A kind of environmentally friendly production method of inositol

Abstract

The invention discloses a kind of environmentally friendly production method of inositol, comprising the following steps: after neutralizing the phytin hydrolyzate, filtering, cooling and filtering after the filtrate is concentrated by a multi-effect concentration system, the filtrate after cooling and filtering enters into a chromatographic separation system for separation, and collects the inositol phase and the salt phase; the salt phase is concentrated and crystallized to obtain a byproduct of potassium chloride; the collected inositol phase is processed by a cation exchange resin column, an anion exchange resin column, and a weakly polar macroporous adsorption resin column connected in series successively, and a pure inositol solution is obtained; after the inositol solution is concentrated by a nanofiltration membrane, a nanofiltration membrane concentrate is obtained, and the nanofiltration membrane concentrate is pumped into a multi-effect vacuum concentrator for secondary concentration treatment to obtain an inositol concentrate; after the inositol concentrate is finely filtered, it enters into a spray fluidized granulation tower for treatment to obtain an inositol finished product. The present invention does not need to add activated carbon for decolorization treatment, avoids the generation of a large amount of solid waste and the loss of inositol, and does not produce a crystallization mother liquor, thereby improving the yield of inositol.

Description

Technical Field

[0001] The invention relates to the technical field of inositol preparation, and in particular to an environmentally friendly production method of inositol. Background Art

[0002] Inositol is an important vitamin required by higher animals. Inositol can promote fat metabolism and reduce the cholesterol content in the blood. It is also used as an anti-fatty liver drug for the treatment of cirrhosis, hepatitis, high cholesterol, excessive fat and vascular sclerosis. In addition to being used directly as a drug, such as inositol tablets, hepatol, and liver-soothing tablets, inositol is also used as a pharmaceutical intermediate to make many drugs, such as nicotinic acid inositol ester, Maitong, and the anticancer drug paclitaxel.

[0003] The current inositol production process generally includes the processes of hydrolysis of phytin, concentration, crude crystallization, decolorization, recrystallization, centrifugation, and drying. There are the following defects: the soluble impurities such as potassium chloride and protein contained in phytin interfere with the crystallization of inositol and reduce the crystallization yield. When the impurity concentration in the inositol crystallization mother liquor is too high, inositol cannot be crystallized and can only be discharged as waste liquid; the crude product is decolorized with activated carbon, which produces solid waste and carries inositol with it, affecting the yield; and the inositol yield in the recrystallization process is 60-70%, and the crystallization mother liquor needs to be returned to the previous process for treatment, which increases the cost and there will be inositol loss in the process. In addition, inositol drying mostly adopts drying methods such as ovens and fluidized beds. There are many lumps of materials after drying, which need to be crushed and screened and packaged. Since inositol crystalline particles are brittle and fragile, a large amount of fine powder is easily generated during the crushing and pipeline transportation process, which not only causes dust to fly in the crushing, screening, packaging and other processes, a poor working environment and large product losses; but also because the fine powder accounts for a large proportion of the product, the fluidity is poor, and it is easy to absorb moisture and agglomerate, which is inconvenient for downstream manufacturers to use. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, an environmentally friendly production method of inositol is provided. The method purifies the inositol liquid by combining a chromatographic separation system, a cation exchange resin, an anion exchange resin and a weakly polar macroporous adsorption resin, and does not require the addition of activated carbon for decolorization treatment, thereby avoiding the generation of a large amount of solid waste and the loss of inositol, and no crystallization mother liquor is generated, thereby improving the yield of inositol.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] An environmentally friendly production method of inositol comprises the following steps:

[0007] (1) neutralizing the phytin hydrolyzate and filtering it, concentrating the filtrate through a multi-effect concentration system and then cooling and filtering it, and the filtrate after cooling and filtering enters a chromatographic separation system for separation, and collecting an inositol phase and a salt phase;

[0008] (2) the collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution;

[0009] (3) concentrating the inositol solution through a nanofiltration membrane to obtain a nanofiltration membrane concentrate, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration to obtain an inositol concentrate;

[0010] (4) The inositol concentrate is finely filtered and then sent to a spray fluidized granulation tower for treatment to obtain an inositol finished product.

[0011] As a preferred embodiment of the above technical solution, in step (1), during neutralization, alkaline calcium salt is added to the phytin hydrolyzate to neutralize the phytin hydrolyzate until the pH value of the phytin hydrolyzate is 9-11, and the alkaline calcium salt is a mixture of one or more of calcium hydroxide, calcium carbonate and calcium bicarbonate.

