The traditional production method of inositol is pressure hydrolysis. Due to years of industrial production experience, the pressure hydrolysis method is the main process technology adopted by domestic manufacturers and has been continuously improved in production. The general process of pressure hydrolysis method is as follows: phytin (hydrolysis) → hydrolysis solution (neutralization, filtration) → inositol solution (impurity removal and concentration, crystallization centrifugation) → crude inositol (dissolution and impurity removal, crystallization centrifugation) → fine product. Among them, hydrolysis and refining are the two key steps.
Sodium phytate hydrolysis
Using corn soaked water as raw material, sodium phytate is produced by ion exchange resin adsorption method, and then subjected to pressure hydrolysis reaction to produce inositol. At the same time as producing inositol, the co production of disodium hydrogen phosphate (the production of disodium hydrogen phosphate is about 12 times that of inositol) effectively recovers organic phosphorus from grains, opening up a new path for the recovery of organic phosphorus in agricultural and sideline products.
Production process description: Corn soaking water is adsorbed by ion exchange resin to obtain a certain concentration of sodium phytate solution, which is subjected to pressure hydrolysis reaction to generate inositol and disodium hydrogen phosphate. After a certain reaction time, the material is discharged, filtered, cooled, and crystallized, resulting in the precipitation of disodium hydrogen phosphate crystals. The hydrolysis reaction solution of sodium dihydrogen phosphate crystals is sequentially refined through anion and cation exchange resins until the concentration of anions and cations in the hydrolysis reaction solution reaches the specified standard. The refined hydrolysis reaction solution can be concentrated and crystallized to obtain the finished product inositol. The yield of inositol is mainly affected by three factors: hydrolysis reaction time, hydrolysis reaction pressure, and concentration of sodium phytate solution. Through orthogonal experiments, the optimal reaction conditions for hydrolysis reaction were obtained as follows: hydrolysis time of 7-8 hours, concentration of sodium phytate of 20%, hydrolysis pressure of 1.5 MPa, and average yield of inositol ranging from 0.1544% to 0.1722%. In order to observe the amplification effect of hydrolysis reactor, bed blockage in industrial ion exchange tower, changes in exchange capacity, and simulate the large circulation operation conditions used in the regeneration stage of industrial equipment, a pilot test was conducted on a device with a processing capacity of 600m/a under the above reaction conditions. The average yield of inositol is 0.1601% (more than 2.5 times higher than the calcium phytate method, and the product quality meets the various indicators specified in the National Pharmacopoeia), which is consistent with the small-scale test data.
Atmospheric pressure catalytic method
The atmospheric pressure catalytic method is a new method for producing inositol that has been newly developed and put into industrial production in China in recent years. Its hydrolysis and refining have unique characteristics. Significant features:
(1) Significantly reduces the one-time investment in equipment, and can save more than 50% of equipment investment when the scale is the same;
(2) The use of phytin hydrolysis catalyst shortens the production cycle and improves the utilization rate of raw materials;
(3) The refining process has been improved, resulting in an increase in product quality and yield.
Atmospheric pressure catalytic process: A certain proportion of catalyst (composed of glycerol, urea, and calcium carbonate) is added to a certain concentration of phytin solution at atmospheric pressure, and heated for hydrolysis. After hydrolysis, filtration, crystallization, drying, and other processes, inositol can be obtained. Due to the inherent characteristics of the catalyst, inositol can be crystallized in one go, resulting in higher quality finished products and simplifying the process. Catalysts can be recycled.