A method for extracting long-chain dibasic acid from fermentation broth

Abstract

The present invention provides a method for extracting and purifying a long-chain dibasic acid from a fermentation broth, the method comprising: (1) controlling the pH of the fermentation broth to be ≤5 and the density to be 0.9 to 1.16 g / cm 3 , obtaining a first solid-liquid mixture; (2) centrifuging the first solid-liquid mixture to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture; (3) separating the long-chain dibasic acid from the second solid-liquid mixture. This method is simple to operate, requires less equipment and investment, and has high processing efficiency. The fermentation broth is centrifuged to remove most of the bacteria and impurities. The obtained product has high purity and high product yield.

Description

Technical Field

[0001] The invention relates to a method for extracting long-chain dibasic acid from fermentation broth. Background Art

[0002] Long chain dicarboxylic acids (LCDA), the general structural formula of which is: HOOC-(CH2) m -COOH (n = 8-16), referred to as DCn, n = 10 ~ 18, is an important organic intermediate, which is widely used in chemical industry, light industry, pesticides, medicine, new materials and other fields. At present, the most common method for preparing long-chain dibasic acids is to obtain them by fermenting long-chain alkanes, fatty acids, and fatty acid derivatives under specific strains.

[0003] At present, the production process of long-chain dibasic acids prepared by biological fermentation is relatively complicated. The fermentation broth often needs to be dissolved by alkali for many times, decolorized, and filtered to remove impurities such as cell tissue, protein, and pigment of the fermentation microorganisms, and then acid is added to crystallize the long-chain dibasic acid. On the one hand, a large amount of alkali and acid is consumed, and the salt content in the crystallization mother liquor is too high, which requires complex post-treatment to meet the emission standards. On the other hand, multiple decolorization and filtering operations will extend the production cycle to a certain extent, and may also cause a loss in product yield.

[0004] For example, Chinese patent CN1053470C discloses the following method for preparing long-chain dibasic acid: add alkali to the fermentation broth of tridecanedioic acid (DC13) to adjust the pH value to 10-12, heat the fermentation broth to 85-90°C, demulsify, in some cases, recycle the alkanes remaining in the upper layer, collect the clarified solution of the middle layer, and the bacterial layer can be reprocessed to obtain a second clear liquid, or directly centrifuged or filtered. Then, the clear liquid is decolorized by activated carbon at 85-90°C to remove the activated carbon. HCl or H2SO4 is further added to the decolorized solution to adjust the pH value so that the dibasic acid precipitates and crystallizes to obtain a long-chain dibasic acid product.

[0005] For a fermentation broth with a pH value of 7 to 8, the alkanes and bacteria are first removed, and a large amount of alkali is added to the fermentation broth, such as adjusting the pH of the fermentation broth to about pH 10 to 12. After the acidification is completed, an excess of alkali is also used to neutralize the corresponding excess acid. As a result, excess salt is generated and discharged into the wastewater.

[0006] For example, Chinese patent CN104693018A discloses a demulsification method, in which the fermentation broth of long-chain dibasic acid is directly acidified, that is, the precipitated long-chain dibasic acid and bacterial cells are separated from the fermentation broth, dried, and then extracted and purified by an organic solvent to remove the bacterial cells. The key problem of this method is that impurities will dissolve in the organic solvent, resulting in reduced product purity and yield. Summary of the invention

[0007] The present invention provides a method for extracting a long-chain dibasic acid from a fermentation broth, the method comprising the following steps:

[0008] (1) Control the pH of the fermentation liquid to ≤5 and the density to 0.9-1.16 g / cm 3 , obtaining a first solid-liquid mixture;

[0009] (2) centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture;

[0010] (3) Separating a long-chain dibasic acid from the second solid-liquid mixture.

[0011] Furthermore, the method comprises the following steps:

[0012] (1) Control the pH of the fermentation liquid to ≤5 and the density to 0.9-1.16 g / cm 3 , after cooling treatment, a first solid-liquid mixture is obtained, wherein the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 to 1000 μm;

[0013] (2) centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture;

[0014] (3) Separating a long-chain dibasic acid from the second solid-liquid mixture.

[0015] After centrifugation, most of the long-chain dibasic acid enters the second solid-liquid mixture (i.e., the heavy phase after centrifugation), and most of the bacteria enter the third solid-liquid mixture (i.e., the light phase after centrifugation) to be separated from the long-chain dibasic acid. The content (g) of the long-chain dibasic acid in the third solid-liquid mixture is less than the content (g) of the long-chain dibasic acid in the second solid-liquid mixture.

