An online detection system for organic amine volatile gas

Abstract

The utility model relates to the field of environmental control technology, concretely relates to an organic amine volatile gas on -line detection system, can carry out on -line monitoring and carries out the targeted optical detection to the volatile component of organic amine solution in carbon dioxide capture system. Organic amine solution volatile gas on -line detection system of the present application, through the waste gas in the carbon capture export or the analysis tower export pipeline is gathered and after the temperature, flow of sample gas etc. Pretreatment, finally utilizes the differential absorption characteristic of ethanol amine in ultraviolet wave band, realizes the on -line, automatic measurement and alarm of ethanol amine concentration through UV-DOAS ultraviolet differential method.

Description

Technical Field

[0001] This utility model relates to the field of environmental control technology, specifically to an online detection system for volatile organic amine gases. Background Technology

[0002] In the context of dual carbon emissions, chemical absorption based on organic amines is a widely used and highly efficient carbon dioxide capture technology. Organic amines, as absorbents, offer advantages such as high collection efficiency and renewability. However, currently used organic amine solutions (commonly mixtures of ethanolamine and water) release ethanolamine gas during use, which is then discharged into the environment through pipelines, polluting the ecosystem and harming occupational health. Currently, the main analytical method for organic amines is chromatography; however, chromatography suffers from drawbacks such as complex equipment systems, long analysis cycles, difficult operation and maintenance, and the inability to perform online measurements. Utility Model Content

[0003] In view of this, the present invention provides an online detection system for volatile gases based on organic amines, which can monitor and perform targeted optical detection of volatile components based on organic amine solutions in a carbon dioxide capture system online.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows:

[0005] An online detection system for volatile organic amine gases includes:

[0006] High-temperature pretreatment gas path system: used to collect sample gas from the carbon capture outlet or desorption tower outlet pipeline, and to perform anti-condensation transmission and water removal treatment on the sample gas;

[0007] Ethanolamine gas analyzer: Connected to the pretreatment gas path system, it detects the concentration of organic amines in the sample gas based on the UV-DOAS ultraviolet differential absorption principle;

[0008] Control system: Connected to the pretreatment gas circuit system and the gas analyzer respectively, to realize sampling control, concentration calculation and alarm functions;

[0009] The high-temperature pretreatment gas path system includes the following components connected in sequence:

[0010] A sampling probe with a built-in high-temperature filter is used for primary filtration of particulate matter;

[0011] Thermostatic heating pipeline is used to maintain the sample gas temperature at 180–200℃;

[0012] A drain filter and peristaltic pump are used to achieve gas-liquid separation and automatically discharge liquid water;

[0013] The valve group, consisting of three-way valve 1 and three-way valve 2, is used to switch between measurement, zeroing, and calibration modes;

[0014] The ethanolamine gas analyzer includes:

[0015] Xenon lamp light source, gas chamber and spectrometer, used for differential absorption spectroscopy analysis in the 200–230 nm wavelength range.

[0016] The operating modes of the valve assembly include:

[0017] Measurement mode: Three-way valve 1 and three-way valve 2 are de-energized, and the sample gas flows directly into the gas chamber;

[0018] Zeroing mode: Three-way valve 1 is energized, three-way valve 2 is de-energized, and ambient air is introduced into the air chamber after being purified by molecular sieve and filter;

[0019] Calibration mode: Three-way valve 2 is energized and three-way valve 1 is de-energized, the calibration gas enters the gas chamber and the backflow of the sample gas is blocked.

[0020] The drain filter is located inside the heating box and discharges the separated liquid water in real time via a peristaltic pump.

[0021] The control system includes:

[0022] The gas analysis and control unit is used to perform heat tracing temperature control, start and stop of the gas pump, concentration inversion and alarm for exceeding the limit;

[0023] The display screen is used to show concentration data and alarm information in real time.

[0024] The pretreatment gas path system further includes:

[0025] An orifice plate flow meter, located at the outlet of the gas chamber, is used to regulate the sample gas flow rate;

[0026] An air pump provides sampling power and vents the gas after detection.

