Process for removal of kinetic hydrate inhibitor polymer from rich meg stream by liquid-liquid extraction

Abstract

A method includes receiving a source stream into a liquid-liquid extractor. The source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The method also includes receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives. The method also includes separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquid-liquid extraction using the extraction solvent, outputting the extract stream including the KHI actives and the extraction solvent, and outputting the raffinate stream including the rich MEG.

Description

IS25.0381-WO-PCTPROCESS FOR REMOVAL OF KINETIC HYDRATE INHIBITOR POLYMER FROM RICH MEG STREAM BY LIQUID-LIQUID EXTRACTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 694,237, filed September 13, 2024, and U.S. Provisional Application No. 63 / 782,122, filed April 2, 2025, each of which is hereby incorporated by reference in its entirety for all purposes.BACKGROUND

[0002] The present disclosure relates generally to a system and method for removal of kinetic hydrate inhibitor polymer from a rich MEG stream by liquid-liquid extraction, such that the different hydrate inhibitors can be reused in oil and gas applications.

[0003] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0004] Natural gas hydrates are ice-like structures of water and gas molecules that form inside subsea flowlines under certain conditions of pressure and temperature and significantly disrupt the flow of produced gas and the operation of the subsea facilities.

[0005] Thermodynamic Hydrate Inhibitors, such as Mono Ethylene Glycol (MEG), may be used to chemically mitigate natural gas hydrates by shifting the conditions at which gas hydrate forms. MEG may be injected in the subsea wellhead in large quantities (i.e., 30 - 70 wt.% of the produced water phase).IS25.0381-WO-PCT

[0006] Low Dosage Hydrate Inhibitors, such as Kinetic Hydrate Inhibitors (KHI), may also be used in small quantities (i.e., 1 - 3 wt.% of the produced water phase) to delay the nucleation of the gas hydrates and provide protection for a limited time. Coinjection of MEG and KHI for hydrate may have numerous benefits. These benefits may include reducing MEG dosage requirements and flow rates, which may increase gas production by debottlenecking MEG processing facilities, reducing the size of subsurface production facilities and flow lines, reducing the topside processing facilities size and duty requirements, and reducing overall greenhouse gas emissions associated with the energy usage and embodied carbon.

[0007] Despite the benefits of integrating MEG and KHI, several technical challenges have slowed the development of this technology at scale. MEG is a cheaper and recyclable chemical that can be reclaimed from the produced stream, and reinjected as a lean MEG compared to KHI, which is more expensive and considered a single-use chemical that is often discharged with the produced water.

[0008] Additionally, reclamation of MEG utilizes efficient removal of the KHI actives from a MEG stream to reduce precipitation of the polymeric actives at the operating condition of the topside facilities. Reducing precipitation may reduce equipment damage and operation interruptions. Removing the KHI from the MEG stream may be an expensive process that either requires modification on the standard MEG facilities when KHI is removed within the MEG reclamation, or generation of additional waste streams when a separate process unit is added upstream of the MEG facilities. Nevertheless, the cost of handling the single-use KHI, without the ability to reuse the KHI and the removal of chemicals, diminishes the benefits obtained from the integration of MEG and KHI.BRIEF DESCRIPTION

[0009] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.IS25.0381-WO-PCT

[0010] In certain embodiments, a method includes receiving a source stream into a liquid-liquid extractor. The source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The method also includes receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives. The method also includes separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquidliquid extraction using the extraction solvent, outputting the extract stream including the KHI actives and the extraction solvent, and outputting the raffinate stream including the rich MEG.

[0011] In certain embodiments, a system includes a liquid-liquid extractor. The liquidliquid extractor includes a source inlet configured to receive a source stream, wherein the source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The liquid-liquid extractor includes a solvent inlet configured to receive an extraction solvent, wherein the extraction solvent has an affinity for the KHI actives, a liquid-liquid extraction section configured to separate the source stream into an extract stream and a raffinate stream via a liquid-liquid extraction using the extraction solvent, an extract outlet configured to output the extract stream including the KHI actives and the extraction solvent, and a raffinate outlet configured to output the raffinate stream including the rich MEG.

[0012] In certain embodiments, a system including a controller having a processor, a memory, and instructions stored on the memory and executable by the processor to perform operations including receiving a source stream into a liquid-liquid extractor. The source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The processor may also perform operations including receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives, separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquid-liquid extraction using the extraction solvent, outputting the extract stream including the KHI actives and the extraction solvent, and outputting the raffinate stream including the rich MEG.IS25.0381-WO-PCTDRAWINGS

[0013] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0014] FIG. 1 is a block diagram of an embodiment of a mono ethylene glycol (MEG) and Kinetic Hydrate Inhibitor (KHI) processing system, in accordance with the present disclosure;

[0015] FIG. 2 is a block diagram of an embodiment of a liquid-liquid extraction unit within the MEG and KHI processing system, in accordance with the present disclosure;

[0016] FIG. 3 is a block diagram of an embodiment of a first portion of a KHI reclamation and regeneration unit, in accordance with the present disclosure;

[0017] FIG. 4 is a block diagram of an embodiment of a second portion of a KHI reclamation and regeneration unit, in accordance with the present disclosure;

[0018] FIG. 5 is a flow diagram of an embodiment of an extraction process and solvent recovery process, in accordance with the present disclosure; and

[0019] FIG. 6 is a flow diagram of an embodiment of a process corresponding to the second portion of the KHI reclamation and regeneration unit of FIG. 4, in accordance with the present disclosure.DETAILED DESCRIPTION

[0020] One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system- related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might beIS25.0381-WO-PCT complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0021] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and / or environmental conditions are not exclusive of other parameters / conditions of the disclosed embodiments.

[0022] Further, as used herein, the article “a” is intended to have its ordinary meaning in the patent arts, namely “one or more.” Herein, the term “about” when applied to a value generally means within the tolerance range of the equipment used to produce the value, or in some examples, means plus or minus 10%, or plus or minus 5%, or plus or minus 1%, unless otherwise expressly specified. Further, herein the term “substantially” as used herein means a majority, or almost all, or all, or an amount with a range of about 51% to about 100%, for example. The term “substantially free” as used herein means less than or equal to about 100 ppm, although substantially free may further include less than or equal to 100 ppm, 90 ppm, 80 ppm, 70 ppm, 60 ppm, 50 ppm, 40 ppm, 30 ppm, 20 ppm, or 10 ppm The percentage values discussed herein may correspond to weight (wt.) percentage values. Furthermore, each of the values presented below are intended to support the specific values and ranges of plus or minus 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. Moreover, examples herein are intended to be illustrative only and are presented for discussion purposes and not by way of limitation.

[0023] Additionally, "KHI" refers to the kinetic hydrate inhibitor product, which is a homogeneous liquid mixture typically made of one or more chemicals. The KHI chemical mixture is typically composed of one or more active ingredients, in addition to one or more solvents. Conversely, "KHI active” refers to a specific chemical or ingredient in the KHI that is directly responsible for hydrate inhibition. The typical KHI active is polymer but may include other chemicals such as surfactants, ionic liquid,IS25.0381-WO-PCT natural or bio-based material, or metal complexes. The KHI may consist of a single active chemical or a combination of actives for enhanced performance.

[0024] In certain embodiments as discussed in further detail below, a processing system is configured to separate and regenerate different hydrate inhibitors, such as kinetic hydrate inhibitor (KHI) polymers and Mono Ethylene Glycol (MEG), for reuse in oil and gas applications. The processing system may receive and process an aqueous stream having both KHI and MEG, which may be described as a Rich MEG aqueous stream (e.g., Rich MEG stream). For example, the Rich MEG stream may be an aqueous stream produced through natural gas pipelines. The Rich MEG stream includes a bulk of water and / or mono ethylene glycol (MEG) along with low dosages of flow assurance chemicals. The flow assurance chemicals may include KHI, Corrosion Inhibitors (CI), Scale Inhibitors (SI), or any combination thereof. In particular, the processing system enables separation of the KHI from the rich MEG via a Liquid-Liquid-Extraction (LLE) unit, thereby generating a first stream (e.g., MEG stream) and a second stream (e.g., KHI stream). The KHI stream is routed to a KHI reclamation and regeneration system, which is configured to regenerate the KHI for further use. Similarly, the MEG stream is routed to a MEG reclamation and regeneration system, which is configured to regenerate the MEG for further use.