[0016] According to some embodiments of the present invention, the recovery rate of the bacteria in the third solid-liquid mixture is 75-95%, for example 80wt%, 85wt%, 88wt%, 90wt%.

[0017] For the method described in any one of the present invention, the content of long-chain dibasic acid in the second solid-liquid mixture is ≥40wt%, further 40-70wt%, for example, 43wt% or more, 48wt% or more, 50wt% or more, 55wt% or more, 57wt% or more, 65wt% or more.

[0018] For any of the methods of the present invention, the centrifugal equipment includes but is not limited to a hydrocyclone, a horizontal sedimentation centrifuge, a siphon scraper centrifuge, or any combination thereof. The centrifugal speed is 500 to 5000 rpm, further 1500 to 2900 rpm, such as 1800 rpm, 2000 rpm, 2500 rpm, 2700 rpm.

[0019] For any of the methods of the present invention, the centrifugal device is a horizontal decanter centrifuge, and the drum speed of the horizontal decanter centrifuge is 1500-4500 rpm, further 1500-2900 rpm, such as 1800 rpm, 2000 rpm, 2500 rpm, 2700 rpm.

[0020] According to some embodiments of the present invention, before cooling in step (1), the fermentation liquid is kept at 92°C to 103°C for 10 to 120 min, further for 20 to 120 min, for example, 20 min, 30 min, 60 min, 90 min, 100 min, 110 min. The keeping temperature is, for example, 94°C, 96°C, 98°C, 100°C, 101°C, 102°C.

[0021] According to some embodiments of the present invention, the method comprises the following steps:

[0022] (1) Control the pH of the fermentation liquid to ≤5 and the density to 0.9-1.16 g / cm 3 , keeping the fermentation liquid at 92° C. to 103° C. for 10 to 120 minutes, and cooling the mixture to obtain a first solid-liquid mixture, wherein the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 to 1000 μm;

[0023] (2) centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture;

[0024] (3) Separating a long-chain dibasic acid from the second solid-liquid mixture.

[0025] According to some embodiments of the present invention, the density of the fermentation liquid in step (1) is 0.95-1.12 g / cm 3 , for example 1.10 g / cm 3 , further 0.98~1.06g / cm 3 , for example 0.99 g / cm 3 , 1.00g / cm 3 , 1.02g / cm 3 , 1.04g / cm 3, 1.05g / cm 3 The method for controlling the density of the fermentation broth may be a dilution process or a concentration process commonly used in the art, or adding an inorganic salt or an inorganic salt solution to the fermentation broth. For example, when the density of the fermentation broth is low, an inorganic salt or an inorganic salt solution may be added to increase the density of the fermentation broth. The inorganic salt may be, for example, sodium sulfate.

[0026] According to some embodiments of the present invention, in step (1), the concentration of the long-chain dicarboxylic acid in the fermentation broth is controlled to be 5 to 15 wt %, further to 6 to 12 wt %, and further to 6 to 10 wt %. Before the cooling treatment in step (1), the fermentation broth may or may not be subjected to concentration adjustment, thereby controlling the concentration of the long-chain dicarboxylic acid in the fermentation broth to be within the above range. The method for adjusting the concentration may be, for example, a dilution or concentration treatment commonly used in the art. The concentration of the long-chain dicarboxylic acid in the fermentation broth may be adjusted before the start of step (1) or at any stage of step (1). For example, after controlling the pH of the fermentation broth, the concentration of the fermentation broth is adjusted.

[0027] According to some embodiments of the present invention, the method comprises the following steps:

[0028] (1) Controlling the pH of the fermentation liquid to ≤5, controlling the concentration of the long-chain dibasic acid in the fermentation liquid to 5-15 wt%, and the density to 0.9-1.16 g / cm 3 , keeping the fermentation liquid at 92° C. to 103° C. for 10 to 120 minutes, and cooling the mixture to obtain a first solid-liquid mixture, wherein the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 to 1000 μm;

[0029] (2) centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture;

[0030] (3) Separating a long-chain dibasic acid from the second solid-liquid mixture.

