A method for co-producing isosorbide and mannitol and the obtained products and applications

Abstract

The invention discloses a method for co-producing isosorbide and mannitol, and the obtained products and applications, and belongs to the technical field of functional sugar preparation. The invention liquefies and saccharifies starch to prepare glucose; obtains sorbitol component, mannitol component and glucose component through hydrogenation treatment, refining and chromatographic separation; prepares mannitol after refining and crystallization of the mannitol component; dehydrates and catalyzes the sorbitol component with concentrated sulfuric acid and palladium mixture as catalyst to prepare a crude liquid containing isosorbide, and prepares an isosorbide product through separation, purification and crystallization; glucose can be returned to saccharification and then further hydrogenated. The invention uses starch as raw material, and while preparing sorbitol, glucose and mannitol are separated, glucose is reused, and mannitol is refined and crystallized to obtain a mannitol product, thereby improving the utilization rate of raw materials; using concentrated sulfuric acid and palladium mixture as catalyst, the generation of by-products is reduced, and the conversion rate of isosorbide is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of functional sugar preparation, and in particular relates to a method for co-producing isosorbide and mannitol, and the obtained products and applications. Background Art

[0002] Isosorbide, Chinese name 1,4:3,6-dianhydro-D-sorbitol, English name Isosorbide, is the secondary dehydration product of sorbitol, with a molecular formula of C6H 10 O4, molecular weight is 146.1412, melting point is 56-62℃, boiling point is 372.1℃ under atmospheric pressure, and flash point is 178.8℃. As a new type of bio-based material, it can be widely used in food, cosmetics, medicine, plastics and polymers. For example, in medicine, isosorbide is an effective osmotic oral dehydration diuretic, which has been used in clinical practice abroad. In industry, isosorbide is an important intermediate for the preparation of Span and Tween surfactants. Due to its special chirality, it can be used as an intermediate in the synthesis of liquid crystal materials and is widely used in electronics, national defense and other fields. In particular, isosorbide is used as a comonomer in the modification of polymers such as polyether, polyester, polyurethane, and polycarbonate, which can significantly improve the high temperature performance and impact resistance of polymers and has extremely high added value. However, the traditional process for preparing isosorbide generally uses concentrated sulfuric acid or solid acid as a catalyst. During the reaction, sorbitol is severely carbonized, the reaction solution is very dark in color, the subsequent extraction is difficult, and the production cost is generally high. At the same time, the traditional process for preparing isosorbide also has the defects of low isosorbide conversion rate and low product purity, which to a certain extent limits the scope of application of isosorbide in industry.

[0003] Mannitol, also known as mannitol, has a chemical formula of C6H 14 O6 is a white crystalline solid. It belongs to the hexadecene class of substances and is a commonly used dehydrating agent with a diuretic effect. It can also be used as a sweetener. The traditional industrial production process of mannitol usually involves isomerization of glucose to obtain fructose, and fructose is catalytically hydrogenated to produce mannitol. In actual industrial production, the catalytic hydrogenation process has high requirements for the purity of fructose, but due to the low efficiency of isomerization, losses during fructose separation, and the presence of impurities, it is challenging to obtain a high-purity fructose product, which in turn affects the yield and purity of mannitol. In addition, the preparation, use, and replacement costs of enzymes during isomerization are high. At the same time, in order to ensure the reaction conditions and product yield, a large amount of energy and chemical reagents are also required, resulting in high production costs.

[0004] Therefore, it is particularly important to provide a method for co-producing isosorbide and mannitol, which can simplify the production process, obtain isosorbide and mannitol at the same time, improve the conversion rate and purity of isosorbide and mannitol, reduce the generation of by-products, and reduce production costs. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a method for co-producing isosorbide and mannitol, which can reduce the generation of by-products, improve the conversion rate, obtain isosorbide and mannitol with higher purity, and the obtained glucose component can be recycled, thereby improving the utilization rate of raw materials and reducing production costs.

[0006] Another object of the present invention is to provide isosorbide prepared by the method for co-producing isosorbide and mannitol.

[0007] Another object of the present invention is to provide mannitol prepared by the method for co-producing isosorbide and mannitol.

[0008] Another object of the present invention is to provide a use of the isosorbide and / or mannitol in the preparation of food, medicine, cosmetics, plastic products or polymers.

[0009] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0010] The present invention provides a method for co-producing isosorbide and mannitol, the method comprising the following steps:

[0011] Starch is liquefied and saccharified to prepare a glucose-containing liquid; the glucose-containing liquid is hydrogenated, refined, and chromatographically separated to obtain a sorbitol component, a mannitol component, and a glucose component respectively; the glucose component is mixed with the glucose-containing liquid for reuse; the mannitol component is refined and crystallized to obtain mannitol; the sorbitol component is dehydrated and catalyzed to obtain a crude liquid containing isosorbide; the crude liquid is separated, purified, and crystallized to obtain isosorbide;

[0012] The dehydration catalysis uses a mixture of concentrated sulfuric acid and palladium as a catalyst and hydrogen as a reducing agent.

