基于MDEA的烟气SO2捕集过程工艺参数和能量集成分析

有机胺吸收法是一种高效环保型烟气脱硫技术，而从系统工程的角度对烟气SO₂捕集工艺的分析、优化和能耗评估尚未有详细报道。对N-甲基二乙醇胺（MDEA）为吸收剂的烟气SO₂捕集过程工艺进行研究，考察了MDEA浓度、温度、SO₂解吸率对捕集效果的影响规律。结果显示，MDEA溶液浓度为30%（质量）、烟气温度不高于45℃、回流贫液温度不高于41℃时，SO₂吸收效果较好；增加SO₂解吸率是以降低解吸气中SO₂纯度和增大再沸器负荷为代价，水分汽化是再生能耗增高的主要原因。针对吸收剂再生过程能耗大的问题，采用热泵辅助精馏对解吸过程进行能量集成，吸收剂再生能耗可降低47%，年度总费用（TAC）可降低9.93%。本研究对有机胺体系的SO₂捕集系统工业化应用具有重要的指导作用。

Parameters analysis and energy integration in flue gas SO2 capture process based on MDEA

Organic amine absorption is an efficient and environmentally friendly flue gas desulfurization technology, and the analysis, optimization and energy consumption evaluation of the flue gas SO₂ capture process from the perspective of system engineering have not been reported in detail. In this paper, SO₂ capture process of flue gas was studied with N-methyldiethanolamine (MDEA) as the absorbent. The effects of MDEA concentration, temperature, and SO₂ desorption rate on the SO₂ capture were investigated. The results show that the optimized parameters for SO₂ absorption are as follows: MDEA concentration, feed temperature of flue gas and absorbent are 30%(mass), below 45℃ and 41℃, respectively. Increasing of the SO₂ desorption ratio is at the expense of the low SO₂ desorption purity and the high energy consumption of absorbent regenerative process, since water gasification is the main reason for the high energy consumption. In order to solve the problem of high energy consumption in the regenerative process, the modified process with heat pump technology was proposed. The energy consumption of absorbent regeneration can be reduced by 47%, TAC can be reduced by 9.93% in the heat pump assistant desorption process. It is expected from the study to strengthen the development of the industrial application of SO₂ capture of organic amine system.