[0031] According to some embodiments of the present invention, the temperature of the fermentation liquid in step (1) is 30-90° C., for example, 35° C., 40° C., 45° C., 48° C., 50° C., 55° C., 57° C., 60° C., 62° C., 65° C., 68° C., 70° C., 75° C., 80° C., 85° C., 88° C. The fermentation liquid may be heated to a temperature of 30-90° C.

[0032] According to some embodiments of the present invention, the method comprises the following steps:

[0033] (1) Controlling the temperature of the fermentation liquid to be 30-90°C, the pH of the fermentation liquid to be ≤5, the concentration of the long-chain dibasic acid in the fermentation liquid to be 5-15wt%, and the density to be 0.9-1.16g / cm 3 , keeping the fermentation liquid at 92° C. to 103° C. for 10 to 120 minutes, and cooling the mixture to obtain a first solid-liquid mixture, wherein the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 to 1000 μm;

[0034] (2) centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture;

[0035] (3) Separating a long-chain dibasic acid from the second solid-liquid mixture.

[0036] For the method described in any one of the present invention, the pH of the fermentation broth in step (1) is 2 to 4.77, further 2 to 4.55, further 2 to 4.5, further 2 to 4.1, further 2 to 4.0, further 2 to 3.9, further 2 to 3.8, further 2 to 3.7, further 2 to 3.45.

[0037] For any of the methods of the present invention, in step (1), the pH value of the fermentation broth is controlled by acidifying the fermentation broth, and the acid used for acidification includes: one or a combination of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid and trifluoromethanesulfonic acid.

[0038] For the method described in any one of the present invention, the starting temperature Tm of the cooling treatment in step (1) is 92°C to 103°C, such as 94°C, 96°C, 98°C, 100°C, 101°C, 102°C. The end temperature Tn of the cooling treatment in step (1) is 35°C to 85°C, further 45°C to 80°C, such as 50°C, 60°C, 70°C, 75°C. The cooling rate of the cooling treatment in step (1) is 0.5 to 20°C / h, such as 3°C / h, 5°C / h, 10°C / h, 11°C / h, 13°C / h, 14°C / h, 15°C / h, 18°C / h, 19°C / h.

[0039] For any of the methods described in the present invention, the cooling treatment in step (1) includes primary cooling and secondary cooling. The primary cooling rate is 0.5 to 12°C / h, for example, 3°C / h, 5°C / h, 10°C / h. The starting temperature of the primary cooling is Tm. The end temperature of the primary cooling is T1, for example, 88°C, 89°C, 90°C. The starting temperature of the secondary cooling is T1. The secondary cooling rate is 5 to 20°C / h, for example, 11°C / h, 13°C / h, 14°C / h, 15°C / h, 18°C / h, 19°C / h. The end temperature of the secondary cooling is Tn.

[0040] Through a suitable cooling process, the particle size of the long-chain dibasic acid crystals can be affected, thereby affecting the separation effect of the long-chain dibasic acid from the bacteria and other impurities.

[0041] For the method described in any one of the present invention, in the first solid-liquid mixture of step (1), the D90 of the long-chain dibasic acid particles is 50 to 1000 μm, further 70 to 800 μm, for example 100 μm, 120 μm, 150 μm, 180 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm. The D50 of the long-chain dibasic acid particles is 30 to 500 μm, further 35 to 400 μm, for example 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 80 μm, 100 μm, 150 μm, 250 μm. The D10 of the long-chain dibasic acid particles is 5 to 25 μm, further 5 to 20 μm, for example 6 μm, 8 μm, 15 μm, 17 μm.

[0042] The term D90: 90% cumulative volume particle size is a measure of the particle size distribution such that 90 vol.% of the crystals have a size below this value. The term D50: 50% cumulative volume particle size is a measure of the particle size distribution such that 50 vol.% of the crystals have a size below this value. The term D10: 10% cumulative volume particle size is a measure of the particle size distribution such that 10 vol.% of the crystals have a size below this value.

[0043] For any of the methods described in the present invention, the method for separating the long-chain dibasic acid from the second solid-liquid mixture in step (3) is filtration, further comprising filtration using a plate and frame filter or a chamber filter press.

[0044] The method according to any one of the above items comprises the step of drying the separated long-chain dibasic acid.

[0045] The method according to any one of the above items comprises washing the separated long-chain dibasic acid with 0.5 to 5 times the weight of water, for example, with 1, 3 or 4 times the weight of water, and then performing or not performing a drying step.

