| 摘要 |
PURPOSE: A semi-dry type preparation method of starch acetate is provided, to prevent the use of excess amount of solvents and water, thereby reducing loss percentage of products and improving productivity. CONSTITUTION: The method comprises the steps of (S1) injecting starch into a reactor and pre-drying it at a temperature of 30-80 deg.C to make the water content of starch be 5-12 wt%; (S2) spray-injecting 3-10 wt% of liquid acetic esterification agent to 90-97 wt% of predried starch with stirring; (S3) spray-injecting a sodium carbonate aqueous solution to the mixture to make pH be 8.5-9.0 with stirring; (S4) esterifying the obtained mixture at a temperature of 60-80 deg.C for 2-4 hours; (S5) injecting 40-60 wt% of the obtained product and 40-60 wt% of an alcohol aqueous solution into a refining apparatus, neutralizing it to pH 6.0-8.0 with diluted HCl or H2SO4, and refining it; and (S6) dehydrating and drying the refined one.
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