Chlorine and hydrogen mixed waste gas resource recycling treatment process

Abstract

The invention provides a chlorine and hydrogen mixed waste gas resourceful treatment process which is characterized in that a mixed gas dilution module, an MW-LEP waste gas treatment module, a first-stage rotating packed bed absorption module, a second-stage rotating packed bed absorption module and a control system are included in the treatment process, and the process has the advantages of being simple in system structure, small in size, safe and reliable; the investment cost is low, hydrogen and chlorine in the mixed gas are completely recycled, secondary pollution is avoided, and the emission of chlorine and hydrogen chloride in the tail gas reaches the standard. The system is widely applied to the field of three-dimensional electrolytic treatment of high-concentration chlorine-containing wastewater.

Description

Technical Field

[0001] The patent of this invention relates to the field of waste gas treatment, and in particular to a resource recovery and treatment process for chlorine-hydrogen mixed waste gas. Background Art

[0002] When using three-dimensional electrolysis to treat high-concentration chlorine-containing wastewater, a mixture of hydrogen and chlorine will be generated at the same time. The molar ratio of these two gases is the same, 1:1, and the mixed gas cannot be separated. According to the explosion limit of hydrogen in chlorine of 5%-87.5% (volume percentage), the mixed gas is an explosive gas. It is difficult to treat this gas with traditional technology, and there are great safety risks. Summary of the invention

[0003] In order to solve the explosion problem of hydrogen and chlorine mixed gas and solve the absorption and treatment problem of chlorine in tail gas, the present invention provides a chlorine and hydrogen mixed waste gas resource recovery and treatment process to solve the deficiencies of the prior art.

[0004] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0005] The present invention provides a chlorine-hydrogen mixed waste gas resource recovery and treatment process, characterized in that: the process comprises a mixed gas dilution module, a MW-LEP waste gas treatment module, a primary rotating packed bed absorption module, a secondary rotating packed bed absorption module, and a control system, wherein the mixed gas dilution module is located on the upper part of a three-dimensional electrolytic box, the mixed gas dilution module is connected to the MW-LEP waste gas treatment equipment, the MW-LEP waste gas treatment module is connected to the primary rotating packed bed absorption module, and the primary rotating packed bed absorption module is respectively connected to a hydrochloric acid storage tank and a secondary rotating packed bed absorption module.

[0006] Furthermore, the mixed gas dilution module is used to reduce the hydrogen concentration to less than 1 / 4 of the explosion limit of 7.55% (volume ratio) of the mixed gas of hydrogen, chlorine (equal to the molar number of hydrogen) and air.

[0007] Furthermore, the MW-LEP waste gas treatment equipment adopts the microwave ultraviolet waste gas treatment equipment produced by Shaanxi Qinglang Wancheng Environmental Protection Technology Co., Ltd.

[0008] Furthermore, the first-stage rotating packed bed cavity is made of hydrochloric acid corrosion-resistant stainless steel, and the generated high-concentration hydrogen chloride is initially absorbed to generate high-concentration hydrochloric acid. When the concentration of hydrochloric acid reaches 20%-35%, it is pumped into a storage tank for storage.

[0009] Furthermore, the rotating packed bed may be a high gravity rotating packed bed.

[0010] Furthermore, the first-stage rotating packed bed is also connected to a tap water replenishment tank. When the absorption liquid in the first-stage rotating packed bed is insufficient, the valve on the tap water distribution tank can be controlled to control the replenishment tank to replenish the absorption liquid into the first-stage rotating packed bed.

[0011] Furthermore, the control system is electrically connected to each module via a controller.

[0012] Furthermore, a hydrogen concentration sensor is installed in the air duct in front of the MW-LEP processing module, and a HCL concentration sensor is installed in the pipeline after the secondary rotating packed bed absorption module.

[0013] Beneficial effects of the invention: The present invention provides a chlorine-hydrogen mixed waste gas resource recovery and treatment process, characterized in that: the process comprises a mixed gas dilution module, a MW-LEP waste gas treatment module, a primary rotating packed bed absorption module, a secondary rotating packed bed absorption module, and a control system, wherein the mixed gas dilution module is located on the upper part of the three-dimensional electrolytic box, the mixed gas dilution module is connected to the MW-LEP waste gas treatment equipment, the MW-LEP waste gas treatment module is connected to the primary rotating packed bed absorption module, and the primary rotating packed bed absorption module is respectively connected to the hydrochloric acid storage tank and the secondary rotating packed bed absorption module. This patent adopts the method of air dilution first, diluting hydrogen and chlorine at the same time by more than 12.25 times, so that the concentration of hydrogen in the mixed gas of chlorine and air is less than 7.55% (volume percentage), which can solve the explosion problem and prevent the mixed gas from exploding when exposed to light or encountering sparks. The waste gas contains hydrogen and chlorine in a concentration of 1:1. During the treatment process, the two can just react chemically, H2+Cl2→HCL, generating HCL. By using secondary water absorption, a higher concentration of hydrochloric acid product can be generated and recycled for industrial occasions. At the same time, the tail gas emissions meet the standards. The process has a simple system structure, small size, and low investment cost. The hydrogen and chlorine in the mixed gas are fully utilized as resources without generating secondary pollution. It can be widely used in the field of three-dimensional electrolysis treatment of high-concentration chlorine-containing wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings in the specification without paying creative work. Figure 1 A schematic diagram of a chlorine-hydrogen mixed waste gas resource recovery and treatment process provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, rather than all the embodiments. The components of the embodiment of the present invention described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but only represents the selected embodiment of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the products of the invention in this specification are usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Figure 1 A schematic diagram of a chlorine-hydrogen mixed waste gas resource recovery and treatment process provided by an embodiment of the present invention; Figure 1 The present application is described in detail with reference to the embodiments.

