Two-step synthesis of gamma valerolactone

Abstract

A method of forming gamma valerolactone (GVL) includes contacting trans 3-pentenenitrile (3PN) with water in a first reactor at temperatures of 200-300°C under pressure to form a first product mixture containing pentenoic acid and ammonia. The method includes separating substantially all ammonia from the first product mixture to form an intermediate mixture. The method also includes contacting the intermediate mixture with a heterogeneous catalyst in a second reactor to form a second product mixture comprising GVL.

Description

Docket No. INV-24032-WO-PCTTWO-STEP SYNTHESIS OF GAMMA VALEROLACTONECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 750,298 filed Jan. 28, 2025, the disclosure of which is incorporated herein in its entirety by reference.BACKGROUND

[0002] Cyclic esters, such as lactones, are useful chemical intermediates in a variety of applications. For example, gamma valerolactone (GVL), can be used as a biofuel, in the manufacture of certain polymeric membranes, and in some cases even as a fragrance.SUMMARY

[0003] Various aspects of the present disclosure provide a method of forming gamma valerolactone (GVL). The method includes contacting within a first reactor a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture including pentenoic acid and ammonia is formed. The method includes separating substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed. The method also includes contacting within a second reactor the intermediate mixture with a heterogeneous catalyst whereby a second product mixture including GVL is formed.

[0004] Various aspects of the present disclosure provide a system for forming gamma valerolactone (GVL). The system includes a first reactor configured to combine a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture including pentenoic acid and ammonia is formed. The system includes a gas flushing apparatus configured to separate substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed. The system also includes a second reactor configured to combine the intermediate mixture with a heterogeneous catalyst, whereby a second product mixture including GVL is formed.

[0005] Various aspects of the present disclosure provide a system for forming gamma valerolactone (GVL). The system includes means for contacting within a first reactor a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixtureDocket No. INV-24032-WO-PCT including pentenoic acid and ammonia is formed. The system includes means for separating substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed. The system also includes means for contacting within a second reactor the intermediate mixture with a heterogeneous catalyst whereby a second product mixture including GVL is formed.

[0006] The present disclosure describes two-step methods and systems for producing a gamma lactone, such as gamma valerolactone (GVL). The first step can involve mixing two chemicals, 3 -pentenenitrile (3PN) and water, in a first reactor at relatively high temperature (e.g., between about 200-300°C) and pressure (e.g., between about 100-2000 psi). Such a reaction can be performed in the reactor without needing a chemical catalyst and can produce a product containing pentenoic acid and additionally producing ammonia as a byproduct. Substantially all of the ammonia that was produced in the first step can be removed, such as via sparging of an inert gas in the first reactor. For example, over 95 weight percentage (wt%) of the ammonia can be removed via the sparging. Such a sparging step can help mitigate or avoid problems in certain, other manufacturing processes where the reaction is hindered due to excess ammonia.

[0007] The second step can involve the remaining mixture, substantially absent of the ammonia, entering a second reactor containing a catalyst and wherein the product, GVL, is formed. The second reactor can operate at relatively lower temperatures such as within a range of about 100-150°C. Various catalyst types include solid acid catalysts and ion exchange resins. In an aspect, additional purification is performed following the second step to purify the final product to greater than 85 wt% GVL.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document.

[0009] FIG. 1 is a schematic diagram of an example of a system for forming gamma valerolactone (GVL), in accordance with various aspects of the present disclosure.

[0010] FIG. 2 is a flowchart illustrating a method for forming GVL, in accordance with various aspects of the present disclosure.Docket No. INV-24032-WO-PCT DETAILED DESCRIPTION

[0011] Reference will now be made in detail to certain aspects of the disclosed subject matter. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0012] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0013] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0014] In the methods described herein, the acts can be carried out in a specific order as recited herein. Alternatively, in any aspect(s) disclosed herein, specific acts may be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately or the plain meaning of the claims would require it. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0015] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.Docket No. INV-24032-WO-PCT

[0016] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. The term “substantially free of’ as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that about 0 wt% to about 5 wt% of the composition is the material, or about 0 wt% to about 1 wt%, or about 5 wt% or less, or less than, equal to, or greater than about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt% or less, or about 0 wt%.

[0017] The present disclosure describes in various aspects a method for forming GVL using 3 -pentenenitrile (3PN) as the starting feed material. The method can involve a lower product carbon footprint for GVL, such as compared to certain bio-derived processes involving hydrogenation. An important intermediate in nylon 66 manufacture, hexamethylenediamine (HMD) can be industrially produced by hydrogenating a six-carbon linear dinitrile, commonly known as adiponitrile (ADN). In an example, the 3PN stream can be collected as a byproduct of an adiponitrile (ADN) manufacturing process, which can help reduce waste and conserve resources. For example, adiponitrile can be synthesized from a double hydrocyanation reaction between butadiene and a cyanide source. This process chemistry can generate a mixture of various mono-nitriles, including 3 -pentene nitrile (3PN) and 2-pentenenitrile (2PN), such as during an initial hydrocyanation step.

