Process And Catalyst Composition For Producing Linear Alpha Olefins In High Yield By Ethylene Oligomerization

Abstract

The present disclosure relates to a process for producing linear alpha olefins in high yield carried out by oligomerization of ethylene in the presence of a novel catalyst composition. The catalyst composition includes Zirconium compound, an organoaluminum compound, and at least one Lewis base selected from cyclic and acyclic ethers (i.e., di-n-butyl ether and diethyl ether). The process for oligomerization of ethylene is carried out in an inert organic solvent in the presence of said catalyst composition. The process as disclosed herein provides significantly high activity of the said catalyst composition resulting in high yield of the alpha olefins (>95 wt. %) as the product and significantly minimum polymer as by-product. The process provides higher yield of C6-C10 fraction with >60 wt. %.

Claims

1. A catalyst composition for producing linear alpha olefins by oligomerization of ethylene, the catalyst composition comprising: (i) a zirconium compound having a formula ZrX.sub.m.nA, wherein X is a halogen atom, m is an integer having a value equal to or less than 4, n is a number equal to or less than 2, and A is selected from the group consisting of tetrahydrofuran, N,N-diisobutylacetamide and a combination thereof; (ii) an organoaluminum compound having a formula R.sup.1.sub.nAlY.sub.3-n, or a formula Al.sub.2Y.sub.3R.sup.1.sub.3, wherein le represents an alkyl group having 1 to 20 carbon atoms, Y represents Cl, Br, or I, n is a number 1<n<2; and (iii) at least one Lewis base, wherein the Lewis base is selected from a group consisting of cyclic and acyclic ethers.

2. The catalyst composition as claimed in claim 1, wherein the zirconium compound is tetrachlorobis(tetrahydrofuran) zirconium (ZrCl.sub.4.2THF), ZrCl.sub.4.2(N,N-diisobutylacetamide), or a combination thereof.

3. The catalyst composition as claimed in claim 1, wherein the organoaluminum compound is selected from the group consisting of diethylaluminum chloride, ethylaluminum sesquichloride and a mixture thereof.

4. The catalyst composition as claimed in claim 1, wherein aluminum present in the organoaluminum compound and zirconium present in the zirconium compound are in a mole ratio in a range of 10:1 to 70:1.

5. The catalyst composition as claimed in claim 1, wherein the cyclic and acyclic ethers are at least one of cycloaliphatic ethers, aromatic ethers, monoethers, diethers, tetraethers and polyethers.

6. The catalyst composition as claimed in claim 1, wherein the cyclic and acyclic ethers are selected from the group consisting of diethyl ether, di-n-butyl ether, di-n-propyl ether, diisobutyl ether, diisopropyl ether, diphenyl ether, methyl butyl ether, methyl phenyl ether, dicyclohexyl ether, tert-butyl methyl ether, divinyl ether, 1,2 dimethoxy ethane, ethylene glycol dimethyl ether, furan, 2-methyl furan, tetrahydropyran, and a mixture thereof.

7. The catalyst composition as claimed in claim 1, wherein the zirconium in the zirconium compound and the Lewis base are in a mole ratio in a range of 1:10 to 1:30.

8. A process for preparing a catalyst composition to produce linear alpha olefins by oligomerization of ethylene, the process comprising: mixing a zirconium compound, an organoaluminum compound, at least one Lewis base and an inert organic solvent in a reactor; and forming the catalyst composition in situ in the reactor, wherein the zirconium compound has a formula ZrX.sub.m.nA, wherein X is a halogen atom, m is an integer having a value equal to or less than 4, n is a number equal to or less than 2, and A is selected from the group consisting of tetrahydrofuran, N,N-diisobutylacetamide and a combination thereof, wherein the organoaluminum compound has a formula R.sup.1.sub.nAlY.sub.3-n, or a formula Al.sub.2Y.sub.3R.sup.1.sub.3, wherein R.sup.1 represents an alkyl group having 1 to 20 carbon atoms, Y represents Cl, Br or I, n is a number 1≤n≤2, and wherein the Lewis base is selected from a group consisting of cyclic and acyclic ethers.

