HK1180303A - Processes for producing diaminobutane (dab), succinic dinitrile (sdn) and succinamide (dam) - Google Patents

Abstract

Processes that make nitrogen-containing compounds include converting succinic acid (SA) or monoammonium succinate (MAS) derived from a diammonium succinate (DAS)- or MAS-containing fermentation broth to produce such compounds including diaminobutane (DAB), succinic dinitrile (SDN), succinic amino nitrile (SAN),succinamide (DAM), and related polymers.

Description

Process for the preparation of Diaminobutane (DAB), Succinonitrile (SDN) and succinamide (DAM)

RELATED APPLICATIONS

This application claims priority from united states provisional application No. 61/346,145, filed 5/19/2010, the subject matter of which is incorporated herein by reference.

Technical Field

The present application relates to processes for the preparation of nitrogen-containing compounds such as Diaminobutane (DAB), Succinonitrile (SDN) and succinamide (DAM) from Succinic Acid (SA) and monoammonium succinate (MAS) prepared by fermentation.

Background

Certain carbonaceous products of sugar fermentation are considered as alternatives to petroleum-derived materials for use as feedstocks for the manufacture of carbon-containing chemicals. One such product is MAS.

MAS-related substances, i.e. SA, can be prepared by microorganisms using fermentable carbon sources (e.g. sugars) as starting materials. However, the most commercially viable succinic acid producing microorganisms described in the literature neutralize the fermentation broth to maintain a pH suitable for maximum growth, conversion and productivity. Typically, succinic acid is converted to diammonium succinate (DAS) by adding ammonium hydroxide to the fermentation broth to maintain the pH of the fermentation broth at or near 7. DAS can be converted to MAS to obtain MAS from the fermentation broth.

Kushiki (Japanese published patent application with publication No. 2005-139156) discloses a method of obtaining MAS from an aqueous solution of DAS which can be obtained from a fermentation broth to which an ammonium salt is added as a counter ion. Specifically, MAS is crystallized from an aqueous solution of DAS by the following steps: acetic acid is added to the aqueous solution of DAS to adjust the pH of the solution to between 4.6 and 6.3, thereby crystallizing impure MAS from the solution.

Masuda (Japanese unexamined patent publication No. P2007-254354, 10.4.2007) describes a molecular formula of H₄NOOCCH₂CH₂COONH₄The portion of the dilute aqueous solution of ammonium succinate is deaminated. As can be seen from the disclosed formula, "ammonium succinate" is diammonium succinate. Masuda removes water and ammonia by heating a solution of ammonium succinate to produce a solid succinic acid-based composition containing at least one of monoammonium succinate, succinic acid, succinamide, succinimide, succinamide or succinate ester in addition to the ammonium succinate. Therefore, it is presumed that, similarly to Kushiki, Masuda also discloses a method leading to impure MAS. Both the Kushiki and Masuda processes produce materials that need to be subjected to various purification means to produce high purity MAS.

Biologically derived MAS as well as SA (e.g., SA obtained from MAS itself) are platform molecules for the synthesis of many commercially important chemicals and polymers. It is therefore highly desirable to provide a purification technique that flexibly integrates the clear, commercially viable routes to derivatives such as DAB, SDN and DAM. Due to the lack of an economically and technically feasible solution for converting fermentation-derived SA/MAS to DAB, SDN, Succinic Amino Nitrile (SAN) and DAM, it would be beneficial to provide a process for providing a cost-effective SA/MAS stream with a purity sufficient for direct hydrogenation.

Disclosure of Invention

The present invention provides a process for the preparation of a nitrogen-containing compound of SA, the process comprising: (a) providing a clarified DAS-containing fermentation broth; (b) distilling the broth to form an overhead that comprises water and ammonia and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% (weight percent) water; (c) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS; (d) separating at least a portion of the solid portion from the liquid portion; and (e) (1) contacting the solid portion with hydrogen and optionally with an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or (2) dehydrating at least a portion of the solid portion to produce SDN; or (3) dehydrating at least a portion of the solid portion to produce a DAM; and (f) recovering the DAB, the SDN or the DAM.

The present invention also provides a process for preparing a nitrogen-containing compound of SA, the process comprising: (a) providing a clarified DAS-containing fermentation broth; (b) distilling the broth to form a first overhead that comprises water and ammonia, and a first liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water; (c) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS; (d) separating the solid portion from the liquid portion; (e) recovering the solid portion; (f) dissolving the solid portion in water to produce an aqueous MAS solution; (g) distilling the aqueous MAS solution at a temperature and pressure sufficient to form a second overhead that includes water and ammonia, and a second bottoms that includes a major portion of SA, a minor portion of MAS, and water; (h) cooling and/or evaporating the second bottoms to cause the second bottoms to separate into a second liquid portion in contact with a second solid portion, preferably consisting essentially of SA and substantially free of MAS; (i) separating at least a portion of the second solid portion from the second liquid portion; and (j) (1) contacting the second solid portion with hydrogen and an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or (2) dehydrating at least a portion of the second solid portion to produce SDN; or (3) dehydrating at least a portion of the second solid portion to produce DAM; and (k) recovering the DAB, the SDN, or the DAM.

The present invention also provides a process for the preparation of a nitrogen-containing compound, the process comprising: (a) providing a clarified MAS-containing fermentation broth; (b) optionally MAS, DAS, SA, NH₃And/or NH₄ ⁺Adding to the fermentation broth to preferably maintain the pH of the fermentation broth below 6; (c) distilling the broth to form an overhead that comprises water and optionally ammonia, and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water; (d) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS; (e) separating at least a portion of the solid portion from the liquid portion; and (f) (1) contacting the solid portion with hydrogen and optionally with an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or (2) dehydrating at least a portion of the second solid portion to produce SDN; or (3) dehydrating at least a portion of the second solid portion to produce DAM; and (g) recovering the DAB, the SDN, or the DAM.

The present invention also provides a process for the preparation of a nitrogen-containing compound, the process comprising: (a) providing a clarified MAS-containing fermentation broth; (b) optionallyMAS, DAS, SA, NH₃And/or NH₄ ⁺Adding to the fermentation broth to preferably maintain the pH of the fermentation broth below 6; (c) distilling the broth to form an overhead that comprises water and optionally ammonia, and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water; (d) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS; (e) separating the solid portion from the liquid portion; and (f) recovering the solid portion; (g) dissolving the solid portion in water to produce an aqueous MAS solution; (h) distilling the aqueous MAS solution at a temperature and pressure sufficient to form a second overhead that includes water and ammonia, and a second bottoms that includes a major portion of SA, a minor portion of MAS, and water; (i) cooling and/or evaporating the second bottoms to cause the second bottoms to separate into a second liquid portion in contact with a second solid portion, preferably consisting essentially of SA and substantially free of MAS; (j) separating at least a portion of the second solid portion from the second liquid portion; and (k) (1) contacting the solid portion with hydrogen and an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or (2) dehydrating at least a portion of the solid portion to produce SDN; or (3) dehydrating at least a portion of the solid portion to produce a DAM; and (l) recovering the DAB, the SDN, or the DAM.

Drawings

Figure 1 schematically shows the complete process for the preparation of SA/MAS obtained by fermentation and further conversion of SA/MAS to DAB and SDN and shows the two-stage deamination of DAS with MAS crystallization between the two stages;

figure 2 schematically illustrates various routes for converting MAS to DAB, SDN and DAM and other intermediates and derivatives;

figure 3 schematically illustrates various pathways for converting SA to DAB, SDN and DAM and other intermediates and derivatives; and

figure 4 is a graph showing the solubility of MAS in water and a 30% aqueous DAS solution as a function of temperature.

