Absorption type gas analysis system and method

Abstract

The invention relates to an absorption type gas analysis system and method.The system comprises a gas conveying system, an absorption liquid conveying system and a micro-mixing system, the gas conveying system and the absorption liquid conveying system enter the micro-mixing system through a three-way pipe, gas and absorption liquid are mixed and absorbed in the micro-mixing system, and after gas-liquid separation, the absorption liquid enters the micro-mixing system; and gas and liquid are respectively discharged. The method comprises the steps that pressurized and metered absorption liquid and gas jointly enter the micro-mixer to be fully mixed, then the mixture enters the micro-channel absorber to be fully contacted and absorbed, after the mixture passes through the gas-liquid separator, the gas obtained after liquid separation is treated and then reaches the standard to be discharged, and the absorption liquid obtained after gas separation is sampled to analyze target substances or elements. The gas-liquid mixing is sufficient, the concentration gradient is obviously increased, the mass transfer distance is obviously reduced, and rapid and sufficient absorption is realized, so that the mass transfer efficiency is improved, and the detection precision and speed are further improved.

Description

Technical Field

[0001] The present invention relates to an absorption gas analysis system and method, belonging to the technical field of micro-chemical engineering. Background Art

[0002] The analysis of gas mixtures and the qualitative and quantitative determination of the content of each gaseous substance have great practical significance in many industrial sectors. In the control and regulation of production processes that handle various gases, as well as production processes that emit or absorb gases, especially in environmental protection, the monitoring and analysis of waste gas emissions and harmful substances in the atmosphere widely apply gas analysis. Although currently pure physical methods are widely used and automatic and semi-automatic gas analyzers are also in use, until now, the macro analysis of gases still mainly relies on chemical analysis methods.

[0003] As one of the commonly used chemical analysis methods, the solution absorption method is a method for collecting gaseous, vaporous sample components and certain aerosols in gases with an absorption liquid. Its basic principle is that when a gas sample passes through the absorption liquid, the molecules of the substance to be measured in the gas enter the absorption liquid due to dissolution or chemical reaction. In the actual analysis process of this method, an absorption liquid that undergoes a chemical reaction with the substance to be measured is often used. Generally, the absorption rate is used to characterize the degree that the substance to be measured can reach through a specified device. However, when a gas dissolves in a liquid, there is often a heat effect, and when a chemical reaction occurs, there is also a reaction heat, and as a result, the temperature of the liquid phase gradually increases. Currently, the commonly used absorption methods such as washing bottles generally have disadvantages such as low absorption efficiency, the need for multi-stage series absorption, a large volume of gas samples required, a large absorption agent circulation volume, a long residence time, even severe foaming and entrainment, and high costs. This requires the absorber to have a large specific surface area and rapid heat dissipation to improve the absorption rate.

[0004] The patent with the publication number CN202661318U discloses a pre-heated ammonia absorption device for an ammonia method desulfurization flue gas emission monitoring and analysis mechanism. This patent can indeed achieve the chemical reaction of NH3 with SO2 and H2O to form sulfates in terms of chemical principles. However, under the conditions of this patent, it is very difficult to fully carry out the reaction. Because, affected by the gas flow rate and the pipe diameter, the formed bubbles are relatively large, in the millimeter to centimeter range. During the upward floating process of the bubbles, only the part of the bubble edge in contact with the absorption liquid can preferentially undergo a chemical reaction, and the NH3 molecules in the middle of the bubble cannot contact the absorption liquid due to mass transfer limitations and do not undergo a chemical reaction. Therefore, the reaction efficiency in this device is very low, the absorption effect is not ideal, and the error is relatively large.

[0005] The patent with the publication number CN217605438U discloses an efficient absorption device for flue gas component detection. Its core dispersion component is a perforated partition plate. Although the aperture is 1 - 2 mm, it cannot ensure that the diameter of the steam drum passing through the small holes is 1 - 2 mm, and the bubble volume is even more uncontrollable. Moreover, between the partition plates, bubble coalescence is inevitable, forming larger bubbles, thus weakening the dispersion and mixing effects of the partition plates. Therefore, there are also problems similar to those in the patent with the publication number CN202661318U, such as poor absorption effect.

[0006] The patent with the publication number CN210639118U discloses an on-line continuous monitoring device for hydrogen chloride in flue gas. However, this device uses a porous glass plate absorption bottle, and there are still problems such as insufficient absorption caused by too large bubbles. Moreover, in this patented technology, it takes 1 hour to test one sample, corresponding to the average concentration of HCl within 1 hour, and it cannot achieve rapid real-time measurement.