[0012] As a preferred embodiment of the above technical solution, in step (1), plate and frame filtration is adopted for filtration, and the pore size of the filter cloth is 300-400 mesh; the temperature during cooling filtration is 50-60°C, the filter medium is filter paper board, and the pore size of the filter paper board is 1-5μm.

[0013] As a preferred embodiment of the above technical solution, in step (1), the vacuum degree of the multi-effect concentration system during concentration is -0.07MPa to -0.09MPa, the temperature is 80-90°C, and the solid content of the concentrated liquid is 20-25%.

[0014] As a preferred embodiment of the above technical scheme, in step (1), the mobile phase during separation in the chromatographic separation system is purified water, the volume of the mobile phase to the filtrate is (2-3):1, the separation pressure is 0-0.6Mpa, the separation temperature is 40-60°C, the filtrate flow rate is 20-50L / h, the mobile phase flow rate is 100-160L / h, the valve switching time is 4-8min, and the volume ratio of the inositol phase to the salt phase is (2-3):1.

[0015] As a preferred embodiment of the above technical solution, in step (2), the cation exchange resin, the anion exchange resin and the weakly polar macroporous adsorption resin are all high temperature resistant resins, and their operating temperature is 50-60°C.

[0016] As a preferred embodiment of the above technical solution, in step (2), the volumes of the cation exchange resin, the anion exchange resin and the weakly polar macroporous adsorption resin are the same, and the feed amount of the cation exchange resin is 10-20 BV of the volume of the cation exchange resin.

[0017] As a preferred embodiment of the above technical solution, in step (3), the pore size of the nanofiltration membrane is 100-200D, the operating pressure is 0.3-0.6MPa, and the solid content of the nanofiltration membrane concentrate is 20-25%; the vacuum degree during the secondary concentration treatment is -0.07 to -0.09MPa, the temperature is 80-90°C, and the solid content of the inositol concentrate is 45-55%.

[0018] As a preferred embodiment of the above technical solution, in step (4), the filter element pore size of the precision filter used for precision filtration is 0.5-1μm; the spray fluidized bed granulation tower is a pressure spray tower, and the feed pressure of the spray fluidized bed granulation tower during treatment is 1-2MPa, the inlet air temperature is 160-185℃, and the outlet air temperature is 75-85℃.

[0019] Furthermore, the conductivity of the inositol phase of the present invention is 1000-3000 μS / cm, and the transmittance is 40-70%; the conductivity of the weak polar macroporous adsorption resin output is 1-20 μS / cm, and the transmittance is 98-100%.

[0020] Among the inositol products prepared by the invention, the products with a particle size of 30-80 meshes account for ≥80%.

[0021] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] The present invention uses phytin hydrolyzate as a raw material, adds alkaline calcium salt for neutralization, and then removes saturated tricalcium phosphate by filtering. The filtrate is concentrated by a multi-effect concentration system and then cooled and filtered to continue to remove part of the tricalcium phosphate, while increasing the inositol concentration and reducing the amount of water used in subsequent chromatographic separation. The present invention sequentially processes the inositol phase after chromatographic separation through a cation exchange resin column, an anion exchange resin column, and a weakly polar macroporous adsorption resin column to obtain a pure inositol solution. The present invention thoroughly removes impurities in an inositol slurry by combining a chromatographic separation system, a cation exchange resin, an anion exchange resin and a weakly polar macroporous adsorption resin. The chromatographic separation system can separate most of the impurities such as salts, pigments, amino acids and the like in the slurry into a salt phase. A small amount of salts and charged organic impurities remaining in the inositol phase are further adsorbed by a cation exchange resin column and an anion exchange resin column, and weakly polar and non-polar organic impurities are further adsorbed by the weakly polar macroporous adsorption resin. The impurity content in the obtained inositol solution is extremely low, and there is no need to add a decolorizing agent such as activated carbon. A high-quality inositol finished product can be obtained by direct concentration and drying, thereby avoiding the generation of solid waste and the loss of inositol.

[0023] The chromatographic separation and desalination method of the present invention has low operating costs, and only water is used to achieve most of the separation of inositol and impurities. The resin regeneration cycle is long, and the regeneration cycle is generally 6-12 months according to the material conditions, and the ion exchange resin needs to be regenerated for each batch of materials, and a large amount of acid-base wastewater is generated during regeneration. Therefore, the use of chromatographic separation and ion exchange resin combined desalination can effectively reduce the amount of resin, the amount of regeneration agent used, and the amount of wastewater discharged. The salt phase after chromatographic separation is collected and concentrated and crystallized, and potassium chloride is recovered to improve production efficiency.