Detailed Description

It should be understood that at least a portion of the following description, unlike the appended claims, is intended to refer to representative examples of methods selected for illustration in the accompanying drawings and is not intended to define or limit the invention.

The method of the present invention may be understood by reference to fig. 1, which fig. 1 shows a representative example of the method of the present invention in flow chart form.

The growth vessel is typically an in situ steam-sterilized fermentor that may be used to culture a microbial culture medium (not shown) that is subsequently used to prepare a fermentation broth containing DAS, MAS and/or SA. Such growth vessels are known in the art and are not discussed further.

The microbial culture medium can include a microorganism capable of producing SA from a fermentable carbon source (e.g., carbohydrate sugars). Representative examples of microorganisms include: escherichia coli (Escherichia coli or E.coli), Aspergillus niger (Aspergillus niger), Corynebacterium glutamicum (Corynebacterium glutamicum) (also known as Brevibacterium flavum), Enterococcus faecalis (Enterococcus faecalis), Veillonella parvum, Actinobacillus succinogenes (Actinobacillus succinogenes), Mannheimia succinogenes (Mannheimia succiniciproducens), Anaerobiospirillum succinogenes (Anaerobiospirillum succiniciproducens), Penicillium Paecilomyces (Paecilomyces variotii), Saccharomyces cerevisiae (Saccharomyces cerevisiae), Bacteridium fragilis (Bacillus fragilis), Salmonella typhimurium (Lactobacillus), Candida parapsilosis (Candida parapsilosis), Candida parapsilosis (Candida mycoides), Candida mycoides (Candida mycoides), Candida mycoides (Candida mycoides, Candida myco, Candida sanariensis (Candida sonorensis), Candida utilis (Candida utilis), Candida born (Candida zeylanoides), Debaryomyces hansenii (Debaryomyces hansenii), Fusarium oxysporum (Fusarium oxysporum), Humicola lanuginosa (Humicola lanuginosa), Klebsiella citrina (Kloeckera apiculata), Kluyveromyces lactis (Kluyveromyces lactis), Kluyveromyces wilfordii (Kluyveromyces wilfordii), Penicillium penicillium (Penicillium purpureum), Pichia anomala (Pichia anomala), Pichia pastoris (Pichia pastoris), Pichia pastoris (Pichia pastoris), Pichia media (Pichia pastoris), Pichia pastoris) strain (Pichia pastoris), Pichia pastoris (Pichia pastoris) or (Pichia pastoris), Pichia pastoris (Pichia pastoris) or (, Mixtures thereof and the like.

A preferred microorganism is the E.coli strain deposited with the ATCC under accession number PTA-5132. More preferred is this E.coli strain with the three antibiotic resistance genes (cat, amphl, tetA) removed. The removal of the antibiotic resistance genes cat (coding for resistance to chloramphenicol) and ampll (coding for resistance to kanamycin) can be carried out by the so-called "lambda-red" method described in the following literature, the subject matter of which is incorporated herein by reference: datsenko KA and Wanner BL., national institute of sciences (American society for science), 6.6.2000; 97(12)6640-5. The tetracycline resistance gene tetA can be removed using the method initially described by Bochner et al in the following references, the subject matter of which is incorporated herein by reference: jbacteriol, 8 months 1980; 143(2): 926-933. Glucose is the preferred fermentable carbon source for the microorganism.

Fermentable carbon sources (e.g., carbohydrates and sugars), optionally nitrogen sources and complex nutrients (e.g., corn steep liquor), additional media components (such as vitamins, salts, and other substances that may enhance cell growth and/or product formation), and water may be added to the growth vessel for the growth and maintenance of the microbial culture medium. Generally, the microbial culture medium is grown under aerobic conditions, which are provided by blowing oxygen-rich gas (e.g., air, etc.). Typically, an acid (e.g., sulfuric acid, etc.) and ammonium hydroxide are provided for pH control during growth of the microbial culture medium.

In one example (not shown), the oxygen-rich gas is changed to an oxygen-deficient gas (e.g., CO)₂Etc.) while the aerobic conditions in the growth vessel (provided by blowing oxygen-rich gas) are switched to anaerobic conditions. The anaerobic environment causes the in situ bioconversion of the fermentable carbon source to succinic acid in the growth vessel. Ammonium hydroxide is provided for pH control during bioconversion of the fermentable carbon source to SA. Due to the presence of ammonium hydroxide, the SA produced is at least partially neutralized to DAS, such that a fermentation broth comprising DAS is produced. CO 2₂Additional carbon sources for the preparation of SA are provided.

In another example, the contents of the growth vessel may be transferred to a separate bioconversion vessel by means of a flow to bioconvert the carbohydrate source to SA. Will be anoxic (e.g., CO)₂Etc.) are blown into the bioconversion vessel to provide anaerobic conditions that initiate the production of SA. Ammonium hydroxide is provided for pH control during bioconversion of the carbohydrate source to SA. The SA produced is at least partially coated due to the presence of ammonium hydroxideThe neutralization is DAS, such that a fermentation broth comprising DAS is prepared. CO 2₂Additional carbon sources for the preparation of SA are provided.

In another example, the bioconversion can be performed at a relatively low pH (e.g., 3 to 6). A base (ammonium hydroxide or ammonia) may be provided for pH control during bioconversion of the carbohydrate source to SA. Depending on the desired pH, SA is prepared, or at least partially neutralized, to MAS, DAS or mixtures comprising SA, MAS and/or DAS, due to the presence or absence of ammonium hydroxide. Thus, optionally, in an additional step, SA produced during bioconversion may be subsequently neutralized by providing ammonia or ammonium hydroxide, resulting in a fermentation broth comprising DAS. Thus, "DAS-containing fermentation broth" generally refers to a fermentation broth that includes DAS and possibly any number of other components (such as MAS and/or SA) added and/or produced by bioconversion or other processes. Similarly, "MAS-containing fermentation broth" generally refers to a fermentation broth comprising MAS and possibly any number of other components (such as DAS and/or SA) added and/or produced by bioconversion or other processes.

The fermentation broth resulting from the bioconversion of a fermentable carbon source (in a growth vessel or bioconversion vessel, depending on where the bioconversion occurs) typically contains insoluble solids, such as cellular biomass and other suspended matter, which are transferred to a clarification device with a stream prior to distillation. The insoluble solids were removed to clarify the fermentation broth. This reduces or prevents plugging of subsequent distillation equipment. Insoluble solids may be removed by any one or combination of a variety of solid-liquid separation techniques, including but not limited to centrifugation and filtration (including but not limited to ultrafiltration, microfiltration, or depth filtration), alone. Filtration may be selected using techniques known in the art. The soluble organic compounds can be removed by any number of known methods such as, but not limited to, ion exchange, physical adsorption, and the like.

An example of centrifugation is a continuous disk centrifuge. After centrifugation, it may be useful to add a polishing filtration step, such as dead-end filtration or cross-flow filtration, which may include the use of filtration aids such as diatomaceous earth or the like, or more preferably ultrafiltration or microfiltration. The ultrafiltration or microfiltration membrane may be, for example, a ceramic or polymeric material. An example of a polymeric Membrane is SelRO MPS-U20P (pH stabilized ultrafiltration Membrane) manufactured by Koch Membrane Systems, Inc. (Koch Membrane Systems, great Eat 850, Wilmington, Mass., USA). It is a commercially available polyethersulfone membrane with a molecular weight cut-off of 25,000 daltons, typically operating at pressures of 0.35MPa to 1.38MPa (maximum pressure of 1.55 MPa) and at temperatures up to 50 ℃. Alternatively, a filtration step such as ultrafiltration or microfiltration may be employed alone.

The resulting clarified DAS-containing fermentation broth or MAS-containing fermentation broth that is substantially free of microbial culture medium and other solids is transferred through a stream to a distillation apparatus.

