一种低能耗捕集CO_2煤基甲醇和电力联产过程设计  

Design of a coal based methanol and power polygeneration process with low energy consumption for CO_2 capture

作　　者：黄宏[1] 杨思宇[1] 

机构地区：[1]华南理工大学化学与化工学院,广东广州510640

出　　处：《化工学报》2017年第10期3860-3869,共10页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2014CB744306)~~

摘　　要：传统的煤制甲醇过程所需合成气的氢碳比为2.1左右,而煤气化粗合成气氢碳比仅为0.7左右,因此需要将部分合成气进行变换来调节氢碳比。然而,变换气与未变换气混合后使得CO_2浓度降低,从而导致CO_2捕集能耗增加。提出了一种低能耗捕集CO_2煤基甲醇和电力联产过程。新联产过程中部分粗合成气首先经过变换,将CO转变为H_2和CO_2,CO_2浓度提高,在此时进行CO_2捕集可实现捕集能耗的降低。经CO_2捕集后,得到富H_2气体,富H_2气体分流后与另一部分煤气化粗合成气混合调节甲醇合成的氢碳比。对新的过程进行了建模、模拟与分析。结果表明相比传统的带CO_2捕集的煤制甲醇和IGCC发电过程,新的联产过程的能量节约率可达到16.5%,CO_2捕集能耗下降30.3%。The molar ratio of H2/CO required is around 2.1 for the methanol synthesis of the coal-to-methanol （CTM） process. However, the H2 to CO ratio of the crude syngas is only about 0.7. It is necessary to convert part of CO and H2O into H2 and CO2 by water gas shift reaction. While mixing of the shifted syngas and the unshifted syngas results in reduction of CO2 concentration, this leads to the high energy consumption for CO2 capture. A coal based methanol and power cogeneration process with low energy consumption for CO2 capture is proposed. The CO of the crude syngas is partly converted into CO2 and H2, and the shifted syngas does not mix with the unshifted syngas. The CO2 concentration in the shifted syngas is thus relatively high compared to conventional CTM process. The energy consumption for CO2 capture is reduced as a result. The H2 rich syngas after CO2 capture is partly mixed with the unshifted syngas to adjust the composition of methanol feed gas. System analyses are made based on process modeling and simulation. The energy saving ratio of the proposed process reaches 16.5%, and energy consumption for CO2 capture is reduced by 30.3%.

关 键 词：联产 CO2捕集 甲醇 能耗 

分 类 号：TQ536.1[化学工程—煤化学工程]