Method for making a diamine

Abstract

This document describes a method of making a diamine compound from an aldehydic compound. The method can involve reacting either a dialdehyde, diacetal of dialdehyde, or the combination of the two, with hydrogen and ammonia source in the presence of a heterogeneous catalyst, solvent and optionally, a promoter at reaction conditions to obtain its corresponding diamine in desired yields.

Description

METHOD FOR MAKING A DIAMINEFIELD

[0001] This document relates to a method for making a diamine from an aldehydic compound. Specifically, the present document relates to a method of reductively aminating a diacetal substrate over a heterogeneous catalyst to its corresponding diamine in high yields.BACKGROUND

[0002] Nylon is a family of synthetic polyamide polymers having applications in a variety of industries, including textiles, automotive, machine parts, packaging and consumer goods. Nylon is readily processed into fibers, pellets, molded shapes and films which have exceptional strength and compatibility across a range of temperatures and environments. The most common nylons are nylon-6 (poly-caprolactamide) and nylon-6, 6 (polyhexamethylenediamine adipamide). Adipaldehyde, also known as 1,6-hexanaldehyde, is an industrial intermediate useful, for example, in the production of E-caprolactone (CPLN), adipic acid (AA), 1,6-hexanediol (HDO) and other chemicals that find applications in nylon (or polyamides) manufacturing processes. For example, adipic acid (AA) is one of two monomers used for making nylon-6, 6. Chemicals such as 1,6-hexanediol (HDO) can be converted into its corresponding diamine, 1,6-hexanediamine (HMD), which is the other monomer used for making nylon-6, 6.SUMMARY

[0003] This document describes a method of making a diamine; the method comprising the steps of: contacting an acetal compound with a hydrogen source and an ammonia source in the presence of a heterogeneous catalyst, a solvent and optionally, a promoter in a reaction zone. Specified reaction zone conditions can be maintained for a specified period, and the specified period can be selected to substantially convert the acetal compound to at least one diamine compound. The reaction zone effluent can be recovered such as to obtain the diamine compound. In an example, the acetal is formed as a reaction product of an aldehydic compound. The aldehydic compound can be selected from one or more of the following compounds: Ri-CHO, HCO-Ri-CHO where Ri is selected from C4-C12 hydrocarbon groups. In an example, the acetal can be a reaction product of at least one aldehydic compound selected from the group consisting of butyraldehyde, n-valeraldehyde, caproaldehyde, succinaldehyde, glutaraldehyde and adipaldehyde.

[0004] The acetal can be selected from one or more of the compounds having the following molecular structures:

[0005] Here, R2 can be selected from C2-C12 hydrocarbon groups, Ai, A2, A3, A4 can each be independently selected from C1-C5 alkyl groups, and A5, Ae can each be independently selected from C2-C4 alkyl groups. In an example, the acetal can be selected from the group consisting of diethylene glycol acetal of butyraldehyde, diethylene glycol acetal of valeraldehyde, di ethylene glycol acetal of adipaldehyde, 1,3 -propanediol acetal of butyraldehyde, 1,3 -propanediol acetal of valeraldehyde, 1,3 -propanediol acetal of adipaldehyde, glycerol acetal of butyraldehyde, glycerol acetal of valeraldehyde and glycerol acetal of adipaldehyde.

[0006] The reaction zone conditions can include a temperature ranging from about 45 degrees Celsius (°C) to about 150 °C, ranging from about 45 °C to about 125 °C, or ranging from about 50 °C to about 100 °C. For example, reaction temperature can be within the range of > about 55 °C to < about 75 °C. The reaction zone conditions can include a pressure ranging from about 10 pounds per square inch gauge (Psig) to about 4500 Psig, a pressure ranging from about 50 Psig to about 4000 Psig, or a pressure ranging from about 100 Psig to about 4000 Psig. For example, the reaction pressure can range from > about 200 Psig to < about 500 Psig. One atmosphere (atm.) pressure is equal to about 14.7 Psig pressure. The reaction zone conditions can include a specified residence time, the specified residence time selected to convert at least a portion of the the acetal compound to at least one diamine compound. In an example, the reaction zone specified residence time can be quantified as when the reaction zone pressure ceases to drop below a specified, threshold pressure.

