Catalyst support

Abstract

A packing member for use in a packed bed, preferably a support for use as a catalyst support in a packed bed reactor. The packing member includes ceramic material and has a geometric surface area per volume of ?0.7 cm.sup.2/cm.sup.3 and a side crush strength of ?250 kgf; or a geometric surface area per volume of ?1.5 cm.sup.2/cm.sup.3 and a side crush strength of ?150 kgf; or a geometric surface area per volume of ?3 cm.sup.2/cm.sup.3 and a side crush strength of ?60 kgf. The packing member optionally has a porosity of at least 6%, such as at least 15% or at least 20%.

Claims

1. A packing member for use in a packed bed comprising a ceramic material and wherein the packing member has: a geometric surface area per volume of ?0.7 cm.sup.2/cm.sup.3 and a side crush strength of ?5.7 kg/mm; wherein the packing member optionally has a porosity of at least 6%, and wherein the packing member has a macrostructure and comprises surface structures on the outer face of the macrostructure, wherein the packing member comprises surface structures extending over at least 60% of the outer face of the macrostructure.

2. The packing member according to claim 1, wherein the packing member is a cast packing member formed from a moulding composition comprising an organic binder component, a ceramic material, optionally a pore forming component, optionally a polymerisation initiator, and optionally a polymerisation accelerator.

3. The packing member according to claim 1, wherein the packing member is gel cast from a composition comprising a ceramic material, an organic binder component, optionally a pore forming component, optionally a polymerisation initiator, and optionally a polymerisation accelerator.

4. The packing member according to claim 1, wherein the packing member has a geometric surface area per volume (GSA) of ?1 cm.sup.2/cm.sup.3, with a side crush strength of ?8.3 kg/mm.

5. The packing member according to claim 1, wherein the packing member has a GSA of ?1.7 cm.sup.2/cm.sup.3.

6. The packing member according to claim 1, wherein the packing member has a porosity of ?15%.

7. The packing member according to claim 1, wherein the macrostructure of the packing member is in the form of a cog and at least some of the castellations of the cog are tapered along the depth and/or the width of the castellations, and/or the macrostructure has a depressed upper and/or lower face.

8. The packing member according to claim 1, wherein the surface structures are in the form of ridges and/or mounds.

9. The packing member according to claim 2, wherein the organic binder component comprises a polymerisable monomer and a crosslinking member.

10. The packing member according to claim 9, wherein the polymerisable monomer comprises one or more type of ethylenically unsaturated monomers.

11. The packing member according to claim 9, wherein the polymerisable monomer comprises one or more acrylamide monomers.

12. The packing member according to claim 9, wherein the crosslinking member is selected from one or more of a diethylenically unsaturated monomer.

13. The packing member according to claim 9, wherein the crosslinking member is selected from one or more of poly(ethylene glycol) dimethacrylate (PEGDMA), N,N-methylenebis(acrylamide) (BIS), ammonium acrylate and PEG methylethylmethacrylate (PEGMEM).

14. The packing member according to claim 9, wherein the organic binder component comprises from 40 to 95 wt % of a polymerisable monomer and from 60 to 5 wt % of a crosslinking member.

15. The packing member according to claim 2, wherein the composition comprises a pore forming material having a particle size distribution wherein D10 is from 5 to 100 ?m, and/or the D50 of the pore forming material is from 50 to 200 ?m, and/or the D90 of the pore forming material is from 120 to 300 ?m.

16. The packing member according to claim 1, wherein the ceramic material comprises aluminium oxide, aluminium silicate, magnesium aluminate, calcium aluminate, zirconia, silica, titanate, carbon and/or magnesium oxide.

17. The packing member according to claim 1, wherein the ceramic material has a particle size distribution wherein D10 is from 0.1 to 20 ?m, and/or the D50 is from 0.5 to 30 ?m, and/or the D90 is from 10 to 100 ?m.