[0013] Preferably, the conditions for the hydrogenation treatment are: adjusting the pH of the glucose-containing liquid to 8-9, the solid content to 40%-50%, the pressure to 5-10 MPa, and the temperature to 120-160°C.

[0014] Preferably, the chromatographic separation method comprises: a circulation step, a water-in-and-glucose-out step, and a double-in-and-double-out step;

[0015] The circulation step includes: the feed liquid runs in the resin system, circulates internally, and realizes the separation of different components; the water-inlet and glucose-outlet step includes: after circulation, the feed liquid is separated, and then water is introduced for elution, and glucose is preferentially discharged from the system; the double-inlet and double-outlet step includes: the feed liquid in the circulation step further discharges glucose, and double water is introduced to respectively discharge sorbitol and mannitol.

[0016] Preferably, the conditions for the chromatographic separation are: adjusting the solid content of the feed liquid to 55%-65%, the mass ratio of elution water to feed liquid to be 1:(2.5-4), and the temperature to be 55-65°C.

[0017] Preferably, the mass ratio of concentrated sulfuric acid to palladium in the mixture of concentrated sulfuric acid and palladium is 5:1 to 8:1.

[0018] Preferably, the added amount of the catalyst is 5%~10% / T.DS.

[0019] Preferably, the dehydration catalytic reaction conditions are: adjusting the sorbitol component concentration to 35%-55%, the temperature to 100-300° C., and the time to 2-6 hours.

[0020] The invention also provides isosorbide prepared by the method.

[0021] The invention also provides mannitol prepared by the method.

[0022] The present invention also provides an application of the isosorbide and / or the mannitol in the preparation of food, medicine, cosmetics, plastic products or polymers.

[0023] Beneficial effects of the present invention:

[0024] The invention uses starch as a raw material to prepare sorbitol, and separates mannitol and glucose while preparing sorbitol. The glucose can be returned for saccharification and then further subjected to hydrogenation treatment, thereby improving the utilization rate of the raw materials. In the process of glucose hydrogenation, it is not necessary to undergo isomerization treatment, and a mannitol component can be obtained by separation through a chromatographic column. The mannitol product is prepared through refining, crystallization and drying, thereby further improving the utilization rate of the raw materials, improving the output efficiency and saving the production cost.

[0025] When separating sorbitol, mannitol and glucose components, the chromatographic separation method adopted by the present invention realizes the simultaneous separation of the three components of sorbitol, mannitol and glucose. On the one hand, a set of chromatograms is saved and the cost caused by the chromatography is reduced. On the other hand, compared with the current three-phase chromatography, two columns are added to realize the simultaneous separation of three different components, thereby improving the purity of the product and reducing the loss.

[0026] The invention uses hydrogen as a reducing agent when sorbitol is dehydrated to produce isosorbide, thereby reducing the generation of intermediate by-products; a mixture of concentrated sulfuric acid and palladium is used as a catalyst for co-catalysis, thereby increasing the conversion rate of isosorbide to more than 90%, thereby improving the conversion effect of isosorbide; and after separation and purification, an isosorbide product with higher purity is obtained, thereby laying a foundation for industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the technical route of the method of the present invention;

[0028] Figure 2 Schematic diagram of the chromatographic separation principle of Example 1; wherein A represents the refined feed liquid circulating in the resin, B represents the influent water elution to obtain the glucose component, C represents the influent water elution to obtain the sorbitol and mannitol components, and the influent is glucose; Z1~Z4 represent 8 calcium-type chromatographic separation resins in zones 1~4, respectively, the blue solid squares represent sorbitol, the purple solid squares represent mannitol, and the red solid squares represent glucose. DETAILED DESCRIPTION

[0029] The present invention provides a method for co-producing isosorbide and mannitol, the method comprising the following steps:

[0030] Starch is liquefied and saccharified to prepare a glucose-containing liquid; the glucose-containing liquid is hydrogenated, refined, and chromatographically separated to obtain a sorbitol component, a mannitol component, and a glucose component respectively; the glucose component is mixed with the glucose-containing liquid for reuse; the mannitol component is refined and crystallized to obtain mannitol; the sorbitol component is dehydrated and catalyzed to obtain a crude liquid containing isosorbide; the crude liquid is separated, purified, and crystallized to obtain isosorbide;

[0031] The dehydration catalysis uses a mixture of concentrated sulfuric acid and palladium as a catalyst and hydrogen as a reducing agent.

