Process for recycling and purifying condensate from a hydrocarbon or alcohol synthesis process

Abstract

This invention relates to a process of recycling condensate from a hydrocarbon or alcohol synthesis, wherein the condensate comprises water and contaminants such as lower molecular weight hydrocarbons, alcohols, and other oxygenates. A hot gaseous mixture comprising CH4 and steam contacts the condensate so as to strip the contaminants from the condensate. The stripped contaminants, CH4, and steam are separately recovered as a gaseous stream from the remaining purified water. The recovered CH4-containing gaseous stream may be used in synthesis gas (CO / H2) generation processes with the generated synthesis gas then being used in a hydrocarbon synthesis process to produce heavy hydrocarbons.

Description

FIELD OF INVENTIONThis invention relates to a process of recycling condensate from a hydrocarbon or alcohol synthesis, wherein the condensate comprises water and orgaic compounds such as oxygenates, alcohols, and hydrocarbons, which comprises contacting the condensate with a hot gaseous mixture, preferably comprising CH.sub.4 and steam, to strip organic compounds and steam from the condensate; recovering a gaseous stream comprising the organic compounds; and separately recovering the purified liquid water of the condensate.BACKGROUND OF THE INVENTION AND PRIOR ARTCarbon monoxide and hydrogen may be reacted over a suitable catalyst to produce hydrocarbons and oxygenated compounds (such as aldehydes and alcohols) containing one or more carbon atoms. Perhaps the best known of such processes is the Fischer-Tropsch process which involves the catalytic hydrogenation of carbon monoxide to produce a variety of products ranging in size and functionality from methane to higher alcohols. The m...

AI Technical Summary

Benefits of technology

The present invention is directed at the purification of a typical condensate stream from a hydrocarbon synthesis or alcohol synthesis process. The condensate typically comprises water and contaminants, such as lower molecular weight hydrocarbons (after the desired heavier hydrocarbons have been separated), alcohols, and other oxygenates; water being the predominate component. The condensate is contacted with a hot gaseous mixture comprsing a light hydrocabon gas, preferably comprising CH.sub.4, and steam. The hot gaseous mixture strips the contaminants from the condensate leaving a stream of purified, clean water. The purified water has had about 80-90% of the contaminants removed. One advantage to this invention is that it provides an easy and cost saving process for purifying the condensate from synthesis processes without the need for expensive water treatment facilities.

Problems solved by technology

The separation is not necessarily complete, though, and often the condensate will have present in it some of the lower molecular weight hydrocarbons and oxygenates in the liquid phase.

This contaminated condensate is of little or no commercial value The oxygenates are known to cause corrosion while the hydrocarbons may cause foaming.

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