Preparation method and application method of granular activated carbon for xylose decoloring

Abstract

The invention discloses a preparation method and an application method of granular activated carbon for xylose decoloring, which belongs to the field of preparation methods and application methods of activated carbon. The preparation method comprises the following steps: (A) preparing raw materials, namely, weighing phosphoric acid method powder activated carbon made from saw dust, an acrylic emulsion and water according to a ratio of acrylic emulsion to phosphoric acid method powder activated carbon to water being (0.37-0.39):1:1; (B) mixing the raw materials, namely, mixing the weighed raw materials and sufficiently stirring till the granules are uniformly mixed; (C) forming granules, namely, extruding the uniformly mixed raw materials to form granules by using a pelletizing machine at the constant temperature of 90 DEG C, so as to make granules with the particle size of 2-5mm, cooling the granules to be 40-50 DEG C, and drying; (E) separating and cooling. The granular activated carbon prepared by using the method is good in adsorption property, high in strength, acid-alkali resisting, recyclable and reusable, the liquid adsorption amount of unit volume is equivalent to that of other granular activated carbons, and the production environment is improved.

Description

technical field [0001] The invention relates to a method for preparing and using activated carbon, in particular to a method for preparing and using granular activated carbon for xylose decolorization. Background technique [0002] The common production methods of xylitol are chemical method or microbial method, both of which are produced by reducing the hydrolyzate of D-xylose or xylan-rich hemicellulose , and then under high temperature and high pressure, catalytic hydrogenation of pure xylose. In addition to hydrolysis, it is a decolorization and purification process. Therefore, in the production process of xylitol, the decolorization of the hydrolyzate occupies an extremely important position. The large amount of pigments, nitrogen substances, phenolic compounds, furfural and iron in the xylose liquid are mostly macromolecular sugar compounds. At present, there are many manufacturers of granular activated carbon for xylose decolorization. These granular activated carbo...

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Problems solved by technology

At present, there are many manufacturers of granular activated carbon for xylose decolorization. These granular activated carbons are mainly classified into four types according to the production process: one is to directly form coal powder with tar and asphalt, and then activate carbon to obtain coal-based granular activated carbon; Hard shells such as coconut shells or apricot shells are activated by physical carbon to obtain shell activated carbon; the third is to plasticize sawdust and chemicals such as phosphoric acid and then perform carbon activation to obtain wood-shaped activated carbon; the fourth is to use activated carbon with excellent performance In addition, the binder is extruded and then dried to obtain granular activated carbon. In the first two methods, raw materials are in short supply, the production cycle is long, and the production cost is high. Because the carbon is activated by physical methods, it belongs to developed micropores, that is, the pore structure is small, smaller than that of the activated carbon. The molecular diameter of the pigment and impurities in the adsorbed xylose has almost no decolorization ability to macromolecular sugar compounds, so its adsorption ability to xylose is poor, and the effect in the field of xylose decolorization is extremely poor

Because only when the pore structure of activated carbon is slightly larger than the diameter of impurities or harmful gas molecules, the best adsorption effect can be achieved when the impurities or harmful gas molecules can completely enter, and the adsorption effect of activated carbon with too large or too small pore structure is not good. ideal

The phosphoric acid method powder activated carbon produced by the third method has the lightest specific gravity among all activated carbons, the largest specific surface area per unit, well-developed pore size and pore volume, rich molecules with large, medium and small pore sizes, and better decolorization ability than before. The second type, but the strength is not good and the acid and alkali resistance and regeneration are difficult. The activated carbon will be scrapped after one-time use, which will cost a lot. Moreover, when the powdered activated carbon is put in, there will be a lot of dust, the working environment is harsh, and the staff's work intensity is high. The fourth type The method mainly uses physical method to form powdered activated carbon and use it as a handicraft

Moreover, for the above four activated carbons, the plane layers of carbon atoms that make up the activated carbon are disorderly and irregularly arranged into a "helical structure", and they are all combined with each other by intermolecular forces. Therefore, the wear resistance and compressive strength of activated carbon very bad

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