Experimental investigation of a multi-stage air-steam gasification process for hydrogen enriched gas production

To achieve hydrogen-rich and low-tar producer gas, multi-stage air-blown and air-steam gasification processes were studied in this research. Results showed that the tar content from multi-stage air-blown and air-steam gasification were lower, compared to the average value of that from downdraft gasification. In the cases of air supplies of 80, 100l min(-1) and 100, 100 l min(-1) with steam, hydrogen yields were increased by 40.71 and 41.62%, respectively, compared to that without steam. These were about 1.6 times of hydrogen flow rate of the base case (S/B = 0). However, it was found that too much steam added to the process was disadvantageous. The equilibrium model was also applied to predict the hydrogen production and the composition of producer gas obtained from the multi-stage air-blown and air-steam gasification processes. The predicted result showed a better match for the case of multi-stage air-blown gasification process. Copyright (C) 2010 John Wiley & Sons, Ltd.