(459e) The Conceptual Framework and Modeling Analysis of Compact Energy Systems

The conceptual frame work for compact energy system is presented to make energy from a biomass like wood/switchgrass, as an alternative to the construction of large scale biorefineries. The compact energy system consists of four individual components: biomass preparation, biomass converter, fuel reformer, and powered-engine. The individual unit processes within each component and the possible types of compact energy systems with different biomass converter technologies like fermentation, pyrolysis, and gasification are presented. The size, weight, and energy efficiency of upgrading biomass to energy using compact energy system with various gasification technologies have estimated. For a compact energy system with the hydrogen fuel cell as a powered-engine component and that processes 10 kg of dry biomass per day, the net energy (kWh) of compact energy system is found to be -7.5, -30, 18.7, 13.1, and 11.7 with the super-critical, microwave assisted, catalytic, steam, and conventional gasification technologies as biomass converter technologies, respectively. The low yields of super-critical gasification and a low efficacy of converting electric energy to heat via electromagnetic waves with the microwave assisted gasification are results in such negative net energy with the respective compact energy systems. Finally, the challenges and opportunities with the development of compact energy systems built around gasification are discussed.