CN114609280A - Achieving low concentration of COxFID device and method for methanation conversion and detection - Google Patents

Achieving low concentration of COxFID device and method for methanation conversion and detection Download PDF

Info

Publication number
CN114609280A
CN114609280A CN202210255876.5A CN202210255876A CN114609280A CN 114609280 A CN114609280 A CN 114609280A CN 202210255876 A CN202210255876 A CN 202210255876A CN 114609280 A CN114609280 A CN 114609280A
Authority
CN
China
Prior art keywords
gas
nozzle
catalytic bed
middle section
channel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210255876.5A
Other languages
Chinese (zh)
Inventor
颜彬航
张智鹤
于子航
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua University
Original Assignee
Tsinghua University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsinghua University filed Critical Tsinghua University
Priority to CN202210255876.5A priority Critical patent/CN114609280A/en
Publication of CN114609280A publication Critical patent/CN114609280A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02—Column chromatography
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
    • C07C1/02—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon
    • C07C1/12—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon dioxide with hydrogen
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02—Column chromatography
    • G01N30/26—Conditioning of the fluid carrier; Flow patterns
    • G01N30/28—Control of physical parameters of the fluid carrier
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02—Column chromatography
    • G01N30/60—Construction of the column
    • G01N30/6004—Construction of the column end pieces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02—Column chromatography
    • G01N30/62—Detectors specially adapted therefor
    • G01N30/64—Electrical detectors
    • G01N30/68—Flame ionisation detectors

Abstract

The invention discloses a method for realizing low-concentration COxFID device and method that methanation shift and detect. The device comprises a nozzle shell, a nozzle inner channel, a catalytic bed layer, a quartz wool layer and a chromatographic column, wherein the nozzle inner channel penetrates through the nozzle shell along the height direction of the nozzle shell and comprises an upper section, a middle section and a lower section which are sequentially communicated from top to bottom, the inner diameter of the upper section is less than that of the middle section, the inner diameter of the lower section is less than that of the middle section, and the inner diameters of joints of the middle section and the upper section and the lower section are gradually changed from top to bottomLarge; the catalytic bed layer and the quartz wool layer are arranged in the middle section, and the Ni-based catalyst of the catalytic bed layer comprises metal Ni and metal oxide; the quartz cotton layer comprises an upper quartz cotton layer, a lower quartz cotton layer and a chromatographic column COxThe gas outlet end penetrates through the lower section of the inner channel of the nozzle and is stopped against the lower quartz cotton layer, and a gas channel is formed between the chromatographic column and the inner channel of the nozzle. The device can realize low-concentration CO without additional heating, temperature control and heat preservation equipment, a conversion chamber and a gas pipelinexThe detection is high in detection precision, accuracy and reliability.