18. The packing member according to claim 1, wherein the packing member comprises a promoter selected from one or more oxides of lanthanum, copper, magnesium, manganese, potassium, calcium, zirconium, barium, cerium, sodium, lithium, molybdenum, yttrium, cobalt, and chromium.

19. The packing member according to claim 1, wherein the packing member comprises a dispersant.

20. The packing member according to claim 2, wherein the composition comprises from 0.1 to 10% of polymerisable monomer by dry weight of the composition.

21. The packing member according to claim 2, wherein the composition comprises from 0.1 to 10% of crosslinking member by dry weight of the composition.

22. The packing member according to claim 2, wherein the composition comprises from 50 to 95% of ceramic material by dry weight of the composition.

23. The packing member according to claim 2, wherein the composition comprises from >0 to 40% of pore forming member by dry weight of the composition.

24. The packing member according to claim 2, wherein the composition comprises from 0.1 to 5% of polymerisation initiator by dry weight of the composition.

25. The packing member according to claim 2, wherein the composition comprises up to 5% of polymerisation accelerator by dry weight of the composition.

26. The packing member according to claim 2, wherein the composition comprises from 0.1 to 10% of dispersant by dry weight of the composition.

27. A supported catalyst comprises the packing member according to claim 1 and a catalytic material comprising a metal selected from one or more of a transition metal, a transition metal oxide, and/or a noble metal or an alloy thereof.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1a, 1b, and 1c show perspective views of two supported catalysts and one inert packing member that are not according to the present invention.

(2) FIGS. 2a and 2b show a top view and a perspective view, respectively, of a first embodiment of catalyst support according to the present invention.

(3) FIG. 3 shows a perspective view of a second embodiment of a catalyst support according to the present invention.

(4) FIGS. 4a and 4b show perspective views of a first embodiment of a supported catalyst according to the present invention.

(5) FIG. 5 shows a perspective view of a second embodiment of a supported catalyst according to the present invention.

(6) FIG. 6 shows a perspective view of a first embodiment of an inert packing member according to the present invention.

(7) FIGS. 7a and 7b show a side and perspective view, respectively, of a fourth embodiment of a supported catalyst according to the present invention.

DETAILED DESCRIPTION

(8) FIG. 1a shows high activity supported catalyst 102 for DRI production not according to the present invention having a cylindrical cog macrostructure with no surface structures and having a plurality of bores 104 extending through the longitudinal length of the support and a plurality of spaced longitudinally orientated castellations 106 that project radially outwards from the support.

(9) FIG. 1b shows a semi-active supported catalyst 202 for DRI production not according to the present invention having the same shape as support catalyst 102 with the exception that supported catalyst 202 has only one longitudinally extending bore 204, which is a central bore, and is approximately twice the height of support catalyst 102.

(10) FIG. 1c shows an inert packing member 302 not according to the present invention having a cylindrical macrostructure with no surface structures and having a single central longitudinal extending bore 304.

(11) FIGS. 2(a) and (b) show a support 402 according to a first embodiment of the present invention having a spherical macrostructure with four equally spaced parallel bores 404 extending between opposite sides of the support. The support 402 further has four equally spaced parallel hemispherical troughs 406 on the outer face of the support. The troughs each have a radius of 2 mm. The outer face of the support 402 has a plurality of interconnected hexagon-shaped ridged surface structures 408 extending over substantially the whole of the outer face. The inner width B of the hexagon shaped ridge is 5.21 mm and inner the length A of each side is 2.61 mm. The portion of the surface structure that extends between the inner edges of ridges 410 is formed of an open ended inverted hexagonal pyramid. The depth of each surface structure is 2 mm.