[0025] This disclosure describes an architecture of connected process units that provides a system and method for removing KHI actives from the Rich MEG stream of natural gas production. The process provides a retrofittable pretreatment system to a MEG Reclamation Units (MRU) to minimize KHI actives that may be incompatible with the MEG recovery processes. Some embodiments describe an architecture of open art equipment connected and built as an integrated unit. The process is system-level and specifically focuses on applying the integrated equipment system to remove KHI actives from the Rich MEG stream.

[0026] As discussed below, the Rich MEG stream may be processed in a plurality of stages of chemical and mechanical treatments for the MEG regeneration and the KHI regeneration. For example, the system may include one or more pre-treatment units configured to pre-treat the Rich MEG stream, such as by removing solids and / or impurities. After pre-treatment, the system may include the LLE unit configured to separate the Rich MEG stream into the first stream (e.g., MEG stream) and the secondIS25.0381-WO-PCT stream (e.g., KHI stream). The processing system facilitates the removal of KHI actives by liquid-liquid extraction principles in the LLE unit, where the saturated Rich MEG comes into contact with an extraction solvent with a high distribution coefficient to extract the KHI actives. For example, the Rich MEG stream is treated with a water immiscible extraction solvent that may extract the polymeric actives including the KHI actives. The extraction solvent may be any hydrocarbon solvent that is immiscible with the water-MEG mixture and has a partitioning coefficient adequate to facilitate the extraction process and transfer the dissolved KHI actives from the water-MEG mixture into the extraction solvent. Transferring dissolved KHI actives from the water-MEG mixture into the solvent creates two liquid layers that may be separated by any suitable means. The core process is a solvent extraction unit; however, the present disclosure provides an integrated system that pretreats the Rich MEG stream via pre-treatment units to improve the extraction performance and subsequent downstream processes to recover and recycle the MEG and the KHI. After the LLE unit, the KHI stream is further processed in the KHI reclamation and regeneration system, whereas the MEG stream is further processed in the MEG reclamation and regeneration system.

[0027] In certain embodiments, the KHI reclamation and regeneration system relates to a method for the regeneration of KHI from a bulk organic solvent feed following a solvent extraction step at which a Rich MEG stream that was produced from hydrocarbon production fields has undergone a treatment process to remove KHI actives, as described above with reference to the LLE unit. The KHI reclamation and regeneration system also provides a method for recovering the solvent that has been used in the KHI removal process. The KHI reclamation and regeneration system includes multiple stages of chemical and mechanical treatments for the regeneration of KHI raw material for product reformulation.

[0028] As highlighted above, the KHI reclamation and regeneration system is a method for regeneration of the KHI raw material for reuse in gas hydrate inhibition from a feed of a bulk organic solvent and recovery of the bulk solvent for recycling. The feed is a product of the KHI removal process using the LLE unit in which the extraction solvent was used to extract the KHI actives from a water-MEG stream that is produced from gas fields.IS25.0381-WO-PCT

[0029] The embodiments described below involve using a boiler and a distillation column operating under a vacuum to evaporate the bulk solvent under a controlled temperature and generate a high-purity overhead solvent that is recycled for the KHI removal process. The boiler bottom product is in a concentrated polymeric active material dissolved in the minimum amount of solvent that is enough to keep the product liquid. The concentrated product is further purified to remove non-KHI actives before being directed to a KHI reclamation step at which the KHI actives is redissolved in solvents that are used in the original KHI product thus producing a KHI raw material. The raw materials may be directed to a KHI reformulation step where the final KHI product, suitable for blending with the lean MEG for hydrate inhibition, is regenerated.

[0030] Various aspects of the liquid-liquid extraction process and subsequent processing of the KHI stream in the KHI reclamation and regeneration system and subsequent processing of the MEG stream in the MEG reclamation and regeneration system are discussed in further detail below with reference to FIGS. 1-6.

[0031] FIG. 1 is a block diagram of a MEG and KHI processing system 10. The processing system 10 receives a Rich MEG feed stream 12, which may include MEG, water, salts, one or more KHI, flow assurance chemicals, other free and dissolved organic and inorganic species, or a combination thereof. The Rich MEG feed stream 12 may be extracted from an oil and gas system, such as a wellsite, a pipeline, a pumping station, a compression station, or any combination thereof. The Rich MEG feed stream 12 may be directed to a liquid-liquid extraction system 16, which may include a plurality of subsystems to pretreat and separate the MEG and the KHI in the Rich MEG feed stream 12. For example, the Rich MEG feed stream 12 may be filtered in one or more filter stages before contacting an extraction solvent in one or more liquid-liquid extraction stages. The extraction solvent may be recycled in a recycled solvent stream 14 from the liquid-liquid extraction system 16 back to the liquid-liquid extraction system 16. The details of the liquid-liquid extraction system 16 are discussed in further detail below in the description of FIG. 2.

[0032] The liquid-liquid extraction system 16, upon completing one or more liquidliquid extraction stages, generates and outputs first and second streams. The first stream leaving the liquid-liquid extraction system 16 is a feed stream 18 directed to a KHI reclamation and regeneration system 20. The feed stream 18 includes the KHI and theIS25.0381-WO-PCT extraction solvent. The KHI reclamation and regeneration system 20 is configured to reclaim and regenerate KHI from the feed stream 18, thereby producing a reformulated KHI stream 22 as discussed in further detail below in the descriptions of FIGS. 3 and 4. The second stream leaving the liquid-liquid extraction system 16 is a treated rich MEG (reduced KHI) stream 26 directed to a MEG reclamation and regeneration system 24. The treated Rich MEG stream 26, as a result of the liquid-liquid extraction, may be at least reduced in KHI, substantially free of KHI, or free of KHI. For example, the liquid-liquid extraction system 16 may reduce the KHI in the treated Rich MEG stream 26 relative to the Rich MEG feed stream 12 by at least 90%, 95%, 96%, 97%, 98%, or 99%. The MEG reclamation and regeneration system 24 is configured to reclaim and regenerate MEG from the treated Rich MEG stream 26, thereby producing a lean MEG stream 28. The processing system 10 routes the reformulated KHI stream 22 from the KHI reclamation and regeneration system 20 to a blending unit 30, and further routes the lean MEG stream 28 from the MEG reclamation and regeneration system 24 to the blending unit 30. The blending unit 30 is configured to blend the reformulated KHI stream 22 with the lean MEG stream 28 to produce a lean MEG and KHI stream 32. The processing system 10 may further store and / or route the lean MEG and KHI stream 32 to one or more oil and gas systems to inhibit hydrate formation. The processing system 10 may include one or more processing units, where each processing unit may be a distillation column, centrifuge, mixer, membrane, or the like designed to carry out a process related to the processing system 10.

[0033] Further, processing system 10 includes and / or communicatively couples to one or more processor-based computing systems, such as one or more controllers 34. As illustrated, the controller 34 includes a processor 36, a memory 38, and instructions 40 stored on the memory 38 and executable by the processor 36 to control various components of the processing system 10. In certain embodiments, one or more controllers 34 may be coupled to the various components and subsystems of the processing system 10, as illustrated and described with reference to FIGS. 1-4. In certain embodiments, the controller 34 receives sensor feedback from sensors within, upstream, and downstream of the liquid-liquid extraction system 16, the KHI reclamation and regeneration system 20, the MEG reclamation and regeneration system 24, and the blending unit 30. The sensors may include temperature sensors, pressure sensors, flow rate sensors, fluid composition sensors, or any combination thereof. Thus,IS25.0381-WO-PCT the controller 34 is configured to monitor the temperature, the pressure, the flow rate, and the fluid composition throughout the processing system 10, and make adjustments to the flow rate (e.g., via valves, pumps, etc.), adjustments to the temperature (e.g., via heat exchangers, heaters, coolers, etc.), adjustments to the pressure (e.g., via pumps, compressors, pressure regulators, etc.), and adjustments to the fluid composition. For example, the controller 34 may adjust a flow rate and / or fluid composition of the extraction solvent, and in turn adjust a fluid composition of the feed stream 18 and the treated Rich MEG stream 26. Similarly, the controller 34 may adjust the temperature, pressure, flow rate, etc. in the KHI reclamation and regeneration system 20 and the MEG reclamation and regeneration system 24 to adjust the fluid composition of the reformulated KHI stream 22 and the lean MEG stream 28, respectively. In certain embodiments, the controller 34 may control various components and operating parameters (e.g., temperature, pressure, flow rate, etc.) of the processing system 10 in real-time during operation based on the sensor feedback, computer models, and user input, thereby helping to maintain the operating parameters (e.g., fluid compositions of various streams) within desired thresholds (e.g., between upper and lower concentration thresholds). The controller 34 may control all flows into, through, and out of the components, and also operations within the components of each system figure. Various aspects of the processing system 10 are discussed in further detail below with reference to FIGS. 2-6.

