A high-selectivity roll-type membrane and its application

Abstract

The present invention belongs to the technical field of sugar separation, and relates to a high-selectivity roll membrane and its application. The separation membrane of the membrane bag contained in the membrane sheet group of the high-selectivity roll membrane is formed by a polyamide separation membrane, and the polyamide separation membrane includes a porous support layer and a modified polyamide separation layer loaded on the surface of the porous support layer; the modified polyamide separation layer is formed by interfacial polymerization of a composite polyamine and a polyacyl chloride in the presence of a humic acid salt, and the composite polyamine is a complex of an aliphatic polyamine and adamantane-modified diamine in a mass ratio of 1:(0.1-0.5), and the adamantane-modified diamine is a product of an addition reaction of adamantane diamine and an alicyclic diisocyanate in a molar ratio of (1.2-2):1; the general formula of the adamantane diamine is NH2(CH2) n R 1 (CH2) m NH2. The roll membrane provided by the present invention can stably operate at a high flux under high pressure conditions and can be stably used for the separation of monosaccharides and polysaccharides for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of sugar separation, and in particular relates to a high-selectivity rolled membrane and application thereof. Background Art

[0002] Sugar, also known as carbohydrates (carbohydrate or saccharide), is an organic compound composed of three elements: carbon, hydrogen and oxygen. It is a general term for polyhydroxy aldehydes, polyhydroxy ketones and compounds that can be hydrolyzed to form polyhydroxy aldehydes or polyhydroxy ketones. Sugar is an important and functional active substance on which human beings depend for survival. It is of great significance and importance in the food, medicine, fermentation and other industries. Sugar is widely distributed in nature and is an important structural substance and energy source for organisms. According to the number of monosaccharides generated after the hydrolysis of sugars, it can be divided into monosaccharides and polysaccharides.

[0003] Monosaccharides refer to molecules that cannot be simply hydrolyzed into smaller sugars. They are the simplest form of sugars. Common monosaccharides include glucose, fructose, galactose, etc. Glucose is the main energy source for life activities and the main component of blood sugar. It is widely found in plants and animal tissues. Fructose is mainly found in fruits and honey, and its sweetness is higher than glucose. Galactose is mainly found in dairy products and is a component of lactose. Monosaccharides can be directly absorbed and utilized by the human body to provide energy for the body. Polysaccharides are compounds formed by two or more monosaccharides connected by glycosidic bonds, including disaccharides and oligosaccharides. Common disaccharides include sucrose, lactose, maltose, etc. Common oligosaccharides include starch, cellulose and glycogen, etc.

[0004] Existing methods for separating monosaccharides and polysaccharides include membrane separation, solubility difference method, gel filtration, graded precipitation, electrophoresis, etc. Among them, the membrane separation method uses a selectively permeable membrane as a separation medium, applies a driving force on both sides of the membrane, and allows the components in the raw liquid to selectively pass through the membrane to achieve purification and concentration. For the separation of monosaccharides and polysaccharides, the commonly used membrane is usually a roll membrane, which includes components such as a membrane bag, a feed grid, a dialysate grid, and a dialysate collection tube. Among them, the roll membrane used for separating monosaccharides and polysaccharides is generally a polyamide membrane. Although polyamide membranes can be used to separate monosaccharides and polysaccharides, the flux is low and the separation time is long. Summary of the invention

[0005] The first purpose of the present invention is to overcome the defect of low flux when using existing roll membranes to separate monosaccharides and polysaccharides, and to provide a high-flux and high-selectivity roll membrane that can be used stably for the separation of monosaccharides and polysaccharides for a long time.

[0006] After in-depth and extensive research, the inventors of the present invention found that one of the main reasons why the flux is low when using existing roll membranes to separate monosaccharides and polysaccharides is that the existing roll membranes can generally only operate under low pressure environments (operating pressure is 15-30MPa), and the membrane material is prone to softening when operating under high pressure environments. In response to this, the inventors of the present invention improved the membrane material of the roll membrane, introduced a small amount of adamantane modified diamine obtained by addition reaction of adamantane diamine and alicyclic diisocyanate in the preparation process of the polyamide separation layer, and compounded the adamantane modified diamine with aliphatic polyamines as polyamines, and ensured that the process of forming the polyamide separation layer by interfacial polymerization was carried out in the presence of humates, which can significantly improve the flux and operation stability. The reason is speculated to be that: on the one hand, the adamantane modified diamine obtained by the addition reaction of adamantane diamine and alicyclic diisocyanate has a rigid twisted structure, which can inhibit the close stacking between polymer segments. The free volume of the membrane can be enhanced by its combination with aliphatic polyamines, making the membrane loose to be very conducive to the permeation of monosaccharides and the retention of polysaccharides; on the other hand, the cations in humate can combine with carbon groups, enhance the interaction between segments, and transform the polyamide from a linear molecule into a supramolecular system with a network structure, thereby improving the mechanical properties of the polyamide, enabling it to operate stably under high pressure, and the operating pressure can be increased to 60-100 MPa; on the other hand, humate is hydrophilic, and the introduction of humate can improve the hydrophilicity of the membrane, which is conducive to the passage of monosaccharides, thereby improving the flux of the membrane. Based on this, the present invention is completed.