Description

Achieving low concentration of COxMethanation conversionAnd detected FID device and method
Technical Field
The invention belongs to the field of detection and analysis, and particularly relates to low-concentration CO realizationxFID device and method that methanation conversion and detection.
Background
In scientific research and industrial production, low concentration CO is often requiredxThe detection is carried out by a common detector which is a gas chromatograph, but a TCD detector cannot generate signals for trace components, while an FID detector (namely a flame ionization detector) has high sensitivity, but can only detect ionized organic matters and COxNo response, therefore, the prior art detects trace CO by using FID detectorxThe CO is generally introduced by catalytic meansxReduction to CH4So that CO of ppm or less can be analyzedx。
A methane reforming furnace is commonly used as a generating device in the catalytic process, the appearance of the common reforming furnace is U-shaped or straight-tube type, a heating block and a temperature controller are adopted to respectively heat and control the temperature of the reforming furnace, the use temperature is 350-380 ℃, quartz wool and the like are adopted as heat insulation materials outside, and a hydrogenation pipeline needs to be additionally arranged to provide H required by methanation2On the basis that the structure of the methane reforming furnace is complex and the installation and maintenance are inconvenient, in recent years, various improved versions of methane reforming furnaces appear, such as methane reforming furnaces used for column heads of gas chromatographs, the device is provided with a heat preservation box, a heating chamber is arranged in the heat preservation box, the heating chamber is a reforming chamber, a catalytic tube adopts a vertical structure and can be directly connected with a chromatographic column in the chromatographic column chamber, the dead volume of airflow is greatly reduced, and the conversion efficiency is improved; in addition, there is a trace of CO for FID detectorsxAnalyzing gas chromatographic packed column, filling hydrogenation catalyst in one end of stainless steel chromatographic column tube, and adopting H2Can be used as carrier gas to realize trace COxAnalysis and detection. However, in various methane converters, the commonly used catalyst is a Ni-based supported catalyst, which can show higher activity at about 400 ℃, and the setting temperature of the FID detector is usually 200-350 ℃, which requires additional equipmentHeating, temperature control and heat preservation equipment is arranged outside the device.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, it is an object of the invention to propose achieving low concentrations of COxFID device and method that methanation conversion and detection. The device simply reforms transform through the shower nozzle to the FID detector, with methane reformer and FID detector integration in an organic whole, need not extra heating, accuse temperature and heat preservation equipment, also need not extra conversion room and gas pipeline and can realize the CO of low concentrationxThe detection not only reduces the energy consumption of equipment and the space of the device, directly enhances the multifunctional characteristic of the gas chromatography, but also has the advantages of high detection precision, high accuracy and good reliability, and has wide application prospect.
In one aspect of the invention, the invention provides a method for achieving low concentration of COxFID device for methanation conversion and detection. According to an embodiment of the invention, the apparatus comprises:
a nozzle housing;
the inner nozzle channel penetrates through the nozzle shell along the height direction of the nozzle shell and comprises an upper section, a middle section and a lower section which are sequentially communicated from top to bottom, the inner diameter of the upper section is smaller than that of the middle section, the inner diameter of the middle section is smaller than that of the lower section, the inner diameter of the joint of the upper section and the middle section is gradually increased from top to bottom, and the inner diameter of the joint of the middle section and the lower section is gradually increased from top to bottom;
the catalytic bed layer is arranged in the middle section of the nozzle inner channel and comprises a Ni-based catalyst, and the Ni-based catalyst comprises metal Ni and metal oxide;
the quartz cotton layer is arranged in the middle section of the inner channel of the nozzle and comprises an upper quartz cotton layer and a lower quartz cotton layer which are used for fixing the catalytic bed layer;
chromatography column of COxThe gas outlet end passes through the lower section of the inner channel of the nozzle and is stopped against the lower sectionAnd a gas channel is formed between the chromatographic column and the inner channel of the nozzle.
Present Low concentration CO of the above embodiments of the inventionxThe FID device for methanation conversion and detection is simply transformed by a spray head of the FID detector, and a Ni-based catalyst with high activity at low temperature (such as less than 350 ℃ or 250 ℃) is adopted, so that the temperature of the detector can provide heat for the methane conversion process, extra heating, temperature control and heat preservation equipment is not needed, an extra conversion chamber and a gas pipeline are not needed, the methane conversion furnace and the FID detector can be integrated into a whole, and low-concentration CO is carried at the momentxThe carrier gas may be contacted with H at the outlet of the column2(and tail gas blowing) are mixed and then pass through the catalytic bed layer section, and CO is finished at the set temperature (such as 200-350 ℃) of FID detectionxMethanation conversion and detection of (1), wherein, COxThe methanation conversion rate of (2) is high, for example, the conversion rate can be not less than 98%. To sum up, this FID device is integrated in an organic whole with methane reformer and FID detector, has both reduced equipment energy consumption and device space, has directly increased the multifunctional characteristic of strong gas chromatography, can also better realize the CO of low concentration (like 2 ~ 10000ppm) on the basis of not changing FID detector size and service conditionxThe method has the advantages of high detection precision, high accuracy and good reliability, and has wide application prospect.
In addition, according to the embodiments of the present invention, low concentration of CO is realizedxThe FID device for methanation conversion and detection may also have the following additional technical features:
in some embodiments of the invention, the upper portion of the nozzle housing is conical, pyramidal, intrados conical, or extrados conical.
In some embodiments of the present invention, the Ni-based catalyst has a content of the metal oxide of 10 to 60 wt%.
In some embodiments of the invention, the Ni-based catalyst comprises metallic Ni and a metal oxide support comprising a metal selected from Al2O3、SiO2、CeO2、La2O3、Eu2O3、ZrO2、Sm2O3And the mass ratio of the metal Ni to the metal oxide carrier is (40-90): (10-60).
In some embodiments of the present invention, the catalyst used in the catalyst bed layer has a particle size of 40 to 200 mesh.
In some embodiments of the invention, the thickness of the catalytic bed layer is 5-40 mm, and the thickness of the upper quartz cotton layer and the thickness of the lower quartz cotton layer are respectively and independently 0.5-3 mm.
In some embodiments of the invention, the chromatography column is a capillary column or a packed column.
In some embodiments of the invention, in the inner channel of the nozzle, the inner diameter of the upper section is 0.1-3 mm, and the length is 1-20 mm; the inner diameter of the middle section is 1-6 mm, and the length of the middle section is 6-30 mm; the inner diameter of the lower section is 2-10 mm, and the length of the lower section is 10-80 mm.
In some embodiments of the invention, the lower middle portion of the nozzle housing is removably attached to a base disposed below the nozzle housing.
In some embodiments of the invention, the nozzle housing is threadably connected to the base.
In some embodiments of the present invention, the nozzle housing further includes an insulating transition layer disposed above a connection position of the nozzle housing and the base and dividing the nozzle housing into two parts which are not connected up and down.
According to another aspect of the invention, the invention provides a FID device for realizing low-concentration CO by adopting the low-concentration COx methanation conversion and detectionxA methanation conversion and detection method. According to an embodiment of the invention, the method comprises:
(1) make CO carriedxThe gas to be detected flows out of the chromatographic column and enters the catalytic bed layer to enable H to flow out2Entering the catalytic bed layer from a gas channel;
(2) by CO in the gas to be detectedxAnd H2Reacting at the operating temperature of the catalytic bed and the FID detectorGenerating CH4And H2O；
(3) Gas, H, is carried by chromatographic column2And CH4Combining the catalytic bed layer and the catalyst layer into one path at the upper section of the inner channel of the nozzle, and allowing the path to flow out through the nozzle opening;
(4) h for letting air out over and in the nozzle openings2The hydrogen flame ionization region is formed by meeting, the hydrocarbon is ionized in the flame region to form positive ions, the positive ions are collected and moved under the action of a negative electrostatic field to form weak current, the weak current is amplified by an electrometer to form a detection signal, and the detected CH is obtained based on the detection signal4So as to calculate and obtain CO in the gas to be detectedxThe content value of (a).
The implementation of the above embodiment of the invention for low concentration COxThe methanation conversion and detection method can directly utilize the temperature of the detector to provide heat for the methanation conversion process, does not need additional heating, temperature control and heat preservation equipment, does not need additional conversion chambers and gas pipelines, and has the advantages of simple process, low energy consumption, COxThe methanation conversion rate is high (for example, the conversion rate can be not less than 98%), and the method has the advantages of high detection precision, high accuracy and good reliability, and can better realize low-concentration (for example, 2-10000 ppm) COxThe detection has wide application prospect.
In some embodiments of the invention, the component to be detected, CO, is separated from the sample gas using a chromatographic column prior to performing step (1)xAnd obtaining the gas to be detected.
In some embodiments of the present invention, in step (1), the carrier gas used in the chromatographic column is selected from the group consisting of high purity Ar, high purity He, and high purity N2And high purity H2At least one of (a).
In some embodiments of the present invention, in the step (1), the flow rate of the carrier gas is 2-50 ml/min, and H flows into the gas channel2The flow rate of (A) is 20-40 ml/min, H2The volume ratio of the carrier gas to the carrier gas is 0.4-50.
In some embodiments of the present invention, in step (1), the carrier gas has a flow rate of 2-50 ml/min, H2Flow rate of20 to 40ml/min, H2The volume ratio of the carrier gas to the carrier gas is 0.4-50.
In some embodiments of the invention, in step (1), H is reacted2And tail gas blowing enters the catalytic bed layer from a gas channel, wherein the flow of the tail gas blowing is 10-30 ml/min.
In some embodiments of the present invention, in the step (3), the flow rate of the air is 200 to 400 ml/min.
In some embodiments of the present invention, in the step (2), the operating temperature of the FID detector is 200-350 ℃.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic diagram of achieving low concentrations of CO according to one embodiment of the present inventionxAnd the structural schematic diagram of the FID device for methanation conversion and detection.
FIG. 2 is a top view of a lower section of a passageway in a nozzle in accordance with one embodiment of the present invention.
FIG. 3 is a diagram of achieving low concentrations of CO according to one embodiment of the present inventionxA flow chart of a methanation conversion and detection method.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
