The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 06, 2001
Filed:
Feb. 17, 1999
Mohammad Akhtar Zahoor, Riyadh, SA;
Fahad Al-Sherehy, Riyadh, SA;
Olagoke Olabisi, Houston, TX (US);
Mohammed M. Abdillahi, Dhahran, SA;
Mian Rahat Saeed, Dhahran, SA;
Abstract
A catalyst and a process are provided for oligomerizing ethylene. A heterogeneous catalyst system comprises: (1) a chelating ligand, preferably 2-diphenyl phosphino benzoic acid (DPPBA); (2) a nickel precursor, preferably nickel chloride hexahydrate (NiCl,.6H,O); (3) a catalyst activator, preferably sodium tetraphenylborate (NaBPh,); and (4) silica. A 1:1:1 molar ratio of Ni:DPPBA:BPh,catalyst components are fixed on a silica support using low-temperature fixation. The catalyst components are dispersed in a diluent, preferably ethanol, and silica is added. The ethanol is evaporated using freeze-drying equipment to form a silica-supported catalyst system. The silica-supported catalyst is slurried in ethanol in a reactor, and ethylene is added. The reactor pressure and temperature are maintained at about 725 psig and 100° C., respectively, for about two hours. The oligomer product formed has a narrower weight percent distribution, typically having about 96 weight percent C,'s to C,'s, compared to product formed using a homogeneous catalyst system.