关键词: 哌嗪类有机胺, 脱二氧化硫, 循环吸收解吸, 再生能耗

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