36.バイオマスの部分酸化によって製造した酢酸カルシウムによる石炭の高温乾式脱硫に関する研究

抄録

This paper first aims to evaluate the possibility of producing organic calcium through use of pyroligneous acid and raw limestone. The factors affecting the reaction above was discussed including the particle size of limestone, pyroligneous acid type and other parameters such as reaction temperature and time. Secondly, two low-ranked coals were mixed with the calcium-enriched pyroligneous acid to evaluate the possibility of in situ desulfurzation using the organic calcium produced via the reaction mentioned above. The experimental results suggest the feasibility of reaction between pyroligneous acid and limestone at mild conditions, which is obviously controlled by the pyroligneous acid type, i.e., its acidity. The soluble calcium within pyroligneous acid is mainly in form of calcium acetate, which has a low decomposition temperature of ca. 400℃, far less than that of raw limestone being ca. 700℃. Since of its solubility, calcium within pyroligneous acid was more readily loaded on the coals, forming the particles less than 0.5μm in the impregnated coal matrix. During coal combustion, the loaded calcium first underwent quick decomposition, the formed ultrafine calcium then reacted with the evolved sulfur, which led to formation of much gypsum having size around 1.0μm. As a result, the desulfurization efficiency more than 80% was obtained after the complete combustion of impregnated coals.