Highly Selective H(2) Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications. (Annual Technical Report, September 2003-September 2004).

Hong, M. ; Noble, R. D. ; Falconer, J. L.

Technical Information Center Oak Ridge Tennessee

关键词: Coal gasification;    Hydrogen;    Progress report;    Research projects;    Ion exchange;   

RP-ID  :  DE2006861659

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

It is desirable to develop inorganic zeolite membranes that are capable of highly selective H(sub 2) separation from other light gases (CO(sub 2), CH(sub 4), CO). Zeolite membranes are thermally, chemically and mechanically stable, and have tunable molecular sieving and catalytic ability. These unique properties make zeolite membrane an excellent candidate for use in catalytic membrane reactor applications related to coal conversion and gasification, which need high temperature and high pressure range separation in chemically challenging environment where existing technologies are inefficient or unable to operate. In an effort to develop zeolite membranes more suitable for H(sub 2) separation, various types of zeolite membranes were modified. The aim of the modification is to tune the size of zeolite pores and/or to decrease the number of defects within as-synthesized zeolite membranes. The modification attempts include silylation on Al-ZSM-5, B-ZSM-5 and SAPO-34 membranes, and ion exchange of SAPO-34 membranes. Results show that silylation on B-ZSM-5 membranes with low Si/B ratio give the best hydrogen separation membranes in terms of H(sub 2) separation selectivity and high temperature stability. For one B-ZSM-5 membrane after silylation, the H(sub 2)/CO(sub 2) separation selectivity at 473 K increased from 1.4 to 37, whereas the H(sub 2)/CH(sub 4) separation selectivity increased from 1.6 to 33. However, silylation decreased H(sub 2) permeances more than one order of magnitude in the B-ZSM-5 membrane. The H(sub 2) permeance and H(sub 2)/CO(sub 2) and H(sub 2)/CH(sub 4) separation selectivities increased with temperature. At 673 K, the H(sub 2) permeance was 1.0OE10(sup -7) mol-m(sup -2)-s(sup -1)-Pa(sup -1), and the H(sub 2)/CO(sub 2) separation selectivity was 47. This is the second annual technical progress report for the university coal research program supported by U.S. DOE NETL (Contract No. DE-FG26-02NT41536). This report summarizes program accomplishments up to December 2004. The report includes an introduction summarizing the research objectives and tasks; it also provides a summary of program activities and accomplishments covering progress in various zeolite membrane synthesis and modification. Possible future work is proposed as well.