CO catalytic oxidation pilot plant test system suitable for sintering flue gas SCR denitration

Abstract

The CO catalytic oxidation pilot plant test system is arranged on the downstream of an SCR denitration device and comprises a data analysis unit, a gas taking pipeline, a flue gas heater, a pilot plant test reactor and a gas return pipeline, and the gas taking pipeline, the flue gas heater, the pilot plant test reactor and the gas return pipeline are sequentially connected. Wherein the gas taking pipeline is used for extracting flue gas in the SCR denitration device and feeding the flue gas into the flue gas heater; the flue gas heater is used for adjusting the temperature of the flue gas and feeding the flue gas into the pilot plant reactor; the pilot plant test reactor is used for completing CO catalytic oxidation reaction; and the data analysis unit is used for collecting data of the flue gas before and after the CO catalytic oxidation reaction and analyzing the data so as to obtain the CO catalytic oxidation efficiency. According to the invention, the pilot test of CO catalytic oxidation can be realized, and theoretical and practical basis is provided for the CO catalytic oxidant and engineering application thereof.

Description

Technical Field

[0001] This invention relates to the field of flue gas treatment technology, and in particular to a pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas. Background Technology

[0002] Carbon monoxide (CO) is a colorless, odorless, and non-irritating toxic gas, mainly produced by incomplete combustion. It is a significant component of air pollutants, posing a substantial threat to both the environment and human health. In response, cities in China such as Tangshan, Handan, and Linfen have issued relevant policy documents to implement CO control measures in the steel industry. On the other hand, CO has a calorific value approximately four times that of blast furnace gas, and its combustion / oxidation can release a large amount of heat, making it an excellent energy medium.

[0003] Currently, the main method for denitrification of sintering flue gas in steel enterprises is SCR (Selective Catalytic Reduction) technology. To achieve the 200-300℃ high-temperature flue gas required for the denitrification reaction, heat exchange and heating of the sintering flue gas are necessary. Conventional heating results in a temperature rise of approximately 30℃. The common practice is to add a heating furnace (external / internal) before the denitrification reactor, using blast furnace gas / coke oven gas for heating. Fuel consumption in the heating furnace accounts for 40%-60% of the total operating cost of denitrification. Furthermore, the sintering flue gas contains 5000-10000 mg / Nm³ of nitrogen. 3 According to theoretical calculations, the CO concentration in the flue gas is 1000 mg / Nm³. 3 CO can raise the temperature of sintering flue gas by about 7°C. If the heat released by the oxidation of CO in sintering flue gas can be used in a reasonable way to replace the heat released by the combustion of fuel in the heating furnace, the operating cost of denitrification can be significantly reduced while reducing CO emissions, thus achieving the dual benefits of energy saving and environmental protection.

[0004] The direct reaction between CO and O2 requires a high temperature of over 630℃. This stringent condition cannot be achieved in sintering flue gas emissions and desulfurization and denitrification purification processes. However, the temperature required for CO oxidation can be significantly reduced by using a catalyst. Therefore, developing CO catalytic oxidants and their engineering applications at a flue gas temperature of 200-300℃ for denitrification is an ideal choice for achieving energy conservation and emission reduction in sintering flue gas. In order to realize the engineering application of CO catalytic oxidation, pilot-scale testing of CO catalytic oxidation is a necessary procedure. Summary of the Invention

[0005] The purpose of this invention is to provide a pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas, which can realize pilot-scale testing of CO catalytic oxidation and provide theoretical and practical basis for CO catalytic oxidants and their engineering applications.

[0006] To achieve the above objectives, the present invention provides a pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas, arranged downstream of the SCR denitrification unit, comprising a data analysis unit and sequentially connected gas intake pipeline, flue gas heater, and pilot-scale reactor; wherein...

[0007] The gas intake pipeline is used to extract flue gas from the SCR denitrification device and send it into the flue gas heater.

[0008] The flue gas heater is used to regulate the temperature of the flue gas and feed it into the pilot reactor;

[0009] The pilot-scale reactor is used to complete the CO catalytic oxidation reaction;

[0010] The data analysis unit is used to collect and analyze data on flue gas before and after the CO catalytic oxidation reaction to obtain the CO catalytic oxidation efficiency.

