Method for preparing glucosamine hydrochloride

Abstract

The invention relates to a method for preparing glucosamine hydrochloride, which is characterized by comprising the following steps: 1) treatment of chitin in a gas explosion expanding method: feeding chitin as a raw material into a gas explosion expanding tank, and injecting a gas explosion expanding medium into the gas explosion expanding tank, wherein the gas explosion expanding medium is one of the four substances, namely, steam, water, ammonium hydroxide and ethanol; and instantly releasing the pressure of the gas explosion expanding tank, and discharging the raw material chitin into an atmospheric vessel, thereby obtaining chitin concentrate; 2) hydrolysis with hydrochloric acid; 3) decolorization; 4) filtration; 5) concentration and crystallization; and 6) secondary crystallization. Compared with the prior art, the invention has the following advantages that: 1) the chitin pretreated in the gas explosion expanding method is used as the raw material, and due to the high chemical activity thereof, the invention can achieve a higher product yield; 2) almost no 'coking' can be caused in the process of hydrolysis; 3) the extraction of GAH can be completed at one step during the technological process of technology, thereby simplifying the preparation of GAH; and 4) the hydrochloric acid can be recycled, thereby realizing the clean production of GAH.

Description

technical field [0001] The invention relates to a method for preparing glucosamine hydrochloride, in particular to a method for preparing glucosamine hydrochloride using chitin treated by an air explosion expansion method as a raw material. Background technique [0002] Glucosamine hydrochloride, also known as D-glucosaminehydrochloride (GAH for short), the chemical name is 2-amino-2-deoxy-β-D-glucose hydrochloride, and the chemical formula is C 6 h 14 o 5 NCl, with a relative molecular mass of 215.63, is a white crystalline powder, easily soluble in water but insoluble in ethanol. GAH is a biological agent, which has important physiological significance in the human body: it participates in liver and kidney detoxification, has anti-inflammatory and liver-protecting effects; it can be used to treat rheumatoid arthritis and gastric ulcer disease; if used in conjunction with antibiotics, it can promote antibiotics Absorption in the blood reduces side effects and can inhibit...

AI Technical Summary

Problems solved by technology

Because chitin extracted from shrimp and crab shells has a dense crystal structure, chitin is usually pretreated by crushing and soaking in dilute hydrochloric acid. Even if such a pretreatment method is adopted, it is still difficult to change its dense crystal structure and It is difficult to make it chemically modified. Therefore, the hydrolysis reaction has to adopt higher concentration of hydrochloric acid, higher reaction temperature, and longer reaction time, thus producing a series of disadvantages: 1) while degrading and deacetylating, accelerating 2) Severe "coking" phenomenon occurs, which increases equipment wear; 3) GAH needs to be further extracted from the "mother liquor" after the hydrolysis reaction, which makes the production process more complicated; 4) Hydrochloric acid is difficult to recover , not only wasting raw materials, but also increasing pollutant emissions

Nevertheless, the yield of the traditional preparation GAH process has not exceeded 70%, and there are the above-mentioned shortcomings