CIESC Journal ›› 2017, Vol. 68 ›› Issue (10): 3860-3869.DOI: 10.11949/j.issn.0438-1157.20170500

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Design of a coal based methanol and power polygeneration process with low energy consumption for CO2 capture

HUANG Hong, YANG Siyu   

  1. School of Chemical Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China
  • Received:2017-04-28 Revised:2017-06-14 Online:2017-10-05 Published:2017-10-05
  • Supported by:

    supported by the National Basic Research Program of China (2014CB744306).

一种低能耗捕集CO2煤基甲醇和电力联产过程设计

黄宏, 杨思宇   

  1. 华南理工大学化学与化工学院, 广东 广州 510640
  • 通讯作者: 杨思宇,cesyyang@scut.edu.cn
  • 基金资助:

    国家重点基础研究发展计划项目(2014CB744306)。

Abstract:

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%.

Key words: polygeneration, CO2 capture, methanol, energy consumption

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CO2浓度降低,从而导致CO2捕集能耗增加。提出了一种低能耗捕集CO2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H2和CO2,CO2浓度提高,在此时进行CO2捕集可实现捕集能耗的降低。经CO2捕集后,得到富H2气体,富H2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CO2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%,CO2捕集能耗下降30.3%。

关键词: 联产, CO2捕集, 甲醇, 能耗

CLC Number: