NOVELTY - Coke-oven gas is pressurized. The obtained material is conveyed into compressor and pressurized. Carbon monoxide in compressed gas is converted into carbon dioxide and hydrogen. The desulfurized conversion gas is supplied into carbonizing device and pressure swing adsorption (PSA) decarbonizing device. The product analyzed by PSA decarbonizing device is pressurized. The obtained product and conversion gas are supplied into carbonizing device and reacted with ammonia. Nitrogen is removed form the obtained product. The obtained gas is refined, desulfurized and pressurized.    USE - Synthesis of ammonia.    ADVANTAGE - The method economically provides ammonia without environmental pollution.    DETAILED DESCRIPTION - Coke-oven gas is conveyed to a gas cabinet and pressurized by a Roots blower. The obtained product is passed through a temperature-variable absorption section for removing benzene and naphthalene. The material from which the benzene and naphthalene are removed is conveyed by the temperature-variable absorption method into a reciprocating compressor and pressurized at 0.8 MPa. Carbon monoxide in the compressed gas is converted into carbon dioxide and hydrogen through exchange reaction. Then, the conversion gas is desulfurized. The desulfurized conversion gas is divided into two portions, in which one portion directly enters a carbonizing device for carbonization and the other portion enter a pressure swing adsorption (PSA) decarbonizing device. The product analyzed by PSA decarbonizing device is pressurized at 0.8 MPa. The obtained product and conversion gas are supplied into carbonizing device and reacted with concentrated aqueous ammonia, to obtain ammonium bicarbonate fertilizer. The material gas not disposed in the PSA decarbonizing device and the carbonizing device is conveyed to the reciprocating compressor, compressed at 2.1 MPa and methane is removed by pressure-variable absorption method. Nitrogen is removed form the obtained gas by performing the pressure-variable absorption method. The ratio of hydrogen and nitrogen is adjusted to 3:1. The obtained gas is refined and desulfurized. Then, methanation treatment is performed to refine carbon monoxide and carbon dioxide in the gas. Then, the gas is pressurized at 3.14 MPa by synthesis gas compressor. The obtained synthesis gas is conveyed to ammonia synthesis process, to obtain ammonia.