[0018] Conventional approaches to producing GVL from pentenenitriles typically employ a single-step process using acid catalysts. Such processes present challenges due to ammonia generation during nitrile hydrolysis. For example, mineral acids are used as homogeneous catalysts, the generated ammonia forms ammonium salts with the acidic medium which significantly increases catalyst consumption of the reaction. While catalyst regeneration is possible through decomposing ammonia from the salts, this process can be undesirably complex, energy-intensive, and costly. Similarly, when using solid acid catalysts in heterogeneous systems, the generated ammonia is adsorbed onto acidic sites, leading to catalyst poisoning and deactivation. Though catalyst regeneration can be implemented to desorb ammonia and reactivate the catalyst, this can add undesired complexity to reactor design and operation.

[0019] The present inventors have recognized the benefits of an improved method and system for producing GVL via a two-step process that effectively addresses the ammonia-related challenges.Docket No. INV-24032-WO-PCT

[0020] In the first step, 3PN is contacted with water in a first reactor at temperatures ranging from 200°C to 300°C at elevated pressure, typically between 100 to 2000 psig. This reaction produces a first product mixture containing pentenoic acid and ammonia. This step can be conducted without a need for acid catalyst, thereby avoiding ammonia-related catalyst deactivation issues.

[0021] The process then incorporates an ammonia separation step whereby substantially all ammonia (greater than 95 weight percentage) is removed from the first product mixture to form an intermediate mixture. This separation can be achieved through various means, including gas sparging. In the second step, the substantially ammonia-free intermediate mixture is contacted with a heterogeneous catalyst in a second reactor operated at temperatures between 100°C to 150°C to produce GVL. The heterogeneous catalyst may include solid acid catalysts, metallic catalysts, or ion exchange resins. Specific examples include styrene-divinylbenzene copolymers and tetrafluoroethylene with perfluorinated vinyl ether. The process can be operated continuously and includes product purification capabilities to achieve GVL purity greater than 85 weight percentage. The system may incorporate various process integration features, including heat exchangers, separation columns, and recycling streams for improved efficiency. Such a two-step approach provides several advantages over certain single-step processes to GVL production, such as mitigation of ammonia-related catalyst deactivation, reduced catalyst consumption, improved process stability, enhanced product yield and purity, and efficient reactant utilization through recycling capabilities. Such a process can be particularly suitable for industrial-scale production, as it can utilize 3PN feed streams obtained directly from adiponitrile manufacturing facilities, typically containing 95 wt% 3PN and 5 wt% 2PN.

[0022] In an example, trans-3 -pentenenitrile can be hydrolyzed into 3 -pentenoic acid and 3-pentenamide in “STEP 1”. Some of these step 1 products then undergo ring-closing (or, lactonization) in “STEP 2”, such as to form gamma-valerolactone. The reaction scheme is shown below:<

[0023] FIG. 1 is a schematic diagram of an example of a system 100 for forming gamma valerolactone (GVL) In FIG. 1, stream 101 is a combination of two independent streams — water and 3PN. The 3PN stream can have a 3PN concentration greater than about 85 weight percentage (wt%) with the balance being 2PN. Stream 101 can enter the fluid circuit at aDocket No. INV-24032-WO-PCT temperature close to the ambient temperature and at a pressure ranging from about 15 pounds per square inch absolute (psia) to about 2000 psia, such as ranging from about 500 psia to about 1000 psia.

[0024] Stream 101 can be mixed with two recycle streams, such as stream 111 and 112. Stream 111 can include a water-rich (e.g., heavier) phase and stream 112 can include a 3PN rich (e.g., organic) stream. The resultant mixed feed stream 102 can be a biphasic (e.g., two-liquid phases) mixture. Stream 102 can include a water-to-3PN molar ratio within the range of about 1:1 to about 50:1. For example, stream 102 can include a water-to-3PN molar ratio of about 1 : 1 to about 30:1.

[0025] In an example, stream 102 can be preheated by heat-exchange in a feed preheater 110. Depending on the heat input, the resulting hot feed stream 103 can be a vapor liquid or a vapor-liquid-liquid mixture. The feed preheater 110 can be heat-integrated with a reactor effluent cooler 130 or can be an independent heat exchanging device. As depicted in FIG. 1, a dotted heat exchange stream HX1 represents an arrangement when the feed preheater 110 and the reactor effluent cooler 130 are heat integrated together meaning they are the same unit. In this arrangement, the hot reactor effluent stream 104 serves as a heating medium to preheat the feed stream 102.

[0026] The preheated stream 103 can flow into a reactor 120. The reactor 120 can include an initial vaporizer and a preheater section configured for vaporizing the stream into a gas phase and preheating the stream to the reactor temperature. The reactor operating temperature can be within the range of about 100°C to about 400°C. The reactor may be operated without a catalyst or a catalyst packed bed and may be operated with a downward flow of the reactants in the bed. The residence time of the reactants may range from about 30 sec to about 10 hours, such as less than about 6 hours, less than about 5 hours, or less than about 4 hours.