[0024] In addition, the present invention combines the nanofiltration membrane concentration and vacuum concentration of the pure inositol solution, which greatly reduces the energy consumption of concentration. The concentrated inositol concentrated solution is transported to the upper atomizer of the spray fluidized granulation tower by a feed pump after precision filtration, and the generated atomized droplets meet the high-temperature dry airflow, and the water evaporates to form small particles. When the particles enter the built-in fluidized bed of the granulation tower, the airflow reverses and moves upward, and is discharged from the top of the drying tower. The fine powder is driven by the rising airflow and repolymerizes with the droplets to form dry particles, so that drying and granulation are formed in one step, and the operation is convenient. The prepared inositol particles have uniform particle size, good fluidity, and are not easy to absorb moisture, so that the dust phenomenon when the material is broken is avoided, and it is convenient for downstream manufacturers to realize automatic transportation.

[0025] Compared with the traditional process of crude product crystallization and recrystallization after crude product decolorization, the inositol solution in the present invention has extremely low impurity content after purification, can be completely dried to obtain the finished product, no crystallization mother liquor is produced, and the inositol finished product has a high yield and high purity; the method provided by the present invention can be manufactured using automated production equipment, which greatly reduces labor costs. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0027] Example 1

[0028] (1) adding calcium hydroxide to the fitin hydrolyzate to neutralize the pH of the fitin hydrolyzate to 9-11, then filtering the filter cloth with a pore size of 300 meshes using a plate and frame filter, concentrating the filtrate through a multi-effect concentration system under the conditions of a vacuum degree of -0.07 MPa and a temperature of 80°C to obtain a concentrate with a solid content of 20-25%, cooling the concentrate to 50°C and filtering it through a filter paper with a pore size of 1 μm, and the filtrate entering a chromatographic separation system for separation to collect an inositol phase and a salt phase; the mobile phase during separation in the chromatographic separation system is purified water, the volume of the mobile phase to the filtrate is 2:1, the separation pressure is 0.3 MPa, the separation temperature is 40°C, the filtrate flow rate is 20 L / h, the mobile phase flow rate is 100 L / h, and the valve switching time is 4 min;

[0029] (2) The collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution; the feed amount of the cation exchange resin is 10 BV of the resin volume;

[0030] (3) using a nanofiltration membrane with a pore size of 100D to concentrate the inositol solution at an operating pressure of 0.3 MPa to obtain a nanofiltration membrane concentrate with a solid content of 20-25%, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration treatment at a vacuum degree of -0.07 MPa and a temperature of 80° C. to obtain an inositol concentrate with a solid content of 45-55%;

[0031] (4) The inositol concentrate is filtered through a precision filter with a filter element pore size of 0.5 μm and then enters a spray fluidized bed granulation tower for treatment. During the treatment, the feed pressure of the spray fluidized bed granulation tower is 1 MPa, the inlet air temperature is 160° C., and the outlet air temperature is 75° C. to obtain an inositol finished product.

[0032] Example 2

[0033] (1) adding calcium carbonate to the fitin hydrolyzate to neutralize the pH of the fitin hydrolyzate to 9-11, then filtering the filter cloth with a pore size of 400 meshes using a plate and frame filter, concentrating the filtrate through a multi-effect concentration system under the conditions of a vacuum degree of -0.09 MPa and a temperature of 90° C. to obtain a concentrate with a solid content of 20-25%, cooling the concentrate to 60° C. and filtering it through a filter paper with a pore size of 5 μm, and the filtrate entering a chromatographic separation system for separation to collect an inositol phase and a salt phase; the mobile phase during separation in the chromatographic separation system is purified water, the volume ratio of the mobile phase to the filtrate is 3:1, the separation pressure is 0.6 MPa, the separation temperature is 60° C., the filtrate flow rate is 50 L / h, the mobile phase flow rate is 160 L / h, and the valve switching time is 8 min;

[0034] (2) The collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution; the feed amount of the cation exchange resin is 20 BV of the resin volume;

[0035] (3) using a nanofiltration membrane with a pore size of 200D to concentrate the inositol solution at an operating pressure of 0.6 MPa to obtain a nanofiltration membrane concentrate with a solid content of 20-25%, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration treatment at a vacuum degree of -0.09 MPa and a temperature of 90° C. to obtain an inositol concentrate with a solid content of 45-55%;

[0036] (4) The inositol concentrate is filtered through a precision filter with a filter element pore size of 1 μm and then enters a spray fluidized bed granulation tower for treatment. During the treatment, the feed pressure of the spray fluidized bed granulation tower is 2 MPa, the inlet air temperature is 185° C., and the outlet air temperature is 85° C. to obtain an inositol finished product.

