Method and system for alkylate production with a multizone alkylation reactor

Abstract

A method and system for alkylate production involving a multizone alkylation reactor. The multizone alkylation reactor includes a plurality of alkylation zones spaced apart in a vertically series configuration, and a partition plate that divides the plurality of alkylation zones into at least two mechanically separated catalyst volumes.

Description

Detailed Description of the Invention

[0001] Inventors Rajeev Ranjan and Anubhav Kapil. [Cross - Reference to Related Applications] This application claims priority to U.S. Patent Application No. 18336936, filed on June 16, 2023. The content of this document is hereby incorporated by reference in its entirety into this specification. [Technical Field]

[0002] This disclosure relates to embodiments of a multi - zone alkylation reactor in an alkylate production system and methods of using the same. These systems and methods can increase the amount of alkylate produced and can also reduce the amount of recycle flow or recycle gas flow used to the alkylation reactor. [Background Art]

[0003] In refining operations, there has been a struggle to meet the high demand for higher octane fuels. Technologies such as KBR's solid acid alkylation technology (K - SAAT™ technology) convert olefins to alkylates using an isobutane solvent within an alkylation reactor. The alkylation process uses a fixed - bed catalyst - supported reaction to convert an isoparaffin solvent and an olefin to a higher molecular weight paraffin. In a fixed - bed reactor, the primary reaction between an olefin and an isoparaffin competes with the secondary reaction between olefins. The rate constant of the secondary (olefin - to - olefin) reaction is two orders of magnitude higher than that of the primary reaction. Therefore, it is desirable to maintain the isobutane - to - olefin (I / O) ratio at least two orders of magnitude higher. To maintain this relatively high I / O ratio, a large amount of the alkylate - containing stream from the alkylation reactor is recycled back to the alkylation reactor. However, this large - scale recycling and the associated pressure drop reduce the potentially processable amount of alkylate. [Summary of the Invention]

[0004] This specification provides systems and methods that address these shortcomings of the art and offer other additional or alternative advantages. The disclosures herein provide a multizone alkylation reactor for alkylate production and several embodiments of the system and methods.

[0005] Embodiments of the alkylation system include a multizone alkylation reactor. This multizone alkylation reactor includes a plurality of alkylation zones spaced apart in a vertical series configuration. The multizone alkylation reactor includes at least one vertical partition plate that divides the plurality of alkylation zones into at least a first mechanically separated catalyst volume and a second mechanically separated catalyst volume. In addition, the multizone alkylation reactor includes an isobutane inlet configured to supply an isobutane flow to the first mechanically separated catalyst volume and at least one olefin supply inlet configured to supply an olefin-containing flow to the plurality of alkylation zones, thereby generating an alkylate flow. The multizone alkylation reactor further includes a first alkylate product fluid passage that transports the alkylate flow from the first mechanically separated catalyst volume to the second mechanically separated catalyst volume.

[0006] Embodiments of the alkylation system include a multizone alkylation reactor equipped with a recirculation pump. The multizone alkylation reactor comprises a plurality of alkylation zones spaced apart in a vertical series configuration, a vertical partition plate dividing the plurality of alkylation zones into two mechanically separated catalyst volumes, a plurality of olefin supply inlets arranged thereto to supply an olefin-containing flow to each of the plurality of alkylation zones in the two mechanically separated catalyst volumes, an isobutane inlet for supplying isobutane to a first alkylation zone in the first mechanically separated catalyst volume, and a fluid flow of alkylate flow through the plurality of alkylation zones in the first mechanically separated catalyst volume. The system includes a first set of fluid passages configured for movement, a first set of alkylate product fluid passages for transporting the alkylate flow from the last alkylation zone in the first set of catalyst volumes to the first set of alkylation zones in the second set of catalyst volumes, a second set of fluid passages configured for the fluid flow of the alkylate flow through a set of alkylation zones in the second set of catalyst volumes, and a second set of alkylate product fluid passages for transporting the alkylate flow from the last alkylation zone in the second set of catalyst volumes to a recirculation pump. The fluid flow may be downward or upward through the set of alkylation zones. The olefin-containing flow contains olefins, such as ethylene and propylene, and lighter components, such as hydrogen and methane. The alkylate flow contains alkylates produced by the reaction of olefins with isobutane in the olefin-containing flow. The alkylates include mixtures of high-octane branched-chain paraffinic hydrocarbons. Each of the mechanically separated catalyst volumes may be configured as a hydraulically sealed reaction chamber. Each of the multiple alkylation zones contains a solid acid alkylation catalyst.The recirculation pump is configured to receive the alkylate flow from a second alkylate product fluid passage, to direct the first portion of the alkylate flow to further processing to produce a concentrated alkylate product containing high-octane branched-chain paraffinic hydrocarbons, and to recirculate the second portion of the alkylate flow to a first mechanically separated catalyst volume, thereby maintaining a desired ratio of isobutane to olefin. In certain embodiments, this ratio is in the range of about 300:1 to about 500:1. The flow rate of the recirculation pump can be reduced by at least 50 percent compared to the recirculation pump of a conventional alkylation reactor.

[0007] Another embodiment of an alkylation system for increasing alkylate products includes a multizone alkylation reactor and a recirculation pump. One embodiment includes a deisobutane column in fluid contact with the recirculation pump. For example, a multizone alkylation reactor includes a plurality of alkylation zones spaced apart in a vertical series configuration, at least one vertical baffle plate dividing the plurality of alkylation zones into at least two mechanically separated catalyst volumes, a plurality of olefin feed inlets arranged to supply an olefin-containing flow to each of the plurality of alkylation zones in the at least two mechanically separated catalyst volumes, an isobutane inlet for supplying isobutane to a first alkylation zone in the first mechanically separated catalyst volume, and an alkylate flow through the plurality of alkylation zones in the first mechanically separated catalyst volume. The system includes a first set of fluid passages configured for the fluid flow of a rate flow, a first set of alkylate product fluid passages for transporting the alkylate flow from the last alkylation zone in a first mechanically separated catalyst volume to the first alkylation zone in a second mechanically separated catalyst volume, a second set of fluid passages configured for the fluid flow of the alkylate flow through a set of alkylation zones in a second mechanically separated catalyst volume, and a second set of alkylate product fluid passages for transporting the alkylate flow from the last alkylation zone in the second mechanically separated catalyst volume to a recirculation pump. The alkylate flow contains alkylates produced by the reaction of olefins and isobutane in an olefin-containing flow. The fluid flow may be downward or upward through the set of alkylation zones. The recirculation pump is configured to receive the alkylate flow from a second alkylate product fluid passage, guide a first portion of the alkylate flow to a deisobutane column, and recirculate a second portion of the alkylate flow to a first mechanically separated catalyst volume, thereby maintaining a desired molar ratio of isobutane to olefin. In certain embodiments, this ratio is in the range of approximately 300:1 to approximately 500:1.The deisobutane column is configured to receive a first portion of the alkylate flow from a recirculation pump and to separate the first portion of the alkylate flow into (i) a recycled isobutane flow supplied to a first mechanically separated catalyst volume, (ii) a normal butane flow, and (iii) a product flow containing a mixture of high-octane branched-chain paraffinic hydrocarbons.