(12) FIG. 3 shows a support 502 according to the present invention also having a spherical macrostructure. Support 502 also has four equally spaced parallel bores 504 extending between opposite sides of the support and four equally spaced parallel hemispherical grooves 506 on the outer face of the support 502 each having a radius of 2 mm. The surface structures of support 502 are in the form of a two portions having a plurality of interconnected hexagon-shaped ridges 508 extending across opposite sides of the support 502. The inner width D of the hexagon shaped ridges are 6.93 mm and inner the length C of each side is 3.46 mm. Connecting these portions of hexagonal surface structures are further surface structures in the form of a plurality of substantially evenly spaced parallel ridges 510. The portion 512 of the surface structure that extends between the ridges 508 is substantially flat, except for the curvature of the macrostructure of the support.

(13) FIGS. 4a to 4b show a high activity supported catalyst 602 for DRI production according to the present invention. Supported catalyst 602 has a similar macrostructure to comparative supported catalyst 102 in that the supported catalyst 602 has a macrostructure having a cylindrical cog shape with a plurality of bores (5 in total) extending through the longitudinal length of the support and a plurality of spaced longitudinally orientated castellations (10 in total) that project radially outwards from the support. The macrostructure of supported catalyst 602 differs from that of 102 because the macrostructure of support catalyst 602 further has a depression 604 in the upper face of the support 602. Furthermore, each of the castellations of the cog are tapered in depth such that the supported catalyst 602 has a largest outer width F at the base (38.0 mm) to a smallest outer width E at the upper face of supported catalyst 602 (35.1 mm). Each castellation is further tapered in width, from a widest point at the base of supported catalyst 602 to a narrowest width at the upper face of supported catalyst 602.

(14) Unlike supported catalyst 102, which has a substantially smooth outer face with no surface structures, support catalyst 602 has surface structures extending over substantially the whole outer face of the supported catalyst 602. The surface structures are generally in the form of interconnected hexagon-shaped ridges 606 in which the portions 608 of the surface structures extending between the ridges are substantially flat.

(15) FIG. 5 shows a semi-active supported catalyst 702 for DRI production according to the present invention. Supported catalyst 702 has the same macrostructure as support 402 but has different surface structures. The surface structures of supported catalyst 702 are in the form of a plurality of overlapping stepped mounds 704 extending across substantially the whole outer face of the supported catalyst 702.

(16) FIG. 6 shows an inert packing member 802 according to the present invention that has the same macrostructure and surface structures as supported catalyst 702 except that member 802 has a smooth outer surface with no surface structures.

(17) FIGS. 7a and 7b show a further embodiment of a supported catalyst 902. Catalyst 902 has a cylindrical macrostructure with four equally spaced parallel bores 908 extending longitudinally from opposite sides of supported catalyst 902 and four equally spaced grooves 904 on the outer face of the supported catalyst 902. Each groove is tapered along the width from a largest width at the upper face of the catalyst to a narrowest width at the bottom face of the catalyst. Catalyst 902 has a plurality of upwardly projecting hexagonal pyramid shaped surface structure mounds 906. Surface structures 906 extend over substantially all of the side and bottom faces of supported catalyst 902 apart from the base and side faces of grooves 904. The top face of catalyst 902 has no surface structures.

(18) To produce supports, supported catalysts and inert packing member according to the invention, a reactor was modelled using 3D modelling to produce a digital model of the optimum macrostructure and surface features to provide high geometric surface area in combination with excellent packing characteristics and low pressure drop.

(19) A precursor for a mould operable to produce the designed packing member was then produced using additive manufacturing with a 3D printer.

(20) The printed precursor was then used to produce a mould for casting the designed packing member. The mould was arranged on the moulding apparatus and a moulding composition prepared and moulded. The resultant green body was calcined before dipping in a solution comprising the catalytic material.

Supported Catalyst Example 1

(21) Supported catalyst example 1 according to the present invention was produced from a moulding composition formed by mixing the components provided below using the following method.

