Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-1AUTOTHERMAL SORPTION-ENHANCED STEAM REFORMING OFHYDROCABONS WITH SUPERADIABATIC COMBUSTIONSORBENT REGENERATIONA.N. Zagoruiko, A.G. Okunev, S.N. TrukhanBoreskov Institute of Catalysis, pr.Lavrentieva, 5, Novosibirsk, 630090, Russia;fax -7-383-3307678; e-mail: zagor@catalysis.ruActive development of hydrogen-based energy technologies is in a great extent limitedtoday by availability of efficient and low-cost hydrogen production. The most promisingtechnological way in this direction is application of sorption-enhanced catalytic methanesteam reforming. This approach, first formulated even in 19-th century [1], has received a lotof attention in modern practice since 1980-s and now is developing extremely fast bynumerous research groups worldwide [2-5].The sorption-enhanced catalytic methane steam reforming concept except usual methaneand carbon monoxide steam conversion catalytic reactions, widely applied in conventionaltechnologiesСН 4 + Н 2 О СО + 3 Н 2 (1)СО + Н 2 О СО 2 + Н 2 (2)also includes the adsorption of product СО 2 by solid sorbent, e.g. calcium oxide:CaO + СО 2 -> CaСО 3 (3)leading to favorable equilibrium conditions for reactions (1), (2) and to achievement of highyield of high-purity hydrogen in one conversion stage. After saturation of sorption capacity ofthe sorbent it is necessary to provide its regeneration according to reactionCaСО 3 -> CaO + СО 2 (4)Though the research efforts in this area are very intensive and active, the achieved levelof process efficiency is still far from ideal. While performance of basic reaction cycle(reactions 1-3) is well studied and more or less optimized, the source of most complications issorbent regeneration reaction stage (4). The major attention in current developments isconcentrated on application of mixed catalyst-sorbent fixed beds with so called «isothermal»sorbent regeneration, meaning external bed heating during regeneration stage. Such heatingapproach is characterized with high level of inefficient energy losses. Moreover, efficient anduniform heating of the bed in this case is possible only in reactors with relatively smalldiameter and this factor limits the scale of approach application or requires unreasonablecomplication of reformer design. Much more promising, but much less studied, regeneration397