WO2010002362A1

WO2010002362A1 - Porous flame barrier and fluid management structures in extruded monolith falling film reactors

Info

Publication number: WO2010002362A1
Application number: PCT/US2008/008190
Authority: WO
Inventors: James S Sutherland
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2008-07-01
Filing date: 2008-07-01
Publication date: 2010-01-07
Anticipated expiration: 2011-01-01

Abstract

A reactor includes a multicellular extruded body oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end. A first plurality of the cells is open at both ends of the body. A second plurality of the cells is closed at both ends of the body and arranged in one or more groups of contiguous cells and cooperating to define one or more fluidic passages extending through the body laterally. The reactor further includes either (1) a liquid receiving structure positioned at or below the lower end of the body and a porous flame barrier covering the open cells at the lower end of the body, the flame barrier having 1) a non-planar lower surface, 2) a varying pore structure, 3) a wettability gradient or 4) a combination of any of 1)-3), arranged so as to guide a liquid communicated from the open cells at the lower end of the body toward the liquid receiving structure; (2) a liquid reservoir at the upper end of the body and a porous flame barrier covering the open cells at the upper end of the body and positioned to contact a liquid in the reservoir and to guide the liquid to the open cells at the upper end of the body or (3) the first plurality of cells having each cell provided with a porous flame barrier plug at one or both ends of the body.

Description

POROUS FLAME BARRIER AND FLUID MANAGEMENT

STRUCTURES IN EXTRUDED MONOLITH

FALLING FILM REACTORS

[0001] The present application is related to application number EP08305041 filed 29 February 2008 entitled "Methods and Devices for Falling Film Reactors with Integrated Heat Exchange" and assigned to assignee of the present invention and to U.S. Provisional Application Serial No. 60/921,053, filed 31 March 2007 entitled Honeycomb Continuous Flow Reactor and to U.S. Provisional application 61/018,119 filed 31 December 2007 entitled Devices and Methods for Honeycomb Continuous Flow Reactors.

BACKGROUND

[0002] The present invention relates to a methods and devices for falling film reactors and falling film reactions, and more particularly to devices and methods for flame suppression and fluid distribution in falling film reactors with integrated heat exchange.

SUMMARY

[0003] According to one aspect of the invention, a reactor for reacting a gaseous reactant stream with a falling film liquid reactant stream includes a multicellular extruded body oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end. A first plurality of the cells is open at both ends of the body. A second plurality of the cells is closed at both ends of the body and arranged in one or more groups of contiguous cells and cooperating to define one or more fluidic passages extending through the body laterally. The reactor further includes either (1) a liquid receiving structure positioned at or below the lower end of the body and a porous flame barrier covering the open cells at the lower end of the body, the flame barrier having 1) a non-planar lower surface, 2) a varying pore structure, 3) a wettability gradient or 4) a combination of any of l)-3), arranged so as to guide a liquid communicated from the open cells at the lower end of the body toward the liquid receiving structure; or (2) a liquid reservoir at the upper end of the body and a porous flame barrier covering the open cells at the upper end of the body and positioned to contact a liquid in the reservoir and to guide the liquid to the open cells at the upper end of the body. The flame barrier covering the open cells at the upper end of the body may similarly include one of 1) a non-planar upper surface 2) a varying pore structure 3) a wettability gradient or 4) a combination of any of l)-3), arranged so as to guide a liquid in the reservoir to the open cells at the upper end of the body.

[0004] According to another aspect of the invention, a reactor for reacting a gaseous reactant stream with a falling film liquid reactant stream includes a multicellular extruded body oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end. The body has a first plurality of cells, each cell of which is provided with a porous flame barrier plug at one or both ends of the body, the first plurality of cells being open to fluid through said porous plugs. The body also has a second plurality of cells each of cell of which is closed at both ends of the body. The cells of the second plurality are arranged in one or more groups of contiguous cells and cooperate to define one or more fluidic passages extending through the body laterally from cell to cell within cells of the second plurality. The reactor further includes either or both of (1) a liquid reservoir positioned at the upper end of the body so as to be able to deliver liquid to porous plugs at the upper end of the body, and (2) a liquid receiving structure positioned at or below the lower end of the body so as to be able to receive liquid from porous plugs at the lower end of the body.

[0005] Additional variations and features of the present invention are described below in connection with the figures, of which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a plan view of reactor component comprising an extruded multicellular body or honeycomb showing a fluidic path in a plane perpendicular to the cells according to one embodiment of the present invention.

