Method for coproducing xylose, white carbon black and active carbon from rice hulls

Abstract

A method for coproducing xylose, white carbon black and active carbon from rice hulls comprises the following steps that: the rice hulls are washed and boiled by water, and the xylose is hydrolyzed by diluted acid; low-temperature carbonization is carried out, then, reaction with concentrated alkaline is taken to extract silicon dioxide, and the white carbon black is prepared by a coprecipitation method; and solid is added into liquor zinci chloride to be soaked for a certain time at a low temperature, then, high-temperature activation and acid washing are carried out, the materials are washed by water to the neutral state, and the materials are dried and ground to obtain active carbon. In the method provided by the invention, one line is adopted for coproducing the xylose, the white carbon black and the active carbon with high specific surface area in a branch way, the xylose preparation process for continuously hydrolyzing the hemicellulose in the rice hulls is adopted for the xylose, the xylose yield is improved, the method belongs to a simple and feasible xylose preparation process, the white carbon black is prepared by adopting an advanced chemical coprecipitation method, higher dispersing degree of the precipitation particles is maintained through adding surfactants into a solution system, and high-purity and ball-shaped white carbon black particles are prepared. The active carbon is activated by adopting the chemical activation method, the activation temperature is low, micro carbon crystals with small dimension can be favorably formed, and the active carbon with more developed porosity and better absorption performance can be obtained. The method provided by the invention has the advantages that the integrated and sufficient utilization of the rice hulls is realized, the maximum use of raw materials is realized, the integrated investment is low, the process technology is simple, and the industrialized production is easy to realize.

Description

technical field [0001] The invention relates to a method for preparing chemical products, in particular to a method for co-producing xylose, white carbon black and activated carbon with rice husks. Background technique [0002] As a base material of health food, xylose is widely used as a non-calorie sugar to meet the needs of obese and diabetic patients who love sweets due to the increasing demand for health food. In food, beverage and infusion. At present, the preparation methods of xylose mainly include neutralization deacidification process and ion exchange deacidification process. In addition, the xylose preparation process also includes electrodialysis deacidification method and chromatographic separation method. The neutralization deacidification process and the ion exchange deacidification process are two relatively mature production processes in China, and the ion exchange deacidification process has a relatively neutral industrial position because it better solve...

AI Technical Summary

Problems solved by technology

Among the current methods for preparing nano-silica, gas phase method, co-precipitation method, sol-gel method and microemulsion method all have certain shortcomings: such as the gas phase method is expensive to produce and has high technical requirements; the traditional precipitation method controls the process. It is complex and prone to hard agglomeration, and it is difficult to obtain high-quality products with stable performance; the sol-gel method has many parameters for controlling sol-gelation, and the parameters are high and difficult to grasp, and the post-processing of the product The process has special requirements; the microemulsion method is affected by many factors, the particle size of the product is not easy to control, and it is difficult to obtain ultrafine particles with small and uniform particle size

The preparation of activated carbon by the above method has a lot of equipment and relatively complicated process technology; high requirements and difficult to grasp; high cost, large energy consumption, and large pollution.