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

Abstract

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 kWe/400 kWth). 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.