Conversion of dinitriles to dicarboxylic acids

Abstract

A method of making a dicarboxylic acid includes flowing one or more input streams including one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor, the reaction zone including water. The method includes maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the reaction zone conditions include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The method includes flowing one or more output streams including the one or more C4-C10 dicarboxylic acids from the reactor.

Description

INV-23014-WO-PCTCONVERSION OF DINITRILES TO DICARBOXYLIC ACIDSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 763,933 filed Feb. 27, 2025, the disclosure of which is incorporated herein in its entirety by reference.BACKGROUND

[0002] The production of dicarboxylic acids, such as adipic acid, is a critical process in the chemical industry, primarily due to their use in the manufacture of nylon, plasticizers, and other polymers. Traditionally, adipic acid is produced from cyclohexane through a nitric acid oxidation process. However, this conventional method is associated with significant environmental concerns, particularly the emission of nitrous oxide (N2O), a potent greenhouse gas with a global warming potential approximately 290 times that of carbon dioxide (CO2).

[0003] Efforts to mitigate these emissions have led to the development of N2O abatement technologies, but these solutions often add complexity and cost to the production process. Additionally, the conventional process relies on fossil fuel-derived feedstocks, which further contributes to its carbon footprint.

[0004] As such, alternative methods and apparatuses for forming dicarboxylic acids are needed that have reduced environmental impact.SUMMARY OF THE INVENTION

[0005] Various aspects of the present disclosure provide a method of making a dicarboxylic acid including flowing one or more input streams including one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor. The reaction zone includes water. The method includes maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids. The reaction zone conditions include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zoneINV-23014-WO-PCTconditions. The method also includes flowing one or more output streams including the one or more C4-C10 dicarboxylic acids from the reactor.

[0006] Various aspects of the present disclosure provide a method of making adipic acid including flowing one or more input streams including adiponitrile to a reaction zone of a reactor, the reaction zone including water, wherein the one or more input streams are the only input streams to the reaction zone and wherein the one or more input streams are substantially free of catalysts. The method includes maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the adiponitrile to adipic acid. The reaction zone conditions include a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm. The method also includes flowing one or more output streams including the adipic acid from the reactor.

[0007] Various aspects of the present disclosure provide a method of making adipic acid including flowing one or more input streams including adiponitrile to a reaction zone of a reactor, the reaction zone including water, wherein the one or more input streams include a purge gas that is an inert gas. The method includes maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the adiponitrile to adipic acid. The reaction zone conditions include a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm. The method also includes flowing one or more output streams including the adipic acid from the reactor, wherein the one or more output streams include the purge gas and ammonia.

[0008] Various aspects of the present disclosure provide an apparatus for making a dicarboxylic acid including one or more input flow channels configured to flow one or more input streams including one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor. The reactor includes the reaction zone, and the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids. The reaction zone conditions include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The apparatus also includes one or more output flow channels configured to flow one or more output streams including the one or more C4-C10 dicarboxylic acids from the reactor.INV-23014-WO-PCT

[0009] Various aspects of the present disclosure provide an apparatus for making adipic acid including one or more input flow channels configured to flow one or more input streams including adiponitrile to a reaction zone of a reactor, wherein the one or more input streams are the only input streams to the reaction zone and wherein the one or more input streams are substantially free of catalysts. The reactor includes the reaction zone, and the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of adiponitrile to adipic acid. The reaction zone conditions include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The apparatus also includes one or more output flow channels configured to flow one or more output streams including the adipic acid from the reactor.

[0010] Various aspects of the present disclosure provide an apparatus for making adipic acid including one or more input flow channels configured to flow one or more input streams including adiponitrile to a reaction zone of a reactor, wherein the one or more input streams include a purge gas that is an inert gas. The reactor includes the reaction zone, and the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of adiponitrile to adipic acid. The reaction zone conditions include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The apparatus also includes one or more output flow channels configured to flow one or more output streams including the adipic acid from the reactor, wherein the one or more output streams include the purge gas and ammonia.

[0011] Various aspects of the present disclosure provide an apparatus for making a dicarboxylic acid including one or more reactor input flow channels configured to flow one or more reactor input streams including one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor. The reactor includes the reaction zone. The reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids. The reaction zone conditions include a temperature greater than or equalINV-23014-WO-PCTto ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The reactor includes a reactor inlet purge stream conduit configured to allow a purge gas to enter the reaction zone, and the reactor includes a reactor output purge stream conduit configured to allow an ammonia-rich purge stream to exit the reaction zone. The apparatus includes one or more reactor output flow channels configured to flow one or more reactor output streams including the one or more C4-C10 dicarboxylic acids from the reactor. The apparatus includes a separator unit configured to accept the one or more reactor output streams including the one or more C4-C10 dicarboxylic acids from the reactor, and configured to output an organic stream and an aqueous stream including the one or more C4-C10 dicarboxylic acids, wherein the separator unit is a liquid-liquid separator unit. The apparatus includes a vacuum distillation unit configured to accept the organic stream and to output a lower-boiling organic constituents stream and a higher-boiling constituents stream including unconverted C4-C10 aliphatic dinitrile. The apparatus includes a higher-boiling constituents flow channel configured to flow the higher-boiling constituents stream to the one or more reactor input flow channels. The apparatus includes an evaporator unit configured to accept the aqueous stream including the one or more C4-C10 dicarboxylic acids and to output water and a concentrated slurry stream including the one or more C4-C10 dicarboxylic acids. The apparatus includes a concentrated slurry stream separation unit configured to accept the concentrated slurry stream and to output a filtrate stream and a solid product stream including the one or more C4-C10 dicarboxylic acids. The apparatus includes a filtrate flow channel configured to flow the filtrate to the one or more reactor input channels. The apparatus includes a washing unit configured to accept the solid product stream and water, and to output used water and washed solid product stream that includes the one or more C4-C10 dicarboxylic acids. The apparatus also includes a drying unit configured to accept the washed solid product stream and to output a dried solid product stream including the one or more C4-C10 dicarboxylic acids.

[0012] Various aspects of the present disclosure provide an apparatus for making a dicarboxylic acid including one or more reactor input flow channels configured to flow one or more reactor input streams including one or more C4-C10 aliphatic dinitriles to a first-stage reaction zone of a first-stage reactor. The apparatus includes the first-stage reactor including the first-stage reaction zone, wherein the first-stage reactor is configured to maintain the first-INV-23014-WO-PCTstage reaction zone at first-stage reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids. The first-stage reaction zone conditions include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the first-stage reaction zone conditions, and the first-stage reaction zone conditions include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the first-stage reaction zone conditions. The first-stage reactor includes a reactor inlet purge stream conduit configured to allow a purge gas to enter the first-stage reaction zone, and the first-stage reactor includes a first-stage reactor output purge stream conduit configured to allow a first-stage ammonia-rich purge stream to exit the first-stage reaction zone. The apparatus includes one or more first-stage reactor output flow channels configured to flow one or more first-stage reactor output streams including the one or more C4-C10 dicarboxylic acids from the first-stage reactor. The apparatus includes a separator unit configured to accept the one or more first-stage reactor output streams including the one or more C4-C10 dicarboxylic acids from the first-stage reactor, and configured to output an organic stream and an aqueous stream including the one or more C4-C10 dicarboxylic acids, wherein the separator unit is a solid-liquid separator unit, and wherein the organic stream is a separated solidified stream. The apparatus includes a washing unit configured to wash the separated solidified stream with water to form a washed separated solidified stream and used water. The apparatus includes a second-stage reactor including a second-stage reaction zone. The second-stage reactor is configured to maintain the second-stage reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of aliphatic dinitriles in the washed separated solidified stream to the corresponding one or more C4-C10 dicarboxylic acids. The second-stage reactor is configured to accept the washed separated solidified stream and a second-stage reactor water stream and output a second-stage reactor effluent stream including the one or more C4-C10 dicarboxylic acids. The second-stage reactor includes a second-stage reactor output purge stream conduit configured to allow a second-stage ammonia-rich purge stream to exit the second-stage reaction zone. The apparatus includes an evaporator unit configured to accept the aqueous stream including the one or more C4-C10 dicarboxylic acids and the second-stage reactor effluent stream, and to output water and a concentrated slurry stream including the one or more C4-C10 dicarboxylic acids. The apparatus includes a concentrated slurry stream separation unit configured to accept the concentrated slurry stream and to output a filtrate stream and a solid productINV-23014-WO-PCTstream including the one or more C4-C10 dicarboxylic acids. The apparatus includes a filtrate flow channel configured to flow the filtrate to the one or more reactor input channels. The apparatus includes a washing unit configured to accept the solid product stream and water, and to output used water and washed solid product stream that includes the one or more C4-C10 dicarboxylic acids. The apparatus also includes a drying unit configured to accept the washed solid product stream and to output a dried solid product stream including the one or more C4-C10 dicarboxylic acids.

[0013] Various aspects of the present disclosure provide certain environmental advantages over other methods and apparatuses for making dicarboxylic acids. For example, various aspects of the present disclosure provide reduced greenhouse gas emissions by eliminating, minimizing, or decreasing the emission of nitrous oxide (N2O), which is a potent greenhouse gas, as compared to conventional dicarboxylic acid production methods such as cycloaliphatic ketone oxidation to make dicarboxylic acids. Various aspects of the present disclosure provide a lower carbon footprint than conventional dicarboxylic acid production methods by avoiding the use of fossil fuel-derived feedstocks and reducing N2O emissions, thereby offering a lower product carbon footprint (PCF) and improved Global Warming Potential (GWP) equivalency.

[0014] Various aspects of the present disclosure provide certain process efficiency advantages over other methods and apparatuses for making dicarboxylic acids. For example, various aspects of the present disclosure provide a high yield of dicarboxylic acid such as adipic acid, and can achieve high conversion rates of the aliphatic dinitrile such as adiponitrile and high selectivity for the dicarboxylic acid such as adipic acid. Various aspects of the present disclosure can form dicarboxylic acids without the need for catalysts, thereby simplifying the reaction and reducing costs associated with catalyst procurement and disposal. During hydrolytic formation of dicarboxylic acids, high levels of ammonia can cause formation of solid ammonium salts which can contaminate the dicarboxylic acid product, be tedious to remove, and reduce yields. Problems with ammonium salt formation can necessitate decreasing the initial concentration of aliphatic dinitrile to reduce the resulting ammonium salt concentration. Various aspects of the present disclosure can include inert gas purging to effectively remove or decrease the concentration of ammonia and by-products derived from ammonia, thereby enhancing yield of the dicarboxylic acid, preventing contamination, simplifying the purification process, and allowing for use of higher initialINV-23014-WO-PCTconcentrations of aliphatic dinitrile and higher resulting final concentrations of the dicarboxylic acid.

[0015] Various aspects of the present disclosure provide certain economic advantages over other methods and apparatuses for making dicarboxylic acids. For example, various aspects of the present disclosure can leverage the availability of aliphatic dinitriles such as adiponitrile to create a commercially viable pathway for dicarboxylic acid production such as adipic acid production. By reducing or eliminating the need for complex N2O abatement technologies and catalysts, various aspects of the present disclosure can lower operational costs.

[0016] Various aspects of the present disclosure provide certain technical advantages over other methods and apparatuses for making dicarboxylic acids. For example, various aspects of the present disclosure can operate under a wide range of temperatures and pressures, providing flexibility and versatility in adapting to different industrial settings.

[0017] Various aspects of the present disclosure are scalable allowing efficient large-scale production while also allowing for smaller-scale dicarboxylic acid production needing less fixed and operating capital. Various aspects of the present disclosure have good turn-up / down ratios allowing production to be efficiently scaled up or down to synchronize with market demand. While the conventional production scales for making dicarboxylic acids from cycloaliphatic feedstocks are large in order to make them cost effective, such large-scale production cannot be efficiently scaled down for reduced production.

[0018] Conventional cycloaliphatic oxidation production methods produce large amounts of undesirable by-products that must be properly disposed of. Examples include non-volatile residue (NVR) and cyclohexane oxidation process (COP) streams containing many unusable and unrecoverable chemical species. These streams also contribute to lower yield of dicarboxylic acid product. Various aspects of the present disclosure avoid the production of these undesirable streams, thereby eliminating the handling / disposal costs associated therewith and improving the overall process yield of dicarboxylic acid product.BRIEF DESCRIPTION OF THE FIGURES

[0019] The drawings illustrate generally, by way of example, but not by way of limitation, various aspects of the present invention.

[0020] FIG. l is a schematic representation of a method and apparatus for making a dicarboxylic acid, in accordance with various aspects.INV-23014-WO-PCT

[0021] FIG. 2 is a schematic representation of a method and apparatus for making a dicarboxylic acid, in accordance with various aspects.DETAILED DESCRIPTION OF THE INVENTION

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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 ofINV-23014-WO-PCTdoing 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.

[0026] 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.

[0027] 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%.Method of making a dicarboxylic acid.

[0028] Various aspects of the present disclosure provide a method of making a dicarboxylic acid. The method can include flowing one or more input streams including one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor. The reaction zone includes water, which is water that is already present in the reaction zone, water that is added to the reaction zone via the one or more input streams, or a combination thereof. The method can include maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids via hydrolysis. The reaction zone conditions can include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions. The reaction zone conditions can include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The method can also include flowing one or more output streams including the one or more C4-C10 dicarboxylic acids from the reactor.

[0029] The reaction zone can be free of ultrasonic irradiation. Ultrasonic irradiation is a process that uses sound waves with frequencies above about 20,000 Hz to create localized areas of high heat and pressure. Such sound waves passing through a liquid create microbubbles that grow and collapse quickly, a process called cavitation. The rapid collapseINV-23014-WO-PCTof the microbubbles can create shock waves and free radicals, and localized areas of high pressure and temperature. The reaction zone can be free of cavitation.

[0030] The one or more input streams can include water. The one or more input streams can be the source of all of the water in the reaction zone. In various aspects, the reaction zone already includes some water and the one or more input streams can increase the amount of water in the reaction zone. In various aspects, the reaction zone already includes water and the one or more input streams are substantially free of water.

[0031] The one or more input streams can include a purge gas. The purge gas can sparge the reaction zone to remove / purge / disengage from the reaction zone some or all of the ammonia generated during the hydrolytic conversion of the aliphatic dinitrile to the dicarboxylic acid. The purge gas can be any suitable purge gas. The purge gas can include steam, or the purge gas can be substantially free of steam. The purge gas can be or include an inert gas. The purge gas can be or include nitrogen, argon, helium, CO2, or a combination thereof. The purge gas can be or include nitrogen. In various aspects, steam can be generated from the water in the reaction zone and / or the one or more input streams can include steam, and the steam can function as a purge gas, such as in addition to the purge gas added in the one or more input streams. In various aspects, the one or more input streams include a nitrogen purge gas, and the one or more input streams are substantially free of steam. In various aspects, the one or more input streams are substantially free of a purge gas, and steam generated from the water in the reaction zone can be the only or the primary purge gas to remove / purge / disengage from the reaction zone some or all of the ammonia generated during the hydrolytic conversion of the aliphatic dinitrile to the dicarboxylic acid. In various aspects the method of the present disclosure can include removal of 50 wt% to 100 wt% of the ammonia generated in the reaction zone, or 80 wt% to 100 wt%, or 95 wt% to 100 wt%, or less than or equal to 100 wt% and greater than or equal to 50 wt% and less than, equal to, or greater than 55 wt%, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.9, or 99.99 wt%. The removal of ammonia can prevent or reduce the formation of ammonium salts. The removal of ammonia can drive the dinitrile hydrolysis toward completion, thereby increasing conversion of the dinitrile and yield of the dicarboxylic acid.

[0032] In aspects including a purge gas in the one or more input streams, the purge gas can be added to the reaction zone at any suitable rate. For example, the purge gas can be added to the reaction zone at a rate of 1-1000 SCCM per 30 g to 60 g (e.g., less than or equal to 60 g and greater than or equal to 30 g and less than, equal to, or greater than 32 g, 34, 36,INV-23014-WO-PCT38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 g) of aliphatic dinitrile added to the reaction zone via the one or more input streams, or 300-600 SCCM (standard cubic centimeters per minute) per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams, or less than or equal to 1000 SCCM and greater than or equal to 1 SCCM and less than, equal to, or greater than 2 SCCM, 4, 6, 8, 10, 15, 20, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, or 950 SCCM per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams.

[0033] The one or more input streams can include a gaseous input stream including the purge gas. The gaseous input stream can be entirely or mostly one or more gases. The method can include adding the purge gas to the reaction zone in any suitable manner, such as via a sparging apparatus, such as via a tube, nozzle, or a porous metal structure. The sparging apparatus can be located in any suitable location, such as a location at or near a bottom of the reaction zone, or at a location in a middle or lower half of the reaction zone. The purge gas can be added to the reaction zone via a tube, a diffuser, a sparging rod, a sintered metal sparger, a ring sparger, a micro sparger, or an in-line sparger. The one or more input streams can include a liquid input stream that is entirely or mostly one or more liquids and that includes the aliphatic dinitrile. In various aspects, the one or more input streams include a combined input stream that includes one or more liquids and one or more gases that includes both the purge gas and the aliphatic dinitrile.

[0034] The one or more input streams can include a catalyst. As used herein, a catalyst is a chemical compound that increases the rate of the hydrolysis reaction of the aliphatic dinitrile to form the dicarboxylic acid. The catalyst can be any suitable catalyst that increases the rate of the hydrolysis reaction of the aliphatic dinitrile to form the dicarboxylic acid. The catalyst can be not consumed by the hydrolysis reaction and can remain unchanged after it. The catalyst can include an acid catalyst. The acid catalyst can include any suitable acid, such as a mineral acid, an organic acid, or a combination thereof. The acid catalyst can include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, perchloric acid, citric acid, acetic acid, formic acid, lactic acid, malic acid, tartaric acid, oxalic acid, or a combination thereof. The acid catalyst can include NH4H2PO4, H3PO4, or a combination thereof. The catalyst can include a basic catalyst. The basic catalyst can include potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, ammonium phosphate, ammonium hydroxide, sodium hydroxide, or a combination thereof. The basic catalyst can include NH4OH. The catalyst can include CO2 (e.g., which can formINV-23014-WO-PCTcarbonic acid in water which functions as a catalyst), tungstated zirconia (W / Zr), zeolite Y, zeolite Beta, Zeolite MFI, ammonium bicarbonate ((NH3)HCO3), ammonium carbonate ((NH3)2CO3), or a combination thereof. The catalyst can include any combination of catalysts described herein.