[0008] Embodiments include a method for producing alkylates involving a multizone alkylation reactor. For example, this multizone alkylation reactor may include two mechanically separated catalyst volumes having a first and a second plurality of alkylation zones packed with an alkylation catalyst; a first plurality of fluid passages configured for downward or upward fluid flow through the first plurality of alkylation zones in the first mechanically separated catalyst volume; and a second plurality of fluid passages configured for downward or upward fluid flow through the second plurality of alkylation zones in the second mechanically separated catalyst volume. One such method comprises the steps of (i) supplying an isobutane flow to a multizone alkylation reactor through an isobutane inlet; (ii) supplying an olefin-containing flow through a first plurality of olefin feed inlets located in each of a first plurality of alkylation zones in a first mechanically separated catalyst volume, and through a second plurality of olefin feed inlets located in a second plurality of alkylation zones in a second mechanically separated catalyst volume; and (iii) configuring an alkylate flow containing alkylates produced by the reaction of the olefin-containing flow with isobutane in each of the first plurality of alkylation zones for downward fluid flow of the alkylate flow through the first plurality of alkylation zones in the first mechanically separated catalyst volume. The process includes (iv) guiding the alkylate flow from the last alkylation zone in the first mechanically separated catalyst volume through the first alkylate product fluid passage to the first alkylation zone in the second mechanically separated catalyst volume; (v) guiding the alkylate flow from the first alkylation zone in the second mechanically separated catalyst volume through the second plurality of fluid passages configured for downward fluid flow of the alkylate flow through the second plurality of alkylation zones in the second mechanically separated catalyst volume; and (vi) guiding the alkylate flow from the last alkylation zone in the second mechanically separated catalyst volume through the second alkylate product fluid passage to a recirculation pump.In certain embodiments, the method may include the steps of: leading a first portion of the alkylate flow from a recirculation pump to further processing to produce a concentrated alkylate product containing a high-octane branched-chain paraffinic hydrocarbon; and recirculating a second portion of the alkylate flow to a first mechanically separated catalyst volume to maintain a desired ratio of isobutane to olefin. In certain embodiments, this ratio is in the range of about 300:1 to about 500:1.

[0009] Embodiments include a method for regenerating alkylation zones in a multizone alkylation reactor. The multizone alkylation reactor includes two mechanically separated catalyst volumes having first and second plurality of alkylation zones packed with spent alkylation catalyst, a first plurality of fluid passages configured for downward or upward fluid flow through the first plurality of alkylation zones in the first mechanically separated catalyst volume, and a second plurality of fluid passages configured for upward or downward fluid flow through the second plurality of alkylation zones in the second mechanically separated catalyst volume. One such method is to (i) guide the regenerated flow to a compressor to generate a compressed regenerated flow; (ii) feed the compressed regenerated flow to a heat exchanger arranged to directly alternate the spent regenerated flow from the outlet of a multizone alkylation reactor with the compressed regenerated flow to generate a high-temperature compressed regenerated flow and a cooled spent regenerated flow; (iii) guide the high-temperature compressed regenerated flow from the heat exchanger to a heater to generate a regenerated feed flow; (iv) feed the regenerated feed flow to the inlet of a multizone alkylation reactor; and (v The method includes the steps of: ) guiding a regenerated feed stream through a first plurality of fluid passages in a first plurality of alkylation zones and a first mechanically separated catalyst volume, and through a second plurality of fluid passages in a second plurality of alkylation zones and a second mechanically separated catalyst volume, thereby promoting interaction with the spent alkylation catalyst in the first and second plurality of alkylation zones under catalyst regeneration conditions, thereby regenerating the spent alkylation catalyst and producing a regenerated catalyst with significantly increased alkylation activity, and a spent regenerated stream exiting the outlet of a multizone alkylation reactor. In certain embodiments, the method may further include the steps of: feeding the spent regenerated stream from the outlet of the multizone alkylation reactor to a heat exchanger; guiding the spent regenerated stream from the heat exchanger to a gas-liquid separator, separating the spent material from the cooled spent regenerated stream, thereby producing a regenerated stream and a spent material stream containing soluble coke and insoluble coke. In certain embodiments, the regenerated stream contains a hydrogen-enriched gas. The hydrogen-enriched gas may contain approximately 70–90 weight percent (wt.%) of hydrogen. In certain embodiments, the heater is a heating furnace.

[0010] These embodiments and other features, aspects, and advantages of the present disclosure will be better understood in conjunction with the following description, claims, and accompanying drawings. However, it should be noted that the drawings illustrate only certain embodiments of the present disclosure and should not be considered to limit the scope of the present disclosure. [Brief explanation of the drawing]

[0011] [Figure 1] This is an explanatory diagram of a multizone alkylation system according to an embodiment of the present disclosure. [Figure 2] This is an explanatory diagram of a multizone alkylation system equipped with a deisobutane column according to an embodiment of the present disclosure. [Figure 3] This is a schematic diagram of an alkylation system according to embodiments of the present disclosure, which includes a multizone alkylation reactor coupled to several components (e.g., a heat exchanger, a cooler, a flash drum, a compressor, and a heater). [Figure 4] This is an explanatory diagram of a multizone alkylation system according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] This disclosure provides multizone alkylation systems and methods for the production of alkylates using these systems. Non-limiting embodiments of the methods and systems disclosed herein are described in more detail so that the features and advantages of the embodiments of the methods and systems disclosed herein, as well as other aspects that may become apparent, may be better understood. The following descriptions include many details so that the various embodiments may be fully understood. In other cases, well-known processes, apparatus, and systems may not be described in particular detail so as not to unnecessarily obscure the various embodiments. In addition, certain features or details may be omitted in the descriptions of the various embodiments so as not to obscure the various embodiments.

[0013] Alkylation reactors can be used to facilitate the processing of light olefins into high-quality, low-Reed vapor pressure (RVP) alkylates. Embodiments of alkylation systems include multizone alkylation reactors. These multizone alkylation reactors include multiple alkylation zones spaced apart in a vertically series configuration. The multizone alkylation reactor includes at least one partition plate that divides the multiple alkylation zones into at least a first mechanically separated catalyst volume and a second mechanically separated catalyst volume. In certain embodiments, the partition plate may be a vertical or horizontal partition plate. The multizone alkylation reactor also includes an isobutane inlet configured to supply an isobutane flow to the first mechanically separated catalyst volume and at least one olefin feed inlet configured to supply olefin-containing flows to the multiple alkylation zones. The isobutane feed stream and the olefin feed stream react under catalyst alkylation conditions to produce alkylate flows. The multizone alkylation reactor further includes a first alkylate product fluid passage that transports an alkylate flow from a first mechanically separated catalyst volume to a second mechanically separated catalyst volume. The alkylate flow contains the alkylate product along with unreacted isobutane and olefin. The alkylate flow may continue to flow in a first fluid flow direction until it reaches the last alkylation zone in the first mechanically separated catalyst volume. The alkylate flow may then be guided through the first alkylate product fluid passage from the last alkylation zone in the first mechanically separated catalyst volume to the first alkylation zone in the second mechanically separated catalyst volume. This alkylate flow may then be guided in a second fluid flow direction to the last alkylation zone in the second mechanically separated catalyst volume. In certain embodiments, both the first and second fluid flow directions are downward. In certain embodiments, the first fluid flow direction is downward and the second fluid flow direction is upward. In a particular embodiment, the first fluid flow direction is upward and the second fluid flow direction is downward. In a particular embodiment, both the first and second fluid flow directions are upward.In certain embodiments, the first and second fluid flow directions may include leftward flow, rightward flow, or a combination thereof in the corresponding mechanically separated catalyst volumes. In certain embodiments, two or more partition plates arranged vertically or horizontally may be used to divide multiple alkylation zones into at least two or more mechanically separated catalyst volumes.