[0037] Example 3

[0038] (1) adding calcium bicarbonate to the fitin hydrolyzate to neutralize it to a pH of 9-11, then filtering it with a plate-and-frame filter having a filter cloth with a pore size of 350 mesh, concentrating the filtrate with a multi-effect concentration system under the conditions of a vacuum degree of -0.08 MPa and a temperature of 80°C to obtain a concentrate with a solid content of 20-25%, cooling the concentrate to 50°C and filtering it with a filter paper having a pore size of 2 μm, and the filtrate entering a chromatographic separation system for separation to collect an inositol phase and a salt phase; the mobile phase for separation in the chromatographic separation system is purified water, the volume ratio of the mobile phase to the filtrate is 2:1, the separation pressure is 0.2 MPa, the separation temperature is 50°C, the filtrate flow rate is 30 L / h, the mobile phase flow rate is 120 L / h, and the valve switching time is 5 min;

[0039] (2) The collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution; the feed amount of the cation exchange resin is 15 BV of the resin volume;

[0040] (3) using a nanofiltration membrane with a pore size of 100D to concentrate the inositol solution at an operating pressure of 0.5 MPa to obtain a nanofiltration membrane concentrate with a solid content of 20-25%, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration treatment at a vacuum degree of -0.07 MPa and a temperature of 90° C. to obtain an inositol concentrate with a solid content of 45-55%;

[0041] (4) The inositol concentrate is filtered through a precision filter with a filter element pore size of 0.7 μm and then enters a spray fluidized bed granulation tower for treatment. During the treatment, the feed pressure of the spray fluidized bed granulation tower is 1.5 MPa, the inlet air temperature is 170° C., and the outlet air temperature is 80° C. to obtain an inositol finished product.

[0042] Example 4

[0043] (1) adding calcium hydroxide to the fitin hydrolyzate to neutralize the pH of the fitin hydrolyzate to 9-11, then filtering the filter cloth with a pore size of 400 meshes using a plate and frame filter, concentrating the filtrate through a multi-effect concentration system under the conditions of a vacuum degree of -0.09 MPa and a temperature of 85°C to obtain a concentrate with a solid content of 20-25%, cooling the concentrate to 55°C and filtering it through a filter paper with a pore size of 3 μm, and the filtrate entering a chromatographic separation system for separation to collect an inositol phase and a salt phase; the mobile phase for separation in the chromatographic separation system is purified water, the volume ratio of the mobile phase to the filtrate is 3:1, the separation pressure is 0.4 MPa, the separation temperature is 50°C, the filtrate flow rate is 40 L / h, the mobile phase flow rate is 140 L / h, and the valve switching time is 5 min;

[0044] (2) The collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution; the feed amount of the cation exchange resin is 20 BV of the resin volume;

[0045] (3) using a nanofiltration membrane with a pore size of 200D to concentrate the inositol solution at an operating pressure of 0.5 MPa to obtain a nanofiltration membrane concentrate with a solid content of 20-25%, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration treatment at a vacuum degree of -0.08 MPa and a temperature of 90° C. to obtain an inositol concentrate with a solid content of 45-55%;

[0046] (4) The inositol concentrate is filtered through a precision filter with a filter element pore size of 0.8 μm and then enters a spray fluidized bed granulation tower for treatment. During the treatment, the feed pressure of the spray fluidized bed granulation tower is 2 MPa, the inlet air temperature is 160° C., and the outlet air temperature is 80° C. to obtain an inositol finished product.

[0047] Example 5

[0048] (1) adding calcium bicarbonate to the fitin hydrolyzate to neutralize it to a pH of 9-11, then filtering it with a plate-and-frame filter having a filter cloth with a pore size of 400 mesh, concentrating the filtrate with a multi-effect concentration system under the conditions of a vacuum degree of -0.07 MPa and a temperature of 90° C. to obtain a concentrate with a solid content of 20-25%, cooling the concentrate to 60° C. and filtering it with a filter paper having a pore size of 4 μm, and the filtrate entering a chromatographic separation system for separation, collecting an inositol phase and a salt phase; the mobile phase for separation in the chromatographic separation system is purified water, the volume ratio of the mobile phase to the filtrate is 3:1, the separation pressure is 0.5 MPa, the separation temperature is 50° C., the filtrate flow rate is 40 L / h, the mobile phase flow rate is 150 L / h, and the valve switching time is 7 min;

