Butene measurement pretreatment device and composition measurement method

Abstract

The butylene determination pretreatment device provided by the invention comprises: a sample introduction system, wherein the sample introduction system comprises a steel cylinder for containing a sample and a pretreatment sample introduction device communicated with the steel cylinder; the pretreatment sampling device is located at the front end of the waste gas treatment system, and the waste gas treatment system is connected with the pretreatment sampling device through a switching valve and a pipeline; the detection system comprises a gas chromatograph and a gas source which are connected, and the pretreatment sampling device is connected with the detection system; the pretreatment sampling device comprises a purification module, a heating module and a pressure reduction module which are connected, the purification module is connected with the steel cylinder, the heating module is arranged on the right side of the purification module, the pressure reduction module is arranged on the right side of the heating module, and the pressure reduction module is connected with the waste gas treatment system and the gas chromatograph; the waste gas treatment system comprises an adsorption device, a gas collection part and a flow control part; non-uniform sample gasification is avoided through the pretreatment sampling device, the obtained gas analysis result is good in repeatability, and a waste gas treatment device is added to complete sample purification.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical product monitoring equipment, in particular to a butene determination pretreatment device and a determination method. BACKGROUND

[0002] As an important chemical raw material, the demand for butene is growing, and at the same time, due to the increasing purity requirements of butene for the production of many chemicals, the industrial 1-butene purity is generally required to be above 99%, and the main impurities include isobutene, trans-2-butene, cis-2-butene, 1,3-butadiene, n-butane and isobutane, etc. Carbon four fraction, these hydrocarbon substances are similar in structure or similar in nature, and belong to difficult to separate substances.

[0003] The continuous progress of science and technology has driven the rapid development of testing technology, and the updating of testing instruments has followed, and the functions of the instruments are also continuously enhanced. At the same time, the increase of automatic detection, automatic control and other functions makes the instrument more compact and the structure more complex to adapt to various complex detection tasks. The determination principle of butene pretreatment device involves high pressure technology and precision control technology, and its basic principle is to use high pressure to introduce the sample to be tested into a gas-liquid converter, and to adjust the sample flow and sample amount by precisely controlling the opening and closing of the valve to ensure the accuracy of the analysis results. At the same time, the device also needs to consider the stability and fluidity of the sample, as well as the pressure resistance and corrosion resistance of the valve, etc. to ensure accurate analysis results.

[0004] At present, the gas sampling commonly used in the laboratory has a gas sampling valve and a flash evaporator, but the existing technology is not suitable for the determination of butene composition. Direct sampling with a gas valve is suitable for gas sample analysis, but not for liquid butene containing multiple components. Because when butene gas is directly sampled by a gas valve, the pressurized butene needs to be gasified at normal pressure, but the butene gasification at normal pressure is not uniform and not complete, resulting in inaccurate determination results. The method of using a steel cylinder to sample liquid and then gasifying it by a flash evaporator before entering a gas chromatograph for analysis has the problem of waste gas pollution. SUMMARY

[0005] In view of the deficiencies of the existing technology, the present application provides a butene determination pretreatment device and a determination method. The butene determination pretreatment device provided by the present application comprises:

[0006] A sampling system, the sampling system comprises a steel cylinder for containing a sample and a pretreatment sampling device in communication with the steel cylinder; a waste gas treatment system, the pretreatment sampling device is located at the front end of the waste gas treatment system, and the waste gas treatment system is connected with the pretreatment sampling device through a switching valve and a pipeline; a detection system, the detection system comprises a gas chromatograph and a gas source connected thereto, and the pretreatment sampling device is connected with the detection system;

[0007] The pretreatment sample injection device includes a purification module, a heating module, and a pressure reducing module connected together. The purification module is connected to the gas cylinder. The heating module is located to the right of the purification module. The pressure reducing module is located to the right of the heating module. The pressure reducing module is connected to the waste gas treatment system and the gas chromatograph. The waste gas treatment system includes an adsorption device, a gas collection section, and a flow control section.

[0008] In some embodiments, the purification module includes a primary filter and a secondary filter connected together; the heating module is a gas-liquid converter, a heater, and a temperature sensor connected together; the pressure reducing module includes a pipeline insulation sleeve and a pressure reducing valve, the left side of the pipeline insulation sleeve is connected to the pressure reducing valve via a pipeline, and the right side is connected to the gas chromatograph via a pipeline.

