Abstract:
A series of formed active cokes for SO2 removal in flue gas was prepared from fly char and its parent coal with two steps: the carbonization of raw briquette in N2 flow at different temperatures between 400 ℃ and 700 ℃ and the activation of the carbonized product at 900 ℃ in a stream of N2+H2O. The effects of carbonization temperature on pore properties (BET surface area, micropore area and volume, pore size distribution) and other physical and chemical properties (yield, mechanical strength, sulfur capacity and iodine value) were investigated. The results show that the carbonization temperature plays an important role in preparation process. Among those parameters, the mechanical strength is close related to carbonization temperature, which increases with increasing carbonization temperature, whereas there is little effect of temperature on gross yield. In addition, other parameters (BET area, sulfur capacity, etc.) decrease with increasing carbonization temperature with different degree. In the meantime, pore size distribution of active coke produced at lower carbonization temperature is relatively reasonable. The optimal carbonization temperature range is 600 ℃~700 ℃, under which the prepared active coke exhibits the properties comparable to those commercial ones and could meet the requirements for desulphurization.