A processing method for phytin hydrolyzate

Abstract

The invention discloses a method for treating a phytin hydrolyzate, comprising the following steps: filtering the phytin hydrolyzate, collecting a first filtrate and a first filter cake; pumping the first filtrate into a neutralization tank, adding lime milk to adjust the pH of the first filtrate, filtering, washing the filter cake with water during filtering, collecting a second filtrate and a second filter cake, and drying the second filter cake to obtain dihydrated calcium hydrogen phosphate; mixing the first filter cake and the second filtrate, adding lime milk to adjust the pH of the system, filtering, washing the filter cake with water during filtering, collecting a third filtrate and a third filter cake; drying the third filter cake and then calcining it to obtain solid tricalcium phosphate; concentrating, crystallizing, decolorizing, and refining the third filtrate to obtain inositol. The method provided by the present invention obtains two byproducts, dihydrated calcium hydrogen phosphate and tricalcium phosphate, without affecting the yield of inositol, and reduces air pollution and energy consumption while obtaining high-value byproducts, which is more economical and environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of inositol production, and in particular to a method for treating a phytin hydrolyzate. Background Art

[0002] Inositol is usually produced by hydrolyzing phytin under high temperature and high pressure, and phosphate byproducts are produced during the preparation process. At present, when producing inositol, phytin hydrolyzate and lime water are usually mixed to react to generate tricalcium phosphate insolubles, which are then filtered through a plate and frame filter. The filter cake obtained by filtration is dried and calcined to obtain the byproduct tricalcium phosphate, and the filtrate is post-treated to obtain inositol.

[0003] Although the above method can obtain high-yield and high-purity inositol, it has the following problems: 1. Polluted gas and unpleasant odor will be generated when the filter cake is dried and calcined, which is harmful to the environment; 2. High energy consumption will increase the preparation cost of inositol; 3. The economic value of the by-product tricalcium phosphate is low. 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, a method for treating a phytin hydrolyzate is provided. The method obtains a byproduct of calcium hydrogen phosphate dihydrate with higher economic value by effectively controlling conditions, reduces the processing volume of the tricalcium phosphate calcining process, reduces the discharge of waste, is more conducive to environmental protection, and effectively saves the processing cost of the phytin hydrolyzate.

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

[0006] A method for treating a phytin hydrolyzate comprises the following steps:

[0007] (1) filtering the phytin hydrolyzate to collect a first filtrate and a first filter cake;

[0008] (2) pumping the first filtrate into a neutralization tank, adding lime milk to the neutralization tank to adjust the pH of the first filtrate, stirring and filtering, washing the filter cake with water, collecting the second filtrate and the second filter cake, washing the second filter cake with water and drying to obtain a byproduct of calcium hydrogen phosphate dihydrate;

[0009] (3) mixing the first filter cake and the second filtrate, then adding lime milk to adjust the pH of the system, stirring and filtering, washing the filter cake with water, collecting the third filtrate and the third filter cake, and the third filtrate is the low concentration inositol solution;

[0010] (4) drying the third filter cake and then calcining it to obtain solid tricalcium phosphate;

[0011] (5) The low concentration inositol solution is concentrated, crystallized, decolorized and refined to obtain inositol.

[0012] As a preferred embodiment of the above technical solution, in step (1), the phytin hydrolyzate is prepared by mixing phytin and water to obtain phytin slurry, and then pumping the phytin slurry into a hydrolysis tank for hydrolysis at a certain temperature and a certain pressure.

[0013] As a preferred embodiment of the above technical solution, the mass ratio of fitin to water is 1:(1-2).

[0014] As a preferred embodiment of the above technical solution, the hydrolysis temperature is 160-180°C, the pressure is 0.6-1.0 MPa, and the time is 9-11 hours.

[0015] As a preferred embodiment of the above technical solution, in step (2) and step (3), the lime milk is prepared by mixing lime and water in a mass ratio of 1:(2-3).

[0016] As a preferred embodiment of the above technical solution, in step (2), the system temperature is maintained below 65°C when the lime milk is added dropwise.

[0017] As a preferred embodiment of the above technical solution, in step (2), lime milk is added to adjust the pH of the first filtrate to 6.0-6.5.

[0018] As a preferred embodiment of the above technical solution, in step (2), the temperature of the washing water when the second filter cake is washed with water is 50-60°C.

[0019] As a preferred embodiment of the above technical solution, in step (3), lime milk is added to adjust the pH of the system to 9-11.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] When the present invention uses phytin as a raw material to prepare inositol, phytin and water are firstly mixed and hydrolyzed under certain conditions, the hydrolyzate is filtered, and the filtrate and the filter cake are collected, the filtrate is added with lime milk and reacted under certain conditions to obtain a by-product of dibasic calcium phosphate dihydrate, and the filter cake is subsequently treated to obtain inositol and a by-product of tricalcium phosphate respectively. Through the above conditions, the present invention obtains two by-products of dibasic calcium phosphate dihydrate and tricalcium phosphate, the economic value of dibasic calcium phosphate dihydrate is better, the preparation process is more environmentally friendly, and the preparation cost is lower.