[0034] FIG. 2 is a block diagram of an embodiment of the liquid-liquid extraction system 16 of the processing system 10 of FIG. 1. As described above, the processing system 10 receives a rich MEG feed stream 12, which may include MEG, water, salts, one or more KHI, flow assurance chemicals, other free and dissolved organic and inorganic species, or a combination thereof. In the illustrated embodiment, the liquidliquid extraction system 16 includes a fluid circuit 42 having various flow paths 44 through a pretreatment unit 50, a waste collection 54, a liquid-liquid extraction unit 58, a raffinate treatment unit 62, a MEG reclamation and regeneration system 24, a solvent storage 68, and a solvent recovery system 20a (e.g., first portion of KHI reclamation and regeneration system 20). The fluid circuit 42 also includes various supporting equipment (e.g., valves, sensors, pumps, compressors, tanks, heat exchangers, heaters, coolers, condensers, etc.) along the various flow paths 44 upstream, within, and / or downstream of the various components (e.g., 50, 54, 58, 62, 24, 68, and 20a).IS25.0381-WO-PCTAdditionally, the liquid-liquid extraction system 16 includes the controller 34 coupled to the various supporting equipment and the various components, wherein the controller 34 is configured to monitor the various components and sensors and control the various components and supporting equipment to perform all processes associated with the liquid-liquid extraction.

[0035] For example, the rich MEG feed stream 12 may be directed to a pretreatment unit 50 to filter and remove suspensions, solids, and other free species not chemically bound to the main rich MEG chemicals. For example, the pretreatment unit 50 may remove suspensions and solids such that the remaining species do not do not interrupt the liquid-liquid extraction process. The pretreatment unit 50 may include one or more types of filtration systems, such as bag filters, clean-in-place filters, cartridge filters, high-flow filters, membranes, multimedia filters, or any filters that operate with or without precoating. The pretreatment unit 50 also may include one or more types of separators, such as centrifugal separators, gravity separators, and / or mechanical separators. The pretreatment unit 50 may operate at a controlled temperature below the cloud point of the KHI product to help substantially reduce or avoid deposition of the active material. The pretreatment unit 50 separates the rich MEG feed stream 12 into a filtered Rich MEG stream 56 and a solid waste stream 52. The solid waste stream 52 may be directed from the pretreatment unit 50 to a waste collection 54 for processing and disposal. The filtered Rich MEG stream 56 may be directed from the pretreatment unit 50 to a liquid-liquid extraction unit 58. The liquid-liquid extraction unit 58 may include a liquid-liquid extraction section configured to separate the source stream into an extract stream and a raffinate stream via liquid-liquid extraction using the extraction solvent. The liquid liquid extraction unit 58 may also include an extract outlet configured to output the extract stream comprising the KHI and the extraction solvent and a raffinate outlet configured to output the raffinate stream comprising the rich MEG.

[0036] The liquid-liquid extraction unit 58 contacts the filtered Rich MEG stream 56 with an extraction solvent stream 74 in one or more liquid-liquid extraction stages, thereby generating the feed stream 18 (e.g., KHI actives and extraction solvent) and a raffinate liquid stream 60. The liquid-liquid extraction system 16 supplies the extraction solvent stream 74 to the liquid-liquid extraction unit 58 via a solvent storageIS25.0381-WO-PCT68 and one or more pumps and / or a gravity feed. The extraction solvent in the extraction solvent stream 74 may include fatty alcohols, fatty acids, fatty amines, alcohol, amine, ether, carboxylic acid, diols, triols, and polyols or any liquid with a suitable distribution coefficient to extract the KHI active from the filtered rich MEG stream 56 and the desired chemical and physical properties, which provide for phase separation with miscibility in the filtered rich MEG stream 56. The extraction solvent generally has an affinity for KHI, but not an affinity for MEG. Further, the extraction solvent stream 74 may be a combination of a solvent distillate stream 72, which is further described in the description of FIG. 3, and a solvent 70 retrieved from a raffinate treatment unit 62. The specific composition of the extraction solvent stream 74 may be based on the composition of the solvent distillate stream 72 and its amount, the composition of the solvent 70 and its amount, or a combination thereof.

[0037] The filtered rich MEG stream 56 and the extraction solvent stream 74 may be preheated upstream of the liquid-liquid extraction unit 58. Both the filtered rich MEG stream 56 and the extraction solvent stream 74 may be introduced to the liquidliquid extraction unit 58 at a temperature below the cloud point of the targeted solute. In some embodiments, the targeted solute is the KHI active polymer. The heat provided to the liquid-liquid extraction unit 58 may be supplied by any suitable heating system, such as heating within the pretreatment unit 50 and solvent storage 68, through dedicated in-line heating equipment upstream of the liquid-liquid extraction unit 58, or the like. For example, the heating system may include a heat exchanger, an electrical heater, a combustion heater or boiler, or any combination thereof.

[0038] The liquid-liquid extraction unit 58 may facilitate the mass transfer of bulk KHI actives (e.g., solute) from the rich MEG into the extraction solvent. The primary purpose of the liquid-liquid extraction unit 58 may be to bring the filtered rich MEG stream 56 and the extraction solvent stream 74 into contact and establish the conditions to efficiently transfer the bulk KHI actives (e.g., solute) and provide for phase separation.

[0039] In some embodiments, the core of the liquid-liquid extraction unit 58 may include one piece of equipment to mix and separate the phases. In other embodiments, the core of the extraction unit 58 may include a piece for the mixing and a separate piece for the phase separation. In either embodiment, the extraction process of theIS25.0381-WO-PCT liquid-liquid extraction unit 58 may be accomplished in one stage or in multiple stages using two or more systems. The number of stages and systems used by the liquid-liquid extraction unit 58 may be based on the target purity of the Rich MEG.

[0040] In embodiments with extraction using one piece of equipment, the process may use equipment such as extraction columns (e.g., static extraction columns, dynamic extraction columns, extraction columns with different internal machinery, and the like), mixer-settlers, centrifugal extractors, or any other unit configured to receive two inlet streams (i.e., feed and solvent) and produce two outlet streams (i.e., extract and raffinate) through a liquid-liquid extraction process.

[0041] For embodiments performing extraction using multiple pieces of equipment, the liquid-liquid extraction process may use a mixer and a physical separator in sequence. The mixing unit may operate using any mixing systems, such as dynamic mixing systems, static mixing systems, vibration mixing systems, high-shear mixing systems, pneumatic mixing systems, or the like. The mixing may bring the two inlet streams into contact to establish the desired equilibrium conditions to facilitate the mass transfer. The separation unit of the liquid-liquid extraction unit 58 may receive the output of the mixing unit as a liquid mixture and facilitate the phase separation. The separation equipment of the liquid-liquid extraction unit 58 may include gravity -based separators, membrane separators, and coalescers.

[0042] The liquid-liquid extraction unit 58 may operate at a controlled temperature and pressure condition to establish the desired mass transfer conditions and may generate two main output streams. The first stream that leaves the liquid-liquid extraction unit 58 is a raffinate liquid. Specifically, the raffinate liquid stream 60 may be the treated Rich MEG with a reduced concentration of KHI actives and entrained solvent.

[0043] To further purify the Rich MEG and recover more solvent, the raffinate liquid stream 60 is sent to a raffinate treatment unit 62, which may facilitate the removal of entrained extraction solvent from the treated Rich MEG. The raffinate treatment unit 62 may be a distillation column, a stripping column, a liquid membrane, a centrifuge, or any suitable process equipment. In some embodiments, the raffinate treatment unit 62 may be a batch process. In other embodiments, the raffinate treatment unit 62 mayIS25.0381-WO-PCT be a continuous process. Further, while the raffinate treatment unit 62 may operate at atmospheric pressure in some embodiments, the raffinate treatment unit 62 may operate under vacuum in other embodiments. Further, the raffinate treatment unit 62 may operate either in one stage or in multiple stages.