In the description of the present invention, it is to be understood that the terms "center", "length", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. In addition, in the present invention, unless otherwise explicitly specified or limited, terms such as "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. In addition, in the present invention, unless otherwise explicitly specified or limited, a first feature "on" or "under" a second feature may be directly contacted with the first and second features, or indirectly contacted with the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In one aspect of the invention, the invention provides a method for achieving low concentration of COxFID device for methanation conversion and detection. According to an embodiment of the invention, as understood with reference to fig. 1, the apparatus comprises: the nozzle comprises a nozzle shell 10, a nozzle inner channel 20, a catalytic bed layer 30, a quartz wool layer 40 and a chromatographic column 50. The device simply reforms transform through the shower nozzle to the FID detector, integrateed methane reformer and FID detector in an organic whole, need not extra heating, accuse temperature and heat preservation equipment, also need not extra conversion room and gas pipeline and can realize the CO of low concentrationxNot only reduces the energy consumption of the equipment and the space of the device, but also directly enhances the multifunction of the gas chromatographyThe method has the characteristics of high detection precision, high accuracy and good reliability, and has wide application prospect. The realization of low concentration CO according to the above embodiments of the present invention is described below with reference to FIGS. 1-2xThe FID device for methanation conversion and detection is described in detail.
Nozzle housing 10
According to the embodiment of the present invention, the upper structure of the nozzle housing 10 may be a cone, a pyramid, an intrados cone, an extrados cone, or the like, and the structure is more favorable for COxThe methane obtained by the reaction is mixed and combusted with air at the nozzle to realize CH pair by the FID detector4Detecting the content, and further indirectly obtaining CO in the gas to be detectedxThe content value of (a).
According to an embodiment of the present invention, the lower middle portion of the nozzle housing 10 may be detachably coupled with a base (not shown), which may be provided below the nozzle housing 10 for fixing the nozzle through the nozzle housing. It will be appreciated that the manner of connection of the nozzle housing 10 to the base is not particularly limited and may be selected by those skilled in the art according to the actual needs, as long as the nozzle housing is detachably fixed, for example, the nozzle housing 10 and the base may be connected by a screw thread.
According to the embodiment of the present invention, the material of the nozzle housing 10 is not particularly limited, and those skilled in the art can select the material according to actual needs, for example, the material of the nozzle housing 10 may be stainless steel, quartz, ceramic, platinum, or the like. Further, referring to fig. 2, it can be understood that when the nozzle housing 10 is not grounded and the nozzle is made of a metal material, the nozzle housing 10 may further include an insulating transition layer 70, where the insulating transition layer 70 may be disposed above the connection position 11 of the nozzle housing 10 and the base and divide the nozzle housing 10 into two parts that are not communicated (connected) up and down, so that the housing part near the nozzle opening and the housing part far away from the nozzle opening may be prevented from forming a conductive path.
Nozzle inner passage 20
According to an embodiment of the present application, as understood with reference to fig. 1, the nozzle inner passage 20 penetrates the nozzle housing 10 in a height direction of the nozzle housing 10, the nozzle inner passage20 including upper segment 21, middle section 22 and the hypomere 23 that from top to bottom communicates in proper order, the internal diameter of upper segment 21 is less than the internal diameter of middle section 22, and the internal diameter of middle section 22 is less than the internal diameter of hypomere 23, and the internal diameter of the junction 24 of upper segment 21 and middle section 22 from top to bottom grow gradually, and the internal diameter of the junction 25 of middle section 22 and hypomere 23 from top to bottom grows gradually. The inventor finds that by adopting the inner channel of the nozzle which is gradually narrowed from bottom to top, the fluidity of the air flow is better, the dead zone at the joint of two adjacent sections of the air flow is avoided, and the installation of the catalytic bed layer is facilitated, so that the operation is convenient, and the problems that the detected methane content is inaccurate due to the fact that the air flow stays in the dead zone (the staying amount is unknown) and the detection accuracy and reliability are influenced are solved. The lower section 23 of the nozzle inner passage 20 is used for supplying CO separated by the gas chromatography columnxIn which CO isxCan be carried into the channel in the nozzle by carrier gas and/or tail gas blowing; the middle section 22 is used for COxMethanation; the upper section 21 is used for supplying the methanation product to the nozzle mouth to be mixed with air for combustion.
According to the embodiment of the application, in the nozzle inner channel 20, the inner diameter of the upper section 21 may be 0.1-3 mm (for example, 0.5mm, 1mm, 2mm, or 3mm, etc.), and the length may be 1-20 mm (for example, 4mm, 8mm, 12mm, or 16mm, etc.); the middle section 22 may have an inner diameter of 1 to 6mm (e.g., 2mm, 3mm, 4mm, or 5 mm), and a length of 6 to 30mm (e.g., 10mm, 14mm, 18mm, 22mm, or 26 mm); the lower section 23 may have an inner diameter of 2 to 10mm (e.g., 4mm, 6mm, or 8 mm), and a length of 10 to 80mm (e.g., 20mm, 30mm, 40mm, 50mm, 60mm, or 70 mm), as long as the inner diameter of the upper section 21 < the inner diameter of the middle section 22 < the inner diameter of the lower section 23 are satisfied; in addition, compared with the lower section 23, the length of the middle section 22 and the upper section 21 has larger influence on the detection result, and the length of the middle section 22 can be combined with the type, efficiency and service life of the catalyst and the CO introduced into the gas to be detectedxThe concentration of (2), the fixing effect of the quartz wool layer on the catalyst, the inner diameter of the middle section, etc. can be flexibly selected, for example, the length of the upper section 21 < the length of the middle section 22 < the length of the lower section 23 can be made, so that not only can the orientation of the air flow be realizedHas better fluidity, and can be used for separating CO by gas chromatographic columnxAnd COxAnd H2Provides sufficient time to ensure as much CO as possiblexCan be converted into CH4Therefore, the accuracy and the reliability of the detection result can be further improved.
According to the embodiment of the present application, the nozzle inner passage 20 may be formed by a hollow nozzle casing body, or may be formed by a separate pipe inserted and fixed in the middle of the nozzle casing, wherein when the nozzle inner passage 20 is a separate pipe, the material thereof may be selected to be the same as or different from that of the nozzle casing 10, and specifically may be selected from stainless steel, quartz, ceramic, platinum, or the like. Preferably, the material of the nozzle inner channel 20 may be the same as the material of the nozzle housing 10, thereby being more beneficial to realize the heat transfer of the nozzle housing to the nozzle inner channel, enabling the catalyst to have higher catalytic activity at the working temperature of the FID detector, and realizing COxThe methanation is sufficient, the accuracy and the reliability of a detection result are improved, the consistency of thermal expansion coefficients of the inner channel of the nozzle and the shell of the nozzle is favorably kept, and the structural stability of the inner channel of the nozzle and the structural stability of the shell of the nozzle in the using process are better.
Catalytic bed 30
In accordance with embodiments of the present application, it is understood with reference to fig. 1 that a catalyst bed 30 is provided within the intermediate section 22 of the nozzle internal passage 20, the catalyst bed 30 comprising a Ni-based catalyst comprising a metal oxide. The inventor finds that the commonly used Ni-based supported catalyst can show higher activity generally at about 400 ℃, a methane converter needs to be additionally arranged, the working temperature needs to be set at 380-450 ℃, namely the methane converter needs heating, temperature control and heat preservation equipment to realize COxConversion to methane. And choose for use neotype Ni base catalyst, it can obtain higher catalytic activity and methane's selectivity under lower temperature (if < 350 ℃ or 250 ℃), from this, form the catalytic bed layer through adopting this catalyst, need not extra heating, accuse temperature and heat preservation equipment, only need simply reform transform the shower nozzle of FID detector, can utilize the temperature of detector itself to provide the heat for methane conversion process, realize COxThe methane is fully methanated, so that the original methane converter is abandoned, and the energy consumption of equipment and the space of the device are effectively reduced on the premise of ensuring the accuracy and the reliability of a detection result. .
According to an embodiment of the present application, the content of the metal oxide in the Ni-based catalyst may be 10 to 60 wt%, for example, may be 25 wt%, 35 wt%, or 45 wt%, etc. The inventor finds that if the content of the metal oxide is too low, the catalytic activity of the Ni-based catalyst at the working temperature of the FID detector is still not ideal, and if the content of the metal oxide is too high, the cost of the catalyst is obviously increasedxThe hydromethanation reaction of (A) can realize more than 98% of CO within the temperature range of 200-350 DEG CxConversion and 100% CH4Selectivity and good catalytic stability.
According to the embodiment of the application, the Ni-based catalyst adopted by the invention is a supported catalyst and comprises active metal Ni and a metal oxide carrier, wherein the metal oxide carrier can comprise Al2O3、SiO2、CeO2、La2O3、Eu2O3、ZrO2、Sm2O3And the mass ratio of the active metal Ni to the metal oxide support may be (40-90): (10 to 60) may be 45/55, 40/60 or 50/50, for example, and the active metal content of the Ni-based catalyst may be 40 to 90 wt%. It is understood that the support may comprise at least one metal oxide. The inventor finds that the metal oxide carrier and the active metal Ni have stronger interaction, and can realize the uniform dispersion of the active metal Ni on the carrier, thereby being more beneficial to improving the catalytic activity and the catalytic stability of the Ni-based catalyst; in addition, by controlling the mass ratio of the active metal Ni to the metal oxide to be in the above range, it is more advantageous to ensure the catalytic activity and methane selectivity of the Ni-based catalyst.
According to the applicationIn the embodiment, the particle size of the catalyst used in the catalyst bed layer 30 may be 40 to 200 mesh, for example, 40 to 50 mesh, 50 to 60 mesh, 80 to 100 mesh or 100 to 120 mesh, and the inventors found that by controlling the catalyst in the above understanding range, not only the granulation is more facilitated, but also the catalyst bed layer can have a suitable compaction density, so that not only CO can be made to have a suitable compaction densityxAnd H2Can have enough contact reaction time in the catalytic bed layer to realize COxSufficient methanation, effective passing through of air current can also be realized, make reaction gas can flow smoothly to nozzle mouth department and air mixed combustion, and then can utilize the FID detector to CH in combustion process4Detecting the content of the CO in the gas to be detected, and indirectly obtaining the CO in the gas to be detectedxThe content value of (a).
According to the embodiment of the application, the thickness of the catalyst bed layer 30 may be 5-40 mm, such as 8mm, 10mm, 15mm, 25mm or 35mm, and the inventor found that if the thickness of the catalyst bed layer is too small, it is difficult to ensure COxThe full methanation is realized in the process of flowing through the catalytic bed layer, if the thickness of the catalytic bed layer is too large, the retention time of air flow in the catalytic bed layer is too long, the detection efficiency is influenced, meanwhile, the raw material cost is increased, and based on the selection of the catalyst, the particle size and the inner diameter and the length of a channel in a nozzle, the thickness range of the catalytic bed layer is controlled, so that the CO can be ensuredxThe detection efficiency is improved and the raw material cost is reduced on the basis of full methanation (the conversion rate is more than 98%), and the high accuracy and reliability of the detection result are realized.
A layer of quartz wool 40
