Experimental Study of the Pyrolytic Gasification of a Biomass Downdraft Type Gasifier

With a biomass downdraft type gasifier serving as the object of study and the rice stalk particles as the raw material,through an experimental study,analyzed were changes in the temperature distribution inside the gasifier and the influence of the gasification temperature on the fuel gas constituents of the products,fuel gas heating value,gas pro-duction capacity and efficiency. It has been found that the temperature in the oxidation zone increases from 500 ℃to 800 ℃,the hydrogen content increases by 12. 23%,the CH4 content increases by 98% and the total fuel gas content increases from 15% to 34%. The heating value of the fuel gas will increase according to a linear law with an increase of the temperature. When the temperature is 800 ℃,the heating value of the fuel gas will slightly decrease after attaining its maximum value of 6. 76 MJ / Nm3. The magnitude of the heating value is mainly influenced by the magnitude of the CH4 content. After the operation of the gasifier has been stable,the gasification efficiency will be in a range from 71. 64% to 76. 64%,thus enjoying a good adaptability to the fuels having big densities and high heating values such as biomass particles and attaining relatively ideal gasification performance.