Recovery of nitrogen, hydrogen and carbon dioxide from hydrocarbon reformate

Patent · Tue Mar 21 04:00:00 EST 1989

OSTI ID:6078490

Sircar, S

This patent describes a method of separately recovering high purity carbon dioxide and ammonia synthesis gas composed of hydrogen and nitrogen at near the 3:1 stoichiometric ratio, from a starting gas mixture containing hydrogen, carbon dioxide and nitrogen as bulk components and less than a total of 10 mol % on a dry basis of minor components which comprises: (a) passing the starting gas at super atmospheric pressure into and through a first bed of solid adsorbent wherein carbon dioxide is selectively adsorbed; discharging unadsorbed gas from the first bed into and through a second bed of adsorbent effective in retaining at least part of the minor components of the starting gas; and discharging from the second bed as primary effluent the unadsorbed portion of the gas passed therethrough; (b) rinsing the first bed with a stream of high purity carbon dioxide passed into the bed for a time short of complete breakthrough of a carbon dioxide front at the effluent end while discharging effluent gas therefrom and mixing the effluent gas with fresh starting feed gas; (c) desorbing carbon dioxide from the first bed by gas with drawal to near ambient pressure level; (d) lowering the pressure in the first bed by evacuation to subatmospheric level thereby obtaining an effluent rich in carbon dioxide; (e) partly repressurizing the evacuated first bed by flow of gas into the bed from a second bed which is at superatmospheric pressure levels, to bring the first and second beds to substantially equal pressure; and (f) further repressuring the first bed to superatmospheric pressure level to prepare the same for further adsorption of CO/sub 2/ from the starting gas.

• Assignee: Air Products and Chemicals, Inc., Allentown, PA
• Patent Number(s): US 4813980
• OSTI ID: 6078490
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030300* -- Natural Gas-- Drilling
Production
& Processing
AMMONIA
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DESORPTION
ELEMENTS
HYDRIDES
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
NITROGEN
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PRESSURIZING
PRODUCTION
RECOVERY
SEPARATION PROCESSES