Development and performance investigation of a biomass gasification based integrated system with thermoelectric generators

Abstract

A biomass gasification based multi-generation system integrated with thermoelectric generators is developed and proposed for cleaner applications. The paper presents, analyzes and validates a novel integration of the thermoelectric generators in the proposed biomass gasification based system and discusses the possibility of better efficiency and energy use with reduced carbon emissions. The influences of varying biomass gasification parameters are also studied against the syngas composition. The major subsystems of the integrated system, such as gasification, cryogenic air separation unit, Brayton cycle, heat recovery and domestic hot water production is simulated using Aspen plus while the Engineering Equation Solver (EES) is employed to model thermoelectric generators, proton exchange membrane electrolyzer and organic Rankine cycle. The system operating conditions and their effects on system performance are investigated. The waste heat from the thermoelectric generators is employed to the organic Rankine cycle to produce power and work generated by thermoelectric generators is employed to the proton exchange membrane electrolyzer to produce hydrogen. The amount of hydrogen produced is about 0.13 kg/day, and the amount of heating achieved by the system is 1.4 MW. Likewise, the proposed system is capable of producing 22 kg/s of hot water for the domestic purposes. The overall energy and exergy efficiencies are found to be 58.03% and 32.78%. As compared to conventional systems with thermoelectric generation, the system proposed in this study carries unique and superior characteristics.