Method for reducing NO by using iron catalyst

Abstract

The invention relates to a method for reducing NO by using an iron catalyst, comprising the following step of: enabling the gas NO generated in a coal burning process to be in contact with metallic iron at a temperature of 500-1100 DEG C. The invention has the advantages of simpleness, low cost and high efficiency without secondary pollution and can achieve the NO removal efficiency more than 95 percent at more than 750 DEG C.

Description

technical field

[0001] The invention belongs to the technical field of NO treatment of industrial coal-fired boiler polluted gas, and in particular relates to a method for reducing NO with an iron catalyst. Background technique

[0002] Coal is the main primary energy in my country, accounting for about 70% of the total primary energy consumption in my country. During the combustion and utilization of coal, the nitrogen oxide (NO) pollutant gas emitted is the main source of pollutants that cause air pollution in major industrial areas in my country. NO pollutants cause acid rain, forest destruction, soil compaction and acidification, and a series of related ecological and environmental problems, and pose a direct threat to human health. It is very important to effectively control the NO gas emission in the coal combustion process.

[0003] The control technology of NO includes the control of the combustion process and the control after combustion. The control technology o...

Examples

Embodiment 1

[0023] Under the following conditions: use high-purity nitrogen (N 2 ) is the trim gas, NO gas with a volume percentage of 10% (N 2 As the balance gas) is the NO gas source, they are evenly mixed and metered by the rotameter to form the simulated flue gas, the flow rate of the simulated flue gas is 1.5L / min, and the volume percentage of NO in the flue gas is 0.05%. The above-mentioned simulated flue gas is passed into a horizontally arranged ceramic tube with an inner diameter of 2.9cm. The ceramic tube is placed horizontally in an electric heating furnace for heating. The length of the heating section is 30cm. The heating temperature is controlled by a program, and the temperature range is 300-1100°C . Use barbed wire as a catalyst, and the specifications of the barbed wire are: the size of a single grid is 6×6mm, and the diameter of the wire is 0.5mm. The barbed wire mesh is a rectangular mesh with length×width=(80~160)×(40~120)mm, which is rolled into a roll along its sho...

Embodiment 2

[0026] Under the following conditions: the flue gas flow rate is 1.5L / min, the volume percentage of NO in the flue gas is 0.04%-0.1%, and the temperature range is 300-1100°C. Use barbed wire as a catalyst, and the specifications of the barbed wire are: the size of a single grid is 6×6mm, and the diameter of the wire is 0.5mm. The barbed wire is a rectangular net with length × width = 160 × 80mm, rolled into a roll along its short side.

[0027] figure 2 for the experimental results. The results show that when the temperature exceeds 700°C, the flue gas contains different volume percentages of NO, and the removal rate can reach more than 90%.

Embodiment 3

[0029] Under the following conditions: the flue gas flow rate is 1.5L / min, the volume percentage of NO in the flue gas is 0.05%, and the temperature range is 300-1100°C. Use barbed wire as a catalyst, and the specifications of the barbed wire are: the size of a single grid is 6×6mm, and the diameter of the wire is 0.5mm. The barbed wire is a rectangular net with length × width = 160 × 80mm, rolled into a roll along its short side. Add 0.05%-0.1% CO in the flue gas by volume.

[0030] image 3 for the experimental results. The experimental results show that with the increase of reaction temperature, the removal efficiency of NO under the action of iron and CO increases gradually. When the volume percentage of CO is 0.1%, NO is almost completely removed after the temperature exceeds 800 °C. When the volume percentage of CO is 0.05%, NO is almost completely removed when the temperature exceeds 950 °C.

[0031] The comparison found that the amount of barbed wire had a signifi...

technical field

[0001] The invention belongs to the technical field of NO treatment of industrial coal-fired boiler polluted gas, and in particular relates to a method for reducing NO with an iron catalyst. Background technique

[0002] Coal is the main primary energy in my country, accounting for about 70% of the total primary energy consumption in my country. During the combustion and utilization of coal, the nitrogen oxide (NO) pollutant gas emitted is the main source of pollutants that cause air pollution in major industrial areas in my country. NO pollutants cause acid rain, forest destruction, soil compaction and acidification, and a series of related ecological and environmental problems, and pose a direct threat to human health. It is very important to effectively control the NO gas emission in the coal combustion process.

[0003] The control technology of NO includes the control of the combustion process and the control after combustion. The control technology o...

Examples

Embodiment 1

[0023] Under the following conditions: use high-purity nitrogen (N 2 ) is the trim gas, NO gas with a volume percentage of 10% (N 2 As the balance gas) is the NO gas source, they are evenly mixed and metered by the rotameter to form the simulated flue gas, the flow rate of the simulated flue gas is 1.5L / min, and the volume percentage of NO in the flue gas is 0.05%. The above-mentioned simulated flue gas is passed into a horizontally arranged ceramic tube with an inner diameter of 2.9cm. The ceramic tube is placed horizontally in an electric heating furnace for heating. The length of the heating section is 30cm. The heating temperature is controlled by a program, and the temperature range is 300-1100°C . Use barbed wire as a catalyst, and the specifications of the barbed wire are: the size of a single grid is 6×6mm, and the diameter of the wire is 0.5mm. The barbed wire mesh is a rectangular mesh with length×width=(80~160)×(40~120)mm, which is rolled into a roll along its sho...

Embodiment 2

[0026] Under the following conditions: the flue gas flow rate is 1.5L / min, the volume percentage of NO in the flue gas is 0.04%-0.1%, and the temperature range is 300-1100°C. Use barbed wire as a catalyst, and the specifications of the barbed wire are: the size of a single grid is 6×6mm, and the diameter of the wire is 0.5mm. The barbed wire is a rectangular net with length × width = 160 × 80mm, rolled into a roll along its short side.

[0027] figure 2 for the experimental results. The results show that when the temperature exceeds 700°C, the flue gas contains different volume percentages of NO, and the removal rate can reach more than 90%.

Embodiment 3

[0029] Under the following conditions: the flue gas flow rate is 1.5L / min, the volume percentage of NO in the flue gas is 0.05%, and the temperature range is 300-1100°C. Use barbed wire as a catalyst, and the specifications of the barbed wire are: the size of a single grid is 6×6mm, and the diameter of the wire is 0.5mm. The barbed wire is a rectangular net with length × width = 160 × 80mm, rolled into a roll along its short side. Add 0.05%-0.1% CO in the flue gas by volume.

[0030] image 3 for the experimental results. The experimental results show that with the increase of reaction temperature, the removal efficiency of NO under the action of iron and CO increases gradually. When the volume percentage of CO is 0.1%, NO is almost completely removed after the temperature exceeds 800 °C. When the volume percentage of CO is 0.05%, NO is almost completely removed when the temperature exceeds 950 °C.

[0031] The comparison found that the amount of barbed wire had a signifi...

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