WO2022132865A1 - A process for producing alpha-olefins - Google Patents

A process for producing alpha-olefins Download PDF

Info

Publication number
WO2022132865A1
WO2022132865A1 PCT/US2021/063455 US2021063455W WO2022132865A1 WO 2022132865 A1 WO2022132865 A1 WO 2022132865A1 US 2021063455 W US2021063455 W US 2021063455W WO 2022132865 A1 WO2022132865 A1 WO 2022132865A1
Authority
WO
WIPO (PCT)
Prior art keywords
catalyst
oligomerization
olefins
ligand
alpha
Prior art date
Application number
PCT/US2021/063455
Other languages
French (fr)
Inventor
Cornelius Mark Bolinger
Hilario Rivera GARZA
Brent Carl NORRIS
Christopher Stephen GILL
Robert Stephen Tomaskovic
Original Assignee
Shell Oil Company
Shell Internationale Research Maatschappij Bv
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shell Oil Company, Shell Internationale Research Maatschappij Bv filed Critical Shell Oil Company
Publication of WO2022132865A1 publication Critical patent/WO2022132865A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G50/00—Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
    • C07C2/02—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons
    • C07C2/04—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation
    • C07C2/06—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation of alkenes, i.e. acyclic hydrocarbons having only one carbon-to-carbon double bond
    • C07C2/08—Catalytic processes
    • C07C2/26—Catalytic processes with hydrides or organic compounds
    • C07C2/32—Catalytic processes with hydrides or organic compounds as complexes, e.g. acetyl-acetonates
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
    • C07C2/02—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons
    • C07C2/04—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation
    • C07C2/06—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation of alkenes, i.e. acyclic hydrocarbons having only one carbon-to-carbon double bond
    • C07C2/08—Catalytic processes
    • C07C2/26—Catalytic processes with hydrides or organic compounds
    • C07C2/32—Catalytic processes with hydrides or organic compounds as complexes, e.g. acetyl-acetonates
    • C07C2/34—Metal-hydrocarbon complexes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2531/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • C07C2531/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • C07C2531/12—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing organo-metallic compounds or metal hydrides
    • C07C2531/14—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing organo-metallic compounds or metal hydrides of aluminium or boron
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2531/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • C07C2531/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
    • C07C2531/22—Organic complexes
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
    • C10G2400/22—Higher olefins
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/582—Recycling of unreacted starting or intermediate materials

