Lignite low nitrogen oxide combustion method with dry-type amino reductive delivery

Abstract

The invention provides a combustion method for brown coal with less nitrogen oxide by dry-type transportation of an amino group reducer and relates to the combustion method for brown coal. The method solves the problems that slag bonding is easy to appear in the boiler combustion of the brown coal by adopting air fractional combustion technology, a catalyst is needed, system investment is huge and operating cost is high in the boiler combustion of the brown coal by adopting selective catalytic reduction technology and denitration efficiency is low and thermal efficiency of the boiler is affected by evaporation of reducer solution in the boiler combustion of the brown coal by adopting selective non-catalytic reduction technology. A boiler with the furnace being divided into a primary combustion zone (1) and a burnout zone (2) from bottom to top is adopted in the boiler combustion method and amino group reducer particles and solution are sprayed grade by grade during the combustion process of the brown coal. By the two methods of the invention, the discharge of the nitrogen oxide can be reduced by more than 60% and the combustion efficiency of the brown coal is up to more than 98%. By the two methods, no slag bonding appears during the combustion of the brown coal, no catalyst is needed and the operating cost is only around 30% of the operating cost of the SCR method. The effect of the method on the thermal efficiency of the boiler is less than 0.5%.

Description

technical field [0001] The present invention relates to a method of burning lignite. Background technique [0002] Nitrogen oxides (NO X ) is one of the main air pollutants emitted by coal-fired boilers. In addition to forming acid rain and destroying the ecological environment, nitrogen oxides can also form photochemical smog, which directly endangers human health. At present, nitrogen oxides have become an air pollutant second only to sulfur dioxide in my country, and their impact on acid rain, air quality and ground ozone concentration is increasing. On January 1, 2004, the new "Emission Standard of Air Pollutants for Thermal Power Plants" (GB13223-2003) was implemented, which is more stringent than the previous standard. Since July 1, 2004, the state has charged 0.6 yuan per pollution equivalent of nitrogen oxides (0.95 kilograms of nitrogen oxides) directly to the unit that emits pollutants. Therefore, it is necessary to reduce nitrogen while ensuring coal combustion ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that slagging easily occurs in boilers currently using air-staged combustion of lignite, the use of selective catalytic reduction technology to burn lignite requires catalysts, huge system investment, and high operating costs, and the use of selective non-catalytic reduction technology has low denitrification efficiency , and the reductant is sprayed into the furnace in the form of a solution, which affects the thermal efficiency of the boiler, and provides a lignite low-NOx combustion method for dry delivery of the amino reductant

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