Structural studies of nanosized porous membrane catalytic systems highly active in dry reforming of biomass conversion products

Abstract

The structures of porous ceramic membrane catalytic systems exhibiting high activity in dry reforming of biomass conversion products (methane, hydrocarbons C 2 -C 4 , and alcohols) to a hydrogen containing gas were studied. The membrane catalytic systems represent porous inorganic membranes (supports) prepared by self propagating high temperature synthesis and modified by nanosized metallocompex components, which are uniformly distributed in the internal pore volume. Structural studies were carried out using scanning electron microscopy with energy dispersive analysis, transmission electron microscopy, temperature programmed reduction with hydrogen, and X ray diffraction analysis.Considerable attention is recently given to the develop ment of efficient methods for the conversion of natural gas and renewable biomass to syn gas and dihydrogen, which are among the major energy carriers in petroleum chemis try and power engineering. 1-3 It has previously been shown that the dry reforming and vapor reforming of methane, its gaseous homologies, alcohols, and a series of carboxylic acids (primary products of biomass conversion) are sub stantialy intensified in porous membrane catalytic sys tems (MCS). These systems have a very low content of active components distributed on the internal surface of the membrane channels. 4-6 However, they exhibit high specific productivity in the formation of syngas in dry reforming of methane and ethanol. Syn gas production increases if a mixture of ethanol and glycerol (50%) mixture is used as raw materials. 7 The productivity of syn gas for the process in the membrane catalytic reactor increases by almost an order of magnitude compared to that attained when dry reforming is carried out in a tra ditional flow type reactor with the loaded stationary cata lyst bed of a similar composition obtained by grinding the MCS. 4-7As shown in many works, the improved heat exchange and mass transfer of the substrates in membrane channels are important advantages of such systems compared to the stationary catalyst bed loaded in a traditional flow type reactor. 8,9* Dedicated to Academician of the Russian Academy of Sciences R. Z. Sagdeev on the occasion of his 70th birthday.