[0035] The catalyst can be present in the one or more input streams in any suitable amount relative to the amount of aliphatic dinitrile in the one or more input streams. The catalyst can be present in the one or more input streams in an amount that is 0.001 wt% to 30 wt% based on the amount of aliphatic dinitrile in the one or more input streams, or 0.1 wt% to 5 wt%, or less than or equal to 30 wt% and greater than or equal to 0.001 wt% or less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, or 28 wt% based on the amount of aliphatic dinitrile in the one or more input streams.

[0036] The one or more input streams can be the only input streams to the reaction zone. The one or more input streams can be substantially free of catalysts, such as any catalyst described herein. For example, catalysts can be 0 wt% to 1 wt% of the one or more input streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more input streams. The one or more input streams can be substantially free of diamines, such as diamines suitable for forming a polyamide by reacting with the dicarboxylic acid, such as C4-C10 diamines, such as hexamethylene diamine. Diamines can be 0 wt% to 1 wt% of the one or more input streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more input streams. The one or more input streams can be substantially free of alcohols, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, or a combination thereof. Alcohols can be 0 wt% to 1 wt% of the one or more input streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more input streams. In various aspects, other than optional water, optional purge gas, and optional catalyst, the aliphatic dinitrile is 95 wt% to 100 wt% of the one or more input streams, or 100 wt% of the one or more input streams, or less than or equal to 100 wt% and greater than or equal to 95 wt% and less than, equal to, or greater than 95.5INV-23014-WO-PCTwt%, 96, 96.5, 97, 97.5, 98, 98.5, 99, 99.5, 99.6, 99.7, 99.8, 99.9, or 99.99 wt% of the one or more input streams.

[0037] The one or more output streams can include water. The one or more output streams can include a purge gas, such as a purge gas added to the one or more input streams (e.g., an inert gas, steam, or a combination there), a purge gas generated in the reaction chamber (e.g., steam), or a combination thereof. The one or more output streams can include ammonia generated during the hydrolysis of the aliphatic dinitrile to form the dicarboxylic acid, such as ammonia entrained in one or more purge gases. In aspects wherein a catalyst is included in the one or more input streams, the one or more output streams can include a catalyst. The one or more output streams can include a gaseous output stream that is entirely or predominantly one or more gases, wherein the gaseous output stream includes one or more purge gases and ammonia. The gaseous output steam can flow from the reactor near or at a top of the reactor. The one or more output streams can include a liquid output stream that is entirely or predominantly one or more liquids, wherein the liquid output stream includes the dicarboxylic acid. The one or more output streams can include a combined output stream that is a combination of one or more gases and one or more liquids and that includes the dicarboxylic acid, one or more purge gases, and ammonia.

[0038] The one or more output streams can be the only output streams from the reaction zone. The one or more output streams can be substantially free of catalysts, such as any catalyst described herein. For example, catalysts can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. The one or more output streams can be substantially free of diamines, such as diamines suitable for forming a polyamide by reacting with the dicarboxylic acid, such as C4-C10 diamines, such as hexamethylene diamine. For example, diamines can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. The one or more output streams can be substantially free of polyamides, such as nylon 66. For example, polyamides can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%,INV-23014-WO-PCT0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. In various aspects, the one or more output streams can be substantially free of acids other than the dicarboxylic acid. For example, acids other than the dicarboxylic acid can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. In various aspects, the one or more output streams can be substantially free of mineral acids. For example, mineral acids can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. Other than optional water, optional purge gas, optional unreacted aliphatic dinitrile, optional catalyst, and ammonia, the carboxylic acid can be 10 wt% to 100 wt% of the one or more output streams, or 50 wt% to 95 wt%, or less than or equal to 100 wt% or greater than or equal to 10 wt% and less than, equal to, or greater than 15 wt%, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99 wt% of the one or more output streams.

[0039] The one or more input streams can include any suitable concentration of the aliphatic dinitrile. For example, the one or more input streams can include a concentration of the aliphatic dinitrile in water of 0.1 wt% to 50 wt%, or 1 wt% to 40 wt%, 1 wt% to 30 wt%, or 5 wt% to 20 wt%, or less than or equal to 50 wt% and greater than or equal to 0.1 wt% and less than, equal to, or greater than 0.5 wt%, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, or 48 wt%.

[0040] The method can include any suitable conversion of the aliphatic dinitrile (e.g., a conversion per pass through the one or more reactors), such as a conversion of the aliphatic dinitrile of 10% to 100%, or 90% to 100%, or less than or equal to 100% and greater than or equal to 10% and less than, equal to, or greater than 12%, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, or 99.9%. The method can include any suitable selectivity of the aliphatic dinitrile to the carboxylic acid, such as a selectivity of 50% to 100%, or 80% to 100%, or less than or equal to 100% and greater than or equal to 50% and less than, equal to, or greater than 52%, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99%. The method can include any suitable yield of the carboxylic acidINV-23014-WO-PCTfrom the aliphatic dinitrile, such as a yield of 10% to 100%, or 50% to 95%, or less than or equal to 100% and greater than or equal to 10% and less than, equal to, or greater than 12%, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, or 99.9%.

[0041] The method can include exposing the materials in the reaction zone to reaction zone conditions for any suitable reaction duration, such as a reaction duration of 0.01 h to 100 h, 1 h to 10 h, 1 h to 8 h, or less than or equal to 100 h and greater than or equal to 0.01 h and less than, equal to, or greater than 0.05 h, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 h. The reaction zone conditions can include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions. The reaction zone conditions can include a temperature of greater than or equal to 0 °C to less than or equal to 373 °C, or 220 °C to 300 °C, or less than or equal to 373 °C and greater than or equal to 0 °C and less than, equal to, or greater than 10 °C, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 330, 340, 350, 360, or 370 °C. The reaction zone conditions can include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The reaction zone conditions can include a pressure of 1 atm to 218 atm, or 30 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 1 atm and less than, equal to, or greater than 5 atm, 10, 15, 20, 25, 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, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm. The method can include maintaining the reaction zone conditions at a first pressure, and then maintaining the reaction zone conditions at a second pressure. In various aspects, the first pressure can be a higher pressure, and the second subsequent pressure can be a lower pressure. For example, the reaction zone conditions can include a first pressure of 100 atm to 218 atm, or 150 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 100 atm and less than, equal to, or greater than 105 atm, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm, and then a second pressure of 1 atm to 100 atm, 30 atm to 100 atm, or less than or equal to 100 atm and greater than or equal to 30 atm and less than, equal to, or greater than 35 atm, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 atm.INV-23014-WO-PCT

[0042] The aliphatic dinitrile can be any suitable C4-C10 aliphatic dinitrile. The aliphatic dinitrile can be succinonitrile, glutaronitrile, adiponitrile, 2-methylglutaronitrile, or 2-ethylsuccinonitrile. The aliphatic dinitrile can be, or can be derived from, any suitable aliphatic dinitrile, such as purified dinitrile obtained from a fossil-fuel feedstock conversion process, purified dinitrile obtained from a biological feedstock conversion process, semirefined dinitrile, crude dinitrile, diluted aqueous dinitrile stream, by-product dinitrile, a waste dinitrile stream, or a combination thereof. The dicarboxylic acid can be any suitable C4-C10 dicarboxylic acid that is the hydrolysis product of the C4-C10 aliphatic dinitrile. The dicarboxylic acid can be succinic acid, glutaric acid, adipic acid, 2-methylglutaric acid, or 2-ethylsuccinic acid.

[0043] In various aspects, the aliphatic dinitrile is adiponitrile and the dicarboxylic acid is adipic acid. In such aspects, the one or more output streams can further include, in addition to the dicarboxylic acid, cyanovaleramide, cyanovaleric acid, adipamide, adipamic acid, 2-cyanocyclopetylideneimine, cyclopentanone, or a combination thereof. Mixed streams containing various dinitriles can produce mixed streams containing the corresponding carboxylic acids. For example, in various aspects, the aliphatic dinitrile feed can include a mixture of adiponitrile and 2-methylglutaronitrile, and the one or more dicarboxylic acids can be a mixture of adipic acid and 2-methylglutaric acid.

[0044] The method can be a continuous process for making the dicarboxylic acid, wherein the one or more input streams continuously feed the aliphatic dinitrile to the reaction zone and the one or more output streams continuously flow the dicarboxylic acid from the reaction zone. In other aspects, the method can be a batch or semi-batch process for making the dicarboxylic acid, wherein the one or more input streams periodically feed the aliphatic dinitrile to the reaction one and the one or more output streams periodically flow the dicarboxylic acid from the reaction zone.

[0045] The reactor can be any suitable reactor that can carry out the method for forming the dicarboxylic acid from the aliphatic dinitrile. For example, the reactor can include an autoclave, a column, a tubular reactor, a tank reactor, a plug flow reactor, a packed bed reactor, a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, or a bubble column reactor. The reaction zone can be a compartment within the reactor. The method can include agitating materials in the reaction zone. The agitation can be conducted in any suitable manner. Agitation can occur as the result of a purge gas being sparged into the reaction zone, agitation can occur as a result ofINV-23014-WO-PCTstirring the reaction zone contents, agitation can be induced from internal draft tube circulation, agitation can be induced from external circulation loop methods, or a combination thereof.

[0046] The method can further include recovering the dicarboxylic acid from the reaction zone and / or from the one or more output streams. Recovering the dicarboxylic acid can include distillative separation, evaporative separation, wiped-film evaporation, short-path distillation, solvent extraction, cryogenic separation, crystallization, filtration, membrane separation, or a combination thereof. Recovering the dicarboxylic acid can include rotary drum separation, centrifugation, decantation, vacuum filtration, pressure filtration, aqueously washing the one or more C4-C10 dicarboxylic acids, drying the one or more C4-C10 dicarboxylic acids, or a combination thereof.

[0047] The method can be more environmentally friendly than other processes for forming dicarboxylic acid, such as a process for making the dicarboxylic acid by hydrocarbon feedstock oxidation. For example, the method of the present disclosure can form a lower mass of CO2 equivalents per mass of the formed dicarboxylic acid. In various aspects, the method can have a Global Warming Potential (GWP) Equivalency, determined in terms of kg CO2 equivalents per kg of the formed dicarboxylic acid, that is 0.1% to 99% of that of a process of making the same dicarboxylic acid product by a hydrocarbon feedstock oxidation (e.g., oxidation of cyclohexanone feedstock to produce adipic acid), or 0.1% to 10%, or less than or equal to 99% and greater than or equal to 0.1% and less than, equal to, or greater than 0.5%, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95% of that of a process of making the same dicarboxylic acid product by a hydrocarbon feedstock oxidation.

[0048] In various aspects, the method can include the use of multiple reactors, such as in series or in parallel, for increased efficient conversion of the dinitrile and increased yield of the dicarboxylic acid.

[0049] In various aspects, the reactor can be a first-stage reactor and the reaction zone can be a first-stage reaction zone. The one or more output streams can include unreacted dinitriles in addition to the one or more C4-C10 dicarboxylic acids. The method can further include separating the unreacted dinitriles and the one or more C4-C10 dicarboxylic acids to form an organic stream including the unreacted dinitriles and an aqueous stream including the one or more C4-C10 dicarboxylic acids. The method can include flowing the organic stream to a second-stage reaction zone of a second-stage reactor, wherein the second-stage reactionINV-23014-WO-PCTzone includes water, and maintaining conditions of the second-stage reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids. The second-stage reaction zone conditions can include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the second-stage reaction zone conditions. The second-stage reaction zone conditions can include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the second-stage reaction zone conditions. The method can include flowing one or more second output streams including the one or more C4-C10 dicarboxylic acids from the second-stage reactor.

[0050] The method can include adding a purge gas to the second-stage reaction zone. The purge gas can sparge the reaction zone to remove / purge / disengage from the second-stage reaction zone some or all of the ammonia generated during the hydrolytic conversion of the aliphatic dinitrile to the dicarboxylic acid. The purge gas can be any suitable purge gas. The purge gas can include steam, or the purge gas can be substantially free of steam. The purge gas can be or include an inert gas. The purge gas can be or include nitrogen, argon, helium, CO2, or a combination thereof. The purge gas can be or include nitrogen. In various aspects, steam can be generated from the water in the second-stage reaction zone the generated steam can function as a purge gas, such as in addition to any purge gas added to the second reaction zone. In various aspects, an inert gas such as nitrogen is added to the second-stage reaction zone as a purge gas, and no steam is added to the second-stage reaction zone. In various aspects, no purge gas is added to the second-stage reaction zone, and steam generated from the water in the second-stage reaction zone can be the only or the primary purge gas to remove / purge / disengage from the second-stage reaction zone some or all of the ammonia generated during the hydrolytic conversion of the aliphatic dinitrile to the dicarboxylic acid. In various aspects the method of the present disclosure can include removal of 50 wt% to 100 wt% of the ammonia generated in the second-stage reaction zone, or 80 wt% to 100 wt%, or 95 wt% to 100 wt%, or less than or equal to 100 wt% and greater than or equal to 50 wt% and less than, equal to, or greater than 55 wt%, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.9, or 99.99 wt%. The removal of ammonia can prevent or reduce the formation of ammonium salts. The removal of ammonia can drive the dinitrile hydrolysis toward completion, thereby increasing conversion of the dinitrile and yield of the dicarboxylic acid.INV-23014-WO-PCT

[0051] The purge gas can be added to the second-stage reaction zone at any suitable rate. For example, the purge gas can be added to the second-stage reaction zone at a rate of 1-1000 SCCM per 30 g to 60 g (e.g., less than or equal to 60 g and greater than or equal to 30 g and less than, equal to, or greater than 32 g, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 g) of aliphatic dinitrile added to the second-stage reaction zone, or 300-600 SCCM (standard cubic centimeters per minute) per 30 g to 60 g of aliphatic dinitrile added to the second-stage reaction zone, or less than or equal to 1000 SCCM and greater than or equal to 1 SCCM and less than, equal to, or greater than 2 SCCM, 4, 6, 8, 10, 15, 20, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, or 950 SCCM per 30 g to 60 g of aliphatic dinitrile added to the second-stage reaction zone.

[0052] The method can include adding the purge gas to the second-stage reaction zone in any suitable manner, such as via a sparging apparatus, such as via a tube, nozzle, or a porous metal structure. The sparging apparatus can be located in any suitable location, such as a location at or near a bottom of the second-stage reaction zone, or at a location in a middle or lower half of the second-stage reaction zone. The purge gas can be added to the second-stage reaction zone via a tube, a diffuser, a sparging rod, a sintered metal sparger, a ring sparger, a micro sparger, or an in-line sparger.

[0053] The method can include exposing the materials in the second-stage reaction zone to second-stage reaction zone conditions for any reaction duration, such as a reaction duration of 0.01 h to 100 h, 1 h to 10 h, 1 h to 8 h, or less than or equal to 100 h and greater than or equal to 0.01 h and less than, equal to, or greater than 0.05 h, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 h. The second-stage reaction zone conditions can include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions. The second-stage reaction zone conditions can include a temperature of greater than or equal to 0 °C to less than or equal to 373 °C, or 220 °C to 300 °C, or less than or equal to 373 °C and greater than or equal to 0 °C and less than, equal to, or greater than 10 °C, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 330, 340, 350, 360, or 370 °C. The second-stage reaction zone conditions can include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The second-stage reaction zone conditions can include aINV-23014-WO-PCTpressure of 1 atm to 218 atm, or 30 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 1 atm and less than, equal to, or greater than 5 atm, 10, 15, 20, 25, 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, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm. The method can include maintaining the second-stage reaction zone conditions at a first pressure, and then maintaining the second-stage reaction zone conditions at a second pressure. In various aspects, the first pressure can be a higher pressure, and the second subsequent pressure can be a lower pressure. For example, the second-stage reaction zone conditions can include a first pressure of 100 atm to 218 atm, or 150 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 100 atm and less than, equal to, or greater than 105 atm, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm, and then a second pressure of 1 atm to 100 atm, 30 atm to 100 atm, or less than or equal to 100 atm and greater than or equal to 30 atm and less than, equal to, or greater than 35 atm, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 atm.

[0054] The method can include combining the one or more C4-C10 dicarboxylic acids from the second-stage reactor with the one or more C4-C10 dicarboxylic acids from the first-stage reactor (e.g., the aqueous stream including the one or more C4-C10 dicarboxylic acids) to form a product stream. The method can include recovering the one or more C4-C10 dicarboxylic acids from the product stream. The recovery can be performed in any suitable way, such as including rotary drum separation, centrifugation, decantation, vacuum filtration, pressure filtration, aqueously washing the one or more C4-C10 dicarboxylic acids, drying the one or more C4-C10 dicarboxylic acids, or a combination thereof.Apparatus for making a dicarboxylic acid.

[0055] Various aspects of the present invention provide an apparatus for making a dicarboxylic acid. The apparatus can be any suitable apparatus that can carry out the method of the present disclosure for hydrolytically forming the dicarboxylic acid from the aliphatic dinitrile. For example, the apparatus can include one or more input flow channels configured to flow one or more input streams including one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor. The reactor includes the reaction zone. The reactor can be configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids. The reaction zone conditions can include a temperature greaterINV-23014-WO-PCTthan or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions can include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The apparatus can include one or more output flow channels configured to flow one or more output streams including the one or more C4-C10 dicarboxylic acids from the reactor.

[0056] The one or more input streams can include water. The one or more input streams can be the source of the water in the reaction zone. In various aspects, the reaction zone already includes some water and the one or more input streams can increase the amount of water in the reaction zone. In various aspects, the reaction zone already includes water and the one or more input streams are substantially free of water.