[0044] The raffinate treatment unit 62 may generate at least two steams, including a recovered solvent 70. The recovered solvent 70 may be routed back to solvent storage 68. In certain embodiments, the recovered solvent 70 may be at high purity solvent having low amounts of other materials and impurities. The term “high purity” as used herein means less than or equal to about 95% solvent, although substantially free may further include greater than or equal to 95%, 96%, 97%, 98%, or 99%. The raffinate treatment unit 62 may also generate a stream of treated Rich MEG stream 26 with no or minimal entrained solvent and KHI. For example, the treated Rich MEG stream 26 may be at least reduced in extraction solvent and KHI, substantially free of extraction solvent and KHI, or free of extraction solvent and KHI. In certain embodiments, the treated Rich MEG stream 26 may have levels of the extraction solvent and KHI below threshold levels acceptable for processing the MEG in the MEG reclamation and regeneration unit 24. The raffinate treatment unit 62 may also have equipment with auxiliary facilities, including heat-supply equipment (e.g., heat exchanger, heater, reboiler, etc.), condensation equipment, reflux collection vessels, or the like. The auxiliary facilities may be separated or shared with the auxiliary equipment of a liquidliquid extractor 58. The treated Rich MEG stream 26 may leave the raffinate treatment unit 62 and the liquid-liquid extraction system 16 may send the treated Rich MEG stream 26 to a separate unit, such as the MEG reclamation and regeneration unit 24 or other pretreatment units.

[0045] In the first step of the MEG reclamation and regeneration unit 24, a stream having MEG and water and other impurities is fed into a flash separator or an evaporator operating under partial vacuum. In the flash separator, feed is instantaneously vaporized. The heating duty for the flash separator to completely vaporize MEG and water is provided by a large recycle stream, which is heated in a heat exchanger using a heating medium to provide sufficient energy to fully vaporize the MEG and water components of the feed stream.IS25.0381-WO-PCT

[0046] In the next step of the MEG reclamation and regeneration unit 24, an overhead water vapor stream from the flash separator having MEG and water is fed to a refluxed distillation column with a reboiler, whereby water having a lower boiling point is distilled from the MEG and the water vapor stream. The vaporized water from the distillation column overhead is then condensed and collected in a reflux drum and a small amount of the condensed water is returned to the distillation column. The bottom part of the distillation column may produce MEG and pump the MEG to a collection tank. As such, MEG and water are separated and recovered with high purities, such that it can be reused as pure MEG and distilled water.

[0047] In the flash separator of the first step, the dissolved and suspended solids and contaminants being non-volatile are precipitated and settled by gravity towards the bottom of the separator, and removed, washed, centrifuged, filtered or separated by any other methods / techniques for solids separation. The solids / slurry of the MEG reclamation and regeneration unit 24 are transferred to a solids tank to further concentrate before being directed to a centrifuge.

[0048] The second stream output by the liquid-liquid extraction unit 58 is the feed stream 18, which includes the extraction solvent along with the extracted KHI active. As illustrated, the feed stream 18 is routed from the liquid-liquid extraction unit 58 to a solvent recovery system 20a, which is a first portion of the KHI reclamation and regeneration system 20 of FIG. 1. The composition of the feed stream 18 may include extraction solvent, KHI actives, water, MEG, assorted organic materials, and suspended solids. The extraction solvent may be about 70-95% of the composition of the feed stream 18. The KHI active materials may be about 3-15% of the composition of the feed stream 18. The water and MEG each may be about 0.5-5% of the composition of the feed stream 18. Further, the water and MEG may either be dissolved into the feed stream 18, or may be free floating. The feed stream 18 may also include about 0.5-3% dissolved or free floating assorted organic materials, such as hydrocarbons, condensate, or oil. While the pretreatment unit 50 may remove most suspended solids from the rich MEG feed stream 12, the feed stream 18 may still include between about 0.5-2% suspended solids. The percentage of each component of the feed stream 18 may depend on the operating parameters of the pretreatment unit 50, liquid-liquid extraction unit 58,IS25.0381-WO-PCT raffinate treatment unit 62, the starting composition of the rich MEG feed stream 12, the target composition of the feed stream 18, or a combination thereof.

[0049] As discussed in further detail below, the solvent recovery system 20a is configured to separate the feed stream 18 into a solvent distillate stream 72 (e.g., recovered extraction solvent) and a bottom product 120 (e.g., concentrated KHI stream). The liquid-liquid extraction system 16 recycles or recirculates the solvent distillate stream 72 back to the solvent storage 68, and thus supports the liquid-liquid extraction process in the liquid-liquid extraction unit 58. The liquid-liquid extraction system 16 routes the bottom product 120 (e.g., concentrated KHI stream) to one or more additional stages or systems of the KHI reclamation and regeneration system 20, such as a second portion of the KHI reclamation and regeneration system 20b as illustrated in FIG. 4. The solvent recovery system 20a is now discussed with reference to FIG. 3.

[0050] FIG. 3 a block diagram of an embodiment of the solvent recovery system 20a of FIG. 2, which is the first portion of the KHI reclamation and regeneration system 20 of FIG. 1. In the illustrated embodiment, the solvent recovery system 20a includes a fluid circuit 90 having various flow paths 92 through a distillation unit 100, a condenser 104, a reflux drum 108, a vacuum system 118, a reboiler 116, a storage tank 122, and a second portion of the KHI reclamation and regeneration system 20b. The fluid circuit 90 also includes various supporting equipment (e.g., valves, sensors, pumps, compressors, tanks, heat exchangers, heaters, coolers, condensers, etc.) along the various flow paths 92 upstream, within, and / or downstream of the various components (e.g., 100, 104, 108, 118, 116, 122, and 22b). Additionally, the solvent recovery system 20a includes the controller 34 coupled to the various supporting equipment and the various components, wherein the controller 34 is configured to monitor the various components and sensors and control the various components and supporting equipment to perform all processes associated with the solvent recovery.

[0051] The feed stream 18 may be separated into the solvent distillate stream 72 (e.g., recovered extraction solvent) and the bottom product 120 (e.g., concentrated KHI stream) using the solvent recovery system 20a. The solvent recovery system 20a may be a distillation process that separates the solvent from the solute. The solvent recovery system 20a includes a distillation unit 100 (e.g., a distillation column) configured to distill the feed stream 18 and generate a minimum of two streams. The first streamIS25.0381-WO-PCT generated by the distillation unit 100 may be high-purity overhead solvent vapor stream 102 routed back into the solvent storage 68 via a solvent distillate stream 72 for recycling after passing through a condenser 104 and reflux drum 108. The second stream generated by the distillation unit 100 may be a column liquid stream 112 including the extracted KHI actives dissolved in the extraction solvent. The second stream generated by the distillation unit 100 is sent to a storage tank 122 and / or the second portion of the KHI reclamation and regeneration system 20b as illustrated in FIG. 4. The column liquid stream 112 is further described below.

[0052] In some embodiments, the distillation unit 100 may be a batch process. In other embodiments, the distillation unit 100 may be a continuous process. Further, while the distillation unit 100 may operate at atmospheric pressure in some embodiments, the distillation unit 100 may operate under vacuum in other embodiments. The configuration of the distillation unit 100 may be based on the operating targets of the system. The distillation unit 100 may be equipped with auxiliary facilities, including heat-supply equipment (e.g., heat exchanger, heater, reboiler, etc.), condensation equipment, reflux collection vessels, and the like.

[0053] The solvent recovery system 20a uses a reboiler 116 and a distillation unit 100 operating under a vacuum to evaporate the bulk solvent under a controlled temperature and generate a high-purity overhead solvent vapor stream 102 that is recycled for the KHI removal process. The high-purity overhead solvent vapor stream 102 may include extraction solvent, water, MEG, and other hydrocarbons. The solvent vapor may be about 90-99% of the composition of the high-purity overhead solvent vapor stream 102. The water and MEG may be about 0.5-5% and about 0.3-4% of the composition of the high-purity overhead solvent vapor stream 102, respectively. The high-purity overhead solvent vapor stream 102 may also include about 0.2-1% other hydrocarbons, such as MEG or other vaporized organics from the free / dissolved hydrocarbon condensate and oil The percentage of each component of the high-purity overhead solvent vapor stream 102 may depend on the operating parameters of the distillation column 100, the operating parameters of the reboiler 116, the operating parameters of the condenser 104, the operating parameters of the reflux drum 108, the starting composition of the feed stream 18, the target composition of the bottom product 120, or a combination thereof.IS25.0381-WO-PCT

[0054] The high-purity overhead solvent vapor stream 102 may then enter a condenser 104. The condenser 104 may condense the high-purity overhead solvent vapor stream 102 into a high-purity overhead solvent liquid stream 106. The high- purity overhead solvent liquid stream 106 may then flow into a reflux drum 108. The reflux drum 108 may collect the high-purity overhead liquid solvent and split the high- purity overhead liquid solvent into two streams. The top stream may be the solvent distillate stream 72. The solvent in the solvent distillate stream 72 may include extraction solvent, water, MEG, and other hydrocarbons. The solvent distillate stream 72 may be about 97-99% of the composition of the solvent distillate stream 72. The water and MEG each may be about 0.5-1% of the composition of the solvent distillate stream 72. The solvent distillate stream 72 may also include about 0-1% other hydrocarbons, which may be the same hydrocarbons in the overhead vapor solvent stream 102. The percentage of each component of the solvent distillate stream 72 may depend on the operating parameters of the distillation column 100, the operating parameters of the reboiler 116, the operating parameters of the condenser 104, the operating parameters of the reflux drum 108, the starting composition of the feed stream 18, the target composition of the bottom product 120, or a combination thereof.