[0007] The patent with the publication number CN112147287B discloses an on-line measurement system and method for HCl in flue gas. However, this HCl absorber is a conventional packed tower. The absorption liquid is sprayed into the tower, the gas-liquid contact area is small, the contact time is short, and the absorption effect is poor. Moreover, the liquid holdup at the bottom of the tower is relatively large, and the absorption liquids at different time periods are mixed with each other, and there is no absorption liquid concentration strictly corresponding to the sampling time. Especially when the gas concentration changes suddenly, the change in the concentration of the absorption liquid cannot occur immediately but requires a certain time to reflect the true concentration of the measured gas. However, in various working conditions, especially for detections aimed at safety, rapid detection is often required. Therefore, there are still problems such as poor absorption effect and the inability to truly achieve real-time detection.

[0008] Microchemical technology is a cutting-edge chemical technology developed in recent years. It generally uses chemical equipment with microstructures manufactured through microfabrication technology and precision machining technology, and is a new chemical technology that studies the characteristics and laws of "three transfers and one reaction" at the micro time-space scale. Among them, equipment such as microchannel reactors, microchannel mixers, microchannel absorbers, microchannel separators, and microchannel heat exchangers are typical representatives. There is usually one or more microchannels inside the microchannel absorber, and the characteristic size of its channels is basically in the range of hundreds of micrometers, occasionally at the millimeter level. Due to the significant reduction in the channel size compared to traditional equipment, the concentration gradient and temperature gradient in the microchannels increase significantly, thus increasing the driving force for heat and mass transfer; on the other hand, with the reduction of the channel size, the specific surface area of the microchannel absorber increases, further enhancing the heat and mass transfer performance. In short, due to the short transfer distance, high concentration / temperature gradient, and large specific surface area of the system at the microscale, the heat / mass transfer coefficient in the microchannel absorber is 1 to 3 orders of magnitude larger than that of traditional chemical equipment, thus completing the absorption process quickly and efficiently. In addition, the microchannel absorber itself has a small liquid holdup, and the internal flow is a piston-flow laminar flow without backmixing. There is a relatively strict correspondence between the concentration of the absorption liquid and the absorption time (section), with good accuracy and precision, which can meet the requirements of rapid gas analysis.

[0009] In summary, the following problems mainly exist in the prior art:

[0010] 1. Due to the poor gas-liquid two-phase dispersion and low specific surface area, the absorption is insufficient, resulting in a large error in the analysis results.

[0011] 2. Limited by the transfer process, the gas sample flow rate is large, there is a problem of mutual mixing between different samples, with a large deviation, and the analysis time is long. Summary of the Invention

[0012] In order to solve the above existing problems, the present invention discloses an absorption-type gas analysis system and method, and its specific technical solutions are as follows:

[0013] An absorption-type gas analysis system includes a gas transmission system, an absorption liquid transmission system, and a micro-mixing system. The gas transmission system and the absorption liquid transmission system enter the micro-mixing system through a tee. The gas and the absorption liquid are mixed and absorbed in the mixing system. After gas-liquid separation, the gas and the liquid are discharged separately;

[0014] The gas transmission system is sequentially provided with a gas sampling tube (1), a fan (2), a gas check valve (3), a filter membrane (4) and its jacket, and a gas flow meter (5) from upstream to downstream according to the gas flow direction,

[0015] The absorption liquid transmission system is sequentially provided with an absorption liquid storage tank (8), an absorption liquid pump (9), an absorption liquid check valve (13), and an absorption liquid flow meter (12) from upstream to downstream according to the absorption liquid flow direction,

[0016] The micro-mixing system is sequentially provided with a micro-mixer (6), a micro-channel absorber (7), a back pressure valve (10), and a gas-liquid separator (11) from upstream to downstream. The outlet end of the gas-liquid separator (11) is connected to an exhaust gas discharge pipe (14) and an absorption liquid discharge pipe (15).

[0017] The downstream ends of the gas flowmeter (5) and the absorption liquid flowmeter (12) are connected to the micro-mixer (6) through a tee.

[0018] Further, the gas sampling pipe (1) is provided with heat tracing, and the heat tracing temperature is 15 °C higher than the gas source temperature or 20 °C higher than the dew point temperature of the condensable components in the gas under the analysis conditions.

