A pretreatment device for combustion conversion of organic chlorine in alkylated oil

Abstract

This utility model discloses a pretreatment device for the combustion conversion of alkylated oil with organochlorine, relating to the field of chemical analysis instruments. It includes a gas path control unit, a sample vaporization and delivery unit, a high-temperature decomposition unit, and a tail gas treatment unit. The gas path control unit includes a nitrogen supply component for providing carrier gas and an oxygen supply component for providing reaction gas. The sample vaporization and delivery unit includes a bubbler for holding the alkylated oil sample. The high-temperature decomposition unit includes a constant-diameter quartz tube inserted into a high-temperature carbon-fixing furnace. The tail gas treatment unit includes two tail gas absorption devices connected in sequence. The outlet of the nitrogen supply component is connected to the inlet of the bubbler. The outlets of the sample vaporization and delivery unit and the oxygen supply component are respectively connected to the inlet of the constant-diameter quartz tube in the high-temperature decomposition unit. The outlet of the constant-diameter quartz tube is connected to the inlet of the tail gas absorption device. This invention solves the problems of large carrier gas pressure fluctuation error, low organochlorine decomposition rate, and low acid gas purification rate in existing devices.

Description

Technical Field

[0001] This utility model belongs to the field of chemical analysis instruments, specifically relating to a pretreatment device for the organochlorine combustion conversion of alkylated oil. Background Technology

[0002] Alkylated oil, as an important petroleum product, has organochlorine content as a key indicator for evaluating product quality. The presence of organochlorine can corrode subsequent processing equipment and pipelines, affecting production safety and product quality. Therefore, accurately determining the organochlorine content in alkylated oil is of great significance. Currently, in existing technologies, the gas path of general-purpose organochlorine combustion conversion pretreatment devices often adopts a "single-stage pressure stabilization + single-stage flow stabilization" design, resulting in carrier gas pressure fluctuation errors exceeding ±10%, affecting sample delivery stability. The constant-diameter quartz tubes in the high-temperature decomposition unit often have a gradual diameter change problem, causing uneven gas flow rates and an organochlorine decomposition rate of less than 85%. Tail gas treatment often uses single-stage absorption, with acid gas purification rates below 80%, which not only pollutes the environment but also interferes with subsequent titration results, affecting the accuracy of subsequent analytical measurements and failing to meet the industrial requirements for precise detection of organochlorine in alkylated oil. Utility Model Content

[0003] To overcome the shortcomings of the prior art, the purpose of this utility model is to provide a pretreatment device for the combustion conversion of alkylated oil with organochlorine, which solves the problems of large carrier gas pressure fluctuation error, low organochlorine decomposition rate and low acid gas purification rate of the existing device.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: An alkylation oil organochlorine combustion conversion pretreatment device includes a gas path control unit, a sample vaporization and conveying unit, a high-temperature decomposition unit, and a tail gas treatment unit. The gas path control unit includes a nitrogen supply component for providing carrier gas and an oxygen supply component for providing reaction gas. The sample vaporization and conveying unit includes a bubbler for holding alkylation oil samples. The high-temperature decomposition unit includes a constant-diameter quartz tube inserted into a high-temperature carbon-fixing furnace. The tail gas treatment unit includes two tail gas absorption devices connected in sequence. The outlet of the nitrogen supply component of the gas circuit control unit is connected to the inlet of the bubbler of the sample vaporization and conveying unit. The outlet of the sample vaporization and conveying unit and the outlet of the oxygen supply component are respectively connected to the inlet of the equal-diameter quartz tube of the high-temperature decomposition unit. The outlet of the equal-diameter quartz tube is connected to the inlet of the tail gas absorption device.

[0005] Furthermore, the nitrogen supply assembly is sequentially connected to a nitrogen cylinder, a nitrogen pressure reducing valve, a nitrogen switching valve, a nitrogen pressure regulating valve, and a nitrogen flow regulating valve along the gas flow direction.

[0006] Furthermore, the oxygen supply assembly is sequentially connected to an oxygen cylinder, an oxygen pressure reducing valve, an oxygen switching valve, an oxygen pressure regulating valve, and an oxygen flow regulating valve along the gas flow direction.