According to an embodiment of the present invention, as will be understood with reference to fig. 1, a layer of quartz wool 40 is provided in the middle section 22 of the nozzle inner passage 20, the layer of quartz wool 40 comprising an upper layer 41 of quartz wool and a lower layer 42 of quartz wool for fixing the catalyst bed 30, whereby the penetration of the gas flow is not affected and an effective fixing of the catalyst bed is achieved.
According to the embodiment of the application, based on the catalytic bed layer with the thickness of 5-40 mm, the thicknesses of the upper quartz cotton layer 41 and the lower quartz cotton layer 42 can be respectively and independently 0.5-3 mm, for example, the thicknesses can be respectively and independently 1mm, 2mm or 2.5mm, and the like, so that enough fixing strength can be provided for the catalytic bed layer, the structural stability of the fixed catalytic bed layer is ensured, and the influence on the flow speed and the detection efficiency of air flow due to the over-thickness of the quartz cotton layer can be avoided.
Chromatographic column 50
According to an embodiment of the invention, the CO of the chromatographic column 50 is understood with reference to FIG. 1xThe gas outlet end 51 passes through the lower section 23 of the nozzle inner passage 20 and abuts against the lower quartz wool layer 42, and a gas passage 60 is formed between the chromatographic column 50 and the nozzle inner passage 20. Thereby carrying COxThe gas to be detected flows out of the chromatographic column and enters the catalytic bed layer through the quartz cotton layer to ensure that H is2(or H)2And tail gas blow) from the gas channel through the quartz wool layer into the catalytic bed. It will be appreciated that the column 50 is a gas chromatography column for separating CO from a sample gasxA gas. Note that, due to the different COxDifferent separation times of (2) and thus different COxCH obtained by conversion4The response times in the FID detectors differ, whereby different CO in the gas to be detected can also be obtained separatelyxThe concentration of (c).
The chromatographic column 50 may be either a capillary column or a packed column, according to embodiments of the present application. When a packed column is selected, H is supplied only in the gas passage2Then the method is finished; when the capillary column is selected, tail blowing air is required to be introduced into the air channel to serve as supplementary air, so that the column effect can be improved, and the sensitivity of the FID detector can be improved. The carrier gas used in the column may be selected from high purity Ar, high purity He, and high purity N2And high purity H2At least one of the group consisting of high purity Ar, high purity He and high purity N2And high purity H2The purity of (a) may be not less than 99.9% or 99.99%, respectively, independently.
According to the embodiment of the application, the flow rate of the carrier gas adopted by the chromatographic column can be 2-50 ml/min (for example, 10ml/min, 20ml/min, 30ml/min or 40ml/min and the like), and H flows into the gas channel2The flow rate of (a) may be 20 to 40ml/min (e.g., 25ml/min, 30ml/min, or 35 ml/min), H2The volume ratio of the carrier gas to the carrier gas may be 0.4 to 50, and may be, for example, 1,5. 10, 20, 30, or 40, etc.; further, when the chromatographic column 50 is a capillary column, H is introduced2And tail gas blowing enters the catalytic bed layer from the gas channel, the flow rate of the tail gas blowing at the moment can be 10-30 ml/min (for example, 15ml/min, 20ml/min or 25ml/min and the like), and the inventor finds that the volume ratio and the flow rate are controlled, so that the directional flow of the gas flow is facilitated, the sensitivity of the FID detector can be ensured, and the accuracy and the reliability of the detection result are ensured.
According to the examples of the present application, when chromatographic column carrier gas, H2And CH4When the air is mixed and combusted with air at the nozzle after flowing out of the self-catalytic bed layer, the flow rate of the air can be 200-400 ml/min, for example, 250ml/min, 300ml/min or 350ml/min, and the sensitivity of the FID detector can be further ensured.
In summary, the present low concentration CO of the above embodiments of the present inventionxThe FID device for methanation conversion and detection is simply transformed through a spray head of the FID detector, and a Ni-based catalyst with high activity at low temperature (such as less than 350 ℃ or 250 ℃) is adopted, so that the temperature of the detector can provide heat for the methane conversion process, extra heating, temperature control and heat preservation equipment are not needed, an extra conversion chamber and a gas pipeline are not needed, the methane conversion furnace and the FID detector can be integrated, and low-concentration CO is carried at the momentxThe carrier gas may be contacted with H at the outlet of the column2(and tail gas blowing) are mixed and then pass through the catalytic bed layer section, and CO is finished at the set temperature (such as 200-350 ℃) of FID detectionxMethanation conversion and detection of (1), wherein, COxThe methanation conversion rate of (2) is high, for example, the conversion rate can be not less than 98%. In conclusion, the FID device integrates the methane converter and the FID detector, so that the energy consumption and the space of the device are reduced, the multifunctional characteristic of the enhanced gas chromatography is directly improved, and low-concentration (such as 2-10000 ppm) CO can be better realized on the basis of not changing the size and the use condition of the FID detectorxThe method has the advantages of high detection precision, high accuracy and good reliability, and has wide application prospect.
According to yet another aspect of the present invention, the present invention provides a method of manufacturing a semiconductor deviceFID device for realizing low-concentration CO methanation conversion and detection by adopting low-concentration COxxA methanation conversion and detection method. According to an embodiment of the invention, the method comprises:
s100, carrying COxThe gas to be detected flows out of the chromatographic column and enters the catalytic bed layer to enable H to flow out2From the gas channel into the catalytic bed. According to an embodiment of the invention, the component CO to be detected is first separated from the sample gas by means of a gas chromatography columnxWill then be loaded with COxThe gas to be detected flows out of the chromatographic column and enters the catalytic bed layer. Wherein the carrier gas adopted by the chromatographic column is selected from high-purity Ar, high-purity He and high-purity N2And high purity H2At least one of; the flow rate of the carrier gas can be 2-50 ml/min, and H flows into the gas channel2The flow rate of (2) can be 20-40 ml/min, H2The volume ratio of the carrier gas to the carrier gas can be 0.4-50; further, when the column is a capillary column, H is allowed to stand2And tail gas blowing enters the catalytic bed layer from the gas channel, and the flow of the tail gas blowing can be 10-30 ml/min. It should be noted that the selection of the chromatographic column, the thickness of the catalytic bed, the selection of the catalyst, the above-mentioned related technical features, etc. have been described in detail in the foregoing section, and are not described herein again.
S200, enabling CO in the gas to be detectedxAnd H2Reacting to generate CH at the working temperature of the catalytic bed layer and the FID detector4And H2And (O). According to the embodiment of the invention, the working temperature of the FID detector is 200-350 ℃, and CO is catalyzedxWhen the methane conversion is carried out, heat can be provided for the methane conversion process only by the temperature of the detector.
S300, carrying gas H by the chromatographic column2And CH4Combining the catalytic bed layer and the catalyst layer into one path in the upper section of the nozzle inner channel, and allowing the path to flow out through the nozzle opening.
S400, enabling air to flow out of H above and in the nozzle opening2Meet to form hydrogen flame ionization region, hydrocarbon (such as CH)4) Positive ions are formed by ionization in a flame region, and weak current is formed by collection and movement under the action of a negative electrostatic field and is amplified by an electrometerForming a detection signal based on which detected CH is obtained4So as to calculate and obtain CO in the gas to be detectedxThe content value of (a). According to the embodiment of the invention, the flow rate of the air can be 200-400 ml/min, so that the sensitivity of the FID detector can be further ensured.
In summary, the embodiments of the present invention achieve low concentration of COxThe methanation conversion and detection method can directly utilize the temperature of the detector to provide heat for the methanation conversion process, does not need additional heating, temperature control and heat preservation equipment, does not need additional conversion chambers and gas pipelines, and has the advantages of simple process, low energy consumption, COxThe methanation conversion rate is high (for example, the conversion rate can be not less than 98%), and the method has the advantages of high detection precision, high accuracy and good reliability, and can better realize low-concentration (for example, 2-10000 ppm) COxThe detection has wide application prospect. It should be noted that the low concentration of CO is achieved as described abovexThe features and effects described for the FID device for methanation conversion and detection apply equally to the implementation of low concentrations of COxThe methanation conversion and detection method is not described in detail herein.
The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention. The examples do not specify particular techniques or conditions, and are performed according to techniques or conditions described in literature in the art or according to the product specification. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
Example 1
In the embodiment, the FID device provided by the invention is adopted to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxAt concentrations often below 0.1 v%, the product of the catalytic conversion is CH4In this embodiment, to calibrate CH4Provided that it contains only 100ppm of CH4The equilibrium gas of (1) is Ar.
The device is shown in FIG. 1, and the chromatographic column adopts DB-WAX capillary column with length30m, an outer diameter of 0.53mm, a column thickness of 0.25. mu.m, and a quantitative loop volume of 250. mu.l. The chromatographic column can separate CO and CO2And CH4。
Gas, H, to be detected2As can be understood from FIG. 2 in conjunction with the tail-gas flow path, the column 50 is fed with the gas to be detected and the carrier gas, and the gas channel 60 is fed with H2Blowing with tail gas, using high-purity Ar as carrier gas, capillary column flow rate is 5ml/min, introducing H in gas channel2The flow rate was 20ml/min and the tail gas flow rate was 25 ml/min. Air flows in from the nozzle, and the flow rate is 300 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.5mm, and the length is 10 mm; the inner diameter of the middle section is 2mm, and the length of the middle section is 15 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm.
In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 60 percent, and the carrier is CeO2With Al2O3The 1:1 mixture of (1) and (2) has a particle size of 40-60 meshes and is filled in the inner channel of the nozzle. The FID detector was set at a temperature of 250 ℃ and could be held constant for long periods of time. The catalytic bed layer is 10mm thick and filled in the middle of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with quartz cotton layers, and the thickness of the quartz cotton layers at the two ends is 1.5 mm.
The gas to be detected flows out of the capillary column, passes through the catalytic bed layer and then is treated by the FID detector to obtain CH4A response signal. The test result shows that the CH is passed through in the FID spectrogram4The retention time of (A) was 1.053min, the peak area was 642915, and the peak area had a linear response relationship with the concentration.
Example 2
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxAt concentrations often below 0.1 v%, the product of the catalytic conversion is CH4In this embodiment, to calibrate CH4Provided that only contains 1000ppm CH4The balance gas of the gas to be detected is Ar.
The device is shown in FIG. 1, and the chromatographic column adopts HayeSep Q packed column with length of 1.83m and outer diameter1/8 inches, column thickness 2mm, and dosing ring volume 1 ml. The chromatographic column can separate CO and CO2And CH4。
