Abstract: A mixed absorbent of N,N'-bis(2-hydroxyethyl) piperazine (BHEP) and sulfolane (SUF) was developed for reducing energy consumption in desulfurization. The effects of SUF dosage and inlet SO2 volume concentration on absorption-desorption performance and regeneration energy consumption were investigated, and the synergistic mechanism between SUF and BHEP for SO2 absorption by the BHEP-SUF system was also explored. The results demonstrated that with an increase in SUF dosage, both the saturated absorption capacity (AQ) and effective absorption capacity (EQ) increased first and then decreased, while the regeneration energy consumption (Q) exhibited a continuous decrease. The higher the inlet SO2 volume concentration, the greater AQ and EQ, and the lower the regeneration energy consumption. When 5wt% SUF was added to the aqueous solution of 20wt% BHEP-4.5wt% H2SO4, the AQ and desorption efficiency (DE) were increased by 2.4% and 3.7%, respectively, after four recycling runs. Furthermore, Q was reduced by 9.0%, and the condensate was decreased by approximately 22.9% during desorption. This implied that the decrease in energy consumption was primarily attributed to the reduction in water vaporization induced by SUF. 13C NMR and 1H NMR results indicated that the protonation reaction between BHEP and H+ was not affected by SUF. Molecular dynamics simulation results showed that SUF attenuated the self-agglomeration of BHEP molecules, thereby enhancing their reactivity toward SO2. The BHEP-SUF mixed absorbent not only possesses a high SO2 absorption capacity, but also achieves low regeneration energy consumption, thus showing great application potential for SO2 capture.

Key words: N,N', -bis (2-hydroxyethyl), piperazine, sulfoxide, regenerative energy consumption, SO2 absorption, mechanism analysis

摘要： 为解决有机胺脱硫再生能耗高的问题，本研究设计了N,N'-双(2-羟乙基)哌嗪(BHEP)有机胺与环丁砜(SUF)复合吸收剂，探究了SUF用量和进气SO2体积浓度对BHEP吸收解吸性能及再生能耗的影响，以及SUF协同BHEP吸收SO2的机理。结果表明，随着SUF用量增加，饱和吸收容量和有效吸收容量均先增加后减少，而再生能耗降低；进气SO2体积浓度越大，饱和吸收容量和有效吸收容量越大，再生能耗越小。在20wt% BHEP-4.5wt% H2SO4水溶液中加入5wt% SUF后，吸收剂重复使用四次时，饱和吸收容量和解吸率分别提高2.4%和3.7%，能耗降低9.0%，解吸冷凝液减少约22.9%，这表明SUF主要通过抑制水的蒸发而降低再生能耗。13C NMR和1H NMR分析表明，SUF并未改变BHEP与H+之间的质子化反应。分子动力学模拟结果显示，SUF能减弱BHEP分子间的团聚，提高有机胺对SO2的反应活性。综上，BHEP-SUF复合吸收剂在提升SO2吸收性能的同时，还能显著降低再生能耗，具有较好的工业化应用前景。

关键词: N,N'-双(2-羟乙基)哌嗪, 环丁砜, 再生能耗, SO2吸收, 机理分析