The clarified distillation broth should contain an amount of DAS and/or MAS that constitutes at least a majority, preferably at least about 70wt.%, more preferably 80wt.% and most preferably at least about 90wt.% of all diammonium dicarboxylate salts in the broth. The DAS and/or MAS content in weight percent (wt.%) of the total dicarboxylate in the fermentation broth can be readily determined by High Pressure Liquid Chromatography (HPLC) or other known methods.

Water and ammonia are removed from the distillation apparatus as overhead distillate, and at least a portion of the water and ammonia are optionally recycled to the bioconversion vessel (or growth vessel operating in anaerobic mode) by means of a flow aid. Distillation temperature and pressure are not critical as long as the distillation is conducted in a manner that ensures that the overhead distillate of the distillation contains water and ammonia and the bottoms of the distillation comprises at least some DAS and at least about 20wt.% water. More preferred amounts of water are at least about 30wt.% and even more preferred amounts are at least about 40 wt.%. The rate of ammonia removal from the distillation step increases with increasing temperature and can also be increased by injecting steam (not shown) during distillation. The rate of ammonia removal during distillation can also be increased by performing the distillation under vacuum or by blowing the distillation apparatus with a non-reactive gas such as air, nitrogen, or the like.

The removal of water during the distillation step can be enhanced by using an organic entrainer such as toluene, xylene, cyclohexane, methylcyclohexane, methyl isobutyl ketone, heptane, and the like, provided that the bottoms contains at least about 20wt.% water. If the distillation is carried out in the presence of an organic agent capable of forming an azeotrope, which azeotrope consists of water and the organic agent, the distillation produces a biphasic bottoms comprising an aqueous phase and an organic phase, in which case the aqueous phase may be separated from the organic phase and the aqueous phase is used as the bottoms of the distillation. By-products such as succinamic acid, succinamide and succinimide are substantially avoided so long as the water content in the bottoms is maintained at a level of at least about 30 wt.%.

The preferred temperature for the distillation step is in the range of about 50 c to about 300 c, depending on the pressure. A more preferred temperature range is from about 90 c to about 150 c, which is dependent on pressure. Distillation temperatures of about 110 ℃ to about 140 ℃ are preferred. "distillation temperature" refers to the temperature of the bottoms (for batch distillation, this temperature can be the temperature when the last desired amount of overhead distillate is withdrawn).

The addition of a water-miscible organic solvent or ammonia separating solvent facilitates the removal of ammonia at various distillation temperatures and pressures as discussed above. Such solvents include aprotic solvents, dipolar solvents, oxygen-containing solvents capable of forming inert hydrogen bonds. Examples include, but are not limited to: diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol, sulfoxides such as dimethyl sulfoxide (DMSO), lactones such as gamma-butyrolactone (GBL), amides such as Dimethylformamide (DMF) and dimethylacetamide, sulfones such as dimethyl sulfone, sulfolane, polyethylene glycol (PEG), butoxytriethylene glycol, N-methyl pyrrolidone (NMP), ethers such as dioxane, and Methyl Ethyl Ketone (MEK), and the like.

The distillation may be carried out at atmospheric, sub-atmospheric or super-atmospheric pressure. The distillation may be a single stage flash distillation, a multi-stage distillation (i.e., a multi-stage tower distillation), or the like. Single stage flash evaporation may be carried out in any type of flash evaporator (e.g., wiped film evaporator, thin film evaporator, thermosiphon flash evaporator, forced circulation flash evaporator, and the like). The multistage distillation column can be realized by using trays, packing, and the like. The packing may be loose packing (e.g., Raschig rings, pall rings, and Bell saddles, etc.) or structured packing (e.g., Koch-Sulzer packing, Intelox packing, and Maillard packing (Mellapak), etc.). The trays can be of any design (e.g., sieve trays, valve trays, bubble cap trays, etc.). The distillation may be carried out in any number of theoretical stages.

If the distillation apparatus is a column, the configuration is not particularly critical and well-known rules can be used to design the column. The column can be operated in stripping mode, rectification mode or fractionation mode. The distillation can be carried out in batch mode or continuous mode. In the continuous mode, the fermentation broth is continuously fed to the distillation apparatus, and the overhead and bottoms are continuously removed from the apparatus as they are formed. The distillate from the distillation is an ammonia/water solution and the bottoms of the distillation, which may also contain other fermentation by-product salts (i.e., ammonium acetate, ammonium formate, ammonium lactate, etc.) and color bodies, are liquid aqueous solutions of MAS and DAS.

The bottoms of the distillation can be transferred by stream to a cooling device and cooled by conventional methods. The cooling technique is not critical. A heat exchanger (using heat recovery) may be used. The bottoms can be cooled to about 15 ℃ using a flash cooler. Cooling to <15 ℃ typically utilizes a chilled coolant, such as a glycol solution, or, less preferably, saline. A concentration step may be included prior to cooling to help increase product yield. Further, known methods can be employed to combine concentration and cooling, such as vacuum evaporation and employing heat removal methods using integral cooling jackets and/or external heat exchangers.

We have found that the presence of some DAS in the liquid bottoms helps to cause, on cooling, separation of the bottoms into a liquid portion in contact with a solid portion that is at least "substantially composed of" MAS (meaning that the solid portion is at least substantially pure crystalline MAS) by reducing the solubility of MAS in the DAS-containing liquid aqueous bottoms. Figure 4 shows the reduced solubility of MAS in 30wt% aqueous DAS solutions at different temperatures from 0 ℃ to 60 ℃. The upper curve shows that the MAS remains substantially soluble in water (i.e., about 20wt% in aqueous solution) even at 0 ℃. The lower curve shows that MAS is essentially insoluble in a 30wt% aqueous DAS solution at 0 ℃. Thus, studies have found that MAS can be more completely crystallized from an aqueous solution if some DAS is also present in the aqueous solution. The preferred concentration of DAS in such a solution is in the range of ppm (parts per million) to about 3 wt%. This allows crystallization of the MAS solid portion (i.e., formation of the solid portion of the bottoms of the distillation) at a higher temperature than would be required in the absence of the DAS.

When about 50% of the ammonia is removed from the DAS contained in the aqueous medium, depending on the operating temperature and operating pressure, the various succinates establish an equilibrium molar distribution of DAS: MAS: SA of about 0.1:0.8:0.1 over the pH range of 4.8 to 5.4. When the composition is concentrated and cooled, the MAS exceeds its solubility limit in water and crystallizes. When the MAS undergoes a phase transition to the solid phase, the liquid phase counter weight is newly established, thereby generating more MAS (DAS provides ammonium ions to SA). This allows more MAS to crystallize from solution and continue until a significant amount of SA is consumed and the pH tends to rise. When the pH value rises, the liquid phase distribution is favorable for DAS. However, because DAS is highly soluble in water, MAS continues to crystallize because MAS has a lower solubility than DAS. In fact, the liquid phase equilibrium and the solid-liquid equilibrium of the various succinate salts act as "pumps" for the crystallization of MAS, thereby enabling high yields of MAS crystals.

In addition to the cooling, evaporation or evaporative cooling described above, crystallization of MAS may also be achieved and/or promoted by the addition of an antisolvent. In this context, the antisolvent may generally be a solvent: is miscible with water but results in crystallization of the water soluble salt due to its lower solubility in the solvent (e.g., MAS). The solvent having an antisolvent effect on MAS may be alcohols (e.g., ethanol and propanol), ketones such as (methyl ethyl ketone), ethers (e.g., tetrahydrofuran), and the like. The use of anti-solvents is known and may be used in combination with cooling and evaporation or alone.

