Regeneration method for inactivated TiV-based honeycomb denitration catalyst having combined denitration and demercuration modification function

Abstract

The invention discloses a regeneration method for an inactivated TiV-based honeycomb denitration catalyst having the combined denitration and demercuration modification function. Firstly, the physical and chemical properties of an SCR denitration catalyst are detected, and the inactivated reasons of the catalyst are analyzed. Secondly, the regenerable catalyst is subjected to ultrasonic cleaning in deionized water, a strong alkaline solution or a strong acid solution, so that deposited ashes and pernicious elements in the catalyst can be removed. Thirdly, the cleaned catalyst is immersed in a combined denitration and demercuration regeneration solution, until the activity of the catalyst is stable. Finally, the activated catalyst is transferred to a microwave oven to be dried and calcined through the microwave heating process. The catalyst, obtained through the above method, successively has the combined oxidation and demercuration capacity, while the denitration activity of the catalyst is recovered at the same time. At a temperature smaller than 350 DEG C, the denitration efficiency of the catalyst is up to be equal to or over 90%, and the demercuration efficiency of the catalyst is up to be equal to or over 90%. Meanwhile, the condition that the cost is increased due to the demercuration process after the flue gas denitrification process can be avoided. Therefore, the method is economical and environmentally-friendly, thus being suitable for industrial promotion.

Description

technical field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a regeneration method of a deactivated vanadium-titanium-based honeycomb denitrification catalyst combined with denitrification and mercury removal modification. Background technique

[0002] my country's energy consumption is dominated by coal, and electricity production mainly comes from the direct combustion of coal in thermal power plants. Pollutants emitted by thermal power plants include respirable solid particles, carbon dioxide, sulfur dioxide, and nitrogen oxides (NO x )Wait. Nitrogen oxides, as one of the main air pollutants, have attracted widespread attention because they can cause acid rain, light pollution, global warming, and reduce the ozone layer. With the development of the economy, the demand for environmental protection is increasing day by day. my country has continuously strengthened the emission concentration limit of nitrogen oxides...

Examples

Embodiment 1

[0025] In this experiment, a vanadium-titanium-based honeycomb denitrification catalyst deactivated in a power plant was used as the experimental raw material. The cross-sectional size of the catalyst was 150mm×150mm. Small pieces of 30mm×30mm×50mm were cut from the raw material for regeneration. The steps are as follows:

[0026] Step 1: Analyze the cause of catalyst deactivation, the results are as follows:

[0027] (1) After the catalyst has been used for a certain period of time, its denitrification efficiency has dropped significantly, and the decline rate has reached more than 40%, which is determined to be deactivated;

[0028] (2) The surface of the deactivated catalyst is obviously clogged, but the specific surface area and pore volume do not decrease significantly;

[0029] (3) The crystal form of the catalyst changes partially, TiO 2 It still exists in the anatase type with good catalytic activity, but the molding material SiO 2 The crystal structure changes, whic...

Embodiment 2

[0051] Step 1: Cut a 30 mm × 30 mm × 50 mm small piece of deactivated catalyst from the deactivated catalyst raw material of the same power plant in Example 1 for regeneration, put the catalyst into deionized water and ultrasonically clean it for 40 minutes, and remove the dust in the catalyst honeycomb channel .

[0052] Step 2: Put the catalyst after water washing into 0.2% H 2 SO 4 The solution was ultrasonically cleaned for 40 minutes, and the acid-washed catalyst was rinsed with water until pH = 4-6, and stood until no water flowed down.

[0053] Step 3: Immerse the acid-washed catalyst in the combined denitrification and demercuration regeneration solution, the concentration of oxalic acid in the regeneration solution is 0.5wt%, the concentration of ammonium metavanadate is 0.7wt%, the concentration of ammonium metatungstate is 3.5wt%, nitric acid The concentration of cerium is 1wt%, the concentration of copper chloride is 0.1wt%, the immersion time is 30min, and after...

Embodiment 3

[0060] Step 1: Cut a 30 mm × 30 mm × 50 mm small piece of deactivated catalyst from the deactivated catalyst raw material of the same power plant in Example 1 for regeneration, put the catalyst into deionized water and ultrasonically clean it for 40 minutes, and remove the dust in the catalyst honeycomb channel .