[0057] The aliphatic dinitrile can be any suitable C4-C10 aliphatic dinitrile. The aliphatic dinitrile can be succinonitrile, glutaronitrile, adiponitrile, 2-methylglutaronitrile, or 2-ethylsuccinonitrile. The aliphatic dinitrile can be, or can be derived from, any suitable aliphatic dinitrile, such as purified dinitrile obtained from a fossil-fuel feedstock conversion process, purified dinitrile obtained from a biological feedstock conversion process, semirefined dinitrile, crude dinitrile, diluted aqueous dinitrile stream, by-product dinitrile, a waste dinitrile stream, or a combination thereof. The dicarboxylic acid can be any suitable C4-C10 dicarboxylic acid that is the hydrolysis product of the C4-C10 aliphatic dinitrile. The dicarboxylic acid can be succinic acid, glutaric acid, adipic acid, 2-methylglutaric acid, or 2-ethylsuccinic acid.

[0058] In various aspects, the aliphatic dinitrile is adiponitrile and the dicarboxylic acid is adipic acid. In such aspects, the one or more output streams can further include, in addition to the dicarboxylic acid, cyanovaleramide, cyanovaleric acid, adipamide, adipamic acid, 2-cyanocyclopetylideneimine, cyclopentanone, or a combination thereof. Mixed streams containing various dinitriles can produce mixed streams containing the corresponding carboxylic acids. For example, in various aspects, the aliphatic dinitrile feed can include a mixture of adiponitrile and 2-methylglutaronitrile, and the one or more dicarboxylic acids can be a mixture of adipic acid and 2-methylglutaric acid.

[0059] The catalyst can be present in the one or more input streams in any suitable amount relative to the amount of aliphatic dinitrile in the one or more input streams. The catalyst can be present in the one or more input streams in an amount that is 0.001 wt% to 30 wt% based on the amount of aliphatic dinitrile in the one or more input streams, or 0.1 wt%INV-23014-WO-PCTto 5 wt%, or less than or equal to 30 wt% and greater than or equal to 0.001 wt% or less than, equal to, or greater than 0.005 wt%, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, or 28 wt% based on the amount of aliphatic dinitrile in the one or more input streams.

[0060] The one or more input streams can include any suitable concentration of the aliphatic dinitrile. For example, the one or more input streams can include a concentration of the aliphatic dinitrile in water of 0.1 wt% to 50 wt%, or 1 wt% to 40 wt%, 1 wt% to 30 wt%, or 5 wt% to 20 wt%, or less than or equal to 50 wt% and greater than or equal to 0.1 wt% and less than, equal to, or greater than 0.5 wt%, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, or 48 wt%.

[0061] The one or more input streams can be the only input streams to the reaction zone. The one or more input streams can be substantially free of catalysts, such as any catalyst described herein. For example, catalysts can be 0 wt% to 1 wt% of the one or more input streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more input streams. The one or more input streams can be substantially free of diamines, such as diamines suitable for forming a polyamide by reacting with the dicarboxylic acid, such as C4-C10 diamines, such as hexamethylene diamine. Diamines can be 0 wt% to 1 wt% of the one or more input streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more input streams. The one or more input streams can be substantially free of alcohols, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, or a combination thereof. Alcohols can be 0 wt% to 1 wt% of the one or more input streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more input streams. In various aspects, other than optional water, optional purge gas, and optional catalyst, the aliphatic dinitrile is 95 wt% to 100 wt% of the one or more input streams, or 100 wt% of the one or more input streams, or less than or equal to 100 wt% and greater than or equal to 95 wt% and less than, equal to, or greater than 95.5 wt%, 96, 96.5, 97, 97.5, 98, 98.5, 99, 99.5, 99.6, 99.7, 99.8, 99.9, or 99.99 wt% of the one or more input streams.INV-23014-WO-PCT

[0062] The apparatus can further include a mixer configured to combine a water stream and one or more C4-C10 aliphatic dinitrile streams to form the one or more reactor input streams that flow to the reaction zone of the reactor via the reactor input flow channel. In various aspects, the mixer can be further configured to combine a filtrate stream and / or higher-boiling constituents stream (which streams are further described below) with the water stream and the one or more C4-C10 aliphatic dinitrile streams to form the one or more reactor input streams. In various aspects, the mixer can be configured to combine a recycled water stream (as further described below) with the water stream and the one or more C4-C10 aliphatic dinitrile streams to form the one or more reactor input streams.

[0063] The one or more output streams can include water. The one or more output streams can include a purge gas, such as a purge gas added to the one or more input streams (e.g., an inert gas, steam, or a combination there), a purge gas generated in the reaction chamber (e.g., steam), or a combination thereof. The one or more output streams can include ammonia generated during the hydrolysis of the aliphatic dinitrile to form the dicarboxylic acid, such as ammonia entrained in one or more purge gases. In aspects wherein a catalyst is included in the one or more input streams, the one or more output streams can include a catalyst. The one or more output streams can include a gaseous output stream that is entirely or predominantly one or more gases, wherein the gaseous output stream includes one or more purge gases and ammonia. The gaseous output steam can flow from the reactor near or at a top of the reactor. The one or more output streams can include a liquid output stream that is entirely or predominantly one or more liquids, wherein the liquid output stream includes the dicarboxylic acid. The one or more output streams can include a combined output stream that is a combination of one or more gases and one or more liquids and that includes the dicarboxylic acid, one or more purge gases, and ammonia.

[0064] The one or more output streams can be the only output streams from the reaction zone. The one or more output streams can be substantially free of catalysts, such as any catalyst described herein. For example, catalysts can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. The one or more output streams can be substantially free of diamines, such as diamines suitable for forming a polyamide by reacting with the dicarboxylic acid, such as C4-C10 diamines, such as hexamethylene diamine. For example, diamines can be 0 wt% to 1INV-23014-WO-PCTwt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. The one or more output streams can be substantially free of polyamides, such as nylon 66. For example, polyamides can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. In various aspects, the one or more output streams can be substantially free of acids other than the dicarboxylic acid. For example, acids other than the dicarboxylic acid can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. In various aspects, the one or more output streams can be substantially free of mineral acids. For example, mineral acids can be 0 wt% to 1 wt% of the one or more output streams, or 0 wt% to 0.1 wt%, or 0 wt% to 0.001 wt%, or less than or equal to 1 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.00001 wt%, 0.00005, 0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, or 0.5 wt% of the one or more output streams. Other than optional water, optional purge gas, optional unreacted aliphatic dinitrile, optional catalyst, and ammonia, the carboxylic acid can be 10 wt% to 100 wt% of the one or more output streams, or 50 wt% to 95 wt%, or less than or equal to 100 wt% or greater than or equal to 10 wt% and less than, equal to, or greater than 15 wt%, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99 wt% of the one or more output streams.

[0065] The apparatus can include one reactor or more than one reactor, such as multiple reactors arranged in series or in parallel. The apparatus can provide any suitable conversion of the aliphatic dinitrile (e.g., a conversion per pass through the one or more reactors), such as a conversion of the aliphatic dinitrile of 10% to 100%, or 90% to 100%, or less than or equal to 100% and greater than or equal to 10% and less than, equal to, or greater than 12%, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, or 99.9%. The apparatus can provide any suitable selectivity of the aliphatic dinitrile to the carboxylic acid, such as a selectivity of 50% to 100%, or 80% to 100%, or less than or equal to 100% and greater than or equal to 50% andINV-23014-WO-PCTless than, equal to, or greater than 52%, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99%. The apparatus can provide any suitable yield of the carboxylic acid from the aliphatic dinitrile, such as a yield of 10% to 100%, or 50% to 95%, or less than or equal to 100% and greater than or equal to 10% and less than, equal to, or greater than 12%, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, or 99.9%.

[0066] The reactor can be any suitable type of reactor that can perform the hydrolysis of the one or more dinitriles to the one or more dicarboxylic acids. The reactor can be any suitable type of gas-liquid-solid contacting device. The reactor can be a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, or the like. In various aspects, the reaction zone of the reactor can be configured to be free of ultrasonic irradiation. The reaction zone can be configured to be free of cavitation.

[0067] The reactor can be configured to subject the one or more input streams to the reaction zone conditions for any reaction duration, such as a reaction duration of 0.01 h to 100 h, 1 h to 10 h, 1 h to 8 h, or less than or equal to 100 h and greater than or equal to 0.01 h and less than, equal to, or greater than 0.05 h, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 h. The reactor can be configured to provide reaction zone conditions that include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions. The reaction zone conditions can include a temperature of greater than or equal to 0 °C to less than or equal to 373 °C, or 220 °C to 300 °C, or less than or equal to 373 °C and greater than or equal to 0 °C and less than, equal to, or greater than 10 °C, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 330, 340, 350, 360, or 370 °C. The reactor can be configured to provide reaction zone conditions that include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions. The reactor can be configured to provide reaction zone conditions that include a pressure of 1 atm to 218 atm, or 30 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 1 atm and less than, equal to, or greater than 5 atm, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115,INV-23014-WO-PCT120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm. The reactor can be configured to maintain the reaction zone conditions at a first pressure, and then maintain the reaction zone conditions at a second pressure. In various aspects, the first pressure can be a higher pressure, and the second subsequent pressure can be a lower pressure. For example, the reaction zone conditions can include a first pressure of 100 atm to 218 atm, or 150 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 100 atm and less than, equal to, or greater than 105 atm, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm, and then a second pressure of 1 atm to 100 atm, 30 atm to 100 atm, or less than or equal to 100 atm and greater than or equal to 30 atm and less than, equal to, or greater than 35 atm, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 atm.

[0068] The apparatus can include a reactor integrated heat exchanger configured for the one or more reactor input flow channels and the one or more reactor output streams to flow therethrough such that the one or more reactor input streams exchange heat with the one or more reactor output streams. The reactor integrated heat exchanger can be any suitable integrated heat exchanger. The reactor integrated heat exchanger can include a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.

[0069] The reactor can include a reactor inlet purge stream conduit configured to allow a purge gas to enter the reaction zone, and wherein the reactor includes a reactor output purge stream conduit configured to allow an ammonia-rich purge stream to exit the reaction zone. The purge gas can sparge the reaction zone to remove / purge / disengage from the reaction zone some or all of the ammonia generated during the hydrolytic conversion of the aliphatic dinitrile to the dicarboxylic acid. The purge gas can be any suitable purge gas. The purge gas can include steam, or the purge gas can be substantially free of steam. The purge gas can be or include an inert gas. The purge gas can be or include nitrogen, argon, helium, CO2, or a combination thereof. The purge gas can be or include nitrogen. In various aspects, steam can be generated from the water in the reaction zone and the steam can function as a purge gas, such as in addition to purge gas added via the reactor inlet purge stream conduit. In various aspects, an inert gas can be added to the reaction zone via the reactor inlet purge stream conduit and no steam is added to the reactor inlet purge stream conduit. In various aspects, the reactor inlet purge stream conduit can be located at or near a bottom or lowerINV-23014-WO-PCTportion of the reaction chamber, and the reactor outlet purge stream conduit can be located at or near a top or upper portion of the reaction chamber. The reactor inlet purge stream conduit can include a tube, nozzle, a porous metal structure, a diffuser, a sparging rod, a sintered metal sparger, a ring sparger, a micro sparger, an in-line sparger, or a combination thereof. In various aspects the apparatus of the present disclosure can provide removal of 50 wt% to 100 wt% of the ammonia generated in the reaction zone, or 80 wt% to 100 wt%, or 95 wt% to 100 wt%, or less than or equal to 100 wt% and greater than or equal to 50 wt% and less than, equal to, or greater than 55 wt%, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.9, or 99.99 wt%. The apparatus can be configured for the purge gas to be added at any suitable rate to the reaction zone, such as a rate of 1-1000 SCCM per 30 g to 60 g (e.g., less than or equal to 60 g and greater than or equal to 30 g and less than, equal to, or greater than 32 g, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 g) of aliphatic dinitrile added to the reaction zone via the one or more input streams, or 300-600 SCCM (standard cubic centimeters per minute) per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams, or less than or equal to 1000 SCCM and greater than or equal to 1 SCCM and less than, equal to, or greater than 2 SCCM, 4, 6, 8, 10, 15, 20, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, or 950 SCCM per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams.

[0070] The apparatus can further include an ammonia recovery column configured to accept the ammonia-rich purge stream and to output an enriched ammonia stream and an ammonia recovery column tail stream.

[0071] The apparatus can include a vacuum distillation unit configured to accept the organic stream and to output a lower-boiling organic constituents stream and a higher-boiling constituents stream. The higher-boiling constituents stream can include unconverted C4-C10 aliphatic dinitrile and optionally other reaction intermediates such as adipamide, cyanovaleramide, cyanovaleric acid, and adipamic acid. In various aspects, the lower-boiling organic constituents stream can include 2-cyanocyclopentilideneimine (CPI). The apparatus can further include a vacuum distillation unit integrated heat exchanger configured for the organic stream and the higher-boiling constituents stream to flow therethrough such that the organic stream exchanges heat with the higher-boiling constituents stream. The vacuum distillation unit integrated heat exchanger can include any suitable integrated heat exchanger. The vacuum distillation unit integrated heat exchanger can include a shell-n-tube heatINV-23014-WO-PCTexchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger. The apparatus can include a higher-boiling constituents flow channel configured to flow the higher-boiling constituents stream to the one or more reactor input flow channels, or to a mixer that provides the one or more reactor input flow streams.

[0072] The apparatus can further include a separator unit configured to accept the one or more reactor output streams including the one or more C4-C10 dicarboxylic acids from the reactor, and configured to output an organic stream and an aqueous stream including the one or more C4-C10 dicarboxylic acids. In various aspects, the separator unit can be a liquidliquid separator unit, such as including a gravity settler, cyclone separator, a decanter, or a combination thereof. In various aspects, the apparatus includes one reactor and not more than one reactor.

[0073] In various aspects, the apparatus can include multiple reactors, such as two reactors. The reactor described above can be a first-stage reactor, and the reaction zone described above can be a first-stage reaction zone in the first-stage reactor. The separator unit can be a solid-liquid separator unit, and the organic stream can be a separated solidified stream. The solid-liquid separator unit can be any suitable solid-liquid separator unit, such as including a vacuum filtration device, a pressure filtration device, centrifuge, gravity separator, decanter, a cyclone separator, or a combination thereof. The apparatus can further include a washing unit configured to wash the separated solidified stream with an aqueous liquid (e.g., water) to form a washed separated solidified stream and used water. The apparatus can further include a second-stage reactor including a second-stage reaction zone, wherein the second-stage reactor is configured to maintain the second-stage reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of aliphatic dinitriles in the washed separated solidified stream to the corresponding one or more C4-C10 dicarboxylic acids, wherein the second-stage reactor is configured to accept the washed separated solidified stream and a second-stage reactor water stream and output a second-stage reactor effluent stream including the one or more C4-C10 dicarboxylic acids.

[0074] The second-stage reactor can be any suitable type of reactor that can perform the hydrolysis of the one or more dinitriles to the one or more dicarboxylic acids. The second-stage reactor can be any suitable type of gas-liquid-solid contacting device. The second-stage reactor can be a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, or the like. InINV-23014-WO-PCTvarious aspects, the second-stage reaction zone of the second-stage reactor can be configured to be free of ultrasonic irradiation. The second-stage reaction zone can be configured to be free of cavitation. The second-stage reactor can be configured to subject the one or more input streams to the second-stage reaction zone conditions for any reaction duration, such as a reaction duration of 0.01 h to 100 h, 1 h to 10 h, 1 h to 8 h, or less than or equal to 100 h and greater than or equal to 0.01 h and less than, equal to, or greater than 0.05 h, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 h. The second-stage reactor can be configured to provide reaction zone conditions that include a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the second-stage reaction zone conditions. The second-stage reaction zone conditions can include a temperature of greater than or equal to 0 °C to less than or equal to 373 °C, or 220 °C to 300 °C, or less than or equal to 373 °C and greater than or equal to 0 °C and less than, equal to, or greater than 10 °C, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 330, 340, 350, 360, or 370 °C. The second-stage reactor can be configured to provide second-stage reaction zone conditions that include a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the second-stage reaction zone conditions. The second-stage reactor can be configured to provide reaction zone conditions that include a pressure of 1 atm to 218 atm, or 30 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 1 atm and less than, equal to, or greater than 5 atm, 10, 15, 20, 25, 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, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm. The second-stage reactor can be configured to maintain the second-stage reaction zone conditions at a first pressure, and then maintain the second-stage reaction zone conditions at a second pressure. In various aspects, the first pressure can be a higher pressure, and the second subsequent pressure can be a lower pressure. For example, the second-stage reaction zone conditions can include a first pressure of 100 atm to 218 atm, or 150 atm to 200 atm, or less than or equal to 218 atm and greater than or equal to 100 atm and less than, equal to, or greater than 105 atm, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, or 215 atm, and then a second pressure of 1 atm to 100 atm, 30 atm to 100 atm, or less than or equalINV-23014-WO-PCTto 100 atm and greater than or equal to 30 atm and less than, equal to, or greater than 35 atm, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 atm.

[0075] An apparatus including the second-stage reactor can further include a second-stage reactor integrated heat exchanger configured for the second-stage reactor water stream and second-stage reactor effluent stream flow to flow therethrough such that the second-stage reactor water stream exchanges heat with the second-stage reactor effluent stream. The second-stage reactor integrated heat exchanger can be any suitable integrated heat exchanger. The second-stage reactor integrated heat exchanger can include a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.