[0019] Further, the filter membrane (4) is used to filter and intercept particulate matters in the gas, and the pore size is 0.3 - 3 μm.

[0020] Further, the blower (2) is used to extract and pressurize the gas in the gas sampling pipe (1) and transport it downstream. The outlet pressure of the blower (2) is 10 - 500 kPa.

[0021] Further, the micro-mixer (6) is used for sufficient pre-mixing of gas and liquid, and the micro-channel absorber (7) is used for sufficient contact, mixing and absorption of gas and liquid. The pore sizes of the micro-mixer (6) and the micro-channel absorber (7) are 5 - 1000 μm.

[0022] Further, the specific surface area of the fluid of the micro-channel absorber (7) is 10 4 ~10 6 m 2 / m 3 。

[0023] Further, the liquid holdup of the micro-channel absorber (7) is 0.01 - 20 mL.

[0024] Further, the micro-channel absorber (7) is a three-dimensional structure with uniformly spaced micro-channels.

[0025] Further, the lower vertex of the micro-channel absorber (7) is the feed point, and the upper vertex on the same body diagonal as the feed point is the discharge point. Moreover, each micro-channel is connected to at least three other branch micro-channels at the confluence point, resulting in multi-stage dispersion and mixing.

[0026] Based on the above absorption type gas analysis system, an absorption type gas analysis method includes the following steps:

[0027] Step 1: Set heat tracing on the gas sampling pipe (1) to prevent the condensable components in the gas from condensing and absorbing the target substances or elements.

[0028] Step 2: Under the pressure of the blower (2), the gas passes through the gas check valve (3) and then enters the filter membrane (4) and its jacket to remove the particulate matter carried therein, preventing blockage of subsequent equipment. The gas then passes through the gas flowmeter (5) and enters the tee.

[0029] Step 3: The absorption liquid pump (9) extracts the absorption liquid from the absorption liquid storage tank (8), pressurizes it through the absorption liquid check valve (13) and the absorption liquid flowmeter (12), and enters the tee.

[0030] Step 4: The pressurized and metered absorption liquid and gas enter the micro mixer together for full mixing, and then enter the microchannel absorber for full contact absorption. After passing through the gas-liquid separator, the gas after liquid separation is discharged up to standard after treatment, and the absorption liquid after gas separation is sampled and analyzed for target substances or elements.

[0031] The beneficial effects of the present invention are as follows:

[0032] In the present invention, the gas-liquid mixing is sufficient, the concentration gradient is significantly increased, and the mass transfer distance is significantly reduced, so that rapid and sufficient absorption can be achieved, thereby improving the mass transfer efficiency and further improving the detection accuracy and speed.

[0033] The absorption process flow and equipment structure design of the present invention are reasonable, easy to operate, and have strong applicability. By appropriately adjusting the equipment parameters, it can meet the gas analysis and detection requirements of different industries, different working conditions, and different compositions.

[0034] The present invention is a continuous flow absorption process without backmixing. There is a relatively strict corresponding relationship between the absorption liquid concentration and the absorption time (section), and on-line continuous detection can be realized. Description of the Drawings

[0035] Figure 1 is a schematic connection layout diagram of the present invention,

[0036] List of reference numerals: 1, gas sampling pipe; 2, blower; 3, gas check valve; 4, filter membrane; 5, gas flowmeter; 6, micro mixer; 7, microchannel absorber; 8, absorption liquid storage tank; 9, absorption liquid pump; 10, back pressure valve; 11, gas-liquid separator; 12, absorption liquid flowmeter; 13, absorption liquid check valve; 14, tail gas discharge pipe; 15, absorption liquid discharge pipe.

[0037] Figure 2 is a schematic structural diagram of the microchannel absorber of the present invention,

[0038] List of reference numerals: 16, gas inlet; 17, absorption liquid inlet; 18, discharge port. Detailed Embodiments

[0039] The present invention will be further illustrated below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0040] In conjunction with the attached Figure 1 As can be seen, the absorption gas analysis system of the present invention includes a gas sampling pipe 1 with tracing heat, a blower 2 for extracting gas and pressurizing, a filter membrane 4 for filtering particulate matter and its jacket, a gas flowmeter 5, an absorption liquid storage tank 8, an absorption liquid flowmeter 12, an absorption liquid pump 9, a gas check valve 3 placed after the blower 2, an absorption liquid check valve 13 placed after the absorption liquid pump 9, a micromixer 6 for full pre-mixing of gas and liquid, a microchannel absorber 7 for full contact, mixing and absorption of gas and liquid, a back pressure valve 10 for maintaining the absorption pressure, a gas-liquid separator 11, a tail gas discharge pipe 14, and an absorption liquid discharge pipe 15.

