Feasibility of simulated biomass tar removal by a self-cooling coupled with absorption technology

Tar removal is one of the bottlenecks to the large-scale industrialization and commercialization of biomass gasification technology. A Self-Cooling Coupled with Absorption Technology (SCCAT) was developed and patented. Cyclohexane and n-dodecane were used as the simulated light and gravimetric tar respectively, and an online gas chromatograph method for measuring their concentrations was established. Absorbents for cyclohexane were selected. The simulated tar removal feasibility were investigated by a self-proposed test rig of the SCCAT. The results show that, modified diesel is recommended as the best absorbent for cyclohexane. Both cyclohexane and n-dodecane after the SCCAT can be reduced to 1%, providing a total removal efficiency of 98%, at a cooling temperature and absorption temperature of 35 °C and 30 °C respectively. It takes both of cooling and absorption effects in the cooler on cyclohexane removal. Cyclohexane concentration out of the absorber can be dropped to lower than 1%. The coolant recovery can be recycled succesfully. The modified diesel can be regenerated effectively with a regeneration capacity of 90% after being purged for 125 min at 50 °C. The SCCAT has proved to be feasible for deep removal of simulated tar.