Experimental and simulation of single equilibrium stage separation of (methane + hydrogen) mixtures via forming hydrate

To separate gas mixture through forming hydrate is a new technology, which might be applicable in recovering economically valuable gas components, such as hydrogen and ethylene from refinery gases. A set of equipment was designed and constructed for the experimental study of gas mixtures separation efficiency via forming hydrate. Batch operation method with/without gas–liquid circulating can be adopted. The separation efficiency for hydrogen + methane gas mixtures in pure water, 1, and 6 mol% tetrahydrofuran (THF) in initial aqueous solution were examined at different temperature, pressure, and feed gas composition conditions. The results showed that high operation pressure is needed for separation from pure water, which is only used to the initial hydrogen enriched. With the existence of THF in aqueous solution, hydrogen was remarkably enriched in vapor phase by a single equilibrium stage, especially when 6 mol% THF added. Based on the extended Chen-Guo hydrate model, an algorithm for vapor-hydrate flash calculation was developed to simulate the single equilibrium stage separation of gas mixtures. Good predict precision can be obtained by the simulating algorithm, which was then extended to simulate the experimental conditions that cannot be achieved by the limit of device.