[0041] The specific process flow is as follows: Tracing heat is set on the gas sampling pipe 1 to prevent the condensable components in the gas from condensing and absorbing the target substances or elements; under the action of the blower 2, the gas enters the filter membrane 4 to remove the particulate matter carried therein to prevent clogging of subsequent equipment; then it enters the micromixer 6 together with the pressurized and metered absorption liquid for full mixing, and then enters the microchannel absorber 7 for full contact absorption. After passing through the gas-liquid separator 11, the waste gas after liquid separation is treated and discharged up to standard, and the absorption liquid after gas separation is sampled and analyzed for the target substances or elements.

[0042] The material of the gas sampling pipe 1 is stainless steel, plastic, latex, or polytetrafluoroethylene, preferably stainless steel and polytetrafluoroethylene. The tracing heat method of the gas sampling pipe is steam tracing heat, electric tracing heat, tracing pipe tracing heat, sleeve tracing heat, or jacket tracing heat, preferably steam or hot air jacket tracing heat. The tracing heat temperature of the gas sampling pipe is 15°C higher than the gas source temperature, or 20°C higher than the dew point temperature of the condensable components in the gas under the analysis conditions.

[0043] The pore size of the filter membrane 4 is 0.3 - 3 μm, preferably 0.5 - 1 μm. After the filter membrane, corresponding pretreatment modules can be set according to the characteristics of the gaseous impurities.

[0044] The tracing heat temperature of the gas sampling pipe 1 is 15°C higher than the gas source temperature, or 20°C higher than the dew point temperature of the condensable components in the gas under the analysis conditions, preferably 20°C higher than the dew point temperature of the condensable components in the gas under the analysis conditions.

[0045] The outlet pressure of the blower 2 is 10 - 500 kPa, preferably 50 - 300 kPa.

[0046] The outlet pressure of the absorption liquid pump 9 is the same as the outlet pressure of the blower;

[0047] The aperture of the micro mixer and the microchannel absorber is 5 - 1000 μm, preferably 100 - 500 μm;

[0048] The specific surface area of the fluid of the microchannel absorber is 10 4 - 10 6 m 2 / m 3 ,preferably 10 5 m 2 / m 3 ;

[0049] The liquid holdup of the microchannel absorber is 0.01 - 20 mL, preferably 0.5 - 10 mL;

[0050] By adjusting the flow rate of the blower and the flow rate of the absorbent liquid pump, the residence time of the gas and the absorbent liquid in the microreactor is adjusted to meet the analysis requirements of different gases and absorbent liquids.

[0051] Combined with the attached Figure 2 , Figure 2 In the figure, the gas and the absorbent liquid are introduced from a vertex at the bottom. The gas and the absorbent liquid enter the microchannel absorber simultaneously. During use, each branch microchannel (the connection line between any two points shown in the figure is a section of microchannel) will be filled with gas and absorbent liquid. Refer to the attached Figure 2 In the figure, the absorbent liquid and the gas are connected to at least three other branch microchannels at any confluence point, resulting in multi-stage dispersion and mixing. Moreover, the total length of all microchannels connecting the feed point and the discharge point is the same. Due to the very small aperture of the microchannels (usually several hundred micrometers), the absorbent liquid fills the microchannels, and the gas is repeatedly squeezed and sheared in the microchannels, being fully mixed with the absorbent liquid, thereby achieving the full absorption of the target gas components. The confluence point of each section of microchannel is the mixing point where the gas and the absorbent liquid come out from a section of microchannel. After the gas and the absorbent liquid enter the mixing point, they enter at least three branch microchannels again, repeating this process in turn, and finally converging to the discharge port to leave the microchannel absorber. The structural design of the microchannel absorber of the present invention can force the gas into the interior of the absorbent liquid, and the path of the microchannel is relatively long. After each confluence point, the gas and the absorbent liquid are mixed multi-stage in different sections of the microchannel, improving the absorption efficiency and uniformity.

