In this paper

a non-equilibrium stage method

the differential unit method，which is suitable for the multi-stage separation technology of hydrate

is proposed to aim at separating hydrogen from H2+CH4 gas mixtures and using tetrahydrofuran as the promoter.The differential unit method is that a whole reactor is divided into a number of units whose number may converge at infinity; that is to say

every differential unit is regarded as an instantaneous reactor the moment its number converges at infinity.This method makes sure that the simulation is close to reality.A wetted column serves as the example to calculate the gas-solid composition as well as their load with the differential unit method.The effects of multi-stage separation are compared at different temperatures

pressures and flow rates.The lower the temperature is

the more highly hydrogen is purified

and the higher the pressure is

the more highly hydrogen is purified.