Abstract: The desulfurization performances of piperazine-based organic amines were studied experimentally by the dynamic absorption of SO₂ from the simulated flue gas in a packed column and the solvent was thermal regenerated. The evaluation was done for a number of organic amines, including piperazine (PZ) and its derivatives N,N'-bis (2-hydroxyethyl) piperazine (BHEP), N,N'-bis (hydroxypropyl) piperazine (HPP), 1-(2-hydroxyethy) -4-(2-hydroxypropyl) piperazine (HEHPP), 1-(2-hydroxyethy) piperazine (HEP). The results of the four times absorption-desorption cycles showed that the desulfurization performances of organic amines are determined by its basic strength and steric effects. The higher pK_a of PZ, the higher absorption capacity of 0.8428mol/mol for SO₂ at the first time, but it is difficult to desorption with the first desorption rate of 78.9%, and requires the highest regeneration energy. The saturated absorption capacity decreased by 54.3% after four cycles, the cyclic absorption performance is the poorest. The saturated absorption capacity of HEP is lower than that of PZ, but its desorption performance is improved. The dihydroxy piperazine diamines with lower pK_a have relatively low the saturated absorption capacities and high desorption rates. After the 4 cycles, the average absorption capacities are not less than 0.4 mol/mol, and the average desorption rates are above 95%. Meanwhile, they have the lowest regeneration energy. The desulfurization performances of HEHPP are between those of BHEP and HPP. Therefore, the dihydroxy piperazine shows great potential for a novel desulfurization from the flue gas.

Key words: piperazine-based organic amine, desulfurization, cyclic absorption and desorption, regeneration energy

摘要： 选择哌嗪（PZ）及其衍生物N，N'-双（2-羟乙基）哌嗪（BHEP）、N，N'-双（2-羟丙基）哌嗪（HPP）、1-（2-羟乙基）-4-（2-羟丙基）哌嗪（HEHPP）、1-（2-羟乙基）哌嗪（HEP）5种哌嗪类有机胺作为SO₂吸收剂，采用动态法在填料塔中吸收模拟烟气中的SO₂并对吸收剂进行热再生。4次循环吸收解吸实验结果表明：有机胺的碱性与位阻效应共同决定其脱硫性能。PZ的pK_a最大，对SO₂有较大的吸收容量，首次饱和吸收容量高达0.8428mol/mol，但难解吸且再生能耗高，首次解吸率仅为78.9%，4次循环后饱和吸收容量下降了54.3%，循环吸收能力较差；HEP吸收效果次于PZ，其解吸性能较PZ有所提高；双羟基哌嗪类二胺的pK_a最小，饱和吸收容量相对较低，平均不低于0.4mol/mol；解吸率高，平均保持在95%以上，且再生能耗低、稳定性好，其中HEHPP的脱硫性能介于BHEP和HPP之间。因此，双羟基哌嗪可作为新型高效脱硫剂。

关键词: 哌嗪类有机胺, 脱二氧化硫, 循环吸收解吸, 再生能耗