Abstract:

The low-rank coal clean conversion polygeneration system based on the three-tower circulating fluidized bed (TBCFB) is expected to improve the energy and resource utilization efficiency of low-cost coal. The process simulation software Aspen Plus was used to simulate and verify the methanol synthesis route of the polygeneration system. To improve the energy efficiency, the self-heat recuperation theory was applied to the unit of rectisol and methanol distillation. And then, the heat exchange network (HEN) was designed based on this self-heat recuperation process. The results demonstrated that the self-heat recuperation process was beneficial to the enhancement of energy utilization. Compared to the conventional process, the self-heating regeneration process saves 29.4% in the cold utility of the low-temperature methanol washing unit and 25.8% in the total energy consumption; the cold utility in the methanol distillation unit saves 69.5% and the total energy consumption 32.3%.

Key words: TBCFB, self-heat recuperation, coal to methanol, systems engineering, computer simulation, design

摘要：

以三塔式循环流化床（TBCFB）为基础的低阶煤清洁转化多联产系统有望提升低价煤的能源和资源利用效率。利用流程模拟软件Aspen Plus 对该多联产系统甲醇合成路线进行模拟和模型验证。应用自热再生理论完成了对TBCFB甲醇生产中低温甲醇洗单元和甲醇精馏单元模拟设计，并对基于自热再生的新工艺进行换热网络（HEN）设计。从能量利用效率的角度，对新工艺进行评价。结果表明，自热再生工艺与常规工艺相比：低温甲醇洗单元冷公用工程节约了29.4%，总能耗节约了25.8%；甲醇精馏单元冷公用工程节约了69.5%，总能耗节约了32.3%。

关键词: 三塔式循环流化床, 自热再生, 煤制甲醇, 系统工程, 计算机模拟, 设计