[0014] Embodiments of the alkylation system include a multizone alkylation reactor. The multizone alkylation reactor may include a plurality of alkylation zones spaced apart in a vertical series configuration, as well as at least one vertical partition plate dividing the plurality of alkylation zones into at least two mechanically separated catalyst volumes. The multizone alkylation reactor may include a plurality of olefin feed inlets arranged to supply an olefin-containing flow to each of the plurality of alkylation zones in at least two mechanically separated catalyst volumes. The multizone alkylation reactor may also include an isobutane inlet for supplying isobutane to a first alkylation zone in a first mechanically separated catalyst volume. The multizone alkylation reactor may further include a first plurality of fluid passages configured for the fluid flow of alkylate flows through the plurality of alkylation zones in the first mechanically separated catalyst volume. In certain embodiments, the first alkylate product fluid passages of the multizone alkylation reactor may transport the alkylate flow from the last alkylation zone in the first mechanically separated catalyst volume to the first alkylation zone in a second mechanically separated catalyst volume. A multizone alkylation reactor may include a second set of fluid passages configured for the fluid flow of an alkylate stream through multiple alkylation zones within a second mechanically separated catalyst volume. The fluid flow may be downward or upward through the multiple alkylation zones. In addition, a second alkylate product fluid passage in the multizone alkylation reactor may transport the alkylate stream from the last alkylation zone within the second mechanically separated catalyst volume. In certain embodiments, the alkylate stream is then led to a recirculation pump. In embodiments having two or more vertical baffles, a third alkylate product fluid passage may transport the alkylate stream from the last alkylation zone within the second mechanically separated catalyst zone to a first alkylation zone within a third mechanically separated catalyst volume. Embodiments of a multizone alkylation reactor may include three catalyst volumes separated by two vertical baffles, four catalyst volumes separated by three vertical baffles, and so on.Furthermore, although sometimes described by reference to the downward fluid flow of the alkylation flow through the alkylation zone, multizone alkylation reactors can be designed to obtain upward fluid flow in all or some of the mechanically separated catalyst zones.

[0015] The olefin-containing stream may contain olefins (e.g., ethylene and propylene) and lighter components (e.g., hydrogen and methane). The alkylate stream may contain alkylates produced by the reaction of olefins with isobutane in the olefin-containing stream. The alkylates include mixtures of high-octane branched-chain paraffinic hydrocarbons. As referred to herein, high-octane hydrocarbons have an octane number of a predetermined threshold (e.g., 90) or higher. For example, high-octane hydrocarbons may include branched-chain isomers of octane, e.g., 2,2,4-trimethylpentane (iso-octane) and 2,2,3-trimethylpentane, and other trimethyl isomers of C8+ hydrocarbons. Each of the mechanically separated catalyst volumes may be configured as a hydraulically sealed reaction chamber. Each of the alkylation zones may contain a solid acid alkylation catalyst.

[0016] In certain embodiments, the recirculation pump may be configured to receive the alkylate flow from a second alkylate product fluid passage, direct a portion of the alkylate flow to further processing, and produce a concentrated alkylate product containing high-octane paraffinic hydrocarbons. In certain embodiments, the recirculation pump may be configured to recirculate the second portion of the alkylate flow to a first mechanically separated catalyst volume. Thus, the recirculation pump can maintain a desired ratio of isobutane to olefin in the multizone alkylation reactor. In certain embodiments, this ratio may range from about 300:1 to about 500:1, or about 350:1 to about 500:1, or about 400:1 to about 500:1, or about 300:1 to about 450:1, or about 300:1 to about 400:1. In certain embodiments, the flow rate of the recirculation pump may be reduced by at least 50 percent compared to the recirculation pump of a conventional alkylation reactor. In certain embodiments, the recirculation pump flow rate can be reduced by at least 30 or 40 percent compared to a conventional alkylation reactor recirculation pump. In certain embodiments, the recirculation pump flow rate can be reduced by at least 60 percent compared to a conventional alkylation reactor recirculation pump. In certain embodiments, the reduction in recirculation flow rate can correspond to a reduction in operating costs without impairing the product yield.

[0017] Figure 1 is an explanatory diagram of a multizone alkylation reactor according to an embodiment of the present disclosure. In a particular embodiment, the alkylation system 100 includes a multizone alkylation reactor 102. The multizone alkylation reactor 102 includes an outer shell 103 or enclosure structure. The multizone alkylation reactor 102 contains a plurality of alkylation zones 120 (for example, alkylation zones 120A, 120B, 120C, 120D, 120E, 120F, 120G, 120H, 120I, and 120J) defined within the outer shell 103. Alkylation zones 120A, 120B, 120C, 120D, and 120E are spaced apart in a vertical series configuration. Alkylation zones 120F, 120G, 120H, 120I, and 120J are spaced apart in a vertical series configuration. At least one vertical partition plate 104 separates a plurality of alkylation zones 120 into at least two mechanically separated catalyst volumes 105. In the illustrated embodiment, alkylation zones 120A, 120B, 120C, 120D, and 120E are defined within a first mechanically separated catalyst volume 105A, and alkylation zones 120F, 120G, 120H, 120I, and 120J are defined within a second mechanically separated catalyst volume 105B. The vertical partition plate 104 may be a solid plate extending vertically within the outer shell 103. In certain embodiments, this plate may be made of a metal or an inert material. For example, in a particular embodiment, the vertical partition plate extends in a plane defined from the upper inner surface to the lower inner surface of the outer shell 103, and from a first lateral inner surface to a second lateral inner surface on the opposite side of the outer shell 103. In certain embodiments, the vertical partition plate 104 may be welded to a suitable portion of the outer shell 103 of the multizone alkylation reactor 102 or be permanently bonded. In other embodiments, the vertical partition plate 104 may be removable and may be attached to the outer shell 103 by a partition plate support attachment. Although shown with a single vertical partition plate 104, two or more vertical partition plates 104 may be implemented in the multizone alkylation reactor 102 based on various operational factors (e.g., availability of physical space, ease of access to internal elements, and / or target product quality).Furthermore, although shown with 10 alkylation zones 120, the multizone alkylation reactor 102 can be designed to include any appropriate number of alkylation zones 120 (e.g., 2, 4, 6, 8, 12, 14, or more). The vertical partition plates 104 of this disclosure effectively increase the number of conventional alkylation stages by the number of vertical partition plates 104, thereby increasing the number of alkylation zones 120.

[0018] Multiple olefin supply inlets 114 (for example, olefin supply inlets 114A, 114B, 114C, 114D, 114E, 114F, 114G, 114H, 114I, and 114J) are arranged to supply the olefin-containing flow 110 through the outer shell 103 to each of the multiple alkylation zones 120, each located inside two mechanically separated catalyst volumes 105. For example, each of the olefin-containing streams 110A, 110B, 110C, 110D, 110E, 110F, 110G, 110H, 110I, and 110J may be received by the corresponding one of the alkylation zones 120A, 120B, 120C, 120D, 120E, 120F, 120G, 120H, 120I, and 120J through the corresponding olefin supply inlets 114A, 114B, 114C, 114D, 114E, 114F, 114G, 114H, 114I, and 114J. In a particular embodiment, the olefin-containing stream 110 contains olefins (e.g., ethylene and propylene) and lighter components (e.g., hydrogen and methane). In the illustrated embodiment, the isobutane stream 112 is provided through an inlet defined within the outer shell 103 and supplied to a first alkylation zone 120A within a first mechanically separated catalyst volume 105A. In certain embodiments, a portion of the isobutane is also premixed with an olefin feed stream 110 supplied to an olefin feed inlet 114. Each of the mechanically separated reaction volumes 105A and 105B may be configured as a hydraulically sealed reaction chamber. The two mechanically separated catalyst volumes 105, having alkylation zones 120 spaced apart in a vertically series configuration, can increase the total fluid flow length of the multizone alkylation reactor 102 available for the alkylation reaction relative to a given nominal length of the outer shell 103. Furthermore, the mechanically separated catalyst volume 105 can also increase the number of multiple olefin feed inlets 114 in the multizone alkylation reactor 102 compared to conventionally implemented reactors. In certain embodiments, the configuration of this multizone alkylation reactor 102 makes it possible to maintain the rate of the primary reaction between the olefin and the isoparaffin at least two orders of magnitude higher than the rate of the secondary reaction between the olefins.In certain embodiments, this configuration of the multi-zone alkylation reactor 102 allows for the maintenance of an optimal I / O ratio. Each alkylation zone 120 contains an alkylation catalyst suitable for producing alkylates, as described below. In certain embodiments, the reactor conditions may be similar to those of conventionally implemented alkylation reactors (e.g., K-SAAT reactors). In some embodiments, the alkylation reaction is carried out at a pressure in the range of 200–300 psi(g) and a temperature in the range of 43–82°C.