[0032] In the present invention, the starch liquefaction treatment preferably further includes a slurry adjustment step to obtain starch milk. The concentration of the starch milk is preferably 16 to 18 degrees Baume, more preferably 17 degrees Baume. The starch milk is liquefied and saccharified to prepare a glucose-containing liquid. The liquefaction preferably includes adjusting the pH of the starch milk and adding a liquefying enzyme to the starch milk. The pH is preferably 5.5 to 6.5, more preferably 6. The type of the liquefaction enzyme can be conventionally selected according to actual needs, preferably a thermostable α-amylase; the liquefaction enzyme can be purchased through conventional channels; the amount of the liquefaction enzyme added is preferably 200-300 mL / T.DS, more preferably 250 mL / T.DS; wherein "mL / T.DS" represents the amount of enzyme preparation added per ton of dry basis, for example, 250 mL / T.DS represents the addition of 250 mL of liquefaction enzyme per ton of dry basis; the temperature and time of the liquefaction can be conventionally selected according to actual needs. As an optional embodiment, the liquefaction temperature is preferably 100-110°C, more preferably 105°C; the liquefaction time is preferably 15-25 min, more preferably 20 min. After the liquefaction, the glucose value (DE value) of the obtained starch solution is preferably 3%-8%, more preferably 5%. The saccharification preferably includes adjusting the pH of the starch solution and adding a saccharifying enzyme to the starch solution. The pH is preferably 4.5-5.5, more preferably 5. The saccharifying enzyme can be conventionally selected according to actual needs and can be purchased through conventional channels; the amount of the saccharifying enzyme added is preferably 400~600mL / T.DS, more preferably 500mL / T.DS. The temperature of the saccharification can be conventionally selected according to actual needs. As an optional embodiment, the temperature of the saccharification is preferably 55~65°C, more preferably 60°C. The time of the saccharification can be conventionally selected according to actual needs. After the saccharification, the glucose content in the obtained glucose-containing liquid is preferably ≥98%. After the saccharification, the obtained grape-containing liquid is preferably also refined. The method of the refining treatment can be conventionally selected according to actual needs. As an optional embodiment, the refining preferably includes decolorization and desalination; the decolorization is preferably carried out by using a granular activated carbon column for decolorization; the desalination is preferably carried out by using an ionization desalination method to obtain a refined glucose-containing liquid.

[0033] In the present invention, the glucose-containing feed liquid is subjected to hydrogenation treatment, refining, and chromatographic separation to obtain sorbitol component, mannitol component and glucose component respectively. The conditions of the hydrogenation treatment preferably include: adjusting the pH of the glucose-containing feed liquid to preferably 8-9, more preferably 8.5; the solid content of the glucose-containing feed liquid is preferably 40%-50%, more preferably 45%; the pressure of the hydrogenation treatment is preferably 5-10MPa, more preferably 6MPa; the temperature of the hydrogenation treatment is preferably 120-160°C, more preferably 140°C; the time of the hydrogenation treatment is preferably 1-6h, more preferably 2-4h. In the present invention, after the hydrogenation treatment, the refining treatment is carried out. The method of the refining treatment can be conventionally selected according to actual needs. As an optional embodiment, the refining preferably includes decolorization and desalination; the decolorization is preferably carried out by using a granular activated carbon column for decolorization; the desalination is preferably carried out by using an ionization desalination method to obtain a refined feed liquid. In the present invention, after the glucose-containing liquid is hydrogenated and refined, the solid content of the refined liquid is adjusted to preferably 55% to 65%, more preferably 60%.

[0034] In the present invention, the chromatographic separation method preferably includes: a circulation step, a water-inlet and glucose-outlet step and a double-inlet and double-outlet step. The circulation step preferably includes: the feed liquid runs in the resin system, circulates internally, and realizes the separation of different components. The water-inlet and glucose-outlet step preferably includes: after circulation, the feed liquid realizes separation, and then water is introduced for elution, and glucose preferentially exits the system. The double-inlet and double-outlet step preferably includes: the feed liquid in the circulation step further outputs glucose, and double water is introduced to respectively output sorbitol and mannitol. In the double-inlet and double-outlet step of the present invention, water is introduced through two ports, and two different components, namely sorbitol and mannitol, are respectively output, thereby further realizing the separation of different components.

[0035] In the present invention, the chromatographic separation preferably uses a calcium-type chromatographic separation resin, and the model of the calcium-type chromatographic separation resin can be conventionally selected according to actual needs and can be purchased through conventional channels. The number of resin columns for the chromatographic separation is preferably 7 to 9, and more preferably 8; as an implementable embodiment, the chromatographic column is divided into zone 1, zone 2, zone 3 and zone 4 connected in a closed loop in sequence according to the positions of the inlet and outlet, the circulating liquid inlet and outlet, and the overall flow direction of the feed liquid, wherein zone 1 has 3 resin columns arranged in series, zone 2 has 2 resin columns arranged in series, zone 3 has 2 resin columns arranged in series, and zone 4 has 1 resin column arranged. The conditions for the chromatographic separation are preferably: the mass ratio of elution water to feed liquid is preferably 1:(2.5-4), more preferably 1:(2.8-3.5); the temperature is preferably 55-65°C, more preferably 60°C; the time for one cycle of the chromatographic separation is preferably 40-50 min, more preferably 45 min; the one cycle refers to the circulation step, the water inlet and glucose outlet step, and the double-inlet and double-outlet step running for one cycle; the processing capacity is preferably 0.01-0.05 T.DS / cubic meter resin / h, more preferably 0.03 T.DS / cubic meter resin / h; wherein, "T.DS / cubic meter resin / h" means the dry basis mass processed per cubic meter of resin per hour, for example, 0.03 T.DS / cubic meter resin / h means that 0.03 tons of dry basis is processed per cubic meter of resin per hour.

