Paddy hull burned gas and waste residue comprehensive utilization method

Abstract

The invention discloses a comprehensive utilization method for rice hull combustion emissions and waste residue, in particular a method for preparing superfine silicon dioxide and active carbon with high specific surface area by using the emissions and waste residue generated by the pyrolysis and combustion of the rice hull, which comprises the following steps: the main raw material sodium carbonate (or potassium carbonate) is heated and hydrolyzed to be sodium bicarbonate (or potassium bicarbonate), OH<-> is released, the silicon dioxide in the rice hull ashes is dissolved, the sodium bicarbonate (or the potassium bicarbonate) is reduced to sodium carbonate (or potassium carbonate) after temperature reduction, and then the silicon dioxide precipitate is separated out. The method has the advantages that the silicon dioxide which only plays the role of catalyst in the process can be used circularly without consumption, the cost is reduced; the purified combusted tail gas can be used for preparing a precipitator of the silicon dioxide, thus avoiding the pollution brought by acid neutralization and precipitation in the traditional technology, reducing the cost, making full use of carbon dioxide and reducing green house gas emission; and the activating agent for preparing the active carbon can be recovered, which can be returned to the hydrolyzation process to be reused after adjusting the concentration of the sodium carbonate (or the potassium carbonate), thus reducing the cost.

Description

technical field [0001] The invention relates to a new method for comprehensive utilization of rice husk combustion exhaust gas and waste residue, in particular to a method of using rice husk to produce high-purity rice husk ash obtained through direct combustion for heat supply or pyrolysis for power generation. New approach to nano-silica and ultra-high surface area activated carbon. Background technique [0002] With the rapid development of global industrialization, the consumption of disposable energy continues to increase, causing energy depletion and environmental pollution. The negative impact of these problems is increasing. Human beings are constantly looking for new energy for their own survival and development. , to reduce and replace the consumption of primary energy. Among all kinds of renewable energy, biomass is the only renewable carbon source for storing solar energy, and it is an important part of sustainable renewable energy. The research and development...

AI Technical Summary

Problems solved by technology

[0003] However, there are three problems in the promotion and application of the project: one is that the utilization rate of combustion heat is low, the cost is high, and it is not economical; the other is that the combustion produces a lot of tar, which not only wastes resources but also pollutes the environment; Damage equipment and pollute the environment

[0007] Among the above patents, some patents use rice husk ash to prepare water glass and silica, use the silicon source in rice husk ash, and some patents use rice husk ash to prepare activated carbon, but none of them make full use of rice husk ash; some patents use rice husk ash While preparing silica from ash, activated carbon is also co-produced, and the quality and performance of the obtained silica and activated carbon are both low

Moreover, most patents use sodium hydroxide to dissolve silica in rice husk ash and activate activated carbon, resulting in high cost and no industrial development value.