[0019] According to several embodiments, each of the alkylation zones 120 contains a solid acid alkylation catalyst, for example, a K-SAAT® catalyst (KBR, Houston, Tex.). Embodiments of solid acid catalyst alkylation are described, for example, in U.S. Patent No. 9,079,815 and U.S. Patent No. 1,017,9753, and U.S. Patent Application Publication No. 2020 / 0031733, which are incorporated herein by reference. The alkylation reaction between isobutane and an olefin (for example, one contained in the olefin-containing stream 110) can occur on a solid acid catalyst on a fixed bed within the alkylation zone 120. In fact, each alkylation zone 120 in this embodiment has its own fixed bed within it, as shown in the figures. The solid acid catalyst may be a zeolite catalyst as described in the reference patents and may contain a metal (for example, platinum, palladium, and / or nickel).

[0020] In this embodiment, the multizone alkylation reactor 102 includes a plurality of fluid passages 106 (e.g., channels, distribution plates) that guide the fluid flow of reactants and products as part of the alkylate flow through at least a portion of a plurality of alkylation zones 120. In a particular embodiment, the fluid passages 106 interconnect the alkylation zones 120 within each mechanically separated catalyst volume 105. For example, within a first mechanically separated catalyst volume 105A, the alkylate flow in alkylation zone 120A may flow sequentially through fluid passage 106A, alkylation zone 120B, fluid passage 106B, alkylation zone 120C, fluid passage 106C, alkylation zone 120D, fluid passage 106D, and alkylation zone 120E. The isobutane in the alkylate flow within each of these alkylation zones 120 may react with the olefin in each of the olefin-containing flows 110, as described above. The alkylate stream contains unreacted olefins and isobutane, in addition to the alkylate produced by the reaction of olefins in the olefin-containing stream with isobutane from the isobutane stream 112. The alkylate includes a mixture of high-octane branched-chain paraffinic hydrocarbons. As used herein, high octane refers to hydrocarbons or mixtures thereof whose octane number is above a given threshold. For example, the high-octane hydrocarbons in a particular embodiment have an octane number of 90 or higher. Achieving a valuable high-octane fuel involves a primary reaction between isobutane and butene to produce isooctane. As described herein, the alkylation system 100 produces an alkylate with a low RVP, thereby increasing the alkylate yield. In the multizone alkylation reactor 102, isobutane and butene are alkylated to produce isooctane and n-butane. A subsequent fractional distillation process may decompose the alkylate stream through two reactions. In the first reaction, isooctane can be broken down into isopentane and propylene. In the second reaction, isobutane and propylene can be broken down into isoheptane.

[0021] In the illustrated embodiment, the first alkylate product fluid passage 117 is arranged to transport the alkylate flow from the last alkylation zone 120E (or the bottommost alkylation zone) in the first mechanically separated catalyst volume 105A to the first alkylation zone 120F (or the topmost alkylation zone) in the second mechanically separated catalyst volume 105B. Multiple fluid passages 106 guide the fluid flow of the alkylate flow through the alkylation zone 120 in the second mechanically separated catalyst volume 105B. For example, the alkylate flow in alkylation zone 120F may flow sequentially through fluid passage 106F, alkylation zone 120G, fluid passage 106G, alkylation zone 120H, fluid passage 106H, alkylation zone 120I, fluid passage 106I, and alkylation zone 120J. The isobutane in the alkylate stream within each of these alkylation zones 120 can react with the olefin in each of the olefin-containing streams 110, as described above.

[0022] In certain embodiments, the second alkylate product fluid passage 118 can transport the alkylate flow from the last alkylation zone 120J (or the bottom alkylation zone) in the second mechanically separated catalyst volume 105B to the recirculation pump 108 of the alkylation system 100. The recirculation pump 108 can be any suitable fluid transfer device for receiving the alkylate flow from the second alkylate product fluid passage 118. Thus, the alkylation system 100 can generate a first portion 119 of the alkylate flow as a product or intermediate product and recirculate the second portion 116 of the alkylate flow back to the first mechanically separated catalyst volume 105A to maintain a desired or target ratio of isobutane to olefin therein. In certain embodiments, the target ratio of isobutane to olefin is in the range of about 300:1 to about 500:1. In certain embodiments, the target ratio of isobutane to olefin is about 400:1. As used herein, a threshold or high ratio of isobutane to olefin refers to a ratio of approximately 300:1 or higher.

[0023] In certain embodiments, the amount of alkylate recycled to the multi-zone alkylation reactor 102 is calculated to minimize macro-mixing and micro-mixing characteristics. The alkylation system 100 of the present disclosure has one or more vertical partition plates 104, which achieves a significant reduction of more than 50% in the amount of alkylate stream recycled back to the multi-zone alkylation reactor 102 compared to a system without vertical partition plates.

[0024] Furthermore, by adding the vertical partition plates 104, the cross-sectional area of each alkylation zone 120 can be reduced compared to an alkylation reactor without partition plates. In this embodiment, the length (e.g., reaction length, zone height) of the alkylation zone 120 can remain the same. Each mechanically separated catalyst volume 105 can have a balanced distribution of the respective olefin-containing stream 110 and isobutane stream 112 across the alkylation zone 120. In the illustration, it includes a downward flow of fluid through each of the mechanically separated catalyst volumes 105, but other embodiments of the present disclosure can alternatively provide an upward flow of fluid through one, two or more, or all of the mechanically separated catalyst volumes 105. As used herein, the downward flow direction can generally refer to a flow direction corresponding to or parallel to gravity, and the upward flow direction can generally refer to a flow direction opposite to gravity. Additionally, certain embodiments of the present disclosure can include a design of the multi-zone alkylation reactor 102 in which the outer shell 103 extends generally horizontally rather than generally vertically as shown in FIG. 1. In such embodiments, the vertical partition plates 104 can be adjusted to be horizontal partition plates that promote a leftward flow, a rightward flow, or a combination thereof in the corresponding mechanically separated catalyst volume 105.

[0025] In certain embodiments, the solid acid alkylation catalyst in the alkylation zone 120 can contain a zeolite material that supports a non-noble metal. An example of a suitable catalyst is KBR's ExSact™ catalyst. This is a zeolite-based catalyst that is selective for high-octane TMP and excludes oil soluble in acid. Suitable catalysts can have improved mass transfer to prevent pore plugging, can promote alkylation over polymerization reactions, can be highly selective for 2,3,3- and 2,3,4-trimethylpentane, and can have minimal isomerization of trimethylpentane to dimethylhexane. In some embodiments, the alkylation reaction within the multi-zone alkylation reactor 102 is carried out at low temperature (e.g., 40-80°C), is slightly exothermic, and provides a radial temperature profile or distribution within about 2.8 or 3°C. In this embodiment, the mechanically separated catalyst volume 105 can reduce the macro-mixing characteristics and micro-mixing characteristics within the multi-zone alkylation reactor 102. Reducing the macro-mixing and micro-mixing characteristics includes minimizing the mixing volume within the multi-zone alkylation reactor 102, reducing the backup mixing supplied to the multi-zone alkylation reactor 102, and reducing the portion 116 of the alkylate stream recycled back to the multi-zone alkylation reactor 102 by the recycle pump 108.

