Abstract:
The effect of various parameters on gas production such as flow rates of producer gas, rates of water feed, volumes of char container, sizes of wood and temperatures, was studied in a down draught moving bed with 26 centimetres inside diameter gasifier with throat of 14 and 18 centimetres diameter. Producer gas was produced from wood sizes of (0.5)3 , (1.0)3 and (1.5)3 cubic inches. We studied the effect of volumetric flow rates of producer gas from 3 to 43 cubic metres per hour and rates of water feed between 53 to 160 millilitres per minute at the lengths from char-perforate plate to thermocouple at throat of 2, 5, 10 and 20 centimetres. It was found that the temperature of the gasifier increased remarkably with increases in volumetric flow rates of producer gas because of increasing in combustion rate. It increased carbon monoxide and hydrogen concentration but decreased carbon dioxide concentration with methane concentration unaffected. Increasing the distanced between char-perforate plate and thermocouple at the throat increased the carbon monoxide concentration but decreased the carbon dioxide concentration because of increases in reduction zone. However, hydrogen and methane concentrations were unaffected. The amounts of oxygen, used in the gasification process based on one mole of carbon in wood, was decrease by increasing the volumetric flow rates of producer gas or increasing the distances between char-perforate plate and thermocouple at throat but increases in sizes of wood and rates of water feed were not affected