NOVELTY - The device comprises a cooling box of a heat exchanger (1), and a heating device. The heating device is connected with a mixed refrigerant compression refrigeration system and nitrogen compression refrigerating system. The heat exchanger is connected with a high pressure rectifying tower through a pipeline (2), a reboiler (3) and a liquefied natural gas tank (4). The high pressure rectifying tower is connected with a condensation evaporator (5) and a low pressure rectifying tower. The condensation evaporator is connected with a separator and a gas outlet pipe.    USE - The device is useful for preparing liquid natural gas and carbon monoxide from coke oven gas.    ADVANTAGE - The device is capable of reliably, economically and efficiently preparing the liquid natural gas and carbon monoxide with high purity and reduced energy consumption in an environmentally friendly manner.    DETAILED DESCRIPTION - The device comprises a cooling box of a heat exchanger (1), and a heating device. The heating device is connected with a mixed refrigerant compression refrigeration system and nitrogen compression refrigerating system. The heat exchanger is connected with a high pressure rectifying tower through a pipeline (2), a reboiler (3) and a liquefied natural gas tank (4). The high pressure rectifying tower is connected with a condensation evaporator (5) and a low pressure rectifying tower. The condensation evaporator is connected with a separator and a gas outlet pipe. The low pressure rectifying tower through the pipeline is connected with a condenser. A condenser output pipeline is connected to the tail gas output pipeline of the main heat exchanger to the cooling box. The mixed refrigerant compression refrigeration system comprises a mixed refrigerant compressor. The mixed refrigerant compressor is connected with the main heat exchanger by mixing refrigerant pipeline from the mixing refrigerant extracted in a middle of the main heat exchanger. The re-boiler is connected with the mixed refrigerant compressor. An outlet of the mixed refrigerant is connected to the main heat exchanger through the pipeline. A heating medium pipeline forms a circulation. The nitrogen compression refrigerating system comprises a nitrogen compressor. The nitrogen compressor is connected with the main heat exchanger. The cooling nitrogen pipeline is connected with the condenser through a throttle valve. A nitrogen pipeline outlet from an air outlet of the condenser is connected with the over-cooler. The cooling box is connected with the nitrogen compressor from the medium pipeline of the over-cooler outlet to form circulation.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a device for preparing liquid natural gas and carbon monoxide from coke oven gas.    Heat exchanger (1)    Pipeline (2)    Reboiler (3)    Liquefied natural gas tank (4)    Condensation evaporator. (5)