An extractive distillation column system contains a combination column and a side rectification column. A process can be used for separation of butenes from C4-hydrocarbon streams using the extractive distillation column system.

Provided is a method for preparing 1-butene and propylene including: supplying a C4 mixture stream to a first hydrogenation reactor to convert 1,3-butadiene into 1-butene; supplying a discharge stream from the first hydrogenation reactor to a first distillation column, supplying a lower discharge stream from the first distillation column including 2-butene and n-butane to a metathesis reactor, and supplying an upper discharge stream from the first distillation column including 1-butene and i-butane to a second distillation column; recovering an upper discharge stream the second distillation column including i-butane and recovering 1-butene from a lower discharge stream from the second distillation column; and producing propylene in the metathesis reactor, supplying a discharge stream from the metathesis reactor to a purification unit to recover propylene, and recycling an unreacted material to the metathesis reactor.

Provided is a method for preparing 1-butene and propylene including: supplying a C4 mixture stream to a first hydrogenation reactor to convert 1,3-butadiene into 1-butene; supplying a discharge stream from the first hydrogenation reactor to a first distillation column, supplying a lower discharge stream from the first distillation column including 2-butene and n-butane to a metathesis reactor, and supplying an upper discharge stream from the first distillation column including 1-butene and i-butane to a second distillation column; recovering an upper discharge stream the second distillation column including i-butane and recovering 1-butene from a lower discharge stream from the second distillation column; and producing propylene in the metathesis reactor, supplying a discharge stream from the metathesis reactor to a purification unit to recover propylene, and recycling an unreacted material to the metathesis reactor.

A method for producing a blended jet boiling range composition stream may include: oligomerizing an ethylene stream to a C4+ olefin stream in a first olefin oligomerization unit, wherein the C4+ olefin stream contains no greater than 10 wt % of methane, ethylene, and ethane combined; wherein the ethylene stream contains at least 50 wt % ethylene, at least 2000 wppm ethane, no greater than 1000 wppm of methane, and no greater than 20 wppm each of carbon monoxide and hydrogen; oligomerizing the C4+ olefin stream and a propylene/C4+ olefin stream in a second oligomerization unit to produce an isoolefinic stream; subjecting at least a portion of the isoolefinic stream to a hydroprocessing process with hydrogen as treat gas to produce an isoparaffinic stream having no greater than 10 wt % olefin content; and using least a portion of the isoparaffinic stream to create the blended jet boiling range.

A method for producing a blended jet boiling range composition stream may include: oligomerizing an ethylene stream to a C4+ olefin stream in a first olefin oligomerization unit, wherein the C4+ olefin stream contains no greater than 10 wt % of methane, ethylene, and ethane combined; wherein the ethylene stream contains at least 50 wt % ethylene, at least 2000 wppm ethane, no greater than 1000 wppm of methane, and no greater than 20 wppm each of carbon monoxide and hydrogen; oligomerizing the C4+ olefin stream and a propylene/C4+ olefin stream in a second oligomerization unit to produce an isoolefinic stream; subjecting at least a portion of the isoolefinic stream to a hydroprocessing process with hydrogen as treat gas to produce an isoparaffinic stream having no greater than 10 wt % olefin content; and using least a portion of the isoparaffinic stream to create the blended jet boiling range.

A method for producing a blended jet boiling range composition stream may include: oligomerizing an ethylene stream to a C4+ olefin stream in a first olefin oligomerization unit, wherein the C4+ olefin stream contains no greater than 10 wt % of methane, ethylene, and ethane combined; wherein the ethylene stream contains at least 50 wt % ethylene, at least 2000 wppm ethane, no greater than 1000 wppm of methane, and no greater than 20 wppm each of carbon monoxide and hydrogen; oligomerizing the C4+ olefin stream and a propylene/C4+ olefin stream in a second oligomerization unit to produce an isoolefinic stream; subjecting at least a portion of the isoolefinic stream to a hydroprocessing process with hydrogen as treat gas to produce an isoparaffinic stream having no greater than 10 wt % olefin content; and using least a portion of the isoparaffinic stream to create the blended jet boiling range.

The invention relates to a hydrogel product comprising glycosaminoglycan molecules as the swellable polymer, wherein the glycosaminoglycan molecules are covalently crosslinked via crosslinks comprising a spacer group selected from the group consisting of di-, tri-, tetra-, and oligosaccharides.

A system and a method for separating C.sub.4 and recovering 1,3-butadiene are disclosed. The system includes a main washer column, a rectifier column for separating a bottom stream from the main washer column, an after washer column for purifying 1,3-butadiene from a side stream of the rectifier column comprising acetylenes and butadienes, a degasser column for separating a bottom stream from the rectifier column to produce a lean solvent stream. The lean solvent stream comprises primarily the solvent and about 8.3% water used in the main washer column and after washer column. A reboiler for the rectifier column includes one or more heat exchange units. At least one of the heat exchange units of the reboiler for the rectifier column uses steam as heating medium.

A system and a method for separating C.sub.4 and recovering 1,3-butadiene are disclosed. The system includes a main washer column, a rectifier column for separating a bottom stream from the main washer column, an after washer column for purifying 1,3-butadiene from a side stream of the rectifier column comprising acetylenes and butadienes, a degasser column for separating a bottom stream from the rectifier column to produce a lean solvent stream. The lean solvent stream comprises primarily the solvent and about 8.3% water used in the main washer column and after washer column. A reboiler for the rectifier column includes one or more heat exchange units. At least one of the heat exchange units of the reboiler for the rectifier column uses steam as heating medium.

A system and a method for separating C.sub.4 and recovering 1,3-butadiene are disclosed. The system includes a main washer column, a rectifier column for separating a bottom stream from the main washer column, an after washer column for purifying 1,3-butadiene from a side stream of the rectifier column comprising acetylenes and butadienes, a degasser column for separating a bottom stream from the rectifier column to produce a lean solvent stream. The lean solvent stream comprises primarily the solvent and about 8.3% water used in the main washer column and after washer column. A reboiler for the rectifier column includes one or more heat exchange units. At least one of the heat exchange units of the reboiler for the rectifier column uses steam as heating medium.