Process for synthesizing 1-butene by dimerization of ethylene

• US 4,532,370 A
• Filed: 09/20/1984
• Issued: 07/30/1985
• Est. Priority Date: 09/20/1983
• Status: Expired due to Term

• Current Assignee: Institut Francais Du Petrole
• Original Assignee: Institut Francais Du Petrole
• Inventors: Chauvin, Yves, Commereuc, Dominique, Leger, Gerard, Cruypelinck, Daniel, Le Quan, Nhuong
• Primary Examiner(s): Gantz, D. E.
• Assistant Examiner(s): Pal, A.
• Application Number:
  US06/652,555
• Time in Patent Office: 313 Days
• Field of Search: 585/510, 585/512, 585/524
• US Class Current: 585/512
• CPC Class Codes: B01J 2531/46 Titanium
• CPC Class Codes: B01J 31/0212 Alkoxylates
• CPC Class Codes: B01J 31/143 of aluminium
• CPC Class Codes: B01J 31/2208 Oxygen, e.g. acetylacetonates
• CPC Class Codes: C07C 11/08 with four carbon atoms
• CPC Class Codes: C07C 2/30 containing metal-to-carbon bond; Metal hydrides
• CPC Class Codes: C07C 2531/02 containing organic compounds or metal hydrides
• CPC Class Codes: C07C 2531/12 containing organo-metallic compounds or metal hydrides
• CPC Class Codes: C07C 2531/14 of aluminium or boron

Abstract

Process for synthesizing 1-butene by dimerization of ethylene, in the presence of a catalyst formed by reacting, in a hydrocarbon medium, a trialkylaluminum with a mixture of an alkyl titanate with an ether. The activity and the selectivity are improved when adding the ether to a pre-formed mixture of alkyl titanate with trialkylaluminum.

Claims

1. An improved process for converting ethylene to 1-butene wherein ethylene is contacted with a catalyst obtained by reacting an alkyl titanate with an alkylaluminum compound, characterized in that said catalyst results from reacting a preformed mixture of alkyl titanate and ether, in a molar ratio ether/titanate from 0.5:

1 to 10;

1, with an aluminum compound of formula AIR₃ or AIR₂ H, wherein each R is a hydrocarbyl radical.

2. A process according to claim 1, wherein the molar ratio of the ether to the alkyl titanate is from about 1:

1 to 3;

1.

3. A process according to claim 1, wherein said reaction is performed in a solvent consisting of hexenes recovered as by-products of the reaction.

4. A process according to claim 1, wherein the ether is diethylether, isopropylether, dibutylether, methyltert-butylether, tetrahydrofuran, 1,4-dioxane, dihydropyran or ethyleneglycol dimethylether.

5. A process according to claim 4, wherein the ether is 1,4-dioxane.

6. A process according to claim 4, wherein the ether is tetrahydrofuran.

7. A process according to claim 1, wherein the reaction of the preformed mixture of alkyl titanate and ether with the aluminum compound is performed at a temperature from -10°

to +45°

C. in ethylene atmosphere and the temperature is then increased to 50°

-70°

C. to convert ethylene to 1-butene.

8. A process according to claim 7, wherein the admixed catalyst components are maintained at a temperature from -10°

to +45°

C. for 30 seconds to 24 hours before increasing the temperature to 50°

-70°

C.

9. A process according to claim 1, wherein the molar ratio of the aluminum compound to the titanium compound is from 1:

1 to 20;

1 and the titanium concentration is from 10^-4 to 0.5 mole per liter when the catalyst is used for converting ethylene to 1-butene at a temperature from 20°

to 150°

C. under a pressure from 0.5 to 8 MPa.

10. A process according to claim 9 wherein the temperature is from 20°

to 70°

C.