GB657014A - Gas separation in hydrocarbon synthesis - Google Patents

Abstract

In a process for producing a gas containing carbon monoxide and hydrogen in synthesis proportions in a synthesis gas generation zone and reacting the same in a catalytic synthesis zone, the reaction product is scrubbed with a solvent for carbon dioxide, and the solution stripped with a gas consisting of one or more of the components used in the feed for either the synthesis zone or the gas generation zone, at least part of the stripping gas containing stripped carbon dioxide being passed to said synthesis zone or gas generation zone. Natural gas may be oxidized with oxygen or a metal oxide and the product passed to a stripping tower down which carbon dioxide-rich liquid, e.g. triethanolamine, flows. The pressure preferably approximates that in the synthesis reactor. The enriched synthesis gas passes to a synthesis reactor containing fluidized iron or cobalt catalyst. The product is separated into gases and liquids, tail gas being scrubbed with carbon dioxide absorbent and, if desired, recycled. The enriched absorbent is circulated to the stripper. Alternatively, natural gas may be passed into the stripper and the effuent gas passed to a reformer where conversion with steam to carbon monoxide and hydrogen occurs. The gases pass to a synthesizer, tail gas being treated with absorbent solution which is then passed to the stripper. Flue gas from the reformer may be scrubbed with the absorbent solution and the solution passed to the same stripper. The evolved CO2 passes to the reformer. The stripping gas or solution to be stripped may be preheated, for example with flue p gas.