Study On The Selective Desulfurization Performance Of Sterically Hindered Amines

In order to decrease the comsumption of desulfurizer in the field of industry in 21st century, human beings need develop desulfurizer which could effectively selective removal H₂S from natural gas which has high CO2 content. Nowadays, in alcohol-amine desulfurization methods, a new desulfurizer named sterically hindered amine ?SHA? has been widely used for its high selective desulfurization capability. In this paper, we study the relationship of H₂S absorptivity and selective desulfurization with reaction time in different conditions systemically. Moreover, the relationship between SHA's molecular structure and selective desulfurization performance was also studied.In this research, we investigate H₂S absorptivity, selective desulfurization and regeneration performance of three SHA aqueous solutions including TBE ?2-?tert-butylamine?ethanol?, TBEE ?2-tertiarybutylamino-2-ethoxyethanol? and AMP ?2-amino-2-methyl-l-propanol?, and a tertiary amine MDEA ?N-Methyldiethanolamine?. By using static method, CO2 and H₂S mixture gases were filled in reaction kettle which contains amines aqueous solutions to study the relationship of H₂S absorptivity and selective desulfurization capacity with reaction time. In this experiment, the amine mass fraction and absorption temperature are experimental variables and the performance of SHA was compared with MDEA. As the result, the H₂S absorptivity and selectivity of all amine aqueous solutions increased at the beginning and then dropped with the increase of reaction time. Selective desulfurization of SHA is not good when amine mass fraction is 10% or 20% and the performance is better than MDEA while amine mass fraction is 30%. MDEA and TBE have better selective desulfurization in 25?, while TBEE and AMP are better in 35?. The effect of regenerative time on regenerative performance of these amines aqueous solutions was also studied. The results show that TBE solution still has good performance after 2h regeneration. Moreover, TBEE and AMP are regenerated 1h to keep good performance and MDEA still has good performance after 3h regeneration.