Gasification of Furniture Waste Sawdust in a Cyclone Gasifier

Abstract

Sawdust is one of the major biomass that was produced over 1 million ton per year in Thailand. A large amount of sawdust can be used as renewable energy. Gasification is one of the high-efficiency processes to convert biomass to the gaseous product. Sawdust is suitable to be converted to the gaseous product due to its high proportion of volatile (73%). In this work, sawdust thermal conversion was investigated by using a stairmand type cyclone gasifier with 100 mm diameter. The operation of the cyclone with short residence time and high efficiency of particulate separation from the gaseous product is suitable for a small particle like sawdust. The influences of equivalence ratio (0.15-0.60) and reactor temperature (700°C, 800°C and 900°C) on the waste conversion performance were determined. The gas composition (CO, CO2, CH4, H2, and CnHm), carbon and hydrogen conversions, lower heating value and cold gasification efficiency were reported. The data analysis indicated the optimum equivalence ratio is 0.45. Excessively lower or higher equivalence ratio negatively affected the gas composition and heating value of gaseous product. The optimum of reactor temperature is 900°C. The lower temperature also adversely affected the gaseous product, conversion of carbon and hydrogen. The lower heating value of product gas is range from 0.95-3.45 MJ/m3 and the cold gasification efficiency is range from 28-68%. The optimal condition of sawdust gasification in cyclone gasifier is equivalence ratio of 0.45 and temperature of 900°C at which total carbon and hydrogen conversionsare 90% and 60%, respectively.