Gas, H, to be detected2As can be understood from FIG. 2 in conjunction with the tail-gas flow path, the column 50 is fed with the gas to be detected and the carrier gas, and the gas channel 60 is fed with H2By using high purity H2As carrier gas, the flow rate of the packed column is 25ml/min, and H is introduced into the gas channel2The flow rate was 20 ml/min. Air was introduced through the nozzle at a flow rate of 300 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.5mm, and the length is 10 mm; the inner diameter of the middle section is 2mm, and the length of the middle section is 15 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 60 percent, and the carrier is CeO2With Al2O3The 1:1 mixture of (1) and (2) has a particle size of 40-60 meshes and is filled in the inner channel of the nozzle. The FID detector was set at a temperature of 250 ℃ and could be held constant for long periods of time. The catalytic bed layer is 10mm thick and filled in the middle section of the inner channel of the nozzle, quartz cotton layers are respectively filled at the upper end and the lower end of the catalytic bed layer, and the thickness of the quartz cotton layers at the two ends is 1.5 mm.
The gas to be detected flows out of the packed column, passes through the catalytic bed layer and then is subjected to FID (flame ionization Detector) to obtain CH4A response signal. The test result shows that the CH is passed through in the FID spectrogram4The retention time of (A) is 1.051min, the peak area is 6430126, and the peak area has a linear response relation with the concentration.
Example 3
This example uses the apparatus provided by the present invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is usually lower than 0.1 v%, in this example, in order to verify the actual capability of the catalytic bed for conversion of trace CO, the CO volume concentration in the gas to be detected is 500ppm, and 500ppm CH is added4As an internal standard, the equilibrium gas was Ar.
As shown in FIG. 1, a DB-WAX capillary column having a length of 30m, an outer diameter of 0.53mm, a column thickness of 0.25 μm and a quantitative loop volume of 250 μ l was used as a chromatographic column. The column can be divided intoSeparate CO from CH4。
Gas, H, to be detected2As can be understood from FIG. 2 in conjunction with the tail-gas flow path, the column 50 is fed with the gas to be detected and the carrier gas, and the gas channel 60 is fed with H2Blowing with mixed tail gas, using high-purity Ar as carrier gas, capillary column flow rate is 5ml/min, introducing H in gas channel2The flow rate was 20ml/min and the tail gas flow rate was 25 ml/min. Air flows in from the nozzle, and the flow rate is 300 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.3mm, and the length is 10 mm; the inner diameter of the middle section is 1.5mm, and the length of the middle section is 20 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm. The CO flow entering the catalytic bed layer is 0.0025ml/min, and H2The ratio of the flow rate to the CO flow rate was 8000: 1. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 60 percent, and the carrier is La2O3With Al2O3The 1:1 mixture of (1) and (2) has a particle size of 100 to 120 meshes and is filled in the inner channel of the nozzle. The FID detector set temperature is 300 ℃ and can remain unchanged for a long time. It is calculated from the catalyst activity data that 14mg of catalyst needs to be filled in the CO provided by the treatment, and the thickness of the catalytic bed layer is 17mm and is filled in the middle section of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with a quartz cotton layer, and the thickness of the quartz cotton layers at the two ends is 1.2 mm.
The gas to be detected can be discharged from the capillary column and can be used for completely converting CO into CH after passing through the catalytic bed layer4Obtaining CH via FID detector4And responding to the signal, thereby obtaining corresponding CO concentration information. The test result shows that CH obtained by CO conversion in FID spectrogram4The retention time of (A) was 0.823min, the peak area was 3166356, and the original (used as calibration) CH was passed4Has a retention time of 1.051min and a peak area of 3214686, and can realize 98.5 percent conversion of CO and 100 percent CH by calculation4And selectivity, the device can be used for integrally detecting trace CO.
Example 4
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the gas to be detected containsCO ofxThe concentration is usually lower than 0.1 v%, in this example, in order to verify the actual capability of the catalytic bed for conversion of trace CO, the CO volume concentration in the gas to be detected is 500ppm, and 500ppm CH is added4As an internal standard, the equilibrium gas was Ar.
The apparatus used is shown in FIG. 1, and the column used was a HayeSep Q packed column of length 1.83m, outer diameter 1/8 inches, column thickness 2mm, and quantitative loop volume 1 ml. The chromatographic column can separate CO from CH4。
Gas, H, to be detected2The gas flow path is understood in conjunction with fig. 2, with the gas to be detected and the carrier gas being introduced into the chromatographic column 50 and the gas channel 60 being supplied with H2By using high purity H2As carrier gas, the column flow is 20ml/min, and H is introduced into the gas channel2The flow rate was 40 ml/min. Air flows in from the nozzle, and the flow rate is 300 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.3mm, and the length is 10 mm; the inner diameter of the middle section is 1.5mm, and the length of the middle section is 20 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm.
The flow rate of CO entering the catalytic bed layer is 0.01ml/min, and H2Flow rate and COxThe ratio of flow rates was 5999: 1. In this example, a Ni-based catalyst was used, the active component Ni was 80% by mass, and the carrier was Al2O3、CeO2The 2:1 mixture of (1) has a particle size of 60-80 meshes, and is filled in the inner channel of the nozzle. The FID detector was set at 230 ℃ and could remain unchanged for a long time. Calculating from the catalyst activity data, treating the supplied CO2When 50mg of catalyst needs to be filled, the thickness of a catalytic bed layer is 10mm, the catalytic bed layer is filled in the middle section of the inner channel of the nozzle, quartz cotton layers are respectively filled at the upper end and the lower end of the catalytic bed layer, and the thickness of the quartz cotton layers at the two ends is 1.5 mm.
The detection gas can completely convert CO into CH after flowing out of the packed column and passing through the catalytic bed layer4Obtaining CH via FID detector4And responding to the signal, thereby obtaining corresponding CO concentration information. The test result shows that CH obtained by CO conversion in FID spectrogram4The retention time of (a) was 0.821min, the peak area was 3170287, the original CH4Has a retention time of 1.045min and a peak area of 3215301, and can realize 98.6 percent conversion of CO and 100 percent CH by calculation4And selectivity, the device can be used for integrally detecting trace CO.
Example 5
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is often less than 0.1 v%, in this example to verify that the catalytic bed is actually for trace amounts of CO2Ability to convert, providing CO in the gas to be detected2The volume concentration is 100ppm, and 100ppm CH is added4As an internal standard, the equilibrium gas was Ar.
As shown in FIG. 1, the chromatographic column 4 used was a DB-WAX capillary column having a length of 30m, an outer diameter of 0.53mm, a column thickness of 0.25 μm and a quantitative loop volume of 25. mu.l. The chromatographic column can separate CO2And CH4。
Gas, H, to be detected2As can be understood from FIG. 2 in conjunction with the tail-gas flow path, the column 50 is fed with the gas to be detected and the carrier gas, and the gas channel 60 is fed with H2Blowing with mixed tail gas, using high-purity Ar as carrier gas, capillary column flow rate of 5ml/min, introducing H in gas channel2The flow rate was 25ml/min and the tail gas flow rate was 30 ml/min. Air was introduced through the nozzle at a flow rate of 250 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.7mm, and the length is 10 mm; the inner diameter of the middle section is 1mm, and the length of the middle section is 15 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm.
CO entering the catalytic bed2The flow rate is 0.0005ml/min, H2Flow rate and CO2The flow rate ratio was 50000: 1. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 40%, and the carrier is Eu2O3With Al2O3The 1:4 mixture of (1) and (4) is filled in the inner channel of the nozzle, and the particle size of the mixture is 40-50 meshes. The FID detector was set to a temperature of 340 c and could remain unchanged for a long period of time. Processing the supplied CO by deducting from the catalyst activity data210mg of the catalyst is required to be filled,the catalytic bed layer with thickness of 10mm is filled in the middle of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with a quartz cotton layer, and the thickness of the quartz cotton layers at the two ends is 1.5 mm.
The gas to be detected can flow out of the capillary column and pass through the catalytic bed layer to remove CO2Complete conversion to CH4Obtaining CH via FID detector4In response to the signal, thereby obtaining the corresponding CO2The concentration information of (1). The test result shows that CO in the FID spectrogram2Conversion of the resulting CH4The retention time of (1) is 3.019min, the peak area is 635336, original CH4The retention time of the catalyst bed is 1.051min, the peak area is 643053, and the catalyst bed can realize CO by calculation298.8% conversion and 100% CH4Selectivity, the device can realize micro CO integrally2Detection of (3).
Example 6
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is usually lower than 0.1 v%, in this embodiment, in order to verify the actual trace CO in the catalytic bed2Ability to convert, providing CO in the gas to be detected2The volume concentration is 200ppm, and 200ppm CH is added4As an internal standard, the equilibrium gas was Ar.
The apparatus used is shown in FIG. 1, and the column used was a HayeSep Q packed column of length 1.83m, external diameter 1/8 inches, column thickness 2mm, and quantitative loop volume 1 ml. The chromatographic column can separate CO2And CH4。
Gas, H, to be detected2The gas flow path is understood in conjunction with fig. 2, with the gas to be detected and the carrier gas being introduced into the chromatographic column 50 and the gas channel 60 being supplied with H2By using high purity H2As carrier gas, the column flow is 20ml/min, and H is introduced into the gas channel2The flow rate was 40 ml/min. Air was introduced through the nozzle at a flow rate of 400 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.7mm, and the length is 10 mm; the inner diameter of the middle section is 1mm, and the length of the middle section is 22 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm.
CO entering the catalytic bed2The flow rate is 0.004ml/min, H2Flow rate and CO2The ratio of flow rates was 14999: 1. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 40 percent, and the carrier is Al2O3、CeO2With Eu2O3The 3:2:1 mixture has a particle size of 60-80 meshes and is filled in the inner channel of the nozzle. The FID detector was set at a temperature of 250 ℃ and could be held constant for long periods of time. Processing the supplied CO by deducting from the catalyst activity data2When 95mg of catalyst is required to be filled, the thickness of the catalytic bed layer is 19mm, and the catalytic bed layer is filled in the middle section of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with a quartz cotton layer, and the thickness of the quartz cotton layers at the two ends is 1.2 mm.
The CO can be separated after the detection gas flows out of the packed column and passes through the catalytic bed layer2Complete conversion to CH4Obtaining CH via FID detector4In response to the signal, thereby obtaining the corresponding CO2The concentration information of (1). The test result shows that CO in the FID spectrogram2Conversion of the resulting CH4The retention time of (A) was 3.015min, the peak area was 1262844, the original CH4The retention time of (2) is 1.044min, the peak area is 1286033, and the calculation results show that the catalytic bed can realize CO298.2% conversion and 100% CH4Selectivity, the device can realize micro CO integrally2Detection of (3).
Example 7
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is often less than 0.1 v%, in this example to verify that the catalytic bed is actually for trace amounts of COxAbility to convert, providing CO in the gas to be detectedxThe volume concentration is 200ppm, wherein CO and CO2In a volume concentration of 100ppm and 100ppm, respectively, and adding 100ppm CH4As an internal standard, the equilibrium gas was Ar.
The device is shown in FIG. 1, and the chromatographic column adopts DB-WAX capillary column with length of 30m, outer diameter of 0.53mm, and column thickness of 0.25 μmThe volume of the measuring ring was 250. mu.l. The chromatographic column can separate CO and CO2And CH4。
