Application of MOF-808 and / or HKUST-1 in separation of 5-hydroxymethylfurfural and impure-phase substances

Abstract

The invention belongs to the technical field of adsorption separation, and particularly relates to application of MOF-808 and / or HKUST-1 in separation of 5-hydroxymethylfurfural and impure-phase substances. According to the application, MOF-808 and / or HKUST-1 are / is used as an adsorbent, 5-hydroxymethylfurfural can be well separated from fructose, formic acid, levulinic acid and other impurities, especially HMF and LA can be separated, the selection factor reaches up to 43.8, the defect that efficient separation of the two substances is difficult to achieve in the prior art is overcome, the purity of the separated HMF is high, energy consumption is low during HMF separation, the flow rate is large, and the method is suitable for industrial production. The separation time is short.

Description

Technical Field

[0001] The present invention belongs to the technical field of adsorption separation, and particularly relates to the application of MOF-808 and / or HKUST-1 in separating 5-hydroxymethylfurfural and heterogeneous substances. Background Art

[0002] 5-Hydroxymethylfurfural (HMF) can be used to prepare biofuels, bio-based coatings, cosmetics, pharmaceuticals, degradable plastics, etc. Currently, HMF is mainly obtained by acid-catalyzed dehydration of fructose (Fru). However, by-products such as formic acid (FA) and levulinic acid (LA) are generated during the reaction. Therefore, the product after the reaction needs to be further purified to obtain pure HMF. In the production of HMF, the purification cost accounts for 60-70% of the total cost. Therefore, developing an efficient HMF separation and purification technology is a prerequisite for its wide application. Currently, the main methods for HMF separation and purification include extraction, distillation, membrane separation, and adsorption separation. Among them, adsorption separation can separate low-concentration HMF at low temperature, and has the characteristics of low energy consumption, simple operation, avoiding polymerization of HMF at high temperature, and being recyclable. It is considered to be one of the most competitive separation methods.

[0003] The key to improving the adsorption separation performance lies in the development of adsorbents. Common adsorbents include zeolites, polymers, carbon materials, etc. By improving the hydrophobicity of the material, the proportion of micropores, and constructing a π-electron structure, hydrophobic interaction, extrusion effect, and π-π interaction are used to increase the adsorption capacity and selectivity for HMF. However, there is still a problem that it is difficult to separate HMF from impurities such as LA, FA, and Fru, especially it is difficult to separate HMF from LA. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the inability of the prior art to efficiently separate 5-hydroxymethylfurfural from impurities such as LA, FA, and Fru, and thus provide the application of MOF-808 and / or HKUST-1 in separating 5-hydroxymethylfurfural and heterogeneous substances.

[0005] For this reason, the present invention provides the following technical solutions.

[0006] The first aspect of the present invention provides the application of MOF-808 and / or HKUST-1 in separating 5-hydroxymethylfurfural and heterogeneous substances, and the heterogeneous substances include at least one of fructose, formic acid, and levulinic acid.

[0007] As an optional implementation manner, the MOF-808 is used for separating at least one of fructose, formic acid, and levulinic acid from 5-hydroxymethylfurfural; and / or,

[0008] the HKUST-1 is used for separating fructose and 5-hydroxymethylfurfural.

[0009] In the second aspect of the present invention, a method for separating 5-hydroxymethylfurfural and heterophase substances is provided, including: putting MOF-808 and / or HKUST-1 into a mixed solution for adsorption separation;

[0010] The mixed solution includes 5-hydroxymethylfurfural and heterophase substances; the heterophase substances include at least one of fructose, formic acid, and levulinic acid.

[0011] As an optional implementation manner, the method includes: putting MOF-808 into the mixed solution for adsorption separation; the mixed solution includes 5-hydroxymethylfurfural; the mixed solution further includes at least one of fructose, formic acid, and levulinic acid; and / or,

[0012] putting HKUST-1 into the mixed solution for adsorption separation; the mixed solution includes 5-hydroxymethylfurfural and fructose; and / or,

[0013] The separation is carried out under the condition that the temperature is not higher than 60 °C.

[0014] In the third aspect of the present invention, a chromatographic column for separating 5-hydroxymethylfurfural and heterophase substances is provided. The chromatographic column includes a packing material, and the packing material includes MOF-808 and / or HKUST-1. The heterophase substances include at least one of fructose, formic acid, and levulinic acid.