9. The process as claimed in claim 8, wherein the inert organic solvent is selected from the group consisting of unsubstituted aromatic hydrocarbons, aromatic hydrocarbons substituted with halogens, aliphatic paraffin hydrocarbons, alicyclic hydrocarbon compounds, halogenated alkanes, and a mixture thereof.

10. A process for producing linear alpha olefins by oligomerization of ethylene in the presence of a catalyst composition, the process comprising: preparing a catalyst composition in a reactor at ambient temperature; charging ethylene into an oligomerization reactor; charging the catalyst composition into the oligomerization reactor under an inert atmosphere at a reaction temperature between 50° C. to 150° C.; and producing about 95 wt. % of linear alpha olefins and traces of polymer by-product, wherein the catalyst composition comprises: a zirconium compound having a formula ZrX.sub.m.nA, wherein X is a halogen atom, m is an integer having a value equal to or less than 4, n is a number equal to or less than 2, and A is selected from the group consisting of tetrahydrofuran, N,N-diisobutylacetamide and a combination thereof; an organoaluminum compound having a formula R.sup.1.sub.nAlY.sub.3-n, or a formula Al.sub.2Y.sub.3R.sup.1.sub.3, wherein R.sup.1 represents an alkyl group having 1 to 20 carbon atoms, Y represents Cl, Br, or I, n is a number 1≤n≤2; and at least one Lewis base, wherein the Lewis base is selected from a group consisting of cyclic and acyclic ethers.

11. The process as claimed in claim 10, wherein the linear alpha olefins have a weight percent distribution of C4-C24 carbon.

12. The process as claimed in claim 10, wherein the linear alpha olefins have greater than 60 wt. % of C6-C10 fraction.

13. The process as claimed in claim 10, wherein the reaction temperature is between 60° C. to 110° C.

14. The process as claimed in claim 10, wherein preparing the catalyst composition in the reactor at ambient temperature comprises: mixing a zirconium compound, an organoaluminum compound, at least one Lewis base and an inert organic solvent in the reactor; and forming the catalyst composition in situ in the reactor,

15. The process as claimed in claim 14, wherein the inert organic solvent is selected from the group consisting of unsubstituted aromatic hydrocarbons, aromatic hydrocarbons substituted with halogens, aliphatic paraffin hydrocarbons, alicyclic hydrocarbon compounds, halogenated alkanes, and a mixture thereof.

16. The process as claimed in claim 15, wherein the substituted aromatic hydrocarbons are selected from the group consisting of toluene, benzene, xylene, chlorobenzene, dichlorobenzene, and chlorotoluene.

17. The process as claimed in claim 15, wherein the aliphatic paraffin hydrocarbons are selected from the group consisting of pentane, hexane, heptane, octane, nonane, and decane.

18. The process as claimed in claim 15, wherein the alicyclic hydrocarbon compounds are cyclohexane, or decahydronaphthalene.

19. The process as claimed in claim 15, wherein the halogenated alkanes are dichloroethane, or dichlorobutane.

20. The process as claimed in claim 10, wherein the inert atmosphere is provided by nitrogen or argon.

Description

EXAMPLE

[0050] Tetrachlorobis(tetrahydrofuran) zirconium was received from Sigma-Aldrich and was used as such. Tetrachlorobis(N,N-diisobutylacetamide)zirconium was prepared as reported in US20210178376.

[0051] Oligomerization of ethylene was performed as follows:

[0052] In a charging flask, equipped with nitrogen, 20 ml of dry toluene was added followed by addition of Zirconium catalyst. This clear homogenous mixture was stirred for 15 minutes and dissolution of the catalyst was observed. Then cocatalyst was added to the solution followed by addition of lewis base as the additive. At this point complete dissolution of catalyst was observed. This clear solution was charged into preconditioned reactor at 30° C. having dry toluene. The oligomerization was conducted at 80° C. and 35 bar ethylene pressure for 60 minutes. After the retrieval of clear liquid, it was treated with 10 ml methanol for quenching the catalyst system. There was no wax formation as well as polymer formation and if polymer was detected, it was only in traces.