Definitions

  • the invention relates to a process for producing alpha-olefins and using those alpha-olefins in a polymerization process.
  • Linear alpha olefins are a valuable comonomer for linear low-density polyethylene and high-density polyethylene.
  • Such olefins are also valuable as a chemical intermediate in the production of plasticizer alcohols, fatty acids, detergent alcohols, polyalphaolefins, oil field drilling fluids, lubricant oil additives, linear alkylbenzenes, alkenylsuccinic anhydrides, alkyldimethylamines, dialkylmethylamines, alpha-olefin sulfonates, internal olefin sulfonates, chlorinated olefins, linear mercaptans, aluminum alkyls, alkyldiphenylether disulfonates, and other chemicals.
  • US 6,683,187 describes a bis(arylimino)pyridine ligand, catalyst precursors and catalyst systems derived from this ligand for ethylene oligomerization to form linear alpha olefins.
  • the patent teaches the production of linear alpha olefins with a Schulz -Flory oligomerization product distribution. In such a process, a wide range of oligomers are produced, and the fraction of each olefin can be determined by calculation on the basis of the K-factor.
  • the K-factor is the molar ratio of (C n +2)/C n , where n is the number of carbons in the linear alpha olefin product.
  • the invention provides a process for producing alpha-olefins comprising contacting an ethylene feed with an oligomerization catalyst system in an oligomerization reaction zone under oligomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises a metal-ligand complex and a co-catalyst and the oEgomerization conditions are selected such that the product stream contains less than 10 ppmw of 1,3-hexadiene.
  • the invention further provides a process for producing polyethylene comprising contacting ethylene with one or more alpha olefins in the presence of a polymerization catalyst wherein the one or more alpha olefins are produced in a process comprising contacting an ethylene feed with an oEgomerization catalyst system in an oEgomerization reaction zone under oEgomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises an iron-pyridine bisimine complex and an MMAO co-catalyst and the oEgomerization conditions are selected such that the one or more alpha-olefins contain less than 100 ppmw of 1,3-hexadiene.
  • the process comprises converting an olefin feed into a higher oligomer product stream by contacting the feed with an oEgomerization catalyst system and a co-catalyst in an oEgomerization reaction zone under oEgomerization conditions.
  • an ethylene feed may be contacted with an iron-Egand complex and modified methyl aluminoxane under oEgomerization conditions to produce a product slate of alpha olefins having a specific k-factor.
  • the olefin feed to the process comprises ethylene.
  • the feed may also comprise olefins having from 3 to 8 carbon atoms.
  • the ethylene may be pretreated to remove impurities, especially impurities that impact the reaction, product quaEty or damage the catalyst.
  • the ethylene may be dried to remove water.
  • the ethylene may be treated to reduce the oxygen content of the ethylene. Any pretreatment method known to one of ordinary skill in the art can be used to pretreat the feed.
  • the oEgomerization catalyst system may comprise one or more oEgomerization catalysts as described further herein.
  • the oEgomerization catalyst is a metal-ligand complex that is effective for catalyzing an oEgomerization process.
  • the ligand may comprise a bis(aryEmino)pyridine compound, a bis(alkylimino)pyridine compound or a mixed aryl-alkyl iminopyridine compound.
  • the Egand comprises a pyridine bis(imine) group.
  • the Egand may be a bis(arylimino)pyridine compound having the structure of Formula I.
  • R 1 , R 2 and R 3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 4 and R 5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 6 and R 7 are each independently an aryl group as shown in Formula II. The two aryl groups ( R 6 and R 7 ) on one Egand may be the same or different.
  • R 8 , R 9 , R 10 , R 11 , R 12 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R 1 -R 3 , and R 9 - R 11 vicinal to one another taken together may form a ring. R 12 may be taken together with R 11 , R 4 or R 5 to form a ring. R 2 and R 4 or R 3 and R 5 may be taken together to form a ring.
  • a hydrocarbyl group is a group containing only carbon and hydrogen. The number of carbon atoms in this group is preferably in the range of from 1 to 30.
  • An optionally substituted hydrocarbyl is a hydrocarbyl group that optionally contains one or more “inert” heteroatom-containing functional groups.
  • Inert means that the functional groups do not interfere to any substantial degree with the oligomerization process. Examples of these inert groups include fluoride, chloride, iodide, stannanes, ethers, hydroxides, alkoxides and amines with adequate steric shielding.
  • the optionally substituted hydrocarbyl group may include primary, secondary and tertiary carbon atoms groups.
  • Primary carbon atom groups are a -CH 2 -R group wherein R may be hydrogen, an optionally substituted hydrocarbyl or an inert functional group.
  • Examples of primary carbon atom groups include -CH 3 , -C 2 H 5 , -CH 2 CI, -CH 2 OCH 3 , -CH 2 N( C 2 H 5 and -CE 2 Ph.
  • Secondary carbon atom groups are a -CH-R 2 or -CH (R)(R') group wherein R and R' may be optionally substituted hydrocarbyl or an inert functional group.
  • Tertiary carbon atom groups are a -C-(R)(R')(R") group wherein R, R', and R" may be optionally substituted hydrocarbyl or an inert functional group.
  • Examples of tertiary carbon atom groups include -C(CH 3 ) 3 , -CC1 3 , - C ⁇ CPh, 1-Adamantyl, and -C(CH 3 ) 2 (OCH 3 )
  • An inert functional group is a group other than optionally substituted hydrocarbyl that is inert under the oligomerization conditions. Inert has the same meaning as provided above. Examples of inert functional groups include halide, ethers, and amines, in particular tertiary amines.
  • R 1 -R 5 , R 8 -R 12 and R 13 -R 17 may be selected to enhance other properties of the ligand, for example, solubility in non-polar solvents.
  • R 8 -R 12 and R 13 -R 17 may be selected to enhance other properties of the ligand, for example, solubility in non-polar solvents.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 11 and R 14 -R 16 are hydrogen; and R 8 , R 12 , R 13 and R 17 are fluorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 10 , R 12 , R 14 andR 16 ate hydrogen; R 13 , R 15 and R 17 are methyl and R 9 and R 11 are tert-butyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 12 , R 14 and R 16 are hydrogen; R 13 , R 15 and R 17 are methyl; R 9 and R 11 are phenyl and R 10 is an alkoxy.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 10 , R 11 and R 14 - R 16 are hydrogen; R 9 and R 12 are methyl; and R 13 and R 17 are fluorine.
  • a ligand of Formula III wherein R 1 -R 3 , R 9 -R 11 and R 14 -R 16 are hydrogen; R 4 and R 5 are phenyl and R 8 , R 12 , R 13 and R 17 are fluorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 - R 9 , R 11 -R 12 , R 13 - R 14 and R 16 -R 17 are hydrogen; and R 10 and R 15 are fluorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 10 , R 12 , R 13 , R 15 and R 17 are hydrogen; and R 9 , R 11 , R 14 and R 16 are fluorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 ,R 11 -R 12 , R 14 and R 16 -R 17 are hydrogen; and R 8 , R 10 , R 13 and R 15 are fluorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 - R 9 .
  • R 11 - R 12 , R 14 and R 16 are hydrogen;
  • R 10 is tert-butyl;
  • R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 9 -R 12 , R 14 and R 16 are hydrogen;
  • R 8 is fluorine; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 12 , R 13 , R 15 and R 17 are hydrogen; R 8 is tert-butyl; and R 14 and R 16 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 12 , R 13 -R 14 and R 16 -R 17 are hydrogen; and R 8 and R 15 are tert-butyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 -R 10 , R 13 -R 14 and R 16 -R 17 are hydrogen; R 15 is tert-butyl; and R 11 and R 12 are taken together to form an aryl group.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 9 -R 12 , R 14 -R 17 are hydrogen; and R 8 and R 13 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 -R 9 .R 11 -R 12 , R 14 and R 16 are hydrogen; R 10 is fluorine; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 10 , R 12 , R 14 and R 16 are hydrogen; R 9 and R 11 are fluorine; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 -R 9 ,R 11 -R 12 , R 14 and R 16 are hydrogen; R 10 is an alkoxy; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 -R 9 .R 11 -Ru, R 14 and R 16 are hydrogen; R 10 is a silyl ether; and R 13 , R 15 and Ru are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 10 , R 12 , R 14 -R 16 are hydrogen; R 9 and R 11 are methyl; and R 13 and R 17 are ethyl.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 9 -R 12 , and R 14 -R 17 are hydrogen; and R 8 and R 13 are ethyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 11 and R 14 -R 16 are hydrogen; and R 8 , R 12 , R 13 and R 17 are chlorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 , R 11 , R 14 and R 16 are hydrogen; and R 8 , R 10 , R 12 , R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R10, R 12 , R 14 -R 15 and R 17 are hydrogen; and R 8 , R 11 , R 13 and R 16 are methyl.
  • a ligand of Formula III is provided wherein R 1 -R 17 are hydrogen.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 8 , R 10 , R 12 , R 13 , R 15 and R 17 are hydrogen; and R 9 , Ru, R 14 and R 16 are tert-butyl.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 8 -R 12 , R 14 and R 16 are hydrogen; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 , R 11 -R 12 , R 14 and R 16 are hydrogen; R 8 and R 10 are fluorine; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 9 , R 11 -R 12 , R 14 and R 16 -R 17 are hydrogen; and R 8 , R 10 , R 13 and R 15 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 11 and R 14 -R 16 are hydrogen; R 8 and R 12 are chlorine; and R 13 and R 17 are fluorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 , R 10 , R 12 , R 14 andR 16 are hydrogen; and R 9 , R 11 , R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 11 and R 13 -R 14 and R 16 -R 17 are hydrogen; R 8 and R 12 are chlorine; and R 15 is tert-butyl.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 9 -R 11 and R 13 -R 17 are hydrogen; and R 8 and R 12 are chlorine.
  • a ligand of Formula III is provided wherein R 1 -R 5 , R 9 -R 12 , and R 14 -R 17 are hydrogen; and R 8 and R 13 are chlorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 ,R 11 -R 12 , R 14 and R 16 -R 17 are hydrogen; and R 8 , R 10 , R 13 and R 15 are chlorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 , R 11 -R 12 , and R 14 , and R 16 - R 17 are hydrogen; R 10 and R 15 are methyl; and R 8 and R 13 are chlorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 11 and R 13 -R 14 and R 16 - R 17 are hydrogen; R 15 is fluorine; and R 8 and R 12 are chlorine.
  • a ligand of Formula III wherein R 1 -R 5 , R 8 -R 9 , R 11 -R 12 , R 14 - R 15 and R 17 are hydrogen; R 10 is tert-butyl; and R 13 and R 16 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 11 , R 14 and R 16 are hydrogen; R 8 and R 12 are fluorine; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R10, R 12 , R 14 -R 15 and R 17 are hydrogen; R 8 and R 13 are methyl; and R 11 and R 16 , are isopropyl.
  • a ligand of Formula III wherein R 1 -R 5 , R 9 -R 12 and R 14 - R 16 are hydrogen; R 8 is ethyl; and R 13 and R 17 are fluorine.