[0046] The method according to any one of the above items includes the step of adding water to the second solid-liquid mixture for dilution before separating the long-chain dibasic acid. For example, water is first added to the second solid-liquid mixture to adjust the concentration of the slurry and then the long-chain dibasic acid is separated by filtration.

[0047] After centrifugation, most of the long-chain dibasic acid particles in the fermentation broth enter the second solid-liquid mixture, i.e., the heavy phase, and most of the bacteria enter the third solid-liquid mixture, i.e., the light phase, thereby removing the bacteria. Centrifugation affects the separation effect of long-chain dibasic acids, bacteria, and other impurities. Excessive centrifugal force causes the bacteria to enter the dibasic acid phase, affecting the separation effect. Before centrifugation, factors such as particle size, density, or concentration in the fermentation broth can be balanced, thereby further improving the centrifugal separation effect.

[0048] The temperature of the fermentation broth or the concentration of the long-chain dibasic acid in the fermentation broth can be controlled before centrifugal separation, thereby further improving the yield of the product.

[0049] According to any of the above methods, the long-chain dibasic acid comprises a saturated or unsaturated straight-chain dibasic acid having 9 to 18 carbon atoms; and the long-chain dibasic acid has carboxyl groups at both ends.

[0050] Further, the long-chain dibasic acid includes any one or a combination of deca-dicarboxylic acid, 11-dicarboxylic acid, 12-dicarboxylic acid, 13-dicarboxylic acid, 14-dicarboxylic acid, 15-dicarboxylic acid, 16-dicarboxylic acid, 17-dicarboxylic acid, and 18-dicarboxylic acid. The long-chain dibasic acid has carboxyl groups at both ends.

[0051] Furthermore, the yield of the long-chain dibasic acid product in the method is above 95%, such as above 96%, above 97%, above 98%, above 99%. The purity of the long-chain dibasic acid product obtained in the method is at least above 95%, such as above 97%, above 99%.

[0052] The present invention also claims a long-chain dibasic acid prepared by any of the above methods.

[0053] Compared with the prior art, the technical effects of the present invention are at least:

[0054] 1. This method is simple to operate, requires less equipment and investment, and has high processing efficiency.

[0055] 2. The fermentation broth is centrifuged under acidic conditions to remove most of the bacteria and impurities.

[0056] 3. The method has a high yield and the obtained product has high purity. DETAILED DESCRIPTION

[0057] The invention provides a method for effectively separating long-chain dibasic acid from fermentation broth.

[0058] As used herein, the following terms, unless otherwise indicated, have the following meanings.

[0059] In some embodiments, the long-chain dibasic acid includes, but is not limited to, azelaic acid, sebacic acid, undecane dibasic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecane dibasic acid, hexadecanedioic acid, heptadecanedioic acid, octadecane dibasic acid and isomers and derivatives thereof. The long-chain dibasic acid has carboxyl groups at both ends.

[0060] The term "fermentation broth" means: a liquid system including one or more long-chain dibasic acids. It is obtained by using alkanes, fatty acids and their derivatives as substrates and using a microbial fermentation method. The microorganism can oxidize the terminal methyl groups of alkanes, fatty acids and fatty acid derivatives to carboxyl groups to generate long-chain dibasic acids. The microorganism includes, for example, wild-type bacteria or recombinant bacteria, such as Candida.

[0061] In some embodiments, the fermentation broth includes one long chain dibasic acid; in other embodiments, the fermentation broth includes at least two long chain dibasic acids.

[0062] In some cases, the bacterial cells in the fermentation broth are not removed by separate filtration or centrifugation.

[0063] In some cases, the centrifugation can be continuous centrifugation. In some embodiments, the centrifugation uses a centrifuge, including but not limited to a hydrocyclone, a horizontal decanter centrifuge (referred to as a horizontal screw centrifuge), a siphon scraper centrifuge, or any combination thereof.

[0064] After centrifugation, most of the long-chain dibasic acids enter the second solid-liquid mixture (i.e., the heavy phase after centrifugation), and most of the bacteria enter the third solid-liquid mixture (i.e., the light phase after centrifugation) to be separated from the long-chain dibasic acids.

[0065] The long-chain dibasic acid in the second solid-liquid mixture is solid or granular, and can be separated or recycled by any conventional solid-liquid separation method in the art, such as separation by filtration.