[0027] The reactor effluent stream 104 exiting the reactor 120 can be cooled and at least partially condensed into a cooled reactor effluent mixture stream 105 in the reactor effluent cooler 130 that can be directly heat integrated with the mixed feed stream 102. For example, the heat content of the reactor effluent stream 104 can be heat-exchanged to preheat the mixed feed stream 102.

[0028] The cooled reactor effluent stream 105 can be fed at or near a top section of a first column 140 to remove any ammonia generated from the reaction. In an example, the first column 140 can be equipped with an overhead condenser and a bottom reboiler unit. The first column 140 can have at least 15, such as at least 8, at least 10, or at least 12 theoretical stages and operated at a specified pressure, the specified pressure selected such that the overheadDocket No. INV-24032-WO-PCT condenser temperature is approximately in the range of 4°C to 10°C. In an example, a pressure in the overhead condenser pressure can be controlled at or near about 22 psia. The vapor stream obtained from the overhead condenser can have a concentrated ammonia stream 107. The first column bottom stream 106 can contain less than 100 parts per million (ppm) by weight of ammonia.

[0029] The first column bottom stream 106 can be fed toward a second column 150. The stream 106 can be further distilled and separated into a two-phase liquid mixture 109 at the top and the second column bottom stream 108 rich in the desired reaction product, such as including primarily a lactone along with other near-boiling side-products. The second column 150 can have at least 15, such as at least 20, at least 25, or at least 30 theoretical stages. The second column overhead condenser can be operated at or near atmospheric pressure and the stream 106 can be fed toward the top of the second column 150. Any excess water, 3PN, or other generated low-boiling byproducts from the reactor 120 can be concentrated in the second column overhead stream 109. The overhead condenser of the second column 150 can be, e.g., a partial or a total condenser. As depicted in FIG. 1, stream 109 represents the combined flow of both the vapor and liquid distillate exiting the overhead condenser.

[0030] The second column overhead stream 109 can be separated into two phases in a phase separator 155. The phase separator 155 can provide adequate residence time for the stream 109 to undergo phase separation at the operating conditions. For example, the phase separator 155 can be a gravity settler, a decanter, or combination of settler and a centrifuge. The phase separator 155 can split the stream 109 into a water-rich, heavier stream 111 and an organic-rich, lighter stream 112. Any non-condensable components can also be separated in the phase separator 155 and discharged via an offgas stream 113. Up to about 20%, such as up to about 10% (by weight) of the aqueous phase 111 can be purged such as to avoid buildup of any undesired contaminants in the aqueous stream 111. Similarly, an organic stream 112 purge can be included such as to minimize buildup of any organic contaminants in the organic stream 112. Both, the organic stream 112 and the aqueous stream 111 can be recycled back to the reactor feed mixer Ml. The mixer Ml can be an intermediate feed collection tank, a storage vessel, or a pipeline flow mixing device during the continuous operation.

[0031] The second column 150 bottom stream 108 can be fed at or near a mid-section (e.g., at or near a vertical midline) of a third column 175. The second column bottom stream 108 can be enriched with a desired reaction product along with some high boiling fraction and certain hydrolysis reaction intermediates (e.g. 3 -pentenoic acid or penteneamides). In the third column 175, the stream 108 can be separated into a reaction intermediates stream 121,Docket No. INV-24032-WO-PCT while the desired lactone product together with the penteneamides can be concentrated at the column bottom as the crude product stream 119. The third column 175 can have at least 20, such as at least 25, at least 30, or at least 35 theoretical stages and can be operated under relatively low pressure (e.g., within a range of about 1 psia to about 15 psia) and at the temperature within the range of about 120°C to about 220°C.

[0032] The precursors to lactone present in stream 121 can be further isomerized such as to afford additional lactone product. Non-limiting examples of such precursors include 2-pentenoic acid, 3 -penteneoic acid, 2-pentenamide and 3-pentenamide. The intermediates stream 121 can undergo further chemical transformation in an isomerization reactor 165. A fresh supply of water stream 114 can be provided to the reactor 165, such as to help facilitate isomerization reaction. The water-to-3 -pentenoic acid molar ratio of about 0.1 to about 5 can be provided to promote the isomerization reaction in 165. The reactor 165 can be operated at temperatures of at or below about 290°C. The reactor can be a packed bed reactor operated with a residence time ranging from about 30 seconds to about 100 minutes. The isomerization reaction product stream 117 from the reactor 165 can either be separately refined or can be routed to the second column 150 at or near the column bottom, as shown in FIG. 1.

[0033] In an example, the crude lactone product bottom stream 119 exiting the third column 175 can be fed near the top-section of a fourth column 180 for product purification. The fourth column 180 can provide a plurality of separation stages to purify the desired product in the overhead stream 122. The fourth column bottom stream 123 can consist primarily of the high-boiling components along with high boiling reaction intermediate amides that can be either routed partially to the mixer Ml or purged for proper disposal. The fourth column 180 can include at least 20 theoretical stages and can be operated at a relatively low pressure (e.g., about 1-15 psia) and in the temperature range of about 120 °C to 280 °C.EXAMPLES

[0034] Various aspects of the present disclosure can be better understood by reference to the following Examples, which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.