[0011] Optionally, the gas intake point of the gas intake pipeline is located downstream of the denitrification reactor or upstream of the ammonia injection grid in the SCR denitrification device.

[0012] Optionally, the data analysis unit includes an inlet temperature measuring instrument and an outlet temperature measuring instrument, which are respectively installed at the inlet and outlet ends of the pilot reactor to obtain the temperature of the flue gas before and after the CO catalytic oxidation reaction in order to calculate the CO catalytic oxidation efficiency.

[0013] Optionally, the data analysis unit includes an inlet flue gas analyzer and an outlet flue gas analyzer, which are respectively installed at the inlet and outlet of the pilot reactor to obtain the CO concentration of the flue gas before and after the CO catalytic oxidation reaction in order to calculate the CO catalytic oxidation efficiency.

[0014] Optionally, the data analysis unit further includes a central control center, which is used to analyze the collected data and calculate the CO catalytic oxidation efficiency.

[0015] Optionally, the data analysis unit further includes a flow meter, which is disposed at the inlet end of the pilot reactor.

[0016] Optionally, the data analysis unit further includes a differential pressure gauge, which is used to measure the pressure difference between the inlet and outlet of the pilot reactor.

[0017] Optionally, the CO catalytic oxidation pilot-scale system further includes an electrically controlled regulating valve for regulating the amount of flue gas entering the pilot-scale reactor.

[0018] Optionally, the CO catalytic oxidation pilot system further includes a return gas pipeline, the two ends of which are connected to the pilot reactor and the denitrification flue gas outlet of the SCR denitrification device, respectively, and an induced draft fan is also installed on the return gas pipeline.

[0019] Optionally, the gas intake pipeline and the gas return pipeline are respectively equipped with on / off valves.

[0020] This invention provides a pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas, which has at least one of the following beneficial effects:

[0021] 1) It can realize comprehensive pilot-scale experiments on CO catalytic oxidation, providing theoretical and practical basis for CO catalytic oxidants and their engineering applications;

[0022] 2) By setting the gas intake point of the gas intake pipeline on the flue gas duct after the heating furnace of the SCR denitrification unit (downstream of the denitrification reactor or upstream of the ammonia injection grid), the flue gas temperature is the SCR denitrification reaction temperature, which is in the active range of the CO oxidation catalyst and is also the most reasonable reaction temperature of the actual CO oxidation catalyst in engineering applications, which meets the purpose of simulating the actual flue gas temperature in pilot-scale testing.

[0023] 3) By setting the return gas port at the denitrification flue gas outlet of the SCR denitrification unit (i.e., the downstream flue gas duct of the flue gas heat exchanger), the flue gas pressure here is more than 500Pa lower than that at the gas intake port. This can reduce the energy consumption of the fan operation and ensure that the flue gas can pass smoothly through the pilot plant when the induced draft fan fails, so that the pilot test can be carried out for a short time without being forced to stop the test.

[0024] 4) By setting up a flue gas heater to raise the temperature of the flue gas entering the pilot system, it is possible to compensate for the temperature drop caused by the flue gas outlet and adjust the flue gas temperature according to the requirements of the pilot test, thereby achieving the test objective.

[0025] 5) By setting up a remote wireless transmission control center to regulate various instruments and equipment, real-time monitoring of remote computers, mobile phones and other terminal devices can be achieved, which not only ensures the safe and stable operation of the pilot system, but also allows for real-time monitoring of the pilot process and test data. Attached Figure Description

[0026] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0027] Figure 1 This is a schematic diagram of the CO catalytic oxidation pilot system for SCR denitrification of sintering flue gas provided in Embodiment 1 of the present invention.

[0028] in:

[0029] 101-Gas intake pipeline; 102-Flue gas heater; 103-Pilot reactor; 104-Return gas pipeline; 105-Thermometer; 106-Inlet thermometer; 107-Outlet thermometer; 108-Inlet flue gas analyzer; 109-Outlet flue gas analyzer; 110-Central control center; 111-Flow meter; 112-Differential pressure gauge; 113-Electric regulating valve; 114-Induced draft fan; 115-On / off valve; 201-Flue gas heat exchanger; 202-Heating furnace; 203-Ammonia injection grid; 204-Denitrification reactor. Detailed Implementation

[0030] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0031] As used herein, the singular forms “a,” “an,” and “the” include plural objects unless otherwise expressly indicated. As used herein, the term “or” is generally used to include “and / or” unless otherwise expressly indicated. As used herein, the term “a number” is generally used to include “at least one” unless otherwise expressly indicated. As used herein, the term “at least two” is generally used to include “two or more” unless otherwise expressly indicated. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature.

