煤低温热解与直接液化联产系统研究

煤低温热解和直接液化之间具有很多耦合要素，提出将两者集成联产系统，用煤气制氢替代煤气化制氢来降低成本、用煤焦油作补充溶剂油实现提质加工、将液化残渣与煤共热解提取高附加值油品，实现各副产物综合利用，达到系统价值最大化。基础实验研究表明，神东长焰煤与液化残渣（煤渣质量比为95∶5）共热解焦油干基产率约为8.0%，煤气有效成分大于85%；为使共热解过程不结块，液化残渣掺入量应小于30%。模拟计算表明，百万吨级煤直接液化与千万吨级煤低温热解联产，可以省却煤气化制氢及空分装置，系统能量转化效率达到75%以上，协同效应显著。

Study on cogeneration system for coal low-temperature pyrolysis and direct liquefaction processes

A lot of coupled factors exist between coal low-temperature pyrolysis and direct liquefaction processes.A cogeneration system for coal low-temperature pyrolysis and direct liquefaction was proposed in this paper.The cogeneration system will produce hydrogen via pyrolysis gas conversion instead of coal gasification to reduce cost，use coal tar as supplementary solvent oil to upgrade the coal tar，and use coal liquefaction residue and coal as mixed feed for co-pyrolysis to produce value-added oil products.The comprehensive utilization of its own by-products makes this system operation yield optimal values.Basic co-pyrolysis experimental studies show that the tar yield is about 8% (dry base) when Shendong long-flame coal and liquefaction residue (coal/residue mass ratio 95∶5) are used.The useful components of pyrolysis gas account for more than 85%.To prevent the blocking of the co-pyrolysis process，the mass ratio of liquefaction residue vs.coal should be maintained below 30%.Computer simulation was conducted on the system and the simulation results show that coal gasification and air separation processes could be eliminated for a million tons level coal direct liquefaction process if it is integrated with a ten-million tons level coal low-temperature pyrolysis process.The energy conversion efficiency of such a cogeneration system could reach a 75% plus range，an obvious synergistic effect.