[0009] In some embodiments, the gas-liquid converter is a heat-conducting container, the heater provides a heat source for the gas-liquid converter, the temperature sensor is used to sense the temperature of the gas-liquid converter, and the primary and secondary filters are gas filters.

[0010] In some embodiments, the pretreatment sample injection device further includes a housing equipped with a pressure gauge and a temperature gauge, as well as a control knob for adjusting and controlling the temperature and pressure.

[0011] In some embodiments, the housing of the pretreatment sample injection device is also provided with a valve control knob, which can control two positions. One position controls the pretreatment sample injection device to be connected to the detection system, and the other position controls the pretreatment sample injection device to be connected to the waste gas treatment system.

[0012] In some embodiments, the adsorption device in the waste gas treatment system includes a primary hydrocarbon removal device, a secondary hydrocarbon removal device, and an exhaust device connected together; the gas collection section uses a gas collection bottle; and the flow control section includes a flow sensor, a pressure sensor, and a flow totalizer connected together.

[0013] In some embodiments, the adsorption device is connected to a gas source conduit, and the flow control section is connected to the upper part of the gas source conduit.

[0014] In some embodiments, the exhaust gas treatment system includes a housing with a control panel. The control panel includes a flow meter dial, a digital display module, a power-off power supply, and a power-on power supply, as well as a wind speed control knob for adjusting the wind speed.

[0015] In some embodiments, the gas chromatograph includes a vaporization chamber, a chromatographic column, a detector, a column oven, an amplifier, and a recorder connected together.

[0016] The present invention also provides a method for composition determination, which uses the butene pretreatment apparatus described above, and includes the following steps:

[0017] Set the appropriate pressure and temperature using the pressure gauge and thermometer on the front surface of the pretreatment sample injection device, and adjust the temperature to the appropriate temperature by adjusting the control knob; at this time, the heater starts heating, and when the temperature sensor detects that the temperature of the gas-liquid converter has reached the set temperature, the heater automatically stops heating.

[0018] After sampling with a gas cylinder, connect it to the connector on the left side of the pretreatment injection device. Open the gas cylinder, and the gas enters the heating module after passing through the primary and secondary filters. With the heater and temperature sensor working together, the sample is completely vaporized through the gas-liquid converter. Adjust the pressure to a suitable pressure by adjusting the control knob. When the gas passes through the pressure reducing valve, the pressure is reduced to atmospheric pressure.

[0019] The valve control knob is used to switch back and forth to replace the gas in the pipeline. The replacement gas is introduced into the waste gas treatment system through the conduit. After passing through the primary hydrocarbon removal device and the secondary hydrocarbon removal device, the sample adsorption is completed. The sample flows through the flow sensor, flow totalizer and pressure sensor to measure the flow rate. The value is read from the flow meter dial. The wind speed control knob is adjusted to control the exhaust wind speed. The value is displayed on the digital display.

[0020] The sample enters the gas chromatograph. The instrument parameters are set according to the chromatographic conditions. The sample passes through the chromatographic column. Due to the difference in adsorption capacity of each component in the chromatographic column packing, the components in the sample are separated. The sample passes through the vaporization chamber, detector, amplifier, and recorder to calculate the volume percentage of butene.

[0021] The present invention has the following beneficial effects:

[0022] The butene determination pretreatment device provided by this invention avoids uneven sample vaporization through the pretreatment injection device, resulting in good repeatability of the obtained gas analysis results. In addition, a waste gas treatment device is added to complete the purification of the sample.

[0023] In this invention, when measuring butene samples, the butene sample is first vaporized, and a gas-liquid converter vaporization device is installed to ensure uniform vaporization of the sample and accurate measurement results. In addition, the installation of a gas purification device ensures the harmless emission of waste gas. This invention also protects the gas chromatography by adjusting the pressure reducing device to pre-depressurize the sample pressure. By adding a waste gas treatment device, harm to our living environment and health is effectively avoided.

[0024] This invention connects the sample injection device to a gas chromatograph for sample composition analysis, which improves the efficiency of product analysis and the accuracy of sample determination results in the production process. Then, the gas chromatography method is used for analysis, which can accurately determine the butene composition content.

[0025] This invention uses an integrated pretreatment device and waste gas treatment device to determine the composition of butene. It can quickly vaporize the sample, ensuring the stability and uniformity of the sample properties while achieving the analytical conditions for gas chromatography. This makes it fast, simple and direct, greatly improving the efficiency of product analysis and the accuracy of sample determination results in the production process. This device is an important means of controlling the quality of butene products and plays an important role in ensuring the stable operation of the production process.

