氧/燃料燃烧条件下高钙煤灰的碳酸盐化研究

Carbonation of High-calcium Coal Ashes Under Oxy-Fuel Combustion Conditions

利用水平管式炉对两种高钙煤灰在氧/燃料燃烧条件下的碳酸盐化特性进行了研究,重点探究了H_2O和SO_2浓度对煤灰碳酸盐化反应的影响规律,并利用HSC Chemistry对实验现象进行了合理解释。研究结果表明,在无SO_2的情况下,H_2O的存在促进了煤灰的碳酸盐化反应,且碳酸盐化程度随H_2O浓度的增大而增大;在相同H_2O浓度下,SO_2的加入对煤灰的碳酸盐化反应具有强烈抑制作用,且H_2O浓度越高,这种抑制作用越明显;同时,SO_2存在条件下,煤灰中Ca的反应程度明显降低。

Carbonation of high-calcium coal fly ashes was investigated under O_2/CO_2 combustion conditions on a horizontal tube furnace.It focused on the effects of H_2O and SO_2 concentrations.The observed phenomena were reasonably explained by using the HSC Chemistry software.The results showed that,in the absence of SO_2,ash carbonation was enhanced by the addition of water vapor.And the carbonation extent increased with increasing the volume fraction of H_2O.At the same H_2O level,the addition of SO_2 significantly suppressed the carbonation process.This inhibitory effect was more pronounced at higher H_2O levels.The presence of SO_2 apparently inhibited the reaction of calcium in coal fly ashes.