Fuel cell power plants using hydrogen from biomass

This paper discusses a power generation system that offers high energy efficiency, ultra-clean environmental performance, and near-zero greenhouse gas emissions. Biomass from agricultural and forestry wastes or dedicated energy farms can be used efficiently for power generation in integrated biomass gasification-fuel cell (IBGFC) systems. The energy efficiency of these systems has been projected to approach 55% or even higher if cogeneration opportunities can be utilized. Such systems, in addition to being ultra-efficient, can boast very low emissions of SO{sub 2}, NO{sub x}, and particulates, and are essentially CO{sub 2}-neutral. With the mounting concern about greenhouse gas emissions, this approach to renewable energy is very attractive for small distributed generation markets in the US and worldwide. Biomass wastes alone, by current estimates, have the potential to provide as much as 338 GW of electrical power worldwide if utilized in this fashion, and offer the best near- to mid-term market entry opportunities for this technology. Power demand in the US will be driven by the opening of niche markets as a result of deregulation and environmental concerns, and markets in other regions will be driven by economic growth as well. In this paper, the integration of a pressurized fluidized-bed gasifier with amore » molten carbonate fuel cell and expansion turbine bottoming cycle will be presented. Two cycles are suggested: one using conventional technology for biomass drying, feeding, and gasification, and a second, more advanced cycle using wet feeding direct to the gasifier and in-bed steam reforming to boost cycle efficiency and reduce capital costs. Both cycles use state-of-the-art molten carbonate fuel cells with an expansion turbine bottoming cycle. These options are presented along with recommended technical development activities and targets.« less