[0026] The ratio of isobutane to olefin can generally control the alkylate concentration within the multi-zone alkylation reactor 102. At a target or high ratio of isobutane to olefin of 300:1 or greater, the multi-zone alkylation reactor 102 can produce high-octane alkylate. Additionally, a high ratio of isobutane to olefin can improve the catalyst life. In these embodiments, the flow rate of the recycle pump 108 of the alkylation reactor can be reduced by at least 50 percent compared to the recycle pump in a conventional alkylation system. By reducing the flow rate of the recycle pump 108, the amount of alkylate stream that can be further processed can be increased.

[0027] Embodiments also include methods for increasing alkylate production and reducing recirculation flow to a multizone alkylation reactor. One such method for reducing recirculation to a multizone alkylation reactor may involve directing an isobutane flow to multiple alkylation zones within the multizone alkylation reactor. The multizone alkylation reactor may include at least one vertical partition plate that separates the multiple alkylation zones into at least two mechanically separated catalyst volumes. An olefin-containing flow may be directed to each alkylation zone in two or more mechanically separated catalyst volumes via multiple olefin feed inlets. Isobutane may be supplied through an isobutane inlet to a first alkylation zone in a first mechanically separated catalyst volume. In one embodiment, isobutane may react with an olefin in the first alkylation zone in the first mechanically separated catalyst volume to produce an alkylate flow. Therefore, as the isobutane and each olefin-containing stream react within their respective alkylation zones, the amount of alkylate in the alkylate stream can increase as the reaction continues to the last alkylation zone in the first mechanically separated catalyst volume. The alkylate stream can then be guided through the first alkylate product fluid passage from the last alkylation zone in the first mechanically separated catalyst volume to the first alkylation zone in the second mechanically separated catalyst volume. The alkylate stream can then be guided from the first alkylation zone in the second mechanically separated catalyst volume to continue the alkylation reaction between the isobutane and each olefin-containing stream, which is provided to the alkylation zone in the second mechanically separated catalyst volume. This alkylate stream can then be guided to the last alkylation zone in the second mechanically separated catalyst volume, increasing the amount of alkylate therein. The alkylate stream can then be guided from the last alkylation zone in the second mechanically separated catalyst volume to a recirculation pump. The alkylate stream exiting the recirculation pump can be separated into a first portion and a second portion. The first portion of the alkylate stream can be led from a recirculation pump and further processed to produce a concentrated alkylate product containing high-octane branched-chain paraffinic hydrocarbons.The second portion of the alkylate flow is led from the recirculation pump to a first alkylation zone in a first mechanically separated catalyst volume, where a desired ratio of isobutane to olefin can be maintained. In certain embodiments, this ratio ranges from about 300:1 to about 500:1.

[0028] Figure 2 is an explanatory diagram of a multizone alkylation system 200 equipped with a deisobutane column according to an embodiment of the present disclosure. In a particular embodiment, the alkylate production system 200 includes a multizone alkylation reactor 102. The multizone alkylation reactor 102 in Figure 2 may generally correspond to the multizone alkylation reactor 102 in Figure 1, and the corresponding elements may be described with reference to their operation within the alkylate production system 200. For example, the multizone alkylation reactor 102 of this embodiment includes a plurality of alkylation zones 120 (e.g., alkylation zones 120A, 120B, 120C, 120D, 120E, 120F, 120G, 120H, 120I, and 120J), which are defined within an outer shell 103 and may be spaced apart in a vertical series configuration. At least one vertical partition plate 104 separates the plurality of alkylation zones 120 into at least two mechanically separated catalyst volumes 105A and 105B. Multiple olefin supply inlets 114 (e.g., olefin supply inlets 114A, 114B, 114C, 114D, 114E, 114F, 114G, 114H, 114I, and 114J) may be arranged to supply an olefin-containing flow 110 to each of the plurality of alkylation zones 120 within the two mechanically separated catalyst volumes 105A and 105B. An isobutane flow 112 is supplied to the first alkylation zone 120A within the first mechanically separated catalyst volume 105A. In this embodiment, the multizone alkylation reactor 102 includes multiple fluid passages 106 that guide the fluid flow of the alkylate flow through at least a portion of the plurality of alkylation zones 120. For example, the alkylate flow in alkylation zone 120A may flow sequentially through fluid passage 106A, alkylation zone 120B, fluid passage 106B, alkylation zone 120C, fluid passage 106C, alkylation zone 120D, fluid passage 106D, and alkylation zone 120E. The first plurality of fluid passages 106A, 106B, 106C, and 106D may be configured to provide downward fluid flow of the alkylate flow from alkylation zone 120A through alkylation zones 120B, 120C, 120D, and 120E within the first mechanically separated catalyst volume 105A.

[0029] The first alkylate product fluid passage 117 can transport the alkylate flow from the last alkylation zone 120E in the first mechanically separated catalyst volume 105A to the first alkylation zone 120F in the second mechanically separated catalyst volume 105B. The second set of fluid passages 106F, 106G, and 106H, and 106I may be configured to provide downward fluid flow of the alkylate flow from alkylation zone 120F through alkylation zones 120G, 120H, 120I, and 120J in the second mechanically separated catalyst volume 105B. For example, the alkylate flow in alkylation zone 120F may flow sequentially through fluid passage 106F, alkylation zone 120G, fluid passage 106G, alkylation zone 120H, fluid passage 106H, alkylation zone 120I, fluid passage 106I, and alkylation zone 120J. A second alkylate product fluid passage 118 can transport the alkylate flow from the last alkylation zone 120J in the second mechanically separated catalyst volume 105B to the recirculation pump 108. The recirculation pump 108 of the alkylation system 200 is configured to receive the alkylate flow from the second alkylate product fluid passage 118 and recirculate the first portion 119 of the alkylate flow from the recirculation pump 108 to the deisobutane column 216. The alkylation production system 200 can also recirculate the second portion 116 of the alkylate flow directly back to the first mechanically separated catalyst volume 105A to maintain a desired or target ratio of isobutane to olefin. In certain embodiments, the target ratio of isobutane to olefin is in the range of about 300:1 to about 500:1. In certain embodiments, the target ratio of isobutane to olefin is about 400:1. As used herein, a threshold or high ratio of isobutane to olefin refers to a ratio of approximately 300:1 or higher.

[0030] The deisobutane column 216 of the alkylate production system 200 is configured to receive a first portion 119 of the alkylate flow from the recirculation pump 108 and separate the first portion 119 of the alkylate flow into (i) a recycled isobutane flow 222 supplied to a first mechanically separated catalyst volume 105A, (ii) a normal butane or n-butane flow 218, and (iii) a product flow 220 containing a mixture of high-octane branched-chain paraffinic hydrocarbons. As used herein, high-octane components refer to hydrocarbons or mixtures thereof whose octane number is above a predetermined threshold (e.g., octane number 90 or higher). The recycled isobutane flow 222 may be rich in isobutane and may be taken out as a by-flow and recycled to the multizone alkylation reactor 102 for further alkylate production. As is currently recognized, the alkylation manufacturing system 200, by having one or more vertical partition plates 104, achieves a significant reduction of more than 50% in the amount of alkylate recycled back into the multi-zone alkylation reactor 102 compared to systems without vertical partition plates.