[0015] As an optional implementation manner, the chromatographic column includes a first chromatographic column, and the packing material of the first chromatographic column includes MOF-808; and / or, the chromatographic column includes a second chromatographic column, and the packing material of the second chromatographic column includes HKUST-1;

[0016] Preferably, the packing density of MOF-808 in the first chromatographic column is 100 g / L - 800 g / L; by way of example, the packing density is any value among 100 g / L, 200 g / L, 300 g / L, 400 g / L, 500 g / L, 600 g / L, 700 g / L, 800 g / L;

[0017] Preferably, the packing density of HKUST-1 in the second chromatographic column is 100 g / L - 800 g / L; by way of example, the packing density is any value among 100 g / L, 200 g / L, 300 g / L, 400 g / L, 500 g / L, 600 g / L, 700 g / L, 800 g / L;

[0018] Preferably, the length-to-diameter ratio of the first chromatographic column is 10 - 50; by way of example, the length-to-diameter ratio is any value among 10, 20, 30, 40, 50;

[0019] Preferably, the aspect ratio of the second chromatographic column is 10 - 50; exemplarily, the aspect ratio is any value among 10, 20, 30, 40, and 50.

[0020] The fourth aspect of the present invention provides a method for separating 5 - hydroxymethylfurfural and heterogeneous substances, using the above - mentioned chromatographic column.

[0021] As an alternative embodiment, the method includes: the mixed solution flows through the chromatographic column to separate 5 - hydroxymethylfurfural; the mixed solution includes 5 - hydroxymethylfurfural and heterogeneous substances;

[0022] Preferably, the mixed solution flows through the first chromatographic column for adsorption separation; the mixed solution includes 5 - hydroxymethylfurfural; the mixed solution further includes at least one of fructose, formic acid, and levulinic acid;

[0023] Preferably, the mixed solution flows through the second chromatographic column for adsorption separation; the mixed solution includes 5 - hydroxymethylfurfural and fructose.

[0024] As an alternative embodiment, the method includes the following steps:

[0025] The mixed solution flows through the first chromatographic column for primary adsorption separation, and the mixed solution includes 5 - hydroxymethylfurfural, fructose, formic acid, and levulinic acid;

[0026] The effluent of the primary adsorption separation flows through the second chromatographic column for secondary adsorption separation.

[0027] As an alternative embodiment, the separation is carried out under the condition that the temperature is not higher than 60 °C; and / or,

[0028] When carrying out the separation, the flow rate of the mixed solution is 0.1 - 50 BV / h, exemplarily, the flow rate is any value among 0.1 BV / h, 1 BV / h, 5 BV / h, 8 BV / h, 10 BV / h, 20 BV / h, 30 BV / h, 40 BV / h, and 50 BV / h; and / or,

[0029] After the secondary adsorption separation, it further includes an elution step. Preferably, methanol is used as the eluent.

[0030] Based on energy conservation and reducing side reactions generated by HMF during the separation process, the temperature during separation is preferably not higher than 60 °C. For example, any value not higher than 60 °C such as 10 °C, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C, etc. It should be noted that the separation can still be carried out when the temperature is higher than 60 °C.

[0031] When the adsorption separation reaches stability, it is considered that the separation process is completed, and the present invention does not make specific limitations on the separation time.

[0032] The present invention does not specifically limit the concentrations of 5-hydroxymethylfurfural, fructose, formic acid, and levulinic acid in the mixed solution. Generally, they do not exceed the saturation concentrations of 5-hydroxymethylfurfural, fructose, formic acid, and levulinic acid in the mixed solution. The technical solution of the present invention has the following advantages:

[0033] 1. The application of MOF-808 and / or HKUST-1 provided by the present invention in separating 5-hydroxymethylfurfural and heterogeneous substances. Using MOF-808 and / or HKUST-1 as adsorbents, it can preferably separate 5-hydroxymethylfurfural from impurities such as fructose, formic acid, and levulinic acid. In particular, it can separate HMF and LA, with a selectivity factor as high as 43.8, overcoming the defect that it is difficult to achieve efficient separation of these two substances in the prior art. The purity of the separated HMF is high, and when separating HMF, the energy consumption is low, the flow rate is large, and the separation time is short. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is the adsorption amount and selectivity factor of MOF-808 for 5-hydroxymethylfurfural and fructose in Example 1 of the present invention;

[0036] Figure 2 It is the adsorption amount and selectivity factor of MOF-808 for 5-hydroxymethylfurfural and formic acid in Example 2 of the present invention;

[0037] Figure 3 It is the adsorption amount and selectivity factor of MOF-808 for 5-hydroxymethylfurfural and levulinic acid in Example 3 of the present invention;

[0038] Figure 4 It is the adsorption amount and selectivity factor of HKUST-1 for 5-hydroxymethylfurfural and fructose in Example 4 of the present invention;