[0066] In some embodiments, the long chain dibasic acid can be separated by plate and frame filtration. In some embodiments, the separated long chain dibasic acid is dried.

[0067] The method for controlling the concentration of the fermentation broth described in the examples includes dilution or concentration treatment commonly used in the art.

[0068] The method for controlling the density of the fermentation broth described in the embodiment includes dilution treatment, concentration treatment, or adding an inorganic salt or an inorganic salt solution to the fermentation broth. For example, when the density of the fermentation broth to be adjusted is low (Example 6), an inorganic salt or an inorganic salt solution can be added to increase the density of the fermentation broth. The inorganic salt can be, for example, sodium sulfate.

[0069] The low carbon dibasic acid described in Table 1 is a dibasic acid with a carbon number less than the main dibasic acid in the product. For example, the low carbon dibasic acid in the dodecanedioic acid product refers to a dibasic acid with a carbon number less than or equal to eleven. The low carbon dibasic acid mainly comes from byproducts produced during the fermentation process.

[0070] The following embodiments are for further explanation, but not for limiting the content of the invention.

[0071] The test method in the embodiment is as follows:

[0072] 1. Gas chromatography detection of dibasic acid: Use standard dibasic acid samples as control, refer to GB5413.27-2010 Determination of fatty acids in infant food and dairy products.

[0073] 2. Bacteria recovery rate: Bacteria recovery rate (%) = bacteria content in the third solid-liquid mixture (g) / bacteria content in the fermentation liquid (g) × 100%.

[0074] 3. Long-chain dibasic acid recovery rate: long-chain dibasic acid recovery rate (%) = long-chain dibasic acid product weight (g) / long-chain dibasic acid content in fermentation broth (g) × 100%.

[0075] The fermentation broth of dodecanedioic acid (DC12 fermentation broth) in Examples 1 to 7 and Comparative Examples 1 and 2 contains 16 wt % of dodecanedioic acid and 1 wt % of bacterial cells. Provided by Cathay (Jinxiang) Biomaterials Co., Ltd.

[0076] Example 1

[0077] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 10 wt%, and the density of the fermentation broth was controlled to be 1.05 g / cm 3 .

[0078] The fermentation liquid was kept at 102°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0079] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0080] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0081] Example 2

[0082] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 10 wt%, and the density of the fermentation broth was controlled to be 1.05 g / cm 3 .

[0083] The fermentation broth was kept at 102°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0084] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2500 rpm.

[0085] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0086] Example 3

[0087] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 10 wt%, and the density of the fermentation broth was controlled to be 1.05 g / cm 3 .

[0088] The fermentation broth was kept at 102°C for 10 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0089] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0090] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0091] Example 4

[0092] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to 8 wt%, and the density of the fermentation broth was controlled to 1.00 g / cm 3 .

[0093] The fermentation broth was kept at 102°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0094] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0095] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0096] Example 5

[0097] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 6 wt%, and the density of the fermentation broth was controlled to be 0.95 g / cm 3 .

[0098] The fermentation broth was kept at 102°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 85°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0099] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0100] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0101] Example 6

[0102] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to 3 wt%, and the density of the fermentation broth was controlled to 1.15 g / cm 3 .

[0103] The fermentation broth was kept at 102°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0104] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0105] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0106] Example 7

[0107] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 4.7, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 10 wt%, and the density of the fermentation broth was controlled to be 1.05 g / cm 3 .

[0108] The fermentation liquid was kept at 85° C. for 60 min, and then cooled to 60° C. at a rate of 16° C. / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0109] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0110] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0111] Comparative Example 1

[0112] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 16 wt%, and the density of the fermentation broth was controlled to be 1.05 g / cm 3 .

[0113] The fermentation broth was kept at 102°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 25°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0114] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0115] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0116] Comparative Example 2

[0117] The fermentation broth of dodecanedioic acid was heated to 62°C, 3.5 mol / L sulfuric acid solution was added to the fermentation broth to adjust the pH of the fermentation broth to 1.5, and then the concentration of dodecanedioic acid in the fermentation broth was controlled to be 10 wt%, and the density of the fermentation broth was controlled to be 1.06 g / cm 3 .

[0118] The fermentation broth was kept at 102°C for 10 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0119] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal screw centrifuge is 500 rpm.

[0120] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain the dodecanedioic acid product.

