Study And Process Simulation On New Technology Of Biomass Tar Removal

Here studied a new tar removal technology. This approach solved fouling related problems by reducing the dew point of tar to levels below the lowest expected temperature and avoided waste water condensation by remaining the exit temperature of tar removal process above the dew point of the water steam in the syngas.New technology used two scrubbing liquids to remove tar. Liquid 1 acted as the medium to collect heavy tars, and the light tars were absorbed by Liquid 2. Heavy tars did not dissolve in Liquid 1, which is regenerated by separating. Liquid 2 with the dissolved tars is regenerated by air stripping. The circulation of scrubbing liquid in this technology reduced investment and saved resource.Pilot plant test of new technology was on pack columns. The height of them is 6m, the diameter is 0.5m, and the pack height is 1.5m. Flow rate of syngas is 1000m~3/h, which of scrubbing liquid is 8m~3/h. The result showed that tar removal rate could reach to 99%. It was concluded that this new technology could remove tar from biomass syngas successfully.Based on ASPEN PLUS software, the simulations of the tar removal technology were performed in this study with RK-SOAVE property method and RadFrac model as columns. By designing calculation methods, the factors which affected the tar removal rate were analyzed. Results of absorbing-stripping process were obtained such as that when flow rate of scrubbing liquid increased, tar removal rate would not increase continually but have a peak value instead; when flow rate of stripping air increased, tar removal rate increased and reached a steady degree.