[0007] Furthermore, the sample vaporization and delivery unit includes a bubbler placed inside an oil bath. The outlet of the nitrogen flow stabilizing valve is connected to the inlet of the bubbler, and the outlet of the bubbler is connected to one end of a one-way valve. The other end of the one-way valve is connected to the inlet of a quartz tube of equal diameter through the first inlet of a glass tee. The outlet of the oxygen flow stabilizing valve is connected to a rotor flow meter, and the outlet of the rotor flow meter is connected to the inlet of the quartz tube of equal diameter through the second inlet of a glass tee.

[0008] Furthermore, the high-temperature decomposition unit includes a high-temperature carbonization furnace, a constant-diameter quartz tube, and an electric heating controller. The constant-diameter quartz tube is inserted into the high-temperature carbonization furnace, and the electric heating controller is electrically connected to the high-temperature carbonization furnace.

[0009] Furthermore, the two sequentially connected exhaust gas absorption devices are each filled with an absorbent liquid for absorbing acidic gases in the exhaust gas.

[0010] Furthermore, the diameter of the equal-diameter quartz tube ranges from 8 to 12 mm, and the inner wall of the tube is coated with a high-temperature resistant inert coating with a coating thickness of 0.1 to 0.3 mm.

[0011] Furthermore, the heating temperature adjustment range of the oil bath is 50-180℃, and the temperature control accuracy is ±2℃.

[0012] Furthermore, the opening pressure of the one-way valve is 0.05-0.1 MPa.

[0013] Furthermore, the absorbent is a 0.2 mol / L sodium hydroxide solution.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: The gas path control unit of this invention adopts a four-stage series control structure for nitrogen and oxygen, combined with a rotor flow meter in the oxygen branch, to ensure precise control of the pressure and flow rate of nitrogen and oxygen, effectively reducing analytical errors caused by gas path fluctuations. The sample vaporization and delivery unit is placed in an oil bath via a bubbler, and with the coordinated design of a one-way valve with an opening pressure of 0.05-0.1 MPa, it achieves non-backflow delivery after sample vaporization, adapting to the vaporization requirements of different alkylated oils. The constant-diameter quartz tube of the high-temperature decomposition unit ensures uniform gas flow, and combined with a high-temperature carbon determination furnace with precise temperature control, it improves the decomposition efficiency of organochlorines, ensuring the accuracy of subsequent analytical results. The two-stage series tail gas absorption device can thoroughly purify the tail gas, protecting the environment and avoiding interference from the tail gas to the titration process. The overall device of this invention is designed specifically for the characteristics of alkylated oils, with a simple structure and convenient operation.

[0015] This invention, through the coordinated operation of units such as reasonable gas path control, sample vaporization and high-temperature decomposition, and tail gas treatment, can efficiently and accurately analyze and test the organochlorine content in alkylated oils. It is easy to operate and has good stability. It effectively solves the problems of gas path fluctuations, incomplete decomposition, and incomplete tail gas treatment in existing devices, providing a reliable analytical apparatus for the accurate determination of organochlorine content in alkylated oils. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; In the diagram, 1-Nitrogen cylinder; 2-Oxygen cylinder; 3-Nitrogen pressure reducing valve; 4-Oxygen pressure reducing valve; 5-Nitrogen switch valve; 6-Oxygen switch valve; 7-Nitrogen pressure regulating valve; 8-Oxygen pressure regulating valve; 9-Nitrogen flow regulating valve; 10-Oxygen flow regulating valve; 11-Bubbler; 12-Oil bath; 13-Check valve; 14-Rotameter; 15-Glass tee; 16-High-temperature carbonization furnace; 17-Equal diameter quartz tube; 18-Electric heating controller; 19-First tail gas absorption device; 20-Second tail gas absorption device. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments. The description is for explanation and not limitation of the present invention.

