Real-time On-line Analysis Device for Pyrolysis of Substances and Its Usage Method

Abstract

The present invention discloses a real-time on-line analysis device for pyrolysis of substances, comprising: a pyrolysis system (1), a trapping system (2), a testing system (3) and a control system (4); the pyrolysis system (1), the trapping system (2) and the testing system (3) are connected to the control system (4); the trapping system (2) has a cooling chamber (22) and a heating chamber (23), the temperature range of the cooling chamber (22) is from room temperature to -200°C, and the temperature range of the heating chamber (23) is from room temperature to 1000°C. The present invention also discloses a method for real-time on-line analysis of pyrolysis of substances using the device. The device of the present invention can provide real-time on-line pyrolysis, trapping, separation and analysis of substances at multiple temperature points or temperature ranges.

Description

Technical field

[0001] The present invention belongs to the technical field of detection, and particularly relates to a device and method for real-time on-line analysis of pyrolysis of substances. Background technique

[0002] When many inorganic and organic substances are heated to a certain extent, decomposition reactions will occur. There are many pyrolysis processes of organic substances with industrial significance, and they often have different names due to specific technological processes. The pyrolysis reaction carried out under anaerobic conditions is called dry distillation, such as coal dry distillation and wood dry distillation; the pyrolysis of methane to produce carbon black is called thermal decomposition; the pyrolysis of alkylbenzene or alkylnaphthalene to produce benzene or naphthalene is often called thermal dealkylation; the production of ketene from acetone is called acetone cracking, etc. The pyrolysis process of hydrocarbons is often distinguished as thermal cracking and pyrolysis. Understanding the product situation obtained during the pyrolysis process in real time and on-line is of great significance for controlling the reaction process, optimizing the reaction conditions, and changing the reaction substances. For example, tobacco is a biomass with complex components, and its pyrolysis products have a crucial impact on cigarette quality. Research shows that about 1 / 3 of the chemical components in cigarette smoke directly come from tobacco, and the rest are produced through a series of complex processes such as distillation, pyrolysis, combustion, and polymerization during the cigarette combustion process; therefore, it is necessary to establish an applicable pyrolysis model system for tobacco biomass and deeply study the pyrolysis laws and migration situations of various components of tobacco at any temperature.

[0003] The prior art mainly uses thermogravimetric analysis (TG / DTA) and flash pyrolysis (Py-GC / MS) to study the tobacco pyrolysis process. Flash pyrolysis (Py-GC / MS) mainly conducts rapid pyrolysis of substances at a single temperature point and then analyzes the pyrolysis products, and it is impossible to investigate the entire pyrolysis process of substances with temperature changes. For the hardly volatile substances in tobacco (such as sugars, amino acids, polyphenols, etc.), the pyrolysis products at a single temperature are obtained; it is difficult to discover the pyrolysis behavior of compounds at a specific temperature using this information. Moreover, the content of the pyrolysis products obtained by pyrolysis is very low, generally at the nanogram level, and even lower than the residual substances. When the pyrolysis products enter gas chromatography-mass spectrometry analysis, it will cause inaccurate qualitative and quantitative results.

[0004] Thermogravimetric analysis (TG / DTA) can provide stable reaction conditions under programmed temperature conditions and is the most ideal experimental tool for tobacco pyrolysis research. However, a single thermogravimetric analysis cannot obtain the specific substances and their contents during tobacco pyrolysis, and it must be combined with other methods to analyze the pyrolysis evolved components. At present, there is still a lack of an effective combined device for analyzing the pyrolysis evolved components, which severely restricts the application of thermogravimetric analysis in tobacco pyrolysis research. Currently, commercially available combined systems are still difficult to play a key role in tobacco pyrolysis research. The reasons are as follows: In the thermogravimetry-mass spectrometry (TG-MS) combination, the resolution of overlapping mass spectrometry peaks has not been achieved; in the thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR) or thermogravimetry-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS) combination, it is still difficult to identify compounds with the same functional groups, and the infrared peak collection is for the substances existing during the entire pyrolysis process of the material, and real-time substance collection at a certain temperature point or temperature range has not been realized. If existing technologies are used to study the pyrolysis of substances at any temperature point or temperature range, separate experiments need to be carried out by setting experimental conditions for that temperature point. For example, if the product content analysis of the entire pyrolysis process of a certain substance is to be carried out at 8 temperature points or temperature ranges, 8 separate experiments need to be carried out, which is time-consuming and laborious and causes waste of resources.

