Temperature effect on continuous gasification of microalgal biomass: theoretical yield of methanol production and its energy balance

A microalga, Spirulina, was partially oxidized at temperatures of 850 degrees C, 950 degrees C, and 1000 degrees C, and the composition of produced gas was determined in order to evaluate the theoretical yield of methanol from the gas. The gas composition depended on the temperature, and the gasification at 1000 degrees C gave the highest theoretical yield of 0.64 g methanol from 1 g of the biomass. Based on this yield, the total energy requirement for the whole process including the microalgal biomass production and conversion into methanol was obtained. Energy balance, which was defined as the ratio of the energy of methanol produced to the total required energy, was 1.1, which indicates that this process was plausible as an energy producing process. The greater part of the total required energy, almost four-fifth, was consumed with the microalgal biomass production, suggesting that more efficient production of microalgal biomass might greatly improve its energy balance. (C) 1998 Elsevier Science B.V. All rights reserved.