[0031] Another embodiment of a method for increasing alkylate production and reducing recirculation flow to a multizone alkylation reactor involves including a deisobutane column in the alkylation system. An olefin-containing flow can be directed through a plurality of olefin feed inlets to each alkylation zone in two or more mechanically separated catalyst volumes of a multizone alkylation reactor. Isobutane can be supplied through an isobutane inlet. The isobutane can start from a first alkylation zone in a first mechanically separated catalyst volume and interact with the olefin-containing flow to generate an alkylate flow. Thus, the alkylate flow can continue to contain alkylates produced by the reaction of isobutane with olefins from each of the olefin-containing flows in each alkylation zone. The alkylate flow can continue to flow in a first fluid flow direction until it reaches the last alkylation zone in the first mechanically separated catalyst volume. The alkylate flow can then be directed through a first alkylate product fluid passage from the last alkylation zone in the first mechanically separated catalyst volume to a first alkylation zone in a second mechanically separated catalyst volume. The alkylate flow may contain alkylates produced by the reaction of isobutane with olefins from each of the olefin-containing flows within each alkylation zone. This alkylate flow may be directed in a second fluid flow direction to the last alkylation zone in a second mechanically separated catalyst volume. In certain embodiments, both the first and second fluid flow directions are downward. In certain embodiments, the first fluid flow direction is downward and the second fluid flow direction is upward. In certain embodiments, both the first and second fluid flow directions are upward. The alkylate flow may then be directed from the last alkylation zone in the second mechanically separated catalyst volume to a recirculation pump. The recirculation pump may be configured to maintain a desired ratio of isobutane to olefin by circulating a first portion of the alkylate flow from the recirculation pump to the deisobutane column and a second portion of the alkylate flow to a first mechanically separated catalyst volume.In certain embodiments, this ratio is in the range of approximately 300:1 to approximately 500:1. The first portion of the alkylate flow is led from a recirculation pump to a deisobutane column of a certain embodiment, where the first portion of the alkylate flow can be separated into (i) a recycled isobutane flow supplied to a first mechanically separated catalyst volume, (ii) a normal butane flow, and (iii) a product flow containing a mixture of high-octane branched-chain paraffinic hydrocarbons. The recycled isobutane flow is then led to a first alkylation zone in the first mechanically separated catalyst volume, where it can be alkylated with the isobutane inlet flow and each olefin-containing flow.

[0032] Although Figures 1 and 2 show only one multizone alkylation reactor, embodiments of the alkylation system may include two, three, or more such reactors. For example, two or more multizone alkylation reactors may be connected in parallel to one another. In certain embodiments, a single inlet flow may be split and supplied to each multizone alkylation reactor before or after confluence with recycled isobutane. Furthermore, in certain embodiments, an outlet flow may be received from each multizone alkylation reactor and confluenced before or after splitting the isobutane-enriched flow from the outlet flow. In certain embodiments, each reactor may operate with a cycle length of 24 hours, and the ratio of feed isobutane to olefin may range from about 5 mol / mol to about 10 mol / mol, which may be measured before the feed flow is supplied to two or more multizone alkylation reactors. The ratio of bed isobutane to olefin may range from 300 mol / mol to 500 mol / mol, as previously mentioned. Alkylation reaction conditions can include temperatures of approximately 40–80°C and pressures of approximately 232–363 psi(g). This temperature range may be more favorable and desirable for alkylation than for polymerization.

[0033] Embodiments may also include methods for regenerating the alkylation zones of a multizone alkylation reactor. In one such embodiment, the multizone alkylation reactor includes two mechanically separated catalyst volumes having a first and a second plurality of alkylation zones which can be filled with spent alkylation catalyst. The multizone alkylation reactor may include a first plurality of fluid passages configured for fluid flow within the first mechanically separated catalyst volume and a second plurality of fluid passages configured for fluid flow through the second mechanically separated catalyst volume. As previously stated, the fluid flow through the first plurality of alkylation zones of the first mechanically separated catalyst volume may be provided in an upward or downward direction. Similarly, the fluid flow through the second plurality of alkylation zones of the second mechanically separated catalyst volume may be provided in an upward or downward direction. One such method may include (i) leading the regenerated flow to a compressor to produce a compressed regenerated flow. In certain embodiments, the regenerated flow contains a hydrogen-enriched gas. The hydrogen-enriched gas may contain approximately 60 wt.% to 90 wt.%, or approximately 70 wt.% to 90 wt.%, or approximately 75 wt.% to 85 wt.%, or approximately 70 wt.%, or approximately 80 wt.% of hydrogen. In certain embodiments, the regenerated flow may contain other components, such as helium, or ozone, or oxygen. The method may also include (ii) supplying the compressed regenerated flow to a heat exchanger arranged to directly alternate the spent regenerated flow from the outlet of a multizone alkylation reactor with the compressed regenerated flow, thereby producing a high-temperature compressed regenerated flow and a cooled spent regenerated flow. The method may further include (iii) leading the high-temperature compressed regenerated flow from the heat exchanger to a heater, thereby producing a regenerated feed flow. In certain embodiments, the heater is a heating furnace. In addition, the method may also include (iv) supplying a regenerative feed stream to the inlet of a multizone alkylation reactor, and (v) guiding the regenerative feed stream through a first plurality of alkylation zones in a first mechanically separated catalyst volume and through a second plurality of alkylation zones in a second mechanically separated catalyst volume.This flow can regenerate the spent alkylation catalyst by facilitating interaction with the spent alkylation catalyst in the first and second alkylation zones under catalyst regeneration conditions. The flow can also generate a spent regenerated stream exiting the outlet of the multizone alkylation reactor with a regenerated catalyst having significantly increased alkylation activity. The term "significantly" means that the activity of the spent catalyst composition increases by at least about 50%, or at least about 60%, or at least about 70 wt.%, or at least about 80 wt.%, or at least about 90 wt.%, at least about 95 wt.%, at least about 97 wt.%, or at least about 99 wt.%, or more. In certain embodiments, the regenerated catalyst may have activity similar to that of a new catalyst. The method may also include (vi) supplying the spent regenerated stream from the outlet of the multizone alkylation reactor to a heat exchanger, and (vii) guiding the spent regenerated stream from the heat exchanger to a gas-liquid separator. A gas-liquid separator can separate the spent material from the cooled spent regenerated flow to produce a regenerated flow and a spent material flow. In certain embodiments, catalyst regeneration conditions may include a temperature of up to 275°C and a pressure of about 290 psi(g).

[0034] Figure 3 is a schematic diagram of an embodiment 300 of an alkylation system including a multizone alkylation 102 reactor coupled to several components. According to embodiments of the present disclosure, the components may include one or more of a heat exchanger, cooler, flash drum, compressor, and / or heater that constitute a regeneration system. In the illustrated embodiment, the alkylation system 300 includes a compressor 322, a heat exchanger 324, a cooler 326, a gas-liquid separator 328, and a heater 330. In a particular embodiment, the heater is a heating furnace. These components and / or other suitable components may be used to regenerate one or more alkylation zones 120 of the multizone alkylation reactor 102. In this embodiment, the compressor 322 receives the regeneration flow 312. The compressor 322 is a suitable compressor configured to compress the regeneration flow 312 to produce a compressed regeneration flow 310. In a particular embodiment, the regeneration flow 312 contains about 60 wt.% to about 90 wt.% of hydrogen. In certain embodiments, the regeneration pressure of the compressed regenerated flow 310 may be based on the purity of the regenerated gas. In some embodiments, the regeneration pressure may be selected to satisfy a minimum or target H2 partial pressure threshold (e.g., about 150–180 psi(g)) at the reactor outlet to enable effective regeneration operations. The heat exchanger 324 may receive the compressed regenerated flow 310 from the compressor 322. In this embodiment, the heat exchanger 324 may be configured to direct the compressed regenerated flow 310 with the spent regenerated flow 336 from the outlet of the multizone alkylation reactor 102, thereby producing a high-temperature compressed regenerated flow 316 and a cooled spent regenerated flow 304. In other embodiments, the heat exchanger 324 may implement counterflow or parallel flow between the compressed regenerated flow 310 and the spent regenerated flow 336. The heater 330 receives a high-temperature compressed regenerated flow 316 from the heat exchanger 324 and can heat the high-temperature compressed regenerated flow 316 to produce a regenerated feed flow 318. In certain embodiments, the regenerated feed flow 318 is heated to 275°C. In certain embodiments, the heater is a heating furnace. In the illustrated embodiment, the first inlet 332 of the multizone alkylation reactor 102 receives the regenerated feed flow 318.The multizone alkylation reactor 102 may include two or more mechanically separated catalyst volumes 105 separated by one or more vertical partition plates 104. The mechanically separated catalyst volume 105 may include a first plurality of alkylation zones (120A, 120B, 120C, 120D, and 120E) and a second plurality of alkylation zones (120F, 120G, 120H, 120I, and 120J) filled with spent alkylation catalyst. The first plurality of fluid passages 106A, 106B, 106C, and 106D are configured to cause a downward fluid flow of regenerated feed flow 318 within the first mechanically separated catalyst volume 105A, from alkylation zone 120A through alkylation zones 120B, 120C, 120D, and 120E. In certain embodiments, the regeneration feed stream 318 interacts with the spent alkylation catalyst in the first plurality of alkylation zones under catalyst regeneration conditions. This interaction can regenerate the spent alkylation catalyst, potentially producing a regenerated catalyst with significantly increased alkylation activity. During regeneration in the multi-zone alkylation reactor 102, soft coke deposited on the catalyst can be removed by the regeneration feed stream 318.