  • a ligand of Formula III wherein R 2 -R 5 , R 9 -R10, R 12 , R 14 -R 15 and R 17 are hydrogen; R 1 is methoxy; and R 8 , R 11 , R 13 and R 16 are methyl.
  • a ligand of Formula III is provided wherein R 2 -R 5 , R 8 -R 12 , R 14 and R 16 are hydrogen; R 1 is methoxy; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 2 -R 5 , R 9 -R 12 , and R 14 -R 17 are hydrogen; R 1 is methoxy; and R 8 and R 13 are ethyl.
  • a ligand of Formula III wherein R 2 -R 5 , R 9 , R 11 -R 12 , R 14 and R 16 -R 17 are hydrogen; R 1 is tert-butyl; and R 8 , R 10 , R 13 and R 15 are methyl.
  • a ligand of Formula III wherein R 2 -R 5 , R 8 -R 12 , R 14 and R 16 are hydrogen; R 1 is tert-butyl; and R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 2 -R 5 , R 9 , R 11 , R 14 and R 16 are hydrogen; R 1 is methoxy; and R 8 , R 10 , R 12 , R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 2 -R 5 , R 9 , R 11 , R 14 and R 16 are hydrogen; R 1 is alkoxy; and R 8 , R 10 , R 12 , R 13 , R 15 and R 17 are methyl.
  • a ligand of Formula III wherein R 2 -R 5 , R 9 , R 11 , R 14 and R 16 are hydrogen; R 1 is tert-butyl; and R 8 , R 10 , R 12 , R 13 , R 15 and R 17 are methyl.
  • the ligand may be a compound having the structure of Formula I, wherein one of R 6 and R 7 is aryl as shown in Formula II and one of R 6 and R 7 is pyridyl as shown in Formula IV.
  • R 6 and R 7 may be pyrrolyl.
  • R 1 , R 2 and R 3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 4 and R 5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 8 -R 12 and R 18 -R 21 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R 1 -R 3 , and R 9 -R 11 vicinal to one another taken together may form a ring.
  • R 12 may be taken together with R 11 , R 4 or R 5 to form a ring.
  • R 2 and R 4 or R 3 and R 5 may be taken together to form a ring.
  • a ligand of Formula V is provided wherein R 1 -R 5 , R 9 , R 11 and R 18 -R 21 are hydrogen; and R 8 , R 10 , and R 12 are methyl.
  • a ligand of Formula V is provided wherein R 1 -R 5 , R 9 -R 11 and R 18 -R 21 are hydrogen; and R 8 and R 12 are ethyl.
  • the ligand may be a compound having the structure of Formula I, wherein one of R 6 and R 7 is aryl as shown in Formula II and one of R 8 and R 7 is cyclohexyl as shown in Formula VI. In another embodiment, R 6 and R 7 may be cyclohexyl.
  • R 1 , R 2 and R 3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 4 and R 5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 8 -R 12 and R 22 -R 26 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R 1 -R 3 , and R 9 -R 11 vicinal to one another taken together may form a ring.
  • R 12 may be taken together with R 11 , R 4 or R 5 to form a ring.
  • R 2 and R 4 or R 3 and R 5 may
  • a ligand of Formula VII is provided wherein R 1 -R 5 , R 9 , R 11 and R 22 -R 26 are hydrogen; and R 8 , R 10 , and R 12 are methyl.
  • R 6 and R 7 may be adamantyl or another cycloalkane.
  • the ligand may be a compound having the structure of Formula I, wherein one of R 6 and R 7 is aryl as shown in Formula II and one of R 6 and R 7 is ferrocenyl as shown in Formula VIII. In another embodiment, R 6 and R 7 may be ferrocenyl.
  • R 1 , R 2 and R 3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 4 and R 5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group.
  • R 8 - R 12 and R 2 7 -R 35 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R 1 -R 3 , and R 9 -R 11 vicinal to one another taken together may form a ring.
  • R 12 may be taken together with R 11 , R 4 or R 5 to form a ring.
  • R 2 and R 4 or R 3 and R 5 may be taken together to form a ring.
  • a ligand of Formula IX is provided wherein R 1 -R 5 , R 9 , R 11 and R 2 7 -R 35 are hydrogen; and R 8 , R 10 , and R 12 are methyl.
  • a ligand of Formula IX is provided wherein R 1 -R 5 , R 9 -R 11 , and R 27 -R 35 are hydrogen; and R 8 and R 12 are ethyl.
  • the ligand may be a bis(alkylamino)pyridine.
  • the alkyl group may have from 1 to 50 carbon atoms.
  • the alkyl group may be a primary, secondary, or tertiary alkyl group.
  • the alkyl group may be selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, and tert-butyl.
  • the alkyl group may be selected from any n-alkyl or structural isomer of an n-alkyl having 5 or more carbon atoms, e.g., n-pentyl; 2-methyl-butyl; and 2,2-dimethylpropyl.
  • the ligand may be an alkyl-alkyl iminopyridine, where the two alkyl groups are different. Any of the alkyl groups described above as being suitable for a bis(alkylamino)pyridine are also suitable for this alkyl-alkyl iminopyridine.
  • the ligand may be an aryl alkyl iminopyridine.
  • the aryl group may be of a similar nature to any of the aryl groups described with respect to the bis(arylimino)pyridine compound and the alkyl group may be of a similar nature to any of the alkyl groups described with respect to the bis(alkylamino)pyridine compound.
  • any structure that combines features of any two or more of these ligands can be a suitable ligand for this process.
  • the oligomerization catalyst system may comprise a combination of one or more of any of the described oligomerizations catalysts.
  • the ligand feedstock may contain between 0 and 10 wt.% bisimine pyridine impurity, preferably 0-1 wt.% bisimine pyridine impurity, most preferably 0-0.1 wt.% bisimine pyridine impurity. This impurity is believed to cause the formation of polymers in the reactor, so it is preferable to limit the amount of this impurity that is present in the catalyst system.
  • the bisimine pyridine impurity is a ligand of Formula II in which three of R 8 , R 12 , R 13 , and R 17 are each independently optionally substituted hydrocarbyl.
  • the bisimine pyridine impurity is a ligand of Formula II in which all four of R 8 , R 12 , R 13 , and R 17 are each independently optionally substituted hydrocarbyl.
  • the metal may be a transition metal, and the metal is preferably present as a compound having the formula MX n , where M is the metal, X is a monoanion and n represents the number of monoanions (and the oxidation state of the metal).
  • the metal can comprise any Group 4-10 transition metal.
  • the metal can be selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, palladium, platinum, ruthenium and rhodium.
  • the metal is cobalt or iron.
  • the metal is iron.
  • the metal of the metal compound can have any positive formal oxidation state of from 2 to 6 and is preferably 2 or 3.
  • the monoanion may comprise a halide, a carboxylate, a ⁇ -diketonate, a hydrocarboxide, an optionally substituted hydrocarbyl, an amide or a hydride.
  • the hydrocarboxide may be an alkoxide, an aryloxide or an aralkoxide.
  • the halide may be fluorine, chlorine, bromine or iodine.
  • the carboxylate may be any C 1 to C 20 carboxylate.
  • the carboxylate may be acetate, a propionate, a butyrate, a pentanoate, a hexanoate, a heptanoate, an octanoate, a nonanoate, a decanoate, an undecanoate, or a dodecanoate.
  • the carboxylate may be 2-ethylhexanoate or trifluoroacetate.
  • the ⁇ -diketonate may be any C 1 to C 20 [3-diketonate.
  • the ⁇ -diketonate may be acetylacetonate, hexafluoroacetylacetonate, or benzoylacetonate.
  • the hydrocarboxide may be any C 1 to C 20 hydrocarboxide.
  • the hydrocarboxide may be a Ci to C 20 alkoxide, or a C 6 to C 20 aryloxide.
  • the alkoxide may be methoxide, ethoxide, a propoxide (e.g., iso-propoxide) or a butoxide (e.g., tert-butoxide).
  • the aryloxide may be phenoxide
  • the number of monoanions equals the formal oxidation state of the metal atom.
  • metal compounds include iron acetylacetonate, iron chloride, and iron bis(2-ethylhexanoate).
  • a co-catalyst is used in the oligomerization reaction.
  • the co-catalyst may be a compound that is capable of transferring an optionally substituted hydrocarbyl or hydride group to the metal atom of the catalyst and is also capable of abstracting an X' group from the metal atom M.
  • the co-catalyst may also be capable of serving as an electron transfer reagent or providing sterically hindered counterions for an active catalyst.
  • the co-catalyst may comprise two compounds, for example one compound that is capable of transferring an optionally substituted hydrocarbyl or hydride group to metal atom M and another compound that is capable of abstracting an X group from metal atom M.
  • Suitable compounds for transferring an optionally substituted hydrocarbyl or hydride group to metal atom M include organoaluminum compounds, alkyl lithium compounds, Grignards, alkyl tin and alkyl zinc compounds.
  • Suitable compounds for abstracting an X group from metal atom M include strong neutral Lewis acids such as SbF 5 , BF 3 and Ar 3 B wherein Ar is a strong electron-withdrawing aryl group such as C 6 F 5 or 3,5-(CF 3 ) 2 C 6 H 3 .
  • a neutral Lewis acid donor molecule is a compound which may suitably act as a Lewis base, such as ethers, amines, sulfides and organic nitrites.
  • the co-catalyst is preferably an organoaluminum compound which may comprise an alkylaluminum compound, an aluminoxane or a combination thereof.
  • the alkylaluminum compound may be trialkylaluminum, an alkylaluminum halide, an alkylaluminum alkoxide or a combination thereof.
  • the alkyl group of the alkylaluminum compound may be any C 1 to C 20 alkyl group.
  • the alkyl group may be methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl.
  • the alkyl group may be an iso-alkyl group.
  • the trialkylaluminum compound may comprise trimcthylaluminum (TMA), triethylaluminum (TEA), triptopylaluminum, tributylaluminum, tripentylaluminum, trihexylaluminum, triheptylaluminum, trioctylaluminum or mixtures thereof.
  • the trialkylaluminum compound may comprise tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA), tri-iso- butylaluminum (TIB A), tri-n-hexylaluminum, tri-n-octylaluminum (TNOA).
  • the halide group of the alkylaluminum halide may be chloride, bromide or iodide.
  • the alkylaluminum halide may be diethylaluminum chloride, diethylaluminum bromide, ethylaluminum dichloride, ethylaluminum sesquichloride or mixtures thereof.
  • the alkoxide group of the alkylaluminum alkoxide may be any C 1 to C 20 alkoxy group.
  • the alkoxy group may be methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy or octoxy.
  • the alkylaluminum alkoxide may be diethylaluminum ethoxide.
  • the aluminoxane compound may be methylaluminoxane (MAO), ethylaluminoxane, modified methylaluminoxane (MMAO), n-propylaluminoxane, iso-propyl-aluminoxane, n- butylaluminoxane, sec-butylaluminoxane, iso-butylaluminoxane, t-butylaluminoxane, 1-pentyl- aluminoxane, 2-pentyl-aluminoxane, 3-pentyl-aluminoxane, iso-pentyl-aluminoxane, neopentylaluminoxane, or mixtures thereof.
  • MAO methylaluminoxane
  • MMAO modified methylaluminoxane
  • n-propylaluminoxane iso-propyl-aluminoxane
  • the preferred co-catalyst is modified methylaluminoxane.
  • the synthesis of modified methylaluminoxane may be carried out in the presence of other trialkylaluminum compounds in addition to trimethylaluminum.
  • the products incorporate both methyl and alkyl groups from the added trialkylaluminum and are referred to as modified methyl aluminoxanes, MMAO.
  • the MMAO may be more soluble in nonpolar reaction media, more stable to storage, have enhanced performance as a cocatalyst, or any combination of these.
  • the performance of the resulting MMAO may be superior to either of the trialkylaluminum starting materials or to simple mixtures of the two starting materials.