[0018] An alkylated oil organochlorine combustion conversion pretreatment device includes a gas path control unit, a sample vaporization and conveying unit, a high-temperature decomposition unit, and a tail gas treatment unit. Each unit is connected in series through corrosion-resistant pipelines to form a complete closed analytical flow path. The gas path control unit includes a nitrogen supply component for providing carrier gas and an oxygen supply component for providing reaction gas. Both the nitrogen supply component and the oxygen supply component are connected in series along the gas flow direction with a pressure reducing valve, a switching valve, a pressure regulating valve, and a flow regulating valve. The outlet of the flow regulating valve of the oxygen supply component is also connected in series with a rotor flow meter. Specifically, the gas circuit control unit includes a nitrogen cylinder 1 for storing nitrogen and an oxygen cylinder 2 for storing oxygen. The nitrogen cylinder 1 is sequentially connected to a nitrogen pressure reducing valve 3 for adjusting the cylinder's output pressure to the working pressure range, a nitrogen on / off valve 5 for manually controlling nitrogen flow, a nitrogen pressure regulating valve 7 for stabilizing nitrogen output pressure, and a nitrogen flow regulating valve 9 for precisely controlling nitrogen flow rate. The oxygen cylinder 2 is sequentially connected to an oxygen pressure reducing valve 4 for adjusting the cylinder's output pressure to the working pressure range, an oxygen on / off valve 6 for manually controlling oxygen flow, an oxygen pressure regulating valve 8 for stabilizing oxygen output pressure, and an oxygen flow regulating valve 10 for precisely controlling oxygen flow rate. The pressure reducing valve regulates the gas pressure, the on / off valve controls the gas flow, and the pressure regulating valve and flow regulating valve ensure stable gas pressure and flow rate.

[0019] Specifically, the sample vaporization and transport unit includes a bubbler 11 for holding the alkylated oil sample and carrying the sample vaporization with nitrogen bubbling, an oil bath 12 for heating the bubbler 11 to promote sample vaporization, and a one-way valve 13 for preventing gas backflow. The bubbler 11 is placed inside the oil bath 12, which heats the bubbler 11 to vaporize the alkylated oil sample. The heating temperature of the oil bath 12 is adjustable from 50 to 180°C, with a temperature control accuracy of ±2°C. The outlet of the nitrogen flow stabilizing valve 9 is connected to the bubbler... The inlet of device 11 is connected to nitrogen gas, which is introduced into the bubbler 11 to carry the vaporized sample. The outlet of bubbler 11 is connected to one end of one-way valve 13. The opening pressure of one-way valve 13 is 0.05-0.1MPa, which can effectively prevent the mixed gas from flowing back. The outlet of oxygen flow stabilizing valve 9 is connected to rotor flow meter 14 for accurate measurement of oxygen flow. The outlet of rotor flow meter 14 and the other end of one-way valve 13 are connected to the two inlets of glass tee 15. Oxygen and nitrogen carrying the sample are mixed at glass tee 15.

[0020] Specifically, the high-temperature decomposition unit includes a high-temperature carbon determination furnace 16 for providing a high-temperature environment, a constant-diameter quartz tube 17 for allowing the mixed gas and sample to pass through and undergo a decomposition reaction, and an electric heating controller 18 for controlling the temperature of the high-temperature carbon determination furnace 16. The constant-diameter quartz tube 17 is inserted inside the high-temperature carbon determination furnace 16, and the electric heating controller 18 is electrically connected to the high-temperature carbon determination furnace 16 to control its temperature, ensuring that the temperature inside the constant-diameter quartz tube 17 reaches a suitable high temperature for the decomposition of organochlorines. The outlet of the glass tee 15 is connected to one end of the inlet of the constant-diameter quartz tube 17, allowing the mixed gas carrying the sample to enter the constant-diameter quartz tube 17 for high-temperature decomposition. The diameter of the constant-diameter quartz tube 17 ranges from 8 to 12 mm, and its inner wall is coated with a high-temperature resistant inert coating with a thickness of 0.1 to 0.3 mm to reduce sample residue.

[0021] Specifically, the exhaust gas treatment unit includes a first exhaust gas absorption device 19 and a second exhaust gas absorption device 20 for absorbing and treating exhaust gas. The outlet of the equal-diameter quartz tube 17 is sequentially connected to the two exhaust gas absorption devices. The exhaust gas absorption devices are filled with absorbent liquid to absorb acidic and other exhaust gases produced by decomposition, thus preventing pollution. A suitable absorbent liquid, such as sodium hydroxide solution, can be selected according to the composition of the exhaust gas to effectively purify it.

