System for enriching, purifying and recycling multiple pollutants in industrial flue gas

Abstract

The utility model discloses a system for enriching, purifying and recycling multiple pollutants in industrial flue gas, and belongs to the technical field of energy conservation and environmental protection. The system comprises an adsorption tower, an airflow converter, a denitration reactor and a sulfur generator. Industrial flue gas passes through an activated carbon adsorption layer and a combined selective adsorption film in the adsorption tower, then enters the gas flow converter, and respectively enters the denitration reactor and the sulfur generator for desulfurization, denitration and sulfur recycling through the regulation effect of the gas flow converter according to the flue gas type. By adopting the system, various pollutants such as sulfur dioxide and nitrogen oxide in the flue gas can be efficiently removed, meanwhile, high-concentration sulfur dioxide in the sulfur-rich flue gas generated by regeneration of the adsorption tower is subjected to resource utilization, and economic benefits are increased while environmental protection is facilitated.

Description

Technical Field

[0001] The utility model relates to the field of multi-pollutant treatment and sulfur resource utilization of industrial flue gas, and particularly relates to a system for enriching, purifying and resource-utilizing multi-pollutants in industrial flue gas. Background Art

[0002] At the present stage, the conventional treatment of SO2 mainly includes wet, dry and semi-dry flue gas desulfurization. Although the conventional desulfurization process is relatively mature, the utilization rate of by-products such as desulfurized gypsum and desulfurized ash generated by the reaction is extremely low, and they are generally treated by stacking, landfilling, etc., occupying a large amount of land area and being prone to environmental problems such as secondary pollution. Industrial flue gas usually contains multiple pollutants such as NO and SO2 at the same time. The series use of conventional multiple treatment devices brings high investment and operation costs. Therefore, there is an urgent need for a treatment system that can simultaneously remove multiple pollutants in flue gas and achieve green and clean treatment.

[0003] ZL200910112733.33 proposes a dry flue gas purification method and device for simultaneous desulfurization and denitrification. The purification device is provided with an inlet flue, an absorption tower, a dust collector, a material circulation air chute, an absorbent bin, a water tank, a water pump, an atomizing spray gun and an outlet flue. The flue gas purification is finally completed through the dry flue gas purification process, but the sulfur resources contained in the flue gas are not utilized. ZL201010039505.0 discloses a device and method for simultaneous removal of multiple pollutants by electrocatalytic oxidation combined with lime-gypsum method. The device includes a spray cooling device, an electrostatic enhancement reactor, a Venturi device, a double-cycle multi-pollutant integrated absorption tower, and a wet electrostatic demister. The flue gas is cooled by the spray cooling device and then enters the electrostatic enhancement reactor. The flue gas is subjected to corona discharge treatment in the corona discharge area formed in the electrostatic enhancement reactor. The treated flue gas enters the double-cycle multi-pollutant integrated absorption tower, where it is subjected to spray dust removal and spray absorption. The purified flue gas sequentially enters the corrugated plate demister and the electrostatic demister at the upper part of the spray tower to remove the aerosol in the flue gas. Although this method can achieve simultaneous removal of multiple pollutants and high removal efficiency of various pollutants, it also fails to effectively utilize the sulfur resources in industrial flue gas and generates secondary pollution such as desulfurized gypsum. Summary of the Utility Model

[0004] In order to solve the above-mentioned defects and deficiencies in the prior art, the utility model provides a system for enriching, purifying and resource-utilizing multi-pollutants in industrial flue gas, which solves the problem of multi-pollutant compound pollution of sulfur dioxide and nitrogen oxides in industrial flue gas, and realizes the high-value utilization of sulfur resources in industrial flue gas at the same time.

[0005] The purpose of the utility model can be realized by the following technical solutions:

[0006] A system for enriching, purifying and resource - utilizing multiple pollutants in industrial flue gas. The system includes at least one adsorption tower, an air - flow converter and a denitration reactor. The output end at the top of the adsorption tower is connected to the air - flow converter, and the two output ends of the air - flow converter are respectively connected to the denitration reactor and a sulfur generator.

[0007] In the technical solution of the present utility model: a heater is provided inside the adsorption tower, and several activated - carbon adsorption layers are provided inside the adsorption tower. A combined selective adsorption membrane is provided above the activated - carbon adsorption layer.

[0008] In the technical solution of the present utility model: a desulfurization catalyst layer is provided between the air - flow converter and the sulfur generator.

[0009] In the technical solution of the present utility model: an ammonia - injection module is provided between the air - flow converter and the denitration reactor.

[0010] In the technical solution of the present utility model: 1 - 3 desulfurization catalyst layers are provided in the denitration reactor.

[0011] In the technical solution of the present utility model: a liquid - nitrogen condensing pipe is provided outside the sulfur generator.

[0012] In the technical solution of the present utility model: the sulfur generator is connected to a sulfur collection hopper.