[0055] The bottom stream, however, may be the reflux stream 110, which flows back into the distillation unit 100. The reflux stream 110 may include solvent, water, MEG, and other hydrocarbons. The solvent may be about 90-99% of the composition of the reflux stream 110. The water and MEG may be about 0.5-5% and about 0.3-4% of the composition of the reflux stream 110, respectively. The reflux stream 110 may also include about 0.2-1% other hydrocarbons, which may be the same hydrocarbons as the hydrocarbons in the solvent distillate stream 72. The percentage of each component of the high-purity overhead solvent vapor stream 102 may depend on the operating parameters of the distillation column 100, the operating parameters of the reboiler 116, the operating parameters of the condenser 104, the operating parameters of the reflux drum 108, the starting composition of the feed stream 18, the target composition of the bottom product 120, or a combination thereof.

[0056] Connected to the reflux drum 108 may be a vacuum system 118. The vacuum system 118 may assist the reflux drum 108, the condenser 104, or both, with evaporating the solvent from the high-purity overhead solvent stream 102. Specifically,IS25.0381-WO-PCT by decreasing the pressure of the solvent recovery system 20a, the vacuum system 118 may assist the solvent to evaporate at a lower temperature, which saves heat duty for the solvent recovery system 20a. As such, the solvent recovery system 20a may evaporate more solvent into the solvent distillate stream 72 from the high-purity overhead solvent stream 102, so the reflux stream 110 may include a lower percentage of solvent as it returns to the distillation unit 100. In some embodiments, the vacuum system 118 is part of the MEG reclamation and regeneration unit 24 to efficiently utilize existing equipment.

[0057] The reboiler bottom product 120 is a concentrated polymeric active material dissolved in a low or minimum amount of solvent that is enough to keep the product liquid. The concentrated product may be further purified to remove non-KHI actives before being directed to a reversed extraction step illustrated in FIG. 4 at which the KHI actives may be redissolved in solvents used in the KHI formation. As such, the process may produce a KHI raw material.

[0058] In one embodiment, the method for regeneration of the KHI raw materials begins by processing a feed stream 18 of a solvent saturated with at least one KHI polymeric active (e.g., less than 20 vol%) and no or minimal MEG and water. The column liquid 112 may be a separated product of the solvent recovery system 20a using a water-immiscible solvent primarily used to extract KHI polymeric actives from a MEG stream produced from hydrocarbon fields. Specifically, the column liquid 112 may be a combination of the feed stream 18 and the reflux stream 110, of which the compositions of both are described above.

[0059] After exiting the distillation column 100, the column liquid 112 may be directed into a reboiler 116. The reboiler 116 may concentrate the KHI actives and leave the minimum amount of solvent creating a bottom product 120 and a boil vapor 114. The boil vapor 114 may be a combination of the feed stream 18 and the reflux stream 110. The composition of the boil vapor 114 may depend on the composition of the feed stream 18, the composition of the reflux stream 110, the operating parameters of the distillation unit 100, the operation of the reboiler 116, the composition of the bottom product 120, and the like.IS25.0381-WO-PCT

[0060] The bottom product 120, which may be a concentrated solvent-polymeric actives stream, is then passed to storage tank 122 before the process directs the bottom product 120 to the second portion of the KHI Reclamation and regeneration system 20b. Specifically, the bottom product 120 may include extraction solvent, KHI active material, water, MEG, and assorted organic materials. The extraction solvent may be about 60-70% of the composition of the bottom product 120. The KHI active materials may be about 10-30% of the composition of the bottom product 120. The water and MEG may be about 0-1% and 0.5-2% of the composition of the bottom product 120, respectively. Further, the water and MEG may either be dissolved into the bottom product 120, or may be free floating. The bottom product 120 may also include about 0.5-5% dissolved or free floating assorted organic materials, which may include the same assorted organic materials as the feed stream 18. The percentage of each component of the bottom product 120 may depend on the operating parameters of the distillation column 100, the operating parameters of the reboiler 116, the operating parameters of the condenser 104, the operating parameters of the reflux drum 108, the starting composition of the feed stream 18, the target composition of the bottom product 120, or a combination thereof.

[0061] FIG. 4 is a block diagram of an embodiment of the second portion of the KHI reclamation and regeneration system 20b of FIGS. 1-3. In particular, the KHI reclamation and regeneration system 20b of FIG. 4 follows the KHI reclamation and regeneration system 20a of FIG. 3, wherein the KHI reclamation and regeneration system 20a and 20b collectively form the KHI reclamation and regeneration system 20 of FIG. 1. The second portion of a KHI reclamation and regeneration system 20b may be on-site or off-side depending on the goals of the process. In the illustrated embodiment, the KHI reclamation and regeneration system 20b includes a fluid circuit 140 having a flow path 142 through a purification unit 150, the KHI reclamation unit 158, a KHI reformulation unit 164, a storage tank 168, and the blending unit 30. The fluid circuit 140 also includes a plurality of valves 144 (e.g., 178, 180, and 182) and sensors 156 (e.g., 156a, 156b, and 156c) disposed along the flow path 142 upstream, within, and / or downstream of the various components. Additionally, the KHI reclamation and regeneration system 20b includes the controller 34 coupled to the valves 144, the sensors 156, and the various components (e.g., purification unit 150, KHI reclamation unit 158, KHI reformulation unit 164, storage tank 168, and blendingIS25.0381-WO-PCT unit 30). The controller 34 is configured to monitor the various components and sensors 156 and control the valves 144 and various components to perform the reclamation and regeneration of the KHI from the bottom product 120.

[0062] To begin the second portion of the KHI reclamation and regeneration system 20b, the bottom product 120 may be passed to through the purification unit 150 to remove at least a substantial portion or all of non-KHI polymers. The purification unit 150 is an optional unit, which may not be present in every embodiment based on the target operation parameters and product composition of the process. The purification unit 150 may be any unit designed to further remove any unwanted components of the bottom product 120 before the bottom product 120 is directed to the KHI reclamation unit 117. For example, the purification unit 150 may remove some or substantially all of the free and dissolved organics, free and dissolved MEG, free and dissolved water, or a combination thereof, from the bottom product 120. As such, the purification unit 150 may include a membrane, a centrifuge, an additional distillation column, or any combination thereof. Further, in some embodiments, the purification unit 150 may include multiple pieces of equipment to reduce or eliminate multiple components from the bottom product composition.

[0063] The purification unit 150 may have two exit streams. The first exit stream may be process waste stream 152. The product waste stream 152 may include the components removed from the bottom product 120 in the purification unit 150. The second exit stream may be the purified bottom product stream 154. The purified bottom product stream 154 may be about 70-80% extraction solvent and about 20-40% KHI active material. The purified bottom product stream 154 may also include trace amounts of water, MEG, other organics, or a combination thereof, based on the system’s tolerance.

[0064] Along the flow path of the purified bottom product stream 154 may be sensors 156a. In certain embodiments, the sensors 156a include temperature sensors, pressure sensors, flow rate sensors, and fluid composition sensors, thereby enabling measurements of temperature, pressure, flow rate, and fluid composition of the purified bottom product stream 154. For example, the sensors 156a may include at least one fluid composition sensor configured to obtain measurements to analyze the composition (e.g., percentage or concentration of various components) of the purified bottomIS25.0381-WO-PCT product stream 154. If the sensors 156a detects the purified bottom product stream 154 meets the threshold target composition, then the controller 34 may control a valve 178 to direct a flow of the purified bottom product stream 154 to the KHI reclamation unit 158, as described in more detail below. However, if the sensors 156a detects the purified bottom product stream 154 does not meet the threshold target composition, then the controller 34 may control the valve 178 to direct at least a portion or all of the flow of the purified bottom product stream 154 along a recirculation flow path 179 back to the purification unit 1150 to further purify the purified bottom product stream 154. In embodiments in which there are multiple pieces of process equipment (e.g., centrifuges, distillation columns, etc.) in the purification unit 150, the system may direct the purified bottom product stream 154 to the pieces of operating equipment configured to reduce the presence of the one or more components which are outside of the desired threshold amount for those components. This process may be repeated until the purified bottom product 154 meets the threshold purity targets for the process. Once the purified bottom product 154 meets the threshold purity targets for the process, then the controller 34 may control the valve 178 to direct the purified bottom product 154 to the KHI reclamation unit 158.

