生物质型煤的热解特性研究

Study on pyrolysis characteristics of bio-briquette

为开拓低阶粉煤资源的高效分质利用途径,以长焰煤粉煤和生物质为主要原料,制备了生物质热解型煤,采用热重分析和固定床热解试验研究了其热解特性,并与原料粉煤进行了对比。结果表明：型煤相比原煤更易于发生热分解反应,其最大热失重速率峰温相比原煤减小;在失重率小于60%（热解温度低于503℃）时,型煤热解活化能高于原煤,失重率高于60%时,其活化能低于原煤;型煤和原煤的热解活化能主要分布在200-300、150-250 k J/mol;型煤在较低温度下热解对焦油具有较高的选择性,在高温下热解更有利于生成气体产物;型煤热解气体产物组成及其随热解温度的变化规律与原煤基本一致,但型煤热解气体中CO2的含量较原煤高0.5倍左右。

In order to explore an efficient utilization way for low rank pulverized coal,a bio-briquette was prepared with a long flame pulverized coal and biomass,and its pyrolysis behaviors were investigated by a thermal gravimetric analyzer and a fixed bed reactor,and were compared with those of the raw coal. The results show that the briquette is easier to be decomposed,and its temperature to the maximum weight loss rate is lower than that of the raw coal. The activation energy of the briquette pyrolysis process is higher than that of the raw coal when the weight loss rate is lower than 60%（ the temperature is lower than 503 ℃）,while the situation is opposite when the temperature exceeds 503 ℃. The activation energies of briquette and raw coal pyrolysis are mainly distributed in 200 - 300 k J / mol and 150 - 250 k J /mol respectively. It＇s more favorable for the briquette pyrolysis to form liquid product under relatively low temperature and to form gaseous product under relatively high temperature. The composition of the gas product from briquette pyrolysis is similar with that from the raw coal except that the content of CO2,which is almost 0. 5 times more than that of the raw coal.