Sasol Technology Proprietary Limited

University of Cape Town

Sasol Technology (pty) Limited

Engelhard De Meern B.v.

Sasol South Africa Limited

Jan Van De Loosdrecht

Peter Jacobus Van Berge

Jacobus Lucas Visagie

Jan Mattheus Botha

Sean Barradas

Abdool Muthalib Saib

Michael Steven Datt

Hendrik Van Rensburg

Elsie Adriana Caricato

Jacobus Lucus Visagie

Johannes Gerhardus Koortzen

Alta Bohmer

Michael Christian Maximilian Claeys

Eric Wilhelmus Josephus Van Steen

Willem Adriaan Booysen

Hans Marcel Veltman

Denzil James Moodley

Jana Heloise Potgieter

Cornelia Carolina Eloff

Tjaart Jurgens Van Der Walt

Johan Coenraad Sollie

Sylvia Sollie-Breur, Legal Representative

Prabashini Moodley

Bulelani Humphrey Sigwebela

The present invention relates to catalysts, more particularly to a cobalt-containing catalyst composition. The present invention further relates to a process for preparing a cobalt-containing catalyst precursor, a process for preparing a cobalt-containing catalyst, and a hydrocarbon synthesis process wherein such a catalyst is used. According to a first aspect of the invention, there is provided a cobalt-containing catalyst composition comprising cobalt and/or a cobalt compound supported on and/or in a silica (SiO) catalyst support wherein the average pore diameter of the catalyst support is more than 20 nm but less than 50 nm; the catalyst composition also including a titanium compound on and/or in the catalyst support, and a manganese compound on and/or in the catalyst support.

Cobalt-containing catalyst composition

A process for preparing a cobalt-containing hydrocarbon synthesis catalyst precursor includes calcining a loaded catalyst support comprising a catalyst support supporting a cobalt compound. The calcination includes subjecting the loaded catalyst support to heat treatment by heating the loaded catalyst support to a temperature, T, of at least 220&#xb0; C. at a heating rate below 10&#xb0; C./minute, and effecting gas flow at a space velocity of at least 9 mn/kg cobalt compound/hour over the loaded catalyst support during at least part of the heating. The cobalt-containing hydrocarbon synthesis catalyst precursor is thereby produced.

Process for preparing a cobalt&#x2014;containing hydrocarbon synthesis catalyst precursor

A process for regenerating a spent cobalt Fischer-Tropsch synthesis catalyst includes subjecting a spent particulate cobalt Fischer-Tropsch synthesis catalyst sequentially to a dewaxing treatment, an oxidation treatment at a pressure of 4 to 30 bar(a) and a reduction treatment, thereby regenerating the catalyst.

Catalysts

A magnetometer which includes an elongate reactor in which a sample can be secured in a sample support zone and which is located within a magnetic field space of a magnetic field generator and one or more signal pickup coils. Movement generating means is provided for generating relative movement in a generally linear direction between the reactor and at least one of the magnetic field and pickup coil, preferably by moving the reactor in its length. The magnetometer is characterised in that the reactor is a metal tube having a length which permits its ends to remain external of the signal pickup device during the relative movement.

Magnetometer

A process for regenerating a spent particulate wax-containing cobalt-based Fischer-Tropsch synthesis catalyst is provided. The process includes subjecting the spent wax-containing catalyst sequentially to a dewaxing treatment, an oxidation treatment and a reduction treatment. During the dewaxing treatment, the spent wax-containing catalyst is at least partially dewaxed, with dewaxed catalyst particles being produced. During the oxidation treatment, an oxygen-containing gas is passed through a bed of the dewaxed catalyst particles at an operating temperature T&#xb0; C. where 150&#x3c;T&#x3c;450, and the operating temperature is controlled by removing heat from the catalyst particle bed using a cooling device, to obtain oxidized catalyst particles. During the reduction treatment, the oxidized catalyst particles are reduced, thereby regenerating the catalyst.

A process for preparing a cobalt based Fischer-Tropsch synthesis catalyst precursor includes introducing a multi-functional carboxylic acid having the general formula (1) HOOC&#x2014;C*RC*R&#x2014;COOH (1) or a precursor thereof, where C* in each of C*Ri and C*R2 is a spcarbon, and Rand Rare the same or different, and are each selected from the group consisting of hydrogen and an organic group, into and/or onto a particulate catalyst support. The ratio of the quantity of multifunctional carboxylic acid used relative to the support surface area is at least 0.3 &#x3bc;mol carboxylic acid/mof support surface area. Simultaneously with the introduction of the carboxylic acid into and/or onto the catalyst support, or subsequent thereto, a cobalt compound is introduced into and/or onto the catalyst support. The impregnated support is calcined to obtain the cobalt based Fischer-Tropsch synthesis catalyst precursor.

A process for producing a supported cobalt-based Fischer-Tropsch synthesis catalyst includes, in a first activation stage, treating a particulate catalyst precursor with a reducing gas, at a heating rate, HR1, until the precursor has reached a temperature, T, where 80&#xb0; C.&#x2266;T&#x2266;180&#xb0; C., to obtain a partially treated precursor. In a second activation stage, the partially treated precursor is treated with a reducing gas, at an average heating rate, HR2, with x step increments, where 0&#x3c;HR2&#x3c;HR1, for a time, t, where tis from 0.1 to 20 hours, to obtain a partially reduced precursor. Thereafter, in a third activation stage, the partially reduced precursor is treated with a reducing gas, at a heating rate, HR3, where HR3&#x3e;HR2 until the partially reduced precursor reaches a temperature, T. The partially reduced precursor is maintained at Tfor a time, t, where tis from 0 to 20 hours, to obtain an activated catalyst.

