A system and method for pretreatment and upgrading of high-sodium and high-calcium coal in oxygen/carbon dioxide combustion

Abstract

The invention provides a pretreatment upgrading system and method of high-sodium and high-calcium coal during combustion of oxygen / carbon dioxide. The system comprises an oxygen / carbon dioxide combustion power generation system and the like. Through heat exchange between smoke and low-temperature nitrogen and low-temperature oxygen, utilization of cold energy is achieved. By introducing part of collected CO2 into a carbonic acid / pulverized coal acid treatment reaction chamber, an acid environment is manufactured, and accordingly sodium and calcium are removed. According to the method, cold energy obtained from the air separation process can be collected and utilized, gradient utilization of cold-heat energy is achieved, and CO2 generated during oxygen / carbon dioxide combustion is sufficiently utilized. By controlling temperature and pressure in the carbonic acid / pulverized coal acid treatment reaction chamber, the sodium element in the high-sodium and high-calcium coal and the calcium element which cannot be removed easily through a traditional washing method can be removed efficiently, and sodium removal, calcium removal and drying treatment of the high-sodium and high-calcium coal are achieved. By the adoption of the pretreatment upgrading system and method, the problem that in the oxygen / carbon dioxide combustion process, the high-sodium and high-calcium coal is quite prone to ash deposition, slagging and other heat exchange surface contamination situations can be effectively relieved.

Description

Technical field: [0001] The invention belongs to the field of coal-fired thermal power generation systems, and in particular relates to a pretreatment system and method for high-sodium and high-calcium coal in oxygen / carbon dioxide combustion. Background technique: [0002] With the continuous and rapid development of my country's industrial level, the demand for electricity is increasing day by day, and the problem of energy shortage in my country is becoming more and more serious. And at present and in the foreseeable future, my country's energy structure will be dominated by coal for a long time. The coalfields discovered in the eastern part of Jungar in Xinjiang are predicted to contain 390 billion tons of coal resources, which can alleviate the shortage of coal resources in my country to a certain extent. The Zhundong coalfield is the largest integrated coalfield discovered so far in my country and even in the world. Based on the current annual coal consumption in my ...

AI Technical Summary

Problems solved by technology

However, it is difficult to effectively remove calcium contained in Zhundong coal by washing with water, and the calcium oxide produced by combustion is also an important factor affecting ash deposition and slagging, so other methods must be found to remove calcium in coal powder

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