神华煤液化残渣的热解特性

Pyrolysis Properties of Shenhua Coal Liquefaction Residue

在TGA/SDTA851热重分析仪上,以N_2为载气,在气体流速为20 mL/min,升温速率分别为20℃/min、40℃/min、60℃/min和80℃/min,终温1100℃的条件下,进行了煤液化残渣的热解特性研究实验,得到了不同升温速率下神华煤液化残渣热解的TG和DTG曲线,表明神华煤液化残渣的热解是分两步进行的．在低温段主要是神华煤液化残渣中挥发性的气体溢出引起热解失重,在低温度段180～450℃,挥发分迅速释放；高温段则主要是一些高分子有机质的热解过程．此外,研究了粒径对热解特性的影响．研究发现,随着粒径的增加,残渣的最大挥发分释放速率逐渐减小,而最大挥发分释放速率对应的温度逐渐增加．利用Freeman-Carroll法得到煤液化残渣的动力学参数,为煤液化残渣的有效和经济利用提供理论依据．

Investigations into the pyrolysis propertiesy during pyrolysis of Shenhua coal liquefaction residue were conducted by using a thermogravimetric analysis（TGA） apparatus. The pyrolysis process of the coal liquefaction residue was investigated under a neutral atmosphere of N2 at the sweep rate of 20 mL/min, in which linear heating rate was 20 ℃/min,40℃/ min,60 ℃/min, and 80℃/rain and the final pyrolysis temperature was 1 100℃. Results were obtained that the pyrolysis process of Shenhua coal liquefaction residue was divided into two steps, low temperature section and high temperature section; most of volatile matters were quickly released in the low temperature range of 180-450℃. Chemical reaction kinetic parameters and pyrolysis properties of Shenhua coal liquefaction residue were gained under different heating rates. In all experiments, as the heating rate increased from 20 to 80 ℃/min, the maximum devolatilization rate and the temperature were corresponding to the increasing peak rate.