# US 11,440,857 B2 · Catalyst systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,857 B2 - Document ID: US11440857B2 - Status: Granted - Kind: B2 - Application number: 17/537,627 - Filed: 2021-11-30 - Published: 2022-06-02 - Granted: 2022-09-13 - Earliest claimed: 2020-11-30 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Motaz Khawaji; Sohel Shaikh; Wei Xu - Web page: https://patentgrep.com/patent/US11440857B2 ## CPC - B01J 31/0209: {Esters of carboxylic or carbonic acids} - C07C 2/36: as phosphines, arsines, stilbines or bismuthines - B01J 31/0231: {Halogen-containing compounds} - B01J 31/0239: {Quaternary ammonium compounds} - B01J 31/143: {of aluminium} - B01J 31/188: {Amide derivatives thereof} - B01J 31/2213: {At least two complexing oxygen atoms present in an at least bidentate or bridging ligand} - B01J 31/2409: {with more than one complexing phosphine-P atom} - B01J 2231/20: Olefin oligomerisation or telomerisation - B01J 2531/31: Aluminium - B01J 2531/62: Chromium - C07C 2531/14: of aluminium or boron - C07C 2531/24: Phosphines - C07C 2531/26: containing in addition, inorganic metal compounds not provided for in groups C07C2531/02 - C07C2531/24 - Y02P 20/52: using catalysts, e.g. selective catalysts - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst including a reaction product of a chromium compound and a ligand having the structure according to Formula (II). In Formula (II), A and C may be independently chosen from phosphorus, arsenic, antimony, bismuth, and nitrogen; B may be a linking group between A and C; and R1, R2, R3, and R4 may be independently chosen from a (C1-C50) hydrocarbyl or a (C1-C50) heterohydrocarbyl. The catalyst system may include a co-catalyst including a reaction product of an organoaluminum compound and an antifouling compound. The antifouling compound may include one or more quaternary salts; one or more organic acids, organic acid salts, esters, anhydrides, or combinations of these; one or more chlorinated hydrocarbons, chloro-aluminum alkyls, or combinations of these; one or more polyether alcohols; or one or more non-polymeric ethers. ## Claims ### Claim 1 A catalyst system suitable for tetramerizing ethylene to form 1-octene, the catalyst system comprising: a catalyst comprising a reaction product of a chromium compound and a ligand having the structure: (R1)(R2)A-B-C(R3)(R4) wherein: A and C are independently chosen from phosphorus, arsenic, antimony, bismuth, and nitrogen; B is a linking group between A and C; R1, R2, R3, and R4 are independently chosen from a (C1-C50) hydrocarbyl or a (C1-C50) heterohydrocarbyl; and a co-catalyst comprising a reaction product of an organoaluminum compound and an antifouling compound, wherein the antifouling compound comprises: one or more quaternary salts; one or more organic acids, organic acid salts, esters, anhydrides, or combinations of these; one or more chlorinated hydrocarbons, chloro-aluminum alkyls, or combinations of these; one or more polyether alcohols; or one or more non-polymeric ethers. ### Claim 2 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more quaternary salts. ### Claim 3 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more organic acids. ### Claim 4 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more organic acid salts. ### Claim 5 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more esters. ### Claim 6 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more anhydrides. ### Claim 7 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more chlorinated hydrocarbons. ### Claim 8 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more chloro-aluminum alkyls. ### Claim 9 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more polyether alcohols. ### Claim 10 (depends on 1) The catalyst system of claim 1, wherein the antifouling compound comprises one or more non-polymeric ethers. ### Claim 11 (depends on 1) The catalyst system of claim 1, wherein the chromium compound comprises one or more of an organic chromium salt, an inorganic chromium salt, and a chromium complex. ### Claim 12 (depends on 1) The catalyst system of claim 1, wherein the chromium compound comprises one or more of chromium trichloride tris-tetrahydrofuran complex, (benzene)tricarbonyl chromium, chromium (III) octanoate, chromium (III) acetylacetonoate, chromium hexacarbonyl, and chromium (III) 2-ethylhexanoate. ### Claim 13 (depends on 1) The catalyst system of claim 1, wherein the organoaluminum compound has the structure: wherein R6, R7, and R8 are each selected from a hydrogen atom and a (C1-C20) hydrocarbyl group. ### Claim 14 (depends on 1) The catalyst system of claim 1, wherein the organoaluminum compound comprises one or more of trimethylaluminium, triethylaluminum, tripropylaluminum, tri-iso-butylaluminum, diisobutylaluminium hydride, trihexylaluminum, tri-n-octylaluminium, methylaluminium dichloride, ethylaluminium dichloride, dimethylaluminium chloride, diethylaluminium chloride, aluminium isopropoxide, ethylaluminiumsesquichloride, methylaluminiumsesquichloride, methylaluminoxane (MAO), ethylaluminoxane (EAO), and modified methylaluminoxane (MMAO). ### Claim 15 (depends on 1) The catalyst system of claim 1, wherein the co-catalyst comprises a reaction product of the antifouling compound and methylaluminoxane. ### Claim 16 (depends on 1) The catalyst system of claim 1, wherein the co-catalyst comprises a reaction product of the antifouling compound, methylaluminoxane, and an alkyl aluminum compound. ### Claim 17 (depends on 1) The catalyst system of claim 1, wherein the molar ratio of the antifouling compound to the organoaluminum complex is from 0.001 to 1. ### Claim 18 (depends on 1) A method for tetramerizing ethylene to form 1-octene, the method comprising contacting ethylene with a catalyst system of any of claim 1 to form a product comprising 1-octene. ### Claim 19 (depends on 18) The method of claim 18, wherein the ethylene is formed in the conditions of: a reactor pressure from 5 bar to 120 bar; and a reactor temperature from 25° C. to 180° C.