A composite additive for coal-fired sulfur-fixing catalytic combustion and its preparation method

Abstract

A composite additive for coal-burning sulfur-fixing catalytic combustion, which is composed of a main sulfur-fixing agent and an auxiliary additive. The main sulfur-fixing agent is composed of dolomite powder and slaked lime, and the auxiliary additive is one of alumina, cerium oxide, iron oxide and quartz sand. or a combination of two or more in arbitrary proportions; its preparation method is: firstly crush dolomite powder and slaked lime to 80-300 mesh respectively and mix them according to the mass percentage, and then mix the selected auxiliary additives uniformly according to the mass percentage to prepare compound additives. The invention has the advantages of: excellent sulfur fixation effect, catalytic combustion performance and coal-saving performance; the product generated by catalytic combustion contains CaO-Al2O3-SiO2 system substances, which can wrap glassy quartz fragments in fly ash, making the original sharp The edges and corners are reduced, which reduces the wear of the fly ash on the pipeline; the preparation method is simple and easy to implement, and can be widely used in coal-fired fields such as industry, civil boilers, casting, and metallurgical power generation.

Description

technical field [0001] The invention relates to coal-fired desulfurization technology, in particular to a coal-fired sulfur-fixing catalytic combustion composite additive and a preparation method thereof. Background technique [0002] my country is one of the largest coal production and consumption countries in the world, and coal accounts for 75% of the total primary energy consumption. With the continuous growth of coal consumption, SO emissions from coal combustion 2 is also increasing, among which SO emissions from coal-fired power plants 2 Accounted for about 40%, and the pattern of coal-based power development will not change in the short term. It is estimated that by 2012, coal-fired power plants SO 2 Emissions will account for the national SO 2 more than 60% of the total emissions. Coal-fired power plant SO 2 The reduction and control of SO emissions has become an important part of our country's future control and reduction of SO emissions. 2 the key of. [0...

AI Technical Summary

Problems solved by technology

However, the current calcium-based sulfur-fixing agents mainly have the following main problems: 1) Ordinary calcium-based sulfur-fixing agents have shortcomings such as low calcium utilization rate and poor sulfur-fixing effect at high temperature. Inconsistent, part or all of the sulfur-fixing agent participates in the combustion process and affects the combustion performance of coal; 2) The volume molar ratio of the sulfate (MSOx) generated by the sulfur-fixing reaction is larger than the volume molar ratio of the basic oxide in the sulfur-fixing agent, and the solid The sulfur reaction can only occur on the surface of the sulfur-fixing agent particles, forming a dense layer of calcium sulfate to cover its surface, and the pore structure of the sulfur-fixing agent is blocked after the high-temperature sintering of the sulfur-fixing agent; 3) The formed sulfate (MSOx) is above 1000 °C Re-decomposition at high temperature, etc., can lead to low sulfur fixation efficiency

However, the addition of some ingredients, especially some minerals, will affect the calorific value of coal, and some ingredients may cause corrosion to the furnace body, increase the emission of other pollutants, and cause secondary pollution