Gas, H, to be detected2As can be understood from FIG. 2 in conjunction with the tail-gas flow path, the column 50 is fed with the gas to be detected and the carrier gas, and the gas channel 60 is fed with H2Blowing with H2H content of 50 v%2Ar is used as carrier gas, the flow rate of the capillary column is 5ml/min, and H is introduced into the gas channel2The flow rate was 20ml/min and the tail gas flow rate was 25 ml/min. Air was introduced through the nozzle at a flow rate of 400 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.8mm, and the length is 10 mm; the inner diameter of the middle section is 1.2mm, and the length of the middle section is 15 mm; the inner diameter of the lower section is 2mm, and the length is 40 mm.
CO entering the catalytic bedxThe flow rate is 0.001ml/min, H2Flow rate and COxThe ratio of flow rates was 22499.25: 1. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 60 percent, and the carrier is Al2O3The particle size of the powder is 60-80 meshes, and the powder is filled in a channel in a nozzle. The FID detector was set at 240 ℃ and could remain unchanged for a long period of time. Processing the supplied CO by deducting from the catalyst activity dataxWhen 10mg of catalyst is required to be filled, the thickness of the catalytic bed layer is 10mm, and the catalytic bed layer is filled in the middle section of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with a quartz cotton layer, and the thickness of the quartz cotton layers at the two ends is 1.5 mm.
The gas to be detected can flow out of the capillary column and pass through the catalytic bed layer to remove COxComplete conversion to CH4Obtaining CH via FID detector4In response to the signal, thereby obtaining the corresponding COxThe concentration information of (2). The test result shows that the peak area of 0.822min obtained by CO conversion in the FID spectrogram is 636615, and CO is2Conversion of the resulting CH4The retention time of (a) was 3.014min, the peak area was 630827, the original CH4Has a retention time of 1.051min and a peak area of 643045, and can realize 99 percent conversion of CO and 100 percent CH by calculation4Selectivity, CO298.1% conversion and 100% CH4The selectivity of the reaction is improved by the following steps,the device can realize integration of trace COxDetection of (3).
Example 8
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is often less than 0.1 v%, in this example to verify that the catalytic bed is actually for trace amounts of COxAbility to convert, providing CO in the gas to be detectedxThe volume concentration is 200ppm, wherein CO and CO2In a volume concentration of 100ppm and 100ppm, respectively, and adding 100ppm CH4As an internal standard, the balance gas was Ar.
The apparatus used is shown in FIG. 1, and the column used was a HayeSep Q packed column of length 1.83m, outer diameter 1/8 inches, column thickness 2mm, and quantitative loop volume 1 ml. The chromatographic column can separate CO and CO2And CH4。
Gas, H, to be detected2The gas flow path is understood in conjunction with fig. 2, with the gas to be detected and the carrier gas being introduced into the chromatographic column 50 and the gas channel 60 being supplied with H2High-purity Ar is used as carrier gas, the column flow is 20ml/min, and H is introduced into a gas channel2The flow rate was 35 ml/min. Air was introduced through the nozzle at a flow rate of 350 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.8mm, and the length is 10 mm; the inner diameter of the middle section is 1.2mm, and the length of the middle section is 15 mm; the inner diameter of the lower section is 2mm, and the length is 40 mm.
CO entering the catalytic bedxThe flow rate is 0.004ml/min, H2Flow rate and COxThe ratio of flow rates was 8750: 1. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 40%, and the carrier is Eu2O3、CeO2With Al2O3The 1:1:5 mixture of (1) and (5) has a particle size of 100-120 meshes and is filled in the channel in the nozzle. The FID detector was set at 220 ℃ and could remain unchanged for a long time. Processing the supplied CO by deducting from the catalyst activity datax40mg of catalyst is required to be filled, and the thickness of the catalytic bed layer is 7.1mm, and the catalytic bed layer is filled in the middle section of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filledThe thickness of the quartz cotton layer at both ends is 1.2 mm.
The CO can be separated after the detection gas flows out of the packed column and passes through the catalytic bed layerxComplete conversion to CH4Obtaining CH via FID detector4In response to the signal, thereby obtaining the corresponding COxThe concentration information of (1). The test result shows that the peak area of 0.820min obtained by CO conversion in the FID spectrogram is 635925, and CO is2Conversion of the resulting CH4The retention time of (A) was 3.017min, the peak area was 633353, the original CH4Has a retention time of 1.049min and a peak area of 642998, and can realize 98.9 percent conversion of CO and 100 percent CH by calculation4Selectivity, CO298.5% conversion and 100% CH4Selectivity, the device can realize micro CO integrallyxDetection of (3).
Example 9
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is often less than 0.1 v%, in this example to verify that the catalytic bed is actually for trace amounts of COxAbility to convert, providing CO in the gas to be detectedxThe volume concentration is 2000ppm, wherein CO and CO2In the presence of 1000ppm CH, and 1000ppm CH4As an internal standard, the balance gas was Ar.
As shown in FIG. 1, the apparatus used was a DB-WAX capillary column as the column 4, which had a length of 30m, an outer diameter of 0.53mm, a column thickness of 0.25 μm and a quantitative loop volume of 250. mu.l. The chromatographic column can separate CO and CO2And CH4。
Gas, H, to be detected2As can be understood from FIG. 2 in conjunction with the tail-gas flow path, the column 50 is fed with the gas to be detected and the carrier gas, and the gas channel 60 is fed with H2Blowing with mixed tail gas, using high-purity Ar as carrier gas, capillary column flow rate is 5ml/min, introducing H in gas channel2The flow rate was 30ml/min and the tail-blow flow rate was 10 ml/min. Air was introduced through the nozzle at a flow rate of 400 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.5mm, and the length is 10 mm; the inner diameter of the middle section is 1.2mm, and the length of the middle section is 15 mm; the inner diameter of the lower section is 2mm, and the length is 30 mm.
CO entering the catalytic bedxThe flow rate is 0.01ml/min, H2Flow rate and COxThe flow rate ratio was 3000: 1. In this example, a Ni-based catalyst was used, the active component Ni was 55% by mass, and CeO was used as a carrier2And ZrO2The 1:10 mixture of (1) and (2) is filled in the inner channel of the nozzle, and the particle size of the mixture is 40-50 meshes. The FID detector was set at a temperature of 250 ℃ and could be held constant for long periods of time. Processing the supplied CO by deducting from the catalyst activity data2When 10mg of catalyst is required to be filled, the thickness of the catalytic bed layer is 10mm, and the catalytic bed layer is filled in the middle section of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with a quartz cotton layer, and the thickness of the quartz cotton layers at the two ends is 1.5 mm.
The gas to be detected can flow out of the capillary column and pass through the catalytic bed layer to remove COxComplete conversion to CH4Obtaining CH via FID detector4In response to the signal, thereby obtaining the corresponding COxThe concentration information of (1). The test result shows that the peak area of 0.825min obtained by CO conversion in the FID spectrogram is 6399996, and CO is2Conversion of the resulting CH4The retention time of (A) was 3.017min, the peak area was 6412861, the original CH4Has a retention time of 1.050min and a peak area of 6432157, and can realize 99.5 percent conversion of CO and 100 percent CH by calculation4Selectivity, CO299.7% conversion and 100% CH4Selectivity, the device can realize micro CO integrallyxDetection of (3).
Example 10
The embodiment adopts the device provided by the invention to realize trace COxThe detection and analysis of (3). In practice, the CO contained in the gas to be detectedxThe concentration is often less than 0.1 v%, in this example to verify that the catalytic bed is actually for trace amounts of COxAbility to convert, providing CO in the gas to be detectedxThe volume concentration is 2000ppm, wherein CO and CO2In the presence of 1000ppm CH, and 1000ppm CH4As an internal standard, the equilibrium gas was Ar.
The apparatus used is shown in FIG. 1, and the column used was a HayeSep Q packed column of length 1.83m, outer diameter 1/8 inches, column thickness 2mm, and quantitative loop volume 1 ml. The chromatographic column can separate CO and CO2And CH4。
Gas, H, to be detected2The gas flow path is understood in conjunction with fig. 2, with the gas to be detected and the carrier gas being introduced into the chromatographic column 50 and the gas channel 60 being supplied with H2As shown in FIG. 2, high purity Ar is used as carrier gas, the column flow is 20ml/min, and H is introduced into a gas channel2The flow rate was 30 ml/min. Air was introduced through the nozzle at a flow rate of 400 ml/min.
In the inner channel of the nozzle, the inner diameter of the upper section is 0.5mm, and the length is 10 mm; the inner diameter of the middle section is 1.2mm, and the length of the middle section is 20 mm; the inner diameter of the lower section is 2mm, and the length is 40 mm.
CO entering the catalytic bedxThe flow rate is 0.04ml/min, H2Flow rate and COxThe flow ratio was 750: 1. In the example, a Ni-based catalyst is adopted, the mass fraction of the active component Ni is 45 percent, and the carrier is SiO2And Sm2O3The 1:1 mixture of (1) and (2) has a particle size of 50-60 meshes and is filled in the inner channel of the nozzle. The FID detector was set at a temperature of 250 ℃ and could be held constant for long periods of time. Processing the supplied CO by deducting from the catalyst activity dataxWhen 80mg of catalyst is required to be filled, the thickness of the catalytic bed layer is 15mm, and the catalytic bed layer is filled in the middle section of the channel in the nozzle. The upper end and the lower end of the catalytic bed layer are respectively filled with a quartz cotton layer, and the thickness of the quartz cotton layers at the two ends is 1.2 mm.
The CO can be separated after the detection gas flows out of the packed column and passes through the catalytic bed layerxComplete conversion to CH4Obtaining CH via FID detector4In response to the signal, thereby obtaining the corresponding COxThe concentration information of (1). The test result shows that the FID spectrogram has a CO conversion time of 0.826min, a peak area of 6354815, and CO2Conversion of the resulting CH4The retention time of (3.016 min), the peak area of 6374111, original CH4The retention time of (A) was 1.046min, the peak area was 6431999, and the catalyst bed was calculated to beThe layer can achieve 98.8% conversion of CO and 100% CH4Selectivity, CO299.1% conversion and 100% CH4Selectivity, the device can realize micro CO integrallyxDetection of (3).
Results and conclusions: as can be seen from examples 1 to 10, the present invention employs the FID apparatus shown in FIG. 1 to treat the low concentration (100ppm to 2000ppm) COxDue to different CO when the gas to be detected is detectedx(e.g., CO and CO)2) The separation times required for separation by the gas chromatography column are different and therefore different COxCH obtained by conversion4The response time at the time of detection by the FID detector is different, and CH reaching the nozzle opening through different stages4With different CO obtainedxCH obtained by conversion4Can further respectively obtain different CO in the gas to be detectedxThe concentration of (c). In addition, to verify CO in the present inventionxHigh conversion and CH4In the present embodiment, the same volume of CH is used4Internal standard is made, and different CO in FID spectrogram is comparedxCH obtained by conversion4Peak area of (a) and CH used as an internal standard4Peak area of (2), verification of COxConversion rate of (2) and catalytic conversion of CH4And (4) selectivity. It can be seen from the results of the tests of the embodiments 1 to 10 of the present invention (wherein the embodiments 1 to 2 are mainly used as a control), that the low concentration CO can be realized by the embodiments of the present inventionxThe FID device and method for methanation conversion and detection can realize low-concentration CO on the premise of not adopting external heating, temperature control and heat preservation equipmentxThe method has the advantages of high accuracy and good reliability.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (10)