[0022] This invention's gas path control unit employs a four-stage series control structure for nitrogen and oxygen, coupled with a rotor flow meter in the oxygen branch, to achieve precise and stable gas path parameters, providing a reliable gas source for sample processing. The sample vaporization and transport unit, via a bubbler placed in an oil bath, and in conjunction with a one-way valve with an opening pressure of 0.05-0.1 MPa, ensures non-backflow transport after sample vaporization, adapting to the vaporization requirements of different alkylated oils. The high-temperature decomposition unit uses uniform diameter quartz tubes to ensure uniform gas flow, combined with a precisely temperature-controlled high-temperature carbon determination furnace, improving the decomposition efficiency of organochlorine compounds. The exhaust gas treatment unit adopts a two-stage series absorption structure, allowing flexible selection of absorbent liquid to achieve thorough purification of exhaust gas and avoidance of titration interference. The synergistic effect of these innovative structures makes the device specifically suitable for the analysis of organochlorine compounds in alkylated oils, balancing accuracy and practicality.

[0023] The specific analysis and testing process of the alkylated oil organochlorine combustion conversion pretreatment device described in this utility model is carried out strictly according to the collaborative working logic of each functional unit of the device. The detailed steps are as follows: I. Preparations before analysis and testing Reagent preparation and calibration: First, prepare a 0.02 mol / L silver nitrate solution and accurately calibrate it using the silver nitrate standardization method to determine the accurate concentration of the silver nitrate solution, which will serve as the standard reagent for subsequent titration analysis. At the same time, add a 0.2 mol / L sodium hydroxide solution to the first tail gas absorption device 19 and the second tail gas absorption device 20 to absorb and treat the acidic tail gas generated during the test.

[0024] Sample preparation and apparatus connection: Accurately weigh 1.0 g of alkylated oil sample and add it to the bubbler 11 placed in the oil bath 12; follow the instructions in the appendix. Figure 1 The device structure shown completes the sealed connection of the gas path control unit, sample vaporization and delivery unit, high-temperature decomposition unit and exhaust gas treatment unit, ensuring that there is no gas leakage at each interface.

[0025] Instrument preheating settings: Connect the power supply to the oil bath 12 and the high-temperature carbonization furnace 16; set the reaction parameters through the control panel of the high-temperature carbonization furnace 16, set the target temperature to 850℃, control the heating rate to 10℃ / min, and maintain the temperature for 24 hours after heating from room temperature (20℃) to 850℃; start the heating button, and after the high-temperature carbonization furnace 16 heats up to the set temperature and stabilizes, it enters the test state.

[0026] II. Analysis and Testing Process Nitrogen system startup and pipeline purification: Open the gas source valve of nitrogen cylinder 1, and adjust the nitrogen pressure regulating valve 7 and nitrogen flow regulating valve 9 in sequence to stabilize the nitrogen pressure at 0.3MPa and control the flow rate at 100mL / min; the stable nitrogen gas flow passes through the bubbler 11, one-way valve 13, glass tee 15, equal diameter quartz tube 17, first tail gas absorption device 19 and second tail gas absorption device 20, on the one hand to remove the air in the entire pipeline, and on the other hand to fill the pipeline with inert nitrogen to avoid air interfering with the subsequent reaction.

[0027] Oxygen system startup and gas mixing: Open the gas source valve of the oxygen cylinder, and adjust the oxygen parameters through the oxygen pressure stabilizing valve 8 and oxygen flow stabilizing valve 10 set in series. First, stabilize the pressure at 0.3MPa, and then control the flow rate at 200mL / min. After the oxygen is accurately measured by the rotor flow meter 14, it enters the glass tee 15 and is fully mixed with the nitrogen gas flow carrying the alkylated oil sample to form a mixed gas that meets the reaction requirements.

[0028] Sample vaporization and high-temperature decomposition: Turn on the heating switch of the oil bath 12, set the heating temperature to 110℃, and start the heating program. The alkylated oil sample in the bubbler 11 is rapidly and stably vaporized by the oil bath heating method. The vaporized organic gas is carried by nitrogen and enters the glass tee 15 through the one-way valve 13. After being fully mixed with oxygen, it is introduced into the equal-diameter quartz tube 17. Since the equal-diameter quartz tube 17 is installed in the high-temperature carbon-fixing furnace 16 which has been preheated to 850℃, the organic chlorine in the mixed gas undergoes a full decomposition reaction under high temperature environment and is converted into inorganic chloride.

