Multi-zone filtration device for down-flow hydrotreating reactor

Abstract

A multi-zone filtration device for a down-flow catalytic hydrotreating reactor is disclosed. The filtration device may be used in the petroleum and chemical processing industries to catalyze the reaction of hydrocarbonaceous feedstocks at elevated temperature and pressure in the presence of hydrogen to remove contaminants from mixed gas and liquid feed streams to the reactor catalyst bed. The filter device may be provided as a horizontally mounted apparatus at the top of the reactor, whereby the feed stream liquid passes through the filter media zone in a radial flow direction. In one zone, flow flows radially outward from the center of the zone of the filtration device to the wall of the reactor. In another zone, the flow flows radially inward from the wall of the reactor to the center of the zone of the filtration device. The liquid flows to the reactor catalyst bed after passing through the filtration device. The benefits provided include: minimizing fouling and small / fine particles reaching the catalyst bed below the device; the pressure drop in the reactor is reduced, even when the filter is fully scaled; the catalyst volume may be increased because the need for use of catalyst grading materials is reduced; and increases the likelihood of reducing maintenance requirements during reactor operation, such as top bed skimming or filter media replacement, thereby extending the length of reactor run time.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 63 / 418,189, filed Oct. 21, 2022, entitled “MULTI - ZONE FILTRATION DEVICE FOR A DOWN - FLOW HYDROPROCESSING REACTOR”, the disclosure of which is incorporated herein by reference in its entirety. Field of the Invention

[0003] Disclosed is a multi - zone filtration device for a down - flow catalytic hydroprocessing reactor. The filtration device can be used in the petroleum and chemical processing industries to catalytically react hydrocarbon - containing feeds in the presence of hydrogen at high temperature and pressure to remove contaminants from the mixed gas and liquid feed streams going to the reactor catalyst bed. Background of the Invention

[0005] In a fixed - bed hydroprocessing reactor, gas and liquid reactants (e.g., hydrogen and hydrocarbon - containing feeds) flow downward through one or more solid catalyst beds. (See, e.g., U.S. Pat. No. 4,597,854 to Penick). As the reactants flow downward through the reactor catalyst bed, the reactants contact the catalyst material and reactions occur to produce the desired products. The reactor feed stream can also contain fouling and contaminants, which can lead to unwanted deposits, including the formation of organic deposits such as gums.

[0006] Fouling carried in the liquid feed stream can cause fouling on the top distribution plate in the reactor and in the catalyst bed, resulting in an unwanted increase in pressure drop, which limits the performance of the reactor. Unwanted problems can include shorter run lengths, unplanned shutdowns, unused catalyst activity, non - uniform liquid distribution in the catalyst bed, hot - spot formation in the catalyst bed, and increased maintenance, such as distribution plate cleaning. Solutions to mitigate such problems include installing feed filters, bed grading, and in some cases, installing filter plates above the top distribution plate.

[0007] In some cases, the fractionated product has been used in the first catalyst bed to achieve feed contamination removal. While such solutions generally show performance benefits, they reduce the operating run time and / or degrade the on - line performance by occupying valuable reactor volume from the active catalyst volume. Using a graded bed also does not prevent fouling on the top distribution plate.

[0008] The feed filter can also be installed before the reactor inlet, and in some cases, it can be operated at a temperature lower than the temperature of the feed stream entering the reactor. When the filtered liquid feed is subsequently mixed with hydrogen and heated in a furnace before flowing into the reactor inlet, additional organic deposits, such as gums, will form after the feed filter during this heating process. Therefore, it is desirable to have a means to remove sludge and contaminants in the reactor inlet header to protect the top distribution tray and the catalyst bed. Thus, there has been a continuing need for improvements to downflow reactors, including means for removing contaminants from the feed stream. Summary of the Invention

[0009] The present invention relates to a multi-zone filtration device for a downflow hydrotreating reactor. The device provides effective removal of contaminants in the liquid feed stream going to the catalyst bed in the hydrotreating reactor. The filtration device provides effective removal of fines and other contaminants while minimizing the pressure drop in the device. The device is well-suited for retrofit applications and can be used in new reactor designs to achieve efficient removal of feed stream contaminants such that the reactor catalyst bed and reactor internals do not foul and the operating performance of the reactor is improved.

[0010] In addition to minimizing the pressure drop in the filtration device during the operation of removing contaminants, once the filter medium becomes completely fouled, i.e., filled with the removed contaminants, there will be no or minimal additional pressure drop in the device.

