A Novel Compact Bio-filter System for a Down-draft Gasifier: An Experimental Study

A major problem in biomass gasification is tar formation which in subsequent stages decomposes under the conditions such as temperature, pressure drop, gas flow rate etc. The potential of proposed compact Bio-filter for gas cleaning system analyzed here is excellent for reducing the tar content and particulate in producer gas. Critical review of literature reveals that all existing system have a maximum tar removal capacity of 90%. However, an exemption, catalytic crackers have efficiency in the range of 90 to 95%,but it operates at very high temperatures (900 °C).In this work, an attempt has been made to develop an efficient comapct filter system and analyze its performance characteristics that operates in a low temperature range of 50-70 °C, which will be convincing when compared with other system. The performance of developed compact Bio-filter was successfully tested with a 20 kW open core downdraft TNAU-SPRERI's gasifier. Results claim maximum tar reduction rate, than any other system reported and its magnitude varies from 93% -97%. Moreover, the experimental results reveals that tar and particulate content is converged to 52 mg/Nm3 from an initial range of 1680 mg/Nm3 claiming an efficiency of 97%, thereby useful for reducing the engines wear and tear.