[0022] The method provided by the present invention reduces the subsequent calcination amount of tricalcium phosphate and the emission of pollutant gases without affecting the yield of inositol, is more environmentally friendly, and also obtains dihydrated calcium hydrogen phosphate with higher economic value, thereby improving the company's economic benefits and achieving the purpose of energy conservation and emission reduction. DETAILED DESCRIPTION

[0023] 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.

[0024] Example 1

[0025] (1) adding 1000 g of phytin and 1 L of water into a hydrolysis kettle, and performing hydrolysis at 160° C. and 0.8 MPa for 10.5 h. After the hydrolysis is completed, the hydrolyzate obtained is filtered to collect the first filtrate and the first filter cake;

[0026] (2) pumping the first filtrate obtained in step (1) into a neutralization tank, adding lime and water in a mass ratio of 1:2.5 to the neutralization tank while stirring to adjust the pH of the first filtrate to 6.1, filtering after the pH of the system is stable, compacting the filter cake as much as possible and draining it, washing the filter cake with 50-60° C. water, collecting the second filtrate and the second filter cake, crushing the second filter cake and drying it in a low-temperature oven at 65° C. to obtain 79.7 g of dihydrated calcium hydrogen phosphate as a by-product;

[0027] (3) mixing the first filter cake of step (1) and the second filtrate obtained in step (2), then adding lime milk obtained by mixing lime and water in a mass ratio of 1:2.5 to adjust the pH of the system to 10.1, stirring, filtering after the pH of the system stabilizes, washing the filtered filter cake with water, and collecting a third filtrate and a third filter cake, wherein the third filtrate is a low-concentration inositol solution;

[0028] (4) drying the third filter cake obtained in step (3) at high temperature and then calcining it to obtain 147.2 g of solid tricalcium phosphate;

[0029] (5) The low-concentration inositol solution obtained in step (3) is concentrated, crystallized, decolorized, and refined to obtain inositol. After testing, the inositol yield is 96-97%.

[0030] In summary, after the above process, the by-products obtained contain about 35 wt% of dibasic calcium phosphate dihydrate and about 65 wt% of tricalcium phosphate.

[0031] Example 2

[0032] (1) adding 1000 g of phytin and 1 L of water into a hydrolysis kettle, and performing hydrolysis at 160° C. and 0.7 MPa for 11 h. After the hydrolysis is completed, the hydrolyzate obtained is filtered to collect the first filtrate and the first filter cake;

[0033] (2) pumping the first filtrate obtained in step (1) into a neutralization tank, adding lime milk obtained by mixing lime and water in a mass ratio of 1:2.5 into the neutralization tank while stirring, adjusting the pH of the first filtrate to 6.0, filtering after the pH of the system is stable, compacting the filter cake as much as possible and draining it, washing the filter cake with 50-60° C. water, collecting the second filtrate and the second filter cake, crushing the second filter cake and drying it in a low-temperature oven at 65° C. to obtain 88.9 g of dihydrated calcium hydrogen phosphate as a by-product;

[0034] (3) mixing the first filter cake of step (1) and the second filtrate obtained in step (2), then adding lime milk obtained by mixing lime and water in a mass ratio of 1:2.5 to adjust the pH of the system to 10.2, stirring, filtering after the pH of the system stabilizes, washing the filtered filter cake with water, and collecting a third filtrate and a third filter cake, wherein the third filtrate is a low-concentration inositol solution;

[0035] (4) drying the third filter cake obtained in step (3) at high temperature and then calcining it to obtain 165.3 g of solid tricalcium phosphate;

[0036] (5) The low-concentration inositol solution obtained in step (3) is concentrated, crystallized, decolorized, and refined to obtain inositol. After testing, the inositol yield reaches 96%-97%.

[0037] In summary, after the above process, the by-products obtained include about 35wt% of dibasic calcium phosphate dihydrate and about 65wt% of tricalcium phosphate.

