Investigation into a catalytically controlled reaction gasifier (CCRG) for coal to hydrogen

Energy demands will increase as industrialized nations strive to maintain progress and productivity gains and as developing nations increase their consumption and productivity. One direction that is evolving to satisfy the demand while minimizing environmental impacts is to move toward a hydrogen economy. For the foreseeable future, the majority of these demands will be met through the increased usage of fossil fuels. One of the most abundant and readily available fuels is coal. This realization has raised some questions about the responsible use of such a fuel and as such it is critical that a Greenhouse Gas Management strategy/technology be developed to forestall projected global warming and its impacts. The technology presented in this paper involves a novel form of coal gasification to convert coal to useful forms of energy while addressing environmental concerns. The technology, which is a form of steam reforming, focuses on the combining of catalytic combustion with coal gasification to generate H-2 and CO from coal while yielding a CO2 sequestration ready stream. The H-2 can either be separated from the CO or used as an IGCC turbine fuel. Using an Aspen Plus simulation shows that with a steam to carbon ratio of 1.5 provides a hydrogen output of 1.15 kg/h while generating about 14 kW of electricity (for every 1 kmol/h of carbon fed to the reformer) from a SOFC using the portion of the CO generated which was not needed to drive the reforming reactions. Additionally, recycling up to 25% of CO2 into the reformer produces about 15% more hydrogen, while using 20% less CO for combustion to drive the gasification reactions. Because of the Boudouard reaction an extra 32% (4.5 kW per kmol/h of carbon) can be generated from an SOFC operating on the CO not used for combustion. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.