半焦床层温度对煤-半焦耦合热解制取低温焦油的影响

Effects of Carbocoal-bed Temperature on Production of Low Temperature Tar by Coal-carbocoal Coupled Pyrolysis

以半焦在相对高温下发生缩聚反应析出的氢作为氢源,在同一反应器内实现了煤-半焦耦合条件下的含氢气氛煤解聚过程,研究了半焦床层在不同温度(650℃,700℃和750℃)下对煤热解产物分布及其品质的影响.结果表明:耦合热解(CSP)过程较单煤热解(CP)过程的焦油产量增加,且随着半焦床层温度的升高而逐渐增大,750℃时焦油收率提高了16%.焦油模拟蒸馏实验表明,耦合热解过程的焦油中轻质组分含量增加,沥青组分含量显著减少,半焦床层温度在650℃(CSP650),700℃(CSP700)和750℃(CSP750)时,CSP过程沥青含量比CP过程沥青含量分别降低了28.83%,40.77%和44.28%.焦油的GC×GC-MS联用实验表明,耦合热解焦油的芳香环侧链取代结构物质含量增加.原煤半焦的TG-MS实验表明,半焦在高温热解时由于发生裂解、缩聚反应而析出H_2和CH_4,这是本研究中加氢热解的氢源.

The hydrogen produced from condensation reaction of carbocoal at relatively high temperature were utilized by implementing the coal-depolymerization process in hydrogen rich atmosphere under the condition of coal-carbocoal coupling in the same reactor.The effects of the carbocoal bed temperatures（650℃,700℃and 750℃）on the distribution and quality of the coal pyrolysis products were studied.The results show that the tar yield in coupled pyrolysis process（CSP）increases compared with that in the single coal pyrolysis（CP）.The tar yield gradually increases with the increase of temperature of the char bed,and it increases by 16% at 750℃.The simulated distillation of the tar shows that the light components increase,while the content of asphalt component in CSP decreases by 28.83%,40.77% and 44.28% at the carbocoal bed temperature of 650℃,700℃and 750℃compared with that in CP,respectively.The GC×GC-MS of tar indicates that during the coupling pyrolysis process,the aromatic compounds with side chain increase.The TG-MS data of carbocoal from raw coal shows that H2 and CH4 are precipitated by pyrolysis and polycondensation of the char at high temperature,which supplies the hydrogen in this process.