Separation of carbon dioxide using emulsion liquid membrane containing methyldiethanolamine and 2-amino-2-methyl-1-propanol siti

Abstract

Carbon dioxide (CO2) removal is important in industry to optimize the capital and the operating costs of a process, to meet gas specifications and also for environmental purpose. The most developed CO2 capture technology that the separation process can be easily adapted to the existing plant is pre-combustion capture. In natural gas industry, amine absorption method is widely used in pre-combustion capture technology (sweetening) to remove the CO2 from natural gas. However, due to amine corrosive nature, alternative is needed for CO2 separation. Therefore, emulsion liquid membrane (ELM) was introduced to overcome the corrosion problem. However, separation ability of emulsion needs to be investigated. In this study, water in oil (w/o) emulsion was prepared. 2-amino-2-methyl-1-propanol (AMP) and methyldiethanolamine (MDEA) in sodium hydroxide solution form an aqueous phase. The organic phase consists of a mixture of kerosene and Span-80 as surfactant. In this study, the effects of amines mixture concentration, Span-80 concentrations and retention time on CO2 absorption capacity were investigated. ELM was prepared by homogenizing the aqueous phase into the organic phase at speed of 10 000 rpm for 5 minutes. For CO2 absorption study, 200 ml of ELM was tested in a rotating disc contactor column with the supply of 20 psig CO2/CH4 gas mixture. The stability of the MDEA-AMP emulsion was determined and the CO2 absorption by the emulsion was measured. This study showed that using 8% v/v MDEA and 4% v/v AMP with 6% v/v Span-80, 64.98% of CO2 was removed at the emulsion stability of 78.00%. This study also proved that the presence on amines did not lead to any corrosion of the stainless steel.