(22) The alumina powder, pore former and dispersant were mixed to form a powder mixture. An aqueous monomer solution containing the chain forming monomer, the chain linking monomer and the water was added to the powder mixture to form an aqueous slurry. The catalyst and initiator were then added to the aqueous slurry. The amounts of each component in the resulting slurry were:

(23) TABLE-US-00001 Amount Alumina powder 475 Pore former 60 g Dispersant 12.25 g Polymerisable monomer 16.3 g Crosslinking member 8.2 Catalyst 3 ml Initiator 8 ml Water 135 g

(24) The resulting aqueous slurry was then cast into the mould. Once the slurry had gelled into a solid green body after 4-5 mins it was then demoulded. At this point the green body support had a rubbery, jelly-like consistency. The green body was then left to dry at room temperature for 24 hours. The dried green body was then fired to 1450? C., at which point the binder and pore formers were burnt off to leave a solid, porous, supported catalyst.

(25) The support was then dipped in an aqueous solution containing catalytic material Ni(NO.sub.3).sup.2 before drying at 500? C. This catalytic material impregnation step was repeated two more times to produce the final supported catalyst.

(26) Supported catalyst example 1 had a macrostructure and surface structure according to supported catalyst 602 as shown in FIG. 4. Supported catalyst 1 was a high activity catalyst for DRI production due to having a higher concentration of catalytic material on the support then the other example catalysts which was achieved by repeated dipping of the support into the aqueous solution of the catalytic material.

Supported Catalyst Example 2

(27) Supported catalyst example 2 was produced from the same composition and method as used for supported catalyst example 1 with the exception that the impregnation step was only carried out twice. Supported catalyst example 2 had a macrostructure and surface structure according to supported catalyst 702 as shown in FIG. 5. Supported catalyst example 2 was a semi-active catalyst for DRI production.

Inert Packing Member Example 1

(28) Inert packing member example 1 was produced from the same composition and method as used for supported catalyst example 2 with the exception that no pore formers were used and the packing member was not dipped into the solution of catalytic material. Inert packing member example 1 also has a smooth outer surface with no surface structures. Supported catalyst 3 was therefore used as an inert packing member for DRI production.

Catalyst Bed Example 1

(29) Fractions of supported catalyst examples 1 to 2 and inert packing member example 1 were combined in layers to produce catalyst bed example 1. The properties of each layer is provided in Table 1.

(30) TABLE-US-00002 TABLE 1 Catalyst bed example 1 Pressure Packing Number drop (Pa, Side Catalyst height of GSA 453 m.sup.3/hr Voidage crush Ex. activity (m) pellets (cm.sup.2/cm.sup.3) flow) (%) (kgf) Porosity SC Ex. 1 High* 4.0 9,352 2.420 10,240 45.1 100% 30% >220 SC Ex. 2 Semi- 3.0 4,365 1.78 6,000 39.2 100% 30% active** >300 IPM Inert*** 1.0 1,455 1.63 2,000 39.1 100% 10% Ex. 1 >300 Total 8.0 15,172 1.94 18,240 41.1 100% >220 *OW of 35.1 mm, OD2 of 38.0 mm **OD1 of 33 mm, weight of 27 g. ***OD1 of 33 mm weight of 27 g.

Comparative Supported Catalyst Example 1

(31) Comparative supported catalyst example 1 was produced from an alumina based ceramic composition and formed using pelleting. Comparative supported catalyst example 1 had a macrostructure and surface structure according to comparative supported catalyst 102 as shown in FIG. 1a. Supported catalyst example 1 was a high activity catalyst for DRI production.

Comparative Supported Catalyst Example 2

(32) Comparative supported catalyst example 2 was produced from the same composition using the same method as comparative supported catalyst example 1.

(33) Comparative supported catalyst example 2 had a macrostructure and surface structure according to comparative supported catalyst 202 as shown in Figure ib. Supported catalyst example 2 was a semi-active catalyst for DRI production.

Comparative Inert Packing Member Example 1

(34) Comparative inert packing member example 1 was produced from the same composition using the same method as comparative supported catalyst example 1 with the exception that inert packing member example 1 was not impregnated with catalytic material. Inert packing member example 1 had a macrostructure and surface structure according to comparative supported catalyst 302 as shown in FIG. 1c. Supported catalyst example 3 was an inert packing member for DRI production.

