富钙生物油煅烧过程中孔结构变化特性的研究

摘要

To investigate the variation of pore structure characteristic during calcium-enriched bio-oil calcination process, the thermal decomposition of calcium-enriched bio-oil ( CEB) was tested in a thermogravimetric balance. The results show that there are three reaction stages; the formation of CO2 and H2O, the decomposition of organic carboxylic acid calcium salt, and the decomposition of calcium carbonate. The calcium oxide particles obtained from decomposition and calcination of CEB were analyzed to determine the physicochemical characteristics. It can be noted from the pore structure parameters that the decomposition of organic carboxylic acid calcium salt has important influences on the pore structure of product. The cavitation by gas release and the carbonization deposition of macromolecular compound coexist in the temperature range of 450 ℃ ~ 600 ℃, but the latter is dominated. The carbonization deposition of macromolecular compound mainly occurs in the range of 500 ℃ ~ 600 ℃. After 600 ℃, with the decomposition of calcium carbonate and the release of carbon dioxide, new micropores are formed in calcined product. Under the same calcination temperature, the pore characteristic of CEB calcined product is obviously superior to that of calcium carbonate.%在热重分析仪上进行富钙生物油煅烧实验。结果表明，富钙生物油的煅烧过程分为三个阶段，分别是生物油部分组分的脱CO2和H2O阶段、有机酸钙盐分解阶段、碳酸钙分解阶段。其中，有机酸钙盐分解对煅烧产物的孔结构有重要影响。在450℃～600℃，气体析出的气蚀作用与生物油中高分子化合物的碳化沉积现象同时存在，两者共同作用，但后者占主导，高分子化合物的碳化沉积主要发生在500℃～600℃。600℃以后，碳酸钙开始分解，释放出CO2，气蚀作用使煅烧产物内部形成新的微孔，产物具有发达的孔结构。相同煅烧温度下，富钙生物油煅烧产物的孔隙特性明显优于CaCO3。