[0065] In certain embodiments, the controller 34 adjusts a position of the valve 178 to direct at least a portion of the purified bottom product stream 154 along the recirculation flow path 179 until each component of the fluid composition is generally steady within desired thresholds. However, the controller 34 may generally hold and / or continuously vary the position of the valve 178 to maintain at least some recirculation flow of the purified bottom product stream 154 and at least some flow of the purified bottom product stream 154 to the KHI reclamation unit 158. The KHI reclamation and regeneration system 20b may provide similar control for the temperature, pressure, flow rate, and fluid composition.

[0066] Once the purified bottom product 154 meets the threshold target composition for the process, the valve 178 may direct all or part of the purified bottom product 154 to the KHI reclamation unit 158. To reclaim the KHI, the KHI reclamation unit 158 may include a chemical reclamation system (e.g., a reversed liquid-liquid extraction), a mechanical reclamation system (e.g., a membrane or a centrifuge), a thermal reclamation system (e.g., an evaporation or distillation column), or a combinationIS25.0381-WO-PCT thereof. The KHI reclamation unit 158 may be one or more reclamation subsystems or stages configured to transfer the KHI actives from the extraction solvent 72 into another solvent used in the KHI reformulation unit 120 described below.

[0067] Transferring the KHI actives from the extraction solvent 72 into another solvent may generate a raw KHI material. The transfer process may be a single or multi-stage reversed solvent extraction process or a combination of solvent extraction and mechanical processes that generates raw KHI material with minimal loss of actives. As such, the KHI reclamation unit 158 may include two exit streams. The exit streams may include a process waste stream 160 and a reclaimed KHI stream 162. The process waste stream 160 may include unwanted solvent removed from the process in the KHI reclamation unit 158. Conversely, the reclaimed KHI stream 162 may include about 50-80% KHI original solvent and about 20-50% KHI active material.

[0068] Along the flow path of the reclaimed KHI stream 162 may be sensors 156b. In certain embodiments, the sensors 156b include temperature sensors, pressure sensors, flow rate sensors, and fluid composition sensors, thereby enabling measurements of temperature, pressure, flow rate, and fluid composition of the reclaimed KHI stream 162. The sensors 156b may include at least one fluid composition sensor configured to analyze the composition (e.g., percentage or concentration of various components) of the reclaimed KHI stream 162. Further, the sensors 156b may be substantially similar in operation to sensors 156a. If the sensors 156a detects the reclaimed KHI stream 162 meets the threshold target composition, then the controller 34 may control the valve 180 to direct a flow of the reclaimed KHI stream 162 to the KHI reformulation unit 164, as described in more detail below. However, if the sensors 156b detects the reclaimed KHI stream 162 does not meet the threshold target composition, then the controller 34 may control the valve 180 to direct at least a portion or all of the flow of the reclaimed KHI stream 162 along a recirculation flow path 181 back to the KHI reclamation unit 158 to further purify the reclaimed KHI stream 162. This process may be repeated until the reclaimed KHI stream 162 meets the threshold composition targets for the process. Once the reclaimed KHI stream 162 meets the threshold composition targets for the process, then the controller 34 may control the valve 180 to direct the reclaimed KHI stream 162 to the KHI reformulation unit 164.IS25.0381-WO-PCT

[0069] In certain embodiments, the controller 34 adjusts a position of the valve 180 to direct at least a portion of the reclaimed KHI stream 162 along the recirculation flow path 181 until each component of the fluid composition is generally steady within desired thresholds. However, the controller 34 may generally hold and / or continuously vary the position of the valve 180 to maintain at least some recirculation flow of the reclaimed KHI stream 162 and at least some flow of the reclaimed KHI stream 162 to the KHI reformulation unit 164. The KHI reclamation and regeneration system 20b may provide similar control for the temperature, pressure, flow rate, and fluid composition.

[0070] Once the reclaimed KHI stream 162 meets the threshold target composition for the process, the valve 180 may direct all or part of the reclaimed KHI stream 162 to the KHI reformulation unit 164. The KHI reformulation unit 164 may engage in KHI mixing For example, the KHI reformulation unit 164 may mix the reclaimed KHI stream 162 with one or additional components based on a desired formulation. As such, the exit stream from the KHI reformulation unit 164 may be a reformulated KHI stream 22.

[0071] Along the flow path of the reformulated KHI stream 22 may be sensors 156c. In certain embodiments, the sensors 156c include temperature sensors, pressure sensors, flow rate sensors, and fluid composition sensors, thereby enabling measurements of temperature, pressure, flow rate, and fluid composition of the reformulated KHI stream 22. The sensors 156c may include at least one fluid composition sensor configured to analyze the composition (e.g., percentage or concentration of various components) of the reformulated KHI stream 22. Further, the sensors 156c may be substantially similar in operation to sensors 156a and sensors 156b. If the sensors 156c detects the reformulated KHI stream 22 meets the threshold target composition, then the controller 34 may control the valve 182 to direct a flow of the reformulated KHI stream 22 to the storage tank 168, as described in more detail below. However, if the sensors 156c detects the reformulated KHI stream 22 does not meet the threshold target composition, then the controller 34 may control the valve 182 to direct at least a portion of all of the flow of the reformulated KHI stream 22 along a recirculation flow path 183 back to the KHI reformulation unit 164 to further purify the reformulated KHI stream 22. This process may be repeated until the reformulated KHI stream 22 meets the thresholdIS25.0381-WO-PCT composition targets for the process. Once the reformulated KHI stream 22 meets the threshold composition targets for the process, then the controller 34 may control the valve 182 to direct the reformulated KHI stream 22 to the storage tank 168.

[0072] In certain embodiments, the controller 34 adjusts a position of the valve 182 to direct at least a portion of the reformulated KHI stream 22 along the recirculation flow path 183 until each component of the fluid composition is generally steady within desired thresholds. However, the controller 34 may generally hold and / or continuously vary the position of the valve 182 to maintain at least some recirculation flow of the reformulated KHI stream 22 and at least some flow of the reformulated KHI stream 22 to the storage tank 168. The KHI reclamation and regeneration system 20b may provide similar control for the temperature, pressure, flow rate, and fluid composition.

[0073] The regenerated KHI raw material may be stored in the storage tank 168 for reinjection with a lean MEG stream into the subsea gas wells for hydrate inhibition. The reformulated KHI 22 stream may be removed from the storage tank 168 and directed to the blending unit 30 configured to blend the reformulated KHI stream 22 with the lean MEG stream 28 from the MEG reclamation and regeneration unit 24. The blending unit 30 may be within the MEG reclamation and regeneration unit 24. In some embodiments, however, the blending unit 30 may be a separate onsite unit. A lean MEG and KHI stream 32 may be directed out of the blending unit 30 and directed to various oil and gas applications, including subsea injection. The blending unit 30 may generate a hydrate treatment fluid.. In some embodiments, the hydrate treatment fluid is the lean MEG and KHI stream 32.

[0074] In another embodiment, a method for recovery of the KHI removal solvent begins by processing the bottom product stream 120 that is saturated with at least one KHI polymeric actives and no or minimal MEG and water by directing the feed into a vacuum boiler. The vacuum boiler may vaporize the solvent at a lower temperature to minimize the duty requirements and polymer degradation. The boiler may be equipped with a mechanical means that purifies the solvent vapor. Next, the system may send the purified overhead solvent vapor to a vacuum distillation column to produce a high- purity recycled solvent liquid, and the recycled solvent is then stored in a storage tank not included in the illustrated embodiment for KHI product reformulation.IS25.0381-WO-PCT

[0075] In another embodiment, the reversed solvent extraction phase described above is replaced with a second boiler to regenerate KHI raw from solid material, and the system may send the purified bottom product stream 154 to the second boiler to fully evaporate the solvent and generate KHI-active solids in the bottom. The second boiler may be equipped with a mechanical means that facilitates mixing the dry KHI actives with regeneration solvent feed to produce a raw KHI material. The second boiler may further be equipped with a mechanical means to purify the overhead vapor before being mixed with the steam and sent to the distillation column. Lastly, the regenerated KHI raw is stored in a storage tank not included in the illustrated embodiment for KHI product reformulation.

