Novel method for preparing silicon dioxide and active carbon from rice hull ash

Abstract

The invention discloses a novel method for preparing silicon dioxide and active carbon from rice hull ash, in particular relatives to a novel method for preparing silicon dioxide and active carbon from rice hull ash obtained through thermal decomposition of rice hulls. Major raw materials of sodium carbonate react with the rice hull ash after high-temperature decomposition to generate sodium silicate solid, and a soluble glass solution and solid active carbon are obtained after water dissolution, so the one-step completion of the silicon dissolution and activation is realized. The soluble glass solution is carbonized for separating out the silicon dioxide, a sodium carbonate solution is obtained through filtration, and sodium carbonate solid is obtained through crystallization. In the whole preparation process, the sodium carbonate only performs the effect of a catalyst, so sodium carbonate has no consumption, can be in cyclic utilization, reduces the cost, and reduces the waste water discharge. In the silicon dissolution stage, carbon dioxide gas generated by the decomposition of the sodium carbonate is fixed with burning tail gas of the rice hulls to be used as precipitating agents for preparing the silicon dioxide through purification treatment, so the cost is reduced, the greenhouse gas discharge is reduced, and the cyclic utilization of the carbon dioxide is realized.

Description

technical field [0001] The invention relates to a new method for preparing silicon dioxide and activated carbon from rice husk ash, in particular to a new method for recycling carbon dioxide and sodium carbonate in the process of synchronously dissolving and activating silicon dioxide and activated carbon by using rice husk ash as a raw material. Background technique [0002] Today, with the rapid development of industrialization, human beings are facing the pressure of rapid environmental degradation. Among them, the rise in global temperature caused by the greenhouse effect is one of the most important problems to be solved. In order to cope with global climate change, governments of various countries will adopt economic means, environmental protection means, legal means and even necessary administrative means to limit the development of high energy consumption and high pollution industries. my country's "Action Goal for Controlling Greenhouse Gas Emissions" is: by 2020, ...

AI Technical Summary

Problems solved by technology

[0005] Among the above patents, some patents use the silicon source in rice husk ash to prepare water glass and silicon dioxide separately; some patents use the carbon source in rice husk ash to prepare activated carbon separately, and the rice husk ash is not fully utilized.

There are also some patents that first separate carbon and silica, and then activate carbon at high temperature to prepare activated carbon, which makes the cost of the reaction too high

And most of the patents do not take into account the pollution of the waste liquid and waste gas generated in the production process to the environment