[0052] Figure 2 This is a schematic diagram of a unit structure of the microchannel absorber of the present invention. In actual use, according to specific working conditions such as the gas volume or the gas absorption coefficient, several unit structures are connected in series (parallel) in its length, height, and / or width directions (that is, Figure 2 the discharge point 18 shown in the figure is connected to the feed point of the next unit), to extend the microchannels of the microchannel absorber. Figure 2The gas inlet 16 and the absorbent liquid inlet 17 enter simultaneously at a vertex of the unit structure. The gas and the absorbent liquid are mixed in the microchannels of the three-dimensional structure and discharged from the opposite vertex in three dimensions, that is, the feed port formed by the gas inlet and the absorbent liquid inlet and the discharge port are on the same body diagonal line.

[0053] The following are several embodiments of the present invention in specific applications:

[0054] Embodiment 1

[0055] Detection of hydrogen chloride in the waste gas from stationary pollution sources. The waste gas passes through the gas sampling pipe 1 with 120°C heat tracing, is pressurized to 100 kPa by the fan 2, and passes through the filter membrane 4 at a flow rate of 20 mL / min to remove particulate matter in the waste gas; the sodium carbonate absorbent solution with a concentration of 30 mmol / L is pressurized by the absorbent liquid pump 9 at a flow rate of 6 ml / min; subsequently, the two enter the micro-mixer 6 through a T-shaped tee for sufficient mixing, and then enter the micro-channel absorber 7 to continue absorbing hydrogen chloride gas in the waste gas, and then enter the gas-liquid separator 11. The waste gas after separating the liquid is discharged up to standard after treatment, and the absorbent liquid after separating the gas is analyzed for the chloride ion content. After the gas-liquid flow rate is stable, the absorbent liquid at 0.5 min, 1 min, 1.5 min, and 2 min is taken for analysis respectively. The detection result of the hydrogen chloride content in the waste gas is 36.015 mg / m 3 、35.412 mg / m 3 、36.138 mg / m 3 、35.247 mg / m 3 。For comparison, the "Determination of hydrogen chloride in waste gas from stationary pollution sources - Silver nitrate volumetric method (HJ 548 - 2016)" is used for analysis at the same time. After absorbing for 1 h, the detection result of the hydrogen chloride content in the waste gas is 35.671 mg / m 3 。It can be seen that under the condition of the same hydrogen chloride absorption amount, the absorption time of this patent is shorter and more efficient.

[0056] Embodiment 2

[0057] Detection of sulfur dioxide in the exhaust gas from stationary pollution sources. The exhaust gas passes through the gas sampling pipe 1 with 150°C heat tracing, is pressurized to 80 kPa by the fan 2, and passes through the filter membrane 4 at a flow rate of 50 mL / min to remove particulate matter in the exhaust gas; the sodium carbonate absorption solution with a concentration of 30 mmol / L is pressurized by the absorption liquid pump 9 at a flow rate of 5 ml / min; subsequently, the two enter the micro mixer 6 through a Y-shaped tee for full mixing, then enter the microchannel absorber 7 to continue absorbing SO2 gas in the exhaust gas, and then enter the micro gas-liquid separator 11. The exhaust gas after liquid separation is treated and discharged up to standard, and the absorption liquid after gas separation is analyzed to calculate the sulfur dioxide content in the exhaust gas. After the gas-liquid flow rate is stable, the absorption liquids at 0.5 min, 1 min, 1.5 min, and 2 min are taken for analysis respectively, and the detection results of the sulfur dioxide content in the exhaust gas are 1000.23 mg / m 3 、1012.37 mg / m 3 、998.49 mg / m 3 、1007.62 mg / m 3 。For comparison, the "Iodometric Method for the Determination of Sulfur Dioxide in Exhaust Gas from Stationary Pollution Sources (HJ / T 56-2000)" is simultaneously used for analysis. After 30 minutes of absorption, the detection result of the sulfur dioxide content in the exhaust gas is 1003.55 mg / m 3 。It can be seen that under the condition of the same sulfur dioxide absorption amount, the absorption time of this patent is shorter and more efficient.

