Catalytic cracking tail gas ozone desulfurization and denitrification device
By abolishing the spray cooling facilities in the catalytic cracking exhaust gas desulfurization and denitrification device and installing an ozone distributor in the desulfurization and denitrification tower, the problems of ozone decomposition and corrosion of the spray medium at high temperature are solved, and the integration of desulfurization and denitrification and efficiency improvement are achieved.
Patent Information
- Application Number
- CN202420701276.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-08
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-04-08
AI Technical Summary
The existing catalytic cracking tail gas ozone desulfurization and denitrification equipment is responsible for corrosion caused by ozone decomposition and spraying media under high temperature environments and the problem of liquid level control of desulfurization and denitrification towers, which affects the efficiency of desulfurization and denitrification.
Install an ozone distributor in the desulfurization and denitrification tower, and cancel the spray cooling facilities in front of the ozone distributor. By setting an ozone distributor under the concentration sprayer or between the two layers of concentrated sprayers, desulfurization and denitrification integration is achieved. Eliminate the influence of spray media on the liquid level of exhaust gas pipelines and desulfurization and denitrification tower.
The desulfurization and denitrification efficiency is improved, the completeness of oxidation and absorption reactions is ensured, the corrosion of the spray medium on the equipment is avoided, and the process control in the tower is simplified.
Smart Images
Figure CN222239571U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of industrial waste gas treatment and relates to a catalytic cracking tail gas ozone desulfurization and denitrification device. Background Art
[0002] Ozone denitrification is a major technology for tail gas treatment in catalytic cracking units of petroleum refining industry, and is usually combined with wet desulfurization. Its principle is: using ozone as an oxidant, NO is oxidized into NO2 and higher nitrogen oxides, NO2 and higher nitrogen oxides react with water to form nitric acid and nitrous acid, and the generated nitric acid and nitrous acid react with the desulfurizer in the desulfurization slurry to form nitrates, thereby achieving the purpose of denitrification.
[0003] The main equipment for ozone denitrification is the ozone distributor, which is arranged on the inlet flue of the desulfurization and denitrification tower. Since ozone (O3) is very easy to decompose in an environment above 130°C, but the temperature of the catalytic tail gas is generally above 150°C, it is necessary to arrange a spray cooling facility in front of the ozone distributor. The spray medium is generally desulfurization slurry or process water, which will cause corrosion to the tail gas pipeline. In addition, when process water is used, it will make it difficult to control the liquid level of the desulfurization and denitrification tower. Utility Model Content
[0004] The utility model aims to provide a catalytic cracking tail gas ozone desulfurization and denitration device, which eliminates the influence of spraying medium on the tail gas pipeline and the liquid level of the desulfurization and denitration tower, and realizes the integration of desulfurization and denitration.
[0005] The technical solution of the utility model is: a catalytic cracking tail gas ozone desulfurization and denitration device, comprising a desulfurization and denitration tower, which is provided with an oxidation section, a concentration section, a tail gas inlet, a concentration section spray layer, an oxidation section spray layer, a demister and a flue gas outlet in sequence from bottom to top. The oxidation section spray layer is provided with 2-6 layers of oxidation sprayers, and the oxidation section is connected to the oxidation sprayers through a pipeline. The concentration section spray layer is provided with 2-4 layers of concentration sprayers, and the concentration section is connected to the concentration sprayers through a pipeline. An ozone distributor is provided in the desulfurization and denitration tower, and the ozone distributor is installed between any two layers of oxidation sprayers or concentration sprayers, and the ozone distributor is connected to the ozone storage tank or the ozone generator through an ozone pipeline.
[0006] The oxidation section spray layer is equipped with 3 layers of oxidation sprayers, the concentration section spray layer is equipped with 2 layers of concentration sprayers, and the ozone distributor is installed between the two layers of concentration sprayers. A sleeve wall valve is provided at the connection between the ozone distributor and the ozone pipeline. The ozone pipeline is equipped with an upward U-shaped bend, and an ozone inlet valve is provided at the connection between the ozone pipeline and the U-shaped bend. The demister is a wet electrostatic demister, an S-shaped fiberglass demister or a reinforced polypropylene demister.
[0007] The utility model discloses a catalytic cracking tail gas ozone desulfurization and denitrification device, by installing an ozone distributor under a concentration sprayer or between two layers of concentration sprayers, thereby eliminating the spray cooling facility in front of the ozone distributor, eliminating the influence of the spray medium on the tail gas pipeline and the liquid level of the desulfurization and denitrification tower, realizing the integration of desulfurization and denitrification, ensuring the completeness of oxidation reaction and absorption reaction, and improving the desulfurization and denitrification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 It is a schematic diagram of the catalytic cracking tail gas ozone desulfurization and denitrification device of the utility model.
