阅读说明：本技术 一种新型炉内脱硫、抑氮的技术方法 (Novel in-furnace desulfurization and nitrogen inhibition technical method ) 是由 刘业宽 孙佰平 岳燕 李佃钊 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种新型炉内脱硫、抑氮的技术方法,属于重油生产领域,一种新型炉内脱硫、抑氮的技术方法,包括以下步骤：步骤一：将重油裂化反应产生的烟气导入氧化反应区,臭氧发生器产生的臭氧进入氧化反应区内与烟气中的NOx发生氧化反应生成N-(2)O-(5)；步骤二：将烟气导入脱硫塔内。本发明,通过碱液能够有效的脱除烟气中的SO-(2)、NO、及颗粒物,满足净化烟气排放标准,且能适应上游催化装置负荷变化,具有良好的操作弹性,使用纯水来减少碱液中的钙含量,避免在对烟气进行过滤吸收的过程中产生碳酸钙形成结垢,防止影响循环系统中循环管道的内径,防止堵塞,确保循环碱液的流通顺畅,减少维护成本。(The invention discloses a novel technical method for desulfurization and nitrogen inhibition in a furnace, belonging to the field of heavy oil production, and the novel technical method for desulfurization and nitrogen inhibition in the furnace comprises the following steps: the method comprises the following steps: introducing flue gas generated by heavy oil cracking reaction into an oxidation reaction zone, and allowing ozone generated by an ozone generator to enter the oxidation reaction zone to perform oxidation reaction with NOx in the flue gas to generate N 2 O 5 (ii) a Step two: and introducing the flue gas into a desulfurizing tower. According to the invention, SO in the flue gas can be effectively removed through the alkali liquor 2 NO and particulate matter, meets the emission standard of purified flue gas, and can adapt to the upstreamThe catalytic unit load changes, has good operation elasticity, uses the pure water to reduce the calcium content in the alkali lye, avoids producing calcium carbonate and forms the scale deposit at the in-process that filters the absorption to the flue gas, prevents to influence circulation system mesocycle pipeline's internal diameter, prevents to block up, ensures that circulation alkali lye's circulation is smooth and easy, reduces the maintenance cost.)

1. A novel technical method for desulfurization and nitrogen inhibition in a furnace is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: introducing flue gas generated by heavy oil cracking reaction into an oxidation reaction zone, and allowing ozone generated by an ozone generator to enter the oxidation reaction zone to perform oxidation reaction with NOx in the flue gas to generate N₂O₅；

Step two: introducing flue gas into a desulfurization tower, spraying alkali liquor serving as a desulfurizer and process water into the desulfurization tower through a chilling spray head to form a high-density water curtain, and enabling the flue gas to rise to contact with the water curtain to perform a chemical reaction to absorb sulfur and nitrogen contained in the flue gas;

step three: the absorbed flue gas passes through demisting filler at the top of the desulfurizing tower to filter water vapor and fine particles, and then is discharged to the atmosphere;

step four: then leading the reacted solution into a clarifying tank through a washing tower circulating pump, and then solidifying impurities through a flocculating agent;

step five: and (3) removing impurities precipitated at the bottom of the clarification tank, allowing part of the clear liquid to enter a desulfurizing tower for continuous reaction, and introducing the other part of the clear liquid into an oxidation tank for oxidation and discharging the oxidized clear liquid after reaching the standard.

2. The novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: and the alkali liquor in the step two is prepared by mixing caustic soda and water.

3. The novel technical method for desulfurization and nitrogen suppression in the furnace as claimed in claim 2, characterized in that: the water is distilled water.

4. The novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: and an alkali powder supplementing port and a water supplementing port are arranged on the desulfurizing tower in the second step.

5. The novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: and in the second step, a Venturi tube is fixedly installed on the desulfurizing tower, and the oxidation reaction zone is communicated with the desulfurizing tower through the Venturi tube.

6. The novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: and step two, a honeycomb vent pipe is arranged in the desulfurizing tower, and a spray pipe is arranged at the top of the honeycomb vent pipe.