[0007] In an example, the ammonia can be at least one of an ammonia gas, an aqueous solution of ammonia, or an amine. In an example, the heterogeneous catalyst can include a sponge metal catalyst. For example, such suitable sponge metal catalyst can comprise at least one of nickel and cobalt, such as a sponge metal including at least one of Raney® Nickel or Raney® Cobalt. In an example, the solvent can include at least one of an oxygenate or water. For example, the oxygenate can include at least one of an alcohol or an ester. For example, the alcohol solvent can include at least one of methanol, ethanol, propanol and butanol. Such an alcohol solvent can be obtained via a process, such as a hydrocarbon-based synthesis process,by-product or co-product alcohol from a chemical synthesis process, biomass-derived process, a fermentation process, or a combination thereof. In an example, water can be a solvent.

[0008] In an example, promoter can be a metal hydroxide, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, or a combination thereof.

[0009] In an example, the method can include recovering the reaction zone effluent such as to obtain the diamine, including a solid separation step to recover the reaction zone effluent from the heterogeneous catalyst. For example, the solid separation step can include pressure filtration, vacuum filtration, centrifugation, membrane separation, distillation, wiped film evaporation, decantation, gravity settling, or a combination thereof.

[0010] Alternatively or additionally, a method for making 1,6-hexanediamine can involve mixing a diacetal of adipaldehyde with a hydrogen source and an ammonia source in the presence of a heterogeneous catalyst, a solvent, and optionally, a promoter in a reaction zone. Here, the method can include controlling the reaction zone conditions for a specified period to convert the diacetal of adipaldehyde to 1,6-hexanediamine. The method can also include recovering the reaction zone effluent to obtain 1,6-hexanediamine.

[0011] Alternatively or additionally, a method for making 1,6-hexanediamine can involve mixing adipaldehyde with a hydrogen source and an ammonia source in the presence of a heterogeneous catalyst, a solvent, and optionally, a promoter in a reaction zone. Here, the method can include controlling the reaction zone conditions for a specified period to convert adipaldehyde to 1,6-hexanediamine. The method can also include recovering the reaction zone effluent to obtain 1,6-hexanediamine.DETAILED DESCRIPTION

[0012] Certain industrial scale processes for making adipic acid and 1,6-hexanediamine can be capital-intensive, such as involving several complex conversion steps and unit operations. For example, one approach to producing adipic acid involves cyclohexane oxidation and may involve the use of nitric acid which tend to produce nitrous oxide. This approach can involve can be challenging, such as potentially involving a concern of carbon emissions. One approach to producing 1,6-hexanediamine involves a catalytic hydrogenation of 1,6-hexanenitrile (or adiponitrile, which can be referred to herein as ADN). Adiponitrile can be manufactured, e.g., by double hydrocyanation of 1,3 -butadiene, acrylonitrile coupling, or adipic acid ammoniation routes. Such processes can involve certain challenges, such as reliance on a hydrogen cyanide source. Additionally, certain adipic acid ammoniation processes can rely on a corrosive catalyst and can involve exotic, expensive, or rare metallurgy.Further, acrylonitrile coupling can involve industrial-scale electro-chemical process that can be relatively energy intensive.

[0013] An approach to producing a diamine is described in Chinese Publication Serial No. 114426502, including mixing and heating aldehyde compounds (i.e., aldehydes, acetals, or a combination), ammonia, an oxidizing agent, a catalyst and a promoter to obtain nitrile after reaction. However, it would be desirable to produce a diamine more directly from a diacetal. Another approach to producing a diamine is described in United States Pat. Serial No. 10,941,092, involving a two-stage hydroformylation of butadiene. For example, a hydroformylation process can involve a synthesis of adipic acid, 1,6-hexadiamine, and 1,6- hexandiol via a double-n-selective hydroformylation of 1,3 -butadiene, e.g., involving an intermediate of adipic aldehyde diacetal. Here, a diamine such as 1,6-hexadiamine (HMD) can be ultimately produced. For example, 1,6-hexanediol (HDO) can be produced from the diacetal of adipaldehyde (in about 68% yield), which can subsequently be converted to HMD (in about 81% yield). Such an approach to preparing a diamine can involve a challenge of a relatively low overall yield of HMD yield, such as less than about 55%.