[0011] The multi-zone filtration device generally includes a first filtration zone and a second filtration zone. The first zone includes: a top cover having an inner surface and an outer surface, a top cover perimeter, and top cover holes; a liquid-impermeable bottom plate that is generally parallel to the top cover, the liquid-impermeable bottom plate having an inner surface and an outer surface, a bottom plate perimeter, bottom plate holes, and a removable bottom plate hole cover; a first zone protective barrier; an optional bottom plate hole protective barrier; a support structure for the top cover; and a filtration medium that is contained within a first zone filtration medium volume at the top of the bottom plate. The top cover and the bottom plate are spaced apart a distance to define an internal volume of the first zone of the filtration device such that the internal volume includes a filtration medium volume that is located at and adjacent to the top of the inner surface of the bottom plate. The first zone protective barrier holds the filtration medium on the bottom plate and is generally located around the perimeter of the bottom plate and extends from the bottom plate to the top of the filtration medium volume or the bottom surface of the top cover. The first zone bottom plate hole protective barrier (when present) holds the filtration medium within the first zone filtration medium volume on the bottom plate and is generally located around the perimeter of the bottom plate holes and extends from the bottom plate to the top of the filtration medium volume or the bottom surface of the top cover. The support structure for the first zone top cover is generally positioned within the internal volume of the filtration device and includes one or more supports to provide and maintain the separation distance between the top cover and the bottom plate. The bottom plate and the top cover of the first zone, as well as the top cover holes and the bottom plate holes, are all centered about the same central vertical axis. The top cover and the bottom plate have substantially the same area dimensions such that feed stream liquid can flow into the first zone of the filtration device through the top cover and / or through the first zone bottom plate hole protective barrier. The bottom plate hole cover is sized and configured to prevent liquid flow through the first zone bottom plate holes when installed in a downflow reactor and during its operation.

[0012] The second zone includes: a top cover having an inner surface and an outer surface, a top cover periphery, a top cover aperture, and a removable top cover aperture cap; a liquid-impermeable bottom plate generally parallel to the top cover, the liquid-impermeable bottom plate having an inner surface and an outer surface, a bottom plate periphery, and a bottom plate aperture; a bottom plate aperture protective barrier; a support structure for the top cover; a separator on top of the filter medium; and a filter medium contained within a second zone filter medium volume on top of the bottom plate. The second zone top cover and the bottom plate are spaced apart a distance to define an internal volume of the second zone of the filtration device such that the internal volume includes a filter medium volume located on top of and adjacent to the inner surface of the bottom plate and a flow bypass volume located on top of the filter medium volume and adjacent to the inner surface of the top cover. The second zone bottom plate aperture protective barrier holds the filter medium within the second zone filter medium volume on the bottom plate and is generally located around the periphery of the bottom plate aperture and extends from the bottom plate to the top of the filter medium volume or the bottom surface of the top cover. The support structure for the second zone top cover is generally positioned within the internal volume of the filtration device and includes one or more supports to provide and maintain the separation distance between the top cover and the bottom plate. The separator is positioned between the filter medium volume and the flow bypass volume. The separator is generally a thin porous material parallel to both the top cover and the bottom plate. The separator holds the filter medium within the filter medium volume and allows liquid to flow into the filter medium volume. The bottom plate, the top cover, the separator, and the top cover aperture and the bottom plate aperture of the second zone are all centrally positioned about the same central vertical axis as the first zone. The separator generally has substantially the same area dimensions as the bottom plate. The top cover has a smaller area dimension than the bottom plate such that feed stream liquid and gas can flow into a second zone inlet between the periphery of the second zone top cover and the periphery of the bottom plate. The top cover aperture cap is sized to prevent liquid flow through the top cover aperture when installed in a downflow reactor and during its operation.

[0013] Generally, the bottom plates and the top covers of the first zone and the second zone and the separator of the second zone are all centrally positioned about the same central vertical axis. The first zone top cover and the bottom plate have substantially the same area dimensions such that feed stream liquid can flow into the first zone of the filtration device through the top cover and / or through the first zone bottom plate aperture protective barrier. In the second zone, the separator generally has the same area dimensions as the second zone bottom plate. The second zone top cover generally has a smaller area dimension than the bottom plate such that feed stream liquid and gas can flow into the filtration device inlet between the periphery of the top cover and the periphery of the bottom plate.

[0014] The present invention also relates to a downflow hydrotreating reactor comprising a multi-zone filtration device, and a method for removing contaminants from a liquid feed stream in such a reactor. The method generally comprises passing a feed stream comprising liquid and gas through the filtration device mounted at the top of the reactor to a downflow catalytic hydrotreating reactor, wherein the liquid component of the feed stream is directed through a filter medium volume contained in a first zone of the filtration device and a filter medium volume contained in a second zone of the filtration device. The feed stream liquid passes through the filter medium contained in the filter medium volumes of the first and second zones, while the feed stream gas passes through a flow bypass volume of the second zone of the filtration device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figures 1 to 11 Representative views of a multi-zone filtration device according to one or more embodiments of the present invention are provided. The scope of the present invention is not limited by these representative drawings and should be understood to be defined by the appended claims.

[0016] Figure 1 A side view of an embodiment of the first zone of the filtration device of the present invention is shown.

[0017] Figure 2 A side view of an embodiment of the second zone of the filtration device of the present invention is shown.

[0018] Figure 3 A side view of an embodiment of the two-zone filtration device of the present invention mounted at the top of a reactor is shown, wherein a side cross-section of the reactor wall and an existing distribution tray (also referred to herein as a perforated tray) is also shown.

[0019] Figure 4 Shows the two-zone filtration device in Figure 2 the same view as in, wherein the flow paths of the feed stream liquid and gas are also shown.