[0053] A sample of liquid product was analyzed by gas chromatography (GC-FID) to determine the quantity & distribution of ethylene and higher oligomers.

[0054] The following examples are included herein for illustrative purposes only. Those skilled in the art will appreciate that many modifications may be made in the invention without changing the essence of invention.

Abbreviations

[0055] 1. EASC=ethylene aluminum sesquichloride [0056] 2. DEAC=diethylaluminum chloride [0057] 3. DEE=diethylether [0058] 4. DPE=di-n-propylether [0059] 5. DBE=di-n-butylether [0060] 6. EA=ethyl acetate [0061] 7. DiPE=di-iso-propylether [0062] 8. BPE=butylphenylether [0063] 9. 2MF=2-methyl furan [0064] 10. EG=monoethylene glycol [0065] 11. ZrCl.sub.4.2THF=tetrachlorobis(tetrahydrofuran) zirconium=ZrT [0066] 12. ZrCl.sub.4.2(N, N-diisobutylacetamide)=Tetrachlorobis(N,N-diisobutylacetamide)zirconium=ZrN

[0067] Further, below tables (1-4) depict Ethylene oligomerization using different conditions and details of the conditions is provided in the tables (1-4) as mentioned hereinbelow.

TABLE-US-00001 TABLE 1 Working examples of using different cyclic and acyclic ethers as additives for oligomerization of ethylene using EASC as cocatalyst, Al/Zr (mol) = 17.5 and Zr/additive (mol) = 30 Productivity Distribution of α-olefins (wt %) α-olefins S. No. Catalyst Additive (kg LAO/g Zr) C4 C6-C10 C12-C18 C20+ (wt %) OLM#1 ZrT EA 2.2 32.3 58.2 9.4 0.03 >90 OLM#2 ZrN 3.4 38.7 54.8 6.4 0.1 >96 OLM#3 ZrT/ZrN 3.1 36.3 57.2 6.4 0.1 >92 (1:1 mole ratio) OLM#4 ZrT DEE 14.0 19.8 60.9 19.2 0.1 >96 OLM#5 ZrN 13.0 20.4 61.2 18.2 0.2 >96 OLM#6 ZrT/ZrN 15.0 19.5 62.0 18.4 0.1 >96 (1:1 mole ratio) OLM#7 ZrT DBE 14.3 17.4 64.6 17.9 0.1 >96 OLM#8 ZrN 13.9 19.7 64.9 15.3 0.1 >95 OLM#9 ZrT/ZrN 16.1 17.5 65.1 17.3 0.1 >96 (1:1 mole ratio) OLM#10 ZrT DiPE 13.9 13.9 67.1 18.9 0.1 >97 OLM#11 ZrN 14.3 15.7 66.9 17.3 0.1 >96 OLM#12 ZrT/ZrN 15.0 15.0 67.6 17.3 0.1 >96 (1:1 mole ratio) OLM#13 ZrT BPE 15.0 16.8 65.7 17.4 0.1 >95 OLM#14 ZrN 14.7 18.2 64.9 16.8 0.1 >97 OLM#15 ZrT/ZrN 16.7 16.6 65.8 17.5 0.1 >96 (1:1 mole ratio) OLM#16 ZrT 2MF 13.1 16.7 66.3 16.9 0.1 >96 OLM#17 ZrN 13.2 17.4 65.2 17.3 0.1 >96 OLM#18 ZrT/ZrN 14.0 14.7 67.1 18.1 0.1 >97 (1:1 mole ratio) OLM#19 ZrT EG 14.7 14.5 66.8 18.6 0.1 >96 OLM#20 ZrN 13.9 16.4 67.2 16.3 0.1 >96 OLM#21 ZrT/ZrN 17.0 12.7 68.3 18.9 0.1 >97 (1:1 mole ratio)

