低温甲醇洗中尾气冷量的回收利用及工程实现

Recovery and utilization of the cold energy from Rectisol tail gas and the engineering realization

低温甲醇洗作为一种高效的气体净化工艺,近年来在流程优化、节能降耗、降低投资、提高装置灵活性等方面都得到了不断的改进。以采用水煤浆加压气化技术的某9万t/a煤制氢装置为例,结合煤化工行业低温甲醇洗放空尾气和气化单元外排灰水的特点,对该工艺流程配置进行了优化,使尾气与外排灰水进行换热,既回收了低温甲醇洗放空尾气的冷量,又降低了外排灰水的温度,达到降低成本,减少能耗的目的。借助ASPEN EDR软件,对该换热器进行了工程设计,根据计算结果对换热器的总体设计尺寸、流路分数、热阻分布、压降分布等关键参数进行了分析讨论,各参数均在合理的范围内,为煤化工企业进行类似的改造提供了参考。

As an efficient gas purification technology, Rectisol process has been constantly improved in the process optimization,energy saving, investment reduction, and device flexibility improvement in recent years. Taking a 90 kt / a coal to hydrogen unit usingwater？coal？slurry pressure gasification technology as an example, combining with the features of Rectisol tail gas and ash water discharged from gasification device in coal chemical industry, the technical process configuration is optimized by exchanging heat betweentail gas and discharged ash water. The cold energy in Rectisol tail gas is recovered, and the temperature of discharged ash water is de？creased as well by heat exchange. The optimized process can realize the goal of cost reduction and energy consumption decrease. Withthe aid of ASPEN EDR software, the engineering design of the heat exchanger is carried through, and the calculation results are used toanalyze and discuss the overall design dimensions, flow path fraction, thermal resistance distribution and pressure drop distribution ofthe heat exchanger. The parameters are all within a reasonable range, which provides a reference for similar reconstruction project ofcoal chemical industry.