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为研究CaO对褐煤和无烟煤热解特性影响,采用实验室小型固定床反应器对锡林郭勒褐煤(X)和宁夏石嘴山无烟煤(SH),进行热解实验,研究了CaO对热解三相产物分布规律影响。实验结果表明:在500~600℃时,添加2%CaO后褐煤热解生成CO_2的产率小于未添加CaO煤样热解生成CO_2的产率,添加CaO与否对其他3种气体H_2,CH_4,CO产率影响不大;与未加入CaO的褐煤煤样相比,加入CaO的褐煤煤样在相应温度下热解气相产物产率小幅度降低,且随着热解温度的升高,加入CaO的褐煤煤样气相产物产率增加速率大于未加入CaO的褐煤煤样。褐煤脱挥发分主要在600℃之前的热解阶段,而对于无烟煤来说,CaO在中温热解阶段对挥发分的脱除具有促进作用。对于褐煤半焦来说,加入2%CaO一直作为灰分存在半焦中,且随着热解温度的升高,褐煤半焦在高温时反应活性较高,发生热缩聚反应,导致半焦中有机质含量降低,以上2种原因直接导致褐煤半焦灰分升高;对于无烟煤来说,灰分增加主要是由于CaO的加入。
In order to study the influence of CaO on the pyrolysis characteristics of lignite and anthracite coal, pyrolytic experiments were carried out on Xilin Gol lignite (X) and Ningxia Shizuishan anthracite (SH) using a small fixed-bed reactor. The distribution of pyrolysis three-phase products influences. The experimental results show that the yield of CO_2 produced by pyrolysis of lignite is lower than that of pyrolysis of coal without addition of 2% CaO at 500-600 ℃, , And the yield of CO was not affected. Compared with the lignite without CaO, the yield of pyrolysis gas products decreased slightly with the addition of CaO, and with the increase of pyrolysis temperature, The rate of increase of the yield of the gas products of the lignite from CaO is higher than that of the lignite from which CaO is not added. Lignite devolatilization mainly in the pyrolysis stage before 600 ℃, and for anthracite, CaO in the mid-temperature pyrolysis stage of volatilization to promote the role. For lignite semi-coke, 2% CaO was always present in the semi-coke as ash, and with the increase of pyrolysis temperature, the semi-coke coke at high temperature had higher reactivity and thermal condensation polymerization reaction, resulting in the semi-coke organic matter Content decreased, the above two kinds of reasons directly led to lignite brown coal ash increased; for anthracite, the increase of ash is mainly due to the addition of CaO.