Effect of equivalence ratio on the air-gasification of swine manure

The main method of controlling pollution caused by livestock raising is waste reduction and utilization, and the thermochemical conversion technology provides a new mode for ernergy production from livestock wastes. The fluidized bed gasifier system was developped and the swine manure air-gasification experiments were carried out. This article mainly presented the effects of Equivalence Ratio(ER) on gasification process. The results showed that ER had two-sided and complicated effects on the gasification process. The alteration of ER would change the velocity of fluidizing gases in the reactor which had the remarkable influence on fluidized bed temperature distribution. The results showed that oxidation and reduction zone, as well as high temperature region, moved up in the reactor along with the increase of ER. The solid production was decreased with the increase of ER which was favorable for gasification process, but too high value of ER would increase the yield of liquid which was harmful for gasification process. The heat value of fuel gas was decreased with the increase of ER and the carbon conversion efficiency had the countertrend. The gasification efficiency had the fluctuation characteristic with the alteration of ER. The results showed that the ER setting range was around 0.25 for swine manure gasification. In practical production, it would be very important to adjust the ER according to the conditions of inner reactor’s temperature distribution, material fluidization quality and fuel gas composition.