[0036] As a specific optional implementation method, the chromatographic separation method includes: a circulation step: the feed liquid runs in a resin system composed of 8 chromatographic columns connected in series, and the internal circulation is realized to realize the separation of different components; a water-inlet and glucose-outlet step: after the circulation, the feed liquid is separated, the first resin column is inletted with water for elution, and the seventh resin column collects the glucose component; a double-inlet and double-outlet step: the feed liquid in the circulation step further outputs glucose, the seventh resin column collects the glucose component, the first resin column is inletted with water for elution, the first resin column collects the sorbitol component, the second resin column is inletted with water for elution, and the third resin column collects the mannitol component.

[0037] The present invention achieves the simultaneous separation of three components, namely, sorbitol, mannitol and glucose, by adjusting the number of chromatographic columns, chromatographic separation conditions and a double-input and double-output mode in the chromatographic separation method. The chromatographic separation method of the present invention saves one set of chromatograms and reduces the cost of the chromatograms. On the other hand, compared with the current three-phase chromatogram, two columns are added to achieve the separation between different components, improve the purity of the product and reduce the loss.

[0038] In the present invention, the glucose component is mixed with the glucose-containing feed liquid for reuse, and the hydrogenation step is continued, thereby improving the utilization rate of the raw materials.

[0039] In the present invention, the mannitol component is refined and crystallized to prepare mannitol. The refining and crystallization methods can be conventionally selected according to actual needs.

[0040] In the present invention, the sorbitol component is dehydrated and catalyzed to prepare a crude liquid containing isosorbide, and the crude liquid is separated, purified and crystallized to prepare isosorbide. Before the dehydration catalytic reaction, the sorbitol concentration in the sorbitol component is adjusted to preferably 35% to 55%, more preferably 40% to 50%. The dehydration catalysis uses a mixture of concentrated sulfuric acid and palladium as a catalyst and hydrogen as a reducing agent; the mass ratio of concentrated sulfuric acid to palladium in the mixture of concentrated sulfuric acid and palladium is preferably 5:1 to 8:1, more preferably 6:1. The concentrated sulfuric acid and palladium can be purchased through conventional channels. The amount of the catalyst added is preferably 5% to 10% / T.DS, more preferably 5% to 8% / T.DS or 6% to 8% / T.DS; for example, 5% / T.DS means that 50 kg of catalyst is added to 1 ton of dry basis. The temperature of the dehydration catalysis is preferably 100 to 300°C, more preferably 150 to 180°C; the time of the dehydration catalysis is preferably 2 to 6 hours, more preferably 5 to 6 hours. The separation and purification method of the crude liquid can be conventionally selected according to actual needs, such as a conventional two-component chromatographic separation method. As an optional embodiment, it is preferred to use a calcium-type chromatographic separation resin for separation and purification; the model of the calcium-type chromatographic separation resin can be conventionally selected according to actual needs and can be purchased through conventional channels; the separation and purification conditions are preferably: the mass ratio of elution water to feed liquid is preferably 1: (1~3), more preferably 1: (1.68~1.8); the temperature is preferably 55~65°C, more preferably 60°C. The crystallization method can be conventionally selected according to actual needs.

[0041] The present invention uses starch as a raw material to prepare sorbitol. In the process of preparing sorbitol by hydrogenation of glucose, no special isomerization treatment is required. While preparing sorbitol, mannitol and glucose can also be separated. Glucose can be returned for saccharification and then further subjected to hydrogenation treatment to improve the utilization rate of raw materials. The separated mannitol component is refined, crystallized and dried to prepare a mannitol finished product, which further improves the utilization rate of raw materials, improves the output efficiency, and saves production costs. When sorbitol is dehydrated and catalyzed to produce isosorbide, hydrogen is used as a reducing agent to reduce the generation of intermediate by-products, and concentrated sulfuric acid and a palladium mixture are used as catalysts for catalysis, so that the conversion rate of isosorbide can be increased to more than 90%, further improving the conversion effect of isosorbide and the purity of isosorbide.

[0042] The invention also provides isosorbide prepared by the method.

[0043] The invention also provides mannitol prepared by the method.

[0044] The present invention also provides an application of the isosorbide and / or the mannitol in the preparation of food, medicine, cosmetics, plastic products or polymers.

[0045] The isosorbide or mannitol prepared by the present invention has high purity and can be widely used in the fields of food, medicine, cosmetics, plastics, polymers, etc. For example, it can be added to food, medicine or cosmetics as a functional additive, or used as an intermediate in the synthesis of plastic products, or used in the modification of polymers, etc.

[0046] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0047] In the following embodiments, unless otherwise specified, all of them are conventional methods.