[0058] Example 3

[0059] Detection of ammonia content in coke oven gas. The coke oven gas passes through the gas sampling pipe 1 with 130°C heat tracing, is pressurized to 50 kPa by the fan 2, and passes through the filter membrane 4 at a flow rate of 50 mL / min in sequence to remove particulate matter in the coke oven gas. The sulfuric acid absorption solution with a concentration of 0.1 mol / L is pressurized by the absorption liquid pump at a flow rate of 5 ml / min; subsequently, the two enter the micro mixer 6 through a Y-shaped tee for full mixing, then enter the microchannel absorber 7 to continue absorbing ammonia in the exhaust gas, and then enter the micro gas-liquid separator 11. The coke oven gas after liquid separation is treated and discharged up to standard, and the absorption liquid after gas separation is analyzed to calculate the ammonia content in the exhaust gas. After the gas-liquid flow rate is stable, the absorption liquids at 0.5 min, 1 min, 1.5 min, and 2 min are taken for analysis respectively, and the detection results of the ammonia content in the exhaust gas are 20.05 mg / m 3 、19.75 mg / m 3 、20.11 mg / m 3 、20.38 mg / m 3。For comparison, the "Determination Method for Components and Impurity Contents of Artificial Coal Gas (GB / T 12208 - 2008)" was used for analysis simultaneously. After 90 minutes of absorption, the detected ammonia content in the coke oven gas was 20.25 mg / m 3 。It can be seen that under the condition of the same ammonia absorption amount, the absorption time of this patent is shorter and more efficient.

[0060] Example 4

[0061] Detection of hydrogen sulfide content in coke oven gas. The coke oven gas passes through the gas sampling pipe 1 with 130°C heat tracing, is pressurized to 50 kPa by the fan 2, and sequentially passes through the filter membrane 4 at a flow rate of 50 mL / min to remove particulate matter in the coke oven gas; the zinc ammonia complex solution as the absorption liquid is pressurized by the absorption liquid pump 9 at a flow rate of 6 ml / min; subsequently, the two enter the micro - mixer 6 through a T - shaped tee for sufficient mixing, then enter the micro - channel absorber 7 to continue absorbing hydrogen sulfide in the waste gas, and then enter the micro - gas - liquid separator 11. The coke oven gas after separating the liquid is treated to meet the discharge standards, and the absorption liquid after separating the gas is analyzed to calculate the hydrogen sulfide content in the waste gas. After the gas - liquid flow rate is stable, the absorption liquid at 0.5 min, 1 min, 1.5 min, and 2 min is taken for analysis respectively, and the detected hydrogen sulfide content in the waste gas is 25.31 mg / m 3 、24.96 mg / m 3 、25.11 mg / m 3 、25.38 mg / m 3 。For comparison, the "Determination Method for Components and Impurity Contents of Artificial Coal Gas (GB / T12208 - 2008)" was used for analysis simultaneously. After 80 minutes of absorption, the detected hydrogen sulfide content in the coke oven gas was 25.86 mg / m 3 。It can be seen that under the condition of the same hydrogen sulfide absorption amount, the absorption time of this patent is shorter and more efficient.

[0062] Example 5

[0063] Detection of fluoride in the waste gas from stationary pollution sources. The waste gas passes through the gas sampling pipe 1 with 150 °C heat tracing, is pressurized to 20 kPa by the fan 2, and passes through the filter membrane 4 at a flow rate of 20 mL / min in sequence to remove the particulate matter in the waste gas; the 30 mmol / L sodium hydroxide absorbent is pressurized by the absorbent pump 9 at a flow rate of 5 ml / min; subsequently, the two enter the micro mixer 6 through a T-shaped tee for sufficient mixing, then enter the microchannel absorber 7 to continue absorbing the fluoride in the waste gas, and then enter the micro gas-liquid separator 11. The waste gas after separating the liquid is treated to meet the discharge standards, and the absorbent after separating the gas and the particulate matter on the filter membrane 4 are analyzed respectively to calculate the fluoride content in the waste gas. After the gas-liquid flow rate is stable, the absorbents at 0.5 min, 1 min, 1.5 min, and 2 min are taken for analysis respectively, and the detection results of the amide compound content in the waste gas are 130.25 mg / m 3 、129.93 mg / m 3 、130.02 mg / m 3 、129.86 mg / m 3 。For comparison, the "Ion Selective Electrode Method for the Determination of Fluoride in Stationary Pollution Sources of the Atmosphere (HJ / T 67-2001)" is used for analysis at the same time. After absorbing for 20 min, the detection result of the amide compound content in the coke oven gas is 130.22 mg / m 3 。It can be seen that under the condition of the same fluoride absorption amount, the absorption time of this patent is shorter and more efficient.