[0035] The first alkylate product fluid passage 117 is configured to receive a regenerated feed flow 318 from the last alkylation zone 120E in the first mechanically separated catalyst volume 105A and to direct the regenerated feed flow 318 to the second inlet 334 of the multizone alkylation reactor 102. The first alkylation zone 120F in the second mechanically separated catalyst volume 105B may receive a regenerated feed flow 318 from the second inlet 334. The second set of fluid passages 106E, 106F, 106G, and 106H are configured to cause a downward fluid flow of the regenerated feed flow 318 from alkylation zone 120F through alkylation zones 120G, 120H, 120I, and 120J in the second mechanically separated catalyst volume 105B. Therefore, under catalyst regeneration conditions, the regenerated feed stream 318 flows through a second plurality of alkylation zones 120F, 120G, 120H, 120I, and 120J and a second plurality of fluid passages 106F, 106G, 106H, and 106I, facilitating interaction with the spent alkylation catalyst therein to regenerate the spent alkylation catalyst and produce a regenerated catalyst with significantly increased alkylation activity and a spent regenerated stream 336. In certain embodiments, catalyst regeneration conditions in the multizone alkylation reactor 102 include a maximum temperature of 275°C and a pressure of about 290 psi(g). In some embodiments, catalyst regeneration uses reformer-grade hydrogen. The spent regenerated stream 336 can exit from the outlet 102 of the multizone alkylation reactor. A heat exchanger 324 may receive the spent regenerated stream 336 from the outlet 102 of the multizone alkylation reactor and produce a cooled spent regenerated stream 304. In some embodiments, the cooler 326 can receive the cooled spent regenerated flow 304 from the heat exchanger 324 and further cool the cooled spent regenerated flow 304 to produce a second cooled spent regenerated flow 306. The gas-liquid separator 328 can receive the cooled spent regenerated flow 304 from the heat exchanger 324 and / or the second cooled spent regenerated flow 306 from the cooler 326. In certain embodiments, the gas-liquid separator 328 can be a flash drum. In certain embodiments, the gas-liquid separator 328 can also receive a liquid hydrocarbon flow 308.The gas-liquid separator 328 can separate spent material (e.g., C1-C4 hydrocarbons) from the cooled spent-regenerated stream 304 and / or a second cooled spent-regenerated stream 306 to produce a substantially pure hydrogen stream 314 from which the regenerated stream 312 can be extracted or separated. The gas-liquid separator 328 can also produce a spent material stream 340 containing material to be removed (e.g., C1-C4 hydrocarbons). Thus, the regenerated stream 312 can be decontaminated and regenerated for further use within the alkylation system 300.

[0036] Figure 4 is an explanatory diagram of an alkylation system 400 containing a multizone alkylation reactor 402. In the aforementioned figures, in certain other embodiments, it is described as having downward flow through each of the mechanically separated catalyst volumes 105, but the multizone alkylation reactor 402 provides downward fluid flow in the first mechanically separated catalyst volume 105A and upward fluid flow in the second mechanically separated catalyst volume 105B. Certain other components of the multizone alkylation reactor 402 may generally correspond to the multizone alkylation reactor 102 in Figure 1, and the corresponding elements may be described with reference to their operation in the alkylation system 400. For example, the multizone alkylation reactor 402 of this embodiment contains a plurality of alkylation zones 120 (e.g., alkylation zones 120A, 120B, 120C, 120D, 120E, 120F, 120G, 120H, 120I, and 120J), which are defined within the outer shell 103 and can be spaced apart in a vertical series configuration. At least one vertical partition plate 104 separates the plurality of alkylation zones 120 into at least a first mechanically separated catalyst volume 105A and a second mechanically separated catalyst volume 105B. Multiple olefin supply inlets 114 (for example, olefin supply inlets 114A, 114B, 114C, 114D, 114E, 114F, 114G, 114H, 114I, and 114J) may be arranged to supply olefin-containing streams 110 to each of multiple alkylation zones 120 within two mechanically separated catalyst volumes 105A and 105B. An isobutane stream 112 is supplied to a first alkylation zone 120A within the first mechanically separated catalyst volume 105A. In this embodiment, the multizone alkylation reactor 102 includes multiple fluid passages 106 that guide the fluid flow of the alkylate stream through at least a portion of the multiple alkylation zones 120. For example, the alkylate flow in alkylation zone 120A may flow sequentially through fluid passage 106A, alkylation zone 120B, fluid passage 106B, alkylation zone 120C, fluid passage 106C, alkylation zone 120D, fluid passage 106D, and alkylation zone 120E.The first set of fluid passages 106A, 106B, 106C, and 106D may be configured to provide a downward fluid flow of alkylate flow through alkylation zones 120A to alkylation zones 120B, 120C, 120D, and 120E within the first mechanically separated catalyst volume 105A.

[0037] The first alkylate product fluid passage 117 can transport the alkylate flow from the last alkylation zone 120E in the first mechanically separated catalyst volume 105A to the first alkylation zone 120F in the second mechanically separated catalyst volume 105B. In this embodiment, the first alkylation zone 120F is the lowest alkylation zone in the second mechanically separated catalyst volume 105B. Thus, the second set of fluid passages 106F, 106G, and 106H, and 106I can be configured to provide upward fluid flow of the alkylate flow from alkylation zone 120F through alkylation zones 120G, 120H, 120I, and 120J in the second mechanically separated catalyst volume 105B. For example, the alkylate flow in alkylation zone 120F may flow sequentially through fluid passage 106F, alkylation zone 120G, fluid passage 106G, alkylation zone 120H, fluid passage 106H, alkylation zone 120I, fluid passage 106I, and alkylation zone 120J. A second alkylate product fluid passage 118 may transport the alkylate flow from the last alkylation zone 120J in the second mechanically separated catalyst volume 105B to the recirculation pump 108.

[0038] Therefore, the alkylation system 400 provides downward fluid flow in the first mechanically separated catalyst volume 105A and upward fluid flow in the second mechanically separated catalyst volume 105B. In certain embodiments, this mixed or combined flow direction arrangement of the alkylation system 400 allows for shortened or optimized lengths of fluid passages or piping (e.g., including the first alkylate product fluid passage 117 and / or the second alkylate product fluid passage 118) compared to embodiments having downward fluid flow in each mechanically separated catalyst volume 105 or embodiments having upward fluid flow in each mechanically separated catalyst volume 105.

