哌嗪基离子液体吸收SO2稳定性及机制探讨OACHSSCD

To address the long-term stability of piperazine-based ionic liquids in industrial flue-gas desulfurization,N,N'-bis(2-hydroxyethyl)piperazine(BHEP)-based ionic liquids were subjected to degradation in a high-temperature,high-pressure reactor.The effects of temperature,time,and sulfur dioxide(SO2)loading on degradation were investigated using gas chromatography(GC),gas chromatography-mass spectrometry(GC-MS),and Fourier-transform infrared spectroscopy(FT-IR).The thermal degradation products and oxidative thermal degradation products of ionic liquid were analyzed,and the degradation mechanisms were clarified.The results indicate that SO2 loading is the pivotal factor influencing degradation,exerting a far greater effect than temperature and time on the degradation process.Under identical conditions,oxidative-thermal degradation is more severe than thermal degradation.At a constant temperature of 130 ℃,the addition of 2％(mass ratio)potassium formate(HCOOK)and a 6 h degradation period reduced the thermal and oxidative-thermal degradation rates by 5.08％and 10.9％,respectively,significantly enhancing cyclic stability.Thermal degradation produces of the ionic liquid are N-(2-hydroxyethyl)piperazine(HEP)and triethylenediamine(TEDA),while oxidative thermal degradation yields solely TEDA.These degradation products increase the SO2 absorption capacity by 54.96％and 43.97％,respectively.