Hydrogen Generation by Gasification of Rice Husk in an Integrated Fuel Cell Processor

Abstract

Fuel processing is defined as conversion of any biomass, hydrocarbons or organics to a fuel gas reformate suitable for fuel cell (FC) anode reaction system. Rice husk is one of the potential organic sources of hydrogen and heat energy that can be generated from rice husk gasification processes. The high-purity hydrogen fed to the FC stack for power generation makes waste rice husk utilization system economically and environmentally attractive. Thus, the main objectives of this work were to develop a rice husk gasification process and the potential applications of high-purity hydrogen from syngas (CO and H2) on stationary power generator of FC system. In the lab-scale fixed-bed and bench-scale downdraft experimental approaches, gasification of rice husk was accompanied by a substantial production of syngas at 760–900 K. It was found that in addition to over 90% of syngas generation, approximately 7.17 × 105 kcal/hr of thermal energy was recovered and the cold gas efficiency was 78–86% when the gasifier was operated at O/C atomic ratios between 1.1 and 1.3. The product syngas can be further separated by pressure swing adsorption and Pd membrane purification units, which effectively purified and generated 99.999% pure hydrogen in an integrated FC Processor. Finally, cost or benefit analysis of a rice husk gasifier of 10-TPD (tons per day) was also performed to confirm the economic potential for such a recycling practice and determine if further development of stationary FC system would be warranted.