[0039] Figure 5 It is the adsorption amount and selectivity factor of HKUST-1 for 5-hydroxymethylfurfural and formic acid in Example 5 of the present invention;

[0040] Figure 6 It is the adsorption amount and selectivity factor of HKUST-1 for 5-hydroxymethylfurfural and levulinic acid in Example 6 of the present invention;

[0041] Figure 7is the adsorption capacity of each component in the mixed solution by MOF-808 in Example 7 of the present invention;

[0042] Figure 8 is the adsorption capacity of each component in the mixed solution by HKUST-1 in Example 8 of the present invention;

[0043] Figure 9 is the breakthrough curve obtained in Example 9 of the present invention;

[0044] Figure 10 is the adsorption capacity obtained after different cycle numbers in Example 9 of the present invention;

[0045] Figure 11 is the PXRD pattern of MOF-808 before and after 5 cycles in Example 9 of the present invention;

[0046] Figure 12 is the breakthrough curve obtained in Example 10 of the present invention;

[0047] Figure 13 is the adsorption capacity obtained after different cycle numbers in Example 10 of the present invention;

[0048] Figure 14 is the PXRD pattern of MOF-808 before and after 5 cycles in Example 10 of the present invention;

[0049] Figure 15 is the desorption amount of HMF during the elution process in Example 10 of the present invention;

[0050] Figure 16 is the adsorption capacity of each component in the mixed solution by MIL-100-Al in Comparative Example 1 of the present invention. Detailed implementation manners

[0051] The following examples are provided to better understand the present invention further. They are not limited to the best implementation manners, and do not constitute any limitation to the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with those of other prior arts falls within the protection scope of the present invention.

[0052] For those not specifying specific experimental steps or conditions in the examples, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments not indicating the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0053] Briefly describe the data processing method of the technical solution. The selectivity factor and adsorption capacity recorded in the following examples and comparative examples are obtained by testing according to the well-known methods in this field.

[0054] Exemplarily, the calculation formula of the selectivity factor is:

[0055]

[0056] Among them, α is the selectivity factor of the adsorbent for substance a;

[0057] Q ea is the adsorption capacity of the adsorbent for substance a, with the unit of mg / g;

[0058] C eb is the equilibrium concentration of substance b actually measured after adsorption separation, with the unit of mg / g;

[0059] Q eb is the adsorption capacity of the adsorbent for substance b, with the unit of mg / g;

[0060] C ea is the equilibrium concentration of substance a actually measured after adsorption separation, with the unit of mg / g.

[0061] Each example and comparative example calculates the adsorption capacity of the adsorbent for each component according to the following formula:

[0062]

[0063] Among them, Q e is the adsorption capacity, with the unit of mg / g; C 0 is the initial concentration of each component in the mixed solution, with the unit of mg / g, is the finally corrected equilibrium concentration of each component, with the unit of mg / g; M is the amount of the mixed solution added, with the unit of g; m is the mass of the adsorbent, with the unit of g.

[0064] After the adsorption separation is completed, when calculating the adsorption capacity Q e , it is necessary to correct the equilibrium concentration of each component in the mixed solution to obtain the corrected equilibrium concentration Taking the quaternary mixed system of the mixed solution including fructose, formic acid, levulinic acid, and 5-hydroxymethylfurfural as an example to illustrate the correction principle. Among them, C 0 is the initial concentration of each component in the mixed solution before adding the adsorbent for adsorption separation, and C e is the equilibrium concentration of each component in the mixed solution actually measured after adding the adsorbent for adsorption separation, specifically as follows:

[0065] After the adsorption separation is completed, sort according to the magnitude of the concentration change value △C (△C = C 0 - C e ). First, take the component with the largest concentration change value as the benchmark for the first correction to obtain the first corrected equilibrium concentration of each other component Then, take the initial concentration C 0Sort by the magnitude of the difference from the first corrected equilibrium concentration of each component, excluding the component that was used as the correction benchmark for the first time. Use the component with the largest difference as the benchmark for the second correction to obtain the second corrected equilibrium concentrations of the other components. Sort by the magnitude of the difference from the first corrected equilibrium concentration of each component, excluding the component that was used as the correction benchmark for the first time. Use the component with the largest difference as the benchmark for the second correction to obtain the second corrected equilibrium concentrations of the other components. Sort by the magnitude of the difference between the initial concentration C of each component before adsorption separation 0 and the second corrected equilibrium concentration Excluding the components that were used as the correction benchmarks in the first two times, use the component with the larger difference as the benchmark for the third correction to obtain the third corrected equilibrium concentrations of the other components. Use the last component as the correction benchmark, and use the difference between its initial concentration C before adsorption separation 0 and the third corrected equilibrium concentration to perform the fourth correction to obtain the fourth corrected equilibrium concentrations of the other components. Calculate the equilibrium concentration C of each component in the mixed solution after the adsorption separation ends e and the difference from the fourth corrected equilibrium concentration If the difference of all components is lower than 10 -6 at this time is the corrected equilibrium concentration, and use the following formula to calculate the adsorption capacity of each component. If there is a component with a difference not lower than 10 -6 , then the above steps are recorded as the first-round correction process, and repeat the above steps n times to obtain the equilibrium concentration corrected in the nth round Repeat until the difference between the equilibrium concentration corrected in the (n - 1)th round of all components and the equilibrium concentration corrected in the nth round is lower than 10 -6 . The equilibrium concentration corrected in the nth round is recorded as the corrected equilibrium concentration, and calculate the adsorption capacity of each component according to the following formula.

[0066]

[0067] It should be noted that: ① In the four correction processes of each round, different components are used as the benchmarks for correction respectively; that is, when considering the component with the largest difference, each component can only be used as the correction benchmark once in each round. ② In the correction process of each round, if the C corrected in a certain time increase is negative, then use the one corrected in the previous time of this round as the corrected equilibrium concentration, and calculate Q according to the above formula e . ③ The equilibrium concentration of the benchmark component in the last correction of each round is the same as the equilibrium concentration in the penultimate correction.

[0068] ​Exemplarily, taking the mixed system of fructose, formic acid, levulinic acid, 5-hydroxymethylfurfural and water as an example to illustrate the correction process of the equilibrium concentration, the initial concentrations of fructose, formic acid, levulinic acid, 5-hydroxymethylfurfural and water in the mixed system are C 0Fru , C 0FA , C 0LA , C 0HMF , C 0H2O ; after adsorption separation, the equilibrium concentrations of each component in the mixed system are respectively: C eFru , C eFA , C eLA , C eHMF , C eH2O ; the concentration change values of each component before and after adsorption are ΔC Fru , ΔC FA , ΔC LA , ΔC HMF ; including the following steps:

[0069] (1) First, sort from large to small according to the magnitude of the concentration change value;

[0070] (2) Taking the component with the largest concentration change value as the reference for the first correction, calculate the concentration increase values of the other three components. Taking the concentration change value of HMF as the maximum value as an example, it is:

[0071]

[0072]

[0073]

[0074] Among them, represents the increase value of each component concentration caused by the adsorption of the correction reference component.

[0075] Calculate the equilibrium concentrations of the first correction of the other three components in the first round according to the following formula

[0076]

[0077]

[0078] (3) Calculate the concentration change value 0 of the initial concentration C of each component and the equilibrium concentration after the first correction . The calculation formula is as follows;

[0079]

[0080]

[0081]

[0082] (4) Since the previous correction was based on HMF, this step does not consider HMF and only considers LA, Fru, and FA. Sort ΔC 1 in descending order, and perform the second correction based on the component with the largest concentration change value. Calculate the increased values of the concentrations of the other three components. At this time, taking the largest as an example, it is:

[0083]

[0084]

[0085]

[0086] (5) Calculate the equilibrium concentrations of the other three components in the second correction of the first round The calculation formula is as follows:

[0087]

[0088]

[0089]

[0090] (6) When making corrections in this step, HMF and FA are no longer considered, and the concentration change values of the two components Fru and LA are The calculation formula is as follows:

[0091]

[0092]

[0093] (7) Sort the above two ΔC 2 and perform the third correction based on the component with the larger concentration change value. Calculate the increased values of the other three components. Taking Fru being larger as an example:

[0094]

[0095]

[0096]

[0097] (8) Calculate the equilibrium concentrations of the other three components in the third correction of the first round for each component The calculation formula is as follows:

[0098]

[0099]

[0100]

[0101] (9) At this time, the change value of the concentration of the LA component is Calculated as follows:

[0102]

[0103] (10) At this time, the fourth correction is carried out based on the change value of LA, and the increase values of the other three components are calculated. The calculation is as follows:

[0104]

[0105]

[0106]

[0107] (11) Calculate the equilibrium concentrations of the other three components after the fourth correction in the first round for each component The calculation formula is as follows:

[0108]

[0109]

[0110]

[0111] At this time, the It should be specially noted that the equilibrium concentration of the reference component during the fourth correction in each round is the same as the equilibrium concentration during the third correction.