[0032] Please refer to Figure 1 This embodiment provides a pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas, arranged downstream of the SCR denitrification unit. It includes a data analysis unit and sequentially connected components such as a gas intake pipe 101, a flue gas heater 102, a pilot-scale reactor 103, and a return gas pipe 104.

[0033] The gas intake pipeline 101 is used to extract flue gas from the SCR denitrification unit and send it into the flue gas heater 102.

[0034] Flue gas heater 102 is used to regulate the temperature of flue gas and feed it into pilot reactor 103;

[0035] Pilot reactor 103 is used to complete the CO catalytic oxidation reaction;

[0036] The data analysis unit is used to collect and analyze data on flue gas before and after the CO catalytic oxidation reaction to obtain the CO catalytic oxidation efficiency.

[0037] The CO catalytic oxidation pilot-scale system provided in this embodiment is arranged downstream of an existing sintering flue gas SCR denitrification device. The SCR denitrification device includes a flue gas heat exchanger 201 (GGH) and sequentially connected components such as a heating furnace 202, an ammonia injection grid 203, and an SCR denitrification reactor 204. Since this SCR denitrification device is common knowledge, its specific working principle will not be described in detail in this invention. In this embodiment, the gas intake point of the gas intake pipe 101 is set on the flue gas duct after the heating furnace 202. The flue gas temperature is high (usually 250-280℃), which is the SCR denitrification reaction temperature. This is within the active range of the CO oxidation catalyst and is also the most reasonable reaction temperature for actual CO oxidation catalysts used in engineering applications (CO oxidation catalysts are usually arranged inside the SCR reactor), which meets the purpose of simulating the actual flue gas temperature in the pilot-scale test.

[0038] Preferably, the gas intake point of the gas intake pipe 101 is located downstream of the denitrification reactor 204 or upstream of the ammonia injection grid 203 in the SCR denitrification unit. By setting the gas intake point in the flue upstream of the ammonia injection grid 203, the flue gas temperature is ensured, and no ammonia is mixed in with the flue gas, thus avoiding the influence of ammonia on the CO oxidation catalyst. Alternatively, the gas intake point can be set in the flue downstream of the denitrification reactor 204, since the denitrification reaction has been completed, the NO in the flue gas is already low. x Both the escaped NH3 and the NH3 are at their lowest points, which can achieve NO x The study on the effect of NH3 on CO oxidation catalysts shows that gas sampling points can be reasonably arranged according to the needs of pilot-scale testing, and this invention does not impose any restrictions on this.

[0039] In this embodiment, the flue gas heater 102 is used to heat the flue gas entering the CO catalytic oxidation pilot system. This not only compensates for the temperature drop caused by the exhaust duct, but also allows for temperature adjustment according to the pilot test requirements, thus facilitating the achievement of the experimental objectives. For example, the flue gas heater 102 can heat the flue gas from 0-80°C as needed. The temperature-adjusted flue gas then flows into the pilot reactor 103 for CO catalytic oxidation under the action of the CO oxidation catalyst.

[0040] Optionally, the flue gas heater 102 can be a direct-fired furnace 202 or an electric heater. The direct-fired furnace 202 can rapidly heat the flue gas to reach the catalyst activation temperature quickly, while the electric heater uses green electricity, which can further reduce the company's carbon emissions and help achieve green production goals. This invention does not limit this.

[0041] In this embodiment, a temperature measuring instrument 105 is also provided at the inlet end (i.e., the gas intake pipe 101) of the flue gas heater 102 to detect the flue gas temperature before heating. The flue gas temperature can be transmitted to the central control center, and the heating temperature of the flue gas heater 102 can be remotely controlled by the central control center.

[0042] As a feasible embodiment, the data analysis unit includes an inlet temperature sensor 106 and an outlet temperature sensor 107. The inlet temperature sensor 106 and the outlet temperature sensor 107 are respectively installed at the inlet and outlet ends of the pilot reactor 103 to obtain the temperature of the flue gas before and after the CO catalytic oxidation reaction, in order to calculate the CO catalytic oxidation efficiency. By measuring the temperature change of the flue gas before and after the pilot reactor 103, the CO catalytic oxidation efficiency can be calculated based on the heat released during the CO oxidation reaction.