[0049] (2) The collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution; the feed amount of the cation exchange resin is 10 BV of the resin volume;

[0050] (3) using a nanofiltration membrane with a pore size of 200D to concentrate the inositol solution at an operating pressure of 0.3 MPa to obtain a nanofiltration membrane concentrate with a solid content of 20-25%, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration treatment at a vacuum degree of -0.09 MPa and a temperature of 80° C. to obtain an inositol concentrate with a solid content of 45-55%;

[0051] (4) The inositol concentrate is filtered through a precision filter with a filter element pore size of 0.5 μm and then enters a spray fluidized bed granulation tower for treatment. During the treatment, the feed pressure of the spray fluidized bed granulation tower is 1 MPa, the inlet air temperature is 160° C., and the outlet air temperature is 85° C. to obtain an inositol finished product.

[0052] The conductivity of the inositol phase obtained in the above embodiment is 1000-3000 μS / cm, and the transmittance is 40-70%; the conductivity of the weakly polar macroporous adsorption resin output is 1-20 μS / cm, and the transmittance is 98-100%; the product with a particle size of 30-80 mesh in the obtained inositol product accounts for ≥80%; the purity of inositol is ≥99.5%; the yield of inositol is ≥95%.

[0053] In addition, it should be understood that after reading the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. An environmentally friendly method for producing inositol, characterized in that: The following steps are involved: (1) neutralizing the phytin hydrolyzate and filtering it, concentrating the filtrate through a multi-effect concentration system and then cooling and filtering it, and the filtrate after cooling and filtering enters a chromatographic separation system for separation, and collecting an inositol phase and a salt phase; The mobile phase during separation in the chromatographic separation system is purified water, the volume of the mobile phase to the filtrate is (2-3):1, the separation pressure is 0-0.6Mpa, the separation temperature is 40-60°C, the filtrate flow rate is 20-50L / h, the mobile phase flow rate is 100-160L / h, the valve switching time is 4-8min, and the volume ratio of the inositol phase to the salt phase is (2-3):1; (2) the collected salt phase is concentrated and crystallized to obtain potassium chloride as a byproduct; the collected inositol phase is treated with a cation exchange resin column, an anion exchange resin column and a weak polar macroporous adsorption resin column connected in series to obtain a pure inositol solution; (3) concentrating the inositol solution through a nanofiltration membrane to obtain a nanofiltration membrane concentrate, and pumping the nanofiltration membrane concentrate into a multi-effect vacuum concentrator for secondary concentration to obtain an inositol concentrate; (4) The inositol concentrate is finely filtered and then sent to a spray fluidized granulation tower for treatment to obtain an inositol finished product.

2. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (1), during neutralization, alkaline calcium salt is added to the phytin hydrolyzate to neutralize until the pH of the phytin hydrolyzate is 9-11, and the alkaline calcium salt is a mixture of one or more of calcium hydroxide, calcium carbonate and calcium bicarbonate.

3. An environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (1), plate and frame filtration is used for filtration, and the pore size of the filter cloth is 300-400 mesh; the temperature during cooling filtration is 50-60° C., and the filter medium is a filter paper board, and the pore size of the filter paper board is 1-5 μm.

4. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (1), the vacuum degree of the multi-effect concentration system during concentration is -0.07MPa to -0.09MPa, the temperature is 80-90°C, and the solid content of the concentrated liquid is 20-25%.

5. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (2), the cation exchange resin, the anion exchange resin and the weakly polar macroporous adsorption resin are all high temperature resistant resins, and their operating temperature is 50-60°C.

6. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (2), the volumes of the cation exchange resin, the anion exchange resin and the weakly polar macroporous adsorption resin are the same, and the feed amount of the cation exchange resin is 10-20 BV of the volume of the cation exchange resin.

7. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (3), the pore size of the nanofiltration membrane is 100-200D, the operating pressure is 0.3-0.6MPa, and the solid content of the nanofiltration membrane concentrate is 20-25%.

8. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (3), the vacuum degree during the secondary concentration treatment is -0.07 to -0.09 MPa, the temperature is 80-90° C., and the solid content of the inositol concentrate is 45-55%.

9. The environmentally friendly method for producing inositol according to claim 1, characterized in that: In step (4), the filter element pore size of the precision filter used for precision filtration is 0.5-1μm; the spray fluidized bed granulation tower is a pressure spray tower, and the feed pressure of the spray fluidized bed granulation tower during treatment is 1-2MPa, the inlet air temperature is 160-185℃, and the outlet air temperature is 75-85℃.