Sasol Technology Proprietary Limited

Sasol Technology (Pty) Limited

Stephen John Evans

Kevin Blann

Martin John Hanton

David Matthew Smith

William Fullard Gabrielli

Sean W Ewart

John Thomas Dixon

Matthew James Overett

David Hedley Morgan

Denise Louisette Venter

Tyrone McKnight

Henriette De Bod

Brian William Stirling Kolthammer

Natasha Brigman

Elzet Grobler

Brian William Kolthammer

Sean William Ewart

Tyrone Mcknight

A process for the tetramerisation of ethylene under solution phase conditions is carried out in the presence of an activated catalyst at a temperature above 80&#xb0; C. and up to a temperature of about 115&#xb0; C. The activated catalyst is provided by combining a source of chromium, a diphosphine ligating compound and optionally a catalyst activator or combination of catalyst activators. The process forms at least 30% 1-octene and a polyethylene co-product that, together with any other reaction products, remains substantially dissolved in the liquid phase. The polyethylene co-product has a weight average molecular weight (Mw) of less than 200 000 g/mol, a number average molecular weight (Mn) of less than 3 000 g/mol, and a melt flow index of more than 20 g/10 minutes.

Tetramerisation of ethylene

A process for oligomerization of an olefinic compound for producing an oligomeric product is carried out in the presence of an activated catalyst, a non-metal oxygen containing additive and optionally a zinc compound. The oligomerization catalyst is an activated catalyst, which is provided by combining a source of chromium, a ligating compound, and a catalyst activator or combination of catalyst activators. The non-metal oxygen containing additive is present in an amount such that the ratio of the molar amount of the non-metal oxygen containing additive to the molar amount of chromium in the source of chromium per 10g/g Cr productivity is between 0.01 and 400.

Oligomerisation of olefinic compounds with reduced polymer formation

A process () to separate a multi-component hydrocarbon stream () comprising ethylene, at least one polymer and other components includes flashing the multi-component hydrocarbon stream in a first flash stage () from an elevated pressure of more than 30 bar(a) and an elevated temperature in the range of 150&#xb0; C. to 135&#xb0; C. to a flash pressure in the range of 10 bar(a) to 30 bar(a), producing a first ethylene-containing vapor overheads product () at a pressure in the range of 10 bar(a) to 30 bar(a) and a first flash stage bottoms product () which includes some ethylene, the at least one polymer and some of the other components. The flash pressure and the elevated temperature of the multi-component hydrocarbon stream () are selected such that the first flash stage bottoms product () has a concentration of the at least one polymer of less than 5% by mass to render the viscosity of the first flash stage bottoms product () at the temperature of the first flash stage bottoms product () in the first flash stage () at less than 1000 cP at a shear of 1 per second. At least a portion of the first flash stage bottoms product () is heated to a temperature in excess of 150&#xb0; C. to form a heated first flash stage bottoms product (). A recycle portion () of the heated first flash stage bottoms product () is combined with the multi-component hydrocarbon stream (), which is at a temperature less than 150&#xb0; C. before combination with the recycle portion (), thereby to heat the multi-component hydrocarbon stream () to the elevated temperature in the range of 150&#xb0; C. to 185&#xb0; C. At least a portion () of the first flash stage bottoms product and the first ethylene-containing vapor overheads product () are withdrawn from the first flash stage ().

Separation of components from a multi-component hydrocarbon stream

This invention relates to the oligomerization of olefinic compounds in the presence of an activated oligomerization catalyst. The invention also extends to a particular manner for providing an activated oligomerization catalyst. According to the present invention, there is provided a process for producing an oligomeric product by the oligomerization of at least one olefinic compound, the process including (a) providing an activated oligomerization catalyst by combining, in any order, iii) a source of chromium, &#x3b9;v) a ligating compound of the formula (R)mX(Y)X(R)n wherein Xand Xare independently an atom selected from the group consisting of nitrogen, phosphorus, arsenic, antimony, bismuth, oxygen, sulphur and selenium or said atom oxidized by S, Se, N or O where the valence of Xand/or Xallows for such oxidation, Y is a linking group between Xand Xwhich linking group contains at least one nitrogen atom which is directly bonded to Xor X, m and n are independently 0, 1 or a larger integer, and Rand Rare independently hydrogen, a hydrocarbyl group, an organoheteryl group or a heterohydrocarbyl group, and the respective Rgroups are the same or different when m&#x3e;1, and the respective Rgroups are the same or different when n&#x3e;1, in) a catalyst activator which is an organoboron compound including a cation and a non-coordinating anion of the general formula [(R)xL*-H]+[B(R)4]wherein L* is an atom selected from the group consisting of N, S and P, the cation [(R)x L*-H]* is a Bronsted acid, x is an integer 1, 2 or 3, each Ris the same or different when x is 2 or 3 and each is a &#x2014;H, hydrocarbyl group or a heterohydrocarbyl group, provided that at least one of Rcomprises at least 6 carbon atoms and provided further that the total number of carbon atoms in (R)x collectively is greater than 12, Rindependently at each occurrence is selected from the group consisting of hydride, dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, halosubstituted-hydrocarbyl radicals, halosubstituted-alkoxide, halosubstituted-aryloxide and a halosubstituted aromatic ring moiety with at least one halide substituent on the aromatic ring, and vi) an aliphatic solvent, and (b) contacting the at least one olefinic compound with the activated oligomerization catalyst to produce an oligomeric product.

Oligomerisation of olefinic compounds in the presence of an activated oligomerisation catalyst

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Roodepoort, South Africa

Stephen John Evans