After cooling the distilled bottoms in the cooling unit, the distilled bottoms are fed by a stream to a separator to separate the solid part from the liquid part. Separation can be achieved by pressure filtration (e.g., using a Nutsche-type pressure filter or Rosenmond-type pressure filter), centrifugation, or the like. The resulting solid product can be recovered as a product and, if desired, dried by standard methods.

After separation, it may be desirable to treat the solid portion to ensure that no liquid portion remains on the surface of the solid portion. One way to minimize the amount of liquid fraction remaining on the surface of the solid fraction is to wash the separated solid fraction with water and dry the resulting washed solid fraction. A convenient way to wash the solid fraction is to use a so-called "basket centrifuge". A suitable basket centrifuge is commercially available from The Western Statesmachine Company, Hamilton, Ohio, USA.

The liquid portion of the bottoms of the distillation (i.e., the mother liquor) may contain the remaining dissolved MAS, any unconverted DAS, any fermentation byproducts (such as ammonium acetate, ammonium lactate, or ammonium formate), and other minor impurities. The liquid portion may be sent to a downstream device via a flow. In one example, the downstream apparatus may be an apparatus for forming a deicing agent, for example, by treating the mixture with an appropriate amount of potassium hydroxide to convert an ammonium salt to a potassium salt. The ammonia produced in this reaction can be recovered for reuse in the bioconversion vessel (or growth vessel operating in anaerobic mode). The resulting potassium salt mixture is valuable as a de-icing and anti-icing agent.

The mother liquor from the solids separation step may be recycled (or partially recycled) to the distillation unit by means of a flow to further enhance recovery of MAS and to further convert DAS to MAS.

The solid portion of the cooling induced crystallization is substantially pure MAS and is therefore useful for the known uses of MAS.

HPLC can be used to detect the presence of nitrogen-containing impurities such as succinamide and succinimide. The purity of MAS can be determined by elemental carbon and nitrogen analysis. Ammonia electrodes can be used to determine crude approximations of MAS purity.

Depending on the environment and various operating inputs, there are situations where the fermentation broth may be a clarified MAS-containing fermentation broth or a clarified SA-containing fermentation broth. In these cases, it may be advantageous to add MAS, DAS, SA, ammonia and/or ammonium hydroxide to these broths in order to produce substantially pure MAS. For example, the working pH of the fermentation broth can be determined such that the fermentation broth is a MAS-containing fermentation broth or a SA-containing fermentation broth. MAS, DAS, SA, ammonia and/or ammonium hydroxide are optionally added to these broths to help produce the substantially pure MAS described above. For example, the working pH of the fermentation broth may be adjusted so that the fermentation broth is a MAS-containing fermentation broth or a SA-containing fermentation broth. MAS, DAS, SA, aqueous ammonia and/or ammonium hydroxide may optionally be added to these broths to obtain a broth pH preferably less than 6 to facilitate the production of substantially pure MAS as described above. Further, MAS, DAS and/or SA from other sources may be added as desired. In one particular form, it is particularly advantageous to recycle MAS, DAS and water from the liquid bottoms resulting from the distillation step and/or the liquid portion from the separator into the fermentation broth. With respect to MAS-containing fermentation broths, such fermentation broths generally refer to fermentation broths that include MAS added and/or produced by bioconversion or other processes and possibly any number of other components (such as DAS and/or SA).

The solid portion can be converted to SA by removing ammonia. This can be done by the following steps. The solid portion (consisting essentially of MAS) resulting from any of the above-described conversion processes may be dissolved in water to produce an aqueous MAS solution. The solution is then distilled at a temperature and pressure sufficient to form an overhead that comprises water and ammonia, and a bottoms that comprises a major portion of SA, a minor portion of MAS, and water. The bottoms is cooled to separate into a liquid portion in contact with a solid portion consisting essentially of SA and substantially free of MAS. The solid portion can be separated from the second liquid portion and recovered as substantially pure SA (as determined by HPLC).

As described below and as shown in fig. 2 and 3, streams including SA, MAS, and/or DAS as described above may be converted into selected downstream products, such as nitrogen-containing compounds, including but not limited to DAB, SDN, DAM, and the like. In starting these processes, SA, MAS and/or DAS may typically be dissolved in water to form their aqueous solutions, which may be fed directly into a downstream reactor.

SA, MAS or DAS can be converted directly to SDN by dehydration or indirectly via intermediate DAM. Such dehydration may be effected thermally, enzymatically or in the presence of a catalyst. Thus, depending on whether the conversion to SDN is performed directly or indirectly, the appropriate temperature, pressure and catalyst are selected to achieve the appropriate degree of dehydration.

For example, the conversion may utilize a suitable dehydration catalyst, such as an acidic catalyst or a basic catalyst, including phosphates disclosed in patent US 4,237,067 and supported catalysts utilizing Ti, V, Hf or Zr on clay or alumina disclosed in patent US 5,587,498. For example, such catalysts are typically used at temperatures of 220 ℃ to 350 ℃ and pressures of 170psig to 600 psig.

Alternatively, dehydration can be achieved by heating, as disclosed in patent US 3,296,303, wherein the acid and ammonia source are dehydrated by heating at a pressure of 150psig to 200psig, at a temperature of 100 ℃ to 130 ℃, in the presence of a glycol solvent.

Thus, SA, MAS or DAS may be dehydrated directly to generate SDN or indirectly through intermediate DAM to generate SDN. Next, once SDN is prepared, SDN can be converted directly to an amine (e.g., DAB), or indirectly to DAB through an intermediate SAN.

For example, direct conversion from SDN to DAB can be achieved using any number of means, such as the means disclosed in patent US 6,376,714, wherein dinitriles are converted using a catalyst (e.g., Fe, Co, Ni, Rh, or Pd using Ru, Cr, or W to upgrade catalytic performance in the presence of hydrogen and an ammonia source at 300psig to 1500psig at a temperature of 50 ℃ to 150 ℃. The result is a high yield of diamine, in this case DAB.

Similarly, patent US 4,003,933 passes Co/ZrO at 1500psig at temperatures of 120 ℃ to 130 ℃₂A catalyst, using hydrogen to convert nitriles to amines. Other catalysts may include those located on TiO₂Or ZrO₂Fe, Rh, Ir and Pt above.

Indirect conversion of SDN to SAN can be achieved by selecting suitable hydrogenation conditions, such as those disclosed in U.S. Pat. No. 5,151,543, wherein nitriles are converted to aminonitriles, in this case SDN to SAN, at 250psig to 1000psig, at temperatures of 50 ℃ to 80 ℃, using a RANEY catalyst (e.g., Co or Ni to upgrade catalytic performance using Fe, Cr or Mo) with hydrogen and a source of ammonia.

Similarly, aminonitriles or diamino compounds can be co-prepared from dinitriles, as disclosed in patent US 7,132,562. US 7,132,562 uses Fe, Co, Ru, Ni catalysts modified with Cr, V, Ti or Mn at 3000 to 5000psig at temperatures of 50 to 250 ℃ to achieve high yields and selectivity to diamines or aminonitriles. The catalyst may also be modified with conventional P or N and HCN, or CO, as well as hydrogen and ammonia sources.

SA, MAS or DAS can also be converted directly to diamine (e.g., directly to DAB), or indirectly via DAM. For example, patent US 2,223,303 discloses the conversion of acids to amines by Cd or Cu catalysts at pressures of 10ATM to 300ATM, at temperatures of 200 ℃ to 450 ℃, using hydrogen and an ammonia source or an alkylamine. Similarly, patent US 3,579,583 discloses the use of hydrogen and an ammonia source at a pressure of 100ATM to 300ATM, at a temperature of 200 ℃ to 300 ℃, in Zn-Al₂O₃Or a Zn-Cr catalyst, to convert dicarboxylic acids to amines, especially to alkylamines.

