Abstract:

China’s energy structure determines the coal based methanol production route. The traditional coal-to-methanol process has the problems of low energy efficiency and high energy consumption of CO₂ capture. In order to reduce energy consumption and CO₂ emission, and improve energy efficiency, a new coal-to-methanol process based on chemical looping air separation and hydrogen technology was proposed. The chemical looping air separation technology can replace the cryogenic air separation unit of traditional coal-to-methanol process, and reduce energy consumption to a certain extent. The integration of chemical looping hydrogen production technology can replace the water-gas shift device and greatly reduce the energy consumption of CO₂ capture; moreover, chemical looping hydrogen production technology can also produce hydrogen for adjusting the hydrogen to carbon ratio of syngas. In this paper, the parameters of the core units of the new process were optimized and the whole process was simulated. Based on the simulation, the performance of the new process was analyzed. The results show that the energy consumption of air separation and CO₂ capture is reduced by 41% and 89%, respectively, comparing with the traditional coal-to-methanol process. At the same time, the energy efficiency of the new process is increased by 18% and the CO₂ emission is reduced by 45%.

Key words: chemical looping air separation, chemical looping hydrogen production, coal-to-methanol, parameters optimization, performance analysis

摘要：

我国能源结构决定了以煤为主的甲醇生产路线。传统煤制甲醇过程主要存在过程能量效率低、CO₂捕集能耗高等问题。本文提出了一种化学链空分联合化学链制氢的煤制甲醇新过程，以降低能耗、二氧化碳排放及提高能源效率。化学链空分技术的集成可以替代传统煤制甲醇过程的空气分离单元，并在一定程度上降低能耗。化学链制氢技术的集成，一方面可以替代水煤气变换装置，并且可以极大程度降低二氧化碳捕集能耗；另一方面，化学链制氢技术还可生产用于调整合成气氢与碳比的氢。本文对新过程的核心单元进行了参数优化以及全流程的模拟，基于模拟对新过程的性能进行了分析，结果表明新过程与传统的煤制甲醇过程相比，空分和二氧化碳捕集能耗分别降低了41%和89%。同时，新过程的能量效率提高了18%，二氧化碳排放量降低了45%。

关键词: 化学链空分, 化学链制氢, 煤制甲醇, 参数优化, 性能分析