[0029] Tail gas treatment and content determination: The tail gas generated by high-temperature pyrolysis is discharged from the outlet of the equal-diameter quartz tube 17 and enters the first tail gas absorption device 19 and the second tail gas absorption device 20 in sequence. The acidic components (containing inorganic chlorides) in the tail gas are absorbed by 0.2 mol / L sodium hydroxide solution multiple times and converted into chloride salts. After the absorption is completed, 20 mL of absorption liquid is taken into an Erlenmeyer flask, 5 drops of 5% potassium chromate indicator are added, and titration is performed with silver nitrate solution of a predetermined concentration until a brick-red precipitate appears in the solution and does not fade within 30 seconds, which is the titration endpoint.

Claims

1. A pretreatment device for organochlorine combustion conversion of alkylated oil, characterized in that, It includes a gas path control unit, a sample vaporization and delivery unit, a high-temperature decomposition unit, and a tail gas treatment unit; the gas path control unit includes a nitrogen supply component for providing carrier gas and an oxygen supply component for providing reaction gas; the sample vaporization and delivery unit includes a bubbler (11) for holding alkylated oil samples; the high-temperature decomposition unit includes a constant-diameter quartz tube (17) inserted into a high-temperature carbon-fixing furnace; and the tail gas treatment unit includes two tail gas absorption devices connected in sequence. The outlet of the nitrogen supply component of the gas circuit control unit is connected to the inlet of the bubbler (11) of the sample vaporization and conveying unit. The outlet of the sample vaporization and conveying unit and the outlet of the oxygen supply component are respectively connected to the inlet of the equal diameter quartz tube (17) of the high temperature decomposition unit. The outlet of the equal diameter quartz tube (17) is connected to the inlet of the tail gas absorption device.

2. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 1, characterized in that, The nitrogen supply assembly is connected in sequence along the gas flow direction to a nitrogen cylinder (1), a nitrogen pressure reducing valve (3), a nitrogen switching valve (5), a nitrogen pressure regulating valve (7), and a nitrogen flow regulating valve (9).

3. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 2, characterized in that, The oxygen supply assembly is connected in sequence along the gas flow direction to an oxygen cylinder (2), an oxygen pressure reducing valve (4), an oxygen switching valve (6), an oxygen pressure regulating valve (8), and an oxygen flow regulating valve (10).

4. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 3, characterized in that, The sample vaporization and conveying unit includes a bubbler (11), which is placed in an oil bath (12). The outlet of the nitrogen flow stabilizing valve (9) is connected to the inlet of the bubbler (11). The outlet of the bubbler (11) is connected to one end of a one-way valve (13). The other end of the one-way valve (13) is connected to the inlet of a quartz tube (17) through the first inlet of a glass tee (15). The outlet of the oxygen flow stabilizing valve (10) is connected to a rotor flow meter (14). The outlet of the rotor flow meter (14) is connected to the inlet of the quartz tube (17) through the second inlet of the glass tee (15).

5. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 1, characterized in that, The high-temperature decomposition unit includes a high-temperature carbonization furnace (16), a constant-diameter quartz tube (17), and an electric heating controller (18). The constant-diameter quartz tube (17) is installed inside the high-temperature carbonization furnace (16), and the electric heating controller (18) is electrically connected to the high-temperature carbonization furnace (16).

6. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 1, characterized in that, The two sequentially connected exhaust gas absorption devices are each filled with an absorbent liquid for absorbing acidic gases in the exhaust gas.

7. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 1, characterized in that, The diameter of the equal-diameter quartz tube (17) ranges from 8 to 12 mm, and the inner wall of the tube is coated with a high-temperature resistant inert coating with a coating thickness of 0.1 to 0.3 mm.

8. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 4, characterized in that, The heating temperature adjustment range of the oil bath (12) is 50-180℃, and the temperature control accuracy is ±2℃.

9. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 4, characterized in that, The opening pressure of the one-way valve (13) is 0.05-0.1 MPa.

10. The alkylated oil organochlorine combustion conversion pretreatment device according to claim 6, characterized in that, The absorbent is a 0.2 mol / L sodium hydroxide solution.

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