[0027] The zero-adjustment mode uses ambient air that has been filtered through a molecular sieve to adsorb moisture and particulate matter as zero air.

[0028] The spectrometer receives the light emitted from the gas cell via an optical fiber and analyzes the characteristic absorption spectrum of ethanolamine in the 200–230 nm wavelength range.

[0029] Beneficial effects:

[0030] 1. The present invention relates to an online detection system for volatile gases from organic amine solutions. By collecting waste gas from the outlet of a carbon capture tower or the outlet of a desorption tower and pre-treating it by measuring the temperature and flow rate of the sample gas, the system utilizes the differential absorption characteristics of ethanolamine in the ultraviolet band to achieve online and automatic measurement and alarm of ethanolamine concentration through the UV-DOAS ultraviolet differential method.

[0031] 2. In this invention, the entire gas path is kept under constant high-temperature heating, effectively eliminating interference from condensate and improving the stability and accuracy of measurements. Simultaneously, the system features automatic zeroing and automatic calibration functions.

[0032] 3. Compared with chromatographic systems, this utility model system is more complex (such as separation systems), has a longer detection cycle (minutes), requires consumables (such as chromatographic columns), and cannot achieve automated measurement (requiring manual sampling). The system adopts a modular design, is simple and reliable, and has complete functions. It also has the performance characteristics of high measurement accuracy, good reliability, convenient maintenance, and strong anti-interference ability. It can quickly and accurately detect the leakage and escape of ethanolamine gas in carbon dioxide capture devices.

[0033] 4. This utility model system integrates sampling and transmission, data processing and analysis, and display and alarm functions. The gas path within the system is maintained at a constant high temperature with heat tracing, effectively eliminating interference from condensate and improving the stability and accuracy of measurements. Simultaneously, the system features automatic zeroing and automatic calibration functions. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of an online detection system for volatile organic amine gases according to an embodiment of this utility model.

[0035] Figure 2 This is a schematic diagram of the flow control logic of the online detection system for volatile organic amine gases according to an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of the differential absorption spectrum of an embodiment of the present invention. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] This invention provides an online detection system for volatile gases from organic amine solutions. It collects waste gas from the outlet of a carbon capture tower or the outlet of a desorption tower, pre-treats the gas by controlling its temperature and flow rate, and finally utilizes the differential absorption characteristics of ethanolamine in the ultraviolet band to achieve online, automatic measurement and alarm of ethanolamine concentration using the UV-DOAS ultraviolet differential method. The system composition of this embodiment is as follows: Figure 1 As shown, the system includes a high-temperature pretreatment gas path system, an ethanolamine gas analyzer, and a control system. Specifically, the high-temperature pretreatment gas path system includes process piping, flanges, sampling probes, high-temperature filters, heat tracing lines, heating boxes, drain filters, peristaltic pumps, three-way valve 1, three-way valve 2, orifice flow meters, vacuum pumps, gas outlets, molecular sieves, filters, zero gas, and standard gas. The ethanolamine gas analyzer includes a xenon lamp, a gas chamber, and a spectrometer. The control system includes a display screen and a gas analysis control unit.

[0039] Specifically, the sample gas in the process pipeline is sampled via a sampling probe mounted on a flange. The sampling probe contains a built-in high-temperature filter for primary filtration of the sample gas. The sample gas is then transported to the main unit via a heated pipeline. The main unit is equipped with a heating box. After entering the heating box, the sample gas first passes through a drain filter to separate the sample gas from the liquid water, which is then discharged by a peristaltic pump. After drying, the sample gas enters the gas chamber through electromagnetic three-way valves 1 and 2 (where electromagnetic three-way valves 1 and 2 select system functions through state switching and combination), and undergoes optical detection within the gas chamber. After detection, the sample gas flow is regulated and controlled by an orifice plate flow meter, and the sample gas is powered by a vacuum pump and discharged to the outlet.