TABLE-US-00002 TABLE 2 Working examples of using different cocatalyst for oligomerization of ethylene using DBE as additive, Al/Zr (mol) = 17.5 and Zr/additive (mol) = 30 Productivity Distribution of α-olefins (wt %) α-olefins S. No. Catalyst Cocatalyst (kg LAO/g Zr) C4 C6-C10 C12-C18 C20+ (wt %) OLM#7 ZrT EASC 14.3 17.4 64.6 17.9 0.1 >96 OLM#8 ZrN 13.9 19.7 64.9 15.3 0.1 >95 OLM#9 ZrT/ZrN 16.1 17.5 65.1 17.3 0.1 >96 (1:1 mole ratio) OLM#22 ZrT DEAC 15.6 11.3 67.6 20.9 0.2 >96 OLM#23 ZrN 14.5 12.7 67.9 19.3 0.1 >96 OLM#24 ZrT/ZrN 17.1 11.2 67.4 21.3 0.1 >96 (1:1 mole ratio) OLM#25 ZrT EASC/DEAC 18.6 13.6 65.8 20.5 0.1 >96 OLM#26 ZrN (1:1 mol 17.8 16.2 64.0 19.7 0.1 >96 OLM#27 ZrT/ZrN ratio) 18.7 15.8 64.3 19.8 0.1 >96 (1:1 mole ratio)

TABLE-US-00003 TABLE 3 Working examples of using different mol ratios of alkyl aluminums for oligomerization of ethylene using EASC as cocatayst, DBE as additive and Zr/additive (mol) = 30 Productivity Distribution of α-olefins (wt %) α-olefins S. No. Catalyst Al/Zr (kg LAO/g Zr) C4 C6-C10 C12-C18 C20+ (wt %) OLM#7 ZrT 17.5 14.3 17.4 64.6 17.9 0.1 >96 OLM#8 ZrN 13.9 19.7 64.9 15.3 0.1 >95 OLM#9 ZrT/ZrN 16.1 17.5 65.1 17.3 0.1 >96 (1:1 mole ratio) OLM#28 ZrT 35 17.3 15.6 66.1 18.2 0.1 >96 OLM#29 ZrN 14.9 15.3 65.8 18.8 0.1 >96 OLM#30 ZrT/ZrN 17.5 15.5 65.7 18.7 0.1 >96 (1:1 mole ratio) OLM#31 ZrT 5 0.8 80.2 12.6 7.1 0.1 >75 OLM#32 ZrN 0.2 45.6 34.7 19.6 0.1 >75 OLM#33 ZrT/ZrN 0.6 77.3 13.5 9.1 0.1 >75 (1:1 mole ratio) OLM#34 ZrT 65 18.6 14.9 64.5 20.3 0.3 >95 OLM#35 ZrN 18.9 12.9 65.2 21.5 0.4 >95 OLM#36 ZrT/ZrN 19.1 12.4 65.6 21.5 0.5 >95 (1:1 mole ratio) OLM#37 ZrT 200 No — — — — — OLM#38 ZrN oligomerization — — — — — OLM#39 ZrT/ZrN — — — — — (1:1 mole ratio)

TABLE-US-00004 TABLE 4 Working examples of using different mol ratio of DBE for oligomerization of ethylene using EASC as cocatalyst and Al/Zr mol ratio as 17.5 Zr/Additive Productivity Distribution of α-olefins (wt %) α-olefins S. No. Catalyst mol ratio (kg LAO/g Zr) C4 C6-C10 C12-C18 C20+ (wt %) OLM#7 ZrT 30 14.3 17.4 64.6 17.9 0.1 >96 OLM#8 ZrN 13.9 19.7 64.9 15.3 0.1 >95 OLM#9 ZrT/ZrN 16.1 17.5 65.1 17.3 0.1 >96 (1:1 mole ratio) OLM#40 ZrT 20 14.1 16.2 64.1 19.6 0.1 >96 OLM#41 ZrN 14.2 16.8 63.4 19.7 0.1 >96 OLM#42 ZrT/ZrN 15.2 16.5 64.0 19.4 0.1 >96 (1:1 mole ratio) OLM#43 ZrT 10 13.9 16.2 63.2 20.5 0.1 >96 OLM#44 ZrN 14.1 16.3 64.2 19.4 0.1 >96 OLM#45 ZrT/ZrN 15.0 16.1 64.2 19.6 0.1 >96 (1:1 mole ratio)