[0016] The present invention provides a chlorine-hydrogen mixed waste gas resource recovery and treatment process, characterized in that: the process comprises a mixed gas dilution module, a MW-LEP waste gas treatment module, a primary rotating packed bed absorption module, a secondary rotating packed bed absorption module, and a control system, wherein the mixed gas dilution module is located on the upper part of a three-dimensional electrolytic box, the mixed gas dilution module is connected to the MW-LEP waste gas treatment equipment, the MW-LEP waste gas treatment module is connected to the primary rotating packed bed absorption module, and the primary rotating packed bed absorption module is respectively connected to a hydrochloric acid storage tank and a secondary rotating packed bed absorption module.

[0017] Furthermore, the mixed gas dilution module is used to reduce the hydrogen concentration to less than 1 / 4 of the explosion limit of 7.55% (volume ratio) of the mixed gas of hydrogen, chlorine (equal to the molar number of hydrogen) and air.

[0018] It should be noted that in the upper space of the three-dimensional electrolytic box, hydrogen and chlorine generated during the electrolysis process will emerge from the wastewater. The mixed gas dilution directly uses a fan to fill the area with air, and the air volume is greater than or equal to 12.25 times the volume of hydrogen generated by electrolysis. In the actual working process, the dilution air volume is 4 times the minimum dilution air volume, that is, about 49 times, so that the hydrogen concentration reaches less than 1 / 4 of the explosion limit of 7.55% (volume ratio) of the mixed gas of hydrogen, chlorine (equal to the molar number of hydrogen) and air, ensuring absolute safety during the treatment process. During the dilution process, the hydrogen concentration in the diluted waste gas is monitored in real time, and the fan air volume is dynamically adjusted.

[0019] Furthermore, the MW-LEP waste gas treatment equipment adopts the microwave ultraviolet waste gas treatment equipment produced by Shaanxi Qinglang Wancheng Environmental Protection Technology Co., Ltd.

[0020] Furthermore, the first-stage rotating packed bed cavity is made of hydrochloric acid corrosion-resistant stainless steel, and the generated high-concentration hydrogen chloride is initially absorbed to generate high-concentration hydrochloric acid. When the concentration of hydrochloric acid reaches 20%-35%, it is pumped into a storage tank for storage.

[0021] It should be noted that, because the oxidizing property of Cl2 is 1.06 times that of oxygen, under the combined action of microwave and ultraviolet light, H2 and Cl2 react preferentially, H2+Cl2--HCl, to generate HCl. The MW-LEP equipment uses the microwave ultraviolet waste gas treatment equipment of Shaanxi Qinglang Wancheng Environmental Protection Technology Co., Ltd., in which the equipment box and flange are made of corrosion-resistant stainless steel, and corrosion-resistant welding is also used during the welding process. The first-stage rotating packed bed cavity is made of hydrochloric acid corrosion-resistant stainless steel, which initially absorbs the generated high-concentration hydrogen chloride to generate high-concentration hydrochloric acid. When the concentration of hydrochloric acid reaches 20%-35%, it is pumped into the storage tank for storage.

[0022] Furthermore, the rotating packed bed may be a high gravity rotating packed bed.

[0023] Furthermore, the first-stage rotating packed bed is also connected to a tap water replenishment tank. When the absorption liquid in the first-stage rotating packed bed is insufficient, the valve on the tap water distribution tank can be controlled to control the replenishment tank to replenish the absorption liquid into the first-stage rotating packed bed.

[0024] Furthermore, the control system is electrically connected to each module via a controller.

[0025] Furthermore, a hydrogen concentration sensor is installed in the air duct in front of the MW-LEP processing module, and a HCL concentration sensor is installed in the pipeline after the secondary rotating packed bed absorption module.