7. The novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: the reaction equation of the NOx and the ozone in the first step is as follows:

NO+O₃→NO₂+O₂；

2NO₂+O₃→N₅O₂+H₂O。

8. the novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: the main reaction equation of the flue gas and the alkali liquor in the step two is as follows:

SO₂+H₂O→H₂SO₃；

H₂SO₃+NaOH→Na₂SO₃+H₂O；

NaSO₃+H₂SO₃→NaHSO₃；

NaHSO₃+NaOH→2Na₂SO₃+2H₂O；

Na₂SO₃+1/2O₂→Na₂SO₄；

N₅O₂+H₂O→2HNO₃；

HNO₃+NaOH→NaNO₃+H₂O。

9. the novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: the inlet temperature of the flue gas in the step one is between 110 and 150 ℃, and the temperature of the flue gas discharged from the desulfurizing tower in the step three is between 35 and 45 ℃.

10. The novel technical method for desulfurization and nitrogen suppression in the furnace according to claim 1, characterized in that: and the chilling spray heads in the step two are placed in a layered mode, and the number of the chilling spray head layers is at least three.

Technical Field

The invention relates to the field of heavy oil production, in particular to a novel technical method for in-furnace desulfurization and nitrogen inhibition.

Background

The raw oil of the catalytic cracking unit usually contains sulfur-containing compounds such as mercaptan, thioether and thiophene, which are converted into hydrogen sulfide H2S) and thiophene in the catalytic cracking reaction process and exist in oil gas products and coke, the sulfur-containing coke is subjected to oxidation reaction in a regenerator, the generated flue gas pollutes the atmosphere if the sulfur-containing coke is directly discharged, and the nitrogen oxides in the catalytic cracking flue gas mainly come from nitrogen-containing compounds in the catalytic raw material, and effective removal of SO, NO and particulate matters in the catalytic cracking flue gas becomes an important environmental protection subject of the oil refining industry.

When the existing flue gas treatment process is used, the efficiency of desulfurization and denitrification with flue gas is low, and pipeline blockage is often caused when the process is used, the desulfurization and denitrification effect of flue gas treatment is influenced, and harmful substances such as sulfur dioxide discharged by flue gas exceed the standard, so that a novel technical method for in-furnace desulfurization and nitrogen inhibition is provided to solve the problems.

Disclosure of Invention

1. Technical problem to be solved

Aiming at the problems in the prior art, the invention aims to provide a novel technical method for desulfurization and nitrogen inhibition in a furnace, which has the advantages of high desulfurization and denitrification efficiency and low pipeline blockage failure rate, and solves the problems that the desulfurization and denitrification efficiency of flue gas is low, the pipeline is frequently blocked when the novel technical method is used, the desulfurization and denitrification effect of flue gas treatment is influenced, and harmful substances such as sulfur dioxide discharged by the flue gas exceed the standard.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

A novel technical method for desulfurization and nitrogen inhibition in a furnace comprises the following steps:

the method comprises the following steps: cracking heavy oilThe generated flue gas is led into an oxidation reaction zone, and the ozone generated by the ozone generator enters the oxidation reaction zone to be oxidized with NOx in the flue gas to generate N₂O₅；

Step two: introducing flue gas into a desulfurization tower, spraying alkali liquor serving as a desulfurizer and process water into the desulfurization tower through a chilling spray head to form a high-density water curtain, and enabling the flue gas to rise to contact with the water curtain to perform a chemical reaction to absorb sulfur and nitrogen contained in the flue gas;

step three: the absorbed flue gas passes through a demisting filler at the top of the desulfurizing tower to filter water vapor and fine particles;

step four: then leading the reacted solution into a clarifying tank through a washing tower circulating pump, and then solidifying impurities through a flocculating agent;

step five: and (3) removing impurities precipitated at the bottom of the clarification tank, allowing part of the clear liquid to enter a desulfurizing tower for continuous reaction, and introducing the other part of the clear liquid into an oxidation tank for oxidation and discharging the oxidized clear liquid after reaching the standard.

Preferably, the alkali liquor in the second step is prepared by mixing caustic soda and water.