[0121] Comparative Example 3

[0122] The fermentation liquid of △9-1,18-octadecene dicarboxylic acid contains 10wt% of dodecanedioic acid and 1wt% of bacteria. The fermentation liquid is heated to 62°C, 3.5mol / L sulfuric acid solution is added to the fermentation liquid to adjust the pH of the fermentation liquid to 3.5, and then the concentration of △9-1,18-octadecene dicarboxylic acid in the fermentation liquid is controlled to 8wt%, and the density of the fermentation liquid is controlled to 1.05g / cm 3 .

[0123] The fermentation liquid was kept at 100°C for 60 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of Δ9-1,18-octadecene dicarboxylic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0124] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0125] The obtained second solid-liquid mixture is filtered and separated by a plate and frame filter to obtain △9-1,18-octadecene dibasic acid, and then the △9-1,18-octadecene dibasic acid is washed with 2 times the mass of water, and then dried to obtain the △9-1,18-octadecene dibasic acid product.

[0126] Comparative Example 4

[0127] It is basically the same as Comparative Example 3, except that in Comparative Example 4, the drum speed of the horizontal screw centrifuge is 3200 rpm.

[0128] Example 8

[0129] The fermentation broth of 11-dicarboxylic acid (DC11 fermentation broth, Cathay (Jinxiang) Biomaterial Co., Ltd.) contains 15 wt% of 11-dicarboxylic acid and 1 wt% of bacterial cells. The fermentation broth is heated to 62°C, 3.5 mol / L sulfuric acid solution is added to the fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of 11-dicarboxylic acid in the fermentation broth is controlled to be 10 wt%, and the density of the fermentation broth is controlled to be 1.02 g / cm 3 .

[0130] The fermentation liquid was kept at 92°C for 60 minutes, then cooled to 88°C at a rate of 8°C / h, and then cooled to 45°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of the undecanedicarboxylic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0131] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0132] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain undecanedicarboxylic acid, and then the undecanedicarboxylic acid is washed with 2 times the mass of water and dried to obtain an undecanedicarboxylic acid product.

[0133] Example 9

[0134] The fermentation broth of deca-dicarboxylic acid (DC10 fermentation broth, Cathay (Jinxiang) Biomaterial Co., Ltd.) contains 12 wt% of deca-dicarboxylic acid and 1.2 wt% of bacterial cells. The fermentation broth is heated to 62°C, 3.5 mol / L sulfuric acid solution is added to the fermentation broth to adjust the pH of the fermentation broth to 3.8, and then the concentration of deca-dicarboxylic acid in the fermentation broth is controlled to 8 wt%, and the density of the fermentation broth is controlled to 0.92 g / cm 3 .

[0135] The fermentation broth was kept at 100°C for 50 minutes, then cooled to 89°C at a rate of 8°C / h, and then cooled to 50°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of the decacarbonyl dicarboxylic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0136] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2300 rpm.

[0137] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain decanedicarboxylic acid, and then the decanedicarboxylic acid is washed with 2 times the mass of water and dried to obtain the decanedicarboxylic acid product.

[0138] Example 10

[0139] The fermentation broth of 16-carbon dicarboxylic acid (DC16 fermentation broth, Cathay (Jinxiang) Biomaterial Co., Ltd.) contains 9 wt% of 16-carbon dicarboxylic acid and 0.8 wt% of bacterial cells. The fermentation broth is heated to 62°C, 3.5 mol / L sulfuric acid solution is added to the fermentation broth to adjust the pH of the fermentation broth to 4, and then the concentration of 16-carbon dicarboxylic acid in the fermentation broth is controlled to 6 wt%, and the density of the fermentation broth is controlled to 1.05 g / cm 3 .

[0140] The fermentation broth was kept at 101°C for 80 minutes, then cooled to 90°C at a rate of 8°C / h, and then cooled to 80°C at a rate of 16°C / h to obtain a first solid-liquid mixture. The particle size distribution of hexadecanedioic acid particles in the first solid-liquid mixture was tested, and the test results are shown in Table 1.

[0141] The first solid-liquid mixture is centrifuged in a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2100 rpm.

[0142] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter to obtain hexadecanedioic acid, and then the hexadecanedioic acid is washed with 2 times the mass of water and dried to obtain a hexadecanedioic acid product.