[0007] The membrane element body of the high-selectivity spiral membrane provided by the present invention comprises a central tube and a membrane sheet group wound on the central tube, wherein the separation membrane of the membrane bag contained in the membrane sheet group is formed by a polyamide separation membrane, and the polyamide separation membrane comprises a porous support layer and a modified polyamide separation layer supported on the surface of the porous support layer; the modified polyamide separation layer is formed by interfacial polymerization of a composite polyamine and a polyacyl chloride in the presence of a humic acid salt, the composite polyamine is a composite of an aliphatic polyamine and adamantane modified diamine in a mass ratio of 1:(0.1-0.5), and the adamantane modified diamine is a product of an addition reaction of adamantane diamine and an alicyclic diisocyanate in a molar ratio of (1.2-2):1; the general formula of the adamantane diamine is NH2(CH2) n R 1 (CH2) m NH2, R 1 represents an adamantane structure, and n and m are each independently an integer of 0 to 3.

[0008] The second object of the present invention is to provide the use of the above-mentioned high-selectivity spiral membrane in the separation of monosaccharides and polysaccharides.

[0009] The roll membrane provided by the present invention can stably operate at a high flux under high pressure conditions and can be stably used for the separation of monosaccharides and polysaccharides for a long time. DETAILED DESCRIPTION

[0010] The membrane element body of the high-selectivity rolled membrane provided by the present invention comprises a central tube and a membrane sheet group wound on the central tube, the separation membrane of the membrane bag contained in the membrane sheet group is formed by a polyamide separation membrane, and the polyamide separation membrane comprises a porous support layer and a modified polyamide separation layer loaded on the surface of the porous support layer; the modified polyamide separation layer is formed by interfacial polymerization of a complex polyamine and a polyacid chloride in the presence of a humate.

[0011] In the present invention, the composite polyamine is a compound of aliphatic polyamine and adamantane-modified diamine in a mass ratio of 1:(0.1-0.5). The adamantane-modified diamine is an addition reaction product of adamantane diamine and alicyclic diisocyanate. The general formula of adamantane diamine is preferably NH2(CH2) n R 1 (CH2) m NH2, R 1 represents an adamantane structure, and n and m are each independently an integer of 0 to 3, such as 0, 1, 2 or 3. Particularly preferably, the adamantane diamine is 1,3-di(4-aminophenylcyclo)adamantane. The alicyclic diisocyanate is a compound having a carbon ring and at least two isocyanate groups, preferably isophorone diisocyanate and / or cyclohexyl diisocyanate. The molar ratio of the adamantane diamine to the alicyclic diisocyanate is (1.2 to 2):1, such as 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1 or any value therebetween.

[0012] In the present invention, the conditions for the addition reaction preferably include a temperature of 70 to 90°C, such as 70°C, 75°C, 80°C, 85°C, 90°C or any value therebetween; and a time of 10 to 30 min, such as 10 min, 15 min, 20 min, 25 min, 30 min or any value therebetween.

[0013] In the present invention, the composite polyamine is a composite of an aliphatic polyamine and an adamantane-modified diamine. The mass ratio of the aliphatic polyamine to the adamantane-modified diamine is 1:(0.1-0.5), such as 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5 or any value therebetween. Specific examples of the aliphatic polyamine include, but are not limited to, at least one of polyethyleneimine, triethylenetetramine, tetraethylenepentamine, diethylenetriamine, polyethylenepolyamine, piperazine, m-phenylenediamine and p-phenylenediamine.

[0014] In the present invention, specific examples of the polyacyl chloride include, but are not limited to, at least one of trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride and phthaloyl chloride, preferably trimesoyl chloride and / or terephthaloyl chloride. The molar ratio of the acyl chloride group in the polyacyl chloride to the amino group in the composite polyamine is preferably (0.9-1.1):1, such as 0.9:1, 1:1, 1.1:1 or any value therebetween.

