Production of ammonia synthesis gas
AssigneeFoster Wheeler USA Corporation
InventorsGeoffrey F. Skinner, Wieslaw M. Kowal, Stephen D. Linton
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Abstract
A process for removal of excess nitrogen and carbon oxides from a raw synthesis gas used to make ammonia. The raw synthesis gas is divided into two portions. The first portion is methanated to remove carbon oxides and then cooled to condense part of its nitrogen content. The condensed nitrogen is fed to the top of a nitrogen wash column. The second portion of the raw synthesis gas is passed over an absorbent which removes carbon dioxide and water vapor. It is then cooled to condense excess nitrogen. The remaining gas is fed to the bottom of a nitrogen wash column where it is washed free of carbon monoxide by the nitrogen condensed from the methanated gas stream.
Claims16
A process for the production of gaseous feed for the synthesis of ammonia from a raw synthesis gas stream comprising hydrogen, nitrogen and carbon monoxide having a molar ratio of hydrogen:
- nitrogen of less than 3:1, said process comprising:
- (a) subjecting a first portion of said raw synthesis gas stream to methanation to convert carbon monoxide contained therein to methane;
- (b) cooling and partially condensing the product of step (a);
- (c) cooling and partially condensing a second portion of said raw synthesis gas stream;
- (d) washing uncondensed product from step (c) with condensate from step (b);
- and
- (e) recovering washed gas from step (d) and uncondensed gas from step (b) for use as said gaseous feed for ammonia synthesis.
Dependencies are inferred from the claim text.