[0076] The second-stage reactor can include a second-stage reactor inlet purge stream conduit configured to allow a second purge gas to enter the second-stage reaction zone, and wherein the second-stage reactor includes a second-stage reactor output purge stream conduit configured to allow a second ammonia-rich purge stream to exit the second-stage reaction zone. The second purge gas can sparge the second-stage reaction zone to remove / purge / disengage from the second-stage reaction zone some or all of the ammonia generated during the hydrolytic conversion of the aliphatic dinitrile to the dicarboxylic acid. The second purge gas can be any suitable purge gas. The second purge gas can be the same or different than the purge gas used in the first-stage reactor. The second purge gas can include steam, or the second purge gas can be substantially free of steam. The second purge gas can be or include an inert gas. The second purge gas can be or include nitrogen, argon, helium, CO2, or a combination thereof. The second purge gas can be or include nitrogen. In various aspects, steam can be generated from the water in the second-stage reaction zone and the steam can function as a second purge gas, such as in addition to second purge gas added via the second-stage reactor inlet purge stream conduit. In various aspects, an inert gas can be added to the second-stage reaction zone via the second-stage reactor inlet purge stream conduit and no steam is added to the second-stage reactor inlet purge stream conduit. In various aspects, the second-stage reactor inlet purge stream conduit can be located at or near a bottom or lower portion of the second-stage reaction chamber, and the second-stage reactor outlet purge stream conduit can be located at or near a top or upper portion of the second-stage reaction chamber. The second-stage reactor inlet purge stream conduit can include a tube, nozzle, a porous metal structure, or a combination thereof. In various aspects the apparatus of the present disclosure can provide removal of 50 wt% to 100 wt% of theINV-23014-WO-PCTammonia generated in the second-stage reaction zone, or 80 wt% to 100 wt%, or 95 wt% to 100 wt%, or less than or equal to 100 wt% and greater than or equal to 50 wt% and less than, equal to, or greater than 55 wt%, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.9, or 99.99 wt%. The apparatus can be configured for the purge gas to be added at any suitable rate to the second-stage reaction zone, such as a rate of 1-1000 SCCM per 30 g to 60 g (e.g., less than or equal to 60 g and greater than or equal to 30 g and less than, equal to, or greater than 32 g, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 g) of aliphatic dinitrile added to the second-stage reaction zone, or 300-600 SCCM (standard cubic centimeters per minute) per 30 g to 60 g of aliphatic dinitrile added to the second-stage reaction zone, or less than or equal to 1000 SCCM and greater than or equal to 1 SCCM and less than, equal to, or greater than 2 SCCM, 4, 6, 8, 10, 15, 20, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, or 950 SCCM per 30 g to 60 g of aliphatic dinitrile added to the second-stage reaction zone.

[0077] The ammonia recovery column can be configured to accept the ammonia-rich purge stream and the second ammonia-rich purge stream and to output the enriched ammonia stream and the ammonia recovery column tail stream.

[0078] The apparatus can include an evaporator unit configured to accept the aqueous stream including the one or more C4-C10 dicarboxylic acids and optionally (for aspects of the apparatus including the second-stage reactor) the second-stage reactor effluent stream of claim 137, and to output water and a concentrated slurry stream including the one or more C4-C10 dicarboxylic acids. The apparatus can include an evaporator unit integrated heat exchanger configured for the aqueous stream and concentrated slurry stream to flow therethrough such that the aqueous stream exchanges heat with the concentrated slurry stream. The evaporator unit integrated heat exchanger can be any suitable integrated heat exchanger. The evaporator unit integrated heat exchanger can include a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.

[0079] The apparatus can include a concentrated slurry stream separation unit configured to accept the concentrated slurry stream and to output a filtrate stream and a solid product stream including the one or more C4-C10 dicarboxylic acids. The concentrated slurry stream separation unit can include a rotary drum separator, centrifuge, decanter, vacuum filtration device, pressure filtration device, or a combination thereof. The apparatus canINV-23014-WO-PCTinclude a filtrate flow channel configured to flow the filtrate to the one or more reactor input channels. The filtrate flow channel can include a purge conduit configured to purge some of the filtrate to control build-up of undesirable reaction byproducts in the apparatus.

[0080] The apparatus can further include a washing unit configured to accept the solid product stream and water, and to output used water and washed solid product stream that includes the one or more C4-C10 dicarboxylic acids. The apparatus can be configured to combine the used water with the aqueous stream from the separator unit including the one or more C4-C10 dicarboxylic acids. The apparatus can further include a drying unit configured to accept the washed solid product stream and to output a dried solid product stream including the one or more C4-C10 dicarboxylic acids.Examples

[0081] Various aspects of the present invention can be better understood by reference to the following Examples which are offered by way of illustration. The present invention is not limited to the Examples given herein.

[0082] Abbreviations. AA: Adipic Acid or 1,6-hexanediacid; ADN: adiponitrile or 1,6-hexanedinitrile; CPE 2-cyanocyclopetylideneimine; CPN: cyclopentanone; GC: gas chromatography; NFLOH: ammonium hydroxide; H3PO4: phosphoric acid; NH4H2PO4: ammonium phosphate monobasic; W / Zr: tungsted zirconia; MAWP: maximum allowable working pressure; SCCM: standard cubic centimeters per minute; DCM: dichloromethane.

[0083] Materials used in the Examples: ADN (INVISTA; CAS 111-69-3; 99.9%); ammonium hydroxide 28-30% (Ward’s Science; CAS 1336-21-6); phosphoric acid (Sigma Aldrich; CAS 7664-382; 85%); ammonium phosphate monobasic (Sigma Aldrich; CAS 7722-76-1; 98%); adipic acid (Ascend Performance Materials Inc.; CAS 124-04-09; 99%); acetone (Sigma Aldrich; 67-64-1; 99.5%); methanol (Sigma Aldrich; CAS 67-56-1; 99.8%); formic acid (Sigma Aldrich; CAS 64-18-6; 98%); suberonitrile (Sigma Aldrich; CAS 629-40-3; 98%); sulfuric acid (Sigma Aldrich; CAS 7664-93-9; 98%); dimethyl adipate (Sigma Aldrich; CAS 627-93-0; 99%); dichloromethane (Thermo Fisher; CAS 513-35-9; 99.8%); water (Sigma Aldrich; CAS 7732-18-5); nitrogen gas (CAS 7727-37-9).Example 1. General procedure for semi-batch experiments in 500 mL reactor.

[0084] All semi-batch tests were performed in a 500 mL Autoclave Engineers autoclave (MAWP 3300 psig (-224.5 atm) at 850 °F (-454 °C)). Before each test, theINV-23014-WO-PCTautoclave was sealed and checked for leaks. Then, it was purged with N2 to remove air and depressurized to atmospheric pressure. The reactor, stirred mechanically, was heated externally using an argon-purged electric furnace and cooled internally with water through a cooling coil.

[0085] High-pressure N2 was produced from a standard 800 psig (~54 atm) N2 gas cylinder using a MaxPro Technologies gas booster (Model DLE75-2-UU-M) to compress it to 8400 psig (-571.5 atm). This compressed gas was then stored in a 2-liter high-pressure N2 reservoir (Autoclave Engineers Self-sealing Closure Vessel rated at MAWP 10,500 psig (-715 atm) at 72 °F (-22 °C)). The compressor automatically shuts off when the reservoir pressure reaches 8400 psig (-571.5 atm). High-pressure nitrogen was introduced into the autoclave at the desired flow rate by adjusting a needle valve. The flow rate of nitrogen was monitored using a mass-flow meter. The autoclave was operated at a constant pressure, which can be regulated either by a back pressure regulator or a control valve connected to the headspace of the autoclave.

[0086] For a typical experiment, the necessary amounts of water, ADN, and catalyst (if applicable) were placed into a 1 -liter reactants transfer vessel. The contents were subsequently introduced into the autoclave at ambient temperature through an autoclave port, utilizing nitrogen pressure on the vapor space of the reactants transfer vessel. The total volume of reactants in the autoclave was maintained below 75% of its capacity under operating conditions. The reactor was then stirred, heated to the specified temperature, and pressurized with high-pressure N2 at targeted pressure. Samples of the reaction mixture were collected from the reactor using a sampling dip-tube at predetermined intervals (ranging from 1 to 6 h). The liquid samples were collected at autoclave temperature and then cooled to room temperature before being transferred to a sample vial.

[0087] Gas chromatography (GC) analysis. Samples were analyzed by GC (Agilent 7890 series instrument), equipped with flame ionization detector (FID), and a DB-624 UI Agilent column (30 m length, 0.32 mm diameter). Hydrogen was used as the GC carrier gas and as the FID makeup gas. The analysis conditions were: split ratio = 20: 1, injector temperature = 250 °C, detector temperature = 300 °C, carrier gas flow rate = 1.8 mL / min. The temperature program: start at 65 °C, increase by 9 °C / min to 150 °C, then increase by 9.3 °C / min to 250 °C, and hold for 10 min. A 0.2 wt% solution of suberonitrile in methanol was used as an internal standard for GC. Calibration standards such as ADN, cyclopentanone, adipamide, adipic acid, and CPI were prepared in a mixture of methanol and water (1:1)INV-23014-WO-PCTsolution. Calibration standards and reaction mixture samples were analyzed using GC by combining them with a suberonitrile internal standard solution and a premixed solution of formic acid and methanol (1:1).

[0088] For mono- and dimethyl adipate calibration, dichloromethane (DCM) was used as the solvent for sample preparation. Another GC method was also used to quantify acid such as adipic acid from the esterification method. The reaction mixture containing acid was treated with 10 wt% sulfuric acid / methanol solution at 120 °C for 5 minutes. The esterified solution was diluted with water and then extracted with DCM three times. The DCM phases were combined, analyzed by GC, and acid was quantified.

[0089] ADN conversion was calculated by dividing the moles of reacted reactant by initial moles, then converting to a percentage. Product selectivity was determined by dividing the moles of the desired product by the total moles of all products.

[0090] For tests where CO2 is used as a catalyst, the reactants are transferred to the reactants transfer vessel without the catalyst. The autoclave is then pressurized from atmospheric pressure using CO2 gas by opening the CO2 gas cylinder line connected to the top of the autoclave. After the CO2 gas pressurization is completed, the CO2 inlet valve at the top of the autoclave is closed. While aspects of the present disclosure are not limited by any particular chemical mechanism, theoretically, the CO2 may facilitate the in-situ generation of H2CO3, serving as a catalyst for hydrolysis with potentially improved catalytic activity. An additional theoretical benefit could be the capture of generated ammonia, allowing for the straightforward separation of NH3 and CO2. These reactions are illustrated in Scheme 1 below.

[0091] Scheme 1. Use of CO2 during hydrolysis of adiponitrile.<&AA + Int. Products + H2OExamples la-ld. 5 wt% ADN in feed; 260 °C; 1200 psig (-81,6 atm); no inert gas purge.INV-23014-WO-PCT

[0092] Following the general procedure outlined in Example 1, a reaction mixture including 5 wt% ADN (13.9 g) in water (265.0 g) was heated at 260 °C under a constant pressure of 1200 psig (-81.6 atm), without performing a nitrogen gas purge. Table 1 illustrates the dinitrile conversion and the selectivity for individual species.

[0093] Table 1. 5 wt% ADN in feed; 260 °C; 1200 psig; no inert gas purge.* In Table 1 and all subsequent tables, percentage conversion = (moles of dinitrile reacted) / (initial moles of dinitrile fed) x 100, and percentage selectivity of individual species = (moles of the product) / (total moles of all products) x 100.Examples 2a-21, Effect of Reaction Pressure.

[0094] Following the general procedure outlined in Example 1, a reaction mixture including 10 wt% ADN (27.8 g) in water (250.6 g) was heated at 260 °C under a constant pressure of 700 psig (-47.6 atm) and 2500 psig (-170.1 atm), without performing a nitrogen gas purge. Table 2 illustrates the dinitrile conversion and the selectivity for individual species.

[0095] Table 2. 10 wt% ADN in feed; 260 °C; no inert gas purge.

[0096] In the absence of inert gas purge the reaction pressure influences the conversion of adiponitrile and adipic acid selectivity. At 700 psig (-47.6 atm) pressure operation, higher than 90% adiponitrile conversion is achieved in about 5 hours of run-time along with the adipic acid selectivity approaching past 80%. At 2500 psig (-170.1 atm)INV-23014-WO-PCTpressure, the adiponitrile conversion of 90%+ is achieved in a short run-time of 2 hours. However, the adipic acid selectivity reaches a plateau in the low-50s %.Examples 3a-3p, Effect of ammonia removal by gas purge.

[0097] Following the general procedure outlined in Example 1, a reaction mixture including 10 wt% ADN (27.8 g) in water (250.6 g) was heated at 260 °C under a constant pressure of 2500 psig (-170.1 atm), with varying N2 gas purge rate (35, 800, and 900 SCCM). Table 3 illustrates the dinitrile conversion and the selectivity for individual species.

[0098] Table 3. 10 wt% ADN in feed; 260 °C; 2500 psig (-170.1 atm).*sccm - cc / min at standard conditions (15.6 °C & 1 atm);

[0099] The reaction pressure shows no notable impact on adiponitrile conversion to adipic acid selectivity when the inert gas flow was turned on. The Table 3 data can be compared with Examples 5a-5f of Table 5, wherein all reaction conditions were kept the same under the inert gas purge except for the reaction pressure.Examples 4a-41, Effect of reaction pressure in combination with ammonia removal by gas purge.

[0100] Following the general procedure outlined in Example 1, a reaction mixture including 10 wt% ADN (27.8 g) in water (250.6 g) was heated at 260 °C under pressure of 1200 psig (-81.6 atm) and 1500 psig (-102 atm), with N2 gas purge rates of 400 and 515 SCCM. Table 4 illustrates the dinitrile conversion and the selectivity for individual species.INV-23014-WO-PCT

[0101] Table 4. 10 wt% ADN in feed; 260 °C.*sccm - cc / min at standard conditions (15.6 °C & 1 atm);Examples 5a-5n: Effect of reaction temperature.

[0102] Using the general procedure from Example 1, a mixture of 10 wt% ADN in water was heated at 260, 280, and 295 °C under 1200 psig (-81.6 atm) pressure with a 400 SCCM N2 gas purge. Table 5 illustrates the dinitrile conversion and the selectivity for individual species.

[0103] Table 5. 10 wt% ADN in feed; 1200 psig (-81.6 atm); 400 std. cc / min N2 flow.

[0104] The temperature increase may achieve higher adiponitrile conversion in a short run-time. However, the adipic acid degradation to cyclopentanone tends to increase as the reaction temperature is increased.INV-23014-WO-PCTExamples 6a-6o, Effect of dinitrile feed concentration.

[0105] Using the general procedure from Example 1, ADN mixtures (10, 15, and 20 wt%) in water was heated at 260 °C under 1200 psig (-81.6 atm) pressure with a 400 SCCM N2 gas purge. Table 6 illustrates the dinitrile conversion and the selectivity for individual species.

[0106] Table 6. 260 °C; 1200 psig (-81.6 atm); 400 std.cc / minN2 flow.Example 7, General procedure for batch experiments in 35 mL reactor.

[0107] All batch tests were conducted in a 20- or 35-mL closed Swagelok tubular reactor. Before each test, the reactor was cleaned three times with water and methanol, then dried overnight in an oven.

[0108] For a typical experiment, the required quantities of water, ADN, and catalyst (if applicable) were placed into a 20 or 35-mL Swagelok tubular reactor equipped with a Teflon-coated magnetic stir bar. Following the addition, the tubes were sealed with a cap containing a pressure gauge and valve, and then placed in an aluminum heating block. The reactor was stirred and heated to the specified temperature for the designated time, allowing autogenous pressure to develop based on the vapor pressure of water at the reaction temperature. After the reaction was completed, the reactor was allowed to cool to room temperature. The reaction sample was then analyzed by GC following the analytical procedure outlined in Example 1. The conversion of ADN and product selectivity were calculated according to the general procedure outlined in Example 1.INV-23014-WO-PCTExamples 7a-7b: Effect of Reaction Pressure.

[0109] Following the general procedure outlined in Example 7, a reaction mixture including 5 wt% ADN in water was heated at 262 °C under an autogenous water pressure (700 psig (-47.6 atm) for Example 7a; 2500 psig (-170.1 atm) initially, decreasing to 1100 psig (-74.8 atm) after 6 hours for Example 7b), without performing a nitrogen gas purge. Table 7 illustrates the dinitrile conversion and the selectivity for individual species.

[0110] Table 7. 5 wt% ADN in feed; 262 °C.Examples 8a-8c. Effect of Reaction Temperature.

[0111] Following the general procedure outlined in Example 7, a mixture of 5 wt% ADN in water was heated at 254, 262, and 270 °C under an autogenous water pressure (initially 2500 psig (-170.1 atm), decreasing to 1300 psig (-88.4 atm), 1100 psig (-74.8 atm), and 750 psig (-51 atm) after 6 hours for Examples 8a, 8b, and 8c), without a nitrogen gas purge. Table 8 illustrates the dinitrile conversion and the selectivity for individual species.

[0112] Table 8. 5 wt% ADN in feed; 262 °C.Examples 9a-9d. Effect of dinitrile feed concentration.

[0113] Following the general procedure outlined in Example 7, ADN mixtures (5, 10, 20, and 40 wt%) in water was heated at 256 °C under an autogenous water pressure. The initial pressure was 2500 psig (-170.1 atm), which decreased over 6 hours to 1300 psig (-88.4 atm) for Example 9a, and to 500 psig (-34 atm) for Examples 9b, 9c, and 9d. This procedure was conducted without a nitrogen gas purge. Table 9 illustrates the dinitrile conversion and the selectivity for individual species.INV-23014-WO-PCT

[0114] Table 9. Effect of dinitrile feed concentration.Example 10: Subsequent hydrolysis of intermediate products from the first step

[0115] The reaction effluent, as obtained from Example 9c, was recovered from the system. The effluent was allowed to cool down to about 30°C. Some of the reaction product and intermediates solidified while the rest stayed dissolved in the effluent liquid. The solidified portion was isolated from the liquid effluent by filtration and subsequently washed with water. The separated solids were further hydrolyzed to afford additional adipic acid from the intermediates and precursors to adipic acid. The subsequent hydrolysis was performed at 255 °C, 600 Psig pressure and for about 1.5 hours run-time in the absence of inert gas purge.

[0116] Table 10 tabulates the dinitrile conversion and the selectivity for individual species, and provides a summary of the subsequent hydrolysis performance. The recovered solid portion composition from Example 9c effluent was (in wt.%) about 55.4% adipamide, 38.9% adipic acid, 4.9% cyanovaleroamide, balance being CPN and CPI.