[0014] Another approach to producing a diamine is described in United States Pat. Serial No. 6,696,609, such as involving a dialdehyde. However, such an approach involves challenges to selectivity and yield to the desired diamine product.

[0015] One approach to producing an acetal is described in United States Patent Application Publication No. 5312996, involving a hydroformylation process for producing a 1,6-hexanedial. Such an approach can involve reacting a butadiene with hydrogen and carbon monoxide in the presence of rhodium to achieve conversion of the butadiene to the 1,6- hexanedial. Here, acetals can be formed via reaction of the aldehyde with a 1 ,2-diol, 1 ,3-diol, 2,4-diol, such as in the presence of an acetalization catalyst (e.g. sulfuric acid, phosphoric acid, etc.).

[0016] A scientific journal publication, J. Org. Chem. 1996, 61, 3849-3862, describes examples of reductive amination of aldehydes and ketones wherein the acetals were unreactive under certain conditions.

[0017] The present inventors have recognized the benefits of producing one or more industrial intermediates, e.g., adipic acid, adiponitrile (ADN), 1,6-hexanediamine (HMD), hexanediol (HDO), etc., from alternate production route(s) of less complexity and / or using relatively inexpensive starting materials as compared to certain other approaches (e.g.: aldehydic compounds, such as aldehydes, dialdehydes, acetals or diacetals of aldehydic compounds). The present inventors have conceived of a process to address an industrial needfor improved production of a diamine and the corresponding precursors, e.g., exhibiting desired conversion and selectivity. This document describes a technical and economic process for diamine production and the corresponding precursors. An example is HMD production either from adipaldehyde or its corresponding precursor comprising two acetal groups in the first and sixth position. Another example is the production of cadaverine or 1,5-pentamethylene diamine (also referred to herein as PMD or PMDA) either from glutaraldehyde or its corresponding precursor comprising two acetal groups in the first and fifth position.

[0018] This document relates to a first single step conversion of the diacetal directly to its corresponding diamine, e.g., without requiring to first hydrolyze the diacetal to diol. The diacetal may be produced by reacting its corresponding dialdehyde with a dialcohol / glycol (e.g., mono- or di-ethylene glycol, propylene glycol, glycerol, etc.. This document also relates to reductive amination of a dialdehyde to its corresponding diamine via the diacetal intermediate. For example, a one-step process as described herein can preserve a dialdehyde substrate, e.g., by reducing or minimizing its oligomerization. Such a one-step process can occur under certain “mild” process conditions, e.g., regarding temperature and pressure, with a substantially complete conversion of the substrate and involving a relatively high desired product yield.

[0019] Adipaldehyde, a key intermediate in the conversion of cyclohexene to nylon intermediates, can be susceptible to self-condensation, such as to afford oligomeric products thereby reducing the yield of the desirable product, e.g.: 1,6-hexanediamine (HMD). It may be possible to circumvent this self-condensation by protecting the dialdehyde as a diacetal. Effective catalysts can promote the subsequent indirect reductive amination of the diacetal into its corresponding diamine product. It can be desired that certain catalysts for the reductive amination of dialdehyde diacetal be tolerant of and substantially unreactive toward alcohols, e.g., when used as a solvent. For example, spongy nickel (e.g.: Raney® nickel) can provide an effective heterogeneous catalyst for the direct reductive amination of acetals formed from dialdehydes to diamines. For example, spongy nickel can involve substantially no poisoning of the catalyst, no oligomerization of the dialdehyde, and no appreciable alkylation of the product by resulting alkanol.

