Patent ID: 6098424
Filing Date: 2000-08-08
Classification: C01B,F25J,Y10S

Abstract:
Process for the combined production of carbon monoxide and an ammonia synthesis gas from a feed gas mixture (50) containing essentially hydrogen, carbon monoxide and other constituents including methane, characterized in that it comprises the steps consisting in:subjecting the feed gas mixture (50) at high pressure to partial condensation by passing through a heat exchanger (310:310C) then separation in a separator pot (320:320C), producing an impure hydrogen flow (321:321C) at the head, and a condensed fraction (322, 322C) rich in carbon monoxide at the base;purifying, cryogenically, the carbon monoxide from the said condensed fraction (322;322C) by separation under medium pressure in a first stripping column (330;330C) removing the dissolved hydrogen at the head, then by low-pressure distillation in a distillation column (340;340C) separating the methane at the base, from the base mixture (333;333C) resulting from the separation in the stripping column (330;330C);sending the hydrogen from the separator pot to a washing column without heating it to ambient temperature;purifying, cryogenically, the hydrogen from the impure hydrogen flow (321,321C) by washing with nitrogen in the washing column (350;350C) while drawing off a liquid fraction (351;351C) rich in carbon monoxide at the base of the said washing column (350;350C); andproducing an ammonia syntheses mixture (385;385C) by adding a nitrogen supplement (372;372C) taken from a high-pressure nitrogen stream (370;370C), and from the hydrogen flow (353;353C) produced at the head of the washing column (350;350C), the steps of partial condensation and washing with nitrogen being carried out in the same plant (300,300C).