Process and apparatus for the production of hydrogen and carbon dioxide

Abstract

For the separation of substantially pure carbon dioxide and a gas enriched in hydrogen, said gases being especially suitable for the production of urea via an intermediate ammonia synthetic and reaction with CO.sub.4 a system is provided of A. scrubbing a raw gas consisting essentially of carbon dioxide, hydrogen and hydrogen sulfide in a first scrubbing stage with a first fraction of partially loaded physical scrubbing agent, e.g., methanol, to obtain a partially scrubbed raw gas depleted in H.sub.2 S and a more loaded scrubbing agent; B. scrubbing said partially scrubbed raw gas in a second stage with physical scrubbing agent to obtain a further scrubbed raw gas enriched in hydrogen and said partially loaded physical scrubbing agent; C. subjecting said more loaded scrubbing agent to at least one (preferably two) pressure reducing stages to obtain a gaseous phase therefrom; D. subjecting a second fraction of said partially loaded scrubbing agent to at least one pressure-reducing stage to obtain reduced pressure liquid phase substantially free of hydrogen sulfide; and E. scrubbing said gaseous phase of step (c) with at least a fraction of liquid phase of step (d) to obtain a scrubbed substantially pure carbon dioxide and hydrogen sulfide.

Dependencies are inferred from the claim text.