[0007] Figure 2 is a side elevation view of the reactor component comprising an extruded multicellular body or honeycomb of Figure 1, showing additional detail of a fluidic path according to an embodiment of the present invention.

[0008] Figure 3 is a cross-sectional view of cells closed on one or both ends of an extruded body, showing one method useful in the context of the present invention for interconnection between cells.

[0009] Figure 4 is a cross-sectional view of cells closed on one or both ends of an extruded body, showing another method useful in the context of the present invention for interconnection between cells.

[0010] Figures 5A-5D are alternative plan views of an end of an extruded body 20 showing alternative patterns for the plugs 26 or continuous plug material 26, corresponding to the pattern of the closed cells beneath.

[0011] Figure 6 a cross section of an extruded body 20 showing liquid and gas reactant and heat exchange fluid distribution.

[0012] Figure 7 is a perspective view showing multiple bodies 20A-20D arranged as part of a single reactor 10.

[0013] Figure 8 is cross-section showing one embodiment having flame barriers in the form of flame barrier screens 84.

[0014] Figure 9 is a cross-section showing porous flame barriers 96, 98 structured and arranged to assist in reactant liquid distribution.

[0015] Figure 10 is a cross section showing another embodiment of a porous body flame barrier 96 structured and arranged to assist in reactant liquid distribution.

[0016] Figure 11 is a cross section showing yet another embodiment of porous flame barriers 96, 98.

[0017] Figure 12 is a cross section showing still another embodiment of a porous flame barrier 98 according to another embodiment of the present invention. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to the presently preferred embodiments of the invention, instances of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. Features described as desirable are preferred but optional, representative of variations of the invention.

[0019] The present invention relates to methods and devices for falling film reactions, particularly to methods for preventing flame propagation and controlling liquid flow. In Figure 1 is shown a plan view, and in Figure 2 a perspective view, of a reactor component 12 useful in the devices and methods of the present invention. The reactor component 12 comprises a multicellular extruded body 20, one embodiment of which is represented in Figures 1 and 2. The body 20 has a plurality of cells extending in parallel in a direction from one end of the body to the other, with the cells seen end-on in Figure 1. The cells include a first plurality of cells 22 open at both ends of the body and a second plurality of cells 24 closed at both ends of the body, in this embodiment by one or more plugs 26 or by a more or less continuous plugging material 26 disposed at or near the end of the body and at least partly within the channels of the second plurality of cells 24. The second plurality of cells 24 (the closed cells) are positioned in one or more groups of contiguous cells, one group in the case of Figure 1, and cooperate to help define a fluidic passage 28 extending through the body 20 from an input port 30 to an output port 31 at the locations indicated, but not visible in the figure. The passage 28 desirably follows a serpentine path up and down along the cells 24, in the general direction shown in Figure 2. The passage or path 28 desirably extends laterally perpendicular to the cells 24 only at or near the ends 32, 34 of the body 20, where walls between the cells 24 are shortened or ported or otherwise passed over or through so as to allow fluid communication between the cells 24.

[0020] Embodiments of a body 20 having shortened walls between the cells 24 are shown in the cross sections of Figures 3 and 4, one method of allowing the passage or path 28 to extend laterally perpendicular to the cells 24 by connecting at or near the ends of the body 20. As may be seen in Figure 3, the path 28 may follow a single cell up and down in the direction along the cells 24. Alternatively, the path 28 may follow multiple successive respective groups 25 of two or more cells in parallel, in the direction along the cells, as shown in Figure 4. In the embodiment shown, the path follows groups 25 of two cells in parallel, but more than two cells may be included in each group 25 if desired. [0021] Four alternative paths for the passage or path 28, from among many potential alternatives, are shown in plan view in Figures 5A-5D. In Figure 5 A, the plurality of cells closed by plugs 26 or continuous plugging material 26 lies in a single straight line in the plane perpendicular to the cells of the body 20. In the embodiment shown in Figure 5B, the path is not serpentine only in the direction along the cells as shown in Figure 2, but also in the plane perpendicular to the cells. The fluid path 28 of Figure 5B is thus serpentine at a relatively higher frequency in the direction in and out of the plane of Figure 5B, and at a relatively lower frequency within the plane of the figure. As shown in Figures 5 C and 5D, the path 28 may also be made parallel, internally as in Figure 5 C or externally as in Figure 5D, with separate sets of continuous plugging material 26 A-E or groups of plugs 26 A-E. In every case, the path or passage 28, or the multiple paths or passages 28, all extend through the body 20 laterally from cell to cell within cells of the second plurality of cells 24, that is, the closed cells 24 corresponding to those indicated in Figure 1.