[0035] Materials Used in the Examples. The 3-PN feed was obtained from an industrial nitrile manufacturing facility. The 3-PN feed composition was 95 wt% 3PN and 5 wt% 2PN. An example of 3-PN feed may be an intermediate product stream obtained from adiponitrile manufacture process. Water used in the process may meet the boiler-feed water feedDocket No. INV-24032-WO-PCT specifications. The catalyst used in the isomerization process may be a supported heterogeneous solid-acid catalyst.Example 1.

[0036] A process carried out on the system 100, as depicted in FIG. 1, is employed in this example. Tables 1, Table 2, and Table 3 provide respective stream summaries, each corresponding to the FIG. 1 method. The major streams are represented in FIG. 1 and auxiliary equipment such as pumps, purge points, instruments, fittings, etc. are not shown in FIG. 1.

[0037] Table 1.>Docket No. INV-24032-WO-PCT

[0038] Table 2.>Docket No. INV-24032-WO-PCT

[0039] Table 3.>

[0040] About 100 kg / hr water-3PN feed stream 101 is mixed with two recycle streams 111 and 112. The total mixed feed stream 102 includes about 60:40 (wt:wt) 3PN:water. The mixed feed stream 102 is preheated to about 244 C and the liquid-liquid feed mixture 103 is fed to the reactor 120. The conditions in the reactor 120 are maintained such that the 3PN undergoes hydrolysis with water to acids followed by lactonization (or ring closure) to form the desired product gamma-valerolactone (GVL). The hydrolysis reaction evolves ammonia originating from the nitrile group in the 3PN.

[0041] The reactor effluent stream 104 is cooled from about 290 C to about 130 C in the effluent cooler 130. The cooled effluent stream 105 is fed to the first column 140. The operating conditions in the first column 140 are maintained such that an overhead gaseous ammonia-rich stream 107 is obtained from the first column 140. The first column bottom stream 106 is devoid of any ammonia species and exits the column.

[0042] The ammonia-lean stream 106 is fed to the second column 150, wherein, the desired lactone product and the near-boiling intermediates and heavy products are furtherDocket No. INV-24032-WO-PCT concentrated in the bottom stream 108 while recovering the excess water and 3PN in the second column overhead stream 109. An adequate residence time is allowed in the phase separator 155 and the conditions are maintained such that for the overhead stream 109 to phase separate into a water-rich stream 111 and an organic-rich stream 112. The concentration of impurities in these two streams is maintained by taking a small purge of each out of the process. The two streams contain useful reactants, mainly 3PN and water, and are recycled to the process and upstream of the reactor 120. Stream 111 contains the excess water and stream 112 contains the unreacted 3PN, both of which are useful in reactor 120.

[0043] The second column 150 bottom stream 108 undergoes further refinement in the third column 175, wherein the crude product stream 119 is obtained from the column. The reaction intermediates, including 3 -pentenoic acid, concentrate in the overhead stream 121.

[0044] The intermediates stream 121, obtained as column 175 overhead, is fed to the second reactor 165 along with the water stream 114. The combined feed stream 115 may be preheated in preheater 160 to its desired temperature and fed to the reactor 165 as the feed stream 116. The water-to-3 -pentenoic acid molar ratio of between about 0.1-to-l to about 10-to-l may be used to carry out the additional isomerization reaction in reactor 165. The reaction converts 3-pentenoic acid and other precursors to lactone. The reactor 165 effluent stream 117 is cooled in heat exchanger 170, and the cooled stream 118 is routed to the second column 150 for further purification. The preheater 160 and cooler 170 may be integrated for effective heat exchange.

[0045] The fourth column 180 is operated to purify the desired lactone product as the overhead stream 122. The high-boiling components and impurities accumulate at the fourth column 180 bottom and can be routed for purging. Alternatively, stream 123 can be partially recycled back to mixer Ml depending on its composition. For example, stream 123 can be further purified to obtain a purer stream of the intermediates, such as, 2- and 3-pentenamides. The purified stream 123 may be recycled back to mixer Ml, wherein the intermediates are further utilized for the conversion in reactor 120. The disclosed process of Example 1 is effective in producing a high-purity gamma-valerolactone starting from the 3PN feed. The refined product stream 122 of at least 99.9% purity is suitable for many industrial applications. The recycling of the excess water and unreacted 3PN provides a lower carbon footprint via reduced organic waste and water conservation.Example 2, Uncatalyzed hydrolysis of 3PN.

[0046] 3 -Pentenenitrile (3PN) (85 g, 1.05 mol) was added in water (195 g, 10.82 mol) in an autoclave reactor. The mixture was heated at 260 °C and 1200 psig under mechanical stirringDocket No. INV-24032-WO-PCT for 6 h. The experiment was run under continuous N2 sparge to remove ammonia produced in the process. Samples were collected every hour for evaluation using a dip tube. Gas chromatography (GC) was run on the samples. GC trace showed gamma-valerolactone (GVL) pentenoic acids and pentenamides as the major components of the product mixture. The yield of GVL was approximately 5-10%. Yield of pentenoic acids was approximately 20-30%

[0047] The product mixture from the uncatalyzed hydrolysis step was taken in a vial and Amberlyst 36 resin (1g) was added. The vial was closed and heated in a heat block at 120 °C for 16 h. After cooling, the product mixture was analyzed by GC. As estimated from the GC trace, the yield of GVL increased to 30-40% compared to the original product mixture.Example 3, Catalyzed hydrolysis of 3PN.