Furthermore, patent US 4,935,546 discloses the use of a titanium oxide in TiO₂Or Al₂O₃The acid is converted to the amine using hydrogen and an ammonia source in the presence of a supported Co, Cu or Cr catalyst at a pressure of 20 bar to 150 bar at a temperature of 250 ℃ to 350 ℃.

Once the conversion to DAB and SAN has been completed, these compounds can also be converted to polyamide type compounds by any number of means known in the art. Representative examples include the following transformations. Polyamides can be prepared from aminonitriles (e.g., SAN). An example of this type of conversion can be found in patent US 5,109,104, which converts omega-aminonitriles in the presence of an oxidized phosphorus catalyst and water. This is typically accomplished in a multi-step conversion at a temperature of 200 ℃ to 330 ℃ at a pressure in the range of 250psig to 350 psig.

An alternative process is disclosed in patent US 6,958,381, wherein a starting monomer (e.g. SAN) can be polymerized to a polyamide in the presence of a chain regulator comprising a nitrile group and a functional group capable of forming a carboxamide group.

Polyamides can also be formed from diamines (e.g., DAB), wherein DAB is polymerized with dicarboxylic acids or esters to form a polyamide. Preferred dicarboxylic acids have C₄To C₁₂The chain length of (a). The dicarboxylic acid or ester may be an aromatic dicarboxylic acid or ester, or it may be an alkyl dicarboxylic acid.

The subject matter and content of the above-mentioned U.S. patents No. 4,237,067, No. 5,587,498, No. 3,296,303, No. 6,376,714, No. 4,003,933, No. 5,151,543, No. 7,132,562, No. 2,223,303, No. 3,579,583, No. 4,935,546, No. 5,109,104 and No. 6,958,381 are incorporated herein by reference.

Examples

The process is illustrated by the following non-limiting representative examples. In many embodiments, synthetic aqueous DAS solutions are used in place of the actual clarified DAS-containing fermentation broth. Other examples employ actual clarified DAS-containing fermentation broths.

Because of the solubility of typical fermentation byproducts in the actual fermentation broth in the process of the invention, the use of the synthesized DAS solution is considered a good model for the properties of the actual fermentation broth. The main by-products produced during fermentation are ammonium acetate, ammonium lactate and ammonium formate. If these impurities are present during the distillation step, they would not be expected to lose ammonia in large amounts and form free acids before all the DAS has been converted to MAS. This is because acetic, lactic, and formic acids are more acidic than the divalent acid radical of SA ((pKa = 5.48) — in other words, acetate, lactate, formate, and even hydrogen succinate have a weaker basicity than the succinate salt of the divalent anion.

Example 1

This example illustrates the conversion of a portion of DAS to MAS by distillation and recovery of MAS solid from the distilled bottoms liquid by cooling-induced crystallization.

A 500ml three-neck round bottom flask was fitted with a thermometer and Dean Stark trap with a reflux condenser on top. The outlet of the reflux condenser was led to a gas washing bottle containing 100 g of 1.4M acetic acid solution. The flask was charged with 400 grams of 10% aqueous DAS (pH 8.5). The contents of the flask were stirred with a magnetic stirrer and heated by a heating mantle to distill off 320.6 grams of distillate (aqueous ammonia solution) which was removed through a Dean Stark trap. Analysis of this distillate showed that about 20% of the contained ammonia had been removed from the charged DAS during distillation (i.e., the salts in the bottoms liquid were about 40% MAS and about 60% DAS). Only trace amounts of ammonia were present in the scrubbing cylinder. When the last drop distilled off, the final temperature of the flask was 110 ℃. The residue (bottom residue liquid) (73.4 grams, about 53% water) in the flask was placed in a flask and allowed to cool to room temperature overnight. When cooled to room temperature, white needle-like MAS was formed. The white solid was isolated by vacuum filtration yielding 14 grams of wet crystals (solid portion) and 56 grams of mother liquor (liquid portion). A portion (7 grams) of the wet crystals were dried overnight in a vacuum oven to yield 6 grams of dry solid containing 0.4% water as determined by Karl-Fisher analysis. Analysis of the solid portion by HPLC showed that the solid portion contained no nitrogen-containing non-MAS impurities (e.g., succinimide and succinamide).

Example 2

This example illustrates mother liquor recovery.

A 1L round bottom flask was charged with 800 grams of the synthesized 4.5% DAS solution and then a distillation head was attached to the flask. The contents of the flask were distilled at atmospheric pressure, leaving 67 grams of residue (bottoms liquid) in the flask. The bottoms liquid contains about 45% water. Ammonia analysis of the distillate showed that the first distillation cycle removed about 29% of the ammonia, forming a mixture of DAS and MAS with a molar ratio of 42/58. The residue (bottom residue liquid) was then removed from the flask and placed in a beaker equipped with a water bath. The contents of the beaker were cooled to 20 ℃ with stirring. Once the residue reached 20 ℃, a small amount of MAS crystals were used as seeds and stirred for 30 minutes. The temperature of the water bath was then lowered to 15 ℃ and held for 30 minutes. The temperature of the water bath was then reduced to 10 ℃ and held for 30 minutes. The temperature of the water bath was then reduced to 5 ℃ for 30 minutes and finally to 0 ℃ for 30 minutes. Next, the slurry (consisting of a solid part and a liquid part) was rapidly filtered using a pre-cooled sintered glass filter funnel and a vacuum flask. The solid was dried in a vacuum oven yielding 13.9 grams of dried MAS solid. The mother liquor (liquid portion, 47.2 g) was then mixed with 800 g of the synthesized 4.5% DAS solution and distilled, leaving 86.6 g of residue (bottoms liquid). In the second distillation (i.e., mother liquor recovery scheme), approximately 28% of the ammonia is removed from the current total amount of DAS. Then, the residue (bottom residue liquid) was cooled (crystallized) in a similar manner. However, the solution became cloudy at 46 ℃, so it was seeded at 46 ℃ and slowly cooled to room temperature overnight with stirring. The following day, the temperature was slowly ramped down to 0 ℃ with a 5 ℃ ramp down. The slurry (solid and liquid) was filtered in the same manner as before and the solids were dried, yielding 23.5 grams of MAS solids. This corresponds to the recovery of about 75% of the SA counterpart in 800 grams of fresh DAS solution that was distilled. The solids recovered from the first cycle was 95% MAS (about 5% water). In the second cycle, the solids were 97% MAS (about 3% water). The mother liquor from the second cycle contained 28.8% of the SA counterpart (i.e. as SA salt).

Example 3

This example illustrates that the solid portion of the bottoms of the distillation after cooling is free of amide and imide.

A1L round bottom flask was charged with 800 grams of the synthesized 4.5% DAS solution. The flask was equipped with five trays 1 "Oldershaw section (a five tray 1" Oldershaw section) with a distillation head at the top. The distillate was collected in an ice cold receiver. The contents of the flask were heated using a heating mantle and stirred using a magnetic stirrer. The contents of the flask were distilled to give 721.1 grams of overhead and 72.2 grams of liquid residue in the flask (i.e., bottoms of the distillation). Ammonia distillate was titrated to give an ammonia content of 0.34% (i.e., about 55% of DAS converted to MAS). The hot distillation bottoms (approximately 47% salt solution of DAS and MAS) were then placed in a 125 ml erlenmeyer flask and slowly cooled to room temperature overnight with stirring. The following morning, the cloudy solution was cooled to 15 ℃ and held for 60 minutes, then cooled to 10 ℃ and held for 60 minutes, and finally cooled to 5 ℃ and held for 60 minutes with stirring. The resulting white slurry was filtered to obtain 12.9 g of wet crystals and 55.3 g of mother liquor. The crystals were dissolved in 25.8 g of distilled water. HPLC analysis of the crystal solution showed that no amide or imide was detected. However, HPLC analysis of the mother liquor showed trace amounts of succinamic acid, but no succinamide or succinimide was detected.