[0076] The present method provides smooth reclamation of MEG without the polymeric KHI activities in the MEG stream, eliminating the waste streams from the KHI removal process, regenerating the KHI raw material, and reducing the overall OPEX of the KHI-MEG integration for gas hydrate inhibition.

[0077] FIG. 5 is a flow diagram illustrating a process 200 of the extraction process and solvent recovery as described above with reference to FIGS. 1-4. The process 200 may be executed and / or controlled by one or more processor-based systems, such as the controller 34. The process 200 may perform each step using various equipment described above with reference to FIGS. 1-4. In block 202, the process 200 may remove solids from a source stream (e.g., rich MEG with KHI stream) in a pretreatment unit 50 and output a filtered stream (e.g., filtered rich EG with KHI stream) and a waste stream (e.g., solids).

[0078] In block 204, the process 200 may separate the filtered stream (e.g., filtered rich MEG with KHI stream) into an extract stream (e.g., solvent containing a bulk extracted solute such as KHI active material) and a MEG raffinate stream (e.g., rich MEG, substantially free of KHI) via a liquid-liquid extractor 58. Specifically, the liquid-liquid extractor 58 may include extraction columns, mixer-settlers, centrifugal extractors, or any other unit configured to receive two inlet streams and produce two outlet streams. This process is described in more detail above. The solvent may extract other active materials that are present in the filtered stream (i.e., similar actives materials from other flow assurance chemicals like corrosion inhibitors). ExtractedIS25.0381-WO-PCT actives other than the KHI are small. As such, the bulk extracted solute will be the KHI actives.

[0079] In block 206, the process 200 may separate the extract stream (e.g., filtered rich MEG with KHI) into a solvent recycle stream (e.g., solvent containing a bulk extracted solute such as KHI active material) and a concentrated KHI stream via a solvent recovery system 20a. Further, in block 208, the process 200 may separate the MEG raffinate stream (e.g., rich MEG, substantially free of KHI) into a solvent recycle stream (e.g., substantially pure solvent) and a pretreated MEG stream via a solvent recovery system 20a. Blocks 206 and 208 are described in detail in the description for FIG. 3.

[0080] FIG. 6 is a flow diagram illustrating an embodiment of a process 220 of the second portion of the KHI reclamation and regeneration system 20b. This process 220 is described above in more detail in FIG. 4. The process 220 may be executed and / or controlled by one or more processor-based systems, such as the controller 34. The process 220 may perform each step using various equipment described above with reference to FIGS. 1-4, particularly with reference to FIG. 4. In block 222, the process 220 may direct a solvent with KHI to a purification unit to create a purified product. Specifically, the purified product may remove all or substantially all non-KHI actives.

[0081] In block 224, the process 220 may determine if the purified product meets the target composition. The target composition may depend on the desired operation parameters. However, the target composition may be about 0-80% extraction solvent and about 20-40% KHI active material. If the purified product does not meet the target composition, then the process 220 may proceed to block 226. In block 226, the process 220 may direct the purified product through the purification unit again, before the process 220 returns to block 224. The process 220 may repeat blocks 224 and 226 until the composition of the purified product meets or surpasses the target composition. Once the purified product meets or surpasses the target composition in block 224, then the process 220 directs the purified product through the KHI reclamation unit to reclaim KHI from the purified product in block 228.

[0082] Next, in block 230, the process 220 may determine if the reclaimed KHI meets the target composition. The target composition may depend on the desiredIS25.0381-WO-PCT operation parameters. However, the target composition may be about 50-80% KHI original solvent and about 20-50% KHI active material. If the reclaimed KHI does not meet the target composition, then the process 220 may proceed to block 232. In block 232, the process 220 may direct the reclaimed KHI through the KHI reclamation unit again, before the control system returns to block 230. The process 220 may repeat blocks 230 and 232 until the composition of the reclaimed KHI meets or surpasses the target composition. Once the reclaimed KHI meets or surpasses the target composition in block 230, then the process 220 directs the reclaimed KHI through the KHI reformation unit to reform KHI from the reclaimed KHI in block 234.

[0083] Next, in block 236, the process 220 may determine if the reformed KHI meets the target composition. The target composition may depend on the desired operation parameters. If the reformed KHI does not meet the target composition, then the process 220 may proceed to block 238. In block 238, the process 220 may direct the reformed KHI through the KHI reformation unit again, before the control system returns to block 236. The process 220 may repeat blocks 236 and 238 until the composition of the reformed KHI meets or surpasses the target composition. Finally, once the reformed KHI meets or surpasses the target composition in block 236, then the process 220 blends the reformulated KHI with the lean MEG from the MEG reclamation and regeneration unit in block 240.

[0084] Technical effects of the disclosed embodiments provide separation, reclamation, and regeneration of different hydrate inhibitors (e.g., MEG and KHI) in a feed stream (e.g., Rich MEG stream having KHI and other materials), such that the MEG and KHI can be re-used in various applications. In particular, the disclosed embodiments apply liquid-liquid extraction techniques for a bulk separation of the feed stream into a first stream (e.g., MEG stream) and a second stream (e.g., KHI stream). The disclosed embodiments further perform various stages of processing, filtering, separation, and / or distillation to purify or concentrate the MEG in the first stream (e.g., MEG stream) and the KHI in the second stream (e.g., KHI stream). Subsequently, the disclosed embodiments may reformulate the KHI and the MEG for reuse, including blending the KHI and MEG in a new stream for use in various applications.

[0085] The subject matter described in detail above may be defined by one or more clauses, as set forth below.IS25.0381-WO-PCT

[0086] A method including receiving a flowing rich mono ethylene glycol (MEG) stream, directing the rich MEG stream to a pretreatment unit, filtering and removing all suspended solids and other free species not chemically bound to main rich MEG chemicals in the rich MEG stream, to produce a filtered rich MEG stream, directing the filtered rich MEG stream to an extraction unit, contacting the filtered rich MEG stream with an extraction solvent in the extraction unit to produce an extraction stream and a raffinate liquid, directing the raffinate liquid to a purifying unit to produce a recovered pure solvent and a purified rich MEG stream, and directing the purified rich MEG stream to a final unit.

[0087] The method of the preceding clause, wherein the rich MEG stream includes MEG, water, salts, one or more kinetic hydrate inhibitor (KHI) actives, flow assurance chemicals, and other free and dissolved organic and inorganic species.

[0088] The method any preceding clause, wherein the pretreatment unit includes all types of filtration systems such as bag filters, clean-in-place filters, cartridge filters, high-flow filters, membranes, centrifuges, multimedia filters, and all filters that work with or without precoating.

[0089] The method any preceding clause, wherein the extraction unit is a liquidliquid extraction unit.

[0090] The method any preceding clause, wherein the extraction solvent includes any liquid with the required distribution coefficient to extract the KHI actives from the rich MEG stream and the desired chemical and physical properties that enable phase separation with minimum or miscibility in the rich MEG stream.

[0091] The method any preceding clause, wherein the extraction unit facilitates the mass transfer of bulk KHI actives from the rich MEG stream into the extraction solvent to produce the extraction stream.

[0092] The method any preceding clause, wherein the extraction stream is directed to a solvent recovery unit to separate the KHI actives from the extraction stream to produce a pure solvent stream including pure extraction solvents.IS25.0381-WO-PCT

[0093] The method any preceding clause, wherein the raffinate liquid includes a treated rich MEG stream with a reduced concentration of KHI actives and entrained solvent.

[0094] The method any preceding clause, wherein the purifying unit is selected from the group consisting of a distillation column, a stripping column, a liquid membrane, a centrifuge, or any suitable process equipment.

[0095] The method any preceding clause, wherein the final unit includes a MEG reclamation unit or other pretreatment unit.

[0096] A system for purifying a mono ethylene glycol (MEG) stream including a pretreatment unit, an extraction unit, a purifying unit, and a final unit, wherein the system purifies MEG by receiving a flowing rich mono ethylene glycol (MEG) stream, directing the rich MEG stream to a pretreatment unit, filtering and removing all suspended solids and other free species not chemically bound to main rich MEG chemicals in the rich MEG stream, to produce a filtered rich MEG stream, directing the filtered rich MEG stream to an extraction unit, contacting the filtered rich MEG stream with an extraction solvent in the extraction unit to produce an extraction stream and a raffinate liquid, directing the raffinate liquid to a purifying unit to produce a recovered pure solvent and a purified rich MEG stream, and directing the purified rich MEG stream to a final unit.

[0097] A method includes receiving a source stream into a liquid-liquid extractor. The source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The method also includes receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives. The method also includes separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquid-liquid extraction using the extraction solvent, outputting the extract stream including the KHI actives and the extraction solvent, and outputting the raffinate stream including the rich MEG.

