METHOD FOR LIQUEFYING NATURAL GAS (OPTIONS) Russian patent published in 2022 - IPC F25J1/02 

FIELD: cryogenic technology.

SUBSTANCE: inventions relates to the field of cryogenic technology. The method for liquefying natural gas includes cleaning and drying the initial natural gas and cooling it in a plate-fin heat exchanger until a two-phase flow is formed, which is removed from the heat exchanger and separated into gas and liquid fraction in the separator, the liquid fraction is sent for utilization, the gas is returned from the separator to the heat exchanger for its liquefaction and supercooling by means of an external closed nitrogen-expander cycle. Nitrogen is compressed, cooled, divided into two streams, and each stream is additionally compressed to different pressure values in the compressor stages of the first and second turbo-expander-compressor units. Each nitrogen stream is cooled and fed into a heat exchanger, in which nitrogen streams with different pressure values are cooled to different temperatures, removed from the heat exchanger and sent for expansion to the expander stages of the turboexpander-compressor units. Cold flows of low-pressure nitrogen are sent to a heat exchanger for heat exchange with a flow of liquefied natural gas and high-pressure nitrogen flows.

EFFECT: reduction of specific energy consumption for the production of liquefied natural gas and simplification of the control process of the liquefied natural gas plant.

3 cl, 3 dwg, 1 tbl