[0020] Techniques described herein can help provide a commercially viable route for making a diamine starting from an acetal (derived from an aldehydic compound (e.g. : HMD from adipaldehyde; cadaverine from glutaraldehyde; putrescine from succinaldehyde)). As against the current high capital intensity processes and dilute bio-synthesis processes for putrescine and cadaverine, etc., the disclosed one-step method from the acetal may offer asmaller-scale, investment-efficient option for these diamine production with high product yields. The method can involve a one-step chemical process, can use, e.g., Raney® type catalysts (spongy metal type), solvents (water, alcohols, esters), promoters (e.g.: caustic), mild temperatures and moderate pressures. The substrate conversion can be complete and the product yields can be relatively high, thus, making it easy to recover the desired product from trace impurities. The resulting diamine product can be especially desirable, e.g., for industrial application. For example, HMD is a monomer in nylon-6, 6 production, while cadaverine or PMDA is a monomer in nylon-5X production.Material Names and Abbreviations used in the disclosure:

[0021] Adipaldehyde 1,6-hexane dialdehyde;

[0022] AA adipic acid or 1,6-hexane diacid;

[0023] ADN adiponitrile or 1,6-hexane dinitrile;

[0024] BD 1,3-butadiene;

[0025] Cadaverine (PMD) 1,5-pentamethylene diamine or 1,5-diaminopentane;

[0026] Glutaraldehyde 1,5-pentamethylene dialdehyde;

[0027] HDO hexanediol or 1,6-hexanediol;

[0028] HMD (HMD A) 1,6-hexanedi amine or hexamethylene diamine;

[0029] Putrescine (DAB) 1.4-diaminobutane or 1,4-butanediamine;

[0030] Succinaldehyde 1.4-butane dialdehyde;

[0031] A dialdehyde of adipic acid, industrially known as hexanedial, adipaldehyde,1,6-hexanedial, adipic aldehyde or adipic dialdehyde (CAS No. 1072-21-5), is commercially available. Adipaldehyde used in the examples was produced by INVISTA and was of 99.9 wt% purity.

[0032] A diacetal of adipaldehyde with 95 wt% purity was prepared by INVISTA using ethylene glycol and used in the examples.

[0033] The examples used commercially available spongy nickel type catalysts (e.g.: Raney® nickel) such as, Raney® Ni 2400 and Raney® Co 2724, and obtained from W. R. Grace, Davison Division. While not mentioned, other Raney® type catalysts may also be suitable.Experimental Method

[0034] All experiments were conducted in semi-batch mode in a 300 mL, high- pressure, stirred autoclave, such as Model 4560 produced by Parr Instrument Company, in an explosion proof barricade. The reactor was equipped with baffles, a hollow shaft gas-entrainment impeller and was stirred at 2000 RPM to ensure thorough gas-liquid mixing during the reaction. A 1 / 8 HP variable speed stirrer motor was adapted with a larger pulley to permit stirring speeds in excess of about 1000 RPM for increased gas entrainment. The reactor facilities for one or both of gas and liquid sampling, e.g., during operation.

[0035] In an example, the as-received catalyst was washed three times with water and weighed out using the pycnometry method. The slurry was then transferred to the reactor, along with the substrate (typically adipaldehyde diacetal), and solvent (water or alcohol) inside a glove-box under argon. The reactor was then sealed, removed from the glove-box, mounted to the heating and agitation system inside a fume hood, pressure tested with argon, and then heated to the desired temperature (typically 75 °C). From cylinders of ammonia and hydrogen the pressure was increased to the desired level (typically 500 Psig). The feed cylinders were connected to Brooks mass-flow-controllers operating as a flow meter which maintained the pressure by introducing make-up feed gas to the reactor. The liquid phase of the reactor was sampled for analysis.

[0036] In a stirred autoclave reactor, pre-weighed amounts of a catalyst, solvent, promoter (e.g., 50 wt.% aqueous sodium hydroxide solution), and substrate (e.g., adipaldehyde diacetal) were charged. The autoclave reactor was closed and vapor space was displaced with argon three times. The reactor was then pressurized with argon to check for leaks. The argon was then vented, and the vapor space was charged with hydrogen and ammonia to bring the pressure to 200 Psig. The reactor was then heated to the desired temperature, and then the pressure was raised to 500 Psig with hydrogen and ammonia, and the stirring set to 2000 RPM. The reaction was allowed to continue at these conditions. Progress of the reaction was monitored, such as via sensing a decrease in pressure over time indicating the real-time consumption of hydrogen and ammonia. The reaction was considered complete when there was no further decline in pressure. At this point the pressure was vented while maintaining a temperature high enough to avoid freezing of the target diamine product.