[0098] The method of the preceding clause, wherein receiving the source stream includes receiving the source stream from an oil and gas system.IS25.0381-WO-PCT

[0099] The method of any preceding clause, including pretreating the source stream via a pretreatment unit upstream from the liquid-liquid extractor.

[0100] The method of any preceding clause, wherein pretreating includes removing suspended solids from the source stream.

[0101] The method of any preceding clause, wherein the pretreatment unit includes one or more filters, gravity separators, centrifugal separators, or a combination thereof.

[0102] The method of any preceding clause, wherein the liquid-liquid extractor includes an extractor column, a mixer-settler, a centrifugal extractor, or a combination thereof.

[0103] The method of any preceding clause, wherein the extract stream includes about 70-95% of the extraction solvent and about 3-15% of the KHI actives.

[0104] The method of any preceding clause, wherein outputting the extract stream includes supplying the extract stream to a KHI reclamation and regeneration system, and outputting the raffinate stream includes supplying the raffinate stream to a MEG reclamation and regeneration system.

[0105] The method of any preceding clause, including separating the extract stream into a solvent recycle stream and a concentrated KHI stream via a solvent recovery unit, wherein the solvent recycle stream comprises the extraction solvent.

[0106] The method of any preceding clause, wherein the concentrated KHI stream includes about 60-70% of the extraction solvent and about 10-30% of the KHI actives.

[0107] The method of any preceding clause, wherein the solvent recovery unit includes a distillation column, a condenser, a reboiler, and a reflux drum.

[0108] A system includes a liquid-liquid extractor. The liquid-liquid extractor includes a source inlet configured to receive a source stream, wherein the source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The liquid-liquid extractor includes a solvent inlet configured to receive an extraction solvent, wherein the extraction solvent has an affinity for the KHI actives, a liquid-liquid extraction section configured to separate the source stream into an extractIS25.0381-WO-PCT stream and a raffinate stream via a liquid-liquid extraction using the extraction solvent, an extract outlet configured to output the extract stream including the KHI actives and the extraction solvent, and a raffinate outlet configured to output the raffinate stream including the rich MEG.

[0109] The system of the preceding clause, wherein the pretreatment unit includes one or more filters, gravity separators, centrifugal separators, or a combination thereof.

[0110] The system of any preceding clause, wherein the liquid-liquid extractor includes an extractor column, a mixer-settler, a centrifugal extractor, or a combination thereof.

[0111] The system of any preceding clause, including a solvent recovery unit configured to separate the extract stream into a solvent recycle stream and a concentrated KHI stream, wherein the solvent recycle stream includes the extraction solvent.

[0112] The system of any preceding clause, wherein the extract stream includes about 70-95% of the extraction solvent and about 3-15% of the KHI actives, and the concentrated KHI stream includes about 60-70% of the extraction solvent and about 10-30% of the KHI actives.

[0113] A system including a controller having a processor, a memory, and instructions stored on the memory and executable by the processor to perform operations including receiving a source stream into a liquid-liquid extractor. The source stream includes a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives. The processor may also perform operations including receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives, separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquid-liquid extraction using the extraction solvent, outputting the extract stream including the KHI actives and the extraction solvent, and outputting the raffinate stream including the rich MEG.

[0114] The system of the preceding clause, wherein the instructions of the controller are configured to perform operations including pretreating the source stream via a pretreatment unit upstream from the liquid-liquid extractor, wherein pretreatingIS25.0381-WO-PCT comprises removing suspended solids from the source and separating the extract stream into a solvent recycle stream and a concentrated KHI stream via a solvent recovery unit, wherein the solvent recycle stream includes the extraction solvent.

[0115] The system of any preceding clause, wherein the extract stream includes about 70-95% of the extraction solvent and about 3-15% of the KHI actives, and the concentrated KHI stream includes about 60-70% of the extraction solvent and about 10-30% of the KHI actives.

[0116] While only certain features have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.

[0117] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for (perform)ing (a function)...” or “step for (perform)ing (a function)...”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

Claims

IS25.0381-WO-PCTCLAIMS1. A method, comprising: receiving a source stream into a liquid-liquid extractor, wherein the source stream comprises a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives; receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives; separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquid-liquid extraction using the extraction solvent; outputting the extract stream comprising the KHI actives and the extraction solvent; and outputting the raffinate stream comprising the rich MEG.

2. The method of claim 1, wherein receiving the source stream comprises receiving the source stream from an oil and gas system.

3. The method of claim 1, comprising pretreating the source stream via a pretreatment unit upstream from the liquid-liquid extractor.

4. The method of claim 3, wherein pretreating comprises removing suspended solids from the source stream.

5. The method of claim 4, wherein the pretreatment unit comprises one or more filters, gravity separators, centrifugal separators, or a combination thereof.

6. The method of claim 1, wherein the liquid-liquid extractor comprises an extractor column, a mixer-settler, a centrifugal extractor, or a combination thereof.

7. The method of claim 1, wherein the extract stream comprises about 70-95% of the extraction solvent and about 3-15% of the KHI actives.

8. The method of claim 1, wherein outputting the extract stream comprises supplying the extract stream to a KHI reclamation and regeneration system, andIS25.0381-WO-PCT outputting the raffinate stream comprises supplying the raffinate stream to a MEG reclamation and regeneration system.

9. The method of claim 1, comprising: separating the extract stream into a solvent recycle stream and a concentrated KHI stream via a solvent recovery unit, wherein the solvent recycle stream comprises the extraction solvent.

10. The method of claim 9, wherein the concentrated KHI stream comprises about 60-70% of the extraction solvent and about 10-30% of the KHI actives.

11. The method of claim 9, wherein the solvent recovery unit comprises a distillation column, a condenser, a reboiler, and a reflux drum.

12. A system, comprising: a liquid-liquid extractor, comprising: a source inlet configured to receive a source stream, wherein the source stream comprises a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives; a solvent inlet configured to receive an extraction solvent, wherein the extraction solvent has an affinity for the KHI actives; a liquid-liquid extraction section configured to separate the source stream into an extract stream and a raffinate stream via a liquid-liquid extraction using the extraction solvent; an extract outlet configured to output the extract stream comprising the KHI actives and the extraction solvent; and a raffinate outlet configured to output the raffinate stream comprising the rich MEG.

13. The system of claim 12, comprising a pretreatment unit upstream from the liquid-liquid extractor, wherein the pretreatment unit is configured to pretreat the source stream at least by removing suspended solids from the source stream.IS25.0381-WO-PCT14. The system of claim 13, wherein the pretreatment unit comprises one or more filters, gravity separators, centrifugal separators, or a combination thereof.

15. The system of claim 12, wherein the liquid-liquid extractor comprises an extractor column, a mixer-settler, a centrifugal extractor, or a combination thereof.

16. The system of claim 12, comprising a solvent recovery unit configured to separate the extract stream into a solvent recycle stream and a concentrated KHI stream, wherein the solvent recycle stream comprises the extraction solvent.

17. The system of claim 16, wherein the extract stream comprises about 70-95% of the extraction solvent and about 3-15% of the KHI actives, and the concentrated KHI stream comprises about 60-70% of the extraction solvent and about 10-30% of the KHI actives.

18. A system, comprising: a controller having a processor, a memory, and instructions stored on the memory and executable by the processor to perform operations comprising: receiving a source stream into a liquid-liquid extractor, wherein the source stream comprises a rich mono ethylene glycol (MEG) and a kinetic hydrate inhibitor (KHI) actives; receiving an extraction solvent into the liquid-liquid extractor, wherein the extraction solvent has an affinity for the KHI actives; separating the source stream into an extract stream and a raffinate stream in the liquid-liquid extractor via a liquid-liquid extraction using the extraction solvent; outputting the extract stream comprising the KHI actives and the extraction solvent; and outputting the raffinate stream comprising the rich MEG.

19. The system of claim 18, wherein the instructions of the controller are configured to perform operations comprising:IS25.0381-WO-PCT pretreating the source stream via a pretreatment unit upstream from the liquidliquid extractor, wherein pretreating comprises removing suspended solids from the source stream; and separating the extract stream into a solvent recycle stream and a concentrated KHI stream via a solvent recovery unit, wherein the solvent recycle stream comprises the extraction solvent.

20. The system of claim 19, wherein the extract stream comprises about 70-95% of the extraction solvent and about 3-15% of the KHI actives, and the concentrated KHI stream comprises about 60-70% of the extraction solvent and about 10-30% of the KHI actives.

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