[0022] Regardless of the shape of the path 28 within the plane perpendicular to the direction of the cells, it is desirable that the majority of the path or passage 28 be only one cell wide in said plane. This results in an easily manufactured fluidic path capable of having a very high shared surface area with the cells of the first plurality 22, that is, the open cells 22. It is likewise preferable that the open cells 22 positioned between rows of the path or passage 28 be arranged in groups only one cell wide, as in Figures 5B-5D. This provides for a fluid path through the open cells that has a high surface to volume ratio. Paths 28 may however, if desired, be more than one cell wide, as may the groups of open cells. [0023] The extruded body or honeycomb 20 is desirably formed of an extruded glass, glass-ceramic, or ceramic material for durability and chemical inertness. Alumina ceramic is generally presently preferred as having good strength, good inertness, and higher thermal conductivity than glass and some ceramics. Other higher thermal conductivity materials may also be employed. The multicellular body may have cell density as high as 200 cells per square inch. Even higher densities can lead to higher heat exchange performance devices. Bodies having 300 or more, or even 450 or more cells per square inch may be of potential interest for forming high performance devices. High flow devices may be formed using cell densities even lower than 200 cells per square inch, if desired.

[0024] An embodiment of the use of a device according to Figures 1-5 for a falling film reaction is shown in the diagrammatic cross section of Figure 6. A liquid reactant stream 62 is delivered to the surface of the plugs 26 or continuous plugging material 26, or in other words, to the surface above the closed cells of the body 20. As shown in the cross section of Figure 6, the liquid reactant stream 62 then follows the path shown by the arrows 62 representing the liquid reactant stream 62, flowing over the edges of the closed cells of the body 20, and down the inside surfaces of the open cells as a falling liquid film. Gaseous reactant stream 48 flows in the center of the open cells, in co- or in counter-current flow as may be desired, while a heat exchange fluid is flowed along passage 28. The heat exchange fluid may optionally be in the form of a phase-transforming fluid or in the form of a reactant stream providing a reaction that acts as a source or sink of heat,

[0025] As shown in the perspective view of Figure 7, a reactor 10 may comprise a stack of multiple components 12 each formed from a respective extruded body 20A-20D. Each component 12 may be provided with an individual heat-exchange fluid input port 3OA-3OD and heat-exchange fluid output port 31A-31D, allowing for high total heat-exchange fluid flow rates, and optionally allowing for different temperature fluids and different flow rates for different temperatures of bodies 20A-20D or different heat exchange rates, as appropriate. As another option, open cells 22 of the various bodies 20A-20D may include, in or on their interior surfaces, one or more catalytic materials, depending on the desired reactions to be performed. One or more catalysts may likewise be used, as desired, in any of the other embodiments shown or described herein. The respective vertical lengths of each body 20A-20D may also be chosen for the needs of the reaction to be performed: they need not be of uniform length, as illustrated by the shorter body 2OC.

[0026] It is desirable in the context of some falling film reactions to prevent potential flame or explosion propagation within the reactor 10, as flammable or explosive reactants may be used, or flammable or explosive products may be produced. Accordingly, as one alternative within the context of the present invention, a flame barrier screen 84 may be positioned between neighboring pairs of bodies 20A-20C, as shown in Figure 8. For purposes of reactor design and reaction engineering, along with the use of screens 84, the length of the bodies 20A-20C (that is, the length of the open cells) and the width of the open cells can be chosen to avoid any risk of out-of-control or explosive reactions. Again, lengths of extruded bodies may be different as needed for this optimization.

[0027] According to one embodiment of the present invention, at the top or bottom of a reactor 10 or both, porous flame barriers are used, such as the porous flame barriers 96 and 98 of Figure 9. The porous flame barrier 96 covers the open cells 22 at the upper end 34 of the body 20. As with a woven flame barrier or screen, fine openings in the (open) porous material allow gas reactants to pass through the barrier while preventing flame propagation. The porous material may be formed from a corrosion-resistant metal aerogel or porous ceramic material or the like, depending on chemical corrosion resistance requirements. [0028] The reactor 10 of Figure 9 includes a liquid reservoir 64 structured to be able to hold a liquid at the upper end of the body, in the form of an annular ring 67. The liquid reservoir 64 and the porous flame barrier 96 at the top of the body 20 are positioned relative to each other such that the porous flame barrier is able contact a liquid 61 in the reservoir 64 and to guide the liquid to the open cells 22 at the upper end of the body 20, to flow down the walls thereof, as shown by the liquid flow 62 or liquid flow path 62. The reactive gas flow 48 is desirably in the co-current direction, as it can then more directly assist in moving the liquid flow 62 from the porous flame barrier 96 into a falling film state.