[0037] The reaction zone conditions can be maintained for a specified period, the specified period selected to promote conversion of the substrate to at least one diamine product. The specified period can be within a range of about 10 minutes and about 10 hours (hrs), such as less than about 8 hrs, less than about 6 hrs, less than about 5 hrs, or less than about 4 hrs. In an example, the specified period may be within a range of about 20 minutes and about 5 hrs, or within a range of about 30 minutes and about 4 hrs, or within a range of about 1 hr and about 5 hrs.

[0038] The final mixture wasdrained from the reactor, and product analysis was conducted by gas chromatography.

[0039] Analysis of the liquid phase products of each reaction was carried-out on a Hewlett-Packard 7890 GC equipped with a methyl-silicone gum capillary column (DB-5), a flame-ionization detector, and quantitated using a calibration curve. The rate of HMD formation was calculated using the GC analysis of the liquid phase, and / or the rate of feed consumption through the flow meter.

[0040] Data analysis: Consumption of hydrogen within the reactor was continuously monitored and downloaded to Excel for analysis. GC analysis was used to determine selectivity.

[0041] GC analysis: The samples were diluted with ethanol, charged with an internal standard (di ethyl acetamide) and analyzed by gas chromatography. In an example, GC samples can be more inert or stable in ethanol than in methanol solution. For example, in methanol side-reactions can occur over the course of days, which can change the identity and concentrations of certain components in the samples. In ethanol, samples can remain stable for at least two-weeks. The samples can be analyzed on a Hewlett-Packard 7890 GC equipped with a methyl-silicone gum capillary column (DB-5) with a 1 pm film, which can be preconditioned with repeated injections of a solution of concentrated HMD before use. The column carrier gas can be about 2 cubic centimeters per minute (cc / min) of Helium (He) (constant pressure mode) and the split ratio can be about 25: 1 after a 1 microliter (pL) injection. The heating profile can be about 60 °C for 1 minute, such as 7 °C per minute until 275 °C, such as held for 10 minutes. The GC detector can include a flame ionization detector. In an example, the GC analysis technique can involve an internal standard (0.05 g DEAC in 5 mL ethanol).NOTES AND EXAMPLES

[0042] Various aspects of the present disclosure can be better understood by reference to the following Examples which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.Example 1

[0043] To the 300 mL stirred autoclave reactor, 4.5 g Raney® Ni 2400, 4.6 g water, 0.5 g caustic soda (50 wt.% aqueous sodium hydroxide solution), and 60 g of adipaldehyde diacetal were charged. The reactor was closed and vapor space was displaced with argon three times.The reactor was then pressurized with argon to check for leaks. The argon was then vented, and the vapor space was charged with hydrogen and ammonia to bring the pressure to 200 Psig. The reactor was then heated to 75 °C, and then the pressure was raised to 500 Psig with hydrogen and ammonia, and the stirring set to 2000 RPM. Progress of the reaction was monitored by the decrease in pressure. The reaction was considered complete when there was no further decline in pressure. At this point the pressure was vented while maintaining a temperature of 60-80 °C to avoid freezing of the diamine product, 1,6-hexanediamine (HMD). The final mixture was drained from the reactor, and product analysis was conducted by gas chromatography.Example 2

[0044] Example 1 was repeated, except that Raney® Co 2724 was used.Example 3

[0045] Example 1 was repeated, except that adipaldehyde was used as the substrate instead of adipaldehyde diacetal.Example 4

[0046] Example 2 was repeated, except that adipaldehyde was used as the substrate instead of adipaldehyde diacetal.Example 5

[0047] Example 1 was repeated, except that the reaction temperature was reduced to 55 °C.Example 6

[0048] Example 1 was repeated, except that no caustic soda was added to the reaction.Example 7

[0049] Example 1 was repeated, except that caustic soda added to the reaction was 0.2 g-Example 8

[0050] Example 7 was repeated, except that ethanol was added to the reaction in place of water.Example 9

[0051] Example 5 was repeated, except that ethanol was added to the reaction in place of water.Example 10

[0052] Example 1 was repeated, except that ethanol was added to the reaction in place of water.