[0020] Figure 5 A 3 / 4 cross-sectional view of the lower section of the second zone of the filtration device is shown, wherein the top cover and the separator have been removed (an existing tray below the filtration device is also shown).

[0021] Figure 6 Shows the 3 / 4 cross-sectional view of the second zone of the filtration device as in Figure 5 wherein the separator is in place.

[0022] Figure 7 Shows the 3 / 4 cross-sectional view of the second zone of the filtration device as in Figure 6 wherein the top cover is in place.

[0023] Figure 8 Shows a 3 / 4 cross-sectional view of a two-zone filtration device, which shows an open view of the top first zone (circular manhole opening) of the filtration device with the top cover removed and the lower second zone.

[0024] Figure 9 Shows a 3 / 4 cross-sectional view of a two-zone filtration device, which shows a view of the top first zone (circular manhole opening) of the filtration device with the top cover installed and the lower second zone.

[0025] Figure 10 Shows a 3 / 4 cross-sectional view of a two-zone filtration device, which shows an open view of the top first zone (rectangular manhole opening) of the filtration device with the top cover removed and the lower second zone.

[0026] Figure 11 Shows a 3 / 4 cross-sectional view of a two-zone filtration device, which shows a view of the top first zone (rectangular manhole opening) of the filtration device with the top cover installed and the lower second zone. Detailed Description

[0027] Based on the detailed description provided herein, specific embodiments and benefits are obvious. However, it should be understood that the detailed description, the drawings, and any specific examples, although indicating beneficial embodiments (including some preferred embodiments), are only intended for illustrative purposes and are not intended to limit the scope of the present invention.

[0028] The present invention relates to a multi-zone filtration device for a downflow hydrotreating reactor. The device includes a first filtration zone and a second filtration zone. The first zone includes: a top cover having an inner surface and an outer surface, a top cover perimeter, and a top cover hole; a bottom plate substantially parallel to the top cover, the bottom plate having an inner surface and an outer surface, a bottom plate perimeter, a bottom plate hole, and a removable bottom plate hole cover; a first zone protective barrier; an optional bottom plate hole protective barrier; a support structure for the top cover; and a filter medium accommodated within the first zone filter medium volume of the device and on top of the bottom plate. The second zone includes: a top cover having an inner surface and an outer surface, a top cover perimeter, a top cover hole, and a removable top cover hole cover; a liquid-impermeable bottom plate substantially parallel to the top cover, the liquid-impermeable bottom plate having an inner surface and an outer surface, a bottom plate perimeter, and a bottom plate hole; a bottom plate hole protective barrier; a support structure for the top cover; a separator on top of the filter medium; and a filter medium accommodated within the second zone filter medium volume on top of the bottom plate.

[0029] The top cover and bottom plate of the first zone are separated by a distance, thereby defining the internal volume of the first zone of the filtration device, such that the internal volume includes the volume of the filter medium located at the top of the inner surface of the bottom plate and adjacent to the inner surface of the bottom plate. The first zone protective barrier holds the filter medium on the bottom plate. The protective barrier is typically located around the perimeter of the bottom plate and extends from the bottom plate to the top of the filter medium volume or the bottom surface of the top cover, and holds the filter medium in the first zone filter medium volume on the bottom plate. The first zone bottom plate hole protective barrier (when present) also holds the filter medium within the first zone filter medium volume on the bottom plate. The hole protective barrier is typically located around the perimeter of the bottom plate hole and extends from the bottom plate to the top of the filter medium volume or the bottom surface of the top cover. The support structure for the first zone top cover is located within the internal volume of the filtration device and includes one or more supports to provide and maintain the separation distance between the top cover and the bottom plate. The bottom plate and top cover of the first zone, as well as the top cover holes and bottom plate holes, are centered around the same central vertical axis. The top cover and bottom plate have substantially the same area dimensions such that the feed stream liquid can flow into the first zone of the filtration device through the top cover and / or through the first zone bottom plate hole protective barrier. The bottom plate hole cover is sized and configured to prevent liquid flow through the first zone bottom plate holes when installed in a downflow reactor and during its operation.

[0030] The top cover and bottom plate of the second zone are separated by a distance, thereby defining the internal volume of the filtration device. The second zone internal volume includes the volume of the filter medium located at the top of the inner surface of the bottom plate and adjacent to the inner surface of the bottom plate, and the flow bypass volume located at the top of the filter medium volume and adjacent to the inner surface of the top cover. The bottom plate hole protective barrier holds the filter medium within the second zone filter medium volume on the bottom plate. The bottom plate hole protective barrier is typically located around the perimeter of the bottom plate hole and extends from the bottom plate to the top of the filter medium volume or the bottom surface of the top cover. The support structure for the top cover is located within the internal volume of the filtration device and includes one or more supports to provide and maintain the separation distance between the top cover and the bottom plate. A separator is positioned between the filter medium volume and the flow bypass volume. The separator is typically a thin porous material that is parallel to both the top cover and the bottom plate. The separator holds the filter medium within the filter medium volume and allows liquid to flow into the filter medium volume. The bottom plate, top cover, separator, as well as the top cover holes and bottom plate holes of the second zone are centered around the same central vertical axis as in the first zone. The separator typically has substantially the same area dimensions as the bottom plate. The second zone top cover has a smaller area dimension than the bottom plate such that the feed stream liquid and gas can flow into the second zone inlet between the perimeter of the second zone top cover and the perimeter of the bottom plate. The second zone top cover hole cover is sized to prevent liquid flow through the top cover holes when installed in a downflow reactor and during its operation.