Example 4

This example produced a solid portion of the cooled distillation bottoms consisting essentially of MAS and substantially free of DAS.

A1L three-necked round bottom flask was fitted with an addition funnel and a 1 "five-plate Oldershaw column (1" five tray Oldershaw column) with a distillation head at the top. An ice-cooled receiver was used to collect the distillate. The flask was charged with 800 grams of the synthesized 4.5% DAS solution. The contents of the flask were heated with a heating mantle and stirred with a magnetic stirrer. Distillation was started. As distillation occurred, an additional 1600 grams of 4.5% DAS solution was slowly added to the flask at the same rate as the distillate was removed. A total of 2135 grams of distillate was taken as overhead. Titration measurements of the distillate indicated a 0.33% ammonia solution in the overhead. The hot aqueous distillation bottoms (253.8 g) were removed from the flask and placed in an erlenmeyer flask. The distillation bottoms were slowly cooled to room temperature overnight with stirring. Seed crystals were added to the contents of the flask and stirred for 30 minutes. The slurry was then cooled to 15 ℃ and held for 60 minutes, then cooled to 10 ℃ and held for 60 minutes, and finally cooled to 5 ℃ and held for 60 minutes, all cooling being accompanied by stirring. The slurry was cold filtered and the solids (i.e., solid portion) were washed three times with a cold (about 5 ℃) portion of about 20g of 20% sodium chloride solution to remove the mother liquor (i.e., liquid portion). Several minutes of air was pumped through the filter cake to remove as much liquid as possible. The solid was then dried in a vacuum oven at 75 ℃ for 1 hour, yielding 7.2 g of white crystals. Analysis of the solid carbon and nitrogen showed a carbon to nitrogen atomic ratio of 4.06 (i.e., a 1.01 ammonia to SA ratio, or about 99% MAS). The failure to obtain a ratio of 1.00 is believed to be due to incomplete washing of the solids.

Example 5

This example illustrates the effect of solvent on ammonia expulsion from aqueous DAS solutions. The 5 th experiment is a control experiment in which no solvent is present.

The external neck of a 1L three-necked round bottom flask was equipped with a thermometer and stopper. The middle neck was equipped with five trays 1 "oldershake. The top of the Oldenstedt section has a distillation head. An ice-cold 500mL round bottom flask was used as receiver for the distillation head. A 1L round bottom flask was charged with distilled water, solvent tested, SA and concentrated ammonium hydroxide solution. The contents were stirred with a magnetic stirrer to dissolve all solids. After the solids dissolved, the contents were heated with a heating mantle to distill off 350g of distillate. The distillate was collected in an ice-cold 500mL round bottom flask. The flask temperature was recorded as the last drop of distillate was collected. The contents of the flask were allowed to cool to room temperature and the weight of the residue and the weight of the distillate were recorded. Next, the ammonia content of the distillate was determined by titration. The results are reported in table 1.

TABLE 1

Example 6

This example produces a solid portion from the cooled distillation bottoms that consists essentially of SA and is substantially free of MAS.

A 300 ml Parr autoclave was charged with 80 g of synthesized MAS and 120 g of water. The autoclave was sealed and the contents were stirred and heated to about 200 ℃ under autogenous pressure of about 190 psig. Once the contents reached this temperature, water was fed into the autoclave at a rate of about 2 grams per minute and steam was removed from the autoclave at a rate of about 2 grams per minute using a back pressure regulator. The vapor leaving the autoclave was condensed and collected in a receiver. The autoclave was operated under these conditions until a total of 1020 g of water was fed and a total of 1019 g of distillate was collected. The distillate was titrated to obtain the ammonia content (0.29% ammonia by weight). This translates into: about 29% of the MAS is converted to SA. The contents of the autoclave (194.6 g) were partially cooled and removed from the reactor. The slurry was stirred in an erlenmeyer flask at room temperature overnight. The slurry was then filtered and the solids were rinsed with 25 grams of water. The moist solid was dried in a vacuum oven at 75 ℃ for 1 hour to give 9.5 g of SA product. Analysis by an ammonium ion electrode showed 0.013mmol ammonium ions per gram of solid. HPLC analysis indicated the solid to be SA with 0.8% succinamic acid impurity.

Example 7

This example uses a clarified DAS-containing fermentation broth obtained from a fermentation broth containing the E.coli strain ATCC PTA-5132. This example produced a solid portion of the cooled distillation bottoms consisting essentially of MAS and substantially free of DAS.

A1L three-necked round bottom flask was fitted with an addition funnel and a 1 "five-plate Oldershaw. The top of the Oldenstaedtia column is provided with a distillation head. An ice-cooled receiver was used to collect the distillate. The flask was charged with 800 grams of a clarified DAS-containing broth containing 4.4% DAS, 1% ammonium acetate, 0.05% ammonium formate and 0.03% ammonium lactate. The contents of the flask were heated with a heating mantle and stirred with a magnetic stirrer. Distillation was started. During the distillation run, an additional 2200 grams of broth was slowly added to the flask at the same rate that distillate was removed. A total of 2703 grams of distillate was withdrawn as overhead. Titration of the distillate indicated a 0.28% ammonia solution in the overhead. An aqueous solution of the hot distillation bottoms (269.7 g) was removed from the flask and placed in an erlenmeyer flask. The distillation bottoms were allowed to cool slowly to room temperature while stirring overnight. The next day, seed crystals were added to the contents of the flask and stirring was carried out for 30 minutes. The slurry was then cooled to 15 ℃ and held for 30 minutes, then cooled to 10 ℃ and held for 30 minutes, and finally cooled to 5 ℃ and held for 30 minutes, all with stirring during cooling. The slurry was cold filtered and air was pumped to the filter cake for several minutes to remove as much liquid as possible. A light brown solid (72.5 g) and a dark brown mother liquor (188.4 g, pH 6.4) were obtained. The solid was recrystallized to remove mother liquor by dissolving the solid in 72 grams of water at 50 ℃. The solution was then allowed to cool slowly to room temperature overnight with stirring. The next day, seed crystals were added to the contents of the flask and stirring was carried out for 30 minutes. The slurry was then cooled to 15 ℃ and held for 30 minutes, then cooled to 10 ℃ and held for 30 minutes, and finally cooled to 5 ℃ and held for 30 minutes, all with stirring during cooling. The slurry was cold filtered and the filter cake was pumped with air for a few minutes to remove as much liquid as possible, yielding 110 grams of brown mother liquor (pH 5.0). The solid was then dried in a vacuum oven at 75 ℃ for 1 hour to give 24 g of off-white crystals. Carbon and nitrogen analysis of the solids showed a carbon to nitrogen molar ratio of 4.04 (i.e., ammonia to SA ratio of 1.01 or about 99% MAS). HPLC analysis indicated that MAS contained 0.07% succinamic acid, but no succinamide, succinimide, or acetate salts were detectable. In other words, the MAS contains no DAS and is essentially pure MAS.

Example 8

This example uses MAS obtained from fermentation of a fermentation broth containing the E.coli strain ATCC PTA-5132. This example produces a solid portion from the cooled distillation bottoms that consists essentially of SA and is substantially free of MAS.