[0026] This invention also performs graded absorption treatment on the replaced waste gas, and collects it for unified harmless treatment, reducing environmental pollution and helping to protect the health of workers. The butene determination pretreatment device provided by this invention has the characteristics of good applicability, high accuracy, and easy operation. The analytical results obtained have good repeatability, are simple to operate, and have little harm to the environment and people. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the butene determination pretreatment device shown in an embodiment of the present invention. Figure 1 ;

[0028] Figure 2 This is a schematic diagram of the butene determination pretreatment device shown in an embodiment of the present invention. Figure 2 ;

[0029] Figure 3 This is a schematic diagram of the internal structure of the pretreatment sample introduction device shown in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the waste gas treatment system structure shown in an embodiment of the present invention;

[0031] In the attached figures, the following labels are used:

[0032] 1-Sample introduction system;

[0033] 11-Gas cylinder;

[0034] 12 - Sample pretreatment device;

[0035] 121 - Purification Module;

[0036] 1211 - Primary filter element;

[0037] 1212 - Secondary filter element;

[0038] 122 - Heating module;

[0039] 1221-Gas-Liquid Converter;

[0040] 1222 - Heater;

[0041] 1223 - Temperature sensor;

[0042] 123 - Pressure Reduction Module;

[0043] 1231 - Pipeline insulation sleeve;

[0044] 1232 - Pressure reducing valve;

[0045] 124 - Box;

[0046] 1241 - Pressure gauge;

[0047] 1242 - Thermometer;

[0048] 1243 - Control knob;

[0049] 1244 - Valve control knob;

[0050] 2- Exhaust gas treatment system;

[0051] 21-Adsorption device;

[0052] 211 - Primary hydrocarbon removal unit;

[0053] 212 - Secondary hydrocarbon removal unit;

[0054] 213 - Exhaust ventilation device;

[0055] 22-Gas collection section;

[0056] 221 - Gas collecting bottle;

[0057] 23-Flow control section;

[0058] 231 - Flow sensor;

[0059] 232 - Pressure sensor;

[0060] 233-Flow Totalizer;

[0061] 24-Gas supply conduit;

[0062] 25 - Casing;

[0063] 251 - Flowmeter dial;

[0064] 252 - Digital Display Module;

[0065] 253 - Power off;

[0066] 254 - Power On;

[0067] 255 - Wind speed control knob;

[0068] 3-Switching valve;

[0069] 4-Detection system;

[0070] 41-Gas Chromatograph;

[0071] 411 - Vaporization Chamber;

[0072] 412-chromatographic column;

[0073] 413 - Detector;

[0074] 414 - Column oven;

[0075] 415 - Amplifier;

[0076] 416 - Recorder;

[0077] 42-Gas source. Detailed Implementation

[0078] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the appended claims.

[0079] Certain terms are used in this specification and the following claims to refer to specific components or parts. Those skilled in the art will understand that users or manufacturers may use different names or terms to refer to the same component or part. This specification and the following claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout this specification and the following claims are open-ended and should be interpreted as "including but not limited to". Furthermore, the term "connection" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connections made through other means.

[0080] It should be noted that in the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and "about", or "approximately", "substantially", "left and right", etc., indicating the orientation or positional relationship or parameters, are all based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, a specific size, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0081] See Figures 1-4This embodiment provides a butene determination pretreatment device, comprising: a sample injection system 1, which includes a steel cylinder 11 for holding butene samples and a pretreatment sample injection device 12 connected to the cylinder via a pipeline; an exhaust gas treatment system 2, wherein the pretreatment sample injection device 12 is located at the front end of the exhaust gas treatment system 2, and the exhaust gas treatment system 2 is connected to the pretreatment sample injection device 12 via a switching valve 3 and a pipeline; and a detection system 4, which includes a gas chromatograph 41 and a gas source 42 connected to the detection system 4, wherein the pretreatment sample injection device 12 is connected to the detection system 4; wherein the pretreatment sample injection device 12 includes a purification module connected to the detection system 4. The system comprises a purification module 121, a heating module 122, and a pressure reducing module 123. The purification module 121 is connected to the gas cylinder 11 and is used to purify solid impurities in the sample. The heating module 122 is located to the right of the purification module 121 and is used to achieve instantaneous vaporization of the sample. The pressure reducing module 123 is the last module of the pretreatment sample injection device 12 and is located to the right of the heating module 122. The pressure reducing module 123 is connected to the waste gas treatment system 2 and the gas chromatograph 41. The waste gas treatment system 2 includes an adsorption device 21, a gas collection section 22, and a flow control section 23.