[0048] 3 -Pentenenitrile (85 g, 1.05 mol) was added in water (195 g, 10.82 mol) followed by 85% phosphoric acid (5g, 43.4 mmol) in an autoclave reactor. The mixture was heated at 260 °C and 1200 psi under mechanical stirring for 6 h. The experiment was run under continuous N2 sparge to remove ammonia produced in the process. Samples were collected every hour for evaluation using a dip tube. Gas chromatography was run on the samples. GC trace showed gamma-valerolactone (GVL) pentenoic acids and pentenamides as the major components of the product mixture. The reaction was faster in presence of catalyst compared to the uncatalyzed reaction of Example 2. The yield of GVL was approximately 5-10%. Yield of pentenoic acids was approximately 20-30%

[0049] FIG. 2 is a flowchart showing process for forming gamma valerolactone (GVL). A process 200 for producing gamma valerolactone (GVL) can include several processing steps performed in sequence, such as performed on the system 100 of FIG. 1.

[0050] At 202, a trans-3 -pentenenitrile (3PN) stream is contacted with the water stream within a first reactor. The reaction conditions in the first reactor can include controlling a temperature within a range of 200°C to 300°C and applying pressure within a range of 100 to 2000 pounds per square inch absolute (psia). Under these conditions, a first product mixture is formed containing pentenoic acid and ammonia as reaction products.

[0051] At 204, substantially all ammonia is separated from the first product mixture, specifically removing greater than 95 weight percentage of the ammonia that was produced during the first reaction step. This separation produces an intermediate mixture substantially free of ammonia.

[0052] At 206, the intermediate mixture flows to a second reactor containing a heterogeneous catalyst. The second reactor operates at temperatures between 100°C toDocket No. INV-24032-WO-PCT 150°C. Within this reactor, the intermediate mixture contacts the heterogeneous catalyst, which may include solid acid catalysts, metallic catalysts, ion exchange resins, or combinations thereof. This catalytic reaction produces a second product mixture containing the desired GVL product.

[0053] The process 200 can optionally include additional purification steps to achieve GVL purity levels exceeding 85 weight percentage. The entire process can be operated in a continuous manner, with various streams being recycled back into the process for improved efficiency.

[0054] In various aspects, the reaction solution includes a heterogeneous catalyst. The heterogeneous catalyst can be a solid acid catalyst. The solid acid catalyst is a solid in the reaction solution. The solid acid catalyst can be any suitable solid acid catalyst, such as a zeolite (e.g., ZSM-5), an ion-exchange resin (e.g., Amberlyst), tungstated zirconia, a silicoaluminophosphate (e.g., SAPO 34), a perfluorosulfonic acid polymer (e.g., Nafion resin), a solid acid, solid phosphoric acid, sulfonated zirconia, montmorillonite, a sulfated metal oxide, a heteropolyacid, a solid superacid, a mesoporous material, or a combination thereof. The solid acid catalyst can include an ion-exchange resin, a zeolite, tungstated zirconia, or a combination thereof. Zeolites can include crystalline aluminosilicates that can have a three-dimensional network of channels and cavities that act as catalysts due to their acidic nature. Sulfated metal oxide catalysts can include sulfated zirconia (ZrCh), sulfated alumina (AI2O3), and sulfated tin oxide (SnCh) and can exhibit strong acidity. Heteropolyacids can include solid acids based on polyoxometalates, which are metal-oxygen clusters. Examples of heteropolyacids include phosphotungstic acid (H3PW12O40) and phosphomolybdic acid (H3PM012O40). Solid superacids are solid materials of exceptionally high acidity surpassing that of typical liquid acids, with examples including fluorosulfonic acid (FSO3H) and trifluoromethanesulfonic acid (CF3SO3H). Mesoporous materials, such as mesoporous aluminosilicates, can exhibit acidic properties and can act as solid acid catalysts. The solid acid catalyst can form any suitable proportion of the reaction solution, such as 0.001 wt% to 90 wt% of the reaction solution, or 30 wt% to 80 wt%, or less than or equal to 90 wt% and greater than or equal to 0.001 wt% and less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 89 wt%. The solid acid catalyst can be 0.001 wt% to 95 wt% of a total amount of the solid acid catalyst and the substituted or unsubstituted cyano(C4-Cio)alkene or the hydrolysis product thereof in the reaction solution, or 60 wt% to 90 wt%, or less than or equal to 95 wt% and greater than or equal to 0.001 wt% and less than, equal to, or greater than 0.005 wt%, 0.01,Docket No. INV-24032-WO-PCT 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, or 94 wt%.