[0015] In the present invention, specific examples of the humate include, but are not limited to, at least one of sodium humate, potassium humate and calcium humate. The mass ratio of the humate to the composite polyamine is preferably (0.2-0.6):1, such as 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1 or any value therebetween.

[0016] In the present invention, specific examples of the porous support layer include but are not limited to at least one of a porous polyethersulfone membrane, a porous polysulfone membrane, a porous polyvinylidene fluoride membrane, a porous polyethyleneimine membrane, a porous polyamide membrane, a porous cellulose acetate membrane and a porous polyvinyl nitrile membrane.

[0017] In a preferred embodiment, the interfacial polymerization method includes contacting the porous support layer with the aqueous phase containing the complex polyamine and the oil phase containing the polyacid chloride in sequence, and then performing heat treatment to polymerize the interface on the surface of the porous support layer to obtain a modified polyamide separation layer. Wherein, the time for contacting the porous support layer with the aqueous phase containing the complex polyamine is preferably 1 to 10 minutes, such as 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes or any value therebetween. The time for contacting the porous support layer with the oil phase containing the polyacid chloride is preferably 1 to 10 minutes, such as 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes or any value therebetween. The heat treatment conditions preferably include a temperature of 50 to 150°C, such as 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or any value therebetween; and a time of 0.5 to 10 min, such as 0.5 min, 1 min, 2 min, 4 min, 6 min, 8 min, 10 min or any value therebetween.

[0018] The improvement of the present invention is that a new modified polyamide separation layer is used to form a membrane bag, while the other components of the roll membrane and the connection relationship between the components can be the same as the prior art. Generally, the high-selectivity roll membrane includes a membrane element body and an outer net, the membrane element body includes a central tube and a membrane sheet group wound on the central tube, the membrane sheet group includes a feed liquid grid and a membrane bag, the membrane bag includes a separation membrane and a dialysate grid, the dialysate grid is arranged between two separation membranes, one side of the separation membrane is connected to the central tube and the other sides are sealed. The central tube is provided with a plurality of water outlets, and different water outlets are arranged on the inner side of different membrane bags. The membrane sheet group is spirally wound around the central tube to form a cylindrical membrane element body, and the outer net is wrapped and wound on the surface of the membrane element body to form a shell. A glass fiber reinforced plastic reinforcement layer is usually provided between the membrane element body and the outer net.

[0019] The present invention also provides the use of the high-selectivity rolled membrane in the separation of monosaccharides and polysaccharides.

[0020] The present invention will be described in detail below through examples.

[0021] Preparation Example 1 Preparation of adamantane-modified diamine

[0022] 1.2 mol of 1,3-di(4-aminophenylcyclo)adamantane, 1 mol of isophorone diisocyanate and 100 mL of n-hexane were added into a reaction kettle, reacted at 70° C. for 30 min, and the organic solvent was removed by rotary evaporation to obtain adamantane-modified diamine, which was recorded as JA-1.

[0023] Preparation Example 2 Preparation of Adamantane-modified Diamine

[0024] 2 mol of 1,3-di(4-aminophenylcyclo)adamantane, 1 mol of cyclohexyl diisocyanate and 100 mL of n-hexane were added into a reactor, reacted at 90° C. for 10 min, and the organic solvent was removed by rotary evaporation to obtain adamantane-modified diamine, which was recorded as JA-2.

[0025] Preparation Example 3 Preparation of Adamantane-modified diamine

[0026] 1.5 mol of 1,3-di(4-aminophenylcyclo)adamantane, 1 mol of cyclohexyl diisocyanate and 100 mL of n-hexane were added into a reactor, reacted at 80° C. for 20 min, and the organic solvent was removed by rotary evaporation to obtain adamantane-modified diamine, which was recorded as JA-3.

[0027] Comparative Preparation Example 1

[0028] Adamantane diamine was prepared according to the method of Preparation Example 1, except that isophorone diisocyanate was replaced by the same molar amount of hexamethylene diisocyanate (HDI), and the other conditions were the same as Preparation Example 1 to obtain a reference adamantane modified diamine, which was recorded as DJA-1.

[0029] Example 1 Preparation of separation membrane

[0030] S1. Preparation of a polyamine solution: dissolving polyethyleneimine and adamantane-modified diamine JA-1 in water at a mass ratio of 1:0.1 to obtain a composite polyamine solution with a concentration of 0.5 wt %;

[0031] S1. Immerse the polysulfone support layer in a composite polyamine solution at 25°C. After immersion for 60 seconds, take out the membrane and put it into an IsoparE solution containing 0.02wt% of trimesoyl chloride, 0.08wt% of terephthaloyl chloride and 0.05wt% of potassium humate at 25°C. After immersion for 60 seconds, take out the membrane and then put it into an oven and heat it at 70°C for 30 minutes to obtain a separation membrane.