[0082] The butene determination pretreatment device provided in this embodiment uses a pretreatment sample injection device 12 to instantly vaporize the sample during measurement, avoiding sample inhomogeneity, ensuring sample separation, and improving analysis efficiency. At the same time, the exhaust gas treatment system 2 is used to treat and purify the exhaust gas, reducing harm to the personal health of the analysts. This solves the problems of uneven butene vaporization, exhaust gas emission pollution, and health hazards that exist in the prior art.

[0083] In this embodiment, the purification module 121 includes a primary filter element 1211 and a secondary filter element 1212 connected together; the heating module 122 consists of a gas-liquid converter 1221, a heater 1222, and a temperature sensor 1223 connected together; the pressure reducing module 123 includes a pipeline insulation sleeve 1231 and a pressure reducing valve 1232. The left side of the pipeline insulation sleeve 1231 is connected to the pressure reducing valve 1232 via a pipeline, and the right side is connected to the gas chromatograph 41 via a pipeline. It is used to maintain the temperature of the pipeline and prevent the gas from condensing due to sudden cooling. The pipeline insulation sleeve is made of high-temperature resistant silicone glass fiber cloth.

[0084] The pressure reduction module 123 reduces the gas pressure through the pressure reducing valve 1232 to ensure that the sample can smoothly enter the gas chromatograph. In this embodiment, the primary filter element 1211 and the secondary filter element 1212 are made of stainless steel. The primary filter element is a gas filter with a filtration accuracy of 100-300 mesh, preferably 100-150 mesh; the secondary filter element is a gas filter with a filtration accuracy of 10-100 mesh, preferably 50-100 mesh; the pressure of the pressure reducing valve of the pretreatment injection device is set to 50-200 psi, preferably 50-100 psi.

[0085] In this embodiment, the gas-liquid converter 1221 is a heat-conducting container, and the heater 1222 provides a heat source for the gas-liquid converter 1221. The heater 1222 heats the gas-liquid converter 1221, and when the sample flows through it, the sample vaporizes completely instantly. The heater 1222 controls the temperature between 50-300℃, preferably 100-200℃. The temperature sensor 1223 senses the temperature of the gas-liquid converter 1221 and transmits a signal when the set value is reached, stopping the heater. The primary filter 1211 and the secondary filter 1212 are gas filters.

[0086] In this embodiment, the pretreatment injection device 12 further includes a housing 124, on which a pressure gauge 1241 and a thermometer 1242 are provided, as well as a control knob 1243 for adjusting and controlling the temperature and pressure. The housing 124 of the pretreatment injection device 12 is also provided with a valve control knob 1244, which can control two positions. One position controls the pretreatment injection device to connect with the chromatographic column in the detection system, and the other position controls the pretreatment injection device to connect with the waste gas treatment system for waste gas discharge. By switching between the first and second positions, the gas in the pipeline is replaced. The outer casing of the chamber is a cube structure with an iron shell that is opaque. In this embodiment, the pressure gauge is located at the upper left, and the temperature gauges are placed side by side at the bottom. The corresponding two sets of knobs are located on the right side. The temperature and pressure values ​​are controlled by adjusting the control knobs. The temperature setting range of the pretreatment sample injection device is 50-200℃, preferably 100-150℃. In this embodiment, the valve control knob is rotated to the right in the direction of the arrow shown in the figure.

[0087] In this embodiment, the adsorption device 21 in the waste gas treatment system 2 includes a primary hydrocarbon removal device 211, a secondary hydrocarbon removal device 212, and an exhaust device 213 connected together; the gas collection section 22 adopts a gas collection bottle 221; the flow control section 23 includes a flow sensor 231, a pressure sensor 232, and a flow totalizer 233 connected together; the packing material of the primary hydrocarbon removal device 211 is a molecular sieve, specifically 5A molecular sieve and 13X molecular sieve; the packing material of the secondary hydrocarbon removal device 212 is activated carbon.

[0088] In this embodiment, the adsorption device 21 is connected to a gas source conduit 24, and the flow control part is connected to the upper part of the gas source conduit 24. When the gas is introduced into the bottle through the conduit, the flow control device starts to work.