Preferably, the water is distilled water.

Preferably, the desulfurizing tower in the second step is provided with an alkali powder replenishing port and a water replenishing port.

Preferably, a venturi tube is fixedly installed on the desulfurization tower in the second step, and the oxidation reaction zone is communicated with the desulfurization tower through the venturi tube.

Preferably, a honeycomb vent pipe is arranged in the desulfurizing tower in the second step, and a spray pipe is arranged at the top of the honeycomb vent pipe.

Preferably, the reaction equation of the NOx and the ozone in the first step is:

NO+O₃→NO₂+O₂；

2NO₂+O₃→N₅O₂+H₂O。

preferably, the main reaction equation of the flue gas and the alkali liquor in the step two is as follows:

SO₂+H₂O→H₂SO₃；

H₂SO₃+NaOH→Na₂SO₃+H₂O；

NaSO₃+H₂SO₃→NaHSO₃；

NaHSO₃+NaOH→2Na₂SO₃+2H₂O；

Na₂SO₃+1/2O₂→Na₂SO₄；

N₅O₂+H₂O→2HNO₃；

HNO₃+NaOH→NaNO₃+H₂O。

preferably, the inlet temperature of the flue gas in the step one is 110-150 ℃, and the temperature of the flue gas discharged from the desulfurizing tower is 35-45 ℃.

Preferably, the quench nozzles in step two are arranged in layers, and the number of the quench nozzle layers is at least three.

3. Advantageous effects

Compared with the prior art, the invention has the advantages that:

(1) the scheme utilizes a wet flue gas desulfurization technology to desulfurize and remove particles, utilizes a washing liquid treatment system to eliminate the defect of secondary pollution of an absorbent, and can effectively remove SO in flue gas through alkali liquor₂NO and particulate matter, satisfy purification fume emission standard, and can adapt to upstream catalytic unit load change, have good operation elasticity.

(2) The pure water is used for reducing the calcium content in the alkali liquor, calcium carbonate is prevented from forming scale in the process of filtering and absorbing the smoke, the inner diameter of a circulating pipeline in a circulating system is prevented from being influenced, blockage is prevented, the circulation of the circulating alkali liquor is ensured to be smooth, and the maintenance cost is reduced.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1, a novel technical method for desulfurization and nitrogen inhibition in a furnace includes the following steps:

the method comprises the following steps: introducing flue gas generated by heavy oil cracking reaction into an oxidation reaction zone, and allowing ozone generated by an ozone generator to enter the oxidation reaction zone to perform oxidation reaction with NOx in the flue gas to generate N₂O₅Oxidizing NOx contained in the flue gas into N₂O₅So as to be led into the desulfurizing tower for secondary reaction;

step two: introducing flue gas into a desulfurization tower, spraying alkali liquor serving as a desulfurizer and process water into the desulfurization tower through a chilling spray head to form a high-density water curtain, enabling the flue gas to rise to contact with the water curtain to perform chemical reaction, absorbing sulfur and nitrogen contained in the flue gas, performing desulfurization and nitrogen inhibition on the flue gas, purifying the flue gas, and avoiding the pollution of the discharged flue gas to the environment;

step three: the absorbed flue gas passes through a demisting filler at the top of the desulfurizing tower to filter water vapor and fine particles, so that the water vapor and dust carrying trace sulfides and nitrides are prevented from being directly discharged along with the flue gas, and the purifying effect is better;

step four: then leading the reacted solution into a clarifying tank through a circulating pump of a washing tower, solidifying impurities through a flocculating agent, and carrying out solid-liquid separation on the reaction solution so as to recycle the reaction solution;

step five: the impurity that will deposit in the clarification tank bottom gets rid of the processing, and the partial desulfurizing tower that gets into of clear liquid continues the reaction, and the leading-in oxidation jar oxidation of another part is outwards discharged after up to standard, handles waste residue waste liquid innocent treatment, avoids causing the influence to the environment, makes things convenient for the staff to carry out the categorised collection processing simultaneously.

Furthermore, the alkali liquor in the step two is prepared by mixing caustic soda and water, so that the source is wide and the preparation cost is low.

