A novel hybrid compact filter system for a down-draft gasifier : an experimental study

Abstract

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 and retention time. The potential of proposed hybrid filter for gas cleaning system analyzed here is excellent for reducing the tar and particulate in producer gas. Critical review of literature reveals that all existing system have 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). An attempt has been made to develop an efficient hybrid filter system and analyze its performance characteristics that operates in a low temperature range of 50-70°C. The performance of developed

compact hybrid filter was successfully tested with a 20 kW open core downdraft TNAU-SPRERI’s gasifier. The concept of hybrid compact filter presented in this study, is first of its kind and it claims 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 and greatly useful for reducing the engines wear and tear. Furthermore the filter design was developed with cost benefit on commercial basis.