[0029] Unlike a woven flame barrier, a porous flame barrier material is readily formed into more complex shapes via molding, machining and/or lamination. For example, the porous flame barrier 98 covering the open cells 22 at the lower end of the body 20 may have a non-planar lower surface tending to guide a liquid communicated from the open cells 22 at the lower end 32 of the body 20 toward a liquid receiving structure 66 positioned at or below the lower end of the body 20. As alternatives or in addition to a non-planar lower surface 99, the porous flame barrier 98 may be provided with a varying pore structure, a surface wettability gradient or combinations of these properties arranged to guide a liquid 62 or liquid flow 62 communicated from the open cells 22 at the lower end 32 of the body 20 toward the liquid receiving structure 66, where it gathers as collected liquid 63. For example, the pore size of the porous material of barrier 98 can be graded from large in the center of the lower end of the body 20 to small towards the perimeter of the lower end, to promote liquid reactant flow toward the perimeter of the end face.

[0030] In the embodiment of Figure 9, the liquid receiving structure 66 is in the form of an annular trough 67, and the non-planar surface 99 includes a central gently downward-sloping surface and a raised rim 101 positioned over the trough 67 to assist in guiding the liquid flow 62. The slightly angled downward sloping surface promotes liquid flow away from the center of the flame barrier 98, while the sharply angled rim 101 assists in droplet formation and removal. Co-current direction of the gas flow is desirable here also, as it assists in moving the liquid flow 62 in the flame barrier 98 away from the areas blow the open cells 22. [0031] It may be undesirable to have drops of liquid reaction product in direct contact with gas reactants within the falling film reactor, since an explosion hazard may result from the large gas-liquid interface area of the drop combined with the relatively large volume of liquid reaction product in the drop. To avoid unwanted combustion as the liquid reaction product exits the porous flame barrier 98, the entire receiving structure 66 can be flooded with a non-reactive gas such as nitrogen.

[0032] This may be achieved by use of a gas curtain containment structure 100, as shown in Figure 9. In the embodiment of Figure 9, a shroud 102 cooperates with the annular trough 67 to form a gas containment structure 100, including openings 103 through which a non-reactive gas may be fed in the direction of the arrows 104. By keeping a slight positive pressure in the structure 100 by means of feeding a non-reactive gas, the non-reactive gas can isolate liquid in the liquid collection structure 66 or trough 67 from the reactant gas flow 48 flowing in the open cells of the body 20.

[0033] Providing a non-reactive atmosphere at positive pressure in the receiving structure 66 prevents gas reactants from entering. Instead a small amount of the non-reactive gas exits the receiving structure 66 and joins the gas reactant flow 48 as it flows downward to exit the reactor 10. If desired, an auxiliary flame barrier 86 in the form of a flame barrier screen or the like may be positioned below the lower end of the body 20 as shown in Figure 9 to further isolate the fluid flowing into and contained in the fluid receiving structure 66. [0034] Similarly to the porous flame barrier 98 at the lower end of the body 20, the porous flame barrier 96 at the upper end of the body may likewise include one of 1) a non-planar upper surface 2) a varying pore structure 3) a wettability gradient or 4) a combination of any of l)-3) in order to help to guide a liquid in the reservoir the open cells at the upper end of the body, to flow down the walls thereof. One embodiment of such an upper porous flame barrier 96 is shown in the cross section of Figure 10.

