Ozone oxidation and denitration method of boiler flue gas

Abstract

The invention provides a method for processing de-nitration on the boiler smoke, belonging to the environmental protective technique. The method comprises: ejecting ozone O3 into the low-temperature section of smoke channel of boiler whose temperature ranges from 110-150Deg. C; oxygenizing the nitric oxide NO into high-state nitrogen oxide as NO2, NO3 or N2O5; washing the smoke with alkali liquor to remove the nitrogen oxide in the smoke. Compared to other de-nitration method, said invention has higher efficiency, lower cost, and non-secondary pollution, while the absorption effect combined with alkali liquor can reach more than 80%. In addition, the invention can apply variable boiler devices, which is not relative to the burning condition of boiler.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a boiler flue gas denitrification method, which is suitable for coal-fired and oil-fired boilers and industrial kilns. Background technique [0002] NO produced during energy utilization x is following SO 2 One of the important air pollutants that needs to be treated urgently. In terms of boiler denitrification technology, it can be divided into the following two categories: denitrification during combustion and flue gas denitrification. Denitrification during combustion includes combustion adjustment, air classification, reburning, and low NO x Combustor, OFA and other technologies can achieve good emission reduction effect, but the removal efficiency does not exceed 50%; the relatively mature technologies for flue gas denitrification technology are selective non-catalytic (SNCR) and selective catalytic (SCR) Technology, using amino reducing agents such as amm...

AI Technical Summary

Problems solved by technology

[0002] NO produced during energy utilization x is following SO 2 One of the important air pollutants that needs to be treated urgently. In terms of boiler denitrification technology, it can be divided into the following two categories: denitrification during combustion and flue gas denitrification. Denitrification during combustion includes combustion adjustment, air classification, reburning, and low NO x Combustor, OFA and other technologies can achieve good emission reduction effect, but the removal efficiency does not exceed 50%; the relatively mature technologies for flue gas denitrification technology are selective non-catalytic (SNCR) and selective catalytic (SCR) Technology, using amino reducing agents such as ammonia, ammonia water, urea, etc. to reduce NO x revert to N 2 , SNCR technology is carried out in the temperature range of 800-1200°C, and the denitrification efficiency is about 40-50%; SCR technology is carried out under the condition of 250-600°C catalyst, and the denitrification efficiency can reach 80% or even more than 90%. A denitrification technology with the highest denitrification efficiency in commercial operation, but the investment and operation costs are also very expensive. According to the latest statistics, the initial investment cost is 60-150$ / kW, and the catalyst life is 14,000 ~32,000 hours, and most of the power plants in my country use high-ash coal, and the coal ash content is as high as 20-30%, while in foreign countries it is often only about 10%, which will inevitably lead to a decline in the life of the catalyst, and the cost of the catalyst accounts for about 1 / 3 of the initial investment. It can be seen that its operating cost is also very expensive, and currently only the United States, Germany, Japan and other countries use it.

[0003] With the continuous improvement of environmental protection requirements, the NO x Emission restrictions will also become increasingly strict. If domestic power plants introduce SCR technology on the basis of wet flue gas desulfurization, the investment and operation costs will be unaffordable, and there may be no site layout

Images