CATALYTIC REACTOR COMPRISING FIBROUS CATALYST PARTICLES SUPPORT

Abstract

The present disclosure relates to a reactor containing of catalyst particles, a layer of fibrous catalyst particles support below said catalyst particles and a lower means of structural support below said catalyst particles with the associated benefit of such a reactor having increased space for catalyst particles, compared to a reactor with inert particles supporting the catalyst particles.

Claims

1. A reactor containing catalyst particles, a layer of fibrous catalyst particles support below said catalyst particles and a lower means of structural support below said catalyst particles, wherein the ratio between width and thickness of the fibrous catalyst particles support is at least 50:1 and the fibrous catalyst particles support allows passage of a liquid.

2. A reactor according to claim 1 in which said layer of fibrous catalyst particles support comprises oxide fibres.

3. A reactor according to claim 1 in which said layer of fibrous catalyst particles support comprises non-oxide material.

4. A reactor according to claim 1 in which said layer of fibrous catalyst particles support comprises oxide fibers as well as non-oxide material.

5. A reactor according to claim 4 in which said layer of fibrous catalyst particles support is a composite on fibre level.

6. A reactor according to claim 4 in which said layer of fibrous catalyst particles support is a layered composite comprising a layer of a material comprising oxide fibres and a second layer comprising non-oxidic fibres.

7. A reactor according to claim 1 in which said layer of fibrous catalyst particles support provides retention for particles with a diameter above 0.1 mm.

8. A reactor according to claim 1 in which said layer of fibrous catalyst particles support provides a resistance to a flow of a mixture below 1.5 kPa when said mixture comprises a gas with a viscosity of 0.017 cP and flowing through the fibrous catalyst particles support with a linear flow rate of 250 m/h; and a liquid with a viscosity of 0.15 cP, flowing through the fibrous catalyst particles support with a linear flow rate of 25 m/h.

9. A reactor according to claim 1 further comprising an upper means of structural support between said catalyst particles and said fibrous catalyst particles support.

10. A reactor according to claim 9 further comprising a means for separating said upper means of support from said lower means of support by a difference of 2 mm.

11. A reactor according to claim 1 further comprising a layer of inert particles between below said catalyst particles and above said fibrous catalyst particles support.

12. A reactor according to claim 1 further comprising a non-fibrous screen, such as a single strand woven structure or a plate having cut slits positioned below said fibrous catalyst particles support.

13. A method comprising using fibrous materials as a fibrous catalyst particles support retaining catalyst particles in a reactor bed of a trickle flow reactor, wherein the fibrous catalyst particles support is positioned below the bed of catalyst particles and above a structural support.

14. A reactor according to claim 2 in which said oxide fibres are alumina, silica, or borosilicates.

15. A reactor according to claim 3 in which said non-oxide material is carbon fibre or metal wool.

16. A reactor according to claim 7 in which said layer of fibrous catalyst particles support provides retention for particles with a diameter above 0.5.

17. A reactor according to claim 7 in which said layer of fibrous catalyst particles support provides retention for particles with a diameter above 1 mm.

18. A reactor according to claim 8, wherein said layer of fibrous catalyst particles support provides a resistance to a flow of a mixture below 0.7 kPa.

19. A reactor according to claim 8, wherein said layer of fibrous catalyst particles support provides a resistance to a flow of a mixture below 0.3 kPa.

20. A reactor according to claim 9 further comprising a means for separating said upper means of support from said lower means of support by a difference of 6 mm.

21. A reactor according to claim 9 further comprising a means for separating said upper means of support from said lower means of support by a difference of 20 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The disclosure is further illustrated by the accompanying drawings showing examples of the prior art or examples of embodiments of the invention.

[0048] FIG. 1 shows an example of a loading diagram in a multi-layer three-bed reactor for hydroprocessing in the current art.

[0049] FIG. 2 shows an example of a loading diagram in a multi-layer three-bed reactor for hydroprocessing according to an embodiment of the invention.

POSITION NUMBERS

[0050] 01. Cylindrical reactor. [0051] 02. Large inert particles. [0052] 03. Medium inert particles. [0053] 04. Small inert particles. [0054] 05. Type 1 catalyst particles. [0055] 06. Type 2 catalyst particles. [0056] 07. Type 3 catalyst particles. [0057] 08. Type 4 catalyst particles. [0058] 09. Type 5 catalyst particles. [0059] 10. Type 6 catalyst particles. [0060] 11. Type 7 catalyst particles. [0061] 12. Type 8 catalyst particles. [0062] 13 Feed [0063] 14 Treat gas [0064] 15 Void [0065] 16 Quench [0066] 17 Effluent [0067] 20. Catalyst particles support. [0068] 21. Outlet collector. [0069] 22. Outlet pipe. [0070] 23. Distribution tray. [0071] 24,25,26 Fibrous catalyst particles support. [0072] 33 Large inert particles. [0073] 34 Small inert particles. [0074] 43 Large inert particles. [0075] 44 Small inert particles.

