Design and development of a 20 kW cleaning and cooling system for a wood-chip gasifier

Abstract

The present study was undertaken with the objectives to develop a filter system for a 20 kW engine application and to test the filter. It was observed that tar content in the gas ranged from 12.4 to 85 mg/m3 , which was considered on the higher side, in some cases, compared from an accepted limit of 50 mg/m3 . The 20 kW cleaning and cooling system for cleaning of producer gas was developed by calculating the gas flow and maximum retention time in the filter. The diameter of these three filters, viz., water scrubber, wet filter and dry filter was calculated from retention time and velocity in the filter, which was found to be 0.20, 0.40 and 0.50 m respectively, with filter height of 0.80 m. The developed filter was evaluated for reduction of tar in the producer gas after cleaning. The tar content in the producer gas after filtration by using the system varies from 24 to 53.52 mg/m3 . The tar absorption using this filter system was 99.35%, while the pressure drop varied between 10 to 25 mm of the water column. The system was also operated by coupling with a small capacity IC engine. The diesel replacement was found to be in the range of 65.66 %.