  • the added trialkylaluminum may be triethylaluminum, triisobutylaluminum or triisooctylaluminum.
  • the co-catalyst is MMAO, wherein preferably about 25% of the methyl groups are replaced with iso-butyl groups.
  • the co-catalyst may be formed in situ in the reactor by providing the appropriate precursors into the reactor.
  • One or more solvents may be used in the reaction.
  • the solvent(s) may be used to dissolve or suspend the catalyst or the co-catalyst and/ or keep the ethylene dissolved.
  • the solvent may be any solvent that can modify the solubility of any of these components or of reaction products. Suitable solvents include hydrocarbons, for example, alkanes, alkenes, cycloalkanes, and aromatics. Different solvents may be used in the process, for example, one solvent can be used for the catalyst and another for the co-catalyst. It is preferred for the solvent to have a boiling point that is not substantially similar to the boiling point of any of the alpha olefin products as this will make the product separation step more difficult. Aromatics
  • Aromatic solvents can be any solvent that contains an aromatic hydrocarbon, preferably having a carbon number of 6 to 20. These solvents may include pure aromatics, or mixtures of pure aromatics, isomers as well as heavier solvents, for example C 9 and C 10 solvents. Suitable aromatic solvents include benzene, toluene, xylene (including ortho-xylene, meta-xylene, para-xylene and mixtures thereof) and ethylbenzene.
  • Alkane solvents may be any solvent that contains an alkyl hydrocarbon. These solvents may include straight chain alkanes and branched or iso-alkanes having from 3 to 20 carbon atoms and mixtures of these alkanes. The alkanes may be cycloalkanes.
  • Suitable solvents include propane, isobutane, n-butane, butane (n-butane or a mixture of linear and branched C 4 acyclic alkanes), pentane (n-pentane or a mixture of linear and branched acyclic alkanes), hexane (n-hexane or a mixture of linear and branched Cg acyclic alkanes), heptane (n-heptane or a mixture of linear and branched C 7 acychc alkanes), octane (n-octane or a mixture of linear and branched C 8 acyclic alkanes) and isooctane.
  • Suitable solvents also include cyclohexane and methylcyclohexane.
  • the solvent comprises C 6 , C 7 and C» alkanes, that may include linear, branched and iso-alkanes.
  • the catalyst system may be formed by mixing together the ligand, the metal, the co-catalyst and optional additional compounds in a solvent.
  • the feed may be present in this step.
  • the catalyst system may be prepared by contacting the metal or metal compound with the ligand to form a catalyst precursor mixture and then contacting the catalyst precursor mixture with the co-catalyst in the reactor to form the catalyst system.
  • the catalyst system may be prepared outside of the reactor vessel and fed into the reactor vessel. In other embodiments, the catalyst system may be formed in the reactor vessel by passing each of the components of the catalyst system separately into the reactor. In other embodiments, one or more catalyst precursors may be formed by combining at least two components outside of the reactor and then passing the one or more catalyst precursors into the reactor to form the catalyst system.
  • the oligomerization reaction is a reaction that converts the olefin feed in the presence of an oligomerization catalyst and a co-catalyst into a higher oligomer product stream.
  • the oligomerization reaction may be conducted over a range of temperatures of from -100 °C to 300 °C, preferably in the range of from 0 °C to 200 °C, and more preferably in the range of from 50 °C to 150 °C.
  • the oligomerization reaction may be conducted at a pressure of from 0.01 to 15 MPa and more preferably from 1 to 10 MPa.
  • the optimum conditions of temperature and pressure used for a specific catalyst system, to maximize the yield of oligomer, and to minimize the impact of competing reactions, for example dimerization and polymerization can be determined by one of ordinary skill in the art.
  • the temperature and pressure are selected to yield a product slate with a K-factor in the range of from 0.40 to 0.90, preferably in the range of from 0.45 to 0.80, mote preferably in the range of from 0.5 to 0.7.
  • Residence times in the reactor of from 3 to 60 min have been found to be suitable, depending on the activity of the catalyst.
  • the reaction is carried out in the absence of air and moisture.
  • the oligomerization reaction can be carried out in the liquid phase or mixed gas-liquid phase, depending on the volatility of the feed and product olefins at the reaction conditions.
  • the oligomerization reaction may be carried out in a conventional fashion. It may be carried out in a stirred tank reactor, wherein solvent, olefin and catalyst or catalyst precursors are added continuously to a stirred tank and solvent, product, catalyst, and unused reactant are removed from the stirred tank with the product separated and the unused reactant recycled back to the stirred tank.
  • the oligomerization reaction may be carried out in a batch reactor, wherein the catalyst precursors and reactant olefin are charged to an autoclave or other vessel and after being reacted for an appropriate time, product is separated from the reaction mixture by conventional means, for example, distillation.
  • the oligomerization reaction may be carried out in a gas lift reactor. This type of reactor has two vertical sections (a riser section and a downcomer section) and a gas separator at the top. The gas feed (ethylene) is injected at the bottom of the riser section to drive circulation around the loop (up the riser section and down the downcomer section).
  • the oligomerization reaction may be carried out in a pump loop reactor.
  • This type of reactor has two vertical sections, and it uses a pump to drive circulation around the loop.
  • a pump loop reactor can be operated at a higher circulation rate than a gas lift reactor.
  • the oligomerization reaction may be carried out in a once-through reactor.
  • This type of reactor feeds the catalyst, co-catalyst, solvent and ethylene to the inlet of the reactor and/ or along the reactor length and the product is collected at the reactor outlet.
  • This type of reactor is a plug flow reactor.
  • the higher oligomers produced in the ohgomerization reaction contains catalyst from the reaction step. To stop further reactions that can produce byproducts and other undesired components, it is important to deactivate the catalyst downstream from the reactor.
  • the catalyst is deactivated by addition of an acidic species having a pKA(aq) of less than 25.
  • the deactivated catalyst can then be removed by water washing in a liquid/ liquid extractor.
  • the resulting alpha-olefins have a chain length of from 4 to 100 carbon atoms, preferably 4 to 30 carbon atoms and most preferably 4 to 20 carbon atoms.
  • the alpha-olefins are even- numbered alpha-olefins.
  • the product olefins can be recovered by distiEation or other separation techniques depending on the intended use of the products.
  • the solvent(s) used in the reaction preferably have a boiling point that is different from the boiling point of any of the alpha-olefin products to make the separation easier.
  • the distiEation steps comprise columns for separating ethylene and the main linear alpha olefin products, for example, butene, hexene, and octene.
  • the products produced by the process may be used in a number of apphcations.
  • the olefins produced by this process may have improved quahties as compared to olefins produced by other processes.
  • the butene, hexene and/ or octene produced may be used as a comonomer in making polyethylene.
  • the octene produced may be used to produce plasticizer alcohols.
  • the decene produced may be used to produce polyalphaolefins.
  • the dodecene and/or tetradecene produced may be used to produce alkylbenzene and/ or detergent alcohols.
  • the hexadecene and/ or octadecene produced may be used to produce alkenyl succinates and/ or oilfield chemicals.
  • the C20+ products may be used to produce lubricant additives and/ or waxes.
  • a portion of any unreacted ethylene that is removed from the reactor with the products may be recycled to the reactor.
  • This ethylene may be recovered in the distillation steps used to separate the products.
  • the ethylene may be combined with the fresh ethylene feed or it may be fed separately to the reactor.
  • a portion of any solvent used in the reaction may be recycled to the reactor.
  • the solvent may be recovered in the distillation steps used to separate the products.
  • olefins When the olefins will be used as a comonomer in a polymerization process, it is important to produce olefins which have a lower content of dienes as the dienes can act as a catalyst poison in the polymerization reaction.
  • the selection of a suitable catalyst system and oligomerization reaction conditions impact the content and type of dienes formed in the oligomerization reaction zone.
  • the conditions should be selected such that the alpha-olefin product stream contains less than 50 ppmw of 1,3-hexadiene.
  • This diene is known to be a catalyst poison to polymerization catalysts.
  • the alpha-olefin product stream preferably contains less than 10 ppmw of 1,3-hexadiene and more preferably less than 5 ppmw of 1,3-hexadiene.
  • the alpha-olefin product stream may contain from 0 to 50 ppmw of 1,3-hexadiene, preferably from 0.1 ppbw to 10 ppmw, more preferably from 0.1 ppbw to 5 ppmw and most preferably from 0.1 ppbw to 1 ppmw of 1,3- hexadiene. Since 1,3-hexadiene is a catalyst poison, it is preferable to limit the content of that diene as much as possible, so it may be even less than 0.1 ppbw or below the detection limit of known tests.
  • the alpha-olefin product stream may be substantially free of 1,3-hexadiene.
  • the dienes that are typically measured in the product stream are those having 6 carbon atoms (C6 dienes), which includes 1,3- hexadiene; 1,4-hexadiene; 1,5 -hexadiene; 2,4-hexadiene; and 3-methyl-l,4-pentadiene.
  • the conditions should be selected such that the alpha-olefin product stream contains less than 500 ppmw of total C6 dienes, preferably less than 400 ppmw and more preferably less than 300 ppmw of total C6 dienes.
  • the content of C6 dienes in the product stream may be from 1 to 500 ppmw, preferably from 5 to 400 ppmw and more preferably from 5 to 300 ppmw.
  • the invention provides a process for producing polyethylene comprising contacting ethylene with one or more alpha-olefins in the presence of a polymerization catalyst wherein the one or more alpha-olefins are produced in the above described process where the content of dienes in the oligomerization product stream is limited as described.
  • the content of 1,3-hexadiene in the alpha-olefin product stream used as a comonomer in the polymerization process is less than 100 ppmw, preferably less than 50 ppmw, more preferably less than 10 ppmw and most preferably less than 5 ppmw.
  • the amount of 1,3-hexadiene and the content of total C6 dienes may be limited as further described above.
  • the Examples show the effect of vatious C6 dienes on a Ziegler-Natta polyethylene catalyst and a constrained geometry metallocene polyethylene catalyst.
  • the examples show that 1,3- hexadiene poisons both types of polyethylene catalyst and that other dienes had no apparent effect on either polyethylene catalyst.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Abstract