[0043] As another feasible embodiment, the data analysis unit includes an inlet flue gas analyzer 108 and an outlet flue gas analyzer 109. The inlet and outlet flue gas analyzers 108 and 109 are respectively located at the inlet and outlet ends of the pilot-scale reactor 103, and are used to obtain the CO concentration in the flue gas before and after the CO catalytic oxidation reaction for calculating the CO catalytic oxidation efficiency. The flue gas analyzers can detect SO2 and NO in the flue gas before and after the pilot-scale reactor 103 in real time. x Based on the detection of CO concentrations before and after the reaction, the CO catalytic oxidation efficiency can be directly calculated from the components such as CO.

[0044] Preferably, the two calculation methods mentioned above can be used simultaneously to facilitate mutual verification and avoid problems such as pilot-scale tests being forced to stop due to a single tester malfunction.

[0045] In this embodiment, the data analysis unit also includes a central control center 110, which is used to analyze the collected data and calculate the CO catalytic oxidation efficiency. This central control center 110 is, for example, a PLC control system. It should be noted that the various instruments and equipment involved in the CO catalytic oxidation pilot-scale system provided by this invention, such as the flue gas heater 102, thermometer 105, flue gas analyzer, flow meter 111, differential pressure gauge 112, and electric regulating valve 113, all have remote monitoring functions. They can be centrally controlled through the central control center 110 and can also be transmitted via wireless network to achieve real-time monitoring by remote computers, mobile phones, and other terminal devices. This ensures the safe and stable operation of the pilot-scale system while allowing real-time monitoring of the pilot-scale process and experimental data.

[0046] In this embodiment, the data analysis unit also includes a flow meter 111, which is installed at the inlet of the pilot reactor 103 to measure the flow rate of the flue gas undergoing the CO catalytic oxidation reaction. The flow meter 111 can be used as an operating condition monitoring indicator to evaluate the catalytic oxidation efficiency of the CO oxidation catalyst.

[0047] In this embodiment, the data analysis unit also includes a differential pressure gauge 112, which is used to measure the pressure difference between the inlet and outlet of the pilot reactor 103 in order to monitor the bed pressure drop of the CO oxidation catalyst.

[0048] Preferably, the CO catalytic oxidation pilot-scale system further includes an electrically controlled regulating valve 113, which is used to regulate the amount of flue gas entering the pilot-scale system. In this embodiment, the electrically controlled regulating valve 113 can remotely and conveniently regulate the amount of flue gas entering the pilot-scale system to achieve pilot-scale experiments at different space velocities. In addition, the configuration of the electrically controlled regulating valve 113 allows for remote start-up and shutdown of the pilot-scale system, which is convenient for pilot-scale operation and ensures the safe operation of the pilot-scale system. The electrically controlled regulating valve 113 can be installed on the gas intake pipe 101, the flue gas ducts before and after the pilot-scale reactor 103, or the return gas pipe 104. The present invention does not limit this. In this embodiment, the electrically controlled regulating valve 113 is installed on the return gas pipe 104 and located between the pilot-scale reactor 103 and the induced draft fan 114.

[0049] Preferably, the CO catalytic oxidation pilot system also includes a return gas pipeline 104, with its two ends connected to the pilot reactor 103 and the denitrification flue gas outlet of the SCR denitrification unit, respectively. An induced draft fan 114 is installed on the return gas pipeline 104. By setting the return gas outlet at the denitrification flue gas outlet of the SCR denitrification unit (i.e., the downstream flue of the flue gas heat exchanger 201), where the flue gas pressure is more than 500 Pa lower than that at the gas inlet, the energy consumption of the fan can be reduced, and the flue gas can still pass smoothly through the pilot unit in the event of a failure of the induced draft fan 114, allowing the pilot test to proceed for a short period of time without being forced to stop.

[0050] Preferably, an on / off valve 115 is provided on the gas intake line 101 and the gas return line 104 respectively. The on / off valve 115 is normally opened during pilot test and closed when pilot test is not required or when the pilot system is under maintenance. The on / off valve 115 is, but is not limited to, a manual valve or an automatic valve.