[0053] TABLE 1 below is a summary of results for Examples 1 through 10.TABLE 1f Yield is based on substrate charged (e.g. adipaldehyde diacetal);{ The term “Ad-CHO diacetal” means adipaldehyde diacetal;Conversion was determined to be complete in all experiments by GC analysis;A Trace impurities in the product include hexamethyleneimine, diaminocyclohexane, and aminomethylcylopentylamine;*Caustic used was a 50 wt.% sodium hydroxide solution in water.Distilled water was used in the examples Ethanol used was of 99 wt% purity.

[0054] The data presented in Table 1 show the effectiveness of slurried nickel and cobalt catalysts on the yield of HMD produced from the reductive amination of adipaldehyde and adipaldehyde diacetal. In each example, the substrate conversion was complete as determined by GC analysis.

[0055] It was observed that reductive amination of the diacetal obtained comparatively better diamine yields than direct reductive amination of adipaldehyde (Examples 3 and 4). Surprisingly and unexpectedly, the diamine yields in the 88-92% range were observed for the adipaldehyde substrate, and indicative of the reduced or minimized oligomerization and selfcondensation during the reaction.

[0056] With all other reaction parameters being the same, Examples 1, 6 and 7 demonstrated the effect of the presence (or absence) and the total amount of sodium hydroxide added to the reaction on the overall yield of HMD obtained. Example 6 obtained 92.7 % HMD yield in the absence of caustic, while the HMD yields improved to 95.1% (Example 7; 0.2g caustic) and 97.1% (Example 1; 0.5g caustic). In all experiments, the caustic used was a 50 wt.% sodium hydroxide solution in water.

[0057] With all other reaction parameters being the same, the reaction temperature effect was apparent from Examples 1, 5 (water as solvent) and Examples 9, 10 (ethanol as solvent). Reducing the reaction temperature from 75 °C to 55 °C showed a slight HMD yield improvement, namely, 97.1 % [Ex. 1] to 98.3 % [Ex. 5] for water used as a solvent, and 96.5 % [Ex. 10] to 98.3 % [Ex. 9] for ethanol used as a solvent.

[0058] Comparisons between Ex. 7 with Ex. 8; between Ex. 5 and Ex. 9; and betweenEx. 1 and Ex. 10 showed that switching ethanol versus water for the solvent did not have much impact on reaction performance.Example 11

[0059] Example 1 is repeated, except that a diethylene glycol diacetal of succinaldehyde is used as the substrate. The 1,4-butanediamine (DAB or putrescine) is obtained in high yield.Example 12

[0060] Example 9 is repeated, except that a 1,3-propylene glycol diacetal of glutaraldehyde is used as the substrate. The 1,5-diaminopentane (PMD or cadaverine) is obtained in high yield.Example 13

[0061] Example 5 is repeated, except that a di ethylene glycol diacetal of 1,9-nonanedial is used as the substrate. The 1,9-diaminononane is obtained with high selectivity and overall yield.Example 14

[0062] Example 10 is repeated, except that a diethylene glycol diacetal of 1,12- dodecanedial is used as the substrate. The 1,12-dodecanediamine is obtained with high yield.Example 15

[0063] Example 1 is repeated, except that a glycerol diacetal of 1,4-benzenedial (terephthalaldehyde) is used as the substrate. The para-phenylenediamine (1,4- benzenediamine or PPD) is obtained with high yield.

[0064] Similarly, the isomers of para-phenylenediamine, namely, orthophenylenediamine (OPD) and meta-phenylenediamine (MPD), may be produced, according to the Example 1 method, in high yields starting from their corresponding diacetals of dialdehydes, namely, 1,2-benzenedial and 1,3 -benzenedi al. The disclosed process, therefore, provides an alternate route of making such industrially important intermediates with improved selectivity and overall yields. The conventional processes are more complex and require nitrobenzenes, produced from benzene dinitration, that are cumbersome to deal with.