[0117] Table 10. 255 °C; 600 psig (-40.8 atm); 1.5 h; without N2 flow.

[0118] The product obtained from the subsequent hydrolysis contained 98.2 wt% adipic acid, 1.6 wt% cyanovaleramide and 0.1 wt% CPN. The adipamide present in the feed was completely hydrolyzed into the final product, adipic acid.INV-23014-WO-PCTExamples 1 la-1 Id. Effect of catalyst.

[0119] Following the general procedure outlined in Example 7, ADN mixture (5, 9, or 11 wt% in water) and stoichiometric amount of a catalyst (NH4OH, H3PO4, NH4H2PO4) relative to ADN (i.e., 1 : 1 molar ratio of catalyst relative to ADN) were heated at 290°C under an autogenous water pressure (800 psig) for 6 hr without nitrogen gas purge. Table 11 illustrates the dinitrile conversion and the selectivity for individual species.

[0120] Table 11. 10 mL reaction mixture charged in the reactor; 290 °C, 800 psig (-55.4 atm).Examples 12a-12c. Using tungstated zirconia catalyst.

[0121] Following the general procedure outlined in Example 7, ADN mixture (5, 10, and 20 wt%) in water and 1 wt% tungstated zirconia catalyst was heated at 256°C under an autogenous water pressure. The initial pressure of 2500 psig (-170.1 atm) gradually decreased over 6 hours to 900 psig (-61.2 atm) for Example 12a, and to 500 psig (-34 atm) for Examples 12b and 12c. This procedure was conducted without a nitrogen gas purge. Table 12 illustrates the dinitrile conversion and the selectivity for individual species.

[0122] Table 12. 1 wt% W / Zr catalyst; wt% ADN in feed; 256 °C, 6 h.Example 13, Global Warming Potential (GWP) equivalency improvement for the disclosed process.INV-23014-WO-PCT

[0123] A preliminary assessment of the environmental (e.g., greenhouse gas emissions) impact of adipic acid manufacture by the disclosed process versus a conventional Ce feedstock-nitric acid oxidation method is performed. Cyclohexane is typically used as Ce feedstock for adipic acid manufacture.

[0124] In the first step of analysis below, it is assumed that adipic acid is manufactured from cyclohexane via the conventional nitric acid oxidation route. Much of the adipic acid produced in the world is manufactured by processes that first convert cyclohexane feedstock either to cyclohexanol (A), or to a cyclohexanone (K) and cyclohexanol (A) mixture (known as KA oil). In a subsequent series of process steps, refined KA oil is oxidized with nitric acid to produce adipic acid, which is then purified by crystallization.

[0125] A technical article titled “Adipic Acid Industry - N2O Abatement”, authored by Reimer et al., and published in Non-CCh Greenhouse Gases: Scientific Understanding, Control and Implementation, 347-358 (2000) Kluwer Academic Publishers provides some useful information regarding the offgas N2O emissions per unit of adipic acid produced. About 0.3 units of nitrous oxide (N2O) per unit of adipic acid has been estimated in this publication.

[0126] In industrial adipic acid production, the relevant Global Warming Potential (GWP) value is typically associated with the nitrous oxide (N2O) emitted as a byproduct. It is known from the above reference that N2O has a GWP of around 290 times that of carbon dioxide (CO2) over a 100-year horizon. This means that the emission of one mass unit of N2O from adipic acid production is equivalent to (e.g., CChe) about 290 mass units of CO2 emitted to the environment. The environmental impact potency of N2O in the industry is a well-recognized fact.

[0127] Upon offgas N2O abatement, GWP impact reduction can be realized depending on the N2O abatement efficiency as illustrated in Table 13.

[0128] Table 13. GWP impact reduction upon offgas N2O abatement.*A commercially available database, Sphera (2023.1), reports a value of PCF for adipic acid for U.S production from cyclohexane as 6.42 kg CO2 equivalent per kg adipic acid. This is based on IPCC AR6GWP 100 (including biogenic CO2) for adipic acid produced from cyclohexane in the U.S. This value is reported for the overall process with N2O abatement with an abatement efficiency between 80 to 98%.INV-23014-WO-PCT

[0129] The term “N2O abatement”, as used herein, refers to a post-process step wherein the N2O present in the adipic acid plant offgas undergoes chemical decomposition into N2 and O2.

[0130] The term “N2O abatement efficiency”, as used herein, refers to an efficiency at which N2O destruction is achieved in the offgas treatment step. A 95% N2O abatement efficiency means about 95% of the incoming N2O is destructed in this post-process step. A 100% N2O abatement efficiency means the complete destruction of N2O present in the incoming offgas. The unabated adipic acid manufacture means the offgas N2O has not been destructed at all, for which the N2O Abatement Efficiency is 0%.

[0131] In the second step of analysis below, it is assumed that adipic acid is manufactured according to the disclosed process, i.e., by adiponitrile hydrolysis route. This process eliminates the cyclohexane feedstock, nitric acid oxidation and the resulting N2O emissions in the offgas.

[0132] The synthesis step, according to the disclosed process, can be represented as follows: (1 mole) adiponitrile + (4 moles) H2O -> (1 mole) adipic acid + (2 moles) NH3. Using this molar stoichiometry with conversions and selectivities observed in the examples detailed above, about 1 kg (6.845 moles; 146.1 MW) of adipic acid production would require about 0.9 kgs (8.1 moles; 108.1 MW) of adiponitrile to hydrolyze with about 0.6 kgs (32.5 moles; 18 MW) of water, and about 0.5 kgs (27 moles; 17 MW) of ammonia. The liberated ammonia from the hydrolysis reaction may be recovered, purified and may find uses in other synthesis steps.

[0133] The GWP equivalency for adiponitrile manufacture from a conventional butadiene hydrocyanation process is “Y” kgs CChe / kg adiponitrile produced. For illustration purposes, “Y” is a numerical value and can be 0.1 or 0.5 or 1 or 1.5 or 5 or 10 or 25 or 35 or 50, etc. The order-of-magnitude impact may be illustrated in the multiples of “Y”. Table 14 estimates the GWP (SCOPE1; 100-YR) equivalency of adiponitrile, process water, ammonia, and adipic acid.INV-23014-WO-PCT

[0134] Table 14. GWP (SCOPE1; 100-YR) of various materials.

[0135] The dinitrile feedstock needed in the disclosed process, adiponitrile, may be produced by various chemical or bio-chemical routes. Examples are double hydrocyanation of butadiene with a cyanide source, electro-dimerization coupling of acrylonitrile, and the like. The GWP equivalency for adiponitrile produced may, therefore, vary depending on the synthesis process used.

[0136] For example, when Y is between 1 and 5, the GWP equivalency for the disclosed process may be estimated to be between 1.1 and 4.8 kg CChe per kg of adipic acid using Table 14. In another example, when Y is 4.5 the GWP equivalency for the disclosed process may be estimated to be between 3.81 and 4.42 kg CChe per kg of adipic acid using the Table 14. Further, an upside in further reduction may be realized by 2.658 kg CChe per kg ammonia when the ammonia by-product credit can be applied.

[0137] Upon comparison of the two estimates for GWP equivalency of kg CChe per kg of adipic acid produced, it is observed that the disclosed process of making adipic acid from adiponitrile hydrolysis affords a GWP Equivalency (kg CChe per kg product) reduction. It is observed that the disclosed adipic acid production from adiponitrile hydrolysis may improve the product carbon footprint (PCF) per each kg of adipic acid produced. The reduction in GWP impact is unexpectedly observed via the above comparison.Example 14, An apparatus for the method of making a dicarboxylic acid.

[0138] FIG. l is a schematic representation of a method of making a dicarboxylic acid, and as described in any of Examples 1-9 and Examples 11-12.

[0139] In FIG. 1, dinitrile make-up and water streams, represented by streams 101 and 102, respectively, are pumped in and mixed with a recycled organic-rich stream 115 and recycled water stream 123. The streams may either be introduced separately or pre-mixed, for example, in a mixer unit Ml . The mixer unit Ml may be an inline mixer, a mixing-tee, aINV-23014-WO-PCTstatic mixer, or a combination of such. The resulting mixed feed stream 103 is a two-phase liquid stream and is preheated by heat exchanger unit 1010. The heat exchanger unit 1010 may be heat-integrated with a reactor effluent stream cooler unit 1040, which is schematically represented by the dotted line HX1.

[0140] The term “heat-integrated”, as used throughout this disclosure, means that the heat is exchanged (therefore, heat-integrated) in the same unit wherein one stream heats (or cools) the other stream according to the temperature ranges of the two streams. The heatintegration may use a device such as a shell-n-tube heat exchanger, annular, double pipe or pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, coils-in-shell heat exchanger, and such. Those skilled in the art of heat exchangers appreciate such heat integration processes and equipment for improving the process carbon footprint via efficient heat utilization.

[0141] The preheated feed stream 104 exiting the heat-exchanger unit 1010 enters a reactor unit 1020 which provides sufficient residence time for the hydrolysis of dinitrile to its corresponding dicarboxylic acid product and other intermediates.

[0142] The reactor unit 1020 may be any suitable type of a gas-liquid-solid contacting device, such as a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, and the like.

[0143] A purge gas stream 105 is fed to the reactor unit 1020 for continuously purging the reactor contents. The dinitrile hydrolysis may evolve gaseous ammonia-containing constituents as undesirable by-products. The continuous purge may be effective to concurrently disengage these gaseous byproducts out of the reaction mixture while the hydrolysis reaction is progressing. The purge gas stream 105 may be an inert material. Nonlimiting examples may include nitrogen, argon, helium, steam, CO2, and mixtures thereof. The skilled may choose a suitable purge gas based on the availability and production cost.

[0144] The reactor unit 1020 may be operated at temperatures ranging from ambient to 400°C and at pressures ranging from ambient to 3,000 psig (-204 atm). The purge gas discharge stream 106 exiting the reactor unit 1020 contains mostly ammonia. This ammonia-rich purge gas discharge stream 106 may be fed to an ammonia recovery column 1030. The ammonia recovery column 1030 may be operated at such temperatures and pressures to obtain an enriched ammonia stream 107 from the top of the ammonia recovery column 1030. The enriched ammonia stream 107 may be further processed for ammonia recovery and reuse. The column tails stream 108 may be mostly water with other by-products generatedINV-23014-WO-PCTduring the hydrolysis reaction and may be further processed or disposed via proper posttreatment.

[0145] The exiting reactor effluent stream 109 may be fed to the cooler unit 1040 and cooled to a suitable temperature to obtain a cooled product stream 110. The cooled product stream 110 may be de-pressurized and separated into an aqueous stream 116 and an organic stream 111 in a liquid-liquid separator unit 1050. The liquid-liquid separator unit 1050 may be any suitable device such as a gravity settler, cyclone separator, decanter, and the like. Either a single unit or multiple stages may be utilized depending on the desired separation quality.

[0146] The separated organic stream 111 may be preheated by heat-integration in a preheater unit 1060. The preheated organic stream 112 may be fed to a vacuum distillation unit 1070 to concentrate and separate a lighter (lower-boiling) organic constituents stream 113 from a heavier (higher-boiling) constituents stream 114. One embodiment of the adiponitrile hydrolysis to adipic acid method may produce the lighter organic constituents stream 113 containing 2-cyanocyclopentilideneimine (CPI). The remaining unconverted adiponitrile and other reaction intermediates, such as adipamide, cyanovaleramide, cyanovaleric acid, and adipamic acid may be concentrated in the heavier constituents stream 114 and separated at the column 1070 bottom. In one embodiment, the preheater unit 1060 may be heat-integrated with a column bottom cooler 1080, which is schematically represented by the dotted line HX2. The heavier constituents stream 114 temperature may be suitably reduced in the cooler 1080 and the cooled stream 115 may be recycled back to the mixer unit Ml for another hydrolysis reaction pass for product yield improvement.

[0147] The aqueous stream 116 may be pre-heated in a heat exchanger unit 1090 to a suitable temperature range to obtain a product stream 117 and fed to an evaporator unit 1100. The excess water from the product stream 117 may be removed as a water-rich stream 118. A concentrated slurry stream 119 containing the desired dicarboxylic acid product, obtained from the evaporator unit 1100, may be cooled in a heat exchanger unit 1110. In one embodiment, the heat exchanger units 1090 and 1110 may be heat-integrated as schematically represented by the dotted line HX3.

[0148] Upon cooling that leads to crystallization of the super-saturated constituents, and mostly, the desired dicarboxylic acid product, the concentrated slurry stream 120 exiting the heat exchanger unit 1110 may contain the dicarboxylic acid product crystals of desired purity and yield. The concentrated slurry cooling and crystallization steps may be performedINV-23014-WO-PCTeither in a single unit or multiple units, and in any series and parallel configuration. The cooled and crystal -laden concentrated slurry stream 120 may further undergo crystal separation from rest of the material in a suitable separation unit 1120. The separation unit 1120 may be a rotary drum separator, centrifuge, decanter, vacuum filtration, pressure filtration, and the like.

[0149] The remaining filtrate stream 121, exiting the separation unit 1120, may be suitable for recycle and reuse in the hydrolysis reaction step. A small purge stream 122 may be taken to control and minimize the build-up of any undesirable reaction byproducts in the overall process. The remaining filtrate stream 123 may be recycled back to the mixer unit Ml to serve as a liquid medium during the hydrolysis reaction step.

[0150] The solid product stream 124, obtained from the separation unit 1120, may be a wet product cake, which may be washed / rinsed with a chilled water stream 125 in a second separation unit 1130 to further remove trapped impurities from the solid product. The washed / rinsed solids product stream 127, obtained from the unit 1130, may be fed to a drying unit 1140 to reduce the moisture content. A dried solid product stream 128 may be obtained having the desired properties and purity. In the case of adiponitrile hydrolysis, the dried solid product is adipic acid. In the case of glutaronitrile hydrolysis, the dried solid product is glutaric acid.

[0151] The spent wash / rinse stream 126, exiting from the unit 1130 and containing mostly water, may be recycled back to the evaporator unit 1100 via the heat exchanger 1090. The spent wash / rinse stream 126 may be mixed and diluted with the aqueous stream 116 before heating in the heat exchanger unit 1090.

[0152] In one embodiment of the disclosed method, adiponitrile undergoes hydrolysis in the presence of water, and the solid product is adipic acid. In another embodiment, glutaronitrile undergoes hydrolysis in the presence of water, and the solid product is glutaric acid. In yet another embodiment, 2-methylglutaronitrile undergoes hydrolysis in the presence of water, and the solid product is 2-methylglutaric acid.

[0153] Thus, this example, illustrated by FIG. 1, discloses a method of making a dicarboxylic acid from a dinitrile and the apparatus effective for obtaining the dicarboxylic acid according to the disclosed method.Example 15, An apparatus for the method of making a dicarboxylic acid.INV-23014-WO-PCT

[0154] FIG. 2 is a schematic representation of a method of making a dicarboxylic acid, and as described in Example 10.

[0155] The apparatus described in this example and FIG. 2 is another embodiment of the disclosed method, wherein the hydrolysis is performed in two stages. A dinitrile feed is hydrolyzed in the first stage, and upon separation, the partially hydrolyzed intermediate components formed in the first stage are further hydrolyzed in the second stage. It is observed that this approach further improves the overall product yield.

[0156] In FIG. 2, a dinitrile make-up and water streams, represented by streams 201 and 202, respectively, are pumped in and mixed with a recycled water stream 223. The streams may either be introduced separately or pre-mixed, for example, in a mixer unit M21. The mixer unit M21 may be an inline mixer, a mixing-tee, a static mixer, or a combination of such. The resulting mixed feed stream 203 is a two-phase liquid stream and is preheated by a heat exchanger unit 2010. The heat exchanger unit 2010 may be heat-integrated with a reactor effluent stream cooler unit 2040, which is schematically represented by the dotted line HX21. The preheated feed stream 204 exiting the heat-exchanger unit 2010 enters a first-stage reactor unit 2020 which provides sufficient residence time for the hydrolysis of dinitrile to its corresponding dicarboxylic acid product and other intermediates.

[0157] The first-stage reactor unit 2020 may be any suitable type of a gas-liquid-solid contacting device, such as a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, and the like.

[0158] A first-stage purge gas stream 205 is fed to the first-stage reactor unit 2020 for continuously purging the reactor contents. The dinitrile hydrolysis may evolve gaseous ammonia-containing constituents as undesirable by-products. The continuous purge may be effective to concurrently disengage these gaseous byproducts out of the reaction mixture while the hydrolysis reaction is progressing. The first-stage purge gas stream 205 may be an inert material. Non-limiting examples may include nitrogen, argon, helium, steam, CO2, and mixtures thereof. The skilled may choose a suitable first-stage purge gas based on the availability and production cost.

[0159] The first-stage reactor unit 2020 may be operated at temperatures ranging from ambient to 400°C and at pressures ranging from ambient to 3,000 psig (-204 atm). The first-stage purge gas discharge stream 206 exiting the first-stage reactor unit 2020 contains mostly ammonia. This ammonia-rich first-stage purge gas discharge stream 206 may be fed to an ammonia recovery column 2030. The ammonia recovery column 2030 may be operatedINV-23014-WO-PCTat such temperatures and pressures to obtain an enriched ammonia stream 207 from the top of the ammonia recovery column 2030. The enriched ammonia stream 207 may be further processed for ammonia recovery and re-use. The column tails stream 208 may be mostly water with other by-products generated during the hydrolysis reaction and may be further processed or disposed via proper post-treatment.

[0160] The exiting first-stage reactor effluent stream 209 may contain the desired dicarboxylic acid product from complete dinitrile hydrolysis as well as such partially converted components as cyclo-imines, cyclo-ketones, diamides, cyano-amides, cyano-acids, and the like. For example, in the case of adiponitrile hydrolysis, the first-stage reactor effluent stream 209 may contain adipic acid as well as adipamide, cyanovaleramide, cyanovaleric acid, adipamic acid, 2-cyanocyclopentilideneimine (CPI), and cyclopentanone along with some unconverted adiponitrile and water.