[0040] The xenon lamp serves as the light source in the UV-DOAS, generating ultraviolet light. The ultraviolet light is introduced into the gas chamber through an optical fiber and is absorbed by the pretreated sample gas in the gas chamber. The emitted light after passing through the gas chamber is decomposed into different wavelengths by a spectrometer, and the intensity of specific absorption lines in the spectrum is measured.

[0041] The display screen enables human-computer interaction functions such as data display and operation; the gas analysis control unit performs functions such as pretreatment control, data analysis and processing, display and alarm, and function modes. Among them, the pretreatment control function mainly realizes the control of heating temperature and the start and stop control of the gas pump to ensure that the sample gas can be transmitted without condensation and component loss; the data processing, display and alarm functions mainly realize the concentration inversion and calculation of ultraviolet differential method, data display and storage, and over-limit alarm.

[0042] The system mode selection function allows for the selection and switching of measurement, zeroing, and calibration functions, combined with... Figure 2 The flow control logic diagram illustrates the function switching process.

[0043] After passing through the probe, the sample gas is transmitted to the main unit via an electrically heated pipeline and undergoes water vapor separation through a drain filter. When the system is in normal measurement mode, the sample gas enters the high-temperature gas chamber through three-way valve 1 (which is de-energized at this time) and three-way valve 2 (which is de-energized at this time), and the concentration of ethanolamine is monitored through the ultraviolet differential optics principle. After the detection is completed, the sample gas is vented through a flow meter and a sampling pump. When the system is in zero-adjustment mode, ambient air is used as the zero gas. Air passes through a molecular sieve and filter to remove particulate matter and moisture from the ambient air. Clean air then passes through three-way valve 1 (which is energized) and three-way valve 2 (which is de-energized) to reach the high-temperature gas chamber. Once the gas chamber is filled with zero gas, the zeroing function can be achieved in conjunction with the control system. When the system is in calibration mode, an external standard gas cylinder needs to be connected. The standard gas passes through three-way valve 2 (which is energized, and three-way valve 1 is de-energized to prevent sample gas backflow) to reach the high-temperature gas chamber. Once the gas chamber is filled with standard gas, the system calibration function can be achieved in conjunction with the control system.

[0044] In summary, this utility model system integrates sample gas pretreatment, concentration analysis and detection, and system calibration functions, enabling quantitative analysis and alarm functions for volatile organic amine gases in a carbon dioxide capture system. Compared to chromatographic systems, which are complex (e.g., separation systems), have long detection cycles (minute-level), require consumables (e.g., chromatographic columns), and cannot achieve automated measurement (requiring manual sampling), this utility model system adopts a modular design, making it simple, reliable, and fully functional. It also features high measurement accuracy, good reliability, convenient maintenance, and strong anti-interference capabilities, enabling rapid and accurate detection of ethanolamine gas leakage and escape in carbon dioxide capture devices. The system integrates sampling and transmission, data processing and analysis, and display and alarm functions. The gas path in the system is kept at a constant high temperature with heating, effectively eliminating interference from condensate and improving measurement stability and accuracy. Furthermore, the system features automatic zeroing and automatic calibration functions.

[0045] The online detection method for volatile organic amine gases based on this invention specifically replaces the existing chromatographic method with a combination of thermal wet method and ultraviolet differential optical method, enabling automatic and continuous measurement of ethanolamine gas. The method includes the following steps:

[0046] Step 1, High-temperature sampling and transmission: Extract waste gas sample from the carbon capture outlet / desorption tower outlet pipeline; transmit the sample gas at a constant temperature through a fully heated pipeline to prevent water vapor condensation and component loss; preliminarily remove particulate matter through a sampling probe with a built-in high-temperature filter;

[0047] Step 2, dynamic dehydration pretreatment: After the sample gas enters the heating box, it is separated into gas and liquid by a drain filter; the separated liquid water is automatically discharged by a peristaltic pump to ensure that the gas entering the detection unit is dry.

[0048] Step 3, Intelligent switching of detection modes:

[0049] Measurement mode: The three-way valve group is switched to the sample gas passage (valve 1 / valve 2 is de-energized); the dried sample gas enters the high-temperature gas chamber for optical detection.