Comparative Catalyst Bed Example 1

(35) Fractions of comparative supported catalyst examples 1 to 2 and comparative inert packing member example 1 were combined in layers to produce comparative catalyst bed example 2. The properties of each layer s provided in Table 2.

(36) TABLE-US-00003 TABLE 2 Comparative catalyst bed example 1 Pressure Packing Number drop (Pa, Side C. height of GSA 453 m.sup.3/hr Voidage crush Porosity Ex. Activity (m) pellets (cm.sup.2/cm.sup.3) flow) (%) (kgf) (%) C. SC High* 4.0 7,260 1.97 9,780 41.9 Av. 110 18 Ex. 1 C. SC Semi- 3.0 3,558 1.60 6,120 44.4 Av. 120 12 Ex. 2 active** C. IPM Inert*** 1.0 1,142 1.35 3,840 41.5 Av. 250 4 Ex. 1 Total 8.0 11,960 1.75 19,740 42.8 Av. 130 *OD1 of 32.9 mm, OD2 of 26.9 mm, ID of 5.2 mm, length of 17.5 mm, weight 24.5 g. **OD1 of 32.4 mm, OD2 of 23.3 mm, ID of 11.4 mm, length of 28.6 mm, weight 40.2 g. ***OD1 of 31.4 mm, ID of 16.1 mm, length of 31.3 mm, weight of 57.4 g.

(37) The results of Tables 1 and 2 are compared in Table 3.

(38) TABLE-US-00004 TABLE 3 Comparison of results Pressure drop Side Packing Number GSA (Pa, 453 Voidage crush height (m) of pellets (cm.sup.2/cm.sup.3) m.sup.3/hr flow) (%) (kgf) Comparative 8.0 11,960 1.75 19,740 42.8 Av. 130 example 1 Example 1 8.0 15,172 1.94 18,240 41.1 100 > 220 Difference 3,212 +10.9 ?7.6 ?3.5% At least +70%

(39) As shown by Table 3, the packed catalyst bed containing supported catalysts and inert packing member according to the present invention provide a combination of significantly superior geometric surface area with a lower pressure drop, increased porosity, and significantly higher mechanical integrity.

Support Example 1

(40) Support example 1 was produced from the same composition and method as supported catalyst example 1 with the exception that support example 1 was not impregnated with catalytic material. Support example 1 had a macrostructure and surface structure according to support 402 as shown in FIG. 2a.

Support Example 2

(41) Support example 2 was produced from the same composition and method as supported catalyst example 1 with the exception that support example 2 was not impregnated with catalytic material. Support example 2 had a macrostructure and surface structure according to support 502 as shown in FIG. 3.

Comparative Support Example 1

(42) Comparative support example 1 was produced from the same composition and method as supported catalyst example 1 with the exception that comparative support example 1 was not impregnated with catalytic material. Comparative support example 1 had the same spherical macrostructure as support examples 1 and 2 but had a smooth outer face and therefore no surface structures.

(43) Table 4 provides a comparison of support examples 1 and 2 with comparative support example 1.

(44) TABLE-US-00005 TABLE 4 Comparison of supported catalysts Number of GSA per Change Side packed piece GSA in Porosity crush Example pellets* (cm.sup.2) (cm.sup.2/cm.sup.3) GSA (%) (kgf) Comp. 1455 55.5 1.65 30 >300 kg Example 1 Example 1 1455 64.6 1.91 +16% 30 >300 kg Example 2 1455 103.3 3.06 +86% 30 >300 kg *in a 1 m section of a 250 mm diameter tube

(45) As shown by the data above, supports and supported catalysts according to the present invention show a significant increase in geometric surface area when compared to untextured supports. Furthermore, the increased geometric surface area is achieved in combination with reduced pressure drop, improved side crush strength and higher porosity.

(46) Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

(47) All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

(48) Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

(49) The Invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.