[0112] (12) The change values of the concentrations of the four components are Calculated as follows:

[0113]

[0114]

[0115]

[0116]

[0117] When the above differences are all lower than 10 -6 At this time, the adsorption capacities of each component are output using the following formula.

[0118]

[0119] (13) If at least one of the above differences is ≥10 -6For the difference value, repeat the above steps (1)-(12) for n rounds, calculate the difference between the equilibrium concentration of the nth round and the equilibrium concentration of the (n - 1)th round. When the difference of all components is lower than 10 -6 , use the following formula to output the adsorption capacity of each component:

[0120]

[0121] where Q e is the adsorption capacity, with the unit of mg / g; C 0 is the initial concentration of each component in the mixed solution before adsorption separation, with the unit of mg / g, is the finally corrected equilibrium concentration of each component, with the unit of mg / g; M is the addition amount of the mixed solution, with the unit of g; m is the mass of the adsorbent, with the unit of g.

[0122] To understand the technical solution more clearly, some specific implementation manners are listed here, but not limited to the following embodiments.

[0123] As an implementation manner, a method for separating 5-hydroxymethylfurfural and heterophase substances includes the following steps: putting MOF-808 and / or HKUST-1 into the mixed solution for adsorption separation; the mixed solution includes 5-hydroxymethylfurfural and heterophase substances; the heterophase substances include at least one of fructose, formic acid, and levulinic acid.

[0124] As a specific implementation manner, a method for separating 5-hydroxymethylfurfural and heterophase substances includes the following steps: putting MOF-808 into the mixed solution for adsorption separation; the mixed solution includes 5-hydroxymethylfurfural; the mixed solution also includes at least one of fructose, formic acid, and levulinic acid.

[0125] As a specific implementation manner, a method for separating 5-hydroxymethylfurfural and heterophase substances includes the following steps: putting HKUST-1 into the mixed solution for adsorption separation; the mixed solution includes 5-hydroxymethylfurfural and fructose.

[0126] As an alternative implementation manner, a method for separating 5-hydroxymethylfurfural and heterophase substances includes the following steps: the mixed solution flows through a chromatographic column to separate 5-hydroxymethylfurfural; the mixed solution includes 5-hydroxymethylfurfural and heterophase substances; the chromatographic column includes a packing material selected from MOF-808 and / or HKUST-1; the heterophase substances include at least one of fructose, formic acid, and levulinic acid.

[0127] As a specific embodiment, the method for separating 5-hydroxymethylfurfural and heterogeneous substances comprises the following steps: the mixed solution flows through a first chromatographic column for adsorption separation; the mixed solution comprises 5-hydroxymethylfurfural; the mixed solution further comprises at least one of fructose, formic acid and levulinic acid; the packing of the first chromatographic column comprises MOF-808.

[0128] As a specific embodiment, the method for separating 5-hydroxymethylfurfural and heterogeneous substances comprises the following steps: the mixed solution flows through a second chromatographic column for adsorption separation; the mixed solution comprises 5-hydroxymethylfurfural and fructose; the packing of the second chromatographic column comprises HKUST-1. Optionally, it further comprises the step of eluting with methanol as an eluent.

[0129] As a specific embodiment, the method for separating 5-hydroxymethylfurfural and heterogeneous substances comprises the following steps: ① the mixed solution flows through a first chromatographic column for primary adsorption separation, the mixed solution comprises 5-hydroxymethylfurfural, fructose, formic acid and levulinic acid; ② the effluent of the primary adsorption separation flows through a second chromatographic column for secondary adsorption separation; ③ methanol is used as an eluent for elution.

[0130] Example 1

[0131] This example provides a method for separating 5-hydroxymethylfurfural and fructose, comprising:

[0132] 2 ml of the mixed solution was added to 10 mg of MOF-808, and the mass of the added mixed solution was recorded. It was placed at 30 °C and shaken at 140 rpm for 2 h for adsorption separation. The mixed solution comprised fructose at a concentration of 5 mg / g and 5-hydroxymethylfurfural at a concentration of 20 mg / g. MOF-808 adsorbed fructose to separate fructose and 5-hydroxymethylfurfural.

[0133] Example 2

[0134] This example provides a method for separating 5-hydroxymethylfurfural and formic acid, comprising:

[0135] 2 ml of the mixed solution was added to 10 mg of MOF-808, and the mass of the added mixed solution was recorded. It was placed at 30 °C and shaken at 140 rpm for 2 h for adsorption separation. The mixed solution comprised formic acid at a concentration of 5 mg / g and 5-hydroxymethylfurfural at a concentration of 20 mg / g. MOF-808 adsorbed formic acid to separate formic acid and 5-hydroxymethylfurfural.

