Effects of Secondary Air Intake Position and Gasifying Agents on Grape Branches Gasification in an Improved Downdraft Gasifier

The gasification experiment of grape branches was carried out in a self-improved downdraft gasifier at 800°C, under atmospheric pressure, using air, steam, and air-steam as gasifying agents. The effects of secondary air inlet position (0-75cm beneath the reactor’s top), ER (0.1-0.3), S/B mass ratio (0.5-2.5g/g), and S/B mass ratio (0.3-1.2g/g) with ER=0.1 on characteristics of biomass gasification were investigated. The results suggested that when the secondary air at 45cm beneath the reactor’s top, the gas yield, combustible gas concentration and CGE all reach the maximum value. The highest CGE of 59.14% was achieved when use air as gasifying agents. Increasing S/B mass ratio from 0.5 to 2.5 causes an increase in H2 content, gas yield, CCE, and CGE, but a decrease in CO content and LHV. The air addition in steam gasification process resulting in a greater gas yield, CCE, CGE, and H2 yield than pure steam gasification