[0161] The stream 209 may undergo substantial cooling in a cooler unit 2040 and form a cooled first-stage reactor effluent stream 210. Depending on the individual component concentrations and solubilities, some portion of the stream 210 may solidify and some portion may remain as a liquid. The partially solidified stream 210 may be fed to a solid-liquid separation unit 2050 that is effective in separating the solidified portion from the liquid portion. The unit 2050 may be any suitable device such as vacuum filtration, pressure filtration, centrifuge, gravity separator, decanter, cyclone separation, or combinations thereof.

[0162] The separated solidified stream 211 may be washed / rinsed with additional water stream 212 to remove any fugitive impurities from the solids and filtered in a unit 2060 to obtain a filtrate stream 213. The washed solids stream 214 is fed to a second-stage reactor unit 2150 with an additional preheated water stream 229 to further hydrolyze the first-step reactor intermediates to the desired product. Adequate amount of a fresh water stream 215 may be preheated in a unit 2070 to provide the preheated water stream 229.

[0163] A second-stage purge gas stream 230 is fed to the second-stage reactor unit 2150 for continuously purging the reactor contents. The hydrolysis reaction may evolve gaseous ammonia-containing constituents as undesirable by-products. The continuous purge may be effective to concurrently disengage these gaseous byproducts out of the reaction mixture while the hydrolysis reaction is progressing. The second-stage purge gas stream 230 may be an inert material. Non-limiting examples may include nitrogen, argon, helium, steam, CO2, and mixtures thereof. The skilled may choose a suitable second-stage purge gas based on the availability and production cost.INV-23014-WO-PCT

[0164] The second-stage reactor unit 2150 may be any suitable type of a gas-liquid-solid contacting device, such as a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, etc.

[0165] The second-stage reactor unit 2150 may be operated at temperatures ranging from ambient to 400°C and at pressures ranging from ambient to 3,000 psig (-204 atm). The second-stage purge gas discharge stream 233 exiting the second-stage reactor unit 2150 contains mostly ammonia. This ammonia-rich second-stage purge gas discharge stream 233 may either be mixed (not shown) with the first-stage purge gas discharge stream 206 and fed to the ammonia recovery column 2030 or may be independently fed (as shown) to the column 2030.

[0166] The exiting second-stage reactor effluent stream 231 may mostly contain the desired dicarboxylic acid product along with some unconverted intermediates and excess water. For example, the second-stage reactor effluent stream 231 may contain adipic acid, trace levels of adipamide, cyanovaleramide, cyanovaleric acid, adipamic acid, 2-cyanocyclopentilideneimine (CPI), cyclopentanone and excess water.

[0167] The stream 231 may undergo substantial temperature reduction to a cooled stream 232 in a cooler unit 2080 and the cooled stream 232 may be joined with an aqueous stream 216 obtained from the solid separator unit 2050. Additional aqueous streams, namely, 213 and 226 may also be combined with the stream 216. The combined aqueous streams may be pre-heated in a heat exchanger unit 2090 to a suitable temperature range to obtain a product stream 217 and fed to an evaporator unit 2100. The excess water from the product stream 217 may be removed as a water-rich stream 218. A concentrated slurry stream 219 containing the desired dicarboxylic acid product, obtained from the evaporator unit 2100, may be cooled in a heat exchanger unit 2110.

[0168] Upon cooling that leads to crystallization of the super-saturated constituents, and mostly, the desired dicarboxylic acid product, the concentrated slurry stream 220, exiting the heat exchanger unit 2110, may contain the dicarboxylic acid product crystals of desired purity and yield. The concentrated slurry cooling and crystallization steps may be performed either in a single unit or multiple units, and in any series and parallel configuration. The cooled and crystal-laden concentrated slurry stream 220 may further undergo crystal separation from rest of the material in a suitable separation unit 2120. The separation unit 2120 may be a rotary drum separator, centrifuge, decanter, vacuum filtration, pressure filtration, and the like.INV-23014-WO-PCT

[0169] The remaining filtrate stream 221, exiting the separation unit 2120, may be suitable for recycle and reuse in the hydrolysis reaction step. A small purge stream 222 may be taken to control and minimize a build-up of any undesirable reaction byproducts in the overall process. The recycled water stream 223 may be recycled back to the mixer unit M21 to serve as liquid medium during the first-stage hydrolysis reaction step.

[0170] The solid product stream 224, obtained from the separation unit 2120, may be a wet product cake, which may be washed / rinsed with a chilled water stream 225 in a second separation unit 2130 to further remove trapped impurities from the solid product. The washed / rinsed solids product stream 227, obtained from the unit 2130, may be fed to a drying unit 2140 to reduce the moisture content. A dried solid product stream 228 may be obtained having the desired properties and purity. In the case of adiponitrile hydrolysis, the dried solid product is adipic acid. In the case of glutaronitrile hydrolysis, the dried solid product is glutaric acid.

[0171] The spent wash / rinse stream 226, exiting from the unit 2130 and containing mostly water, may be recycled back to the evaporator unit 2100 via the heat exchanger 2090. The spent wash / rinse stream 226 may be mixed and diluted with other aqueous streams 216, 213 and 232, as schematically shown in FIG. 2, before heating in the heat exchanger unit 2090.

[0172] In one embodiment, the heat exchanger units 2070 and 2080 may be heat-integrated and schematically represented by the dotted line HX22. Similarly, the heat exchanger units 2090 and 2110 may be heat-integrated and schematically represented by the dotted line HX23.

[0173] In one embodiment of the disclosed method and as illustrated in Example 10, the first-stage reactor effluent stream 209 was recovered from Example 9c. Example 9c performed the first-stage hydrolysis step using adiponitrile and water feeds. The effluent stream 209 was cooled down to about 30 °C via the cooler unit 2040. Some of the first-stage reaction product and intermediates solidified while the rest stayed dissolved in the effluent liquid. The solidified portion represented by 211 was isolated from the liquid effluent by filtration in unit 2050 and subsequently washed with water stream 212. The separated solids stream 214 was further hydrolyzed in the second-stage reactor unit 2150 to afford additional adipic acid from the intermediates and precursors to adipic acid.

[0174] The first-stage hydrolysis step of Example 9c was performed at 254°C, 2500 psig (-170.1 atm) (initial) to 500 psig (-34 atm) (final) pressure and for about 6 hours run-INV-23014-WO-PCTtime in the absence of inert gas purge stream. The second-stage hydrolysis step was performed at 255 °C, 600 psig (-40.8 atm) pressure and for about 1.5 hours run-time in the absence of inert gas purge stream.

[0175] As previously shown in Tables 9 and 10, the first-stage hydrolysis reactor was fed with about 20% adiponitrile in water, and produced an effluent (such as stream 209 of FIG. 2) containing the organic portion of (wt.%) about 66.2% adipic acid, 12.9% adipamide, 9.4% cyanovareric acid, 4.0% adipamic acid, 3.8% cyanovaleramide, 3% CPI and 0.7% CPN. The adiponitrile conversion in the first-stage hydrolysis reactor was about 97.6%.

[0176] The disclosed process scheme of FIG. 2 was followed for the first-stage reactor effluent stream 209 via the units 2040, 2050 and 2060. The recovered solids portion (such as stream 214 of FIG. 2) composition was (in wt.%) about 55.4% adipamide, 38.9% adipic acid, 4.9% cyanovaleroamide, and traces of cyanovaleric acid, adipamic acid, CPN and CPI. The recovered solids portion was further hydrolyzed in the second-stage hydrolysis step.

[0177] The second-stage hydrolysis product stream (such as stream 231 upon solids separation) contained about 98.2 wt% adipic acid, 1.6 wt% cyanovaleramide and 0.1 wt% CPN. The adipamide present in the second-stage reactor feed was completely hydrolyzed into the final product, adipic acid.

[0178] Thus, this example and FIG. 2 illustrate the disclosed method of making a dicarboxylic acid from a dinitrile and the apparatus effective for further improving the dicarboxylic acid.

[0179] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the aspects of the present invention. Thus, it should be understood that although the present invention has been specifically disclosed by specific aspects and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of aspects of the present invention.Exemplary Aspects.INV-23014-WO-PCT

[0180] The following exemplary aspects are provided, the numbering of which is not to be construed as designating levels of importance:

[0181] Aspect 1 provides a method of making a dicarboxylic acid comprising:flowing one or more input streams comprising one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor, the reaction zone comprising water;maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions; andflowing one or more output streams comprising the one or more C4-C10 dicarboxylic acids from the reactor.

[0182] Aspect 2 provides the method of Aspect 1, wherein the reaction zone is free of ultrasonic irradiation.

[0183] Aspect 3 provides the method of any one of Aspects 1-2, wherein the one or more input streams comprise water.

[0184] Aspect 4 provides the method of any one of Aspects 1-3, wherein the one or more input streams comprise a purge gas, wherein the purge gas removes ammonia from the reaction zone.

[0185] Aspect 5 provides the method of Aspect 4, wherein the purge gas comprises steam.

[0186] Aspect 6 provides the method of Aspect 4, wherein the purge gas comprises an inert gas.

[0187] Aspect 7 provides the method of any one of Aspects 5-6, wherein the inert gas comprises nitrogen, argon, helium, CO2, or a combination thereof.

[0188] Aspect 8 provides the method of any one of Aspects 5-7, wherein the inert gas is nitrogen.

[0189] Aspect 9 provides the method of any one of Aspects 4-8, wherein the purge gas is added to the reaction zone at a rate of 1-1000 SCCM per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams.INV-23014-WO-PCT

[0190] Aspect 10 provides the method of any one of Aspects 4-9, wherein the purge gas is added to the reaction zone at a rate of 300-600 SCCM per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams.

[0191] Aspect 11 provides the method of any one of Aspects 4-10, wherein the one or more input streams comprise a gaseous input stream comprising the purge gas.

[0192] Aspect 12 provides the method of Aspect 11, comprising adding the purge gas to the reaction zone via a tube, nozzle, a porous metal structure, a diffuser, a sparging rod, a sintered metal sparger, a ring sparger, a micro sparger, an in-line sparger, or a combination thereof.

[0193] Aspect 13 provides the method of any one of Aspects 4-12, wherein the one or more input streams comprise a combined input stream comprising the purge gas and the aliphatic dinitrile.

[0194] Aspect 14 provides the method of any one of Aspects 1-13, wherein the one or more input streams comprise a liquid input stream comprising the aliphatic dinitrile.

[0195] Aspect 15 provides the method of any one of Aspects 1-14, wherein the one or more input streams comprise a catalyst.

[0196] Aspect 16 provides the method of Aspect 15, wherein the catalyst comprises an acid catalyst.

[0197] Aspect 17 provides the method of Aspect 16, wherein the acid catalyst comprises a mineral acid, an organic acid, or a combination thereof.

[0198] Aspect 18 provides the method of any one of Aspects 16-17, wherein the acid catalyst comprises sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, perchloric acid, citric acid, acetic acid, formic acid, lactic acid, malic acid, tartaric acid, oxalic acid, or a combination thereof.

[0199] Aspect 19 provides the method of any one of Aspects 16-18, wherein the acid catalyst comprises NH4H2PO4, H3PO4, or a combination thereof.

[0200] Aspect 20 provides the method of any one of Aspects 15-19, wherein the catalyst comprises a basic catalyst.

[0201] Aspect 21 provides the method of Aspect 20, wherein the basic catalyst comprises potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, ammonium phosphate, ammonium hydroxide, sodium hydroxide, or a combination thereof.INV-23014-WO-PCT

[0202] Aspect 22 provides the method of any one of Aspects 20-21, wherein the basic catalyst comprises NH4OH.

[0203] Aspect 23 provides the method of any one of Aspects 15-22, wherein the catalyst comprises CO2, tungstated zirconia (W / Zr), zeolite Y, zeolite Beta, Zeolite MFI, ammonium phosphate, ammonium bicarbonate ((NH3)HCO3), ammonium carbonate ((NH3)2CO3), or a combination thereof.

[0204] Aspect 24 provides the method of any one of Aspects 15-23, wherein the catalyst is present in the one or more input streams in an amount that is 0.001 wt% to 30 wt% based on the amount of aliphatic dinitrile in the one or more input streams.

[0205] Aspect 25 provides the method of any one of Aspects 15-24, wherein the catalyst is present in the one or more input streams in an amount that is 0.1 wt% to 5 wt% based on the amount of aliphatic dinitrile in the one or more input streams.

[0206] Aspect 26 provides the method of any one of Aspects 1-25, wherein the one or more input streams are the only input streams to the reaction zone.

[0207] Aspect 27 provides the method of Aspect 26, wherein the one or more input streams are substantially free of catalysts.

[0208] Aspect 28 provides the method of any one of Aspects 26-27, wherein catalysts are 0 wt% to 0.1 wt% of the one or more input streams.

[0209] Aspect 29 provides the method of any one of Aspects 26-28, wherein catalysts are 0 wt% to 0.001 wt% of the one or more input streams.

[0210] Aspect 30 provides the method of any one of Aspects 26-29, wherein the one or more input streams are substantially free of diamines.

[0211] Aspect 31 provides the method of any one of Aspects 26-30, wherein diamines are 0 wt% to 0.1 wt% of the one or more input streams.

[0212] Aspect 32 provides the method of any one of Aspects 26-31, wherein diamines are 0 wt% to 0.001 wt% of the one or more input streams.

[0213] Aspect 33 provides the method of any one of Aspects 26-32, wherein other than optional water, optional purge gas, and optional catalyst, the aliphatic dinitrile is 95 wt% to 100 wt% of the one or more input streams.

[0214] Aspect 34 provides the method of any one of Aspects 26-33, wherein other than optional water, optional purge gas, and optional catalyst, the aliphatic dinitrile is 100 wt% of the one or more input streams.INV-23014-WO-PCT

[0215] Aspect 35 provides the method of any one of Aspects 1-34, wherein the one or more output streams comprise water.

[0216] Aspect 36 provides the method of any one of Aspects 1-35, wherein the one or more output streams comprise a purge gas.

[0217] Aspect 37 provides the method of any one of Aspects 1-36, wherein the one or more output streams comprise ammonia.

[0218] Aspect 38 provides the method of any one of Aspects 1-37, wherein the one or more output streams comprise a catalyst.

[0219] Aspect 39 provides the method of any one of Aspects 1-38, wherein the one or more output streams comprise a gaseous output stream comprising a purge gas and ammonia.

[0220] Aspect 40 provides the method of Aspect 39, wherein the gaseous output stream flows from the reactor near or at a top of the reactor.

[0221] Aspect 41 provides the method of any one of Aspects 1-40, wherein the one or more output streams comprise a liquid output stream comprising the dicarboxylic acid.

[0222] Aspect 42 provides the method of any one of Aspects 1-41, wherein the one or more output streams comprise a combined output stream comprising the dicarboxylic acid, a purge gas, and ammonia.

[0223] Aspect 43 provides the method of any one of Aspects 1-42, wherein the one or more output streams are the only output streams from the reaction zone.

[0224] Aspect 44 provides the method of Aspect 43, wherein the one or more output streams are substantially free of catalysts.

[0225] Aspect 45 provides the method of any one of Aspects 43-44, wherein catalysts are 0 wt% to 0.1 wt% of the one or more output streams.

[0226] Aspect 46 provides the method of any one of Aspects 43-45, wherein catalysts are 0 wt% to 0.001 wt% of the one or more output streams.

[0227] Aspect 47 provides the method of any one of Aspects 43-46, wherein the one or more output streams are substantially free of diamines.

[0228] Aspect 48 provides the method of any one of Aspects 43-47, wherein the one or more output streams are substantially free of polyamides.

[0229] Aspect 49 provides the method of any one of Aspects 43-48, wherein other than optional water, optional purge gas, optional unreacted aliphatic dinitrile, optional catalyst, and ammonia, the carboxylic acid is 10 wt% to 100 wt% of the one or more output streams.INV-23014-WO-PCT

[0230] Aspect 50 provides the method of any one of Aspects 43-49, wherein other than optional water, optional purge gas, optional unreacted aliphatic dinitrile, optional catalyst, and ammonia, the carboxylic acid is 50 wt% to 95 wt% of the one or more output streams.

[0231] Aspect 51 provides the method of any one of Aspects 1-50, wherein the one or more input streams comprise a concentration of the aliphatic dinitrile in water of 0.1 wt% to 50 wt%.

[0232] Aspect 52 provides the method of any one of Aspects 1-51, wherein the one or more input streams comprise a concentration of the aliphatic dinitrile in water of 1 wt% to 30 wt%.

[0233] Aspect 53 provides the method of any one of Aspects 1-52, comprising a conversion of the aliphatic dinitrile of 10% to 100%.

[0234] Aspect 54 provides the method of any one of Aspects 1-53, comprising a conversion of the aliphatic dinitrile of 90% to 100%.

[0235] Aspect 55 provides the method of any one of Aspects 1-54, comprising a selectivity of the aliphatic dinitrile to the carboxylic acid of 50% to 100%.

[0236] Aspect 56 provides the method of any one of Aspects 1-55, comprising a selectivity of the aliphatic dinitrile to the carboxylic acid of 80% to 100%.

[0237] Aspect 57 provides the method of any one of Aspects 1-56, comprising a yield of the carboxylic acid from the aliphatic dinitrile of 10% to 100%.

[0238] Aspect 58 provides the method of any one of Aspects 1-57, comprising a yield of the carboxylic acid from the aliphatic dinitrile of 50% to 95%.

[0239] Aspect 59 provides the method of any one of Aspects 1-58, comprising maintaining the reaction zone conditions for a reaction duration of 0.01 h to 100 h.

[0240] Aspect 60 provides the method of any one of Aspects 1-59, comprising maintaining the reaction zone conditions for a reaction duration of 1 h to 10 h.

[0241] Aspect 61 provides the method of any one of Aspects 1-60, wherein the reaction zone conditions comprise a temperature of greater than or equal to 0 °C to less than or equal to 373 °C.

[0242] Aspect 62 provides the method of any one of Aspects 1-61, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C.