[0031] The first and second zone containment barriers and the aperture containment barrier can generally be liquid permeable over the entire width and height of the barrier. In some embodiments, the containment barrier can be liquid permeable in a portion of the width and / or height of the barrier while being liquid impermeable (or less liquid permeable) to allow liquid to be retained within either or both of the first zone filtration volume and the second zone filtration volume. The device does not need to or does not have to include an outer perimeter second zone containment barrier located around the perimeter of the bottom plate and extending from the bottom plate to the top of the filtration media volume or the bottom surface of the top cover. By using an outer perimeter containment element, the filtration media does not need to be contained around the perimeter of the second zone bottom plate.

[0032] Generally, the bottom plate, top cover, and separator of the second zone are centered around the same central vertical axis. The separator typically has the same area dimensions as the bottom plate. The second zone top cover typically also has a smaller area dimension than the bottom plate such that feed stream liquid and gas can flow into the filtration device inlet between the perimeter of the top cover and the perimeter of the bottom plate. Although the filtration device does not have to be limited to a particular shape or size, in most cases, the device will match the cross-sectional shape of a new or existing reactor; typically, the shape of the filtration device is circular such that each of the top cover, bottom plate, and separator is circular and sized to correspond to the internal dimensions of the reactor and fit horizontally within the headspace of the reactor. In the case where the device is generally circular, the distance between the outer perimeter of the top cover (also referred to herein as the top deflector) and the outer perimeter of the bottom plate is an annular region around the outside of the second zone through which feed stream liquid and gas that has been diverted to the outside of the reactor enters the second zone of the device and flows inwardly towards the bottom plate apertures.

[0033] The top covers and bottom plates of the first and second zones and the separator of the second zone can also be formed as a plurality of segments that together form the respective top cover, bottom plate, or separator. Using segments for certain device components such as the top cover, bottom plate, and separator allows the segments to be placed within or removed from the reactor through reactor internal access locations such as manholes, thus facilitating installation and maintenance.

[0034] A variety of support structures can be used to support the first zone and / or the second zone top cover or sections of the top cover, and to provide a distance between the top cover and the bottom plate. For example, a plurality of transverse members (such as trusses) spanning the cross-sectional distance between the walls of the reactor can be used to support the top cover of the second zone. The support structure, or more specifically the transverse members, are typically supported by structures within the reactor, such as by support members resting on top of existing trays, or by other connections to the reactor or reactor internal components. In some cases, for example when using transverse members, the support structure can also be used to support the separator or sections of the separator. The support structure can also support the bottom plate or sections of the bottom plate. In one embodiment, the support structure includes a plurality of transverse member trusses that span the distance from one cross-section of the reactor wall across the reactor cross-section to the other side of the reactor, such that the bottom plate is supported on the lower portion of the truss, the separator is supported on the middle portion of the truss, and the top cover is supported by the top of the truss. In cases where each of the top cover, bottom plate, and separator includes sections of corresponding components, each section can be configured and arranged to be supported within the space between the trusses.

[0035] Generally, the filtration device can use the first zone and the second zone, or any arrangement of any number of zones, within the device. However, in practice, the height available at the top of a downflow reactor may limit the device to two or three zones. In one embodiment, for example, the first zone and the second zone can be arranged in a two-zone configuration, where the first zone is positioned on top of the second zone.

[0036] Depending on the arrangement of the first zone and the second zone, one zone can be stacked on top of the other zone, thereby relying on the support trusses for the bottom zone to also support one or more upper zones. For example, in an embodiment where the filtration device is a two-zone device with a first zone located on top of a second zone, the support trusses can be used for the bottom second zone. Then, the upper first zone can utilize the support provided by the second zone, such that the internal support required for the first zone can benefit from reduced load requirements.

[0037] The separator of the second zone typically defines the region between the filtration media volume and the bypass flow volume within the second zone of the filtration device. Typically, the separator is a thin porous material that functions to hold the filtration media in place and within the filtration media volume. A variety of materials can be used, such as wire-based materials, as well as grids, meshes, screens, or perforated metal or plates. Although not particularly limited, the separator or sections thereof can be slightly rigid to assist with installation and to help maintain its placement during operation. In some embodiments, the separator can be an optional component and may not have to be included in the device, for example if the separator is not needed to hold the filtration media contained within the filtration media volume.

[0038] The bottom plate holes in the second zone allow the feed stream liquid and gas to pass through the filtration device and flow to other downward locations within the device or reactor, e.g., to a distribution tray below the filtration device. The size of the holes can vary and there is no particular limitation (except to avoid introducing flow restrictions and to allow effective use of the filtration volume). The bottom plate holes can be shaped to provide a manway passage to internal components of the reactor below the filtration device.

