Performance prediction of a decentralized power plant (120 kWe) using a multi-particle model of a downdraft biomass gasification process

摘要

A one-dimensional model of a downdraft biomass gasifier is presented to investigate the effect of operating parameters on the performance of a power plant. The approach considers the biomass fed to the reactor by employing discrete particle size distribution (DPSD) to simulate the real operational conditions of a gasification power plant (120 kW(e)/400 kW(th)). Char production (byproduct) and producer gas (PG) flow are the targets of the model; the model has been validated using data from an industrial power plant (biomass consumption, pressure drop, and PG composition) with an average relative error of 1.8%. The model achieved stable and reliable results using DPSD for 16 different particle sizes. The increase in the mean biomass particle diameter (15-60 mm) diminished the PG power (363.8-285.3 kW) and the cold gas efficiency (CGE) (63.2-54.36%) because of low particle surface/volume ratio. When biomass moisture content increased (5-25 wt%), the PG power decreased (364.14-318.75 kW) because of low gasification temperature. Moreover, when the number of driven engines was increased from 2 to 5 (electric power), the CGE decreased (68.17-59.17%) due to the low residence time of the solid and gas phases, which inhibited the gasification reactions, in the reactor.