[0243] Aspect 63 provides the method of any one of Aspects 1-62, wherein the reaction zone conditions comprise a pressure of 1 atm to 218 atm.INV-23014-WO-PCT

[0244] Aspect 64 provides the method of any one of Aspects 1-63, wherein the reaction zone conditions comprise a pressure of 30 atm to 200 atm.

[0245] Aspect 65 provides the method of any one of Aspects 1-64, wherein the reaction zone conditions comprise a first pressure of 100 atm to 218 atm and then a second pressure of 1 atm to 100 atm.

[0246] Aspect 66 provides the method of any one of Aspects 1-65, wherein the reaction zone conditions comprise a first pressure of 150 atm to 200 atm and then a second pressure of 30 atm to 100 atm.

[0247] Aspect 67 provides the method of any one of Aspects 1-66, further comprising agitating materials in the reaction zone.

[0248] Aspect 68 provides the method of any one of Aspects 1-67, wherein the aliphatic dinitrile is succinonitrile, glutaronitrile, adiponitrile, 2-methylglutaronitrile, or 2-ethylsuccinonitrile.

[0249] Aspect 69 provides the method of any one of Aspects 1-68, wherein the aliphatic dinitrile is or is derived from purified dinitrile obtained from a fossil-fuel feedstock conversion process, purified dinitrile obtained from a biological feedstock conversion process, semi-refined dinitrile, crude dinitrile, diluted aqueous dinitrile stream, by-product dinitrile, a waste dinitrile stream, or a combination thereof.

[0250] Aspect 70 provides the method of any one of Aspects 1-69, wherein the dicarboxylic acid is succinic acid, glutaric acid, adipic acid, 2-methylglutaric acid, or 2-ethylsuccinic acid.

[0251] Aspect 71 provides the method of any one of Aspects 1-70, wherein the aliphatic dinitrile is adiponitrile and the dicarboxylic acid is adipic acid.

[0252] Aspect 72 provides the method of Aspect 71, wherein the one or more output streams further comprise cyanovaleramide, cyanovaleric acid, adipamide, adipamic acid, 2-cyanocyclopetylideneimine, cyclopentanone, or a combination thereof.

[0253] Aspect 73 provides the method of any one of Aspects 1-72, wherein the method is a continuous process for making the dicarboxylic acid.

[0254] Aspect 74 provides the method of any one of Aspects 1-73, wherein the method is a batch or semi-batch process for making the dicarboxylic acid.

[0255] Aspect 75 provides the method of any one of Aspects 1-74, wherein the reactor comprises an autoclave, a column, a tubular reactor, a tank reactor, a plug flowINV-23014-WO-PCTreactor, a packed bed reactor, a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, or a bubble column reactor.

[0256] Aspect 76 provides the method of any one of Aspects 1-75, further comprising recovering the one or more C4-C10 dicarboxylic acids from the reaction zone and / or from the one or more output streams.

[0257] Aspect 77 provides the method of Aspect 76, wherein recovering the one or more C4-C10 dicarboxylic acids comprises distillative separation, evaporative separation, wiped-film evaporation, short-path distillation, solvent extraction, cryogenic separation, crystallization, filtration, membrane separation, or a combination thereof.

[0258] Aspect 78 provides the method of any one of Aspects 76-77, wherein recovering the one or more C4-C10 dicarboxylic acids comprises rotary drum separation, centrifugation, decantation, vacuum filtration, pressure filtration, aqueously washing the one or more C4-C10 dicarboxylic acids, drying the one or more C4-C10 dicarboxylic acids, or a combination thereof.

[0259] Aspect 79 provides the method of any one of Aspects 1-78, wherein the method has a Global Warming Potential (GWP) Equivalency, determined in terms of kg CO2 equivalents per kg of the formed dicarboxylic acid, that is 0.1% to 99% of that of a process of making the same dicarboxylic acid product by a hydrocarbon feedstock oxidation.

[0260] Aspect 80 provides the method of any one of Aspects 1-79, wherein the method has a Global Warming Potential (GWP) Equivalency, determined in terms of kg CO2 equivalents per kg of the formed dicarboxylic acid, that is 0.1% to 10% of that of a process of making the same dicarboxylic acid product by a hydrocarbon feedstock oxidation.

[0261] Aspect 81 provides the method of any one of Aspects 1-80, wherein the reactor is a first-stage reactor and the reaction zone is a first-stage reaction zone, wherein the one or more output streams comprise unreacted dinitriles in addition to the one or more C4-C10 dicarboxylic acids, further comprising separating the unreacted dinitriles and the one or more C4-C10 dicarboxylic acids to form an organic stream comprising the unreacted dinitriles and an aqueous stream comprising the one or more C4-C10 dicarboxylic acids, flowing the organic stream to a second-stage reaction zone of a second-stage reactor, the second-stage reaction zone comprising water, maintaining conditions of the second-stage reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the second-stage reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercriticalINV-23014-WO-PCTtemperature of water under the second-stage reaction zone conditions, and the second-stage reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the second-stage reaction zone conditions, and flowing one or more second output streams comprising the one or more C4-C10 dicarboxylic acids from the second-stage reactor.

[0262] Aspect 82 provides the method of Aspect 81, further comprising combining the one or more second output streams comprising the one or more C4-C10 dicarboxylic acids from the second-stage reactor and the aqueous stream comprising the one or more C4-C10 dicarboxylic acids to form a product stream.

[0263] Aspect 83 provides the method of Aspect 82, further comprising recovering the one or more C4-C10 dicarboxylic acids from the product stream.

[0264] Aspect 84 provides the method of Aspect 83, wherein recovering the one or more C4-C10 dicarboxylic acids comprises rotary drum separation, centrifugation, decantation, vacuum filtration, pressure filtration, aqueously washing the one or more C4-C10 dicarboxylic acids, drying the one or more C4-C10 dicarboxylic acids, or a combination thereof.

[0265] Aspect 85 provides a method of making adipic acid comprising:flowing one or more input streams comprising adiponitrile to a reaction zone of a reactor, the reaction zone comprising water, wherein the one or more input streams are the only input streams to the reaction zone and wherein the one or more input streams are substantially free of catalysts;maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the adiponitrile to adipic acid, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm; andflowing one or more output streams comprising the adipic acid from the reactor. Aspect 86 provides a method of making adipic acid comprising:flowing one or more input streams comprising adiponitrile to a reaction zone of a reactor, the reaction zone comprising water, wherein the one or more input streams comprise a purge gas that is an inert gas;maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the adiponitrile to adipic acid, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm; andINV-23014-WO-PCTflowing one or more output streams comprising the adipic acid from the reactor, wherein the one or more output streams comprise the purge gas and ammonia.

[0266] Aspect 87 provides an apparatus for making a dicarboxylic acid comprising:one or more reactor input flow channels configured to flow one or more reactor input streams comprising one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor; the reactor comprising the reaction zone, wherein the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions; andone or more reactor output flow channels configured to flow one or more reactor output streams comprising the one or more C4-C10 dicarboxylic acids from the reactor.

[0267] Aspect 88 provides the apparatus of Aspect 87, wherein the aliphatic dinitrile is succinonitrile, glutaronitrile, adiponitrile, 2-methylglutaronitrile, or 2-ethylsuccinonitrile.

[0268] Aspect 89 provides the apparatus of any one of Aspects 87-88, wherein the dicarboxylic acid is succinic acid, glutaric acid, adipic acid, 2-methylglutaric acid, or 2-ethylsuccinic acid.

[0269] Aspect 90 provides the apparatus of any one of Aspects 87-89, wherein the aliphatic dinitrile is adiponitrile and the dicarboxylic acid is adipic acid.

[0270] Aspect 91 provides the apparatus of Aspect 90, wherein the one or more output streams further comprise cyanovaleramide, cyanovaleric acid, adipamide, adipamic acid, 2-cyanocyclopetylideneimine, cyclopentanone, or a combination thereof.

[0271] Aspect 92 provides the apparatus of any one of Aspects 87-90, wherein the one or more input streams comprise a catalyst.

[0272] Aspect 93 provides the apparatus of Aspect 92, wherein the catalyst comprises an acid catalyst.

[0273] Aspect 94 provides the apparatus of any one of Aspects 92-93, wherein the catalyst comprises a basic catalyst.

[0274] Aspect 95 provides the apparatus of any one of Aspects 92-94, wherein the catalyst comprises CO2, phosphoric acid, tungstated zirconia (W / Zr), zeolite Y, zeolite Beta,INV-23014-WO-PCTZeolite MFI, ammonium phosphate, ammonium bicarbonate ((NH3)HCO3), ammonium carbonate ((NEb^CCh), or a combination thereof.

[0275] Aspect 96 provides the apparatus of any one of Aspects 92-95, wherein the catalyst is present in the one or more input streams in an amount that is 0.001 wt% to 30 wt% based on the amount of aliphatic dinitrile in the one or more input streams.

[0276] Aspect 97 provides the apparatus of any one of Aspects 92-96, wherein the catalyst is present in the one or more input streams in an amount that is 0.1 wt% to 5 wt% based on the amount of aliphatic dinitrile in the one or more input streams.

[0277] Aspect 98 provides the apparatus of any one of Aspects 87-97, wherein the one or more input streams are the only input streams to the reaction zone.

[0278] Aspect 99 provides the apparatus of Aspect 98, wherein the one or more input streams are substantially free of catalysts.

[0279] Aspect 100 provides the apparatus of any one of Aspects 98-99, wherein the one or more input streams are substantially free of diamines.

[0280] Aspect 101 provides the apparatus of any one of Aspects 98-100, wherein other than optional water, optional purge gas, and optional catalyst, the aliphatic dinitrile is 95 wt% to 100 wt% of the one or more input streams.

[0281] Aspect 102 provides the apparatus of any one of Aspects 87-101, wherein the one or more output streams are the only output streams from the reaction zone.

[0282] Aspect 103 provides the apparatus of Aspect 102, wherein the one or more output streams are substantially free of catalysts.

[0283] Aspect 104 provides the apparatus of any one of Aspects 102-103, wherein the one or more output streams are substantially free of diamines.

[0284] Aspect 105 provides the apparatus of any one of Aspects 102-104, wherein the one or more output streams are substantially free of polyamides.

[0285] Aspect 106 provides the apparatus of any one of Aspects 102-105, wherein other than optional water, optional purge gas, optional unreacted aliphatic dinitrile, optional catalyst, and ammonia, the carboxylic acid is 10 wt% to 100 wt% of the one or more output streams.

[0286] Aspect 107 provides the apparatus of any one of Aspects 87-106, wherein the one or more input streams comprise a concentration of the aliphatic dinitrile in water of 0.1 wt% to 50 wt%.INV-23014-WO-PCT

[0287] Aspect 108 provides the apparatus of any one of Aspects 87-107, comprising a conversion of the aliphatic dinitrile of 10% to 100%.

[0288] Aspect 109 provides the apparatus of any one of Aspects 87-108, comprising a selectivity of the aliphatic dinitrile to the carboxylic acid of 50% to 100%.

[0289] Aspect 110 provides the apparatus of any one of Aspects 87-109, comprising a yield of the carboxylic acid from the aliphatic dinitrile of 10% to 100%.

[0290] Aspect 111 provides the apparatus of any one of Aspects 87-110, wherein the reactor is any suitable type of a gas-liquid-solid contacting device, such as a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, or the like.

[0291] Aspect 112 provides the apparatus of any one of Aspects 87-111, wherein the reaction zone is free of ultrasonic irradiation.

[0292] Aspect 113 provides the apparatus of any one of Aspects 87-112, wherein the reactor is configured to subject the one or more input streams to the reaction zone conditions for a reaction duration of 0.01 h to 100 h.

[0293] Aspect 114 provides the apparatus of any one of Aspects 87-113, wherein the reactor is configured to subject the one or more input streams to the reaction zone conditions for a reaction duration of 1 h to 10 h.

[0294] Aspect 115 provides the apparatus of any one of Aspects 87-114, wherein the reaction zone conditions comprise a temperature of greater than or equal to 0 °C to less than or equal to 373 °C.

[0295] Aspect 116 provides the apparatus of any one of Aspects 87-115, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C.

[0296] Aspect 117 provides the apparatus of any one of Aspects 87-116, wherein the reaction zone conditions comprise a pressure of 1 atm to 218 atm.

[0297] Aspect 118 provides the apparatus of any one of Aspects 87-117, wherein the reaction zone conditions comprise a pressure of 30 atm to 200 atm.

[0298] Aspect 119 provides the apparatus of any one of Aspects 87-118, wherein the reaction zone conditions comprise a first pressure of 100 atm to 218 atm and then a second pressure of 1 atm to 100 atm.

[0299] Aspect 120 provides the apparatus of any one of Aspects 87-119, wherein the reaction zone conditions comprise a first pressure of 150 atm to 200 atm and then a second pressure of 30 atm to 100 atm.INV-23014-WO-PCT

[0300] Aspect 121 provides the apparatus of any one of Aspects 87-120, further comprising a reactor integrated heat exchanger configured for the one or more reactor input flow channels and the one or more reactor output streams to flow therethrough such that the one or more reactor input streams exchange heat with the one or more reactor output streams.

[0301] Aspect 122 provides the apparatus of Aspect 121, wherein the reactor integrated heat exchanger comprises a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.

[0302] Aspect 123 provides the apparatus of any one of Aspects 87-122, further comprising a mixer configured to combine a water stream and one or more one or more C4-C10 aliphatic dinitrile streams to form the reactor input stream that flows to the reaction zone of the reactor via the reactor input flow channel.

[0303] Aspect 124 provides the apparatus of Aspect 123, wherein the mixer is further configured to combine a filtrate stream and / or higher-boiling constituents stream with the water stream and the one or more C4-C10 aliphatic dinitrile streams to form the reactor input stream.

[0304] Aspect 125 provides the apparatus of any one of Aspects 123-124, wherein the mixer is further configured to combine a recycled water stream with the water stream and the one or more C4-C10 aliphatic dinitrile streams to form the reactor input stream.

[0305] Aspect 126 provides the apparatus of any one of Aspects 87-125, wherein the reactor comprises a reactor inlet purge stream conduit configured to allow a purge gas to enter the reaction zone, and wherein the reactor comprises a reactor output purge stream conduit configured to allow an ammonia-rich purge stream to exit the reaction zone.

[0306] Aspect 127 provides the apparatus of Aspect 126, wherein the reactor inlet purge stream conduit comprises a tube, nozzle, a porous metal structure, a diffuser, a sparging rod, a sintered metal sparger, a ring sparger, a micro sparger, an in-line sparger, or a combination thereof.

[0307] Aspect 128 provides the apparatus of any one of Aspects 126-127, wherein the purge gas comprises steam, nitrogen, argon, helium, CO2, or a combination thereof.

[0308] Aspect 129 provides the apparatus of any one of Aspects 126-128, wherein apparatus is configured for the purge gas to be added to the reaction zone at a rate of 1-1000 SCCM per 30 g to 60 g of aliphatic dinitrile added to the reaction zone via the one or more input streams.INV-23014-WO-PCT

[0309] Aspect 130 provides the apparatus of any one of Aspects 126-129, further comprising an ammonia recovery column configured to accept the ammonia-rich purge stream and to output an enriched ammonia stream and an ammonia recovery column tail stream.

[0310] Aspect 131 provides the apparatus of any one of Aspects 87-130, further comprising a separator unit configured to accept the one or more reactor output streams comprising the one or more C4-C10 dicarboxylic acids from the reactor, and configured to output an organic stream and an aqueous stream comprising the one or more C4-C10 dicarboxylic acids.

[0311] Aspect 132 provides the apparatus of Aspect 131, wherein the separator unit is a liquid-liquid separator unit.

[0312] Aspect 133 provides the apparatus of Aspect 132, wherein the liquid-liquid separator unit comprises a gravity settler, cyclone separator, a decanter, or a combination thereof.

[0313] Aspect 134 provides the apparatus of Aspect 131, wherein the reactor is a first-stage reactor and the reaction zone is a first-stage reaction zone, wherein the separator unit is a solid-liquid separator unit, and wherein the organic stream is a separated solidified stream.

[0314] Aspect 135 provides the apparatus of Aspect 134, wherein the solid-liquid separator unit is a vacuum filtration device, a pressure filtration device, centrifuge, gravity separator, decanter, a cyclone separator, or a combination thereof.

[0315] Aspect 136 provides the apparatus of any one of Aspects 134-135, further comprising a washing unit configured to wash the separated solidified stream with water to form a washed separated solidified stream and used water.

[0316] Aspect 137 provides the apparatus of any one of Aspects 134-135, further comprising a second-stage reactor comprising a second-stage reaction zone, wherein the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of aliphatic dinitriles in the washed separated solidified stream to the corresponding one or more C4-C10 dicarboxylic acids, wherein the second-stage reactor is configured to accept the washed separated solidified stream and a second-stage reactor water stream and output a second-stage reactor effluent stream comprising the one or more C4-C10 dicarboxylic acids.INV-23014-WO-PCT

[0317] Aspect 138 provides the apparatus of Aspect 137, wherein the reactor is any suitable type of a gas-liquid-solid contacting device, such as a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, bubble column reactor, or the like.

[0318] Aspect 139 provides the apparatus of any one of Aspects 137-138, further comprising a second-stage reactor integrated heat exchanger configured for the second-stage reactor water stream and second-stage reactor effluent stream flow to flow therethrough such that the second-stage reactor water stream exchanges heat with the second-stage reactor effluent stream.

[0319] Aspect 140 provides the apparatus of Aspect 139, wherein the second-stage reactor integrated heat exchanger comprises a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.

[0320] Aspect 141 provides the apparatus of any one of Aspects 137-140, wherein the second-stage reactor comprises any suitable type of gas-liquid-solid contacting device, such as a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, or a bubble column reactor.

[0321] Aspect 142 provides the apparatus of any one of Aspects 137-141, wherein the second-stage reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the second-stage reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the second-stage reaction zone conditions

[0322] Aspect 143 provides the apparatus of any one of Aspects 137-142, wherein the second-stage reaction zone is free of ultrasonic irradiation.