[0136] Example 3

[0137] This example provides a method for separating 5-hydroxymethylfurfural and levulinic acid, comprising:

[0138] Add 2 ml of the mixed solution to 10 mg of MOF-808, record the mass of the added mixed solution, place it at 30 °C, and perform adsorption separation under a shaker at 140 rpm for 2 h. The mixed solution includes levulinic acid at a concentration of 5 mg / g and 5-hydroxymethylfurfural at a concentration of 20 mg / g. MOF-808 adsorbs levulinic acid to separate levulinic acid and 5-hydroxymethylfurfural.

[0139] Figures 1-3 They are the adsorption amounts and selectivity factors of MOF-808 for 5-hydroxymethylfurfural, fructose, formic acid, and levulinic acid in Examples 1-3 respectively. Figures 1-3 Judging from this, MOF-808 has relatively high selectivity factors for fructose, formic acid, and levulinic acid, which are 43.8, 53.5, and 43.8 respectively.

[0140] Example 4

[0141] This example provides a method for separating 5-hydroxymethylfurfural and fructose, including:

[0142] Add 2 ml of the mixed solution to 10 mg of HKUST-1, record the mass of the added mixed solution, place it at 30 °C, and perform adsorption separation under a shaker at 140 rpm for 2 h. The mixed solution includes fructose at a concentration of 5 mg / g and 5-hydroxymethylfurfural at a concentration of 20 mg / g. HKUST-1 adsorbs 5-hydroxymethylfurfural to separate fructose and 5-hydroxymethylfurfural.

[0143] Example 5

[0144] This example provides a method for separating 5-hydroxymethylfurfural and formic acid, including:

[0145] Add 2 ml of the mixed solution to 10 mg of HKUST-1, record the mass of the added mixed solution, place it at 30 °C, and perform adsorption separation under a shaker at 140 rpm for 2 h. The mixed solution includes formic acid at a concentration of 5 mg / g and 5-hydroxymethylfurfural at a concentration of 20 mg / g. HKUST-1 adsorbs 5-hydroxymethylfurfural to separate formic acid and 5-hydroxymethylfurfural.

[0146] Example 6

[0147] This example provides a method for separating 5-hydroxymethylfurfural and levulinic acid, including:

[0148] Add 2 ml of the mixed solution to 10 mg of HKUST-1, record the mass of the added mixed solution, place it at 30 °C, and perform adsorption separation under a shaker at 140 rpm for 2 h. The mixed solution includes levulinic acid at a concentration of 5 mg / g and 5-hydroxymethylfurfural at a concentration of 20 mg / g. HKUST-1 adsorbs 5-hydroxymethylfurfural to separate levulinic acid and 5-hydroxymethylfurfural.

[0149] Figures 4-6 are the adsorption amounts and selectivity factors of HKUST-1 for 5-hydroxymethylfurfural, fructose, formic acid, and levulinic acid in Examples 4-6, respectively. Judging from Figures 4-6 it, HKUST-1 can separate 5-hydroxymethylfurfural from fructose, formic acid, and levulinic acid, and the selectivity factors are infinity, 10.3, and 4.3, respectively. HKUST-1 has the best separation effect on the binary mixture system of 5-hydroxymethylfurfural and fructose in particular.

[0150] Example 7

[0151] This example provides a method for separating 5-hydroxymethylfurfural and heterogeneous substances, including:

[0152] Adding 10 mg of MOF-808 to 2 ml of the mixed solution, recording the mass of the added mixed solution, and placing it on a shaker at 30 °C and 140 rpm for 2 h for adsorption separation. The mixed solution includes fructose at a concentration of 5 mg / g, formic acid at a concentration of 5 mg / g, levulinic acid at a concentration of 5 mg / g, and 5-hydroxymethylfurfural at a concentration of 20 mg / g. The adsorption capacities of MOF-808 for each component are shown in Figure 7 .

[0153] Example 8

[0154] This example provides a method for separating 5-hydroxymethylfurfural and heterogeneous substances. The difference from Example 7 is that HKUST-1 is used instead of MOF-808, and the adsorption results are shown in Figure 8 .

[0155] Judging from Figures 7-8 it, the present invention uses MOF-808 and HKUST-1 as adsorbents, and can separate HMF from Fru, FA, and LA. MOF-808 has the best separation effect on the separation of HMF from levulinic acid, formic acid, etc., and HKUST-1 has the best separation effect on the separation of HMF and fructose.

