Abstract: A method for recovering helium from a feed gas mixture comprising helium, carbon dioxide and at least one of methane and nitrogen, and wherein at least a part of the feed gas mixture is subjected to a separation sequence including a membrane-based separation and an adsorption-based separation forming a helium product, wherein the the membrane based separation is performed using a first membrane separation step and a second membrane separation step, the membrane based separation and the separation sequence includes no further membrane separation steps, the adsorption based separation is performed using a pressure swing adsorption step, at least a part of the feed gas mixture is subjected to the first membrane separation step forming a first retentate and a first permeate. A corresponding arrangement is also provided.

Abstract: The invention relates to a method for obtaining natural gas components, wherein, using natural gas, a feed mixture containing methane and helium is provided and subjected to a separating sequence so as to obtain a natural gas product which is enriched with methane and depleted of helium in comparison to the feed mixture and a helium product which is depleted of methane and enriched with helium in comparison to the feed mixture, which method comprises one or more membrane separating steps and one or more pressure change adsorption steps. According to the invention, the feed mixture is provided using natural gas containing methane, higher hydrocarbons, helium and carbon dioxide, and the providing of the feed mixture comprises depleting the natural gas used for provision of the feed mixture of carbon dioxide and of the higher hydrocarbons. The present invention also relates to a corresponding system.

Abstract: A method and to a device for producing a synthesis gas, which contains carbon monoxide and hydrogen, wherein natural gas having a first carbon dioxide partial pressure (CO2 pressure) is provided and is processed inter alia by means of a pressure increase to form a natural gas input for a thermochemical conversion, in which a synthesis raw gas having a second CO2 pressure greater than the first CO2 pressure is produced, from which synthesis raw gas at least carbon dioxide is subsequently separated in order to obtain the synthesis gas and carbon dioxide, at least some of which is returned and is used in the thermochemical conversion of the natural gas input. To separate carbon dioxide, the synthesis raw gas is conducted across the one membrane on the retentate side, which membrane is permeable to carbon dioxide and is flushed on the permeate side by the provided natural gas.