[0048] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0049] Example 1

[0050] A method for co-producing isosorbide and mannitol, the method being as follows:

[0051] (1) Preparation of glucose: starch slurry is prepared to obtain starch milk, the concentration of starch milk is adjusted to 17 degrees Baume, the pH is adjusted to 6.0, 250mL / T.DS high temperature resistant α-amylase is added for liquefaction, liquefaction is carried out at 105℃ for 20min, the DE value is controlled to be 5% after liquefaction, and the iodine test is brown or purple red; after liquefaction, the pH is adjusted to 5.0, 500mL / T.DS saccharifying enzyme is added, saccharification treatment is carried out at 60℃, and the glucose content in the prepared glucose-containing liquid is detected after 24h, and the glucose content is ≥98%. Purification treatment of glucose-containing liquid: at 50℃, it is decolorized by passing through a granular activated carbon column at a flow rate of 2BV / h, and then the decolorized and filtered syrup is passed through a positive column-anion column-anion column at a flow rate of 3 times the resin volume / hour at 40℃ in sequence for ion exchange desalting to obtain a refined glucose-containing liquid; wherein, the positive column is a strong acid positive resin D001 FD, and the negative column is a weak base anion resin D301P FD.

[0052] (2) Hydrogenation: The pH of the refined glucose-containing liquid was adjusted to 8.5 and the solid content was 45.0%. The hydrogenation reaction was carried out at a pressure of 6.0 MPa and a temperature of 140°C for 2 h. The component detection results were as follows: sorbitol 85.1%, mannitol 7.5%, and glucose 7.4%. The hydrogenated liquid was refined by passing through a granular activated carbon column for decolorization at a flow rate of 2 BV / h at 50°C. The decolorized and filtered syrup was then passed through a cation column-anion column-anion column in sequence at a flow rate of 3 times the resin volume / h at 40°C for ion exchange and desalting to obtain a refined liquid. The cation column was a strong acid cation resin D001FD and the anion column was a weak base anion resin D301P FD.

[0053] (3) Chromatographic separation: adjust the solid content of the refined liquid in (2) to 60%, select calcium type chromatographic separation resin, the number of resin columns is 8, the mass ratio of elution water to liquid is 1:2.8, the temperature is 60°C, the cycle time is 45 minutes, the processing volume is 0.03 T.DS / m3 resin / h, the chromatographic column arrangement method and the separation method are as follows: Figure 2 As shown, specifically: cycle steps ( Figure 2 Middle A): The feed liquid runs in a resin system consisting of 8 chromatographic columns connected in series, and circulates internally to achieve separation of different components; water inlet and glucose outlet steps ( Figure 2 Middle B): After the cycle, the feed liquid is separated, the first resin column is eluted with water, and the seventh resin column collects the glucose component; double-input and double-output steps ( Figure 2 In the middle C): the feed liquid in the circulation step further produces glucose, the 7th resin column collects the glucose component, the 1st resin column is eluted with water, the 1st resin column collects the sorbitol component, the 2nd resin column is eluted with water, and the 3rd resin column collects the mannitol component. According to the interception of each component in the column, three different components of glucose, mannitol and sorbitol are obtained in turn: the sorbitol content in the sorbitol component is 98.5%; the mannitol content in the mannitol component is 98.5%; the glucose content in the glucose component is 90%; the mannitol component is refined and crystallized to prepare the mannitol product; the glucose component is returned to the saccharification and then hydrogenated for reuse.

[0054] (4) Dehydration catalysis: The sorbitol concentration in the sorbitol component was adjusted to 40%. At a temperature of 150°C, hydrogen was used as a reducing agent and a mixture of concentrated sulfuric acid and palladium was used as a catalyst. The mass ratio of concentrated sulfuric acid to palladium was 6:1. The amount of catalyst added was 8% / T.DS. After dehydration catalysis for 5 hours, a crude liquid containing isosorbide was prepared. After testing, the purity of isosorbide in the crude liquid was 90.2%, sorbitol was 7.1%, and miscellaneous sugars were 2.7%.

[0055] (5) Separation and purification: The crude liquid in (4) was refined, separated and purified, and calcium-type chromatographic separation resin was selected. A conventional two-component chromatographic separation method was used, and the mass ratio of elution water to feed liquid was selected to be 1:1.8, the temperature was 60°C, the cycle time was 55 minutes, and the processing volume was 0.028 T.DS / cubic meter of resin / h. After testing, after separation and purification, the isosorbide content was 98.5%, and the sorbitol content was 1.5%.

[0056] (6) Crystallization product: The liquid in (5) is purified and crystallized to obtain the isosorbide product.

[0057] Example 2

[0058] A method for co-producing isosorbide and mannitol, the method being as follows:

[0059] (1) Preparation of glucose: starch slurry is prepared to obtain starch milk, the concentration of starch milk is adjusted to 17 degrees Baume, the pH is adjusted to 6.0, 250mL / T.DS high temperature resistant α-amylase is added for liquefaction, liquefaction is carried out at 105℃ for 20min, the DE value is controlled to be 5% after liquefaction, and the iodine test is brown or purple red; after liquefaction, the pH is adjusted to 5.0, 500mL / T.DS saccharifying enzyme is added, saccharification treatment is carried out at 60℃, and the glucose content in the prepared glucose-containing liquid is detected after 24h, and the glucose content is ≥98%. Purification treatment of glucose-containing liquid: at 50℃, it is decolorized by passing through a granular activated carbon column at a flow rate of 2BV / h, and then the decolorized and filtered syrup is passed through a positive column-anion column-anion column at a flow rate of 3 times the resin volume / hour at 40℃ in sequence for ion exchange desalting to obtain a refined glucose-containing liquid; wherein, the positive column is a strong acid positive resin D001 FD, and the negative column is a weak base anion resin D301P FD.

