Roger D Parrish

US Patent:

39475514, Mar 30, 1976

Filed:

May 29, 1974

Appl. No.:

5/474232

Inventors:

Roger W. Parrish - Pittsburgh PA

Assignee:

The Benfield Corporation - Berwyn PA

International Classification:

C01C 104

US Classification:

423359

Abstract:

An improved ammonia synthesis train utilizing hydrocarbon starting materials which are converted to hydrogen under superatmospheric pressure in a series of steps which include conversion of the hydrocarbons to hydrogen-carbon monoxide mixtures, shift conversion of the carbon monoxide to hydrogen and CO. sub. 2, and removal of the CO. sub. 2. In such a system, reduction in process gas losses is achieved through an improved arrangement and integration of the shift conversion and CO. sub. 2 removal steps. The carbon monoxide is first shifted in a series of shifts including a final low temperature shift; the bulk of the CO. sub. 2 is removed by an essentially isothermal hot potassium carbonate CO. sub. 2 removal system; the small residual amount of carbon monoxide is shifted to very low levels in a final low temperature shift; and the small amount of residual CO. sub. 2 is then removed to very low levels in a second non-isothermal scrubbing system employing an aqueous solution of a chemical absorbent.