Absorption and conversion of acetylenic compounds

A method to remove acetylenic and diolefinic compounds from a monoolefinic stream and convert those acetylenic and diolefinic compounds into monoolefinic compounds comprising:

• contacting the monoolefin stream which contains acetylenic and diolefinic components with an aprotic, liquid solvent in which the acetylenic and diolefinic compounds are more soluble than the olefinic components thereby effecting at least some separation of the acetylenic and diolefinic compounds from the monoolefinic stream resulting in some concentration of the acetylenic and diolefinic compounds in the liquid solvent forming an enriched solvent and a lean monoolefin stream which is reduced in acetylenic and diolefinic compounds,
• introducing the enriched solvent to at least one reactor containing a supported catalyst which substantially retains or exceeds its initial activity and selectivity after 5 hours of operation wherein the supported catalyst comprises about 0.5% by weight palladium, gallium, and from about 0.05% to about 0.35% by weight zinc,
• co-currently introducing a stream comprising hydrogen and a stream comprising carbon monoxide to the at least one reactor,
• operating the at least one reactor at conditions sufficient to maintain a portion of the acetylenic and/or diolefinic compounds within the liquid phase and to hydrogenate at least a portion of the acetylenic and diolefinic compounds contained within the enriched absorbent to hydrogenation product monoolefins,
• recovering from the at least one reactor an outlet stream comprising the hydrogenation product monoolefins, hydrogen, carbon monoxide, and solvent, and
• separating a monoolefin product stream comprising the hydrogenation product monoolefins, hydrogen and carbon monoxide from the solvent to produce a lean solvent stream.

A method to remove contaminants selected from acetylenic and diolefinic compounds from a gaseous feedstream comprising monoolefins and convert at least some of those contaminants into monoolefinic compounds, the method comprising:

• (a) contacting the gaseous feedstream with an aprotic, liquid solvent in which the contaminants are more soluble than the monoolefins to form a first enriched solvent and a lean monoolefin gas stream, wherein the first enriched solvent comprises aprotic, liquid solvent and at least some of the contaminants and wherein the lean monoolefin gas stream is reduced in contaminants relative to the gaseous feedstream,
• (b) partitioning the first enriched solvent into a light gas phase stream and a heavy solvent stream, wherein the light gas phase stream comprises relatively lighter contaminants than the contaminants in the heavy solvent phase,
• (c) absorbing the light gas phase stream into lean aprotic, liquid solvent to form a second enriched solvent,
• (d) co-currently introducing the second enriched solvent and a gas stream comprising hydrogen or co-currently introducing the second enriched solvent, a gas stream comprising hydrogen and another gas stream comprising carbon monoxide into a first hydrogenation reactor containing a supported catalyst comprising a Group VIII element and operating the first hydrogenation reactor at conditions sufficient to maintain a portion of the contaminants therein within the liquid phase and to hydrogenate at least a portion of the contaminants contained within the second enriched solvent to light monoolefins, producing a first hydrogenation reactor product comprising light monoolefins and solvent,
• (e) separating the light monoolefins from the solvent, providing a first recovered solvent,
• (f) co-currently introducing the heavy solvent stream and a gas stream comprising hydrogen or co-currently introducing the heavy solvent stream, a gas stream comprising hydrogen and another gas stream comprising carbon monoxide into a second hydrogenation reactor containing a supported catalyst comprising a Group VIII element and operating the second hydrogenation reactor at conditions sufficient to maintain a portion of the contaminants therein within the liquid phase and to hydrogenate at least a portion of the contaminants contained within the heavy solvent stream to heavy monoolefins, and
• (g) separating the heavy monoolefins from the solvent, providing a second recovered solvent.