[0089] The exhaust gas treatment system 2 in this embodiment includes a housing 25, on which a control panel is provided. The control panel includes a flow meter dial 251, a digital display module 252, a power-off power supply 253, and a power-on power supply 254. It also includes a wind speed control knob 255 for adjusting the wind speed, which can be rotated left or right. The flow meter dial can determine the presence of air bubbles inside the pipe based on the scale. The digital display module displays the wind speed of the exhaust device. In this embodiment, the wind speed can be 5-20 m / s, preferably 10-18 m / s. In this embodiment, two or four power switches are arranged vertically, located to the right of the knob.

[0090] In this embodiment, the gas chromatograph 41 includes a vaporization chamber 411, a chromatographic column 412, a detector 413, a column oven 414, an amplifier 415, and a recorder 416 connected to each other. The detector 413 is an FID detector, and the gas source 42 is N2, H2, or air.

[0091] The chromatographic conditions of the gas chromatograph described in this embodiment are as follows:

[0092] a) Temperature program: Initial temperature 35-60℃, hold for 1 min, program temperature increase 6-10℃ / min, temperature 100℃, hold for 0 min, program temperature increase 10-20℃ / min, final temperature 190℃, hold for 20 min.

[0093] b) Carrier gas flow rate: 5–20 mL / min;

[0094] c) Inlet temperature: 200–300℃;

[0095] d) Flow split ratio: 20:1~100:1;

[0096] e) Detector temperature: 200–300℃;

[0097] f) Column flow rate: 5 mL / min;

[0098] g) Hydrogen flow rate: 30-40 mL / min;

[0099] h) Air flow rate: 300~400mL / min;

[0100] Furthermore, the gas chromatograph is a flame ionization detector.

[0101] Furthermore, the chromatographic column 19095P-S23 has dimensions of 30m × 0.53mm × 15μm.

[0102] The preferred chromatographic conditions for the gas chromatograph are as follows:

[0103] a) Temperature program: Initial temperature 40℃, hold for 1 min, program temperature increase 7.5℃ / min, temperature 100℃, hold for 0 min, program temperature increase 15℃ / min, final temperature 190℃, hold for 20 min.

[0104] b) Carrier gas flow rate: 5 mL / min;

[0105] c) Inlet temperature: 200℃;

[0106] d) Split ratio: 20:1;

[0107] e) Detector temperature: 200℃;

[0108] f) Column flow rate: 5 mL / min;

[0109] g) Hydrogen flow rate: 35 mL / min;

[0110] h) Air flow rate: 300 mL / min.

[0111] Another embodiment of the present invention provides a method for composition determination, which uses the butene determination pretreatment device as described in the foregoing embodiments, and includes the following steps:

[0112] The appropriate pressure and temperature are set by the pressure gauge 1241 and temperature gauge 1242 on the front surface of the pretreatment sample injection device 12, and the temperature is adjusted to a suitable temperature by adjusting the control knob 1243. At this time, the heater 1222 starts to heat. When the temperature sensor 1223 detects that the temperature of the gas-liquid converter 1221 has reached the set temperature, the heater 1222 automatically stops heating.

[0113] After sampling using cylinder 11, it is connected to the left connector of the pretreatment injection device 12. When cylinder 11 is opened, the gas enters the heating module 122 after passing through primary and secondary filtration. With the heater 1222 and temperature sensor 1223 working together, the sample is completely vaporized through gas-liquid converter 1221. The pressure is adjusted to a suitable pressure by adjusting the control knob. When the gas passes through the pressure reducing valve, the pressure is reduced to atmospheric pressure.

[0114] The valve control knob 1244 is used to switch back and forth to replace the gas in the pipeline. The replacement gas is introduced into the waste gas treatment system through the conduit. After passing through the primary hydrocarbon removal device 211 and the secondary hydrocarbon removal device 212, the sample adsorption is completed. The sample flows through the flow sensor 231, the flow totalizer 233 and the pressure sensor 232, which can measure the flow rate. The value is read from the flow meter dial. The wind speed control knob is adjusted to control the exhaust wind speed. The value is displayed on the digital display.

[0115] The sample enters the gas chromatograph. The instrument parameters are set according to the chromatographic conditions. The sample passes through the chromatographic column 412. Due to the difference in adsorption capacity of each component in the chromatographic column packing, the components in the sample are separated. The sample passes through the vaporization chamber 411, detector 413, amplifier 415, and recorder 416. The volume percentage of butene is calculated.