A 300 ml Parr autoclave was charged with 80 grams of MAS taken over the fermentation broth and 120 grams of water. The autoclave was sealed and the contents were stirred and heated to about 202 ℃ under autogenous pressure of about 205 psig. Once the contents reached this temperature, water was fed into the autoclave at a rate of about 2 grams per minute and steam was removed from the autoclave at a rate of about 2 grams per minute using a back pressure regulator. The vapor leaving the autoclave was condensed and collected in a receiver. The autoclave was operated under these conditions until a total of 905 grams of water was fed and a total of 908 grams of distillate was collected. The distillate was titrated to obtain the ammonia content (0.38% ammonia by weight). This translates into: about 34% of the MAS is converted to SA. The contents of the autoclave (178.2 grams) were partially cooled and removed from the reactor. The slurry was stirred in an erlenmeyer flask at room temperature overnight. The slurry was then filtered and the solids were rinsed with 25 grams of water. The moist solid was dried in a vacuum oven at 75 ℃ for 1 hour to give 8.5 g of SA product. Analysis by an ammonium ion electrode showed 0.027mmol of ammonium ion per gram of solid. HPLC analysis indicated the solid to be SA with 1.4% succinamic acid and 0.1% succinamide impurity.

Example 9

This example uses an ammonia releasing solvent to aid in deamination. This example produces a solid portion from the cooled distillation bottoms that consists essentially of SA and is substantially free of MAS.

A 500ml round bottom flask was charged with 29 grams MAS solid, 51 grams water, and 80 grams triethylene glycol dimethyl ether. The flask was fitted with a five tray 1 "glass Oldershaw section with a distillation head at the top. An addition funnel containing 2500 grams of water was also attached to the flask. The flask was stirred with a magnetic stirrer and heated with a heating mantle. The distillate was collected in an ice cold receiver. When distillate began to appear, water in the addition funnel was added to the flask at the same rate as the distillate was removed. A total of 2491 g of distillate were removed. The distillate contained 2.3 grams of ammonia as determined by titration measurements. This means that about 63% of the MAS is converted to SA. The residue in the flask was then placed in an erlenmeyer flask and cooled to-5 ℃ with stirring. After stirring for 30 minutes, the slurry was filtered while cooling to give 15.3 g of a solid. The solid was dissolved in 15.3 grams of hot water and then cooled in an ice bath with stirring. The cold slurry was filtered and the solid was dried in a vacuum oven at 100 ℃ for 2 hours to give 6.5 g of succinic acid. HPLC analysis indicated the solid to be SA with 0.18% succinamic acid.

Example 10

This example uses an ammonia releasing solvent to aid in deamination. This example produces a solid portion of the cooled distillation bottoms that consists essentially of MAS and is substantially free of DAS.

A500 ml round bottom flask was charged with 80 grams of 36% aqueous DAS and 80 grams of triethylene glycol dimethyl ether. The flask was fitted with a five tray 1 "glass Oldershaw section with a distillation head at the top. An addition funnel containing 700 grams of water was also attached to the flask. The flask was stirred with a magnetic stirrer and heated with a heating mantle. The distillate was collected in an ice cold receiver. When distillate began to appear, water in the addition funnel was added to the flask at the same rate as the distillate was removed. A total of 747 grams of distillate was removed. The distillate contained 3.7 grams of ammonia as determined by titration measurements. This means that about 57% of the ammonia is removed. In other words, all DAS is converted to MAS, and about 14% of the MAS is further converted to SA. Then, the residue in the flask was placed in an erlenmeyer flask and cooled to 5 ℃ with stirring. After stirring for 30 minutes, the slurry was filtered while cooling and the solid was dried in a vacuum oven at 100 ℃ for 2 hours to give 10.3 g of MAS. Analysis indicated the solid to be MAS with 0.77% succinamic acid and 0.14% succinimide.

Example 11

This example illustrates the use of azeotropic solvents, particularly to separate MAS from other by-products in the fermentation broth.

A500 mL three necked round bottom flask was equipped with a thermometer, 250mL addition funnel, and Dean Stark trap with a reflux condenser on top. The flask was charged with 100 grams of toluene and 100 grams of about 9% DAS fermentation broth (which also contained about 1% combined ammonium acetate and ammonium formate). The addition funnel was charged with 250 grams of 9% diammonium succinate broth. The contents of the flask were stirred with a magnetic stirrer and heated to boiling with a heating mantle. The contents of the addition funnel were slowly added to the flask, the toluene-water azeotrope was allowed to enter the Dean Stark trap by distillation, and the toluene was returned to the flask. After the entire contents of the addition funnel had been added (at essentially the same rate as the distillate), the contents were further refluxed until a total of 277.5 grams of aqueous phase was collected from the Dean Stark trap. The contents of the flask were removed while the flask was hot and the two phases were separated in a warm separatory funnel. The aqueous phase was cooled in an ice bath with stirring. The resulting solid was recovered by filtration using a sintered glass funnel. The mother liquor was dark brown and the filtered solid was off-white. The solid was dried in a vacuum oven and analyzed by HPLC. The dry solids (5.7 grams) were about 96% monoammonium succinate and about 1% ammonium acetate with the balance water.

Example 12

An 8 inch length of 1.5 "316 SS Schedule 40 tube packed with 316 SS Propak packing was used to make the pressurized distillation column. The bottom of the column was equipped with a submerged heater to act as a reboiler. Nitrogen was injected into the reboiler through a needle valve to pressurize. The top of the column had a total take-off line leading to a 316 SS shell and tube condenser with a receiver. The receiver is equipped with a pressure gauge and a back pressure regulator. Material was removed from the top receptacle by air blowing through a needle valve. The preheated feed is injected into the column at the top of the packing by means of a pump. Preheated water was also injected into the reboiler via a pump. The column was operated at a pressure of 30psig, which provided a column temperature of 137 ℃. The top of the column was fed with a solution of the synthesized 10% DAS at a rate of 5mL/min and water at a rate of 5mL/min to the reboiler. The overhead rate was 8mL/min and the residue rate was 2 mL/min. Titration of the distillate against ammonia indicated that about 47% of the ammonia was removed in the distillate (i.e., conversion to MAS is about 94%). The residue liquid was about 20% MAS, and HPLC analysis of the residue indicated about 3% ineffective succinamic acid.

Example 13

A portion (800 grams) of the residue from example 12 was concentrated to about 59% MAS solution by batch distillation (i.e., 530 grams of water distilled off). The residue was then cooled to 5 ℃ with stirring. The resulting slurry was filtered and the solids were dried in a vacuum oven at 75 ℃ for 1 hour to yield 52.5 grams of MAS solid (i.e., about 32% recovery). HPLC analysis indicated that the solid contained 0.49% succinamic acid and no succinimide.

Example 14

A second portion (3200 grams) of the pressure column residue from example 12 was placed in an evaporative crystallizer and concentrated to about 72% MAS by distilling 2312 grams of water under vacuum and at 60 ℃. The resulting hot slurry was centrifuged and the recovered solid was dried in a vacuum oven at 75 ℃ for 1 hour to yield 130.7 grams of MAS solid. The mother liquor from the centrifugation step was cooled to room temperature to form a second crop of crystals. The slurry was filtered and the recovered solid was dried under vacuum at 75 ℃ to give 114.8 g of MAS solid. Based on the concentration of succinate provided to the crystallizer, a 20% recovery and an 18% recovery (i.e., an overall recovery of 38%) were achieved for the first and second batches of crystals, respectively. HPLC analysis of the two batches of solid indicated that the first crystals were not detectable for succinamic acid and succinimide, while the second crystals had 0.96% for succinamic acid and 0.28% for succinimide.

Comparative example 1

This example illustrates that atmospheric distillation of an aqueous MAS solution removes very little ammonia when triethylene glycol dimethyl ether is not present.

