Experimental Study on Dual Air Supply Downdraft Gasifier for anImproved Producer Gas Quality

摘要

Tar reduction is a major technical challenge which needs to be addressed in biomass gasifier systems. This study presents an experimental evaluation of dual air supply downdraft gasifier with respect to better producer gas quality in terms of reducedtar and particulate content. Experiments were conducted by varying the secondary air flow from 15 to 30 % at constant equivalence ratio of 0.4. The secondary air flow was optimized at 25 % with tar content of 241 mg Nm 1 and lower calorific value of 4.51MJ Nm3. The dual air supply in the gasifier allowed a reduction of 79 % tar content as a result of partial oxidation of volatile compounds in the pyrolysis zone.