部分脱灰及碱金属对煤直接液化渣热化学过程的影响

Effects of Partial Demineralization and Alkali Metals on Thermochemical Process of Direct Coal Liquefaction Residue

以煤直接液化渣为原料,利用热重分析仪,考察了部分脱灰和碱金属对其在水蒸气气氛下热化学过程的影响,并计算了气化阶段的表观活化能。结果表明:部分脱灰提高了煤直接液化渣在热解和气化阶段的转化率,降低了半焦的表观活化能,对热化学过程产生积极的影响;NaCl在热解和气化过程中均未表现出明显的催化作用;KCl在热解过程中同样没有表现出明显的催化作用,在气化阶段,则提高了半焦在低温下的气化转化率,表现出了催化作用,并使半焦的气化反应进入到了内扩散过渡区。

The effects of partial demineralization and alkali metals on the thermochemical process of direct coal liquefaction residue in steam atmosphere were investigated by thermogravimetric analyzer,and the apparent activation energy of gasification was calculated.The results show that partial demineralization increases the conversion rate of direct coal residue in the course of pyrolysis and gasification,reduces the apparent activation energy of coke,and has a positive effect on the thermochemical process.NaCl shows no obvious catalytic effect during pyrolysis and gasification.KCl also show no obvious catalytic effect in the pyrolysis process,but in the gasification stage,it improves the gasification conversion rate of coke at low temperature,shows catalytic effect on the gasification,and makes the gasification reaction of coke switches to the internal diffusion transition zone.