[0064] Those skilled in the art of this technology can understand that unless otherwise defined, all terms (including technical terms and scientific terms) used here have the same meaning as the general understanding of those of ordinary skill in the art in the field to which this application belongs. It should also be understood that those terms defined in general dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as here.

[0065] Taking the above-mentioned ideal embodiments of the present invention as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An absorption gas analysis system, characterized in that, It includes a gas transfer system, an absorbent liquid transfer system and a micro-mixing system. The gas transfer system and the absorbent liquid transfer system enter the micro-mixing system through a tee. The gas and the absorbent liquid are mixed and absorbed in the micro-mixing system. After gas-liquid separation, the gas and the liquid are discharged separately. The gas transfer system is sequentially provided with a gas sampling pipe (1), a fan (2), a gas check valve (3), a filter membrane (4) and its jacket, and a gas flowmeter (5) from upstream to downstream according to the gas flow direction. The absorbent liquid transfer system is sequentially provided with an absorbent liquid storage tank (8), an absorbent liquid pump (9), an absorbent liquid check valve (13) and an absorbent liquid flowmeter (12) from upstream to downstream according to the absorbent liquid flow direction. The micro-mixing system is sequentially provided with a micro-mixer (6), a micro-channel absorber (7), a back pressure valve (10), and a gas-liquid separator (11) from upstream to downstream. The outlet end of the gas-liquid separator (11) is connected to a tail gas discharge pipe (14) and an absorbent liquid discharge pipe (15). The downstream ends of the gas flowmeter (5) and the absorbent liquid flowmeter (12) are connected to the micro-mixer (6) through a tee.

2. The absorption type gas analysis system according to claim 1, characterized in that, The gas sampling pipe (1) is provided with heat tracing, and the heat tracing temperature is 15°C higher than the gas source temperature or 20°C higher than the dew point temperature of the easily condensable components in the gas under the analysis condition.

3. The absorption type gas analysis system according to claim 1, characterized in that, The filter membrane (4) is used to filter and intercept particulate matter in the gas, and the pore size is 0.3 - 3 μm.

4. The absorption-type gas analysis system according to claim 1, characterized in that, The fan (2) is used to extract the gas in the gas sampling pipe (1) and pressurize it, and transport it downstream. The outlet pressure of the fan (2) is 10 - 500 kPa.

5. The absorption type gas analysis system according to claim 1, characterized in that The micro-mixer (6) is used for sufficient pre-mixing of gas and liquid, and the micro-channel absorber (7) is used for sufficient contact, mixing and absorption of gas and liquid. The pore sizes of the micro-mixer (6) and the micro-channel absorber (7) are 5 - 1000 μm.

6. The absorption-type gas analysis system according to claim 1, characterized in that, The specific surface area of the fluid of the microchannel absorber (7) is 10 4 ~10 6 m 2 / m 3 。 7. The absorption gas analysis system according to claim 1, wherein, The liquid holdup of the micro-channel absorber (7) is 0.01 - 20 mL.

8. The absorption type gas analysis system according to claim 1, characterized in that, The micro-channel absorber (7) is a three-dimensional structure with uniformly spaced micro-channels.

9. The absorption-type gas analysis system according to claim 8, wherein, The lower vertex of the micro-channel absorber (7) is the feed point, and the upper vertex on the same body diagonal as the feed point is the discharge point.

10. The absorption gas analysis method of the absorption gas analysis system according to any one of claims 1-9, characterized in that, It includes the following steps: Step 1: Set heat tracing on the gas sampling pipe (1) to prevent the easily condensable components in the gas from condensing and absorbing the target substances or elements. Step 2: Under the pressurization of the fan (2), the gas enters the filter membrane (4) and its jacket through the gas check valve (3) to remove the particulate matter carried therein, preventing blockage of subsequent equipment. The gas then passes through the gas flowmeter (5) and enters the tee. Step 3: The absorbent liquid pump (9) extracts the absorbent liquid from the absorbent liquid storage tank (8), pressurizes it and passes through the absorbent liquid check valve (13) and the absorbent liquid flowmeter (12), and enters the tee. Step 4: The pressurized and metered absorbent liquid and gas enter the micro-mixer for sufficient mixing, and then enter the micro-channel absorber for sufficient contact absorption. After passing through the gas-liquid separator, the gas after liquid separation is discharged up to standard after treatment, and the absorbent liquid after gas separation is sampled to analyze the target substances or elements.

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