[0323] Aspect 144 provides the apparatus of any one of Aspects 137-143, wherein the second-stage reactor is configured to subject the one or more input streams to the reaction zone conditions for a reaction duration of 0.01 h to 100 h.

[0324] Aspect 145 provides the apparatus of any one of Aspects 137-144, wherein the second-stage reactor is configured to subject the one or more input streams to the reaction zone conditions for a reaction duration of 1 h to 10 h.INV-23014-WO-PCT

[0325] Aspect 146 provides the apparatus of any one of Aspects 137-145, wherein the second-stage reaction zone conditions comprise a temperature of greater than or equal to 0 °C to less than or equal to 373 °C.

[0326] Aspect 147 provides the apparatus of any one of Aspects 137-146, wherein the second-stage reaction zone conditions comprise a temperature of 220 °C to 300 °C.

[0327] Aspect 148 provides the apparatus of any one of Aspects 137-147, wherein the second-stage reaction zone conditions comprise a pressure of 1 atm to 218 atm.

[0328] Aspect 149 provides the apparatus of any one of Aspects 137-148, wherein the second-stage reaction zone conditions comprise a pressure of 30 atm to 200 atm.

[0329] Aspect 150 provides the apparatus of any one of Aspects 137-149, wherein the second-stage reaction zone conditions comprise a first pressure of 100 atm to 218 atm and then a second pressure of 1 atm to 100 atm.

[0330] Aspect 151 provides the apparatus of any one of Aspects 137-150, wherein the second-stage reaction zone conditions comprise a first pressure of 150 atm to 200 atm and then a second pressure of 30 atm to 100 atm.

[0331] Aspect 152 provides the apparatus of any one of Aspects 137-151, wherein the second-stage reactor comprises a second-stage reactor inlet purge stream conduit configured to allow a second purge gas to enter the second-stage reaction zone, and wherein the second-stage reactor comprises a second-stage reactor output purge stream conduit configured to allow a second ammonia-rich purge stream to exit the second-stage reaction zone.

[0332] Aspect 153 provides the apparatus of Aspect 152, wherein the second-stage reactor inlet purge stream conduit comprises a tube, nozzle, a porous metal structure, a diffuser, a sparging rod, a sintered metal sparger, a ring sparger, a micro sparger, an in-line sparger, or a combination thereof.

[0333] Aspect 154 provides the apparatus of any one of Aspects 152-153, wherein the second purge gas comprises steam, nitrogen, argon, helium, CO2, or a combination thereof.

[0334] Aspect 155 provides the apparatus of any one of Aspects 152-154, wherein apparatus is configured for the second purge gas to be added to the second-stage reaction zone at a rate of 1-1000 SCCM per 30 g to 60 g of aliphatic dinitrile added to the second-stage reaction zone.

[0335] Aspect 156 provides the apparatus of any one of Aspects 130-155, wherein the ammonia recovery column is configured to accept the ammonia-rich purge stream and theINV-23014-WO-PCTsecond ammonia-rich purge stream and to output the enriched ammonia stream and the ammonia recovery column tail stream.

[0336] Aspect 157 provides the apparatus of any one of Aspects 131-156, further comprising a vacuum distillation unit configured to accept the organic stream and to output a lower-boiling organic constituents stream and a higher-boiling constituents stream.

[0337] Aspect 158 provides the apparatus of Aspect 157, wherein the higher-boiling constituents stream comprises unconverted C4-C10 aliphatic dinitrile and optionally other reaction intermediates.

[0338] Aspect 159 The apparatus of any one of Aspects 157-158, further comprising a vacuum distillation unit integrated heat exchanger configured for the organic stream and the higher-boiling constituents stream to flow therethrough such that the organic stream exchanges heat with the higher-boiling constituents stream.

[0339] Aspect 160 provides the apparatus of Aspect 159, wherein the vacuum distillation unit integrated heat exchanger comprises a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.

[0340] Aspect 161 provides the apparatus of any one of Aspects 157-160, further comprising a higher-boiling constituents flow channel configured to flow the higher-boiling constituents stream to the one or more reactor input flow channels.

[0341] Aspect 162 provides the apparatus of any one of Aspects 131-161, further comprising an evaporator unit configured to accept the aqueous stream comprising the one or more C4-C10 dicarboxylic acids and optionally the second-stage reactor effluent stream of any one of Aspects 137-161, and to output water and a concentrated slurry stream comprising the one or more C4-C10 dicarboxylic acids.

[0342] Aspect 163 provides the apparatus of Aspect 162, further comprising an evaporator unit integrated heat exchanger configured for the aqueous stream and concentrated slurry stream to flow therethrough such that the aqueous stream exchanges heat with the concentrated slurry stream.

[0343] Aspect 164 provides the apparatus of Aspect 163, wherein the evaporator integrated heat exchanger comprises a shell-n-tube heat exchanger, annular heat exchanger, double pipe heat exchanger, pipe-in-pipe heat exchanger, plate-n-frame heat exchanger, finned-surface heat exchanger, or a coils-in-shell heat exchanger.INV-23014-WO-PCT

[0344] Aspect 165 provides the apparatus of any one of Aspects 162-164, further comprising a concentrated slurry stream separation unit configured to accept the concentrated slurry stream and to output a filtrate stream and a solid product stream comprising the one or more C4-C10 dicarboxylic acids.

[0345] Aspect 166 provides the apparatus of Aspect 165, wherein the concentrated slurry stream separation unit comprises a rotary drum separator, centrifuge, decanter, vacuum filtration device, pressure filtration device, or a combination thereof.

[0346] Aspect 167 provides the apparatus of any one of Aspects 165-166, further comprising a filtrate flow channel configured to flow the filtrate to the one or more reactor input channels.

[0347] Aspect 168 provides the apparatus of Aspect 167, wherein the filtrate flow channel comprises a purge conduit configured to purge some of the filtrate to control build-up of undesirable reaction byproducts in the apparatus.

[0348] Aspect 169 provides the apparatus of any one of Aspects 165-168, further comprising a washing unit configured to accept the solid product stream and water, and to output used water and washed solid product stream that comprises the one or more C4-C10 dicarboxylic acids.

[0349] Aspect 170 provides the apparatus of Aspect 169, wherein the apparatus is configured to combine the used water with the aqueous stream from the separator unit comprising the one or more C4-C10 dicarboxylic acids.

[0350] Aspect 171 provides the apparatus of any one of Aspects 169-170, further comprising a drying unit configured to accept the washed solid product stream and to output a dried solid product stream comprising the one or more C4-C10 dicarboxylic acids.

[0351] Aspect 172 provides an apparatus for making adipic acid comprising:one or more input flow channels configured to flow one or more input streams comprising adiponitrile to a reaction zone of a reactor, wherein the one or more input streams are the only input streams to the reaction zone and wherein the one or more input streams are substantially free of catalysts;the reactor comprising the reaction zone, wherein the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of adiponitrile to adipic acid, wherein the reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditionsINV-23014-WO-PCTcomprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions; andone or more output flow channels configured to flow one or more output streams comprising the adipic acid from the reactor.

[0352] Aspect 173 provides an apparatus for making adipic acid comprising:one or more input flow channels configured to flow one or more input streams comprising adiponitrile to a reaction zone of a reactor, wherein the one or more input streams comprise a purge gas that is an inert gas;the reactor comprising the reaction zone, wherein the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of adiponitrile to adipic acid, wherein the reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions; andone or more output flow channels configured to flow one or more output streams comprising the adipic acid from the reactor, wherein the one or more output streams comprise the purge gas and ammonia.

[0353] Aspect 174 provides an apparatus for making a dicarboxylic acid comprising:one or more reactor input flow channels configured to flow one or more reactor input streams comprising one or more C4-C10 aliphatic dinitriles to a reaction zone of a reactor; the reactor comprising the reaction zone, wherein the reactor is configured to maintain the reaction zone at reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions, wherein the reactor comprises a reactor inlet purge stream conduit configured to allow a purge gas to enter the reaction zone, and wherein the reactor comprises a reactor output purge stream conduit configured to allow an ammonia-rich purge stream to exit the reaction zone;INV-23014-WO-PCTone or more reactor output flow channels configured to flow one or more reactor output streams comprising the one or more C4-C10 dicarboxylic acids from the reactor;a separator unit configured to accept the one or more reactor output streams comprising the one or more C4-C10 dicarboxylic acids from the reactor, and configured to output an organic stream and an aqueous stream comprising the one or more C4-C10 dicarboxylic acids, wherein the separator unit is a liquid-liquid separator unit;a vacuum distillation unit configured to accept the organic stream and to output a lower-boiling organic constituents stream and a higher-boiling constituents stream comprising unconverted C4-C10 aliphatic dinitrile;a higher-boiling constituents flow channel configured to flow the higher-boiling constituents stream to the one or more reactor input flow channels;an evaporator unit configured to accept the aqueous stream comprising the one or more C4-C10 dicarboxylic acids and to output water and a concentrated slurry stream comprising the one or more C4-C10 dicarboxylic acids;a concentrated slurry stream separation unit configured to accept the concentrated slurry stream and to output a filtrate stream and a solid product stream comprising the one or more C4-C10 dicarboxylic acids;a filtrate flow channel configured to flow the filtrate to the one or more reactor input channels;a washing unit configured to accept the solid product stream and water, and to output used water and washed solid product stream that comprises the one or more C4-C10 dicarboxylic acids; anda drying unit configured to accept the washed solid product stream and to output a dried solid product stream comprising the one or more C4-C10 dicarboxylic acids.

[0354] Aspect 175 provides an apparatus for making a dicarboxylic acid comprising:one or more reactor input flow channels configured to flow one or more reactor input streams comprising one or more C4-C10 aliphatic dinitriles to a first-stage reaction zone of a first-stage reactor;the first-stage reactor comprising the first-stage reaction zone, wherein the first-stage reactor is configured to maintain the first-stage reaction zone at first-stage reaction zone conditions for a time sufficient to convert water and at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the first-stage reaction zone conditions comprise a temperature greater than or equal to ambient temperatureINV-23014-WO-PCTand less than a supercritical temperature of water under the first-stage reaction zone conditions, and the first-stage reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the first-stage reaction zone conditions, wherein the first-stage reactor comprises a reactor inlet purge stream conduit configured to allow a purge gas to enter the first-stage reaction zone, and wherein the first-stage reactor comprises a first-stage reactor output purge stream conduit configured to allow a first-stage ammonia-rich purge stream to exit the first-stage reaction zone;one or more first-stage reactor output flow channels configured to flow one or more first-stage reactor output streams comprising the one or more C4-C10 dicarboxylic acids from the first-stage reactor;a separator unit configured to accept the one or more first-stage reactor output streams comprising the one or more C4-C10 dicarboxylic acids from the first-stage reactor, and configured to output an organic stream and an aqueous stream comprising the one or more C4-C10 dicarboxylic acids, wherein the separator unit is a solid-liquid separator unit, and wherein the organic stream is a separated solidified stream;a washing unit configured to wash the separated solidified stream with water to form a washed separated solidified stream and used water;a second-stage reactor comprising a second-stage reaction zone, wherein the second-stage reactor is configured to maintain the second-stage reaction zone at second-stage reaction zone conditions for a time sufficient to convert water and at least a portion of aliphatic dinitriles in the washed separated solidified stream to the corresponding one or more C4-C10 dicarboxylic acids, wherein the second-stage reactor is configured to accept the washed separated solidified stream and a second-stage reactor water stream and output a second-stage reactor effluent stream comprising the one or more C4-C10 dicarboxylic acids, and wherein the second-stage reactor comprises a second-stage reactor output purge stream conduit configured to allow a second-stage ammonia-rich purge stream to exit the second-stage reaction zone;an evaporator unit configured to accept the aqueous stream comprising the one or more C4-C10 dicarboxylic acids and the second-stage reactor effluent stream, and to output water and a concentrated slurry stream comprising the one or more C4-C10 dicarboxylic acidsINV-23014-WO-PCTa concentrated slurry stream separation unit configured to accept the concentrated slurry stream and to output a filtrate stream and a solid product stream comprising the one or more C4-C10 dicarboxylic acids;a filtrate flow channel configured to flow the filtrate to the one or more reactor input channels;a washing unit configured to accept the solid product stream and water, and to output used water and washed solid product stream that comprises the one or more C4-C10 dicarboxylic acids; anda drying unit configured to accept the washed solid product stream and to output a dried solid product stream comprising the one or more C4-C10 dicarboxylic acids.

[0355] Aspect 176 provides the method or apparatus of any one or any combination of Aspects 1-175 optionally configured such that all elements or options recited are available to use or select from.

Claims

INV-23014-WO-PCTCLAIMSWhat is claimed is:

1. A method of making a dicarboxylic acid comprising:flowing one or more input streams comprising one or more C4-C10 aliphatic dinitriles and water to a reaction zone of a reactor;maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the reaction zone conditions, and the reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the reaction zone conditions; andflowing one or more output streams comprising the one or more C4-C10 dicarboxylic acids from the reactor.

2. The method of claim 1, wherein the reaction zone is free of ultrasonic irradiation.

3. The method of claim 1, wherein the one or more input streams comprise a purge gas, wherein the purge gas removes ammonia from the reaction zone.

4. The method of claim 3, wherein the purge gas comprises nitrogen, argon, helium, CO2, or a combination thereof.

5. The method of claim 1, wherein the one or more input streams comprise a catalyst, wherein the catalyst comprises an acid catalyst, a basic catalyst, phosphoric acid, tungstated zirconia (W / Zr), zeolite Y, zeolite Beta, Zeolite MFI, ammonium phosphate, ammonium bicarbonate ((NH3)HCO3), ammonium carbonate ((NFh^CCh), or a combination thereof6. The method of claim 5, wherein the catalyst is present in the one or more input streams in an amount that is > 0.001 wt% to < 30 wt% based on the amount of aliphatic dinitrile in the one or more input streams.INV-23014-WO-PCT7. The method of claim 1, wherein the one or more input streams are the only input streams to the reaction zone, wherein catalysts are 0 wt% to 0.001 wt% of the one or more input streams, and wherein diamines are 0 wt% to 0.1 wt% of the one or more input streams.

8. The method of claim 1, wherein the one or more output streams comprise a gaseous output stream comprising a purge gas and ammonia.

9. The method of claim 1, wherein the one or more output streams are the only output streams from the reaction zone, wherein the one or more output streams are substantially free of diamines and polyamides.

10. The method of claim 1, wherein the one or more input streams comprise a concentration of the aliphatic dinitrile in water of 0.1 wt% to 50 wt%.

11. The method of claim 1, comprising a conversion of the aliphatic dinitrile of 90% to 100%, a selectivity of the aliphatic dinitrile to the carboxylic acid of 80% to 100%, and a yield of the carboxylic acid from the aliphatic dinitrile of 50% to 100%.

12. The method of claim 1, comprising subjecting contents of the reaction zone to reaction zone conditions for a reaction duration of 0.01 h to 10 h, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm.

13. The method of claim 1, wherein the aliphatic dinitrile is adiponitrile and the dicarboxylic acid is adipic acid.

14. The method of claim 1, wherein the reactor comprises an autoclave, a column, a tubular reactor, a tank reactor, a plug flow reactor, a packed bed reactor, a slurry reactor, continuously-stirred-tank-reactor (CSTR), flow reactor, pipeline reactor, multi-phase fluidized reactor, or a bubble column reactor.

15. The method of claim 1, further comprising recovering the one or more C4-C10 dicarboxylic acids from the reaction zone and / or from the one or more output streams.INV-23014-WO-PCT16. The method of claim 1, wherein the method has a Global Warming Potential (GWP) Equivalency, determined in terms of kg CO2 equivalents per kg of the formed dicarboxylic acid, that is 0.1% to 99% of that of a process of making the same dicarboxylic acid product by a hydrocarbon feedstock oxidation.

17. The method of claim 1, wherein the reactor is a first-stage reactor and the reaction zone is a first-stage reaction zone, wherein the one or more output streams comprise unreacted dinitriles in addition to the one or more C4-C10 dicarboxylic acids, further comprising separating the unreacted dinitriles and the one or more C4-C10 dicarboxylic acids to form an organic stream comprising the unreacted dinitriles and an aqueous stream comprising the one or more C4-C10 dicarboxylic acids, flowing the organic stream to a second-stage reaction zone of a second-stage reactor, the second-stage reaction zone comprising water, maintaining conditions of the second-stage reaction zone for a time sufficient to convert at least a portion of the aliphatic dinitriles to corresponding one or more C4-C10 dicarboxylic acids, wherein the second-stage reaction zone conditions comprise a temperature greater than or equal to ambient temperature and less than a supercritical temperature of water under the second-stage reaction zone conditions, and the second-stage reaction zone conditions comprise a pressure greater than or equal to atmospheric pressure and less than a supercritical pressure of water under the second-stage reaction zone conditions, and flowing one or more second output streams comprising the one or more C4-C10 dicarboxylic acids from the second-stage reactor.

18. The method of claim 17, further comprising combining the one or more second output streams comprising the one or more C4-C10 dicarboxylic acids from the second-stage reactor and the aqueous stream comprising the one or more C4-C10 dicarboxylic acids to form a product stream, further comprising recovering the one or more C4-C10 dicarboxylic acids from the product stream.INV-23014-WO-PCT19. A method of making adipic acid comprising:flowing one or more input streams comprising adiponitrile and water to a reaction zone of a reactor, wherein the one or more input streams are the only input streams to the reaction zone and wherein the one or more input streams are substantially free of catalysts;maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the adiponitrile to adipic acid, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm; andflowing one or more output streams comprising the adipic acid from the reactor.

20. A method of making adipic acid comprising:flowing one or more input streams comprising adiponitrile and water to a reaction zone of a reactor, wherein the one or more input streams comprise a purge gas that is an inert gas;maintaining conditions of the reaction zone for a time sufficient to convert at least a portion of the adiponitrile to adipic acid, wherein the reaction zone conditions comprise a temperature of 220 °C to 300 °C and a pressure of 30 atm to 200 atm; andflowing one or more output streams comprising the adipic acid from the reactor, wherein the one or more output streams comprise the purge gas and ammonia.

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