[0051] The specific process of the CO catalytic oxidation pilot-scale system provided in this embodiment is as follows:

[0052] Flue gas is drawn from the intake port located upstream of the ammonia injection grid 203 or downstream of the denitrification reactor 204, and enters the flue gas heater 102 through the intake pipe 101. After temperature regulation, it enters the pilot reactor 103. Under the action of the CO oxidation catalyst, CO in the flue gas undergoes a catalytic oxidation reaction with O2 in the flue gas. The flue gas after the reaction is then sent to the downstream flue of the flue gas heat exchanger 201 by the induced draft fan 114. At the same time, temperature measuring instruments 105 are installed upstream of the flue gas heater 102, upstream and downstream of the pilot reactor 103, respectively. Differential pressure gauges 112 are installed before and after the pilot reactor 103 to detect the pressure drop of the catalyst bed, and online flue gas detectors are installed before and after the pilot reactor 103 to detect the CO concentration in the flue gas. Parameters such as flue gas temperature rise, pressure difference, and CO catalytic oxidation efficiency are obtained, thereby realizing the temperature control of the CO pilot reaction, monitoring of the catalyst bed pressure drop, and calculation and monitoring of CO conversion rate, ultimately achieving the purpose of the pilot test. In addition, by setting up a remote wireless transmission control center 110, remote monitoring and control of the pilot system can be achieved through terminal devices such as computers and mobile phones. Through comprehensive pilot-scale experiments, theoretical and practical basis can be provided for CO catalytic oxidant and its engineering applications.

[0053] In summary, the embodiments of the present invention provide a pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas, which can realize comprehensive pilot-scale tests of CO catalytic oxidation, and provide theoretical and practical basis for CO catalytic oxidants and their engineering applications.

[0054] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the scope of protection of the present invention.

Claims

1. A pilot-scale CO catalytic oxidation system suitable for SCR denitrification of sintering flue gas, arranged downstream of an SCR denitrification unit, characterized in that, It includes a data analysis unit and sequentially connected gas intake pipelines, flue gas heaters, and pilot-scale reactors; among which, The gas intake pipeline is used to extract flue gas from the SCR denitrification device and send it into the flue gas heater. The flue gas heater is used to regulate the temperature of the flue gas and feed it into the pilot reactor; The pilot-scale reactor is used to complete the CO catalytic oxidation reaction; The data analysis unit is used to collect and analyze data on flue gas before and after the CO catalytic oxidation reaction to obtain the CO catalytic oxidation efficiency.

2. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The gas intake point of the gas intake pipeline is located downstream of the denitrification reactor or upstream of the ammonia injection grid in the SCR denitrification device.

3. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The data analysis unit includes an inlet temperature measuring instrument and an outlet temperature measuring instrument, which are respectively installed at the inlet and outlet ends of the pilot reactor to obtain the temperature of the flue gas before and after the CO catalytic oxidation reaction in order to calculate the CO catalytic oxidation efficiency.

4. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The data analysis unit includes an inlet flue gas analyzer and an outlet flue gas analyzer, which are respectively installed at the inlet and outlet of the pilot reactor. They are used to obtain the CO concentration of the flue gas before and after the CO catalytic oxidation reaction in order to calculate the CO catalytic oxidation efficiency.

5. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The data analysis unit also includes a central control center, which is used to analyze the collected data and calculate the CO catalytic oxidation efficiency.

6. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The data analysis unit also includes a flow meter, which is installed at the inlet end of the pilot reactor.

7. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The data analysis unit also includes a differential pressure gauge, which is used to measure the pressure difference between the inlet and outlet of the pilot reactor.

8. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The CO catalytic oxidation pilot-scale system also includes an electrically operated regulating valve, which is used to regulate the amount of flue gas entering the pilot-scale reactor.

9. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 1, characterized in that, The CO catalytic oxidation pilot system also includes a return gas pipeline, the two ends of which are connected to the pilot reactor and the denitrification flue gas outlet of the SCR denitrification device, respectively. An induced draft fan is also installed on the return gas pipeline.

10. The pilot-scale CO catalytic oxidation system for SCR denitrification of sintering flue gas as described in claim 9, characterized in that, The gas intake pipeline and the gas return pipeline are respectively equipped with on / off valves.

Images