1. Realizing low-concentration COxFID device of methanation conversion and detection, characterized by includes:
a nozzle housing;
the inner nozzle channel penetrates through the nozzle shell along the height direction of the nozzle shell and comprises an upper section, a middle section and a lower section which are sequentially communicated from top to bottom, the inner diameter of the upper section is smaller than that of the middle section, the inner diameter of the middle section is smaller than that of the lower section, the inner diameter of the joint of the upper section and the middle section is gradually increased from top to bottom, and the inner diameter of the joint of the middle section and the lower section is gradually increased from top to bottom;
the catalytic bed layer is arranged in the middle section of the nozzle inner channel and comprises a Ni-based catalyst, and the Ni-based catalyst comprises metal Ni and metal oxide;
the quartz cotton layer is arranged in the middle section of the inner channel of the nozzle and comprises an upper quartz cotton layer and a lower quartz cotton layer which are used for fixing the catalytic bed layer;
chromatography column, CO of said chromatography columnxThe gas outlet end penetrates through the lower section of the nozzle inner channel and is abutted against the lower quartz cotton layer, and a gas channel is formed between the chromatographic column and the nozzle inner channel.
2. The FID device of claim 1, wherein the upper portion of the nozzle housing is conical, pyramidal, intrados conical, or extrados conical.
3. The FID device of claim 1, wherein the Ni-based catalyst has a metal oxide content of 10 to 60 wt%;
optionally, the Ni-based catalyst comprises metallic Ni and a metal oxide support comprising a metal selected from Al2O3、SiO2、CeO2、La2O3、Eu2O3、ZrO2、Sm2O3At least one of the above, wherein the mass ratio of the metal Ni to the metal oxide carrier is (40-90): (10-60);
optionally, the particle size of the catalyst adopted by the catalytic bed layer is 40-200 meshes;
optionally, the thickness of the catalytic bed layer is 5-40 mm, and the thicknesses of the upper quartz cotton layer and the lower quartz cotton layer are respectively and independently 0.5-3 mm.
4. A FID device according to any of claims 1 to 3 wherein the chromatography column is a capillary or packed column;
optionally, in the inner channel of the nozzle, the inner diameter of the upper section is 0.1-3 mm, and the length is 1-20 mm; the inner diameter of the middle section is 1-6 mm, and the length of the middle section is 6-30 mm; the inner diameter of the lower section is 2-10 mm, and the length is 10-80 mm.
5. A FID device according to any of claims 1 to 3 wherein the lower middle portion of the nozzle housing is removably attached to a base provided below the nozzle housing;
optionally, the nozzle housing is threadably connected to the base.
6. The FID device of claim 5, wherein the nozzle housing further comprises an insulating transition layer disposed above the location where the nozzle housing is connected to the base and dividing the nozzle housing into two portions that are not in communication up and down.
7. A FID device of any of claims 1-6 for low concentration COxThe methanation conversion and detection method is characterized by comprising the following steps:
(1) make CO carriedxThe gas to be detected flows out of the chromatographic column and enters the catalytic bed layer to enable H to flow out2Entering the catalytic bed layer from a gas channel;
(2) by CO in the gas to be detectedxAnd H2Reacting to generate CH at the working temperature of the catalytic bed layer and the FID detector4And H2O；
(3) Gas, H, is carried by chromatographic column2And CH4Combining the catalytic bed layer and the catalyst layer into one path at the upper section of the inner channel of the nozzle, and allowing the path to flow out through the nozzle opening;
(4) h for letting air out over and in the nozzle openings2Meeting to form a hydrogen flame ionization region, ionizing hydrocarbon in the flame region to form positive ions, collecting and moving the positive ions under the action of a negative electrostatic field to form weak current, amplifying the weak current by an electrometer to form a detection signal, and obtaining the detected CH based on the detection signal4So as to calculate and obtain CO in the gas to be detectedxThe content value of (a).
8. The method according to claim 7, characterized in that, before step (1), the component to be detected CO is separated from the sample gas by means of a chromatographic columnxObtaining the gas to be detected;
optionally, in step (1), the carrier gas used in the chromatographic column is selected from high-purity Ar, high-purity He and high-purity N2And high purity H2At least one of (a).
9. The method according to claim 7 or 8, wherein in step (1), the carrier gas has a flow rate of2-50 ml/min, H flowing into the gas channel2The flow rate of (A) is 20-40 ml/min, H2The volume ratio of the carrier gas to the carrier gas is 0.4-50;
optionally, in step (1), H is reacted2And tail gas blowing enters the catalytic bed layer from a gas channel, wherein the flow of the tail gas blowing is 10-30 ml/min;
optionally, in the step (3), the flow rate of the air is 200-400 ml/min.
10. The method according to claim 7, wherein in the step (2), the operating temperature of the FID detector is 200-350 ℃.
CN202210255876.5A 2022-03-15 2022-03-15 Achieving low concentration of COxFID device and method for methanation conversion and detection Pending CN114609280A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210255876.5A CN114609280A (en) 2022-03-15 2022-03-15 Achieving low concentration of COxFID device and method for methanation conversion and detection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210255876.5A CN114609280A (en) 2022-03-15 2022-03-15 Achieving low concentration of COxFID device and method for methanation conversion and detection