A process for producing alpha-olefins comprising contacting ethylene with an oligomerization catalyst system in an oligomerization reaction zone under oligomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises a metal-ligand complex and a co-catalyst and the oligomerization conditions are selected such that the product stream contains less than 50 ppmw of 1,3-hexadiene. A process for producing polyethylene comprising contacting ethylene with one or more alpha olefins in the presence of a polymerization catalyst wherein the one or more alpha olefins are produced in a process comprising contacting an ethylene feed with an oligomerization catalyst system in an oligomerization reaction zone under oligomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises an iron-pyridine bisimine complex and an MMAO co-catalyst and the oligomerization conditions are selected such that the one or more alpha-olefins contain less than 100 ppmw of 1,3-hexadiene.

Description

A PROCESS FORPRODUCING ALPHA-OLEFINS
Field of the Invention
The invention relates to a process for producing alpha-olefins and using those alpha-olefins in a polymerization process.
Background
The oligomerization of olefins, such as ethylene, produces butene, hexene, octene, and other valuable linear alpha olefins. Linear alpha olefins are a valuable comonomer for linear low-density polyethylene and high-density polyethylene. Such olefins are also valuable as a chemical intermediate in the production of plasticizer alcohols, fatty acids, detergent alcohols, polyalphaolefins, oil field drilling fluids, lubricant oil additives, linear alkylbenzenes, alkenylsuccinic anhydrides, alkyldimethylamines, dialkylmethylamines, alpha-olefin sulfonates, internal olefin sulfonates, chlorinated olefins, linear mercaptans, aluminum alkyls, alkyldiphenylether disulfonates, and other chemicals.
US 6,683,187 describes a bis(arylimino)pyridine ligand, catalyst precursors and catalyst systems derived from this ligand for ethylene oligomerization to form linear alpha olefins. The patent teaches the production of linear alpha olefins with a Schulz -Flory oligomerization product distribution. In such a process, a wide range of oligomers are produced, and the fraction of each olefin can be determined by calculation on the basis of the K-factor. The K-factor is the molar ratio of (Cn+2)/Cn, where n is the number of carbons in the linear alpha olefin product.
It would be advantageous to develop an improved process that would provide an oligomerization product distribution having a desired K-factor and product quality. This is especially important when the oligomerization product will be used in a polymerization process to produce polyolefins.
Summary of the Invention
The invention provides a process for producing alpha-olefins comprising contacting an ethylene feed with an oligomerization catalyst system in an oligomerization reaction zone under oligomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises a metal-ligand complex and a co-catalyst and the oEgomerization conditions are selected such that the product stream contains less than 10 ppmw of 1,3-hexadiene.
The invention further provides a process for producing polyethylene comprising contacting ethylene with one or more alpha olefins in the presence of a polymerization catalyst wherein the one or more alpha olefins are produced in a process comprising contacting an ethylene feed with an oEgomerization catalyst system in an oEgomerization reaction zone under oEgomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises an iron-pyridine bisimine complex and an MMAO co-catalyst and the oEgomerization conditions are selected such that the one or more alpha-olefins contain less than 100 ppmw of 1,3-hexadiene.
Detailed Description
The process comprises converting an olefin feed into a higher oligomer product stream by contacting the feed with an oEgomerization catalyst system and a co-catalyst in an oEgomerization reaction zone under oEgomerization conditions. In one embodiment, an ethylene feed may be contacted with an iron-Egand complex and modified methyl aluminoxane under oEgomerization conditions to produce a product slate of alpha olefins having a specific k-factor.
Olefin Feed
The olefin feed to the process comprises ethylene. The feed may also comprise olefins having from 3 to 8 carbon atoms. The ethylene may be pretreated to remove impurities, especially impurities that impact the reaction, product quaEty or damage the catalyst. In one embodiment, the ethylene may be dried to remove water. In another embodiment, the ethylene may be treated to reduce the oxygen content of the ethylene. Any pretreatment method known to one of ordinary skill in the art can be used to pretreat the feed.
Oligomerization Catalyst
The oEgomerization catalyst system may comprise one or more oEgomerization catalysts as described further herein. The oEgomerization catalyst is a metal-ligand complex that is effective for catalyzing an oEgomerization process. The ligand may comprise a bis(aryEmino)pyridine compound, a bis(alkylimino)pyridine compound or a mixed aryl-alkyl iminopyridine compound. Ligand
In one embodiment, the Egand comprises a pyridine bis(imine) group. The Egand may be a bis(arylimino)pyridine compound having the structure of Formula I.
(I)
Figure imgf000004_0001
R1, R2 and R3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R4 and R5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R6 and R7 are each independently an aryl group as shown in Formula II. The two aryl groups ( R6 and R7) on one Egand may be the same or different.
Figure imgf000004_0002
R8, R9, R10, R11, R12 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R1-R3, and R9- R11 vicinal to one another taken together may form a ring. R12 may be taken together with R11, R4 or R5 to form a ring. R2 and R4 or R3 and R5 may be taken together to form a ring. A hydrocarbyl group is a group containing only carbon and hydrogen. The number of carbon atoms in this group is preferably in the range of from 1 to 30.
An optionally substituted hydrocarbyl is a hydrocarbyl group that optionally contains one or more “inert” heteroatom-containing functional groups. Inert means that the functional groups do not interfere to any substantial degree with the oligomerization process. Examples of these inert groups include fluoride, chloride, iodide, stannanes, ethers, hydroxides, alkoxides and amines with adequate steric shielding. The optionally substituted hydrocarbyl group may include primary, secondary and tertiary carbon atoms groups.
Primary carbon atom groups are a -CH2-R group wherein R may be hydrogen, an optionally substituted hydrocarbyl or an inert functional group. Examples of primary carbon atom groups include -CH3, -C2H5, -CH2CI, -CH2OCH3, -CH2N( C2H5 and -CE2Ph. Secondary carbon atom groups are a -CH-R2 or -CH (R)(R') group wherein R and R' may be optionally substituted hydrocarbyl or an inert functional group. Examples of secondary carbon atom groups include - CH(CH3)2, -CHCI2, -CHPh2, -CH(CH3)(OCH3), -CH=CH2, and cyclohexyl. Tertiary carbon atom groups are a -C-(R)(R')(R") group wherein R, R', and R" may be optionally substituted hydrocarbyl or an inert functional group. Examples of tertiary carbon atom groups include -C(CH3)3, -CC13, - C≡CPh, 1-Adamantyl, and -C(CH3)2(OCH3)
An inert functional group is a group other than optionally substituted hydrocarbyl that is inert under the oligomerization conditions. Inert has the same meaning as provided above. Examples of inert functional groups include halide, ethers, and amines, in particular tertiary amines.
Substituent variations of R1-R5, R8-R12 and R13-R17 may be selected to enhance other properties of the ligand, for example, solubility in non-polar solvents. Several embodiments of possible oligomerization catalysts are further described below having the structure shown in Formula 3.
Figure imgf000006_0001
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11 and R14-R16 are hydrogen; and R8, R12, R13 and R17 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R12, R14 andR16 ate hydrogen; R13, R15 and R17 are methyl and R9 and R11 are tert-butyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R12, R14 and R16 are hydrogen; R13, R15 and R17 are methyl; R9 and R11 are phenyl and R10 is an alkoxy.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R11 and R14- R16 are hydrogen; R9 and R12 are methyl; and R13 and R17 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R3, R9-R11 and R14-R16 are hydrogen; R4 and R5 are phenyl and R8, R12, R13 and R17 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8- R9, R11-R12, R13- R14 and R16-R17 are hydrogen; and R10 and R15 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R12, R13, R15 and R17 are hydrogen; and R9, R11, R14 and R16 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9,R11-R12, R14 and R16-R17 are hydrogen; and R8, R10, R13 and R15 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8- R9. R11- R12, R14 and R16 are hydrogen; R10 is tert-butyl; and R13, R15 and R17 are methyl. In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12, R14 and R16 are hydrogen; R8 is fluorine; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12, R13, R15 and R17 are hydrogen; R8 is tert-butyl; and R14 and R16 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12, R13-R14 and R16-R17 are hydrogen; and R8 and R15 are tert-butyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8-R10, R13-R14 and R16-R17 are hydrogen; R15 is tert-butyl; and R11 and R12 are taken together to form an aryl group.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12, R14-R17 are hydrogen; and R8 and R13 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8-R9.R11-R12, R14 and R16 are hydrogen; R10 is fluorine; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R12, R14 and R16 are hydrogen; R9 and R11 are fluorine; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8-R9,R11-R12, R14 and R16 are hydrogen; R10 is an alkoxy; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8-R9.R11-Ru, R14 and R16 are hydrogen; R10 is a silyl ether; and R13, R15 and Ru are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R12, R14-R16 are hydrogen; R9 and R11 are methyl; and R13 and R17 are ethyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12, and R14-R17 are hydrogen; and R8 and R13 are ethyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11 and R14-R16 are hydrogen; and R8, R12, R13 and R17 are chlorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9, R11, R14 and R16 are hydrogen; and R8, R10, R12, R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R10, R12, R14-R15 and R17 are hydrogen; and R8, R11, R13 and R16 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R17 are hydrogen.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R12, R13, R15 and R17 are hydrogen; and R9, Ru, R14 and R16 are tert-butyl. In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8-R12, R14 and R16 are hydrogen; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9, R11-R12, R14 and R16 are hydrogen; R8 and R10 are fluorine; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9, R11-R12, R14 and R16-R17 are hydrogen; and R8, R10, R13 and R15 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11 and R14-R16 are hydrogen; R8 and R12 are chlorine; and R13 and R17 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8, R10, R12, R14 andR16 are hydrogen; and R9, R11, R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11 and R13-R14 and R16-R17 are hydrogen; R8 and R12 are chlorine; and R15 is tert-butyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11 and R13-R17 are hydrogen; and R8 and R12 are chlorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12, and R14-R17 are hydrogen; and R8 and R13 are chlorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9,R11-R12, R14 and R16-R17 are hydrogen; and R8, R10, R13 and R15 are chlorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9, R11-R12, and R14, and R16- R17 are hydrogen; R10 and R15 are methyl; and R8 and R13 are chlorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11 and R13-R14 and R16- R17 are hydrogen; R15 is fluorine; and R8 and R12 are chlorine.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R8-R9, R11-R12, R14- R15 and R17 are hydrogen; R10 is tert-butyl; and R13 and R16 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R11, R14 and R16 are hydrogen; R8 and R12 are fluorine; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R10, R12, R14-R15 and R17 are hydrogen; R8 and R13 are methyl; and R11 and R16, are isopropyl.