[0156] Examples 1-8 illustrate that both MOF-808 and HKUST-1 can be applied to the separation of HMF.

[0157] Example 9

[0158] This example provides a chromatographic column for separating 5-hydroxymethylfurfural and heterogeneous substances, including a first chromatographic column. The packing of the first chromatographic column includes MOF-808. The length of this chromatographic column is 100 mm, the diameter is 4.6 mm, and the packing density is 353 g / L.

[0159] The preparation method of the first chromatographic column includes: dispersing 586 mg of MOF-808 in water and packing it into the first chromatographic column.

[0160] This embodiment also provides a method for separating 5-hydroxymethylfurfural and heterogeneous substances. Using the above chromatographic column, the method includes the following steps:

[0161] The mixed solution includes fructose at a concentration of 5 mg / g, formic acid at a concentration of 5 mg / g, levulinic acid at a concentration of 5 mg / g, and 5-hydroxymethylfurfural at a concentration of 20 mg / g. The first chromatographic column is activated with 0.5 M HCl at a flow rate of 0.3 BV / min for 30 min, and then washed with ultrapure water at a flow rate of 0.3 BV / min for 10 h. The above mixed solution is injected into the first chromatographic column at a flow rate of 0.3 BV / min for separation, and the effluent is collected. The concentration of each component in the effluent is measured by HPLC every 2 min to obtain the breakthrough curve and the adsorption capacity of the chromatographic column for each component. The results are shown in Figure 9 and Figure 10 , MOF-808 adsorbs FA and LA, and the effluent in the first 18 min includes HMF and Fru, realizing the separation of HMF, Fru from FA and LA.

[0162] After the above experiment, the first chromatographic column is regenerated and reused. Specifically, it includes: first, washing the column with 0.5 M HCl at a flow rate of 0.3 BV / min for 1 h, then washing the column with methanol at a flow rate of 0.3 BV / min for 20 min, then washing the column with pure water at a flow rate of 0.3 BV / min for 2 h, then washing the column with 0.5 M HCl at a flow rate of 0.3 BV / min for 1 h, then washing the column with methanol at a flow rate of 0.3 BV / min for 20 min, and finally washing the column with pure water at a flow rate of 0.3 BV / min for 10 h. Then, the chromatographic column is applied to the second experiment. In this way, the cycle performance of the chromatographic column is tested repeatedly for 5 times. The adsorption amount of MOF-808 for each component in each cycle process is shown in Figure 10 . Figure 11 is the PXRD pattern of MOF-808 before and after 5 cycles in this embodiment. From Figures 10-11 it can be seen that MOF-808 has good stability, with almost no difference before and after use, and can be recycled.

[0163] Example 10

[0164] This embodiment provides a chromatographic column for separating 5-hydroxymethylfurfural, including a second chromatographic column. The packing of the second chromatographic column includes HKUST-1. The length of this chromatographic column is 100 mm, the diameter is 4.6 mm, and the packing density is 382 g / L.

[0165] The preparation method of the second chromatographic column includes: dispersing 634 mg of HKUST-1 in methanol and packing it into the second chromatographic column.

[0166] This embodiment also provides a method for separating 5-hydroxymethylfurfural. Using the above chromatographic column, the method includes the following steps:

[0167] The mixed solution includes fructose with a concentration of 5 mg / g and 5-hydroxymethylfurfural with a concentration of 20 mg / g. The mixed solution is injected into the second chromatographic column for separation at a flow rate of 0.3 BV / min, and the effluent is collected. The concentration of each component in the effluent of this step is measured by HPLC every 1 min to obtain the breakthrough curve and the adsorption capacity of the chromatographic column for each component. The results are shown in Figure 12 and Figure 13 , achieving the separation of fructose and 5-hydroxymethylfurfural.

[0168] After the above experiment, the second chromatographic column is regenerated and reused, which specifically includes: washing the column with methanol at a flow rate of 0.3 BV / min for 60 min, and then applying the chromatographic column to the second experiment. In this way, the cyclic performance of the chromatographic column is tested repeatedly for 5 cycles. The adsorption amounts of HKUST-1 for fructose and 5-hydroxymethylfurfural in each cycle are shown in Figure 13 (It should be specially noted that in the second cycle, the concentration of fructose is twice that of other cycles, aiming to illustrate whether the fructose concentration will affect the adsorption of HMF by HKUST-1). Figure 14 is the PXRD pattern of HKUST-1 before and after 5 cycles in Example 10. From Figures 13-14 it can be seen that HKUST-1 has good stability, with almost no difference before and after use, and can be recycled repeatedly.