[0035] In the embodiment of Figure 10, an upper porous flame barrier 96 includes an upper porous distribution layer 92 joined to a lower porous flame barrier material 94. The upper porous distribution layer 92 is structured in a pattern of multiple distribution "fingers" or channels 90, which may optionally include one or more crossing "fingers" or channels such as crossing channel 88. The material and/or porosity of the upper layer 92 is selected to direct liquid reactants more uniformly to open cells of the body 20, while the lower layer material and/or porosity enables passage of gas reactants while preventing flame propagation. The pore sizes for the two material layers can be optimized independently to improve both the fluid transport and flame barrier functions. For example, the pore size of the upper layer porous distribution channels or fingers can be larger than the lower layer flame barrier, to promote liquid reactant wicking from the upper distribution layer to the lower flame barrier. [0036] Another embodiment of the present invention is shown in the cross-section of Figure 11. In the embodiment of Figure 11, a reactor 10 for reacting a gaseous reactant stream 48 with a falling film liquid reactant stream 62 includes a multicellular extruded body 2OA or 2OB oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end. In this embodiment, a first plurality of the cells, cells 22, is each provided with a porous flame barrier plug 27 at one or both ends of the body. The porous plugs 27 at one or both ends of the body 20 may in the form either of individual porous plugs 27 or of a continuous porous plugging material 27, as may be desired. The first plurality of cells 22 is open to fluid flow through the porous plugs 27. A second plurality of cells, cells 24, is closed at both ends of the body 2OA or 2OB, desirably by non-porous plugs 26 or continuous plugging material 26. The second plurality of cells 24 is arranged in one or more groups of contiguous cells and cooperates to define one or more fluidic paths or passages 28 extending through the body 20 laterally from cell to cell within cells of the second plurality, as shown and described above with respect to Figures 1-5. [0037] The embodiment of Figure 11 further includes either or both of (1) a liquid reservoir 64 positioned at the upper end of the body 20 so as to be able to deliver liquid to porous plugs 27 at the upper end of the body, and (2) a liquid receiving structure 66 positioned at or below the lower end of the body 20 so as to be able to receive liquid from porous plugs 27 at the lower end of the body.

[0038] For ceramic and related plugging materials, porous plugs 27 may be formed by the use of pore-forming additives in forming a sintered ceramic plug. Pore size can be controlled by adjusting the size of pore formers as well as sintering conditions. Alternatively, metallic mesh or metallic wool may be used to plug the ends of the cells 22, forming porous plugs 27. [0039] In operation of the reactor of Figure 11, when liquid reactant floods the top end of the extruded body 2OA, fluid flows along paths defined by the closed cells 24, that is by the tops of the non-porous plugs 26. Co-directional gas reactant flow 48 then promotes liquid reactant flow 62 through the porous plugs 27 and onto the sidewalls of the open cells 22. [0040] At the lower end 32 of the extruded body 2OB, liquid reaction product is forced through the porous plugs 27 so that it collects on the surface of the end 32. When enough liquid reaction product collects, excess liquid will flow to the perimeter of the end 32 and meet a liquid removal structure 106 that is integral to or fixed on the extruded body 2OB. Liquid reaction product will then flow, wick or drip off the removal structure 106 and collect in the receiving structure 66. As in the embodiment of Figure 9, the can liquid receiving structure 66 may be flooded with a non-reactive gas to prevent unwanted reactions at the gas-liquid interface of the drop, or at the collected liquid reaction product surface. [0041] As shown in the embodiment of Figure 11, the reactors 10 of the present invention may employ additional flame barrier screens 84 positioned away from the bottom end 32 and top end 34 of a stack of extruded bodies 20A-20B, to segment the internal volume of the reactor 10 into small zones that are intrinsically safe. More than two extruded bodies 2OA and 2OB may be employed to further segment the internal volume of the reactor 10 as needed or desired.

[0042] Where multiple extruded bodies 2OA and 2OB are used in succession and where it is not practical that they be cut from a single longer body, a transitional extruded body section 80 may be employed, if desired, to assist in communicating the falling film fluid flow 62 from an upper body 2OA to a lower body 2OB. The transitional extruded body section 80 desirably has different cell pitch or spacing than bodies 2OA and 2OB, allowing a flowing fluid to more or less randomly redistribute itself evenly into the lower body 2OB. Smaller cell pitch may be useful for preventing flame propagation. It may be desirable to use two flame barrier screens, one on each side of the transitional extruded body 80, particularly if a larger cell size is used.

[0043] The cross section of Figure 12 shows yet another alternative embodiment of the present invention, in which a lower porous flame barrier includes multiple protrusions 108 positioned in alignment with closed cells 24, or in alignment with plugs 26, as well as in alignment with a liquid receiving structure 66 in the form of a grid or array of troughs 67. In the device of the embodiment of Figure 12, reactant gas flow 48 drives reactant fluid flow 62 away from the area directly below the open cells and to the area of the protrusions 108 and the troughs 67.