In one embodiment, a ligand of Formula III is provided wherein R1-R5, R9-R12 and R14- R16 are hydrogen; R8 is ethyl; and R13 and R17 are fluorine.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R9-R10, R12, R14-R15 and R17 are hydrogen; R1 is methoxy; and R8, R11, R13 and R16 are methyl. In one embodiment, a ligand of Formula III is provided wherein R2-R5, R8-R12, R14 and R16 are hydrogen; R1 is methoxy; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R9-R12, and R14-R17 are hydrogen; R1 is methoxy; and R8 and R13 are ethyl.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R9, R11-R12, R14 and R16-R17 are hydrogen; R1 is tert-butyl; and R8, R10, R13 and R15 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R8-R12, R14 and R16 are hydrogen; R1 is tert-butyl; and R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R9, R11, R14 and R16 are hydrogen; R1 is methoxy; and R8, R10, R12, R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R9, R11, R14 and R16 are hydrogen; R1 is alkoxy; and R8, R10, R12, R13, R15 and R17 are methyl.
In one embodiment, a ligand of Formula III is provided wherein R2-R5, R9, R11, R14 and R16 are hydrogen; R1 is tert-butyl; and R8, R10, R12, R13, R15 and R17 are methyl.
In another embodiment, the ligand may be a compound having the structure of Formula I, wherein one of R6 and R7 is aryl as shown in Formula II and one of R6 and R7 is pyridyl as shown in Formula IV. In another embodiment, R6 and R7 may be pyrrolyl.
(IV)
Figure imgf000009_0001
R1, R2 and R3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R4 and R5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R8-R12 and R18-R21 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R1-R3, and R9-R11 vicinal to one another taken together may form a ring. R12 may be taken together with R11, R4 or R5 to form a ring. R2 and R4 or R3 and R5 may be taken together to form a ring.
Figure imgf000010_0001
In one embodiment, a ligand of Formula V is provided wherein R1-R5, R9, R11 and R18-R21 are hydrogen; and R8, R10, and R12 are methyl.
In one embodiment, a ligand of Formula V is provided wherein R1-R5, R9-R11 and R18-R21 are hydrogen; and R8 and R12 are ethyl.
In another embodiment, the ligand may be a compound having the structure of Formula I, wherein one of R6 and R7 is aryl as shown in Formula II and one of R8 and R7 is cyclohexyl as shown in Formula VI. In another embodiment, R6 and R7 may be cyclohexyl.
Figure imgf000011_0001
R1, R2 and R3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R4 and R5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R8-R12 and R22-R26 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R1-R3, and R9-R11 vicinal to one another taken together may form a ring. R12 may be taken together with R11, R4 or R5 to form a ring. R2 and R4 or R3 and R5 may
Figure imgf000011_0002
In one embodiment, a ligand of Formula VII is provided wherein R1-R5, R9, R11 and R22-R26 are hydrogen; and R8, R10, and R12 are methyl. In another embodiment, R6 and R7 may be adamantyl or another cycloalkane.
In another embodiment, the ligand may be a compound having the structure of Formula I, wherein one of R6 and R7 is aryl as shown in Formula II and one of R6 and R7 is ferrocenyl as shown in Formula VIII. In another embodiment, R6 and R7 may be ferrocenyl.
Figure imgf000012_0001
R1, R2 and R3 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R4 and R5 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano or an inert functional group. R8- R12 and R27 -R35 are each independently hydrogen, optionally substituted hydrocarbyl, hydroxo, cyano, an inert functional group, fluorine, or chlorine. Any two of R1-R3, and R9-R11 vicinal to one another taken together may form a ring. R12 may be taken together with R11, R4 or R5 to form a ring. R2 and R4 or R3 and R5 may be taken together to form a ring.
Figure imgf000013_0001
embodiment, a ligand of Formula IX is provided wherein R1-R5, R9, R11 and R27 -R35 are hydrogen; and R8, R10, and R12 are methyl.
In one embodiment, a ligand of Formula IX is provided wherein R1-R5, R9-R11, and R27 -R35 are hydrogen; and R8 and R12 are ethyl.
In another embodiment, the ligand may be a bis(alkylamino)pyridine. The alkyl group may have from 1 to 50 carbon atoms. The alkyl group may be a primary, secondary, or tertiary alkyl group. The alkyl group may be selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, and tert-butyl. The alkyl group may be selected from any n-alkyl or structural isomer of an n-alkyl having 5 or more carbon atoms, e.g., n-pentyl; 2-methyl-butyl; and 2,2-dimethylpropyl.
In another embodiment, the ligand may be an alkyl-alkyl iminopyridine, where the two alkyl groups are different. Any of the alkyl groups described above as being suitable for a bis(alkylamino)pyridine are also suitable for this alkyl-alkyl iminopyridine.
In another embodiment, the ligand may be an aryl alkyl iminopyridine. The aryl group may be of a similar nature to any of the aryl groups described with respect to the bis(arylimino)pyridine compound and the alkyl group may be of a similar nature to any of the alkyl groups described with respect to the bis(alkylamino)pyridine compound. In addition to the ligand structures described hereinabove, any structure that combines features of any two or more of these ligands can be a suitable ligand for this process. Further, the oligomerization catalyst system may comprise a combination of one or more of any of the described oligomerizations catalysts.
The ligand feedstock may contain between 0 and 10 wt.% bisimine pyridine impurity, preferably 0-1 wt.% bisimine pyridine impurity, most preferably 0-0.1 wt.% bisimine pyridine impurity. This impurity is believed to cause the formation of polymers in the reactor, so it is preferable to limit the amount of this impurity that is present in the catalyst system.
In one embodiment, the bisimine pyridine impurity is a ligand of Formula II in which three of R8, R12, R13, and R17 are each independently optionally substituted hydrocarbyl.
In one embodiment, the bisimine pyridine impurity is a ligand of Formula II in which all four of R8, R12, R13, and R17 are each independently optionally substituted hydrocarbyl.
Metal
The metal may be a transition metal, and the metal is preferably present as a compound having the formula MXn, where M is the metal, X is a monoanion and n represents the number of monoanions (and the oxidation state of the metal).
The metal can comprise any Group 4-10 transition metal. The metal can be selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, palladium, platinum, ruthenium and rhodium. In one embodiment, the metal is cobalt or iron. In a preferred embodiment, the metal is iron. The metal of the metal compound can have any positive formal oxidation state of from 2 to 6 and is preferably 2 or 3.
The monoanion may comprise a halide, a carboxylate, a β-diketonate, a hydrocarboxide, an optionally substituted hydrocarbyl, an amide or a hydride. The hydrocarboxide may be an alkoxide, an aryloxide or an aralkoxide. The halide may be fluorine, chlorine, bromine or iodine.
The carboxylate may be any C1 to C20 carboxylate. The carboxylate may be acetate, a propionate, a butyrate, a pentanoate, a hexanoate, a heptanoate, an octanoate, a nonanoate, a decanoate, an undecanoate, or a dodecanoate. In addition, the carboxylate may be 2-ethylhexanoate or trifluoroacetate.
The β-diketonate may be any C1 to C20 [3-diketonate. The β-diketonate may be acetylacetonate, hexafluoroacetylacetonate, or benzoylacetonate. The hydrocarboxide may be any C1 to C20 hydrocarboxide. The hydrocarboxide may be a Ci to C20 alkoxide, or a C6 to C20 aryloxide. The alkoxide may be methoxide, ethoxide, a propoxide (e.g., iso-propoxide) or a butoxide (e.g., tert-butoxide). The aryloxide may be phenoxide
Generally, the number of monoanions equals the formal oxidation state of the metal atom.
Preferred embodiments of metal compounds include iron acetylacetonate, iron chloride, and iron bis(2-ethylhexanoate). In addition to the oligomerization catalyst, a co-catalyst is used in the oligomerization reaction.
Co-catalyst
The co-catalyst may be a compound that is capable of transferring an optionally substituted hydrocarbyl or hydride group to the metal atom of the catalyst and is also capable of abstracting an X' group from the metal atom M. The co-catalyst may also be capable of serving as an electron transfer reagent or providing sterically hindered counterions for an active catalyst.
The co-catalyst may comprise two compounds, for example one compound that is capable of transferring an optionally substituted hydrocarbyl or hydride group to metal atom M and another compound that is capable of abstracting an X group from metal atom M. Suitable compounds for transferring an optionally substituted hydrocarbyl or hydride group to metal atom M include organoaluminum compounds, alkyl lithium compounds, Grignards, alkyl tin and alkyl zinc compounds. Suitable compounds for abstracting an X group from metal atom M include strong neutral Lewis acids such as SbF5, BF3 and Ar3B wherein Ar is a strong electron-withdrawing aryl group such as C6F5 or 3,5-(CF3)2C6H3. A neutral Lewis acid donor molecule is a compound which may suitably act as a Lewis base, such as ethers, amines, sulfides and organic nitrites.
The co-catalyst is preferably an organoaluminum compound which may comprise an alkylaluminum compound, an aluminoxane or a combination thereof.
The alkylaluminum compound may be trialkylaluminum, an alkylaluminum halide, an alkylaluminum alkoxide or a combination thereof. The alkyl group of the alkylaluminum compound may be any C1 to C20 alkyl group. The alkyl group may be methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. The alkyl group may be an iso-alkyl group.
The trialkylaluminum compound may comprise trimcthylaluminum (TMA), triethylaluminum (TEA), triptopylaluminum, tributylaluminum, tripentylaluminum, trihexylaluminum, triheptylaluminum, trioctylaluminum or mixtures thereof. The trialkylaluminum compound may comprise tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA), tri-iso- butylaluminum (TIB A), tri-n-hexylaluminum, tri-n-octylaluminum (TNOA). The halide group of the alkylaluminum halide may be chloride, bromide or iodide. The alkylaluminum halide may be diethylaluminum chloride, diethylaluminum bromide, ethylaluminum dichloride, ethylaluminum sesquichloride or mixtures thereof.
The alkoxide group of the alkylaluminum alkoxide may be any C1 to C20 alkoxy group. The alkoxy group may be methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy or octoxy. The alkylaluminum alkoxide may be diethylaluminum ethoxide.
The aluminoxane compound may be methylaluminoxane (MAO), ethylaluminoxane, modified methylaluminoxane (MMAO), n-propylaluminoxane, iso-propyl-aluminoxane, n- butylaluminoxane, sec-butylaluminoxane, iso-butylaluminoxane, t-butylaluminoxane, 1-pentyl- aluminoxane, 2-pentyl-aluminoxane, 3-pentyl-aluminoxane, iso-pentyl-aluminoxane, neopentylaluminoxane, or mixtures thereof.
The preferred co-catalyst is modified methylaluminoxane. The synthesis of modified methylaluminoxane may be carried out in the presence of other trialkylaluminum compounds in addition to trimethylaluminum. The products incorporate both methyl and alkyl groups from the added trialkylaluminum and are referred to as modified methyl aluminoxanes, MMAO. The MMAO may be more soluble in nonpolar reaction media, more stable to storage, have enhanced performance as a cocatalyst, or any combination of these. The performance of the resulting MMAO may be superior to either of the trialkylaluminum starting materials or to simple mixtures of the two starting materials. The added trialkylaluminum may be triethylaluminum, triisobutylaluminum or triisooctylaluminum. In one embodiment, the co-catalyst is MMAO, wherein preferably about 25% of the methyl groups are replaced with iso-butyl groups.
In one embodiment, the co-catalyst may be formed in situ in the reactor by providing the appropriate precursors into the reactor.
Solvent
One or more solvents may be used in the reaction. The solvent(s) may be used to dissolve or suspend the catalyst or the co-catalyst and/ or keep the ethylene dissolved. The solvent may be any solvent that can modify the solubility of any of these components or of reaction products. Suitable solvents include hydrocarbons, for example, alkanes, alkenes, cycloalkanes, and aromatics. Different solvents may be used in the process, for example, one solvent can be used for the catalyst and another for the co-catalyst. It is preferred for the solvent to have a boiling point that is not substantially similar to the boiling point of any of the alpha olefin products as this will make the product separation step more difficult. Aromatics