Furthermore, the water is distilled water, the scale formation of the inner wall part of a common washing tower and the scale formation of the inner wall of a pipeline are found through inspection, a scale sample is analyzed, some scales are carried catalyst agglomerates, but the scales on the inner wall of the tower and the inner wall of the pipeline are mainly CaC03, the supplementing water of the flue gas desulfurization washing tower is non-pure water, Ca2+ ions are contained in the water, and the circulating liquid of the washing tower absorbs C02 in the flue gas under the alkaline condition, so that the CaC03 scale formation is reduced, the scale formation of the CaC03 is avoided, the pipeline blockage is avoided, the pipe diameter is reduced, the circulating quantity and the washing effect of the desulfurization tower are influenced, and the content of the Ca2+ ions is reduced by using the pure water, and the formation of the CaC03 is prevented.

Furthermore, the desulfurizing tower in the second step is provided with an alkali powder supplementing port and a water supplementing port, so that loss can exist in the process of circulating alkali liquor, and the alkali liquor can be conveniently supplemented through the alkali powder supplementing port and the water supplementing port.

Furthermore, a venturi tube is fixedly installed on the desulfurizing tower in the second step, the oxidation reaction zone is communicated with the desulfurizing tower through the venturi tube, the application range of the venturi tube is wide, and the blocking phenomenon does not occur after the venturi tube is used for a long time due to general gas, flue gas containing more impurities and the like.

Furthermore, a honeycomb vent pipe is arranged in the desulfurizing tower in the second step, a spray pipe is arranged at the top of the honeycomb vent pipe, when the flue gas rises, the flue gas passes through the honeycomb vent pipe, and then alkali liquor is sprayed through the spray pipe to carry out secondary reaction to absorb and remove SO in the flue gas₂And NO.

Further, the reaction equation of NOx and ozone in the first step is:

NO+O₃→NO₂+O₂；

2NO₂+O₃→N₅O₂+H₂O。

10. further, the main reaction equation of the flue gas and the alkali liquor in the step two is as follows:

SO₂+H₂O→H₂SO₃；

H₂SO₃+NaOH→Na₂SO₃+H₂O；

NaSO₃+H₂SO₃→NaHSO₃；

NaHSO₃+NaOH→2Na₂SO₃+2H₂O；

Na₂SO₃+1/2O₂→Na₂SO₄；

N₅O₂+H₂O→2HNO₃；

HNO₃+NaOH→NaNO₃+H₂O。

further, the flue gas inlet temperature in the step one is 110-150 ℃, the flue gas inlet temperature can be ensured to be suitable for the reaction temperature, the reaction rate is improved, and the temperature of the flue gas discharged from the desulfurizing tower is 35-45 ℃.

Further, the method comprisesAnd step two, the chilling spray heads are placed in a layered mode, and the number of the chilling spray head layers is at least three. The reaction time of the flue gas and the alkali liquor can be prolonged through the multilayer chilling spray heads, and the SO in the flue gas is increased₂And the removal rate of NO.

Ozone generators are well known to those skilled in the art and are well known in the art and will not be described in any greater detail herein.

Utilize wet flue gas desulfurization technique both can desulfurize but also can the desorption particulate matter, utilize washing liquid processing system can eliminate absorbent secondary pollution's drawback, SO2 in can effectual desorption flue gas through alkali lye, NO, and the particulate matter, satisfy and purify flue gas emission standard, and can adapt to upstream catalytic unit load change, good operation elasticity has, reduce the calcium content in the alkali lye through using the pure water, avoid carrying out the filtration absorptive in-process to the flue gas and produce calcium carbonate and form the scale deposit, prevent to influence circulation system well circulation pipeline's internal diameter, prevent to block up, it is smooth and easy to ensure the circulation of circulation alkali lye, reduce the maintenance cost, it is more economic.

The foregoing is only a preferred embodiment of the present invention; the scope of the invention is not limited thereto. Any person skilled in the art should be able to cover the technical scope of the present invention by equivalent or modified solutions and modifications within the technical scope of the present invention.