Cryogenic separation system of using coke-oven gas to produce liquefied natural gas

The utility model discloses a cryogenic separation system of using coke-oven gas to produce liquefied natural gas, which comprises a methane-hydrogen rectifying column, a methane-nitrogen rectifying column, a feed gas cooler, a nitrogen subcooler, a first overhead condenser for the methane-hydrogen rectifying column, a second overhead condenser for the methane-nitrogen rectifying column and a bottom reboiler for the methane-nitrogen rectifying column, so that a natural gas cryogenic separation pipeline system, a hydrogen-rich recovery pipeline system and a nitrogen-rich pipeline system are formed. The cryogenic separation system further comprises a twin-stage nitrogen expansion refrigerating circulation loop for providing refrigerating capacity for the feed gas cooler and the nitrogen subcooler. The cryogenic separation system of using coke-oven gas to produce liquefied natural gas is low in cost, small in investment, stable in system, simple in operation and high in recovery rate of natural gas.