[0013] The system involved in the technical solution of the present utility model includes four parts. The first part is the adsorption tower, the second part is the air - flow converter, the third part is the denitration reactor, and the fourth part is the sulfur generator. The flue gas first enters the adsorption tower to remove sulfur dioxide and nitrogen oxides, and then enters the air - flow converter. According to the operating conditions, the adsorbed flue gas is connected to the denitration reactor for further denitration, while the regenerated flue gas is connected to the sulfur generator and is converted into gaseous sulfur through catalytic reduction technology and then condensed and collected to obtain solid sulfur. The purified clean flue gas is finally discharged up to the standard.

[0014] In the technical solution of the present utility model: a heater is provided outside the adsorption tower, and the heating function is controlled by a heating control unit. An activated - carbon adsorption layer is provided in the middle, and a combined selective adsorption membrane is provided at the top.

[0015] In the technical solution of the present utility model: an ammonia - injection module is provided at the front section of the denitration reactor, and a denitration catalyst layer is provided in the middle.

[0016] In the technical solution of the present utility model: the front part of the sulfur generator is a desulfurization catalyst layer, a liquid - nitrogen condensing pipe is provided in the middle, and a sulfur collection hopper is provided at the tail.

[0017] In the technical solution of the present utility model: the heating control unit includes a temperature detection module, a heating control module, a leakage protection module and a control panel. The temperature detection module is used to monitor the regeneration temperature during the regeneration of the adsorption tower. The heating control module is used for programmed temperature rise setting. The leakage protection module is used to prevent safety problems caused by system leakage. The control panel is used to monitor the conditions of each module and perform real-time regulation.

[0018] In the technical solution of the present utility model: the catalyst used in the denitration catalyst layer is mainly one or more of the vanadium molybdenum, vanadium tungsten, manganese cerium, manganese iron, cerium tungsten series catalysts.

[0019] In the technical solution of the present utility model: the catalyst in the desulfurization catalyst layer is a rare earth-based catalyst with rare earth element cerium as the main active component.

[0020] In the technical solution of the present utility model: the regeneration temperature of the activated carbon adsorption layer and the combined selective adsorption membrane of the adsorption tower is 400 - 450 °C.

[0021] In the technical solution of the present utility model, the application of the system for enriching, purifying and recycling multiple pollutants in industrial flue gas in the treatment of multiple pollutants in industrial flue gas and sulfur resource recycling.

[0022] The beneficial effects of the present utility model are as follows:

[0023] (1) Compared with the conventional wet flue gas desulfurization technology, the present utility model can avoid problems such as secondary pollution, occupation of a large amount of land area, equipment corrosion, and high investment and operation costs. At the same time, it can convert SO2 in the flue gas into elemental sulfur, alleviating the problem of shortage of sulfur resources in our country.

[0024] (2) The series connection of the air flow converter and the adsorption tower regeneration realizes the uninterrupted operation of the desulfurization and denitration system, reducing the operation cost of the environmental protection device.

[0025] (3) The present system uses a short-process process form to simultaneously remove nitrogen oxides and sulfur dioxide in industrial flue gas. At the same time, the sulfur dioxide in the regeneration flue gas can be effectively enriched and recycled, reducing the treatment difficulty of sulfur-rich flue gas.

[0026] (4) The present application proposes a system for enriching, purifying and recycling multiple pollutants in industrial flue gas. This system realizes the removal of pollutants such as sulfur dioxide and nitrogen oxides in industrial flue gas. At the same time, the sulfur resources in industrial flue gas are enriched and converted into high-value-added sulfur, reducing the process energy consumption and significantly increasing the economic benefits. Description of the Drawings

[0027] Figure 1 is the system for enriching, purifying and recycling multiple pollutants in industrial flue gas of the present utility model.

[0028] Meanings of the reference numerals: 1 is an adsorption tower, 2 is an air flow converter, 3 is a denitration reactor, 4 is a sulfur generator, 5 is a heater, 6 is a heating control unit, 7 is an activated carbon adsorption layer, 8 is a combined selective adsorption membrane, 9 is an ammonia injection module, 10 is a denitration catalyst layer, 11 is a desulfurization catalyst layer, 12 is a liquid nitrogen condensing pipe, and 13 is a sulfur collection hopper. Detailed implementation manners

[0029] The present utility model will be further described below in conjunction with embodiments, but the protection scope of the present utility model is not limited thereto:

[0030] As Figure 1 shown, a system for enriching, purifying and resource recycling of multi-pollutants in industrial flue gas, the system includes at least one adsorption tower 1, an air flow converter 2 and a denitration reactor 3. The output end at the top of the adsorption tower 1 is connected to the air flow converter 2, and the two output ends of the air flow converter 2 are respectively connected to the denitration reactor 3 and the sulfur generator 4. A heater 5 is arranged inside the adsorption tower 1, and several layers of activated carbon adsorption layers 7 are arranged inside the adsorption tower 1, and a combined selective adsorption membrane 8 is arranged above the activated carbon adsorption layer 7. A desulfurization catalyst layer 11 is arranged between the air flow converter 2 and the sulfur generator 4. An ammonia injection module 9 is arranged between the air flow converter 2 and the denitration reactor 3. There are 1 to 3 layers of desulfurization catalyst layers 11 in the denitration reactor 3. A liquid nitrogen condensing pipe 12 is arranged outside the sulfur generator 4. The sulfur generator 4 is connected to the sulfur collection hopper 13.