[0032] Example 2 Preparation of separation membrane

[0033] S1. Preparation of a polyamine solution: dissolving m-phenylenediamine and adamantane-modified diamine JA-2 in water at a mass ratio of 1:0.5 to obtain a composite polyamine solution with a concentration of 1 wt %;

[0034] S1. The polysulfone support layer is immersed in a composite polyamine solution at 25°C. After immersion for 5 minutes, the membrane is taken out and placed in an Isopar E solution containing 0.1wt% of trimesoyl chloride and 0.05wt% of sodium humate at 25°C. After immersion for 5 minutes, the membrane is taken out and then placed in an oven and heated at 90°C for 10 minutes to obtain a separation membrane.

[0035] Example 3 Preparation of separation membrane

[0036] S1. Preparation of a polyamine solution: dissolving triethylenetetramine and adamantane-modified diamine JA-3 in water at a mass ratio of 1:0.2 to obtain a composite polyamine solution with a concentration of 1 wt %;

[0037] S1. The polysulfone support layer is immersed in a composite polyamine solution at 25°C. After immersion for 3 minutes, the membrane is taken out and placed in an Isopar E solution containing 0.1wt% terephthaloyl chloride and 0.05wt% sodium humate at 25°C. After immersion for 3 minutes, the membrane is taken out and then placed in an oven and heated at 80°C for 20 minutes to obtain a separation membrane.

[0038] Comparative Example 1

[0039] A separation membrane was prepared according to the method of Example 1, except that the adamantane-modified diamine JA-1 was replaced by polyethyleneimine in the same weight portion. The remaining conditions were the same as those of Example 1 to obtain a separation membrane.

[0040] Comparative Example 2

[0041] A separation membrane was prepared according to the method of Example 1, except that polyethyleneimine was replaced by the same weight portion of adamantane-modified diamine JA-1. The remaining conditions were the same as those of Example 1 to obtain a separation membrane.

[0042] Comparative Example 3

[0043] A separation membrane was prepared according to the method of Example 1, except that the adamantane-modified diamine JA-1 was replaced by the reference adamantane-modified diamine DJA-1 in the same weight portion, and the other conditions were the same as in Example 1 to obtain a separation membrane.

[0044] Comparative Example 4

[0045] A separation membrane was prepared according to the method of Example 1, except that no sodium humate was added to the Isopar E solution. The other conditions were the same as those of Example 1, and a separation membrane was obtained.

[0046] Test Case

[0047] (1) The separation membranes obtained in the above embodiments and comparative examples were placed in a membrane pool and pre-pressed at 2 MPa for 1 h. The water permeation of the separation membrane was then measured at a pressure of 70 MPa and a temperature of 25° C. within a certain period of time. The water flux was calculated by the following formula: J = Q / (A·t), where J is the water flux, Q is the water permeation (L), and A is the effective membrane area (m 2 ), t is time (h). After 30 days of continuous operation, the water flux was calculated again using the same method and the same conditions. The results are shown in Table 1.

[0048] (2) The separation membranes obtained in the above examples and comparative examples were loaded into a membrane pool. The raw sugar solution was a complex sugar solution of glucose and sucrose in a mass ratio of 1:1. The concentration of the complex sugar solution was 2000 ppm. After pre-pressing at 2 MPa for 1 h, the permeate was obtained under the conditions of a pressure of 70 MPa and a temperature of 25° C. The monosaccharide permeability was calculated by the following formula: R = C p / C f ×100%, where R is the monosaccharide permeability, C f is the concentration of monosaccharides in the raw sugar solution, C p is the concentration of monosaccharides in the corresponding permeate; the polysaccharide permeability is calculated by the following formula: R`=C p ` / C f `×100%, where R` is the polysaccharide permeability, Cf ` is the concentration of polysaccharide in the raw sugar solution, C p ` is the concentration of polysaccharide in the corresponding permeate. After 30 days of continuous operation, the monosaccharide and polysaccharide permeabilities were calculated again using the same method and the same conditions. The results are shown in Table 1.