Publications (1)

Publication Number Publication Date
CN114609280A true CN114609280A (en) 2022-06-10

Family

ID=81863698

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210255876.5A Pending CN114609280A (en) 2022-03-15 2022-03-15 Achieving low concentration of COxFID device and method for methanation conversion and detection

Country Status (1)

Country Link
CN (1) CN114609280A (en)

Similar Documents

Publication Publication Date Title
JP5402114B2 (en) Gas chromatograph detector
JP3482497B2 (en) Isotope composition analyzer
US8578755B2 (en) Device for providing gases, in particular for isotopic ratio analysis
JPH03146862A (en) Analysis method and apparatus for isotope composition
CN108333284B (en) Method and system for detecting carbon-containing compound based on catalytic conversion technology
US20230322551A1 (en) Steam reforming
CN109142503A (en) A kind of mass spectrometry detection device in situ for heterogeneous catalytic reaction intermediate and product
Sadykov et al. Partial oxidation of methane on Pt-supported lanthanide doped ceria–zirconia oxides: Effect of the surface/lattice oxygen mobility on catalytic performance
JP2005522008A (en) Eddy current atmospheric pressure chemical ionization source for mass spectrometry
CN218646911U (en) FID device for realizing low-concentration COx methanation conversion and detection
CN114609280A (en) Achieving low concentration of COxFID device and method for methanation conversion and detection
JP4634720B2 (en) Gas detection method and detection apparatus
CA2299248A1 (en) On-line analysis of process gas during the production of ketene
US20140127823A1 (en) Device and Method for Producing CO2, N2 and/or SO2 from a Sample
JPH05215719A (en) Analysis apparatus and method for detect- ing oxygen compound contained in complex organic mixture selectively
US10041913B2 (en) One reactor post column reaction GC/FID system using Ru catalyst
JP2005265810A (en) Quantitative analysis method for formaldehyde or the like
CN112763587B (en) Gas chromatography-microreactor coupling device and analysis method
JP3351659B2 (en) Reducer for nitrogen oxides
CA2977739C (en) Sequential oxidation-reduction reactor for post column reaction gc/fid system
KR20060055141A (en) The synthesis gas preparing apparatus and method for controlling the composition of synthesis gas
JP2005058822A (en) Selective permeation membrane type reactor
JP7356830B2 (en) Intermediate processing equipment for gas chromatographs and gas chromatographs
JPS6246259A (en) Method for analyzing carbonyl sulfide
JP4002007B2 (en) Gas phase reaction analyzer

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination