FIELD: gas production.
SUBSTANCE: equipment for extracting hydrocarbons from natural gas to produce LNG. The plant for deethanisation of main natural gas and production of liquefied natural gas by low-temperature fractionation is described, including a drying unit installed on the line of main natural gas, a recuperative heat exchanger, a reducing device and a demethaniser with upper and lower heat and mass transfer sections, as well as a unit for producing liquefied natural gas (LNG) comprising a cooler, a reducing device and a separator with an LNG outlet line and a separation gas line with a cooler, while the top of the demethaniser is equipped with a dry stripped gas outlet line, the lower heat and mass transfer section is connected by a line for supplying a part of the main natural gas as a heat carrier to the main natural gas line before and after the recuperative heat exchanger, and the bottom of the demethaniser is connected by a demethanised condensate supply line to the fractionation unit, which is equipped with product outlet lines, methane-containing gas and refrigerant input/output lines; a separator is installed on the main natural gas line between the recuperative heat exchanger and the reducing device, connected to the demethaniser by the separation residue outlet line with the reducing device; section of the demethaniser, adjoining lines of input/output of refrigerant and output of methane-containing gas, as well as a recuperative heat exchanger, on the line of production gas, a recuperative heat exchanger of production gas, a compressor, a refrigerator, a carbon dioxide purification unit, a recuperative heat exchanger of production gas and an LNG production unit are sequentially located, while at least one reducing device is made in the form of an expander connected to a compressor. A plant for deethanisation of main natural gas and production of liquefied natural gas by low-temperature fractionation is described, including a drying unit installed on the line of main natural gas, a recuperative heat exchanger, a reducing device and a demethaniser with upper and lower heat and mass transfer sections, as well as a unit for producing liquefied natural gas (LNG) comprising a cooler, a reducing device and a separator with an LNG outlet line and a separation gas line, while the top of the demethaniser is equipped with a dry stripped gas outlet line, the lower heat and mass transfer section is connected by a line for supplying a part of the main natural gas as a heat carrier to the main natural gas line before and after the recuperative heat exchanger , and the bottom of the demethaniser is connected by a demethanised condensate supply line to the fractionation unit, which is equipped with product outlet lines, methane-containing gas and refrigerant input/output lines, on line m main natural gas between the recuperative heat exchanger and the reducing device, a separator is installed, connected to the demethaniser by a line for the separation residue output with a reducing device, on the dry stripped gas output line, the following are sequentially located: adjoining the production gas line, reducing device, cooler of the LNG production unit, adjoining the separation gas line, the upper heat and mass exchange section of the demethaniser, the connections of the refrigerant input/output lines and the methane-containing gas output, as well as the recuperative heat exchanger, the recuperative product gas heat exchanger, compressor, refrigerator, carbon dioxide purification unit, recuperative production gas heat exchanger and LNG production unit are sequentially located on the production gas line, wherein at least one reducing device is made in the form of an expander connected to the compressor.
EFFECT: reduced load on the carbon dioxide purification unit for the gas to be purified and for CO2.
2 cl, 2 dwg
