METHOD OF PRODUCING NITROGEN-HYDROGEN MIXTURE FOR SYNTHESIS OF AMMONIA BY PARTIAL OXIDATION OF HYDROGEN WITH AIR Russian patent published in 2024 - IPC C01B3/02 

FIELD: various technological processes.

SUBSTANCE: invention relates to a method of producing a nitrogen-hydrogen mixture. Method involves supply of a compressed air stream obtained by successive air compression from the atmosphere in three stages of a centrifugal compressor into a mixer in which hydrogen and air are mixed at pressure of 2.5-3.2 MPa with volume concentration of hydrogen in an air-hydrogen mixture of 71-73%. Further, the gas mixture obtained in the mixer is fed into an oxidation reactor, in which partial combustion of hydrogen takes place at a pressure of about 2.5 MPa. Obtained hot process gas from the reactor is fed into a heat exchanger, in which water vapour is superheated at pressure of 10.0 MPa to temperature of 480 °C, while at the outlet of the heat exchanger, the temperature of the hot process gas is reduced to 890 °C. At this temperature, gas enters the tube space of the waste heat boiler, in the tube space of which a steam-water mixture is formed, which rises into the steam separator. Water and steam are separated in the steam separator, the water flow enters the descending collector, from which it is recirculated in three successive flows into the heat recovery boiler. At the same time chemically purified water is added to the second flow. Saturated steam with pressure of 10.0 MPa and temperature of 310 °C from the steam separator is supplied to the tube space of the superheater-heat exchanger and then to the steam turbine, which drives the three-stage centrifugal compressor, wherein the steam output flow from the steam turbine has pressure of 0.6 MPa and temperature of 175 °C. Process gas flow from heat recovery boiler with temperature of 320°C and pressure of 2.3 MPa is sent to the reboiler of the ammonia desorption column, where it gives off heat to boiling water, while the temperature of the process gas stream is reduced to 240 °C. At this temperature, the process gas is fed into an air condenser-cooler, where it is cooled to 45 °C. Flow of cooled gas from condenser-cooler is supplied to separator of water condensate, from which flow of process gas is directed to booster compressor, and steam flow from output of steam turbine is supplied to condensation turbine, from which steam flow is supplied to air condenser-cooler. Water condensate formed in the condenser-cooler is pumped out to the water condensate separator, where it is combined with the condensate obtained from the process gas. Obtained condensate stream from the separator is fed for filtration and purification, after which it is returned to the steam generation system, wherein the excess water condensate is removed from the system, and the compressed process gas from the compressor outlet is directed to the adsorption dehydration unit to reduce moisture content to 5 mg/m³.

EFFECT: obtaining the target product with exclusion of the cryogenic air separation process, which leads to the most complete utilization of the heat of the exothermic oxidation reaction.

6 cl, 1 dwg