[0169] Furthermore, this embodiment also includes an elution step, which specifically includes: using methanol as an eluent to elute the second chromatographic column, so that HMF is desorbed from the chromatographic column and dissolved in the methanol solvent to obtain a concentrated solution containing methanol and HMF, and separating methanol and HMF to obtain HMF products. The desorption amount of HMF during the elution process is shown in Figure 15 . It can be seen from the figure that when using methanol as an eluent to desorb HMF from the chromatographic column in the present invention, the time is short, the efficiency is high, the amount of methanol used is small, the content of HMF in the concentrated solution containing methanol and HMF obtained is high, and since the boiling point of methanol is low, the energy consumption can be significantly reduced when separating HMF products in the later stage.

[0170] Comparative Example 1

[0171] This comparative example provides a method for separating 5-hydroxymethylfurfural, which is different from Example 7 in that MIL-100-Al is used instead of MOF-808. The adsorption results are shown in Figure 16 .

[0172] Obviously, the above embodiments are merely examples given for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. Application of MOF-808 and / or HKUST-1 in separation of 5-hydroxymethylfurfural and heterogeneous substances, characterized in that: The heterogeneous material includes at least one of fructose, formic acid and levulinic acid.

2. The use according to claim 1, characterized in that: The MOF-808 is used for separation of at least one of fructose, formic acid and levulinic acid from 5-hydroxymethylfurfural; and / or, The HKUST-1 is used for separation of fructose and 5-hydroxymethylfurfural.

3. A method for separating 5-hydroxymethylfurfural and heterogeneous substances, characterized in that: The method comprises: placing MOF-808 and / or HKUST-1 into a mixed liquid for adsorption separation; The mixed solution includes 5-hydroxymethylfurfural and heterogeneous substances; the heterogeneous substances include at least one of fructose, formic acid and levulinic acid.

4. The method according to claim 3, characterized in that The method comprises: placing MOF-808 into a mixed solution for adsorption separation; the mixed solution comprises 5-hydroxymethylfurfural; the mixed solution further comprises at least one of fructose, formic acid and levulinic acid; and / or, placing HKUST-1 into a mixed solution for adsorption separation; the mixed solution comprises 5-hydroxymethylfurfural and fructose; and / or, The separation is carried out at a temperature not higher than 60°C.

5. A chromatographic column for separating 5-hydroxymethylfurfural and heterogeneous substances, characterized in that: The chromatographic column comprises a filler, wherein the filler comprises MOF-808 and / or HKUST-1, and the heterophase substance comprises at least one of fructose, formic acid and levulinic acid.

6. The chromatographic column according to claim 5, characterized in that The chromatographic column comprises a first chromatographic column, the filler of the first chromatographic column comprises MOF-808; and / or, the chromatographic column comprises a second chromatographic column, the filler of the second chromatographic column comprises HKUST-1; Preferably, the packing density of MOF-808 in the first chromatographic column is 100 g / L-800 g / L; Preferably, the packing density of HKUST-1 in the second chromatographic column is 100 g / L-800 g / L; Preferably, the aspect ratio of the first chromatographic column is 10-50; Preferably, the aspect ratio of the second chromatographic column is 10-50.

7. A method for separating 5-hydroxymethylfurfural and heterogeneous substances, characterized in that: The chromatographic column according to claim 5 or 6 is used.

8. The method according to claim 7, characterized in that include: The mixed solution flows through the chromatographic column to separate 5-hydroxymethylfurfural; the mixed solution includes 5-hydroxymethylfurfural and heterogeneous substances; Preferably, the mixed solution flows through the first chromatographic column for adsorption separation; the mixed solution includes 5-hydroxymethylfurfural; the mixed solution also includes at least one of fructose, formic acid and levulinic acid; Preferably, the mixed solution flows through a second chromatographic column for adsorption separation; the mixed solution comprises 5-hydroxymethylfurfural and fructose.

9. The method according to claim 8, characterized in that The following steps are involved: The mixed solution flows through a first chromatographic column for primary adsorption separation, wherein the mixed solution includes 5-hydroxymethylfurfural, fructose, formic acid and levulinic acid; The effluent from the primary adsorption separation flows through the second chromatographic column for secondary adsorption separation.

10. The method according to any one of claims 7 to 9, characterized in that: The separation is carried out at a temperature not higher than 60°C; and / or, When performing the separation, the flow rate of the mixed solution is 0.1-50 BV / h; and / or, The secondary adsorption separation further includes an elution step, and preferably, methanol is used as the eluent.

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