WALL ASSEMBLY FOR CATALYTIC BEDS OF SYNTHESIS REACTORS

Abstract

Gas-permeable assembly (10) for retaining a fine granular catalyst (1) comprising: a first wall (2) arranged to face the catalyst, a second wall spaced from the first wall (4) and arranged to be opposed to the catalyst, a catalyst-retaining core (3) interposed between said first wall and second wall.

Claims

1-18. (canceled)

19. A gas-permeable wall assembly for use in a catalytic reactor for retaining a granular catalyst, the gas-permeable assembly comprising: a first wall arranged to face the granular catalyst; a second wall spaced from the first wall and arranged to be opposed to the granular catalyst; and a catalyst-retaining core interposed between said first wall and said second wall; wherein said catalyst-retaining core has gas passages smaller than gas passage openings of said first wall and said second wall; wherein the catalyst-retaining core includes at least one of the following: a porous medium; a fibrous medium; a micro-fibrous medium; a fabric; or a metallic fiber felt.

20. The gas-permeable assembly according to claim 19, wherein the catalyst-retaining core partially or completely fills the gap between the first wall and the second wall.

21. The gas-permeable assembly according to claim 19, wherein the catalyst-retaining core includes a porous medium and said porous medium is a metal sintered plate.

22. The gas-permeable assembly according to claim 19, wherein the catalyst-retaining core includes a fibrous medium and said fibrous medium is non-woven.

23. The gas-permeable assembly according to claim 19, wherein the catalyst-retaining core includes a fabric and said fabric includes a ceramic or a sintered metal.

24. The gas-permeable assembly according to claim 19, wherein said catalyst-retaining core includes a mesh element sandwiched between reinforcing perforated plates.

25. The gas-permeable assembly according to claim 19, wherein the catalyst-retaining core is able to retain a fine catalyst not contained by the first wall and the second wall, said fine catalyst having a nominal size of catalyst granules not greater than 1.5 mm.

26. The gas-permeable assembly according to claim 19, wherein the catalyst-retaining core is arranged so that part of a pressure exerted by the granular catalyst on the first wall is transferred by the catalyst-retaining core to the second wall, wherein said catalyst-retaining core has a stiffness suitable to transfer part of said pressure exerted by the granular catalyst from the first wall to the second wall.

27. The gas-permeable assembly according to claim 19, wherein the first wall is structurally connected to the second wall.

28. The gas-permeable assembly according to claim 27, wherein the first wall is connected to the second wall through elements regularly spaced.

29. The gas-permeable assembly according to claim 19, wherein the first wall has openings arranged according to a first pattern and the second wall has openings arranged according to a second pattern different from said first pattern.

30. The gas-permeable assembly according to claim 29, wherein the openings of the first wall and the openings of the second wall have an elongated shape or a shape of circular holes.

31. The gas-permeable assembly according to claim 19, wherein the first wall, the second wall, and the catalyst-retaining core are cylindrical.

32. A reactor for the synthesis of chemical compounds, the reactor comprising: at least one catalytic bed of cylindrical annular shape delimited by at least one collector including the gas-permeable assembly according to claim 19.

33. A reactor for the synthesis of chemical compounds, the reactor, comprising: at least one catalytic bed of cylindrical annular shape containing a granular catalyst, wherein said catalytic bed includes at least one collector having a gas-permeable assembly, wherein said gas-permeable assembly includes a first wall facing the granular catalyst, a second wall spaced from the first wall, and a core element between the first wall and the second wall; wherein the first wall and the second wall have gas-passage openings larger than a granule size of the granular catalyst, whilst the core element has gas passages smaller than said granule size of the catalyst, so that the granular catalyst is retained in place by the core element.

34. The reactor according to claim 33, wherein the first wall and the second wall perform a structural load-bearing function.

35. The reactor according to claim 33, wherein the core element includes at least one of: a porous medium; a net; an overlapping of nets; a fibrous medium; a micro-fibrous medium; a fabric; a metallic fiber felt; or a perforated plate.

Description

DESCRIPTION OF THE FIGURES

[0052] FIG. 1 is a schematic drawing of a gas permeable assembly according to a preferred embodiment.

[0053] FIG. 2 is a perspective view of a gas permeable assembly according to an embodiment.

[0054] FIG. 3 is a perspective view of another embodiment of the assembly.

[0055] FIG. 4 is a perspective view of another embodiment of the assembly.

[0056] FIG. 5 is a section of another embodiment of the assembly.

[0057] FIG. 6 is a schematic section of a catalytic bed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0058] FIG. 1 illustrates schematically a cross section of a wall assembly 10 in contact with a catalyst layer 1. For example FIG. 1 illustrates an outer wall assembly of a radial-outward flow catalytic bed.

[0059] The assembly 10 comprises a gas-permeable inner wall 2 facing the catalyst layer 1 and a gas-permeable outer wall 4 opposed to the catalyst. The assembly 10 further comprises a catalyst-retaining core 3 interposed between said inner wall 2 and outer wall 4.

[0060] The catalyst-retaining core 3, enclosed between the two walls 2 and 4, retains the particles of catalyst and may be designed to properly retain a fine catalyst. Conversely, the gas permeable walls 2 and 4 act as structural support to the core 3.

[0061] Openings 5 are located over the surface of said walls 2 and 4 and allow the passages of the gaseous flow through the catalytic bed. The design of said openings 5 may be selected to allow an optimum pressure drop and an optimal gaseous flow distribution across the catalytic bed.

[0062] The openings 5 can be elongated slits as in FIG. 2 or holes as in FIG. 3. The holes can be manufactured through a process cheaper than the conventional methods i.e. a punching method can be used instead of electro-erosion or water-jet cut.

[0063] FIG. 2 illustrates an embodiment wherein the inner wall 2 and outer wall 4 have opening 5 with a different pattern. Particularly FIG. 2 illustrates an embodiment wherein the openings are in the form of elongated slits arranged in a first direction on the inner wall 2 and in a second direction on the outer wall 4.

[0064] The walls 2 and 4 may be interconnected through welding elements not shown in the figures. The number and dimension of the said continuous elements are defined by structural integrity requirements.

[0065] FIG. 4 illustrates an example of a core 3 made of a demister pad-type mesh.

[0066] FIG. 5 illustrates an example wherein the core 3 has a reinforced mesh structure including a mesh element 30 sandwiched between perforated reinforcing plates 31, 32.

[0067] FIG. 6 is a sketch of an annular-cylindrical catalytic bed 20 showing the position of the inner collector and outer collector made with the assembly 10.

[0068] The bed 20 has an axis A-A and a central cavity 21. In some embodiments, an inter-bed heat exchanger may be mounted in the cavity 21.