[0050] Automatic zeroing mode: The three-way valve group switches to the zero gas passage (valve 1 is powered on, valve 2 is powered off); ambient air is purified by molecular sieve + filter and then introduced into the gas chamber to complete baseline calibration.

[0051] Automatic calibration mode: The three-way valve group switches to the calibration gas passage (valve 2 is energized, valve 1 is de-energized to prevent backflow); the calibration gas in the standard gas cylinder is introduced into the gas chamber to complete the concentration calibration.

[0052] Step 4, UV-DOAS Concentration Detection: A xenon lamp emits ultraviolet light, which is guided into the gas chamber via an optical fiber; the ethanolamine in the sample gas absorbs characteristic ultraviolet light (200–230 nm); the spectrometer analyzes the emitted light and uses a differential absorption algorithm (…). Figure 3 Background noise is removed, and the concentration of ethanolamine is retrieved in real time.

[0053] Step 5, Data Processing and Alarm: The gas analysis and control unit performs concentration calculation (based on the intensity of characteristic absorption peaks); data is stored and displayed in real time; if the concentration exceeds the limit, an alarm is triggered immediately.

[0054] Step 6, Sample gas discharge: The gas after detection is discharged by a vacuum pump after the flow rate is adjusted by an orifice plate flow meter.

[0055] In summary, the above are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An online detection system for volatile organic amine gases, characterized in that, include: High-temperature pretreatment gas path system: used to collect sample gas from the carbon capture outlet or desorption tower outlet pipeline, and to perform anti-condensation transmission and water removal treatment on the sample gas; Ethanolamine gas analyzer: Connected to the pretreatment gas path system, it detects the concentration of organic amines in the sample gas based on the UV-DOAS ultraviolet differential absorption principle; Control system: Connected to the pretreatment gas circuit system and the gas analyzer respectively, to realize sampling control, concentration calculation and alarm functions; The high-temperature pretreatment gas path system includes the following components connected in sequence: A sampling probe with a built-in high-temperature filter is used for primary filtration of particulate matter; Thermostatic heating pipeline is used to maintain the sample gas temperature at 180–200℃; A drain filter and peristaltic pump are used to achieve gas-liquid separation and automatically discharge liquid water; The valve group, consisting of three-way valve 1 and three-way valve 2, is used to switch between measurement, zeroing, and calibration modes; The ethanolamine gas analyzer includes: Xenon lamp light source, gas chamber and spectrometer, used for differential absorption spectroscopy analysis in the 200–230 nm wavelength range.

2. The system according to claim 1, characterized in that, The operating modes of the valve assembly include: Measurement mode: Three-way valve 1 and three-way valve 2 are de-energized, and the sample gas flows directly into the gas chamber; Zeroing mode: Three-way valve 1 is energized, three-way valve 2 is de-energized, and ambient air is introduced into the air chamber after being purified by molecular sieve and filter; Calibration mode: Three-way valve 2 is energized and three-way valve 1 is de-energized, the calibration gas enters the gas chamber and the backflow of the sample gas is blocked.

3. The system according to claim 1 or 2, characterized in that, The drain filter is located inside the heating box and discharges the separated liquid water in real time via a peristaltic pump.

4. The system according to claim 1 or 2, characterized in that, The control system includes: The gas analysis and control unit is used to perform heat tracing temperature control, start and stop of the gas pump, concentration inversion and alarm for exceeding the limit; The display screen is used to show concentration data and alarm information in real time.

5. The system according to claim 4, characterized in that, The pretreatment gas path system also includes: An orifice plate flow meter, located at the outlet of the gas chamber, is used to regulate the sample gas flow rate; An air pump provides the power for sampling and vents the gas after detection.

6. The system according to claim 2, characterized in that, The zero-adjustment mode uses ambient air that has been filtered through a molecular sieve to adsorb moisture and particulate matter as zero air.

7. The system according to claim 1, 2 or 6, characterized in that, The spectrometer receives the light emitted from the gas cell via optical fiber and analyzes the characteristic absorption spectrum of ethanolamine in the 200–230 nm wavelength range.

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