[0039] The hole covers for the first zone bottom plate and the second zone top cover can be formed from a variety of materials, including the materials used for the respective plates. While not limited thereto, the covers are typically made of a liquid-impermeable material, such as the same metal used for the plates. The covers are generally removable to allow access to the interior of the filtration device and to allow the manway passage to internal components within the downflow reactor.

[0040] A variety of filtration media can be used to provide pollutant removal within the filtration volumes of the first and second zones. While suitable materials typically include any materials known in the art, absorbent materials that are convenient for loading, maintenance, and removal will typically be used. Such materials are commercially available and are typically provided in pellet or other common shapes for use in hydrotreating reactors. In some cases, pelletized absorbent filtration media having a nominal length in the range of about 5 mm to about 20 mm can be used. The filtration media used in the first and second zones can be the same or different and are generally selected according to the filtration requirements of each zone.

[0041] The present invention also relates to the use of the filtration device in a hydrotreating system and a hydrotreating reactor system using the filtration device. In certain embodiments, the filtration device can advantageously be used in a downflow hydrotreating reactor, e.g., as a pollutant removal tray located internally at the top of such a reactor.

[0042] In an embodiment of the present invention, as Figures 1 to 11 shown, the filtration device can have a central cross-sectional view as shown for the first zone in Figure 1 and the second zone in Figure 2 . In Figure 1 , the bottom plate 10a of the first zone forms the lower portion of the first zone of the filtration device, while the top is formed by the top cover 20a of the first zone. The bottom plate 10a has openings called bottom plate holes, which are typically located at the center of the bottom plate to allow passage through the device, e.g., a manway passage to a distribution tray below the filtration device. As Figure 1As shown, during normal downflow reactor operation, a bottom plate hole cover 12a is installed within or above the holes. A support or lateral member, which can be a truss 30a, is shown supporting the bottom plate and the top cover. A filtration volume 15a (first zone) is located between the bottom plate 10a and the top cover 20a and is also located between the lateral members 30a (also referred to herein as supports, support members, and trusses). The support can have any suitable arrangement or structure for supporting the top cover. A protective barrier 55a is located at the outer edge perimeter of the bottom plate and around the perimeter to contain the filter medium on the bottom plate. A hole protective barrier 50a surrounds the bottom plate holes within the interior or center of the filtration device. The filter medium 60a is contained within the first zone filtration medium volume 15a. The top cover 20a can also have an opening generally corresponding to the bottom plate holes (as shown) to allow access to the interior of the filtration device. Although not necessary, the bottom plate 10a and the top cover 20a can each be provided in the form of more than one section on top of and between the support members 30a. In some cases, one or more of the bottom plate 10a and the top cover 20a can be provided as an undivided integral part of the filtration device.

[0043] In Figure 2 it, a second zone bottom plate 10b forms the lower part of the second zone of the filtration device, while the top is formed by a second zone top cover 20b. The bottom plate 10b has openings called bottom plate holes, which are typically located at the center of the bottom plate to allow access through the device, such as a manhole passage to a distribution plate below the filtration device. As Figure 2 shown, during normal downflow reactor operation, a top cover hole cover 12b is installed within or above the holes. A support or lateral member, which can be a truss 30b, is shown supporting the bottom plate and the top cover. A separator 40b located between the lower (second zone) filtration volume 15b and the upper flow bypass volume 25b divides the interior volume of the second zone into two flow segments and is also supported by the lateral member 30b (also referred to herein as supports, support members, and trusses). The filtration volume 15b is located between the bottom plate 10b and the top cover 20b and is also located between the lateral members 30b. The support can have any suitable arrangement or structure for supporting the top cover. A hole protective barrier 50b surrounds the bottom plate holes within the interior or center of the filtration device. The filter medium 60b is contained within the filtration medium volume 15b. The top cover 20b can also have an opening generally corresponding to the bottom plate holes to allow access to the interior of the filtration device. Although not necessary, the bottom plate 10b and the top cover 20b can each be provided in the form of more than one section on top of and between the support members 30b. In some cases, one or more of the bottom plate 10b and the top cover 20b can be provided as an undivided integral part of the filtration device.

[0044] In one embodiment, the first zone and the second zone can be combined in a dual zone filtration device, wherein the first zone is directly on top of the second zone. In this arrangement, only one of the bottom plate of the first zone and the top cover of the second zone needs to be used. For example, the bottom plate hole cover 12a and the top cover hole cover 12b of the first zone can be simplified in terms of configuration and assembly to use only one hole cover instead of two hole covers.

[0045] Figure 3 The embodiment of the dual zone filtration device installed in the downflow reactor is shown. Figure 1 and Figure 2 Same central cross-section view. Figure 1 and Figure 2 The reference numerals for the features described in Figure 3 As shown, the filtration device may be mounted at the top of the reactor and positioned between the side walls of the reactor housing 110 and below the intercepting tank 100 (eg, if present). Figure 3 One embodiment of a possible installation of the apparatus within a downflow reactor is shown, but other configurations may be used. A second zone top cover 20b and aperture cover 12b are shown, wherein the top cover is used in place of the bottom plate 10a of the first zone. Figure 3 It also shows Figure 1 and Figure 2 The other elements noted in the preceding description of are incorporated herein for reference and completeness. For illustration purposes, Figure 3 Also included is a distribution plate (also referred to as a perforated plate) 70, a spacer ring 80 positioned between the distribution plate 70 and the bottom plate 10, and a sealing ring 90 that provides a seal between the bottom plate and the reactor sidewall. The distribution plate 70, the spacer ring 80, and the sealing ring 90 are not essential components of the filtration device or the installation of the device within the reactor, and are provided herein to illustrate possible installation embodiments.