A process for producing a supported cobalt-based Fischer-Tropsch synthesis catalyst includes, in a first activation stage, treating a particulate catalyst precursor with a reducing gas, at a heating rate, HR1, until the precursor has reached a temperature, T, where 80&#xb0; C.&#x2266;T&#x2266;180&#xb0; C., to obtain a partially treated precursor. In a second activation stage, the partially treated precursor is treated with a reducing gas, at a heating rate, HR2, where 0&#x2266;HR2&#x3c;HR1, for a time, t, where tis from 0.1 to 20 hours, to obtain a partially reduced precursor. Thereafter, in a third activation stage, the partially reduced precursor is treated with a reducing gas, at a heating rate, HR3, where HR3&#x3e;HR2 until the partially reduced precursor reaches a temperature, T. The partially reduced precursor is maintained at Tfor a time, t, where tis from 0 to 20 hours, to obtain an activated catalyst.

A particulate pre-reduction cobalt supported Fischer-Tropsch synthesis catalyst precursor which comprises a catalyst support impregnated with cobalt, is treated with a pure hydrogen reducing gas, at a first specific feed gas space velocity, SV1, and at a first heating rate, HR1, to obtain a partially reduced precursor. The support contains reducible cobalt oxide in a calcined state and having a formula-unit in which each mole of cobalt atoms is associated with more than 4/3 moles of oxygen atoms and displaying a reducible cobalt oxide specific surface area at least equal to that of CoOspinel. The partially reduced precursor is then treated with a pure hydrogen reducing gas, at a second specific feed gas space velocity, SV2, and at a second heating rate, HR2, to obtain an activated supported Fischer-Tropsch catalyst, with SV2&#x2266;SV1 and/or HR2&#x2267;HR1; however, when SV2=SV1, HR2&#x2260;HR1 and when HR2=HR1, SV2&#x2260;SV1.

Process for activating cobalt catalysts

A process for preparing a cobalt based catalyst precursor includes in a first support impregnation/drying/calcination stage, impregnating a particulate porous catalyst support with a cobalt salt, partially drying the impregnated support, and calcining the partially dried impregnated support to obtain a calcined material. The calcined material is partially reduced. Thereafter, in a second support impregnation/drying/calcination stage, the partially reduced material is impregnated with a cobalt salt, partially dried and calcined, to obtain the cobalt based catalyst precursor.

Cobalt catalysts

A process for preparing and using a cobalt slurry phase Fischer-Tropsch synthesis catalyst includes introducing a modifying component Mc into a catalyst support precursor, followed by shaping and calcination, to obtain a catalyst support. The catalyst support is impregnated with an aqueous solution of a cobalt salt, to form an impregnated support which is partially dried and calcined, to obtain a catalyst precursor. The catalyst precursor is reduced to form a cobalt slurry phase Fischer-Tropsch synthesis catalyst. A synthesis gas is contacted with this catalyst in a slurry phase Fischer-Tropsch synthesis reaction at elevated temperature and elevated pressure, and a clean wax product that contains less than 50 mass ppm submicron particulates of cobalt is obtained.

Production of fischer-tropsch synthesis produced wax

A process for preparing a cobalt based catalyst precursor includes, in a support impregnation stage, impregnating a coated catalyst support comprising porous catalyst support particles coated with carbon, with a cobalt salt, and partially drying the impregnated support. Thereafter, in a calcination stage, the partially dried impregnated support is calcined, to obtain the cobalt based catalyst precursor. The cobalt based catalyst precursor can then, in a reduction stage, be reduced to obtain a cobalt based Fischer-Tropsch catalyst.

A method of treating an untreated catalyst support includes contacting an untreated catalyst support which is partially soluble in an aqueous acid and/or a neutral aqueous solution with a modifying component precursor of the formula Me(OR)where Me is a modifying component selected from Si, Zr, Ti, Cu, Zn, Mn, Ba, Co, Ni, Na, K, Ca, Sn, Cr, Fe, Li, TI, Mg, Sr, Ga, Sb, V, Hf, Th, Ce, Ge, U, Nb, Ta, and W, R is an alkyl or acyl group, and x is an integer having a value of from 1 to 5. The modifying component is thereby introduced onto and/or into the catalyst support to form a protected modified catalyst support which is less soluble in the aqueous acid and/or the neutral aqueous solution. No calcination of the protected modified catalyst support is effected.

Method of treating an untreated catalyst support, and forming a catalyst precursor and catalyst from the treated support

A cobalt based Fischer-Tropsch catalyst which including a porous catalyst support and metallic cobalt crystallites within the support. The catalyst has a proportion of its cobalt in reducible form, with this proportion being expressible as &OHgr; mass %, based on the total pre-reduction catalyst mass. The catalyst also has, when freshly reduced, a mono-modal Gaussian metallic cobalt crystallite size distribution, a metallic cobalt surface area, in m per gram of catalyst, of from 0.14 &OHgr; to 1.03 &OHgr;, and a catalyst geometry that ensures a stabilized Fischer-Tropsch synthesis effectiveness factor of 0.9 or greater.

A cobalt catalyst precursor includes a catalyst support impregnated with cobalt. All reducible cobalt is present in the support as supported cobalt oxide of formula-unit CoOaHb, where a&gE;1,7 and b&gE;0. A process for preparing a cobalt catalyst precursor, and a process for preparing a cobalt catalyst are also provided.

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Sasolburg, South Africa

Jan Van De Loosdrecht