane ratio, i.e. lower than 3.5, a carbon signal has been reported. The activation energy study indicates that the process is unlimited by diffusion. The reaction order for propane and carbon dioxide has been found to be zero and 1.17 respectively. This in turn has indicated that C3H8 activation reaction is taking place rapidly and carbon dioxide is suggested to be involved in the rate determining step. In membrane reactor operation, the production rates for H2 and CO have been reported to increase as the sweep gas flow rate increases. The co-current mode offers higher production rate and more stability than counter-current mode over the range of feed ratio. On the other hand, fixed bed reactor shows stable performance and produces more CO and H2 for both modes.
3

Membrane's properties and potential operational savings for a membrane reactor system versus a conventional reactor system in propylene production

Angueira, Ernesto J. 12 1900 (has links)
No description available.
4

Catalytic fixed bed membrane reactor operation for hydrocarbon conversion processes

Althenayan, Faisal M., School of Chemical Engineering & Industrial Chemistry, UNSW January 2006 (has links)
Dry/CO2 reforming is one the hydrocarbon processes that recently has been interesting due to it is ability of producing a lower synthesis gas ratio (H2/CO). This synthesis gas is a highly significant product since it costs more than 50% of the total capital cost of gas to liquid (GTL) process. However, since this reaction is thermodynamically limited, higher temperature or lower pressure is required to achieve higher conversion. Typically, reaction temperatures between 1073 and 1173 K are used for catalytic dry reforming reactions. Consequently, these extreme temperatures lead to a severe carbon deposition causing a catalyst deactivation which is the major difficulty related to CO2 reforming reaction. This has pushed the efforts to be focused mainly on the development of new catalysts. In fact, dry reforming of propane is an equilibrium-limited reaction which can be shifted to the product side by removing one of the products out of the system which can be achieved using a selective membrane reactor. This research is dedicated to investigate and study the catalytic performance of dry reforming of propane over cobalt-nickel catalyst under the temperature range of 773-973 K. This bimetallic catalyst supported on ??-Al2O3 has been utilized in this research since it exhibits better activity, selectivity, and deactivation resistance than monometallic catalysts. Based on this, the primary aims of this thesis are to examine this catalyst and to study the impact of using membrane reactor. In addition, the reaction mechanism and kinetic are investigated using a fixed-bed reactor. Experimental observations have exposed that the catalyst is offering good results under this reaction. The catalysts analysis has confirmed the presence of metal oxides in the catalyst. However, only at a lower carbon dioxide to propane ratio, i.e. lower than 3.5, a carbon signal has been reported. The activation energy study indicates that the process is unlimited by diffusion. The reaction order for propane and carbon dioxide has been found to be zero and 1.17 respectively. This in turn has indicated that C3H8 activation reaction is taking place rapidly and carbon dioxide is suggested to be involved in the rate determining step. In membrane reactor operation, the production rates for H2 and CO have been reported to increase as the sweep gas flow rate increases. The co-current mode offers higher production rate and more stability than counter-current mode over the range of feed ratio. On the other hand, fixed bed reactor shows stable performance and produces more CO and H2 for both modes.
5

Optimising catalyst and membrane performance and performing a fundamental analysis on the dehydrogenation of ethanol and 2-butanol in a catalytic membrane reactor /

Keuler, Johan Nico. January 2000 (has links)
Dissertation (PhD)--University of Stellenbosch, 2000. / Bibliography. Also available via the Internet.
6

Experimental and modeling studies on a catalytic packed bed membrane reactor

Deshpande, Ashutosh G. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 1998. / Title from document title page. "June 1998." Document formatted into pages; contains viii, 115 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 92-94).
7

Batch reactors for scalable hydrogen production

Damm, David Lee. January 2008 (has links)
Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Andrei Fedorov; Committee Member: Srinivas Garimella; Committee Member: Timothy Lieuwen; Committee Member: William Koros; Committee Member: William Wepfer. Part of the SMARTech Electronic Thesis and Dissertation Collection.
8

Transport of gases across membranes /

Mokrani, Touhami. January 1900 (has links)
Thesis (MTech (Chemical Engineering))--Peninsula Technikon, 2000. / Word processed copy. Summary in English. Includes bibliographical references. Also available online.
9

Simulation of a membrane reactor for ammonia decomposition /

Kraisuwansarn, Nichakorn. January 1991 (has links)
Thesis (M.S.)--Oregon State University, 1992. / Typescript (photocopy). Includes bibliographical references (leaves 82-85). Also available on the World Wide Web.
10

Biological removal of natural estrogens in membrane bioreactors /

Lee, Sally Yin Chun. January 2009 (has links)
Includes bibliographical references (p. 179-208).

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