[0046] Figure 4 In one embodiment, Figure 3 The same center cross-sectional view, in this embodiment, of a dual zone filter device mounted below a catch basin 100 in a downflow reactor, to illustrate a simplified view of general liquid and gas flow paths. The liquid 120 and gas 130 flow paths are generally shown as passing through the first zone filter media 15a, the second zone filter media 15b, and the flow bypass volume 25b within the filter media volume of the second zone, respectively. As shown, the flow of the feed stream liquid is from the reactor sidewall radially outward in the first zone and radially inward in the second zone, flowing through the second zone filter device inlet and the second zone filter media volume, and then flowing through the protective barrier and the floor hole located in the center of the filter device.

[0047] Figure 5A 3 / 4 sectional isometric view of an embodiment of the second zone of the filtration device is shown, where the top cover and the separator are removed so that the internal arrangement of the lateral member 30b support and the protective barrier 50b can be easily seen. As shown, the bottom plate hole located at the center of the bottom plate 10b provides a manhole passage to the internal components of the reactor below the filtration device. Although the lateral member 30b is shown as a truss support, suitable alternative support members can be used.

[0048] Figure 6 Shows a 3 / 4 sectional isometric view according to Figure 5 in which the second zone separator 40b (also known as the compaction screen) is installed and supported at an intermediate position on the lateral member 30b. The separator generally has the same area size as the bottom plate and includes a central opening hole corresponding to the opening of the bottom plate hole. Also shown is the top support of the lateral member 30b that supports the top cover when installed.

[0049] Figure 7 Shows a 3 / 4 sectional isometric view according to Figure 5 and Figure 6 in which the top cover 20b (also known as the deflector plate) is installed and supported at the top of the lateral member 30b. The top cover 20b is shown with the hole cover (central manhole panel) removed. The hole cover ( Figure 1 12a in Figure 2 or 12b in Figure 4 , also known as the manhole panel) is installed for normal reactor operation and can be removed to provide access for maintenance. For reference, other components are also shown as in Figure 5 , including for example the second zone separator 40b.

[0050] Figure 8 Shows a 3 / 4 sectional isometric view in which the support member 30a of the first zone is installed on top of the top cover 20b of the second zone, and the top cover serves as the bottom plate of the first zone. It should be noted that Figure 1 the bottom plate 10a of the first zone in Figure 2 and the top cover 20b of the second zone in Figure 1 can both be used, respectively for the first zone and the second zone, or the bottom plate 10a or the top cover 20b can be used alone instead of using both. Also shown are the peripheral protective barrier 55a and the internal hole protective barrier 50a. The top cover hole cover (manhole panel) 12b is shown at the center of the first zone, aligned with the manhole passage (i.e., the second zone hole) in the second zone. It should be noted that the hole cover 12a as shown in Figure 2 can also be used together with or in place of the hole cover 12b as shown in

[0051] Figure 9shows a view in accordance with Figure 8 in which the first zone top cover 20a is installed. Figure 8 and Figure 9 depict a circular central manhole passage area defined by the hole protection barrier 50a. Also shown for the first zone are the first zone hole cover 12a (which, as shown, may be the same as the second zone top cover hole cover 12b), the bottom plate perimeter 14a, the bottom plate hole 16a, the top cover perimeter 24a, and the top cover hole 26a, and also shown for the second zone are the bottom plate perimeter 14b, the bottom plate hole 16b, the top cover perimeter 24b (which, as shown, may be the same as the first zone bottom plate perimeter 14a), the top cover hole 26b (which, as shown, may be the same as the first zone bottom plate hole 16a), and the top cover hole cover 12b (which, as shown, may be the same as the first zone hole cover 12a). Also shown is the second zone separator 40b.

[0052] Figure 10 and Figure 11 shows a view corresponding to Figures 8 to 9 but having a rectangular central manhole passage area and first zone components, the rectangular central manhole passage area extending through the first zone top cover 20a, where the protection barrier 50a surrounds the manhole passage hole. Figures 1 to 9 Certain features identified in Figure 10 and described above are also incorporated herein for reference and completeness, including the first zone bottom plate 10a (which may be the same as the second zone top cover 20b), the first zone hole cover 12a (which, as shown, may be the same as the second zone top cover hole cover 12b), the first zone bottom plate perimeter 14a (which, as shown, may be the same as the second zone top cover perimeter 24b), the top cover perimeter 24a, and the support member 30a. Also shown is a section of the first zone filtration volume 15a ( Figure 10 ). Figure 11 shows the top cover hole 26a and the bottom plate hole 16b, as Figure 9 in

[0053] The multi-zone filtration device of the present invention (including the specific embodiments described herein) provides certain benefits and improvements in hydrotreating applications, including: minimizing fouling and the arrival of small particles or fines to the catalyst bed and reactor internals below the filtration device; reducing the increase in pressure drop throughout the operation of the reactor, thereby allowing for full or extended run operations; minimizing additional pressure drop in the reactor, even when the filter bed is completely fouled, i.e., filled with contaminants; and potentially reducing the amount of grading material required at the top of the catalyst bed, thereby increasing the volume of active catalyst in the reactor.