[0026] It should be noted that the hydrogen concentration sensor is installed in the air duct in front of the MW-LEP equipment to detect the hydrogen concentration in the diluted exhaust gas in real time, and dynamically adjust the fan air volume by controlling the fan frequency controller to ensure that the concentration of hydrogen in the mixed gas is 1%; the gaseous HCl concentration sensor is installed in the pipeline behind the secondary rotating packed bed absorption equipment to detect the HCl concentration in the exhaust gas in real time, and ensure that the HCl concentration in the exhaust gas meets the standard by adjusting the rotation speed of the secondary rotating seasoning bed.

[0027] The present invention provides a chlorine-hydrogen mixed waste gas resource recovery and treatment process, characterized in that: the process comprises a mixed gas dilution module, a MW-LEP waste gas treatment module, a primary rotating packed bed absorption module, a secondary rotating packed bed absorption module, and a control system, wherein the mixed gas dilution module is located on the upper part of a three-dimensional electrolytic box, the mixed gas dilution module is connected to the MW-LEP waste gas treatment equipment, the MW-LEP waste gas treatment module is connected to the primary rotating packed bed absorption module, and the primary rotating packed bed absorption module is respectively connected to a hydrochloric acid storage tank and a secondary rotating packed absorption module. The modified process adopts the method of air dilution first, diluting hydrogen and chlorine at the same time by more than 12.25 times, so that the concentration of hydrogen in the mixed gas of chlorine and air is less than 7.55% (volume percentage), which can solve the explosion problem and prevent the mixed gas from exploding when exposed to light or encountering sparks. Because the waste gas contains hydrogen and chlorine in a concentration of 1:1, during the tail gas treatment process, the two can react chemically, H2+Cl2--HCl, to generate HCl, and then use secondary water absorption to generate a higher concentration of hydrochloric acid products, which can be reused in industrial occasions, and the tail gas emissions meet the standards. The process has a simple system structure, small size, safety and reliability, low investment cost, and the hydrogen and chlorine in the mixed gas are fully utilized as resources, without secondary pollution, and the chlorine and hydrogen chloride in the tail gas meet the emission standards. The system is widely used in the field of three-dimensional electrolysis treatment of high-concentration chlorine-containing wastewater.

Claims

1. A process for recycling and treating chlorine and hydrogen mixed waste gas, characterized in that: The process includes a mixed gas dilution module, a MW-LEP waste gas treatment module, a primary rotating packed bed absorption module, a secondary rotating packed bed absorption module, and a control system, wherein the mixed gas dilution module is located on the upper part of the three-dimensional electrolytic box, the mixed gas dilution module is connected to the MW-LEP waste gas treatment equipment, the MW-LEP waste gas treatment module is connected to the primary rotating packed bed absorption module, and the primary rotating packed bed absorption module is respectively connected to the hydrochloric acid storage tank and the secondary rotating packed bed absorption module.

2. A chlorine-hydrogen mixed gas resource recovery and treatment process according to claim 1, characterized in that: The mixed gas dilution module is used to reduce the hydrogen concentration to less than 1 / 4 of the explosion limit of 7.55% (volume ratio) of the mixed gas of hydrogen, chlorine (equal to the mole number of hydrogen) and air.

3. A chlorine-hydrogen mixed gas resource recovery and treatment process according to claim 1, characterized in that: The MW-LEP waste gas treatment equipment adopts the microwave ultraviolet waste gas treatment equipment produced by Shaanxi Qinglang Wancheng Environmental Protection Technology Co., Ltd.

4. The process for recycling and treating a chlorine-hydrogen mixed gas according to claim 1, characterized in that: The first-stage rotating packed bed cavity is made of hydrochloric acid corrosion-resistant stainless steel, and initially absorbs the generated high-concentration hydrogen chloride to generate high-concentration hydrochloric acid. When the concentration of hydrochloric acid reaches 20%-35%, it is pumped into a storage tank for storage.

5. The process for recycling and treating a chlorine-hydrogen mixed gas according to claim 1, characterized in that: The rotating packed bed may be a high gravity rotating packed bed.

6. A chlorine and hydrogen mixed gas resource recovery and treatment process according to claim 1, characterized in that: The primary rotating packed bed is also connected to a tap water replenishment tank. When the absorption liquid in the primary rotating packed bed is insufficient, the valve on the tap water distribution tank can be controlled to control the replenishment tank to replenish the absorption liquid into the primary rotating packed bed.

7. The process for recycling and treating a chlorine and hydrogen mixed gas according to claim 1, characterized in that: The control system is electrically connected to each module via a controller.

8. A chlorine and hydrogen mixed gas resource recovery and treatment process according to claim 1, characterized in that: a hydrogen concentration sensor is installed in the air duct in front of the MW-LEP treatment module, and an HCL concentration sensor is installed in the pipeline after the secondary rotating packed bed absorption module.

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