Ammonia synthesis gas purification

Patent · Mon Feb 24 23:00:00 EST 1986

OSTI ID:5918529

Fuderer, A

This patent describes the purification of a reformed gas mixture following water gas shift conversion to produce a purified ammonia synthesis gas stream. The improved processing sequence consisting essentially of: (A) Selectively catalytically oxidizing the residual carbon monoxide content of the gas mixture to carbon dioxide so as to reduce the carbon monoxide content of the gas mixture to less than about 20 ppm, the selective catalytic oxidation being carried out with an excess of air, with the excess oxygen being catalytically reacted with a small amount of hydrogen so that the residual oxygen level is reduced to less than about 3 ppm; (B) removing the bulk of the carbon dioxide content of the gas mixture by liquid absorption; (C) Removing residual amounts of carbon monoxide, carbon dioxide and water by selective adsorption on the fixed beds of a thermal swing adsorption system, a dry, purified ammonia ammonia synthesis gas stream containing less than a total of 10 ppm of carbon monoxide and carbon dioxide being recovered from the thermal swing adsorption system; (D) Passing the resulting dry, purified ammonia synthesis gas stream having a low content of methane to an ammonia production operation without intermediate passage of the ammonia synthesis gas stream to a methanation unit or to a cryogenic unit for removal of carbon monoxide and carbon dioxide therefrom; whereby the efficiency of the overall purification operation and the effective utilization of hydrogen are enhanced.

• Assignee: Union Carbide Corp., Danbury, CT
• Patent Number(s): US 4572829
• OSTI ID: 5918529
• Country of Publication: United States
• Language: English

Related Subjects

090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
090320 -- Inorganic Hydrogen Compound Fuels-- Preparation-- (1976-1989)
10 SYNTHETIC FUELS
ABSORPTION
AIR
ALKANES
AMMONIA
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
ELEMENTS
FLUIDS
GASES
HYDRIDES
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
METHANATION
METHANE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PACKED BED
PURIFICATION
REDUCTION
SYNTHESIS
SYNTHESIS GAS
WATER GAS PROCESSES