[0044] Across all embodiments and variations of the present invention, it is desirable that the one or more passages 28 extending through the body 20 laterally from cell to cell within the closed cells 24 have a serpentine path back and forth along cells of the second plurality, said path connecting laterally from cell to cell at or near the ends of the body. By utilizing a serpentine path and interconnecting at or near the ends of the body, the internal cell walls of the body 20 are largely preserved, and the native mechanical properties such as strength, pressure resistance, thermal shock resistance and the like of the extruded body 20 are thus well retained.

[0045] Where high flow rates are desired in the path or passages 28 for high heat exchange rates, it is also desirable across all embodiment and variations of the invention that least one of the one or more fluidic passages 28 follows multiple successive respective groups 25 of two or more cells in parallel, in the direction along the cells, as shown and described above with respect to Figure 4.

Claims

What is claimed is:

1. A reactor for reacting a gaseous reactant stream with a falling film liquid reactant stream, the reactor comprising: a multicellular extruded body oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end, the body having a first plurality of said cells open at both ends of the body and a second plurality of said cells closed at both ends of the body, the second plurality of cells being arranged in one or more groups of contiguous cells and cooperating to define one or more fluidic passages extending through the body laterally from cell to cell within cells of the second plurality; a liquid receiving structure positioned at or below the lower end of the body; and a porous flame barrier covering the open cells at the lower end of the body, the flame barrier having 1) a non-planar lower surface, 2) a varying pore structure, 3) a wettability gradient or 4) a combination of any of l)-3), arranged so as to guide a liquid communicated from the open cells at the lower end of the body toward the liquid receiving structure.

2. The reactor according to claim 1 , further comprising a liquid reservoir structured to be able to hold a liquid at the upper end of the body; and a porous flame barrier covering the open cells at the upper end of the body and positioned so as to be able contact a liquid held in the reservoir and to guide the liquid to the open cells at the upper end of the body.

3. A reactor for reacting a gaseous reactant stream with a falling film liquid reactant stream, the reactor comprising: a multicellular extruded body oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end, the body having a first plurality of said cells open at both ends of the body and a second plurality of said cells closed at both ends of the body, the second plurality of cells being arranged in one or more groups of contiguous cells and cooperating to define one or more fluidic passages extending through the body laterally from cell to cell within cells of the second plurality; a liquid reservoir structured to be able to hold a liquid at the upper end of the body; and a porous flame barrier covering the open cells at the upper end of the body and positioned so as to be able contact a liquid in the reservoir and to guide said liquid to the walls of the open cells at the upper end of the body.

4. The reactor according to either of claims 2 and 3, wherein the porous flame barrier at the upper end of the body includes one of 1) a non-planar upper surface 2) a varying pore structure 3) a wettability gradient or 4) a combination of any of l)-3), arranged so as to guide a liquid in the reservoir to the open cells at the upper end of the body.

5. A reactor for reacting a gaseous reactant stream with a falling film liquid reactant stream, the reactor comprising: a multicellular extruded body oriented with the cells thereof extending in parallel in a generally vertical direction from an upper end of the body to a lower end, the body having a first plurality of said cells, each provided with a porous flame barrier plug at one or both ends of the body, said first plurality of cells being open to fluid through said porous plugs, and a second plurality of said cells closed at both ends of the body, the second plurality of cells being arranged in one or more groups of contiguous cells and cooperating to define one or more fluidic passages extending through the body laterally from cell to cell within cells of the second plurality; and either or footh of (1) a liquid reservoir positioned at the upper end of the body so as to be able to deliver liquid to porous plugs at the upper end of the body, and (2) a liquid receiving structure positioned at or below the lower end of the body so as to be able to receive liquid from porous plugs at the lower end of the body.

6. The reactor according to any of claims 1, 2, and 5 wherein the liquid receiving structure is in the form of an annular trough.

7. The reactor according to any of claims 3, 4, and 5 wherein the liquid reservoir is in the form of an annular trough.

8. A reactor according to any of claims 1-7, further comprising one or more gas containment structures partially enclosing either the liquid collection structure or the liquid reservoir or both, such that a purge gas fed into the one or more gas containment structures can isolate liquid in the liquid collection structure or in the liquid reservoir from a reactant gas flowing through the first plurality of cells.

9. A reactor according to any of claims 1-8 wherein the one or more passages extending through the body laterally from cell to cell have a serpentine path back and forth along cells of the second plurality, said path connecting laterally from cell to cell at or near the ends of the body.

10. A reactor according to claim 9 wherein at least one of the one or more fluidic passages follows multiple successive respective groups of two or more cells in parallel, in the direction along the cells.