[0116] Specifically, the following are detailed embodiments:

[0117] Experimental Example 1:

[0118] The composition of butene was determined using the butene pretreatment device and gas chromatograph of this invention.

[0119] 1. Test instruments

[0120] Instruments: The butene pretreatment device and gas chromatograph of this invention.

[0121] Sample source: Commercially available standard gas prepared by a gas company, 80% 1-butene, 20% methane.

[0122] 2. Experimental Procedure

[0123] 1) Sample pretreatment

[0124] Connect the gas cylinder to the pretreatment unit, adjust the temperature knob to set the temperature to 150°C. The machine will then preheat. When the temperature sensor detects that the gas-liquid converter has reached the set temperature, the heater will automatically stop heating. Open the gas cylinder valve and adjust the knob to set the target pressure to 50 psi.

[0125] 2) Waste gas absorption

[0126] The switching valve is used to switch back and forth, replacing the gas in the pipeline. The replaced gas is then introduced into the waste gas treatment device through a conduit. After passing through a primary hydrocarbon removal device and a secondary hydrocarbon removal device, the sample adsorption is completed. The flow rate of the sample can be measured, and the value is read from the flow meter. Adjust the knob to set the exhaust air velocity to 18 m / s.

[0127] 3) Instrument parameter settings

[0128] a) Temperature program: Initial temperature 40℃, hold for 1 min, program temperature increase 7.5℃ / min, temperature 100℃, hold for 0 min, program temperature increase 15℃ / min, final temperature 190℃, hold for 20 min.

[0129] b) Carrier gas flow rate: 5 mL / min;

[0130] c) Inlet temperature: 200℃;

[0131] d) Split ratio: 20:1;

[0132] e) Detector temperature: 200℃;

[0133] f) Column flow rate: 5 mL / min;

[0134] g) Hydrogen flow rate: 35 mL / min;

[0135] h) Air flow rate: 300 mL / min;

[0136] Furthermore, the gas chromatograph is a flame ionization detector.

[0137] Furthermore, the chromatographic column 19095P-S23 has dimensions of 30m × 0.53mm × 15μm.

[0138] 3. Test Results

[0139] The content ω of each component in the sample i The percentage (volume fraction) is calculated using the following formula (1):

[0140]

[0141] In the formula: ω i —The content of component i in the sample as measured, in % (volume fraction);

[0142] A i —The measured peak area of ​​component i.

[0143] Table 1 Standard Gas Test Results

[0144]

[0145] Experimental Example 2:

[0146] The composition of butene was determined using the butene pretreatment device and gas chromatograph of this invention.

[0147] 1. Test instruments

[0148] Instruments: The butene pretreatment device and gas chromatograph of this invention.

[0149] Sample source: DX-1, an intermediate product of butene, from a domestic research institute.

[0150] 2. Experimental Procedure

[0151] 1) Sample pretreatment

[0152] Connect the gas cylinder to the pretreatment unit, adjust the temperature knob to set the temperature to 150°C. The machine will then preheat. When the temperature sensor detects that the gas-liquid converter has reached the set temperature, the heater will automatically stop heating. Open the gas cylinder valve and adjust the knob to set the target pressure to 50 psi.

[0153] 2) Waste gas absorption

[0154] The switching valve is used to switch back and forth, replacing the gas in the pipeline. The replaced gas is then introduced into the waste gas treatment device through a conduit. After passing through a primary hydrocarbon removal device and a secondary hydrocarbon removal device, the sample adsorption is completed. The flow rate of the sample can be measured, and the value is read from the flow meter. Adjust the knob to set the exhaust air velocity to 18 m / s.

[0155] 3) Instrument parameter settings

[0156] a) Temperature program: Initial temperature 40℃, hold for 1 min, program temperature increase 7.5℃ / min, temperature 100℃, hold for 0 min, program temperature increase 15℃ / min, final temperature 190℃, hold for 20 min.

[0157] b) Carrier gas flow rate: 5 mL / min;

[0158] c) Inlet temperature: 200℃;

[0159] d) Split ratio: 20:1;

[0160] e) Detector temperature: 200℃;

[0161] f) Column flow rate: 5 mL / min;

[0162] g) Hydrogen flow rate: 35 mL / min;

[0163] h) Air flow rate: 300 mL / min;

[0164] Furthermore, the gas chromatograph is a flame ionization detector.

