SU1669915A1 - Method for amorphous cellulose preparation - Google Patents

Abstract

The invention relates to the production of modified cellulose used to produce glucose. The invention allows to simplify the process (exclude the use of volatile, toxic flammable substances, as well as heating), which is achieved by dissolving cellulose in an aqueous copper-ammonia solution, precipitating cellulose in the form of a copper-ammonia complex with ethylene glycol or its aqueous solution containing at least 91% diethylene glycol at a volume ratio of precipitator and a solution of 3: 1, followed by decomposition of the complex by treating it with 1 to 5 wt.% - an aqueous solution of sulfuric or maleic acid, washing the selected target product and water and its drying. 1 tab.

Description

The invention relates to the production of modified cellulose used to produce glucose.

The purpose of the invention is to simplify the process.

PRI me R 1. A 25% aqueous ammonia solution, copper hydroxide and sulphate pulp are mixed, containing 97% alpha fraction and having a degree of polymerization of 820. The steps for preparing a copper-ammonia cellulose solution have the following durations: load 0.24 h, dissolving 2.0 h, dilution 1.0 h and thawing 0.5 h.

The resulting solution contains,%: cellulose 10; copper 4; ammonia 6.5. The degree of polymerisation of the polymer is 500.

A copper-ammonium cellulose complex (MACC) is precipitated from a copper-ammonium cellulose solution (MARC) by spinning (OEG) at a volume ratio of DEG: MARC equal to 3: 1. In the form

Fiber sediment MACC mass ratio of Cu: cellulose (C) is 0.44.1. MACC is separated from the mother liquor, dried and treated with a 1% aqueous solution of sulfuric acid at a volume ratio of sediment: solution of acid equal to 1: 3. Processing time 10 min. Regenerated cellulose is washed with water until neutral and dried at room temperature. According to the X-ray diffraction analysis, the obtained cellulose is amorphous. Its density is 1473 kg / m. The amorphous cellulose obtained is hydrolyzed with a glucose yield of 93%.

The yield of the target product is 90%. DEG consumption per 1 kg of amorphous cellulose is 7 kg.

Examples 2-6. Performed analogously to example 1, but with other values of the parameters.

The data presented in the table.

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Claims (1)

The method of obtaining amorphous cellulose, which includes the steps of dissolving cellulose, precipitating, washing and drying the target product, characterized in that, in order to simplify the process, cellulose is dissolved in an aqueous ammonia copper solution, the precipitation is carried out with diethylene glycol or its aqueous solution contains dosing at least 91% by weight of diethylene glycol, with a precipitator-solution with a volume ratio of 3: 1 with the release of cellulose in the form of its copper-ammonia complex, drying and subsequent decomposition of the complex by treating it with 1-5% by weight aqueous solution of sulfuric or maleic acid and washing the selected target product with water.