[0054] The present disclosure is not limited in terms of the specific embodiments described in this application, which are intended to be illustrative of the various aspects. Obviously, many modifications and variations can be made without departing from its spirit and scope. In addition to the methods and systems enumerated herein, functionally equivalent methods and systems within the scope of the present disclosure will be apparent from the foregoing representative description. These modifications and variations are intended to fall within the scope of the appended representative claims. The present disclosure is limited only by the terms of the appended representative claims and the full scope of the equivalents to such representative claims. It should also be understood that the terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting.

[0055] The foregoing description and the associated embodiments are presented for illustrative purposes only. It is not exhaustive and does not limit the invention to the exact forms disclosed. Those skilled in the art will appreciate from the foregoing description that modifications and variations can be made, or can be obtained by practicing the disclosed embodiments, in accordance with the above teachings. For example, in some cases, the steps described need not be performed in the same order or with the same degree of separation as discussed. Similarly, various steps or features can be omitted, repeated, or combined as needed to achieve the same or similar purposes. Accordingly, the invention is not limited to the embodiments described above, but is instead defined by the appended claims in accordance with their full scope of equivalents.

[0056] In the foregoing specification, various preferred embodiments have been described with reference to the accompanying drawings. However, it will be apparent that various modifications and variations can be made thereto, and additional embodiments can be implemented, without departing from the broader scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

[0057] To the extent permitted, all publications, patents, and patent applications cited in this application are hereby incorporated by reference in their entirety, provided that such disclosure is not inconsistent with the present invention.

Claims

1. A multi-zone filtration device for removing contaminants from a liquid feed stream in a downflow catalytic hydrotreating reactor, the filtration device comprising a first filtration zone and a second filtration zone; The first region includes: A first zone top cover having an inner surface and an outer surface, a first zone top cover perimeter, and a top cover hole; A first zone liquid-impermeable bottom plate substantially parallel to the top cover, the first zone liquid-impermeable bottom plate having an inner surface and an outer surface, a bottom plate perimeter, a bottom plate hole, and a removable bottom plate hole cover, wherein the first zone top cover and the bottom plate are spaced apart by a distance to define an inner volume of the first zone of the filtration device, and wherein the inner volume of the first zone includes a first zone filtration media volume located at and adjacent to the top of the inner surface of the first zone bottom plate; A first zone protective barrier for holding the filtration media within the first zone filtration media volume on the bottom plate, located around the perimeter of the bottom plate and extending from the bottom plate to the top of the filtration media volume or the bottom surface of the top cover; An optional first zone bottom plate hole protective barrier for holding the filtration media on the bottom plate, located around the perimeter of the top cover and the bottom plate hole, and extending from the bottom plate to the top of the filtration media volume or the inner surface of the top cover; A first zone support structure for the first zone top cover, the first zone support structure positioned within the inner volume of the first zone of the filtration device and including one or more support members to provide and maintain the separation distance between the top cover and the bottom plate; And Filtration media contained within the first zone filtration media volume; Wherein the bottom plate and the top cover of the first zone, as well as the top cover hole and the bottom plate hole, are centered about the same central vertical axis, the top cover and the bottom plate having substantially the same area dimensions such that feed stream liquid can flow into the first zone of the filtration device through the top cover and / or through the first zone bottom plate hole protective barrier, and the bottom plate hole cover is sized to prevent liquid flow through the bottom plate hole during reactor operation when installed; The second zone includes: a second zone top cover having an inner surface and an outer surface, a second zone top cover perimeter, a top cover hole, and a removable top cover hole cover; A second zone liquid-impermeable bottom plate substantially parallel to the top cover, the second zone liquid-impermeable bottom plate having an inner surface and an outer surface, a bottom plate perimeter, and a bottom plate hole, wherein the top cover and the bottom plate are spaced apart by a distance to define an inner volume of the second zone of the filtration device, and wherein the inner volume of the second zone includes a second zone filtration media volume located at and adjacent to the top of the inner surface of the second zone bottom plate, and a flow bypass volume located at the top of the second zone filtration media volume and adjacent to the inner surface of the top cover; A second zone support structure for the second zone top cover, the second zone support structure being positioned within the internal volume of the second zone of the filtration device and including one or more support members to provide and maintain a separation distance between the top cover and the bottom plate; A separator, the separator being positioned between the second zone filtration media volume and the flow bypass volume, wherein the separator is generally thin and parallel to both the second zone top cover and the bottom plate, having a top surface and a bottom surface, containing the filtration media within the second zone filtration media volume, and allowing liquid to flow into the second zone filtration media volume during downflow reactor operation; A second zone bottom plate hole protection barrier for retaining the filtration media within the second zone filtration media volume on the bottom plate, located around the perimeter of the bottom plate holes and extending from the bottom plate to the top of the filtration media volume or the bottom surface of the separator; and, Filtration media, the filtration media being contained within the second zone filtration media volume; Wherein the bottom plate, the top cover, the separator, and the top cover holes and the bottom plate holes of the second zone are all centered around the same central vertical axis as in the first zone, the separator generally having substantially the same area size as the bottom plate, and the top cover having a smaller area size than the bottom plate, such that feed stream liquid and gas can flow into the second zone inlet between the perimeter of the second zone top cover and the perimeter of the bottom plate, and the top cover hole covers are sized to prevent liquid flow through the top cover holes during reactor operation when installed.

