Continuous separation of CH4/N2 mixture via hydrates formation in the presence of TBAB

Abstract

A continuous operation approach to separate gas mixture via hydrates formation was developed in this paper. We measured the formation condition of CH4/N2/TBAB hydrates, and investigated the continuous separation of CH4/N2 via hydrates formation and subsequent dissociation in the presence of TBAB. As an effective hydrate thermodynamic promotor, TBAB significantly reduces the pressure formation of CH4/N2 hydrates and enables the rapid hydration in the crystallizer at relatively low pressures. The separation effects of pressure, temperature, liquid flow, gas flow and TBAB concentration were examined. The concentration of CH4 was shown to increase from 37.5mol% to 52.4mol% in the hydrate phase after continuous separation; the concentration of CH4 in the unhydrated gas decreased to as low as 23.1mol%. The novel and significant achievement of the continuous separation of gas mixtures via hydrates formation shown in this paper is extremely useful in the potential industrial application.