[0060] (2) Hydrogenation: The pH of the refined glucose-containing liquid was adjusted to 8.5 and the solid content was 45.0%. The hydrogenation reaction was carried out at a pressure of 6.0 MPa and a temperature of 140°C for 2 h. The component detection results were as follows: sorbitol 85.1%, mannitol 7.5%, and glucose 7.4%. The hydrogenated liquid was refined by passing it through a granular activated carbon column for decolorization at a flow rate of 2 BV / h at 50°C. The decolorized and filtered syrup was then passed through a cation column-anion column-anion column in sequence at a flow rate of 3 times the resin volume / h at 40°C for ion exchange and desalting to obtain a refined liquid. The cation column was a strong acid cation resin D001FD and the anion column was a weak base anion resin D301 PFD.

[0061] (3) Chromatographic separation: The solid content of the refined feed liquid in (2) was adjusted to 60%, and a calcium-type chromatographic separation resin was selected. The number of resin columns was 8, the mass ratio of eluting water to feed liquid was 1:3.5, and the temperature was 60°C; the cycle time was 45 minutes, the processing volume was 0.03 T.DS / m3 resin / h, and the chromatographic column arrangement method and separation method were the same as those in Example 1. According to the retention of each component in the column, three different components, glucose, mannitol, and sorbitol, were obtained in turn: the sorbitol content in the sorbitol component was 99.2%, the mannitol content in the mannitol component was 98.9%, and the glucose content in the glucose component was 92.0%; the mannitol component was refined and crystallized to prepare a mannitol product; the glucose component was returned for saccharification and then catalytically reused.

[0062] (4) Dehydration catalysis: The sorbitol concentration in the sorbitol component was adjusted to 40%. At a temperature of 150°C, hydrogen was used as a reducing agent and a mixture of concentrated sulfuric acid and palladium was used as a catalyst. The mass ratio of concentrated sulfuric acid to palladium was 6:1. The amount of catalyst added was 6% / T.DS. After dehydration catalysis for 5 hours, a crude liquid containing isosorbide was prepared. After testing, the purity of isosorbide in the crude liquid was 92.5%, sorbitol was 5.3%, and miscellaneous sugars were 2.2%.

[0063] (5) Separation and purification: The crude liquid in (4) was refined, separated and purified, and calcium-type chromatographic separation resin was selected. A conventional two-component chromatographic separation method was used, and the mass ratio of elution water to feed liquid was selected to be 1:1.7, the temperature was 60°C, the cycle time was 55 minutes, and the processing volume was 0.028 T.DS / cubic meter of resin / h. After testing, after separation and purification, an isosorbide content of 98.0% and a sorbitol content of 2.0% were prepared.

[0064] (6) Crystallization product: The liquid in (5) is purified and crystallized to obtain the isosorbide product.

[0065] Example 3

[0066] A method for co-producing isosorbide and mannitol comprises the following steps:

[0067] (1) Preparation of glucose: starch slurry is prepared to obtain starch milk, the concentration of starch milk is adjusted to 17 degrees Baume, the pH is adjusted to 6.0, 250mL / T.DS high temperature resistant α-amylase is added for liquefaction, liquefaction is carried out at 105℃ for 20min, the DE value is controlled to be 5% after liquefaction, and the iodine test is brown or purple red; after liquefaction, the pH is adjusted to 5.0, 500mL / T.DS saccharifying enzyme is added, saccharification treatment is carried out at 60℃, and the glucose content in the prepared glucose-containing liquid is detected after 24h, and the glucose content is ≥98%. Purification treatment of glucose-containing liquid: at 50℃, it is decolorized by passing through a granular activated carbon column at a flow rate of 2BV / h, and then the decolorized and filtered syrup is passed through a positive column-anion column-anion column at a flow rate of 3 times the resin volume / hour at 40℃ in sequence for ion exchange desalting to obtain a refined glucose-containing liquid; wherein, the positive column is a strong acid positive resin D001 FD, and the negative column is a weak base anion resin D301P FD.

[0068] (2) Hydrogenation: The pH of the refined glucose-containing liquid was adjusted to 8.5 and the solid content was 45.0%. The hydrogenation reaction was carried out at a pressure of 6.0 MPa and a temperature of 140°C for 2 h. The component detection results were as follows: sorbitol 85.1%, mannitol 7.5%, and glucose 7.4%. The hydrogenated liquid was refined by passing through a granular activated carbon column for decolorization at a flow rate of 2 BV / h at 50°C. The decolorized and filtered syrup was then passed through a cation column-anion column-anion column in sequence at a flow rate of 3 times the resin volume / h at 40°C for ion exchange and desalting to obtain a refined liquid. The cation column was a strong acid cation resin D001FD and the anion column was a weak base anion resin D301P FD.