[0039] Where ranges are disclosed herein, a range from any lower limit may, in combination with any upper limit, describe ranges not expressly stated; a range from any lower limit may, in combination with any other lower limit, describe ranges not expressly stated; and similarly, a range from any upper limit may, in combination with any other upper limit, describe ranges not expressly stated. In addition, references to values ​​indicated in a range include all values ​​within that range, even if not expressly stated. Thus, every point or individual value may, in combination with any other point or individual value, or any other lower or upper limit, function as its own lower or upper limit, describing ranges not expressly stated.

[0040] The drawings and specification disclose several embodiments of systems involving multizone alkylation reactors. Certain terminology is used, but these terms are for illustrative purposes only and not intended to be limiting. Embodiments of systems and methods are described in considerable detail, with specific reference to the exemplary embodiments. However, it is clear that various modifications and changes can be made within the spirit and scope of the embodiments of systems and methods described in the specification, and such modifications and changes should be considered equivalents of and part of this disclosure.

Claims

1. Alkylation system, The multizone alkylation reactor is included, Multiple alkylation zones spaced apart in a vertically oriented series configuration, The plurality of alkylation zones are divided into at least one vertical partition plate and at least one mechanically separated catalyst volume and a second mechanically separated catalyst volume, An isobutane inlet is arranged to supply an isobutane flow to the first mechanically separated catalyst volume, An olefin supply inlet is provided to supply an olefin-containing flow to the plurality of alkylation zones, wherein the olefin-containing flow reacts with the isobutane flow to generate an alkylate flow. A first alkylate product fluid passage that transports the alkylate flow from the first mechanically separated catalyst volume to the second mechanically separated catalyst volume, Alkylation systems including

2. The aforementioned multizone alkylation reactor is A first plurality of fluid passages interconnecting each alkylation zone within the first mechanically separated catalyst volume, A second set of fluid passages interconnecting each of the alkylation zones within the second mechanically separated catalyst volume, The alkylation system according to claim 1, comprising:

3. The alkylation system according to claim 1, wherein the plurality of alkylation zones are configured to guide the alkylate flow in a downward flow direction in each of the first mechanically separated catalyst volume and the second mechanically separated catalyst volume.

4. The alkylation system according to claim 1, wherein the plurality of alkylation zones are configured to guide the alkylate flow in an upward flow direction in at least one of the first mechanically separated catalyst volume and the second mechanically separated catalyst volume.

5. The alkylation system according to claim 1, wherein each of the first mechanically separated catalyst volume and the second mechanically separated catalyst volume is a hydraulically sealed reaction chamber.

6. The alkylation system according to claim 1, wherein the at least one olefin supply inlet includes a plurality of olefin supply inlets configured to supply the olefin-containing flow to each of the plurality of alkylation zones.

7. The alkylation system according to claim 1, wherein the first alkylate product fluid passage is configured to transport the alkylate flow from the last alkylation zone in the first mechanically separated catalyst volume to the first alkylation zone in the second mechanically separated catalyst volume, and the multizone alkylation reactor includes a second alkylate product fluid passage for transporting the alkylate flow from the last alkylation zone in the second mechanically separated catalyst volume.

8. The alkylation system according to claim 7, wherein the second alkylate product fluid passage is configured to transport the alkylate flow to a recirculation pump.

9. The recirculation pump includes the aforementioned recirculation pump, and the recirculation pump is Receiving the alkylate flow from the second alkylate product fluid passage, The first portion of the alkylate flow is subjected to further processing to produce a concentrated alkylate product containing high-octane branched-chain paraffinic hydrocarbons, The second portion of the alkylate flow is recirculated to the first mechanically separated catalyst volume, thereby maintaining the ratio of isobutane to olefin in the multizone alkylation reactor in the range of approximately 300:1 to approximately 500:

1. The alkylation system according to claim 8, configured to perform the following:

10. The recirculation pump includes the aforementioned recirculation pump, and the recirculation pump is Receiving the alkylate flow from the second alkylate product fluid passage, The first portion of the alkylate flow is directed to the deisobutane column, The second portion of the alkylate flow is recirculated to the first mechanically separated catalyst volume, thereby maintaining the ratio of isobutane to olefin in the multizone alkylation reactor in the range of approximately 300:1 to approximately 500:

1. The alkylation system according to claim 8, configured to perform the following:

11. The deisobutane column comprises the first portion of the alkylate flow from the recirculation pump, A recycled isobutane stream supplied to the first mechanically separated catalyst volume, n-butane flow and, Product stream containing high-octane branched-chain paraffinic hydrocarbons, It is configured to be separated into, The alkylation system according to claim 10.

12. The alkylation system according to claim 1, wherein the multizone alkylation reactor includes at least two vertical partition plates defining three mechanically separated catalyst volumes.

13. The alkylation system according to claim 12, wherein the multizone alkylation reactor includes a second alkylate product fluid passage configured to transport the alkylate flow from the second mechanically separated catalyst volume to the third mechanically separated catalyst volume.

14. A method for producing an alkylate, wherein the method is The method involves supplying an isobutane stream to a multizone alkylation reactor, wherein the multizone alkylation reactor has at least one vertical partition plate, the vertical partition plate defining a first mechanically separated catalyst volume containing a first plurality of alkylation zones and a second mechanically separated catalyst volume containing a second plurality of alkylation zones. An alkylate flow is generated by supplying an olefin-containing flow to the first plurality of alkylation zones and the second plurality of alkylation zones through at least one olefin supply inlet, The alkylate flow is guided from the first plurality of alkylation zones through the first alkylate product fluid passage to the second plurality of alkylation zones, A method that includes this.

15. The alkylate flow is guided from the second plurality of alkylation zones through the second alkylate product fluid passage to the recirculation pump, A portion of the alkylate flow is recirculated from the recirculation pump to the first mechanically separated catalyst volume, thereby maintaining the ratio of isobutane to olefin in the multizone alkylation reactor in the range of approximately 300:1 to approximately 500:

1. The method according to claim 14, further comprising:

16. The alkylate flow is guided in a downward flow direction through the first plurality of alkylation zones, The method according to claim 14, further comprising directing the alkylate flow through the second plurality of alkylation zones in the downward flow direction.

17. The alkylate flow is guided in a downward flow direction through the first plurality of alkylation zones, The alkylate flow is guided in an upward flow direction through the second plurality of alkylation zones, The method according to claim 14, further comprising:

18. A method for regenerating the alkylation zone of a multizone alkylation reactor, wherein the method is The method involves supplying a regenerative feed stream to the inlet of a multizone alkylation reactor, wherein the multizone alkylation reactor has a vertical partition plate, and the vertical partition plate is A first mechanically separated catalyst volume containing a first plurality of alkylation zones, A second mechanically separated catalyst volume containing a second plurality of alkylation zones, and a supply that defines and provides, The regenerated supply flow is introduced through the first mechanically separated catalyst volume and the second mechanically separated catalyst volume, thereby generating a regenerated catalyst with significantly increased alkylation activity and a spent regenerated flow, and the spent alkylation catalyst is regenerated within it. The used regenerated flow is guided outside from the outlet of the multizone alkylation reactor, A method that includes this.

19. A regenerated flow containing at least 60 weight percent hydrogen is introduced into a compressor to generate a compressed regenerated flow, The compressed regenerated flow is supplied to a heat exchanger arranged to directly alternate between the spent regenerated flow from the multizone alkylation reactor and the compressed regenerated flow, thereby generating a high-temperature compressed regenerated flow and a cooled spent regenerated flow. The high-temperature compressed regenerated flow is guided from the heat exchanger to the heater to generate the regenerated supply flow, The method according to claim 18, comprising generating the regenerated supply flow by means of the method.

20. The used regenerated flow from the multizone alkylation reactor is supplied to the heat exchanger, The cooled spent regenerated flow is guided from the heat exchanger to the gas-liquid separator, and spent material is separated from the cooled spent regenerated flow to generate the regenerated flow and the spent material flow. The method according to claim 19, including the method described in claim 19.

Images