A 500ml round bottom flask was charged with 30 grams MAS solid and 120 grams water. The flask was fitted with a five tray 1 "Oldershaw section with a distillation head at the top. An addition funnel containing 600 grams of water was also attached to the flask. The flask was stirred with a magnetic stirrer and heated with a heating mantle. The distillate was collected in an ice cold receiver. When distillate began to appear, water in the addition funnel was added to the flask at the same rate as the distillate was removed. A total of 606 grams of distillate was removed. The distillate contained 0.15 grams of ammonia as determined by titration measurements. This means that 4% of the MAS is converted to SA.

Comparative example 2

This example illustrates the reduction in ammonia removal for DAS when triethylene glycol dimethyl ether is not present.

A500 ml round bottom flask was charged with 80 grams of 36% aqueous DAS and 80 grams of water. The flask was fitted with a five tray 1 "Oldershaw section with a distillation head at the top. An addition funnel containing 1200 grams of water was also attached to the flask. The flask was stirred with a magnetic stirrer and heated with a heating mantle. The distillate was collected in an ice cold receiver. When distillate began to appear, water in the addition funnel was added to the flask at the same rate as the distillate was removed. A total of 1290 g of distillate were removed. The distillate contained 2.2 grams of ammonia as determined by titration measurements. This means that about 44% of the DAS is converted to MAS.

Although the method of the present invention has been described in connection with specific steps and forms thereof, it should be understood that a wide range of equivalents may be substituted for the specific elements and steps described herein without departing from the spirit and scope of the invention as described in the appended claims.

Claims (19)

1. A process for the preparation of a nitrogen-containing compound, the process comprising the steps of:

(a) providing a clarified DAS-containing fermentation broth;

(b) distilling the broth to form an overhead that comprises water and ammonia and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water;

(c) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS;

(d) separating at least a portion of the solid portion from the liquid portion;

(e) (1) contacting the solid portion with hydrogen and optionally with an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or

(2) Dehydrating at least a portion of the solid portion to produce SDN; or

(3) Dehydrating at least a portion of the solid portion to produce a succinamide DAM; and

(f) recovering the DAB, the SDN or the DAM.

2. A process for the preparation of a nitrogen-containing compound, the process comprising the steps of:

(a) providing a clarified DAS-containing fermentation broth;

(b) distilling the broth to form a first overhead that comprises water and ammonia, and a first liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water;

(c) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS;

(d) separating the solid portion from the liquid portion;

(e) recovering the solid portion;

(f) dissolving the solid portion in water to produce an aqueous MAS solution;

(g) distilling the aqueous MAS solution at a temperature and pressure sufficient to form a second overhead that includes water and ammonia, and a second bottoms that includes a major portion of Succinic Acid (SA), a minor portion of MAS, and water;

(h) cooling and/or evaporating the second bottoms to cause the second bottoms to separate into a second liquid portion in contact with a second solid portion, preferably consisting essentially of SA and substantially free of MAS;

(i) separating at least a portion of the second solid portion from the second liquid portion;

(j) (1) contacting the second solid portion with hydrogen and an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or

(2) Dehydrating at least a portion of the second solid portion to produce SDN; or

(3) Dehydrating at least a portion of the second solid portion to produce a DAM; and

(k) recovering the DAB, the SDN or the DAM.

3. A process for the preparation of a nitrogen-containing compound, the process comprising the steps of:

(a) providing a clarified MAS-containing fermentation broth;

(b) optionally MAS, DAS, SA, NH₃And/or NH₄ ⁺Adding to the fermentation broth to preferably maintain the pH of the fermentation broth below 6;

(c) distilling the broth to form an overhead that comprises water and optionally ammonia, and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water;

(d) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS;

(e) separating at least a portion of the solid portion from the liquid portion;

(f) (1) contacting the solid portion with hydrogen and optionally with an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or

(2) Dehydrating at least a portion of the second solid portion to produce SDN; or

(3) Dehydrating at least a portion of the second solid portion to produce a DAM; and

(g) recovering the DAB, the SDN or the DAM.

4. A process for the preparation of a nitrogen-containing compound, the process comprising the steps of:

(a) providing a clarified MAS-containing fermentation broth;

(b) optionally MAS, DAS, SA, NH₃And/or NH₄ ⁺Adding to the fermentation broth to preferably maintain the pH of the fermentation broth below 6;

(c) distilling the broth to form an overhead that comprises water and optionally ammonia, and a liquid bottoms that comprises MAS, at least some DAS, and at least about 20wt% water;

(d) cooling and/or evaporating the bottoms, and optionally adding an antisolvent to the bottoms, to attain a temperature and composition sufficient to cause the bottoms to separate into a DAS-containing liquid portion and a MAS-containing solid portion that is substantially free of DAS;

(e) separating the solid portion from the liquid portion;

(f) recovering the solid portion;

(g) dissolving the solid portion in water to produce an aqueous MAS solution;

(h) distilling the aqueous MAS solution at a temperature and pressure sufficient to form a second overhead that includes water and ammonia, and a second bottoms that includes a major portion of SA, a minor portion of MAS, and water;

(i) cooling and/or evaporating the second bottoms to separate the second bottoms into a second liquid portion in contact with a second solid portion, preferably consisting essentially of SA and substantially free of MAS;

(j) separating at least a portion of the second solid portion from the second liquid portion;

(k) (1) contacting the solid portion with hydrogen and an ammonia source in the presence of at least one hydrogenation catalyst to produce DAB; or

(2) Dehydrating at least a portion of the solid portion to produce SDN; or

(3) Dehydrating at least a portion of the solid portion to produce a DAM; and

(l) Recovering the DAB, the SDN or the DAM.

5. The process of any of claims 1-4, further comprising polymerizing the DAB with a dicarboxylic acid or ester to form a polyamide.

6. The process of any of claims 1-4, further comprising contacting the SDN with hydrogen and ammonia in the presence of a hydrogenation catalyst to produce DAB.

7. The process of claim 6, further comprising polymerizing the DAB with a dicarboxylic acid or ester to form a polyamide.

8. The process of any one of claims 1 to 4, further comprising contacting the SDN with hydrogen and ammonia in the presence of a hydrogenation catalyst to produce a composition comprising succinic aminonitrile SAN.

9. The method of claim 8, further comprising polymerizing the SAN to form a polyamide.

10. The process of claim 8, further comprising contacting the SAN with hydrogen and ammonia in the presence of a hydrogenation catalyst to produce DAB.

11. The process of claim 10, further comprising polymerizing the DAB with a dicarboxylic acid or ester to form a polyamide.

12. The process of any one of claims 1 to 4, further comprising dehydrating the DAM to produce SDN.

13. The process of claim 12, further comprising contacting the SDN with hydrogen and ammonia in the presence of a hydrogenation catalyst to produce DAB.

14. The process of claim 13, further comprising polymerizing the DAB with a dicarboxylic acid or ester to form a polyamide.

15. The process of claim 12, further comprising contacting the SDN with hydrogen and ammonia in the presence of a hydrogenation catalyst to produce a composition comprising SAN.

16. The method of claim 15, further comprising polymerizing the SAN to form a polyamide.

17. The process of claim 15, further comprising contacting the SAN with hydrogen and ammonia in the presence of a hydrogenation catalyst to produce DAB.

18. The process of claim 17, further comprising polymerizing the DAB with a dicarboxylic acid or ester to form a polyamide.

19. The process according to any one of claims 1 to 4, wherein the distillation is carried out in the presence of an ammonia separating solvent which is at least one selected from the group consisting of diglyme, triglyme, tetraglyme, sulfoxides, amides, sulfones, Polyethyleneglycol (PEG), butoxytriglycol, N-methylpyrrolidone (NMP), ethers, and Methyl Ethyl Ketone (MEK); alternatively, the distillation is carried out in the presence of a water entrainer which is at least one selected from the group consisting of toluene, xylene, methylcyclohexane, methyl isobutyl ketone, hexane, cyclohexane and heptane.