The invention relates to a method for extracting
helium from
natural gas through a membrane process. The method is used for extracting
helium in
natural gas and comprises the following steps: carryingout
dehydrogenation pretreatment on feed gas by using a first dehydrogenator to obtain first gas; enabling the first gas to sequentially pass through
multiple stages of permeable membranes, and sequentially performing
helium separation on the first gas by using the
multiple stages of permeable membranes to obtain crude helium; conveying the crude
helium gas to a second dehydrogenator, and carrying out
dehydrogenation post-treatment on the crude
helium gas by using the second dehydrogenator to obtain second gas; and purifying the second gas to obtain helium. According to the method for extracting helium from
natural gas through the membrane process, the permeable membranes are adopted,
partial pressure differences of gas on the two sides of the permeable membranes function as driving force, and the purpose of
gas separation is achieved through transfer rate differences, generated through the steps of
dissolution,
diffusion, analysis and the like, of components. Compared with a mode ofextracting helium by adopting a low-temperature condensation method in related technologies, the method provided by the invention does not need a low-temperature environment and can be carried out atnormal temperature, and therefore,
energy consumption is effectively reduced.