Catalyst and process for ethylene oligomerization
US6184428A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1999 |
| Grant date | Feb 6, 2001 |
| Priority date | — |
| Expiry date | Feb 17, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/52
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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.sub.2.6H.sub.2 O); (3) a catalyst activator, preferably sodium tetraphenylborate (NaBPh.sub.4); and (4) silica. A 1:1:1 molar ratio of Ni:DPPBA:BPh.sub.4 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.degree. C., respectively, for about two hours. The oligomer product formed has a narrower weight percent distribution, typically having about 96 weight percent C.sub.4 's to C.sub.10 's, compared to product formed using a homogeneous catalyst system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.