Comparative Analysis Between Different Configurations in a Biomass Gasifier and a Genset for Electrical Energy Production

Abstract

The effect of different gensets coupled to a downdraft, fixed bed gasifier was investigated, pruning residue from five different tree species was used. This gasifier was designed to power a dual (produced gas/diesel) engine, with a maximum power electric generation of 20 kWe. This engine was first replaced by a four-cylinder engine, and later by a six-cylinder diesel engine, which underwent a conversion process for the Otto cycle; it was thus possible to operate the genset only with produced gas. This modification allowed an increase in the produced electric power from 20 kWe to 32 kWe. To operate this engine only with the produced gas, without harming its capacity to generate electric power, it required many modifications, as an increase in motor supply pipe diameter. Also, due to excessive accumulation of ash on the grate that separates the reactor core from the ash deposit, a mechanical system that clears this grate has been installed. This device allows gases produced in the gasification to have a continuous flow through the grate, being manually operated whenever required. In order to evaluate the viability of this new set gasifier/genset, some parameters such as consumption, power output, and system efficiency were studied, and a comparison was made with the data generated by works previously done by the same laboratory team and using the same gasifier.