DESCRIPTION OF THE DRAWINGS

[0076] A catalytic bed reactor may comprise one or more catalytic beds. FIG. 1 shows an example of a catalytic bed from the art. The reactor of this example (01) receives a flow of feed (13) and treat gas (14), as well as two quench (16) streams for cooling and providing extra hydrogen. Effluent (17) is withdrawn at the reactor outlet (22). The reactor is a hydroprocessing reactor with 3 beds: a top (10,11), a middle (08,09) and a lower bed (05,06,07), all the three beds comprising multiple layers of catalyst particles (05-11). Above the beds are a distribution tray (23) and a void (15), allowing for mixing. The catalyst particles in the layers are not necessarily all different and do not necessarily all have catalytic propertiessome of the catalyst particles may be selected because of physical properties and functionalities. The reactor furthermore comprises an outlet collector (21), at the exit of a reactor, typically at the bottom, as in FIG. 1. An outlet collector has the function to prevent catalyst particles from leaving the reactor and being transported to the downstream equipment through the outlet pipe (22). For this purpose, the outlet collector comprises a metallic screen (not shown). The outlet collector and the screen are subject to strength and durability requirements. The screen mesh is required to hold small catalyst particles and avoid unnecessary pressure differential across the outlet collector. A catalyst loading comprises inert particles to separate the outlet collector from the catalyst particles bed (02-04).

[0077] Each bed of the reactor further comprises a catalyst particles support (20). A catalyst particles support comprises a structural support with screens (not shown), designed with similar consideration as an outlet collector screen. A bed loading of a small-sized catalyst particles above a catalyst particles support as known from the art comprises at least one layer of inert particles between the catalyst particles and the screen of the catalyst particles support. In FIG. 1, there are two layers of inert particles, of type 34 and 44 (small and in contact with the catalyst particles), and of type 33 and 43, of intermediate size, in contact with the catalyst particles support screen

[0078] FIG. 2 shows an embodiment of the reactor according to the disclosure. Nomenclature is the same as in FIG. 1. The reactor (01) receives a flow of feed (13) and treat gas (14), as well as two quench (16) streams for cooling and providing extra hydrogen. Effluent (17) is withdrawn at the reactor outlet pipe (22). Also this reactor has distribution trays (23) and a voids (15), allowing for mixing. Fibrous catalyst particles support (24, 25, and 26) positioned on the catalyst support grid (20) replaces almost all of the inert particles (indicated with 03, 04, 33, 34, 43, 44 in FIG. 1) at the bottom of the three catalyst particles beds, leaving only a single layer (02). In other embodiments the fibrous catalyst particles support (24) may be laid on the screen of the outlet collector (21) replacing also the layer of inert particles (02). In this embodiment, a fibrous catalyst particles support (25, 26) is placed on top of the catalyst particles support holding the top bed (10,11) and the middle bed (08,09) and the catalyst particles bed is loaded directly on the fibrous catalyst particles support. In the embodiment, an additional volume of the same type of catalyst particles (10) may fill the space filled by the inert particles in FIG. 1 and not occupied by the catalyst particles screen for the top bed. With regards to the middle layer, a new catalyst type (12) fills the space left free by the inert particles and not occupied by the catalyst particles screen. With regards to the lower bed, the fibrous catalyst particles support (24) is placed above inert particles of the largest type (02) and allows to increase the height of catalyst particle layer (05).

[0079] The catalyst loading volume provided by replacing inert particles by fibrous catalyst particles support allows flexibility to the selection and design of the catalyst loading. This may result in a flexibility for increasing or decreasing the height of the layer of catalyst particle type 4 (08) in the middle bed of FIG. 2, relative to the same layer in FIG. 1, as appropriate for the optimization of the operations.

[0080] The fibrous catalyst particles supports (24, 25, 25) may be of the same type, but they may also be of different types depending upon the material that they have to retain and other characteristics required by the process.

Example

[0081] The height of each layer for a hydroprocessing reactor as from the art is given in Table 1 (second column). If part of the inert particles is replaced by the fibrous catalyst particles support, as shown in the embodiment of FIG. 2 with respect to the current art loading of FIG. 1, the height available for the catalyst changes as in Table 1, third column. In this embodiment, the disclosure allows an increase of catalyst volume type 6 (layer 10) by 5.8%. Furthermore, the disclosure allows introducing a layer of 75+75-6 mm of catalyst particle type 8 (layer 12) below catalyst particle type 4 (08), being this layer 6.1% of the original layer of catalyst particle type 4 (08); and a further increase of catalyst volume of catalyst particle type 1 (05) by 18.7% at the bottom bed.

[0082] In addition, as the fibrous catalyst particles support is placed on top of the two catalyst particles supports, by means of the disclosure the maintenance operations concerned with cleaning the screens of the two catalyst particles supports become unnecessary, with consequent decrease of the reactor maintenance time.

TABLE-US-00001 TABLE 1 FIG. 1 FIG. 2 Layer position Height (mm) Height (mm) 11 150 150 10 2480 2624 44 75 43 75 26 6 9 150 150 8 2340 2340 12 144 34 75 33 75 25 6 7 150 150 6 3330 3330 5 1090 1294 4 75 3 75 24 6 2 160 100