[0031] The working process is as follows: The flue gas first enters the adsorption tower for removal of sulfur dioxide and nitrogen oxides, and then enters the air flow converter. According to the operating conditions, the adsorbed flue gas is connected to the denitration reactor for further denitration, while the regenerated flue gas is connected to the sulfur generator and converted into gaseous sulfur through catalytic reduction technology and then condensed and collected to obtain solid sulfur. The purified clean flue gas is finally discharged up to the standard. The catalyst used in the denitration catalyst layer 10 mainly has an activity of one or more of vanadium molybdenum, vanadium tungsten, manganese cerium, manganese iron, and cerium tungsten series catalysts. The catalyst in the desulfurization catalyst layer 11 is a rare earth-based system catalyst with rare earth element cerium as the main active component. The regeneration temperature of the activated carbon adsorption layer and the combined selective adsorption membrane in the adsorption tower 1 is 400 - 450 °C.

[0032] The specific working process and principle of the present utility model:

[0033] Industrial flue gas enters the system pipeline and first passes through the activated carbon adsorption layer and the combined selective adsorption membrane in the adsorption tower to achieve the efficient removal of sulfur dioxide and the preliminary removal of nitrogen oxides. Subsequently, the flue gas enters the gas flow converter. The flue gas in the unsaturated state adsorbed by the adsorption tower is connected to the denitration reactor through the gas flow converter for denitration treatment. Under the action of the denitration catalyst and the reducing agent ammonia, nitrogen oxides are catalytically converted into nitrogen and water and then discharged up to the standard; the adsorption tower saturated with adsorption is heated and regenerated under the control of the heating control unit. At a temperature of 400-450 °C, the sulfur dioxide adsorbed by the activated carbon and the selective adsorption membrane is desorbed. At this time, the concentration of sulfur dioxide in the desorbed and enriched flue gas is much higher than that of the flue gas under normal working conditions. The sulfur-rich flue gas after desorption is connected to the sulfur generator through the gas flow converter. Sulfur dioxide is catalytically converted into gaseous sulfur and then condensed into solid sulfur by the rapid cooling area arranged by the liquid nitrogen condenser tube for collection. Using this device can achieve the efficient removal of various pollutants such as sulfur dioxide and nitrogen oxides in the flue gas, and at the same time, the high-concentration sulfur dioxide in the sulfur-rich flue gas generated by the regeneration of the adsorption tower is recycled, which is beneficial to environmental protection and increases economic benefits.

[0034] The above is only the preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments of the equivalent changes within the scope of the technical solution of the present invention without departing from the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

[0035] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope that can be covered by the technical content disclosed in the present invention without affecting the efficacy and purpose that the present invention can achieve.

Claims

1. A system for enriching, purifying and recycling multiple pollutants in industrial flue gas, characterized by: The system comprises at least one adsorption tower (1), an airflow converter (2) and a denitration reactor (3), wherein the output end at the top of the adsorption tower (1) is connected to the airflow converter (2), and the two output ends of the airflow converter (2) are respectively connected to the denitration reactor (3) and the sulfur generator (4).

2. The system for enriching, purifying and recycling industrial flue gas pollutants according to claim 1 is characterized by: A heater (5) is provided on the inner side of the adsorption tower (1), and a plurality of activated carbon adsorption layers (7) are provided inside the adsorption tower (1), and a combined selective adsorption membrane (8) is provided above the activated carbon adsorption layer (7).

3. The system for enriching, purifying and recycling industrial flue gas pollutants according to claim 1 is characterized by: A desulfurization catalyst layer (11) is provided between the airflow converter (2) and the sulfur generator (4).

4. The system for enriching, purifying and recycling industrial flue gas pollutants according to claim 1 is characterized by: An ammonia injection module (9) is provided between the airflow converter (2) and the denitration reactor (3).

5. The system for enriching, purifying and recycling industrial flue gas pollutants according to claim 4 is characterized by: One to three desulfurization catalyst layers (11) are provided in the denitration reactor (3).

6. The system for enriching, purifying and recycling industrial flue gas pollutants according to claim 1 is characterized by: A liquid nitrogen condenser (12) is provided outside the sulfur generator (4).

7. The system for enriching, purifying and recycling industrial flue gas pollutants according to claim 1 is characterized by: The sulfur generator (4) is connected to the sulfur collecting hopper (13).

Images