Aromatic solvents can be any solvent that contains an aromatic hydrocarbon, preferably having a carbon number of 6 to 20. These solvents may include pure aromatics, or mixtures of pure aromatics, isomers as well as heavier solvents, for example C9 and C10 solvents. Suitable aromatic solvents include benzene, toluene, xylene (including ortho-xylene, meta-xylene, para-xylene and mixtures thereof) and ethylbenzene.
Alkanes
Alkane solvents may be any solvent that contains an alkyl hydrocarbon. These solvents may include straight chain alkanes and branched or iso-alkanes having from 3 to 20 carbon atoms and mixtures of these alkanes. The alkanes may be cycloalkanes. Suitable solvents include propane, isobutane, n-butane, butane (n-butane or a mixture of linear and branched C4 acyclic alkanes), pentane (n-pentane or a mixture of linear and branched acyclic alkanes), hexane (n-hexane or a mixture of linear and branched Cg acyclic alkanes), heptane (n-heptane or a mixture of linear and branched C7 acychc alkanes), octane (n-octane or a mixture of linear and branched C8 acyclic alkanes) and isooctane. Suitable solvents also include cyclohexane and methylcyclohexane. In one embodiment, the solvent comprises C6, C7 and C» alkanes, that may include linear, branched and iso-alkanes.
Catalyst System
The catalyst system may be formed by mixing together the ligand, the metal, the co-catalyst and optional additional compounds in a solvent. The feed may be present in this step.
In one embodiment, the catalyst system may be prepared by contacting the metal or metal compound with the ligand to form a catalyst precursor mixture and then contacting the catalyst precursor mixture with the co-catalyst in the reactor to form the catalyst system.
In some embodiments, the catalyst system may be prepared outside of the reactor vessel and fed into the reactor vessel. In other embodiments, the catalyst system may be formed in the reactor vessel by passing each of the components of the catalyst system separately into the reactor. In other embodiments, one or more catalyst precursors may be formed by combining at least two components outside of the reactor and then passing the one or more catalyst precursors into the reactor to form the catalyst system.
Reaction Conditions
The oligomerization reaction is a reaction that converts the olefin feed in the presence of an oligomerization catalyst and a co-catalyst into a higher oligomer product stream. Temperature
The oligomerization reaction may be conducted over a range of temperatures of from -100 °C to 300 °C, preferably in the range of from 0 °C to 200 °C, and more preferably in the range of from 50 °C to 150 °C.
Pressure
The oligomerization reaction may be conducted at a pressure of from 0.01 to 15 MPa and more preferably from 1 to 10 MPa.
The optimum conditions of temperature and pressure used for a specific catalyst system, to maximize the yield of oligomer, and to minimize the impact of competing reactions, for example dimerization and polymerization can be determined by one of ordinary skill in the art. The temperature and pressure are selected to yield a product slate with a K-factor in the range of from 0.40 to 0.90, preferably in the range of from 0.45 to 0.80, mote preferably in the range of from 0.5 to 0.7.
Residence Time
Residence times in the reactor of from 3 to 60 min have been found to be suitable, depending on the activity of the catalyst. In one embodiment, the reaction is carried out in the absence of air and moisture.
Gas Phase, Liquid Phase or Mixed Gas-Liquid Phase
The oligomerization reaction can be carried out in the liquid phase or mixed gas-liquid phase, depending on the volatility of the feed and product olefins at the reaction conditions.
Reactor type
The oligomerization reaction may be carried out in a conventional fashion. It may be carried out in a stirred tank reactor, wherein solvent, olefin and catalyst or catalyst precursors are added continuously to a stirred tank and solvent, product, catalyst, and unused reactant are removed from the stirred tank with the product separated and the unused reactant recycled back to the stirred tank.
In another embodiment, the oligomerization reaction may be carried out in a batch reactor, wherein the catalyst precursors and reactant olefin are charged to an autoclave or other vessel and after being reacted for an appropriate time, product is separated from the reaction mixture by conventional means, for example, distillation. In another embodiment, the oligomerization reaction may be carried out in a gas lift reactor. This type of reactor has two vertical sections (a riser section and a downcomer section) and a gas separator at the top. The gas feed (ethylene) is injected at the bottom of the riser section to drive circulation around the loop (up the riser section and down the downcomer section).
In another embodiment, the oligomerization reaction may be carried out in a pump loop reactor. This type of reactor has two vertical sections, and it uses a pump to drive circulation around the loop. A pump loop reactor can be operated at a higher circulation rate than a gas lift reactor.
In another embodiment, the oligomerization reaction may be carried out in a once-through reactor. This type of reactor feeds the catalyst, co-catalyst, solvent and ethylene to the inlet of the reactor and/ or along the reactor length and the product is collected at the reactor outlet. One example of this type of reactor is a plug flow reactor.
Catalyst Deactivation
The higher oligomers produced in the ohgomerization reaction contains catalyst from the reaction step. To stop further reactions that can produce byproducts and other undesired components, it is important to deactivate the catalyst downstream from the reactor.
In one embodiment, the catalyst is deactivated by addition of an acidic species having a pKA(aq) of less than 25. The deactivated catalyst can then be removed by water washing in a liquid/ liquid extractor.
Product Separation
The resulting alpha-olefins have a chain length of from 4 to 100 carbon atoms, preferably 4 to 30 carbon atoms and most preferably 4 to 20 carbon atoms. The alpha-olefins are even- numbered alpha-olefins.
The product olefins can be recovered by distiEation or other separation techniques depending on the intended use of the products. The solvent(s) used in the reaction preferably have a boiling point that is different from the boiling point of any of the alpha-olefin products to make the separation easier.
In one embodiment, the distiEation steps comprise columns for separating ethylene and the main linear alpha olefin products, for example, butene, hexene, and octene.
Product qualities and characteristics
The products produced by the process may be used in a number of apphcations. The olefins produced by this process may have improved quahties as compared to olefins produced by other processes. In one embodiment, the butene, hexene and/ or octene produced may be used as a comonomer in making polyethylene. In one embodiment, the octene produced may be used to produce plasticizer alcohols. In one embodiment, the decene produced may be used to produce polyalphaolefins. In one embodiment, the dodecene and/or tetradecene produced may be used to produce alkylbenzene and/ or detergent alcohols. In one embodiment, the hexadecene and/ or octadecene produced may be used to produce alkenyl succinates and/ or oilfield chemicals. In one embodiment, the C20+ products may be used to produce lubricant additives and/ or waxes.
Recycle
A portion of any unreacted ethylene that is removed from the reactor with the products may be recycled to the reactor. This ethylene may be recovered in the distillation steps used to separate the products. The ethylene may be combined with the fresh ethylene feed or it may be fed separately to the reactor.
A portion of any solvent used in the reaction may be recycled to the reactor. The solvent may be recovered in the distillation steps used to separate the products.
Dienes
When the olefins will be used as a comonomer in a polymerization process, it is important to produce olefins which have a lower content of dienes as the dienes can act as a catalyst poison in the polymerization reaction. The selection of a suitable catalyst system and oligomerization reaction conditions impact the content and type of dienes formed in the oligomerization reaction zone.
The conditions should be selected such that the alpha-olefin product stream contains less than 50 ppmw of 1,3-hexadiene. This diene is known to be a catalyst poison to polymerization catalysts. The alpha-olefin product stream preferably contains less than 10 ppmw of 1,3-hexadiene and more preferably less than 5 ppmw of 1,3-hexadiene. The alpha-olefin product stream may contain from 0 to 50 ppmw of 1,3-hexadiene, preferably from 0.1 ppbw to 10 ppmw, more preferably from 0.1 ppbw to 5 ppmw and most preferably from 0.1 ppbw to 1 ppmw of 1,3- hexadiene. Since 1,3-hexadiene is a catalyst poison, it is preferable to limit the content of that diene as much as possible, so it may be even less than 0.1 ppbw or below the detection limit of known tests. The alpha-olefin product stream may be substantially free of 1,3-hexadiene.
In addition, it is preferred to limit the total content of dienes. The dienes that are typically measured in the product stream are those having 6 carbon atoms (C6 dienes), which includes 1,3- hexadiene; 1,4-hexadiene; 1,5 -hexadiene; 2,4-hexadiene; and 3-methyl-l,4-pentadiene. The conditions should be selected such that the alpha-olefin product stream contains less than 500 ppmw of total C6 dienes, preferably less than 400 ppmw and more preferably less than 300 ppmw of total C6 dienes. The content of C6 dienes in the product stream may be from 1 to 500 ppmw, preferably from 5 to 400 ppmw and more preferably from 5 to 300 ppmw.
In one embodiment, the invention provides a process for producing polyethylene comprising contacting ethylene with one or more alpha-olefins in the presence of a polymerization catalyst wherein the one or more alpha-olefins are produced in the above described process where the content of dienes in the oligomerization product stream is limited as described. The content of 1,3-hexadiene in the alpha-olefin product stream used as a comonomer in the polymerization process is less than 100 ppmw, preferably less than 50 ppmw, more preferably less than 10 ppmw and most preferably less than 5 ppmw. The amount of 1,3-hexadiene and the content of total C6 dienes may be limited as further described above.
Examples
Example 1
In this Example, a number of tests were carried out to measure the effect of 1,3-hexadiene on the polyethylene reaction using a Ziegler-Natta polyethylene catalyst. The tests were carried out in a 35 mL glass pressure tube. The tests were all conducted with 8 grams of purified 1 -hexene, 2 grams of decane to disperse the catalyst, and using diethylaluminum chloride (DEAC) as co-catalyst. The tests were carried out by adding the catalyst (0.1 mmol Ti) and the decane to the pressure tube. The pressure tube was stirred for 26 minutes to disperse the catalyst. The DEAC was then added and stirred for 20 minutes. All of this was done at ambient temperature. Next, the hexene was added and the temperature was measured to evaluate the exotherm caused by the reaction. The results are shown in Table 1.
Table 1
Figure imgf000021_0001
Figure imgf000022_0001
As can be seen from Table 1, the presence of 1,3-hexadiene at levels greater than 20 ppm, and especially above 50 ppm has a negative impact on the polymerization reaction.
Example 2
In this Example, a number of tests were carried out to measure the effect of C6 dienes, including 1,3-hexadiene, on the polyethylene reaction using a constrained geometry metallocene polyethylene catalyst. The tests were carried out in a 35 mL glass pressure tube. The tests were all conducted with 8 grams of purified 1 -hexene, 2 grams of decane to disperse the catalyst, and using modified methyl-aluminoxane (MMAO-12 from Nouryon) as co-catalyst. The tests were carried out by adding the catalyst (0.114 mmol Ti) and the decane to the pressure tube. The pressure tube was stirred for 2 minutes to dissolve the catalyst. The MMAO-12 was then added and stirred for 2 minutes. All of this was done at ambient temperature. Next, the hexene was added and the temperature was measured to evaluate the exotherm caused by the reaction. The results are shown in Table 2.
Table 2
Figure imgf000022_0002
Figure imgf000023_0001
The Examples show the effect of vatious C6 dienes on a Ziegler-Natta polyethylene catalyst and a constrained geometry metallocene polyethylene catalyst. The examples show that 1,3- hexadiene poisons both types of polyethylene catalyst and that other dienes had no apparent effect on either polyethylene catalyst.