[0055] In various aspects, the reaction solution can be free of added solvents. In other aspects, the reaction solution includes one or more added solvents. The solvent can be any suitable solvent, such as water, an organic solvent, an alcohol, a non-halogenated solvent, a polar solvent, an oxygenated solvent, or a combination thereof. The solvent can be commercially and readily available. The solvent can have a normal boiling point not more than 200 °C, 190 °C, 180 °C, or not more than 175 °C, such as for ease of separation, recovery, purification from the reaction effluent, recycle for re-use in the method, or a combination thereof. The solvent can be water. The solvent can form any suitable proportion of the reaction solution, such as 0.001 wt% to 90 wt% of the reaction solution, or 30 wt% to 60 wt%, or less than or equal to 90 wt% and greater than or equal to 0.001 wt% and less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 89 wt%.

[0056] The formation of the reaction solution can be performed at any suitable temperature, such as a temperature of -20 °C to 400 °C, or -10 °C to 30 °C, or less than or equal to 400 °C and greater than or equal to -20 °C and less than, equal to, or greater than -15 °C, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 150, 200, 250, 300, or 350 °C. The method can include forming the reaction solution at about room temperature (e.g., 20 °C to 30 °C). In various aspects, the method includes forming the reaction solution and maintaining the reaction solution during the formation thereof at a temperature of about 0 °C, or in a range of -10 °C to about 10 °C, or less than or equal to 10 °C and greater than or equal to -10 °C and less than, equal to, or greater than -9 °C, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 °C. The forming of the reaction solution can include cooling the reaction solution to maintain or decrease a temperature thereof.

[0057] Allowing the reaction solution to react can include heating the reaction solution to a reaction temperature for a heating duration. For example, the heating can include heating to a reaction temperature of 20 °C to 400 °C, 20 °C to 150 °C, or 40 °C to 90 °C, or less than or equal to 400 °C and greater than or equal to 20 °C and less than, equal to, or greater than 25 °C, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 175, 180, 190, 200, 250, 300, or 350 °C. The reaction temperature can be maintained for a heating duration of 10 minutes to 24 h, or 30 minutes to 5 h, or less than or equal to 24 h and greater than or equal to 30 minutes and less than, equal to, or greaterDocket No. INV-24032-WO-PCT than 1 h, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, or 22 h. The reaction of the reaction solution can be performed at about ambient pressure.

[0058] An advantage of the present disclosure is formation of GVL in high yields, such as a yield of 50% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 50% and less than, equal to, or greater than 55%, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%. The method can include a percent conversion of the 3PN of 80% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 80% and less than, equal to, or greater than 82%, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%.

[0059] The GVL formed by the method can be substantially free of byproduct, such as ammonia. For example, byproducts can be 0 wt% to 10 wt% of the produced substituted or unsubstituted gamma-lactone, or 0 wt% to 2 wt%, or less than or equal to 10 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.001 wt%, 0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 3, 4, 5, 6, 7, 8, or 9 wt%.

[0060] The method can include heating the reaction solution including the heterogeneous catalyst to a reaction temperature of 20 °C to 400 °C, 20 °C to 150 °C, or 40 °C to 90 °C, or less than or equal to 400 °C and greater than or equal to 20 °C and less than, equal to, or greater than 25 °C, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 175, 180, 190, 200, 250, 300, or 350 °C for a heating duration of 10 minutes to 24 h, or 30 minutes to 5 h, or less than or equal to 24 h and greater than or equal to 30 minutes and less than, equal to, or greater than 1 h, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, or 22 h. The method can include forming the GVL from the 3PN and the heterogeneous catalyst at a yield of 80% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 80% and less than, equal to, or greater than 82%, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%. The method can include forming the GVL from the 3PN and the heterogeneous catalyst at a percent conversion of the substituted or unsubstituted 3PN of 80% to 100%, or 95% to 100%, or less than or equal to 100% and greater than or equal to 80% and less than, equal to, or greater than 82%, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98.5, 99, 99.5, 99.9, or 99.99%. The formed GVL can be substantially free of byproducts; for example, byproducts can be 0 wt% to 10 wt% of the produced GVL, or 0 wt% to 2 wt%, or less than or equal to 10 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.001 wt%, 0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 3, 4, 5, 6, 7, 8, or 9 wt%.Docket No. INV-24032-WO-PCT

[0061] The method can include allowing the reaction solution to react to form the GVL in any suitable type of reactor. For example, the reactor can be a batch reactor. In various aspects, the reactor is a continuous reactor.

[0062] In various aspects, the method can be of great industrial importance. The method can make use of the 3PN-containing organic feedstock that is commercially produced in high yields and purity from a large-scale 1,3-butadiene hydrocyanation process. The butadiene double hydrocyanation to dinitrile is a critical chemical route toward making one of the required nylon monomers, specifically Ce diamine or HMD. The hydrocyanation process is a matured and well-optimized process in the world of nylon intermediates manufacture. Therefore, the scale and availability of the unsaturated nitrile favors the viability and industrial utility of the disclosed process. The unsaturated nitrile feedstock, such as 2PN, 3PN, 2-methyl-3 -butenenitrile, or di cyanobutene, will always be available in abundance.

