Gasification of different types of fuels with steam and oxygen produces a synthesis gas (syngas) which consists mainly of CO, H2, CO2 and H2O. Depending on the fuel and the operating conditions, the contents of CO and H2 in the syngas usually range from 35% to 55% and from 20% to 45% respectively. If higher hydrogen contents are desired, the Water Gas Shift (WGS) reaction allows the conversion of CO to H2 and CO2 in presence of excess steam and a specific catalyst. This reaction is industrially carried out in two consecutive stages, first a high-temperature step for rapid CO conversion and then a low-temperature step for achievement of lower equilibrium CO contents. A novel approach which is being investigated to increase the production of hydrogen in gasification processes is the use of a Water Gas Shift (WGS) membrane reactor in which a single high-temperature WGS catalyst is combined with a hydrogen selective membrane. In this system, the removal of hydrogen from the reaction chamber through the membrane drives the WGS reaction to the products side and thermodynamic equilibrium can be exceeded. Catalyst and membrane must be carefully chosen and special attention must be paid to operating conditions in order to guarantee the correct performance of the system. In this work the performance of semi-commercial palladium membranes and two different high temperature WGS catalysts are described and the advantages of using a WGS membrane reactor for the production of H2 in gasification processes versus a conventional WGS reactor are presented.© 2012 Nova Science Publishers, Inc. All rights reserved.
|Title of host publication||Gasification: Chemistry, Processes and Applications|
|Publisher||Nova Science Publishers, Inc.|
|Publication status||Published - 2011|
All Science Journal Classification (ASJC) codes
Basile, A., Blasi, A., Fiorenza, G., Iulianelli, A., Longo, T., & Calabrò, V. (2011). Membrane and membrane reactor technologies in the treatment of syngas streams produced from gasification processes. In Gasification: Chemistry, Processes and Applications Nova Science Publishers, Inc..