Claims

1. A process for producing alpha-olefins comprising contacting an ethylene feed with an oligomerization catalyst system in an oligomerization reaction zone under oligomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises a metal-ligand complex and a co-catalyst and the oligomerization conditions are selected such that the product stream contains less than 50 ppmw of 1,3-hexadiene.
2. The process of claim 1 wherein the metal is iron, the ligand is a pyridine bisimine and the cocatalyst comprises modified methyl aluminoxane (MMAO).
3. The process of any of claims 1-2 wherein the product stream comprises alpha olefins and dienes.
4. The process of claim 3 wherein the product stream contains one or more dienes having 6 carbon atoms selected from the group consisting of 1,3-hexadiene; 1,4-hexadiene; 1,5- hexadiene; 2,4-hexadiene; and 3-methyl-l,4-pentadiene.
5. The process of claim 4 wherein the product stream comprises less than 400 ppmw of total dienes having 6 carbon atoms.
6. The process of any of claims 4-5 wherein the product stream comprises from 5 to 400 ppmw of total dienes having 6 carbon atoms
7. The process of any of claims 4-6 wherein the product stream comprises less than 10 ppmw 1,3 hexadiene.
8. The process of any of claims 4-7 wherein the product stream comprises less than 5 ppmw 1,3 hexadiene.
9. The process of any of claims 4-8 wherein the product stream is substantially free of 1,3- hexadiene.
10. A process for producing polyethylene comprising contacting ethylene with one or more alpha olefins in the presence of a polymerization catalyst wherein the one or more alpha olefins are produced in a process comprising contacting an ethylene feed with an oligomerization catalyst system in an oligomerization reaction zone under oligomerization conditions to produce a product stream comprising alpha-olefins wherein the oligomerization catalyst system comprises an iron-pyridine bisimine complex and an MMAO co-catalyst and the oligomerization conditions are selected such that the one or more alphaolefins contain less than 100 ppmw of 1,3-hexadiene.
11. The process of claim 9 wherein the polymerization catalyst is a metallocene or Ziegler-Natta catalyst.
PCT/US2021/063455 2020-12-15 2021-12-15 A process for producing alpha-olefins WO2022132865A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202063125640P 2020-12-15 2020-12-15
US63/125,640 2020-12-15

Publications (1)

Publication Number Publication Date
WO2022132865A1 true WO2022132865A1 (en) 2022-06-23

Family

ID=79288114

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2021/063455 WO2022132865A1 (en) 2020-12-15 2021-12-15 A process for producing alpha-olefins

Country Status (2)

Country Link
AR (1) AR124321A1 (en)
WO (1) WO2022132865A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000058320A1 (en) * 1999-03-29 2000-10-05 Bp Chemicals Limited Pyridine.imine polymerisation catalysts
US6683187B2 (en) 2000-06-30 2004-01-27 Shell Oil Company Ligands and catalyst systems thereof for ethylene oligomerization to linear alpha olefins
US20180051103A1 (en) * 2015-03-17 2018-02-22 Jxtg Nippon Oil & Energy Corporation Oligomer production method and catalyst

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000058320A1 (en) * 1999-03-29 2000-10-05 Bp Chemicals Limited Pyridine.imine polymerisation catalysts
US6683187B2 (en) 2000-06-30 2004-01-27 Shell Oil Company Ligands and catalyst systems thereof for ethylene oligomerization to linear alpha olefins
US20180051103A1 (en) * 2015-03-17 2018-02-22 Jxtg Nippon Oil & Energy Corporation Oligomer production method and catalyst

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SMALL ET AL: "Iron-Based Catalysts with Exceptionally High Activities and Selectivities for Oligomerization of Ethylene to Linear.alpha.-Olefins", JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, AMERICAN CHEMICAL SOCIETY, vol. 120, no. 28, 22 July 1998 (1998-07-22), XP002086898, ISSN: 0002-7863, DOI: 10.1021/JA981317Q *

Also Published As

Publication number Publication date
AR124321A1 (en) 2023-03-15

Similar Documents

Publication Publication Date Title
JP4857269B2 (en) Process for the preparation of linear alpha olefins
EP0257696B1 (en) Process for dimerizing alpha-olefins
EP0268214A1 (en) Process for producing propylene oligomers
US20240002316A1 (en) A process for producing alpha-olefins
EP1648846A1 (en) Process for producing linear alpha olefins
US20230406787A1 (en) A process for producing alpha-olefins
WO2022132865A1 (en) A process for producing alpha-olefins
US10308563B2 (en) Process for producing ethylene oligomers
US20230416171A1 (en) A process for producing alpha-olefins
WO2022132866A1 (en) A process for producing alpha-olefins
WO2022132711A1 (en) A process for producing alpha-olefins
WO2022132707A1 (en) An oligomerization catalyst, method of preparation and process for using the catalyst
WO2022132749A1 (en) A process for producing alpha-olefins
US20240018069A1 (en) A process for producing alpha olefins
US20230416170A1 (en) A process for producing alpha olefins
WO2022132860A1 (en) A process for producing alpha olefins
WO2022132743A2 (en) A process for producing alpha-olefins
CN109701644B (en) Catalyst composition and application thereof
CN109701643B (en) Catalyst composition and application thereof
CN109701660B (en) Catalyst composition and application thereof
CN107282114B (en) Catalyst composition for ethylene trimerization and application thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21840371

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21840371

Country of ref document: EP

Kind code of ref document: A1