[0063] In various aspects, the mixed feed stream is advantageously free of chemical components such as furfural, levulinic acid, or its alkyl esters (e.g., methyl, ethyl, or isopropyl esters of levulinic acid), furfuryl alcohol, 4-hydroxyvaleric acid, or a combination thereof, which can have a concentration in the reaction solution of 0 wt%, 0 wt% to 0.1 wt%, 0 wt% to 0.001 wt%, < 1 wt.%, < 0.5 wt.%, < 0.1 wt.%, < 100 ppmw, or < 50 ppmw.

[0064] In various aspects, the method of the present disclosure produces substantially low or no impurities or undesired side products. In various aspects, one or more streams of the present disclosure can have a low or zero concentration of certain chemical components, such as, alpha-angelica lactone, furfural -propyl ether, 2-methyl-tetrahydrofuran, 2-butanol, 2-pentanol, 1,4-pentanediol, heavy acid, furfuryl alcohol resin, furfural, levulinic acid or its alkyl (e.g.: methyl, ethyl or iso-propyl) esters, furfuryl alcohol or 4-hydroxyvaleric acid. In various aspects, these chemical components can be present in the reacted reaction solution at concentrations selected from 0 wt%, 0 wt% to 0.1 wt%, 0 wt% to 0.001 wt%, < 1 wt.%, < 0.5 wt.%, < 0.1 wt.%, < 100 ppmw, and < 50 ppmw. In some aspects, the concentration of one or more of the chemical components listed in this paragraph can be undetectable using currently available analytical techniques.

[0065] Further, the cost-effective hydrolysis and lactonization of 3PN to the gamma-lactone GVL provides utilization of the unsaturated nitrile 3PN in non-nylon applications. The GVL of the present method can be useful as a bio-degradable solvent in semiconductor / electronic parts cleaning, paints & dyes, petrochemical extractions, and the like. Conventionally employed solvents in these industries, such as N-methyl-2-pyrrolidone (NMP), N,N’-dimethylpropyleneurea (DMPU), dimethylacetamide (DMAc), dimethylformamide (DMF),Docket No. INV-24032-WO-PCT dimethylsulfoxide (DMSO), and acetone, are environmentally unfriendly solvents. The gamma-lactone of the present method can be a viable substitute as a drop-in-replacement for these solvents.

[0066] The following, non-limiting aspects of the present disclosure solve the challenges and provide the benefits discussed herein, among others.

[0067] Aspect 1 provides a method of forming gamma valerolactone (GVL), the method comprising:contacting within a first reactor a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture comprising pentenoic acid and ammonia is formed;separating substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed; andcontacting within a second reactor the intermediate mixture with a heterogeneous catalyst whereby a second product mixture comprising GVL is formed.

[0068] Aspect 2 provides the method according to claim 1, wherein substantially all ammonia from the first product mixture, separated from the pentenoic acid, is greater than 95 weight percentage (wt%) of the ammonia produced during the contacting the first stream of 3PN within the first reactor.

[0069] Aspect 3 provides the method according to any of claims 1 and 2, wherein the heterogenous catalyst includes at least one of a solid acid catalyst, a metallic catalyst, an acid, or a combination thereof.

[0070] Aspect 4 provides the method according to any of claims 1 to 3, wherein the heterogenous catalyst includes an ion exchange resin including a copolymer.

[0071] Aspect 5 provides the method according to claim 4, wherein the copolymer includes styrene-divinylbenzene.

[0072] Aspect 6 provides the method according to any of claims 4 and 5, wherein the copolymer includes tetrafluoroethylene and perfluorinated vinyl ether.

[0073] Aspect 7 provides the method according to any of claims 1 to 6, wherein the first pressure is within a range of 100 pounds per square inch absolute (psia) and 2000 psia.

[0074] Aspect 8 provides the method according to any of claims 1 to 7, wherein the method is continuous.

[0075] Aspect 9 provides the method according to any of claims 1 to 8, further comprising purifying the GVL to a purity greater than 85 weight percentage (wt%).Docket No. INV-24032-WO-PCT

[0076] Aspect 10 provides the method according to any of claims 1 to 9, wherein the second temperature is within a range of 100 °C to 150 °C.

[0077] Aspect 11 provides a system for forming gamma valerolactone (GVL), the system comprising:a first reactor configured to combine a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture comprising pentenoic acid and ammonia is formed;a gas flushing apparatus configured to separate substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed; anda second reactor configured to combine the intermediate mixture with a heterogeneous catalyst, whereby a second product mixture comprising GVL is formed.

[0078] Aspect 12 provides the system according to claim 11, wherein the gas flushing apparatus is configured to separate, from the pentenoic acid, greater than 95 weight percentage (wt%) of the ammonia produced during the contacting the first stream of 3PN within the first reactor.

[0079] Aspect 13 provides the system according to any of claims 11 and 12, wherein the heterogenous catalyst includes at least one of a solid acid catalyst, a metallic catalyst, an acid, or a combination thereof.

[0080] Aspect 14 provides the system according to any of claims 11 to 13, wherein the heterogenous catalyst includes an ion exchange resin including a copolymer.

[0081] Aspect 15 provides the system according to claim 14, wherein the copolymer includes styrene-divinylbenzene.