[0065] 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.

[0066] 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.

[0067] In the methods described herein, the acts can 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. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0068] 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.

[0069] 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 the composition is about 0 wt% to about 5 wt% of 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. The term “substantially free of’ can mean having a trivial amount of, such that a composition is about 0 wt% to about 5 wt% of 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%.

[0070] All publications, including non-patent literature (e.g., scientific journal articles), patent application publications, and patents mentioned in this specification are incorporated by reference as if each were specifically and individually indicated to be incorporated by reference.

[0071] It is understood that the descriptions herein are intended to be illustrative, andnot restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Moreover, the terms “first,” “second,” “third,” and the like are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0072] The term “dial” as used herein, is an abbreviation for dialdehyde and commonly used in the industry.

[0073] The term “aldehydic compound” as used herein, refers to a class of organic compounds and include an aldehyde [R-CHO], a dialdehyde [HCO-R-CHO], an acetal of aldehyde or a diacetal of dialdehyde. The acetal or diacetal can be produced by reacting a dialcohol or glycol with the suitable aldehyde or dialdehyde. As an example, a diethylene glycol acetal of butyraldehyde can be produced by reacting diethylene glycol [DEG] with butyraldehyde. In another example, a glycerol diacetal of adipaldehyde may be produced by reacting glycerol with adipaldehyde. These chemical reactions are known in the industry.

[0074] Non-limiting examples of the suitable dialdehydes may include succinaldehyde, glutaraldehyde, adipaldehyde, heptanediald, octanedial, nonanedial, decanedial, undecanedial, dodecanedial, and such. Other examples may include cyclic dialdehydes, such as, cyclopentyl dialdehyde, 1,3 -cyclohexyl dicarbaldehyde, 1,4-cyclohexyl dicarbaldehyde, cycloheptyl dialdehyde, etc. Some examples of aromatic dialdehydes may include terephthalic aldehyde and isophthalic aldehyde.

[0075] The low-carbon containing dialdehydes, such as succinaldehyde and glutaraldehyde, may be produced from biomass-derived feedstocks and fermentation processes.

[0076] The higher carbon containing dials may be produced by, for example hydroformylation of unsaturated aldehydes with one less carbon atom than that of the desired dialdehydes or diolefins having two less carbon atoms than that of the desired dialdehydes. Other industrial processes for making Ce and higher dials may include ozone or H2O2 reduction of their corresponding cyclic olefins having the same carbon atoms as that of the desired dialdehydes, or by reduction of dicarboxylic acids having the same number of carbon atoms as that of the desired dialdehydes.

[0077] In one instance, adipaldehyde may be produced by ozone reduction of cyclohexene. In another instance, 1,5,9-cyclododecatriene (CDDT), commercially producedfrom cyclotrimerization of 1,3 -butadiene, may be contacted with ozone to produce dodecyl (or 12-carbon) aldehydes as disclosed in United States Patent No. 4085127. Similarly, 1,5- cyclooctadiene (COD), which is a co-product of the butadiene cyclotrimerization, may undergo ozone reduction to afford octyl (or 8-carbon) aldehydes.

[0078] While the disclosed subject matter in the detailed description is 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.

Claims

CLAIMSWhat is claimed is:

1. A method of making a diamine; the method comprising: contacting an acetal compound, having a hydrogen source and an ammonia source, in a presence of a heterogeneous catalyst and a solvent in a reaction zone; controlling reaction zone conditions for a specified period to convert the acetal compound to at least one diamine compound; and recovering a reaction zone effluent to obtain the diamine compound.

2. The method of claim 1, wherein the acetal is a reaction product of an aldehydic compound.

3. The method of claim 2 wherein the aldehydic compound is selected from one or more of the following compounds: Ri-CHO, HCO-Ri-CHO; wherein Ri is selected from C4- C12 hydrocarbon groups.