[0038] Example 3

[0039] (1) adding 1000 g of phytin and 1 L of water into a hydrolysis kettle, and performing hydrolysis at 170° C. and 0.8 MPa for 10 h. After the hydrolysis is completed, the hydrolyzate obtained is filtered to collect the first filtrate and the first filter cake;

[0040] (2) pumping the first filtrate obtained in step (1) into a neutralization tank, adding lime and water in a mass ratio of 1:2.5 to the neutralization tank while stirring to adjust the pH of the first filtrate to 6.2, filtering after the pH of the system is stable, compacting the filter cake as much as possible and draining it, washing the filter cake with 50-60° C. water, collecting the second filtrate and the second filter cake, crushing the second filter cake and drying it in a low-temperature oven at 65° C. to obtain 79.6 g of dihydrated calcium hydrogen phosphate as a by-product;

[0041] (3) mixing the first filter cake of step (1) and the second filtrate obtained in step (2), then adding lime milk obtained by mixing lime and water in a mass ratio of 1:2.5 to adjust the pH of the system to 10.0, stirring, filtering after the pH of the system stabilizes, washing the filtered filter cake with water, and collecting a third filtrate and a third filter cake, wherein the third filtrate is a low-concentration inositol solution;

[0042] (4) drying the third filter cake obtained in step (3) at high temperature and then calcining it to obtain 146.9 g of solid tricalcium phosphate;

[0043] (5) The low-concentration inositol solution obtained in step (3) is concentrated, crystallized, decolorized, and refined to obtain inositol, and the yield of inositol reaches 96-97%.

[0044] In summary, after the above process, the by-products obtained contain about 35 wt% of dibasic calcium phosphate dihydrate and about 65 wt% of tricalcium phosphate.

[0045] Comparative Example

[0046] (1) adding 1000 g of phytin and 1 L of water into a hydrolysis kettle, and performing hydrolysis at 170° C. and 0.8 MPa for 10 h. After the hydrolysis is completed, the hydrolyzate obtained is filtered to collect the first filtrate and the first filter cake;

[0047] (2) pumping the first filtrate obtained in step (1) into a neutralization tank, adding lime and water in a mass ratio of 1:2.5 to the neutralization tank while stirring to adjust the pH of the first filtrate to 10.0, stirring, filtering after the pH of the system stabilizes, washing the filtered filter cake with water, collecting the second filtrate and the second filter cake, the second filtrate is a low-concentration inositol solution;

[0048] (4) drying the second filter cake obtained in step (3) at high temperature and then calcining it to obtain 210 g of solid tricalcium phosphate;

[0049] (5) The low-concentration inositol solution obtained in step (3) is concentrated, crystallized, decolorized, and refined to obtain inositol, with an inositol yield of 96-97%.

[0050] In summary, after the above process, the by-products obtained are all tricalcium phosphate.

[0051] In summary, the present invention effectively optimizes the treatment method of the phytin hydrolyzate, obtains two by-products, namely, dibasic calcium phosphate dihydrate and tricalcium phosphate, and has a high yield of the by-products and high economic value. It also greatly reduces the subsequent calcination amount of tricalcium phosphate, thereby reducing the emission of pollutant gases, is more environmentally friendly, and achieves the purpose of energy saving and emission reduction.

[0052] 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. A method for treating a phytin hydrolyzate, characterized in that: The following steps are involved: (1) filtering the phytin hydrolyzate to collect a first filtrate and a first filter cake; the phytin hydrolyzate is prepared by mixing phytin and water to obtain phytin slurry, and then pumping the phytin slurry into a hydrolysis tank to hydrolyze at a temperature of 160-180° C. and a pressure of 0.6-1.0 MPa; (2) pumping the first filtrate into a neutralization tank, adding lime milk to the neutralization tank to adjust the pH of the first filtrate, stirring and filtering, washing the filter cake with water during filtration, collecting the second filtrate and the second filter cake, and drying the second filter cake to obtain a by-product of calcium hydrogen phosphate dihydrate; when adding the lime milk, the system temperature is maintained below 65° C.; adding the lime milk to adjust the pH of the first filtrate to 6.0-6.5; (3) mixing the first filter cake obtained in step (1) and the second filtrate obtained in step (2), then adding lime milk to adjust the pH of the system to 9-11, stirring and filtering, washing the filter cake with water during filtration, collecting a third filtrate and a third filter cake, wherein the third filtrate is an inositol solution; (4) drying the third filter cake obtained in step (3) and then calcining it to obtain solid tricalcium phosphate; (5) The inositol solution obtained in step (3) is concentrated, crystallized, decolorized and refined to obtain inositol.

2. The method for treating a phytin hydrolyzate according to claim 1, wherein: The mass ratio of Phytin to water is 1:(1-2).

3. The method for treating a phytin hydrolyzate according to claim 1, characterized in that: The hydrolysis time is 9-11h.

4. The method for treating a phytin hydrolyzate according to claim 1, characterized in that: In step (2) and step (3), the lime milk is prepared by mixing lime and water in a mass ratio of 1:(2-3).

5. The method for treating a phytin hydrolyzate according to claim 1, characterized in that: In step (2), the temperature of the washing water when the second filter cake is washed with water is 50-60°C.