Experimental study of gasification rate of fast-growing willow biomass

Abstract

The biomass of fast-growing hybrid plants can be an effective source for energy conversion. The biomass of energy plants: hybrid poplar, hybrid willow etc., is a potential fuel for obtaining thermal and electrical energy. It should be noted that a small size downdraft gasifier, which is economically available and the most reliable equipment, is the most suitable for the use in small or medium production conditions for energy conversion of fast-growing willow biomass. The experimental confirmation of the mathematical model of fast-growing willow biomass gasification rate is proposed to carry out in the paper. According to the model, the rate of biomass gasification is proportional to the amount of biomass remaining ungasified. The gasification rate coefficients of four fractions of fast-growing willow biomass pieces and pellets were determined by the research results. During the research, the supply of oxidizer (air) to the working area (zone) of the downdraft gasifier was changed. When the air supply into a gasifier is minimal, the gasification rate coefficient is actually the same for all biomass fractions of fast-growing willow Salix Viminalis, L. and is 4.1·10-5 ± 0.1·10-5 s-1. With an increase in air supply the gasification rate coefficient increases and reaches its maximum value at an air supply of 9·10-3 m3·s-1, further increase in the air volume does not lead to an increase in the gasification rate coefficient. As the size of fuel pieces decreases, the rate coefficient also increases and is 9.476·10-5 s-1 for the fraction with the smallest pieces.