CHITOSAN PREPARATION PROCESS Russian patent published in 2006 - IPC C08B37/08 

FIELD: natural compounds technology.

SUBSTANCE: chitosan preparation process comprises breaking naturally occurring chitin-containing material, charging it into reactor, demineralization with 6-7% aqueous hydrochloric acid, deproteination with sodium hydroxide solution at 85-95°C, deacetylation with sodium hydroxide solution on heating, decoloration, and washing with water after each stage to pH 6.5. Process is characterized by that chitin-containing material broken to achieve fraction 0.5-6 mm is fed simultaneously into a number of reactors, wherein demineralization is effected with aqueous hydrochloric acid stream at 85-95°C for 1.5 h while controlling pH in each reactor exit to achieve acid concentration in each reactor exit the same as concentration of the initial acid by way of feeding it in a continuous manner. In addition, deproteination is carried out with 6-7% sodium hydroxide solution stream for 1.5 h followed by discharging treated material into autoclave to perform deacetylation simultaneously with decoloration using 50% sodium hydroxide solution at 130-140°C in inert gas environment and in presence of 3-5% hydrogen peroxide solution used in amount 3-5% of the total volume of mixture.

EFFECT: enhanced process efficiency.

1 dwg