[0143] Table 1 Test results of various indicators

[0144]

[0145]

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for extracting a long-chain dibasic acid from a fermentation broth, the method comprising the following steps: (1) Control the pH of the fermentation liquid to 2-5 and the density to 0.9-1.1 g / cm 3 , after cooling treatment, a first solid-liquid mixture is obtained, and the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 180-1000 μm; (2) centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture having a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture having a long-chain dibasic acid content less than that of the second solid-liquid mixture; (3) separating a long-chain dibasic acid from the second solid-liquid mixture; Wherein, the concentration of the long-chain dibasic acid in the fermentation broth is controlled to be 6-10wt%; The starting temperature Tm of the cooling treatment in step (1) is 92°C~103°C, and the end temperature Tn is 45°C~85°C; before the cooling treatment in step (1), the fermentation liquid is kept at 92°C~103°C for 20~120min; the cooling treatment includes primary cooling and secondary cooling, and the speed of the primary cooling is 0.5~12°C / h; the starting temperature T1 of the secondary cooling is 85~91°C, and the speed of the secondary cooling is 5~20°C / h; the speed of the centrifuge is 1500~2900 rpm.

2. The method according to claim 1, characterized in that: The recovery rate of the bacteria in the third solid-liquid mixture is 90-95%; and / or, the content of the long-chain dibasic acid in the second solid-liquid mixture is ≥40wt%; And / or, the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 180~800μm; and / or, the D50 of the long-chain dibasic acid particles in the first solid-liquid mixture is 30~500μm; and / or, the D10 of the long-chain dibasic acid particles in the first solid-liquid mixture is 5~25μm.

3. The method according to claim 1, characterized in that: The content of the long-chain dibasic acid in the second solid-liquid mixture is 40-70wt%; and / or, the D50 of the long-chain dibasic acid particles in the first solid-liquid mixture is 35-400 μm; And / or, the D10 of the long-chain dibasic acid particles in the first solid-liquid mixture is 5-20 μm.

4. The method according to claim 1, characterized in that: The centrifugal equipment includes a hydrocyclone, a horizontal decanter centrifuge, a siphon scraper centrifuge, or any combination thereof.

5. The method according to claim 4, characterized in that: The centrifugal device is a horizontal sedimentation centrifuge, and the drum speed is 1500~2900 rpm.

6. The method according to claim 1, characterized in that: The terminal temperature Tn of the cooling treatment in step (1) is 60-70°C.

7. The method according to claim 6, characterized in that: The starting temperature of the first stage cooling is Tm; and / or, the end temperature T1 of the first stage cooling is 85-91° C.; and / or, the end temperature of the second stage cooling is Tn.

8. The method according to claim 1, characterized in that: The terminal temperature Tn of the cooling treatment in step (1) is 45-80°C; And / or, controlling the density of the fermentation liquid to be 0.98-1.06 g / cm 3 .

9. The method according to claim 1, characterized in that: The temperature of the fermentation liquid in step (1) is 30-90° C.; and / or, the pH of the fermentation liquid in step (1) is 2-4.77; and / or, the pH value of the fermentation liquid is controlled by acidifying the fermentation liquid in step (1), and the acid used for acidification comprises: one or a combination of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid and trifluoromethanesulfonic acid.

10. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-4.

55.

11. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-4.

5.

12. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-4.

1.

13. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-4.

0.

14. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-3.

9.

15. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-3.

8.

16. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-3.

7.

17. The method according to claim 1, characterized in that: The pH of the fermentation broth in step (1) is 2-3.

45.

18. The method according to claim 1, characterized in that: The method for separating the long-chain dibasic acid from the second solid-liquid mixture in step (3) is filtering; And / or, comprising the step of washing the separated long-chain dibasic acid with 0.5 to 5 times the weight of water, and then performing or not performing drying; and / or, comprising the step of adding water to the second solid-liquid mixture for dilution before separating the long-chain dibasic acid; And / or, comprising the step of drying the separated long-chain dibasic acid.

19. The method according to claim 18, characterized in that: The filtration in step (3) is performed using a plate and frame filter or a chamber filter press.

20. The method according to claim 1, characterized in that: The long-chain dibasic acid includes a saturated or unsaturated straight-chain dibasic acid having 9 to 18 carbon atoms; and both ends of the long-chain dibasic acid have carboxyl groups.

21. The method according to claim 1, characterized in that: The long-chain dibasic acid includes any one or a combination of decacarbon dibasic acid, elevencarbon dibasic acid, twelvecarbon dibasic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedibasic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedibasic acid.

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