METHOD OF PRODUCTION OF LIQUEFIED NATURAL GAS Russian patent published in 2018 - IPC F25J3/08 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the gas processing industry. By means of the filter, natural gas is purified from mechanical impurities and a dropping liquid. Then, pre-drying of the gas is carried out in the membrane unit. Permeate is sent to a low pressure pipeline. Gas after the membrane unit is adsorptively cleaned and dried using three adsorbers, each of which is filled in the course of the feed stream with an adsorbent for drying and purification from carbon dioxide and then an adsorbent for purification from hydrocarbons C₃ and above and from nitrogen. In the first adsorber, partial dehydration and gas purification is carried out, in the second adsorber, drying and gas purification is performed until the normative parameters are reached, and the third adsorber is in regeneration mode. If the normative parameters are exceeded in the gas after the second adsorber, the first adsorber is converted to the third adsorber mode, the second adsorber to the first adsorber mode, and the third one to the second adsorber mode. Liquefaction of the gas is carried out at the end of the adsorption process. Flow of the unexpected gas is used to regenerate the adsorbents and as the purge gas of the membranes of the membrane unit.

EFFECT: technical result consists in separating the thermal front of adsorption, in optimizing the adsorption properties of the adsorbents used and the sequence of their loading.

1 cl