Pressure-swing adsorption process to purify or analyse a gas stream

摘要

Three or more adsorber vessels undergo cyclic operation: Adsorption - the gas flows through one or more vessels in parallel, at the highest process pressure; cleaned or analysed gas is removed at their exit. Pressure reduction - pressure in the vessels is then reduced in parallel, in a number of stages, the gas being used to build up the pressure in other adsorber vessels. Evacuation - at the end of pressure reduction, evacuation follows. Pressurisation - the adsorption pressure is restored by multi stage pressurisation using gas from pressure reduction, as well as added make-up gas and/or product gas. The desorption of residual gas components is carried out during the evacuation phase. It is achieved, preferably by a series of separately imposed, multiple, vacuum and pressurisation conditions.