[0165] Furthermore, the chromatographic column 19095P-S23 has dimensions of 30m × 0.53mm × 15μm.

[0166] 3. Test Results

[0167] The content ω of each component in the sample i The percentage (volume fraction) is calculated using the following formula (1):

[0168]

[0169] In the formula: ω i —The content of component i in the sample as measured, in % (volume fraction);

[0170] A i —The measured peak area of ​​component i.

[0171] Table 2 DX-1 Gas Test Results

[0172]

[0173]

[0174] Experimental Example 3:

[0175] The composition of butene was determined using the butene pretreatment device and gas chromatograph of this invention.

[0176] 1. Test instruments

[0177] Instruments: The butene pretreatment device and gas chromatograph of this invention.

[0178] Sample source: DX-2, an intermediate butene product from a domestic research institute.

[0179] 2. Experimental Procedure

[0180] 1) Sample pretreatment

[0181] Connect the gas cylinder to the pretreatment unit, adjust the temperature knob to set the temperature to 150°C. The machine will then preheat. When the temperature sensor detects that the gas-liquid converter has reached the set temperature, the heater will automatically stop heating. Open the gas cylinder valve and adjust the knob to set the target pressure to 50 psi.

[0182] 2) Waste gas absorption

[0183] The switching valve is used to switch back and forth, replacing the gas in the pipeline. The replaced gas is then introduced into the waste gas treatment device through a conduit. After passing through a primary hydrocarbon removal device and a secondary hydrocarbon removal device, the sample adsorption is completed. The flow rate of the sample can be measured, and the value is read from the flow meter. Adjust the knob to set the exhaust air velocity to 18 m / s.

[0184] 3) Instrument parameter settings

[0185] a) Temperature program: Initial temperature 40℃, hold for 1 min, program temperature increase 7.5℃ / min, temperature 100℃, hold for 0 min, program temperature increase 15℃ / min, final temperature 190℃, hold for 20 min.

[0186] b) Carrier gas flow rate: 5 mL / min;

[0187] c) Inlet temperature: 200℃;

[0188] d) Split ratio: 20:1;

[0189] e) Detector temperature: 200℃;

[0190] f) Column flow rate: 5 mL / min;

[0191] g) Hydrogen flow rate: 35 mL / min;

[0192] h) Air flow rate: 300 mL / min;

[0193] Furthermore, the gas chromatograph is a flame ionization detector.

[0194] Furthermore, the chromatographic column 19095P-S23 has dimensions of 30m × 0.53mm × 15μm.

[0195] 3. Test Results

[0196] The content ω of each component in the sample i The percentage (volume fraction) is calculated using the following formula (1):

[0197]

[0198] In the formula: ω i —The content of component i in the sample as measured, in % (volume fraction);

[0199] A i —The measured peak area of ​​component i.

[0200] Table 3 DX-2 Gas Test Results

[0201] Component 1st / % 2nd / % 3rd / % Ethylene 46.40 46.34 46.84 Butene 49.73 49.55 48.99 Hexene 3.48 3.52 3.62 Other substances 0.39 0.59 0.55

[0202] The composition of butene was determined using the butene pretreatment device and gas chromatograph of this invention. When the sample was prepared with gas from a commercially available standard gas company, containing 80% 1-butene and 20% methane, or with butene intermediate product DX-1 or DX-2 from a domestic research institute, good technical results could be achieved.

[0203] In summary, the butene pretreatment device provided by this invention processes butene using a pretreatment device. The pressurized butene is vaporized, resulting in complete and uniform vaporization of the components and accurate measurement results. Connecting the injection device to a gas chromatograph for sample composition analysis improves the efficiency of product analysis and the accuracy of sample measurement results in the production process. Gas chromatography analysis then accurately determines the butene content. This invention provides a rapid, efficient, and accurate butene pretreatment device and composition determination method, filling a technological gap in the relevant field and effectively solving the problems of uneven sample vaporization, unclean samples, and residual liquefied gas in the pipeline.

[0204] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A butene assay pre-treatment device, characterized by: It comprises: a sample injection system comprising a steel cylinder for containing a sample and a pretreatment injection device in communication therewith; a waste gas treatment system, the pretreatment injection device being located at the front end of the waste gas treatment system, the waste gas treatment system being connected with the pretreatment injection device through a switching valve and a pipeline; a detection system comprising a gas chromatograph and a gas source connected therewith, the pretreatment injection device being connected with the detection system; wherein the pretreatment injection device comprises a purification module, a heating module and a pressure reduction module connected in sequence, the purification module being connected with the steel cylinder, the heating module being arranged at the right side of the purification module, the pressure reduction module being arranged at the right side of the heating module, the pressure reduction module being connected with the waste gas treatment system and the gas chromatograph; the waste gas treatment system comprising an adsorption device, a gas collection part and a flow control part.