[0082] Aspect 16 provides the system according to any of claims 14 and 15, wherein the copolymer includes tetrafluoroethylene and perfluorinated vinyl ether.

[0083] Aspect 17 provides the system according to any of claims claim 11 to 16, wherein the first pressure is within a range of 100 pounds per square inch absolute (psia) and 2000 psia.

[0084] Aspect 18 provides the system according to any of claims 11 to 17, comprising a purification column configured to purify the GVL to a purity greater than 85 weight percentage (wt%).

[0085] Aspect 19 provides the system according to any of claims 11 to 18, wherein the second temperature is within a range of 100 °C to 150 °C.Docket No. INV-24032-WO-PCT

[0086] Aspect 20 provides a system for forming gamma valerolactone (GVL), the system comprising:means for contacting within a first reactor a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture comprising pentenoic acid and ammonia is formed;means for separating substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed; andmeans for contacting within a second reactor the intermediate mixture with a heterogeneous catalyst whereby a second product mixture comprising GVL is formed.

[0087] Aspect 21 is at least one machine-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement the method of any of Aspects 1-10.

[0088] Aspect 22 is an apparatus comprising means to implement the method of any of Aspects 1-10.

[0089] Aspect 23 is a system to implement the method of any of Aspects 1-10.

[0090] Aspect 24 is a method to implement the system of any of Aspects 11-20.

[0091] The above Detailed Description can include references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific aspects in which the invention can be practiced. These aspects are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0092] In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that can include elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim.Docket No. INV-24032-WO-PCT

[0093] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other aspects can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed aspect. Thus, the following claims are hereby incorporated into the Detailed Description as examples or aspects, with each claim standing on its own as a separate aspect, and it is contemplated that such aspects can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

Docket No. INV-24032-WO-PCT CLAIMSWhat is claimed is:

1. A method of forming gamma valerolactone (GVL), the method comprising:contacting within a first reactor a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture comprising pentenoic acid and ammonia is formed;separating substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed; andcontacting within a second reactor the intermediate mixture with a heterogeneous catalyst whereby a second product mixture comprising GVL is formed.

2. The method of claim 1, wherein substantially all ammonia from the first product mixture, separated from the pentenoic acid, is greater than 95 weight percentage (wt%) of the ammonia produced during the contacting the first stream of 3PN within the first reactor.

3. The method of claim 1, wherein the heterogenous catalyst includes at least one of a solid acid catalyst, a metallic catalyst, an acid, or a combination thereof.

4. The method of claim 1, wherein the heterogenous catalyst includes an ion exchange resin including a copolymer.

5. The method of claim 4, wherein the copolymer includes styrene-divinylbenzene.

6. The method of claim 4, wherein the copolymer includes tetrafluoroethylene and perfluorinated vinyl ether.

7. The method of claim 1, wherein the first pressure is within a range of 100 pounds per square inch absolute (psia) and 2000 psia.

8. The method of claim 1, wherein the method is continuous.Docket No. INV-24032-WO-PCT 9. The method of claim 1, further comprising purifying the GVL to a purity greater than 85 weight percentage (wt%).

10. The method of claim 1, wherein the second temperature is within a range of 100 °C to 150 °C.

11. A system for forming gamma valerolactone (GVL), the system comprising:a first reactor configured to combine a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture comprising pentenoic acid and ammonia is formed;a gas flushing apparatus configured to separate substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed; anda second reactor configured to combine the intermediate mixture with a heterogeneous catalyst, whereby a second product mixture comprising GVL is formed.

12. The system of claim 11, wherein the gas flushing apparatus is configured to separate, from the pentenoic acid, greater than 95 weight percentage (wt%) of the ammonia produced during the contacting the first stream of 3PN within the first reactor.

13. The system of claim 11, wherein the heterogenous catalyst includes at least one of a solid acid catalyst, a metallic catalyst, an acid, or a combination thereof.

14. The system of claim 11, wherein the heterogenous catalyst includes an ion exchange resin including a copolymer.

15. The system of claim 14, wherein the copolymer includes styrene-divinylbenzene.

16. The system of claim 14, wherein the copolymer includes tetrafluoroethylene and perfluorinated vinyl ether.

17. The system of claim 11, wherein the first pressure is within a range of 100 pounds per square inch absolute (psia) and 2000 psia.Docket No. INV-24032-WO-PCT 18. The system of claim 11, comprising a purification column configured to purify the GVL to a purity greater than 85 weight percentage (wt%).

19. The system of claim 11, wherein the second temperature is within a range of 100 °C to 150 °C.

20. A system for forming gamma valerolactone (GVL), the system comprising:means for contacting within a first reactor a first stream of trans 3 -pentenenitrile (3PN) with a first stream of water at a first temperature within a range of 200 °C to 300°C and under a first pressure, whereby a first product mixture comprising pentenoic acid and ammonia is formed;means for separating substantially all ammonia from the first product mixture, whereby an intermediate mixture is formed; andmeans for contacting within a second reactor the intermediate mixture with a heterogeneous catalyst whereby a second product mixture comprising GVL is formed.

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