PLANT AND METHOD OF EXTRACTING ETHANE FROM NATURAL GAS USING CASCADE COOLING Russian patent published in 2019 - IPC C07C7/00 C07C7/04 C10G5/06 F25J3/02 

FIELD: refrigerating equipment.

SUBSTANCE: disclosed is an plant for extracting ethane from natural gas using cascade cooling, which comprises a refrigerator, a low-temperature separator, a demethanizer, a deethanizer, a heat exchange system with propane or propylene and a heat exchange system with ethylene, wherein the coolant natural gas outlet element is connected to the low-temperature separator; with the low-temperature separator liquid phase outlet element, the demethanizer, the deethanizer, the deethanizer condenser, the deethanizer reflux tank, heat exchange system with propane or propylene and a heat exchange system with ethylene; gas phase from the upper part of the demethanizer is successively passed through a cooler, an expander and a compressor of the obtained gas; an outlet element for natural gas of the heat exchange system with ethylene is connected to an inlet element in the upper part of the demethanizer; propane or propylene compressor, propane or propylene condenser and heat exchange system with propane or propylene are connected to form a circulation circuit; an ethylene compressor, a heat exchange system with propane or propylene and a heat exchange system with ethylene are connected to form a circulating circuit. Also disclosed is a method of extracting ethane from natural gas using an plant which is described above using cascade cooling.

EFFECT: providing relatively low pre-cooling temperature and increasing the volume of ethane production using "cascade cooling + cooling in expander" technology, used at varying pressure of incoming gas, as well as provide low power consumption and simplify the design to facilitate operation of the plant.

9 cl, 1 dwg