4. The method of any one of claims 1-3, wherein the acetal is a reaction product of at least one aldehydic compound selected from the group consisting of butyraldehyde, n- valeraldehyde, caproaldehyde, succinaldehyde, glutaraldehyde and adipaldehyde.

5. The method of claim 4, wherein the acetal is selected from the group consisting of di ethylene glycol acetal of butyraldehyde, di ethylene glycol acetal of valeraldehyde, diethylene glycol acetal of adipaldehyde, 1,3 -propanediol acetal of butyraldehyde, 1,3- propanediol acetal of valeraldehyde, 1,3 -propanediol acetal of adipaldehyde, glycerol acetal of butyraldehyde, glycerol acetal of valeraldehyde and glycerol acetal of adipaldehyde.

6. The method of claim 1, wherein the acetal is selected from one or more of the compounds having the following molecular structures:wherein, R2 is selected from C2-C12 hydrocarbon groups, Ai, A2, A3, A4 are each independently selected from C1-C5 alkyl groups, and A5, Ae are each independently selected from C2-C4 alkyl groups.

7. The method of claim 1, wherein controlling the reaction zone conditions includes controlling a temperature within a temperature range, selected from the group consisting of 45-150 °C, 45-125 °C and 50-100 °C.

8. The method of claim 1, wherein controlling the reaction zone conditions includes controlling a pressure range, selected from the group consisting of 10-4500 Psig, 50-4000 Psig and 100-4000 Psig.

9. The method of claim 1, wherein controlling the reaction zone conditions includes determining a specified residence time, determined to convert at least a portion of the acetal compound to at least one diamine compound when a reaction zone pressure ceases to drop from a specified set pressure value.

10. The method of claim 1, wherein the ammonia source is selected from ammonia gas, an aqueous solution of ammonia and an amine.

11. The method of claim 1, wherein the heterogeneous catalyst is a sponge metal.

12. The method of claim 11 where the sponge metal comprises at least one of nickel and cobalt.

13. The method of claim 11 wherein the sponge metal is selected from Raney® Nickel and Raney® Cobalt.

14. The method of claim 1, wherein the solvent comprises an oxygenate.

15. The method of claim 14 wherein the oxygenate is selected from water, alcohol and ester.

16. The method of claim 15, wherein the alcohol is selected from methanol, ethanol, propanol and butanol.

17. The method of claim 15, wherein the alcohol is obtained from a process selected from the group consisting of hydrocarbon-based synthesis process, by-product or co-product alcohol from a chemical synthesis process, biomass-derived process and fermentation process.

18. The method of claim 1 where the contacting is carried out further in the presence of a promoter in the reaction zone.

19. The method of claim 18, wherein the promoter is a metal hydroxide.

20. The method of claim 19 wherein the metal hydroxide is selected from sodium hydroxide, potassium hydroxide, calcium hydroxide and barium hydroxide.

21. The method of claim 1, wherein recovering the reaction zone effluent to obtain the diamine compound further comprises a solid separation step to recover the reaction zone effluent from the heterogeneous catalyst.

22. The method of claim 21, wherein the solid separation step is selected from the group consisting of pressure filtration, vacuum filtration, centrifuge, membrane separation, distillation, wiped film evaporation, decantation and gravity settling.

23. A method of making 1,6-hexanediamine; the method comprising: mixing a diacetal of adipaldehyde with a hydrogen source and an ammonia source in a presence of a heterogeneous catalyst and a solvent in a reaction zone; controlling reaction zone conditions for a sufficient time to effectively convert the diacetal of adipaldehyde to 1,6-hexanediamine; and recovering a reaction zone effluent to obtain 1,6-hexanediamine.

24. A method of making 1,6-hexanediamine; the method comprising: mixing adipaldehyde with a hydrogen source and an ammonia source in a presence of a heterogeneous catalyst and a solventin a reaction zone;controlling reaction zone conditions for a sufficient time to effectively convert adipaldehyde to 1,6-hexanediamine; and recovering a reaction zone effluent to obtain 1,6-hexanediamine.

25. The method of claim 23 or 24 wherein the reaction zone further contains a promoter.