[0009] Among them: 1-oxidation section, 2-concentration section, 3-tail gas inlet, 4-third layer oxidation sprayer, 5-second layer oxidation sprayer, 6-first layer oxidation sprayer, 7-second layer concentration sprayer, 8-first layer concentration sprayer, 9-casing wall valve, 10-ozone inlet valve, 11-ozone distributor, 12-demister, 13-first layer air lifting cap, 14-second layer air lifting cap, 15-desulfurization and denitrification tower, 16-ozone pipeline, 17-flue gas outlet, 18-U-bend. DETAILED DESCRIPTION
[0010] The utility model is described in detail below with reference to the embodiments and drawings. The protection scope of the utility model is not limited to the embodiments, and any changes made by those skilled in the art within the scope defined by the claims also fall within the protection scope of the utility model.
[0011] The utility model discloses an ozone desulfurization and denitration device for catalytic cracking tail gas, comprising a desulfurization and denitration tower 15. The desulfurization and denitration tower is provided with an oxidation section 1, a concentration section 2, a tail gas inlet 3, a concentration section spray layer, an ozone distributor 11, an oxidation section spray layer, a demister 12 and a flue gas outlet 17 in sequence from bottom to top. The oxidation section spray layer is provided with three layers of oxidation sprayers, namely, a first layer of oxidation sprayer 6, a second layer of oxidation sprayer 5 and a third layer of oxidation sprayer 4. A first layer of gas lifting cap 13 is provided between the concentration section spray layer and the oxidation section spray layer, and the oxidation section is connected to the oxidation sprayer through a pipeline. The concentration section spray layer is provided with two layers of concentration sprayers, namely, a first layer of concentration sprayer 8 and a second layer of concentration sprayer 7. A second layer of gas lifting cap 14 is provided between the concentration section and the concentration section spray layer, and the concentration section is connected to the concentration sprayer through a pipeline. The ozone distributor 11 is installed between two layers of concentrated sprayers, and the ozone distributor is connected to the ozone storage tank or ozone generator through the ozone pipeline 16. A sleeve wall valve 9 is provided at the connection between the ozone distributor 11 and the ozone pipeline 16, so that the ozone distribution pipe can be disassembled online without stopping the device. The ozone pipeline 16 is provided with an upward U-shaped bend 18, and an ozone inlet valve 10 is provided at the connection between the ozone pipeline and the U-shaped bend. The demister is located at the upper part of the oxidation section spray layer, and the demister is a wet electrostatic demister. The tail gas inlet is connected to the catalytic device, and the tail gas outlet is connected to the emission system.
[0012] An ozone distributor 11 is added between the first layer of oxidation sprayer and the second layer of concentration sprayer in the spray layer of the concentration section of the desulfurization and denitration tower. The temperature in the tower is about 55°C, which has a good denitration effect. The ozone distribution pipeline is arranged symmetrically along the radial direction of the desulfurization and denitration tower, and a ball valve is installed on the wall of the desulfurization and denitration tower, so that the ozone distribution pipe can be repaired online.
[0013] After the catalytic cracking tail gas enters the desulfurization and denitrification tower through the tail gas inlet 3, it contacts with ozone in the reverse direction upward along the desulfurization and denitrification tower. Ozone, as a strong oxidant, oxidizes NO into NO2 and higher-valent nitrogen oxides. NO2 and higher-valent nitrogen oxides react with water in the spray medium to generate nitric acid and nitrous acid. The generated nitric acid and nitrous acid react with the desulfurizer in the desulfurization slurry to generate nitrates, which enter the fertilizer device together with the desulfurization and denitrification tower slurry, thereby achieving the purpose of denitrification.
Claims
1. A catalytic cracking tail gas ozone desulfurization and denitrification device, comprising a desulfurization and denitrification tower (15), characterized in that: The desulfurization and denitrification tower is provided with an oxidation section (1), a concentration section (2), a tail gas inlet (3), a concentration section spray layer, an oxidation section spray layer, a demister (12) and a flue gas outlet (17) in order from bottom to top; the oxidation section spray layer is provided with 2 to 6 layers of oxidation sprayers, and the oxidation section is connected to the oxidation sprayers through a pipeline; the concentration section spray layer is provided with 2 to 4 layers of concentration sprayers, and the concentration section is connected to the concentration sprayers through a pipeline; an ozone distributor (11) is provided in the desulfurization and denitrification tower, and the ozone distributor is installed between any two layers of oxidation sprayers or concentration sprayers, and the ozone distributor is connected to an ozone storage tank or an ozone generator through an ozone pipeline (16).
2. The catalytic cracking tail gas ozone desulfurization and denitrification device according to claim 1 is characterized in that: The oxidation section spray layer is provided with three layers of oxidation sprayers, the concentration section spray layer is provided with two layers of concentration sprayers, and the ozone distributor (11) is installed between the two layers of concentration sprayers.
3. The catalytic cracking tail gas ozone desulfurization and denitrification device according to claim 1 is characterized in that: A sleeve wall valve (9) is provided at the connection between the ozone distributor (11) and the ozone pipeline (16).
4. The catalytic cracking tail gas ozone desulfurization and denitrification device according to claim 1 is characterized in that: The ozone pipeline (16) is provided with an upward U-shaped bend (18), and an ozone inlet valve (10) is provided at the connection between the ozone pipeline and the U-shaped bend.