[0049]

[0050] As can be seen from the results of Table 1, the roll membrane provided by the present invention can still operate stably at high flux for a long time after the operating pressure is increased to high pressure, and can effectively separate monosaccharides and polysaccharides. From the comparison of Example 1 and Comparative Example 1, it can be seen that when the adamantane-modified diamine is not used in the formation process of the separation membrane, although the initial flux is very high, it drops sharply after running for a period of time, and both monosaccharides and polysaccharides can pass through the separation membrane, and monosaccharides and polysaccharides cannot be effectively separated. From the comparison of Example 1 and Comparative Example 2, it can be seen that when aliphatic polyamines are not used in the formation process of the separation membrane, although monosaccharides and polysaccharides can be separated, the flux is low and the separation speed is slow. From the comparison of Example 1 and Comparative Example 3, it can be seen that when alicyclic diisocyanates are not used in the formation process of the separation membrane, although the initial flux is very high, it drops significantly after running for a period of time, and both monosaccharides and polysaccharides can pass through the separation membrane, and monosaccharides and polysaccharides cannot be effectively separated. From the comparison between Example 1 and Comparative Example 4, it can be seen that when humate is not added during the formation of the separation membrane, although the initial flux is very high and can separate monosaccharides and polysaccharides, it drops sharply after running for a period of time. At the same time, polysaccharides can slowly pass through the separation membrane as the running time increases, and monosaccharides and polysaccharides cannot be separated after long-term use.

[0051] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A high-selectivity spiral membrane, wherein the membrane element body of the high-selectivity spiral membrane comprises a central tube and a membrane sheet group wound on the central tube, characterized in that: The separation membrane of the membrane bag contained in the membrane sheet group is formed by a polyamide separation membrane, and the polyamide separation membrane comprises a porous support layer and a modified polyamide separation layer supported on the surface of the porous support layer; The modified polyamide separation layer is formed by interfacial polymerization of a composite polyamine and a polyacyl chloride in the presence of a humic acid salt, wherein the composite polyamine is a composite of an aliphatic polyamine and an adamantane-modified diamine in a mass ratio of 1:(0.1-0.5), and the adamantane-modified diamine is a product of an addition reaction of adamantane diamine and an alicyclic diisocyanate in a molar ratio of (1.2-2):1; the general formula of the adamantane diamine is NH2(CH2) n R 1 (CH2) m NH2, R 1 represents an adamantane structure, n and m are each independently an integer of 0 to 3; and the alicyclic diisocyanate is isophorone diisocyanate and / or cyclohexyl diisocyanate.

2. The highly selective roll-type membrane according to claim 1, characterized in that: The adamantane diamine is 1,3-di(4-aminophenyl ring)adamantane.

3. The highly selective rolled membrane according to claim 1, characterized in that: The conditions of the addition reaction include a temperature of 70-90° C. and a time of 10-30 min.

4. The highly selective wound membrane according to claim 1, characterized in that: The aliphatic polyamine is at least one selected from polyethyleneimine, triethylenetetramine, tetraethylenepentamine, diethylenetriamine, polyethylenepolyamine, piperazine, m-phenylenediamine and p-phenylenediamine.

5. The highly selective wound membrane according to claim 1, characterized in that: The polyacid chloride is selected from at least one of trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride and phthaloyl chloride.

6. The highly selective wound membrane according to claim 5, characterized in that: The polyacid chloride is trimesoyl chloride and / or terephthaloyl chloride.

7. The highly selective wound membrane according to claim 1, characterized in that: The humate is selected from at least one of sodium humate, potassium humate and calcium humate.

8. The highly selective wound membrane according to claim 1, characterized in that: The porous supporting layer is selected from at least one of a porous polyethersulfone membrane, a porous polysulfone membrane, a porous polyvinylidene fluoride membrane, a porous polyethyleneimine membrane, a porous polyamide membrane, a porous cellulose acetate membrane and a porous polyvinyl nitrile membrane.

9. The highly selective wound membrane according to claim 1, characterized in that: The interfacial polymerization method includes sequentially contacting the porous support layer with an aqueous phase containing a complex polyamine and an oil phase containing polyacid chloride, and then performing heat treatment to polymerize the interface on the surface of the porous support layer to obtain a modified polyamide separation layer.

10. The highly selective wound membrane according to claim 9, characterized in that: The porous support layer is in contact with the water phase containing the complex polyamine for 1 to 10 minutes; the porous support layer is in contact with the oil phase containing the polyacid chloride for 1 to 10 minutes.

11. The highly selective wound membrane according to claim 9, characterized in that: The heat treatment conditions include a temperature of 50-150° C. and a time of 0.5-10 min.

12. Use of the highly selective spiral membrane according to any one of claims 1 to 11 in the separation of monosaccharides and polysaccharides.

Images