[0061] Step 2: Put the catalyst cleaned by water into a NaOH solution with a mass concentration of 0.5% for ultrasonic cleaning for 30 minutes, and then put it into a 0.2% H 2 SO 4 The solution was ultrasonically cleaned for 40 minutes, and the acid-washed catalyst was rinsed with water until pH = 4-6, and stood until no water flowed down.

[0062] Step 3: Immerse the acid-washed catalyst in the combined denitrification and demercuration regeneration solution, the concentration of oxalic acid in the regeneration solution is 0.5wt%, the concentration of ammonium metavanadate is 1wt%, the concentration of ammonium metatungstate is 5wt%, and the concentration of ceriu...

technical field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a regeneration method of a deactivated vanadium-titanium-based honeycomb denitrification catalyst combined with denitrification and mercury removal modification. Background technique

[0002] my country's energy consumption is dominated by coal, and electricity production mainly comes from the direct combustion of coal in thermal power plants. Pollutants emitted by thermal power plants include respirable solid particles, carbon dioxide, sulfur dioxide, and nitrogen oxides (NO x )Wait. Nitrogen oxides, as one of the main air pollutants, have attracted widespread attention because they can cause acid rain, light pollution, global warming, and reduce the ozone layer. With the development of the economy, the demand for environmental protection is increasing day by day. my country has continuously strengthened the emission concentration limit of nitrogen oxides...

Examples

Embodiment 1

[0025] In this experiment, a vanadium-titanium-based honeycomb denitrification catalyst deactivated in a power plant was used as the experimental raw material. The cross-sectional size of the catalyst was 150mm×150mm. Small pieces of 30mm×30mm×50mm were cut from the raw material for regeneration. The steps are as follows:

[0026] Step 1: Analyze the cause of catalyst deactivation, the results are as follows:

[0027] (1) After the catalyst has been used for a certain period of time, its denitrification efficiency has dropped significantly, and the decline rate has reached more than 40%, which is determined to be deactivated;

[0028] (2) The surface of the deactivated catalyst is obviously clogged, but the specific surface area and pore volume do not decrease significantly;

[0029] (3) The crystal form of the catalyst changes partially, TiO 2 It still exists in the anatase type with good catalytic activity, but the molding material SiO 2 The crystal structure changes, whic...

Embodiment 2

[0051] Step 1: Cut a 30 mm × 30 mm × 50 mm small piece of deactivated catalyst from the deactivated catalyst raw material of the same power plant in Example 1 for regeneration, put the catalyst into deionized water and ultrasonically clean it for 40 minutes, and remove the dust in the catalyst honeycomb channel .

[0052] Step 2: Put the catalyst after water washing into 0.2% H 2 SO 4 The solution was ultrasonically cleaned for 40 minutes, and the acid-washed catalyst was rinsed with water until pH = 4-6, and stood until no water flowed down.

[0053] Step 3: Immerse the acid-washed catalyst in the combined denitrification and demercuration regeneration solution, the concentration of oxalic acid in the regeneration solution is 0.5wt%, the concentration of ammonium metavanadate is 0.7wt%, the concentration of ammonium metatungstate is 3.5wt%, nitric acid The concentration of cerium is 1wt%, the concentration of copper chloride is 0.1wt%, the immersion time is 30min, and after...

Embodiment 3

[0060] Step 1: Cut a 30 mm × 30 mm × 50 mm small piece of deactivated catalyst from the deactivated catalyst raw material of the same power plant in Example 1 for regeneration, put the catalyst into deionized water and ultrasonically clean it for 40 minutes, and remove the dust in the catalyst honeycomb channel .

[0061] Step 2: Put the catalyst cleaned by water into a NaOH solution with a mass concentration of 0.5% for ultrasonic cleaning for 30 minutes, and then put it into a 0.2% H 2 SO 4 The solution was ultrasonically cleaned for 40 minutes, and the acid-washed catalyst was rinsed with water until pH = 4-6, and stood until no water flowed down.

[0062] Step 3: Immerse the acid-washed catalyst in the combined denitrification and demercuration regeneration solution, the concentration of oxalic acid in the regeneration solution is 0.5wt%, the concentration of ammonium metavanadate is 1wt%, the concentration of ammonium metatungstate is 5wt%, and the concentration of ceriu...

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