AIR GASIFICATION OF RAILROAD WOOD TIES: INFLUENCE OF ADDITIVES ON TAR REMOVAL IN A TWO-STAGE GASIFIER

摘要

Railroad wood ties treated creosote poses a significant problem in its treatment in South Korea. In thework, air gasification of railroad wood ties treated creosote were conducted in a two-stage gasifier consisting of abubbling fluidized bed zone and a tar cracking zone with various additives in order to achieve two aims, theproduction of a high-quality producer gas having low tar and high caloric value, and the determination of the optimaloperation conditions and combination of additives for the high quality of producer gas. In the experiments, thecomparison of sand and calcined dolomite as bed materials was performed, and the effects of bottom-reactortemperature and equivalence ratio, on the producer gas composition and tar removal were investigated. Additionally,the effects of additives, activated carbon, commercial bio-char and dolomite as additives in the tar cracking zone wereexamined. As a result, the producer gas obtained with the application of dolomite as bed material and activatedcarbon in the upper reactor at an ER of 0.19 had the largest H_2 concentration about (29 vol.%) and CO content (27vol.%). Additionally, the combination of dolomite as the bed material and activated carbon in the tar-cracking zonegave the best tar removal efficiency (92%).