GB734498A - Polymerisation of olefins - Google Patents

Abstract

Products of gasoline boiling range are obtained by polymerizing normally gaseous olefins in the vapour phase at 0-200, preferably 20-30 DEG C., in the presence of a complex of boron fluoride with a saturated organic compound containing at least two "active" oxygen atoms attached to different carbon atoms. "Active" oxygen atoms are those having one valency satisfied by a carbon atom and the other by an atom other than a second carbon atom. Thus, active oxygen groups are hydroxyl, carboxyl, and carbonyl. The carbon chain between the two active oxygens is desirably not more than four carbon atoms. Preferably the organic compound boils above 100 or 150 DEG C., and is liquid at normal temperatures or melts not greatly above 50, and preferably below about 60 DEG C. Examples of suitable compounds are polyhydric alcohols, polybasic acids or esters thereof, and hydroxy acids, e.g. ethylene glycol and its homologues, polyalkylene glycols, e.g. di- and tri-ethylene or propylene glycols, glycerol, glutaric and pimelic acids, methyl succinate, hydroxy-propionic and butyric acids and their homologues. The complex is generally prepared by adding boron fluoride in a molar ratio of 1-2 : 1 to the organic compound, at ordinary or slightly elevated temperature. The product is suitably adsorbed on a carrier, e.g. activated carbon or clay, fuller's earth, pumice, kieselguhr, silica or alumina gel. A preferred feed is cracked refinery gas. Pressure may be atmospheric, and is generally less than 10 atmos. The gas may be passed through a fixed bed of the catalyst on a carrier while supplementary complex or boron fluoride may be injected to maintain activity. Alternatively, a guard bed of absorbent may be provided on the outlet side of the catalyst chamber to absorb volatilized complex or boron fluoride. Direction of flow of the feed may then be reversed. In examples, a feed containing butenes, butanes, and propane is passed down through a bed of complex on activated carbon, the former containing BF3 and lactic acid or ethylene glycol, and reaction temperature being 20 DEG C., which may later be raised to 70 DEG , 90 DEG or 100 DEG C.ALSO:Catalysts for polymerizing normally gaseous olefins comprise a complex of boron fluoride with a saturated organic compound containing at least two "active" oxygen atoms attached to different carbon atoms. "Active" oxygen atoms are those having one valency satisfied by a carbon atom and the other by an atom other than a second carbon atom. Thus, active oxygen groups are hydroxyl, carboxyl, and carbonyl. The carbon chain between the two active oxygens is desirably not more than four carbon atoms. Preferably the organic compound boils above 100 DEG or 150 DEG C., and is liquid at normal temperatures or melts not greatly above 50, and preferably below about 60 DEG C. Examples of suitable compounds are polyhydric alcohols, polybasic acids or esters thereof, and hydroxy acids, e.g. ethylene glycol and its homologues, polyalkylene glycols, glycerol, glutaric and pimelic acids, methyl succinatel hydroxy-propionic and butyric acids and their homologues. The complex is generally prepared by adding boron fluoride in a molar ratio of 1-2 : 1 to the organic compound, at ordinary or slightly elevated temperature. The product is suitably adsorbed on a carrier, e.g. activated carbon or clay, fuller's earth, pumice, kieselguhr, silica or alumina gel. A preferred feed is cracked refinery gas. Pressure may be atmospheric and is generally less than 10 atoms. The gas may be passed through a fixed bed of the catalyst on a carrier while supplementary complex or boron fluoride may be injected to maintain activity. Alternatively, a guard bed of absorbent may be provided on the outlet side of the catalyst chamber to absorb volatilized complex or boron fluoride. Direction of flow of the feed may then be reversed. In examples, the complex contains BF3 and lactic acid or ethylene glycol and is supported on activated carbon.