2. The butene measurement pretreatment apparatus according to claim 1, characterized by: The purification module comprises a primary filter and a secondary filter connected in sequence; the heating module comprises a gas-liquid converter, a heater and a temperature sensor connected in sequence; the pressure reduction module comprises a pipeline heat preservation sleeve and a pressure reduction valve, the pipeline heat preservation sleeve being connected with the pressure reduction valve through a pipeline at the left side and with the gas chromatograph through a pipeline at the right side.

3. The butene measurement pretreatment apparatus according to claim 2, characterized by: The gas-liquid converter is a heat conduction container, the heater provides a heat source for the gas-liquid converter, and the temperature sensor is used for sensing the temperature of the gas-liquid converter; the primary filter and the secondary filter are gas filters.

4. The butene measurement pretreatment apparatus according to claim 1, wherein: The pretreatment injection device further comprises a box, the box being provided with a pressure gauge and a temperature gauge, and further provided with control knobs for adjusting and controlling the temperature and pressure.

5. The butene measurement pretreatment apparatus according to claim 4, wherein: The box of the pretreatment injection device is further provided with a valve control knob, the valve control knob being capable of controlling two gears, one of which controls the connection of the pretreatment injection device with the detection system, and the other of which controls the communication of the pretreatment injection device with the waste gas treatment system.

6. The butene measurement pretreatment apparatus according to claim 1, wherein: The adsorption device in the waste gas treatment system comprises a primary hydrocarbon removal device, a secondary hydrocarbon removal device and an exhaust device connected in sequence; the gas collection part adopts a gas collection cylinder; the flow control part comprises a flow sensor, a pressure sensor and a flow integrator connected in sequence.

7. The butene measurement pre-treatment device according to claim 6, characterized in that: The adsorption device is connected with a gas source conduit, and the flow control part is connected to the upper portion of the gas source conduit.

8. The butene measurement pretreatment apparatus according to claim 6, wherein: The waste gas treatment system comprises a shell, the shell being provided with a control panel, the control panel being provided with a flow meter dial, a digital display module, a power-off power supply and a power-on power supply, and further provided with a wind speed control knob for adjusting the wind speed.

9. The butene measurement pretreatment apparatus according to claim 1, wherein: The gas chromatograph comprises a vaporization chamber, a chromatographic column, a detector, a column oven, an amplifier and a recorder connected in sequence.

10. A method of compositional determination, using a butene determination pretreatment device according to any one of claims 1 to 9, characterized in that: It comprises the following steps: appropriate pressure and temperature are set through the pressure gauge and the temperature gauge on the front surface of the pretreatment injection device, the temperature is adjusted to an appropriate temperature through the adjusting control knob; at this time, the heater starts heating, and when the temperature sensor detects that the temperature of the gas-liquid converter reaches the set temperature, the heater automatically stops heating; After the steel bottle sampling is connected to the left joint of the pretreatment sampling device, the steel bottle is opened, and the gas enters the heating module after passing through the first-stage filter and the second-stage filter; under the joint work of the heater and the temperature sensor, the sample is completely vaporized through the gas-liquid converter, the pressure is adjusted to the appropriate pressure through the adjustment control knob, and when the gas passes through the pressure reducing valve, the pressure is reduced to the normal pressure state; The valve control knob is used for back and forth switching to replace the gas in the pipeline, the replacement gas is introduced into the waste gas treatment system through the conduit, and the adsorption of the sample is completed through the first-stage hydrocarbon removal device and the second-stage hydrocarbon removal device; the sample flows through the flow sensor, the flow integrator, and the pressure sensor, and the flow size can be measured, the value is read out through the flowmeter dial, the air speed control knob is adjusted to control the air speed, and the value size is displayed by the digital display. The sample enters the gas chromatograph, the parameters of the instrument are set according to the chromatographic conditions, the sample passes through the chromatographic column, the components in the sample are separated due to the difference in the adsorption capacity of the components in the chromatographic column filler, the sample passes through the vaporization chamber, the detector, the amplifier, and the recorder, and the volume percentage of butene is calculated.

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