NATURAL GAS LIQUEFACTION METHOD “ARCTIC MIX” Russian patent published in 2023 - IPC F25J1/00 

FIELD: natural gas liquefaction.

SUBSTANCE: methods for liquefying natural gas for its further transportation by river and sea transport. The prepared natural gas is compressed, the heat of compression is removed and cooled by three circuits of mixed refrigerants, the pressure of the cooled gas is reduced to form a vapor-liquid mixture, and the liquefied gas is removed. In each circuit, the mixed refrigerant is compressed, the heat of compression is removed, it is supercooled, its pressure is reduced to obtain a low-pressure mixed refrigerant in each circuit and used to cool natural gas. In the primary circuit, the first mixed refrigerant is supercooled by evaporating the first low pressure mixed refrigerant. In the second circuit, the second mixed refrigerant is also cooled by evaporating the first low pressure mixed refrigerant and supercooled by evaporating the second low pressure mixed refrigerant. In the third circuit, the third mixed refrigerant is cooled by evaporating the second low pressure mixed refrigerant and supercooled by evaporating the third low pressure mixed refrigerant. It is possible to pre-cool the third mixed refrigerant by evaporating the first mixed refrigerant. At the same time, the end point of boiling of the second mixed refrigerant at the pressure of the beginning of its compression is lower than the temperature of the first mixed refrigerant after its pressure is lowered, and the end point of boiling of the third mixed refrigerant at the pressure of the start of its compression is lower than the temperature of the second mixed refrigerant after its pressure is lowered.

EFFECT: more stable operation of the unit.

5 cl, 2 dwg