2. The filtration device according to claim 1, wherein the device is a two-zone filtration device having a first zone located on top of and adjacent to a second zone, and wherein the device is configured to allow liquid to flow through the first zone during operation when installed in a downflow reactor, and then allow liquid and gas to flow through the second zone.

3. The filtration device according to claim 1 or 2, wherein the first zone bottom plate serves as the second zone top cover, or the second zone top cover serves as the first zone bottom plate.

4. The filtration device according to any one of claims 1 to 3, wherein the first zone holes and the second zone holes are centered around the same vertical axis as in the first zone and the second zone, and are aligned when installed in a downflow reactor to provide a manhole reactor passage through the filtration device.

5. The filtration device according to any one of claims 1 to 4, wherein the first zone includes a bottom plate hole protection barrier.

6. The filtration device according to any one of claims 1 to 5, wherein the first zone protection barrier, the first zone hole protection barrier, and / or the second zone hole protection barrier are liquid-permeable.

7. The filtration device according to any one of claims 1 to 6, wherein the device and each of the top cover, the bottom plate, and the separator are generally circular in size and are sized to be horizontally assembled within the top space of a downflow reactor.

8. The filtration device according to any one of claims 1 to 7, wherein the first zone has a smaller area dimension than the second zone to define a first zone outlet region around the perimeter of the first zone, and when installed in a downflow reactor, during operation, the feed stream liquid flows outwardly through the first zone outlet region through the first zone protective barrier.

9. The filtration device according to any one of claims 1 to 8, wherein the second zone top cover has a smaller area dimension than the second zone bottom plate to define a second zone inlet region around the perimeter of the second zone, and when installed in a downflow reactor, during operation, the feed stream liquid and gas enter the second zone through the second zone inlet region and flow inwardly towards the second zone bottom plate holes.

10. The filtration device according to any one of claims 1 to 9, wherein one or more of the first zone and / or the second zone top cover, bottom plate or separator include a plurality of segments that together form the respective top cover, bottom plate or separator such that the segments can be placed inside the downflow reactor or removed from the downflow reactor through the reactor internal channel location.

11. The filtration device according to any one of claims 1 to 10, wherein the support structure of the first zone and / or the second zone includes a plurality of transverse members to provide support for the top cover or a segment of the top cover, the separator or a segment of the separator, the bottom plate or a segment of the bottom plate, or a combination thereof.

12. The filtration device according to claim 11, wherein the transverse members supporting the first zone include supports extending from the bottom plate to the top cover or a segment of the top cover.

13. The filtration device according to claim 11, wherein the transverse members supporting the second zone include top supports and intermediate supports between the top and bottom of the transverse members, wherein the top supports support the second zone top cover or a segment of the second zone top cover, and the intermediate supports support the separator or a segment of the separator.

14. The filtration device according to any one of claims 1 to 13, wherein the first zone top cover and / or the second zone separator includes wire, mesh, netting, screen, or perforated metal material or plate that holds the filter medium within the filter medium volume.

15. The filtration device according to any one of claims 1 to 14, wherein the first zone protective barrier and / or the first zone and / or second zone bottom plate hole protective barrier includes wire, mesh, netting, screen, or perforated metal material or plate that holds the filter medium within the filter medium volume and allows the feed stream liquid to flow through the filter medium volume during operation when installed in a downflow reactor.

16. The filtration device according to any one of claims 1 to 15, wherein the filter medium in the first zone and / or the second zone includes particulate filter absorbent material having a nominal size in the range of about 5 mm to about 20 mm.

17. The filtration device according to any one of claims 1 to 16, wherein the second zone does not include a protective barrier extending from the bottom plate to the top of the filtration medium volume or the bottom surface of the top cover around the periphery of the bottom plate, or wherein the filtration medium is not received around the periphery of the bottom plate, or a combination thereof.

18. A downflow catalytic hydrotreating reactor comprising the filtration device according to any one of claims 1 to 17.

19. A method for removing contaminants from a liquid feed stream in a downflow catalytic hydrotreating reactor, the method comprising passing the feed stream to the downflow catalytic hydrotreating reactor through a filtration device according to any one of claims 1 to 17 mounted at the top of the reactor, wherein the liquid feed stream passes through the filtration medium within the filtration medium volume of the first zone of the filtration device and through the filtration medium within the filtration medium volume of the second zone.

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