[0069] (3) Chromatographic separation: The solid content of the refined feed liquid in (2) was adjusted to 60%, and a calcium-type chromatographic separation resin was selected. The number of resin columns was 8, the mass ratio of eluting water to feed liquid was 1:3.5, and the temperature was 60°C; the cycle time was 45 minutes, the processing volume was 0.03 T.DS / m3 resin / h, and the chromatographic column arrangement method and separation method were the same as those in Example 1. According to the retention of each component in the column, three different components, glucose, mannitol, and sorbitol, were obtained in turn: the sorbitol content in the sorbitol component was 99.2%, the mannitol content in the mannitol component was 98.9%, and the glucose content in the glucose component was 92.0%; the mannitol component was refined and crystallized to prepare a mannitol product; the glucose component was returned for saccharification and then catalytically reused.

[0070] (4) Dehydration catalysis: The sorbitol concentration in the sorbitol component was adjusted to 50%. At a temperature of 180°C, hydrogen was used as a reducing agent and a mixture of concentrated sulfuric acid and palladium was used as a catalyst. The mass ratio of concentrated sulfuric acid to palladium was 6:1. The amount of catalyst added was 5% / T.DS. After dehydration catalysis for 6 hours, a crude liquid containing isosorbide was prepared. After testing, the purity of isosorbide in the crude liquid was 94.2%, sorbitol was 2.5%, and miscellaneous sugars were 3.3%.

[0071] (5) Separation and purification: The crude liquid in (4) was refined, separated and purified, and calcium-type chromatographic separation resin was selected. A conventional two-component chromatographic separation method was used, and the mass ratio of elution water to feed liquid was selected to be 1:1.68, the temperature was 60°C, the cycle time was 55 minutes, and the processing volume was 0.028 T.DS / cubic meter of resin / h. After testing, after separation and purification, the isosorbide content was 98.9% and the sorbitol content was 1.1%.

[0072] (6) Crystallization product: The liquid in (5) is purified and crystallized to obtain the isosorbide product.

[0073] Comparative Example 1

[0074] A method for co-producing isosorbide and mannitol, which differs from Example 1 in that:

[0075] (3) Chromatographic separation: The solid content of the refined feed liquid in (2) was adjusted to 60%, and a calcium-type chromatographic separation resin was selected. The number of resin columns was 8, the mass ratio of eluting water to feed liquid was 1:2, and the temperature was 60°C; the cycle time was 45 minutes, the processing volume was 0.03 T.DS / m3 resin / h, and the chromatographic column arrangement method and separation method were the same as those in Example 1. According to the retention of each component in the column, three different components, glucose, mannitol, and sorbitol, were obtained in turn: the sorbitol content in the sorbitol component was 95.2%, the mannitol content in the mannitol component was 93.5%, and the glucose content in the glucose component was 88.2%; the mannitol component was refined and crystallized to prepare a mannitol product; the glucose component was returned for saccharification and then catalytically reused.

[0076] (4) Dehydration catalysis: The sorbitol concentration in the sorbitol component was adjusted to 40%. At a temperature of 150°C, hydrogen was used as a reducing agent and a mixture of concentrated sulfuric acid and palladium was used as a catalyst. The mass ratio of concentrated sulfuric acid to palladium was 6:1. The amount of catalyst added was 8% / T.DS. After dehydration catalysis for 5 hours, a crude liquid containing isosorbide was prepared. After testing, the purity of isosorbide in the crude liquid was 85.0%, sorbitol was 12.7%, and miscellaneous sugars were 2.3%.

[0077] Comparative Example 2

[0078] A method for co-producing isosorbide and mannitol, which differs from Example 1 in that:

[0079] (4) Dehydration catalysis: The sorbitol concentration in the sorbitol component was adjusted to 40%. At a temperature of 150°C, hydrogen was used as a reducing agent, concentrated sulfuric acid was used as a catalyst, and the catalyst addition amount was 8% / T.DS. After dehydration catalysis for 5 hours, a crude liquid containing isosorbide was prepared. After testing, the purity of isosorbide in the crude liquid was 71.2%, sorbitol was 25.4%, and miscellaneous sugars were 3.4%.

[0080] Comparative Example 3

[0081] A method for co-producing isosorbide and mannitol, which differs from Example 1 in that:

[0082] (4) Dehydration catalysis: The sorbitol concentration in the sorbitol component was adjusted to 40%. At a temperature of 150°C, hydrogen was used as a reducing agent, and a mixture of perfluorosulfonic acid resin and palladium was used as a catalyst, wherein the mass ratio of perfluorosulfonic acid resin to palladium was 6:1, and the amount of catalyst added was 8% / T.DS. After dehydration catalysis for 5 hours, a crude liquid containing isosorbide was prepared. After testing, the purity of isosorbide in the crude liquid was 81.5%, sorbitol was 15.0%, and miscellaneous sugars were 3.5%.

