NOVELTY - A liquid natural gas preparation device comprises a cooling box of a heat exchanger (1, 11), where a heating device respectively connected with a mixed refrigerant compression refrigeration system and nitrogen compression refrigerating system. The heat exchanger is connected with high pressure rectifying tower through a pipeline (2), the high pressure rectifying tower and a reboiler (3), and connected with the heat exchanger through the pipeline connected with liquefied natural gas tank (4).    USE - Liquid natural gas preparing device useful for liquid natural gas from carbon monoxide and coke oven gas.    ADVANTAGE - The device is cost effective and provides high purity carbon monoxide.    DETAILED DESCRIPTION - A liquid natural gas preparation device comprises a cooling box of a heat exchanger, where a heating device respectively connected with a mixed refrigerant compression refrigeration system and nitrogen compression refrigerating system. The heat exchanger is connected with high pressure rectifying tower through a pipeline, the high pressure rectifying tower and a reboiler, and connected with the heat exchanger through the pipeline connected with liquefied natural gas tank. The rectifying tower is connected with a condensation evaporator (5) and low pressure rectifying tower (6). The evaporator is connected with a separator (7) and gas outlet pipe (8). The low pressure rectifying tower through the pipeline is connected with a condenser (9). The condenser output pipeline is connected to a tail gas output pipeline of the heat exchanger to a cooler (10). An INDEPENDENT CLAIM is included for preparing liquid natural gas and carbon monoxide from coke oven gas comprises:    (A) entering purified coke oven gas in the heat exchanger at low temperature medium of reflux cooling enters the high pressure tower for rectifying to - 150-- 170 degrees C, high pressure kettle to obtain liquefied natural gas (LNG), and cooling through the heat exchanger by throttle valve pressure to the LNG storage tank, a high pressure tower top after being extracted with hydrogen gas, nitrogen gas, and gas mixture of hydrogen and carbon monoxide through separator;    (B) discharging through the heat exchanger, where the heating liquid is super-cooling through the throttle valve and cooler, enters the low pressure rectifying tower participating rectifying the other part of the liquid to the high pressure tower top as high-pressure tower backflow liquid by gravity, low pressure rectifying tower bottom obtaining liquid carbon monoxide high pressure tower top hydrogen-nitrogen in the main condensation evaporator-carbon monoxide gas after heating;    (C) condensing low pressure rectifying tower top gas into the condenser through the heat exchanger after reheating by liquid nitrogen into liquid mixture, liquid material to low pressure tower top by gravity as reflux liquid, gas and tail gas tower top condenser evaporation of nitrogen enter into cooler for cooling mixed liquid from nitrogen-hydrogen of the high pressure tower top separator carbon monoxide tail gas out through the primary heat exchanger heating the mixed refrigerant in the main heat exchanger, the middle reboiler and heating tower lower part LNG as heat source of the high pressure rectifying tower; and    (D) providing a high pressure refrigerant after cooling the heat exchanger, after cooled to super-cooled liquid decompressed by throttle valve, where a cooling main heat exchanger heat fluid is complex heat the cold box into the mixing refrigerant compressor cycling compressed nitrogen by low temperature nitrogen compressor, it enters the main heat exchanger in cooling is cooling liquid, through liquid nitrogen throttle valve, and providing cold source is a low pressure rectifying tower condenser, after being heated by the evaporation cooler after heat circulation.    DESCRIPTION OF DRAWING(S) - The drawing is a perspective view of liquid natural gas and carbon monoxide preparation device.    Heat exchanger (1, 11)    Pipeline (2)    Reboiler (3)    Tank (4)    Evaporator (5)    Tower (6)    Separator (7)    Pipe (8)    Condenser (9)    Cooler (10)