[0083] Comparative Example 4

[0084] A method for co-producing isosorbide and mannitol, which differs from Example 1 in that:

[0085] Adjust the chromatographic separation parameters: (3) Chromatographic separation: adjust the solid content of the refined liquid in (2) to 60%, select calcium-type chromatographic separation resin, adopt the conventional two-component chromatographic separation method, the number of resin columns is 6, the mass ratio of elution water to liquid is 1:2, the temperature is 60°C; one cycle time is 45 min, the processing volume is 0.03 T.DS / cubic meter resin / h, and the chromatographic column arrangement method is 1 column in zone 1, 2 columns in zone 2, 2 columns in zone 3, and 1 column in zone 4. The chromatographic separation method is specifically as follows: circulation step: the feed liquid runs in a resin system composed of 6 series-connected chromatographic columns, and the internal circulation is realized to separate different components; water inlet and glucose outlet step: the first resin column is eluted with water, and the fifth resin column collects the glucose component; double-inlet and double-outlet step: the feed liquid in the circulation step further outputs glucose, the fifth resin column collects the glucose component, the first resin column is eluted with water, the first resin column first collects the mannitol component, the first resin column is eluted with water again, and the first resin column collects the sorbitol component. According to the interception of each component in the column, three different components of glucose, mannitol, and sorbitol are obtained in turn: the sorbitol content in the sorbitol component is 90.2%, the mannitol content in the mannitol component is 85.2%, and the glucose content in the glucose component is 85.2%; the mannitol component is refined and crystallized to prepare the mannitol product; the glucose component is returned for saccharification and catalytic reuse.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for co-producing isosorbide and mannitol, characterized in that: The method comprises the following steps: Starch is liquefied and saccharified to prepare a glucose-containing liquid; the glucose-containing liquid is hydrogenated, refined, and chromatographically separated to obtain a sorbitol component, a mannitol component, and a glucose component respectively; the glucose component is mixed with the glucose-containing liquid for reuse; the mannitol component is refined and crystallized to obtain mannitol; the sorbitol component is dehydrated and catalyzed to obtain a crude liquid containing isosorbide; the crude liquid is separated, purified, and crystallized to obtain isosorbide; The dehydration catalysis uses a mixture of concentrated sulfuric acid and palladium as a catalyst and hydrogen as a reducing agent; The chromatographic separation method comprises: a circulation step, a water-input and glucose-output step, and a double-input and double-output step; The circulation step includes: the feed liquid runs in the resin system, circulates internally, and separates different components; The step of introducing water and discharging glucose comprises: after circulation, the feed liquid is separated, and then water is introduced for elution, and glucose is preferentially discharged from the system; The double-input and double-output step comprises: the feed liquid in the circulation step further outputs glucose, and double-input water outputs sorbitol and mannitol respectively; During the chromatographic separation, the mass ratio of elution water to feed liquid is 1:(2.5~4).

2. The method according to claim 1, characterized in that The conditions of the hydrogenation treatment are: adjusting the pH of the glucose-containing liquid to 8-9, the solid content to 40%-50%, the pressure to 5-10 MPa, and the temperature to 120-160°C.

3. The method according to claim 1, characterized in that The conditions for the chromatographic separation are: adjusting the solid content of the feed liquid to 55%-65% and the temperature to 55-65°C.

4. The method according to claim 1, characterized in that: The number of resin columns used in the chromatographic separation is 7 to 9.

5. The method according to claim 4, characterized in that The number of resin columns used in the chromatographic separation is 8.

6. The method according to claim 5, characterized in that The resin columns are divided into zone 1, zone 2, zone 3 and zone 4 which are connected in a closed loop in sequence according to the positions of the inlet and outlet, the circulating liquid inlet and outlet and the overall flow direction of the feed liquid, wherein zone 1 has three resin columns arranged in series, zone 2 has two resin columns arranged in series, zone 3 has two resin columns arranged in series, and zone 4 has one resin column arranged.

7. The method according to claim 5, characterized in that The chromatographic separation method comprises: Circulation step: the feed liquid runs in a resin system consisting of 8 chromatographic columns connected in series, and circulates internally to achieve separation of different components; Water inlet and glucose outlet step: After circulation, the feed liquid is separated, the first resin column is eluted with water, and the seventh resin column collects the glucose component; Double-in and double-out step: the feed liquid in the circulation step further discharges glucose, the 7th resin column collects the glucose component, the 1st resin column is eluted with water, the 1st resin column collects the sorbitol component, the 2nd resin column is eluted with water, and the 3rd resin column collects the mannitol component.

8. The method according to claim 1, characterized in that The mass ratio of concentrated sulfuric acid to palladium in the mixture of concentrated sulfuric acid and palladium is 5:1 to 8:

1.

9. The method according to claim 1, characterized in that: The added amount of the catalyst is 5%~10% / T.DS.

10. The method according to claim 1, characterized in that The dehydration catalytic reaction conditions are: adjusting the concentration of the sorbitol component to 35%-55%, the temperature to 100-300° C., and the time to 2-6 hours.

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