[0005] It has been reported that a six-way valve or an eight-way valve is used for switching to specifically capture pyrolysis substances for subsequent analysis. However, the evolved gas decomposed from the substance through heating has a certain temperature, and when the valve is switched at room temperature, it is extremely easy for the pyrolysis evolved substances to condense in the valve, causing pollution of the valve, and the substances captured may also be substances condensed from multiple experiments. Therefore, the analysis results are unreliable.

[0006] Online analysis of complex evolved components during the pyrolysis of substances at several temperature points or temperature ranges through a single experiment is a key problem that urgently needs to be solved in current substance pyrolysis research.

[0007] To solve the above problems, the present invention is proposed. Summary of the Invention

[0008] The present invention provides a device for real-time on-line analysis of substance pyrolysis. The capture system of this device has a cooling chamber and a heating chamber. The cooling chamber can condense and adsorb and capture pyrolysis products at a set temperature point or temperature range, and the heating chamber can heat the pyrolysis products for thermal desorption, and then perform real-time on-line separation and analysis.

[0009] The technical solution of the present invention is as follows:

[0010] The first aspect of the present invention discloses a real-time on-line analysis device for pyrolysis of substances, comprising: a pyrolysis system 1, a trapping system 2, a testing system 3 and a control system 4; the pyrolysis system 1, the trapping system 2 and the testing system 3 are connected to the control system 4, and the control system 4 controls the pyrolysis of substances, the trapping of pyrolysis products and the real-time separation and analysis of the entire device. There is a cooling chamber 22 and a heating chamber 23 in the trapping system 2. The temperature range of the cooling chamber 22 is from room temperature to -200 °C, and the temperature range of the heating chamber 23 is from room temperature to 1000 °C.

[0011] Preferably, the trapping system 2 includes the following components:

[0012] A horizontal moving groove 21;

[0013] A cooling chamber 22, arranged at one end of the horizontal moving groove 21; there is a cooling pipe 221 in the cooling chamber 22, and the cooling pipe 221 is connected to a cooling gas device 222; the cooling chamber 22 is hermetically connected to the pyrolysis system 1 through a gas pipeline 5; the length of the cooling chamber 22 is not less than the length of one collection tube 241;

[0014] A heating chamber 23, arranged at the other end of the horizontal moving groove 21; there is a heating pipe 231 in the heating chamber 23; the heating chamber 23 is hermetically connected to the testing system 3 through a gas pipeline 5; the length of the heating chamber 23 is not less than the length of one collection tube 241;

[0015] A rotary collector 24, which is arranged on the horizontal moving groove 21 between the cooling chamber 22 and the heating chamber 23, and can slide along the horizontal moving groove 21 in the direction of the cooling chamber 22 or the heating chamber 23, and the sliding distance is not less than the length of one collection tube 241; there are multiple collection tubes 241 on the rotary collector 24, and the multiple collection tubes 241 are arranged on the radius of the rotary collector 24; the rotary collector 24 can rotate 360° clockwise or counterclockwise;

[0016] A purging gas pipeline 25, which is connected to the rotary collector 24; the purging gas pipeline 25 is connected to a purging gas cylinder 251.

[0017] Preferably, the cooling gas device 222 contains liquid nitrogen, and the cooling temperature range is from room temperature to -200 °C; the temperature range of the heating pipe 231 is from room temperature to 1000 °C, and the heating rate range is 1 °C / s to 300 °C / s.

[0018] Preferably, the pyrolysis system 1 includes a pyrolysis device 11 capable of providing programmed temperature rise; a gas is introduced into the pyrolysis device 11 as a carrier gas, and the gas used as the carrier gas is one or more of air, nitrogen, oxygen, helium, and argon, and the gas flow rate is 0-2000 mL / min; the pyrolysis system 1 can collect the change programs such as its thermogravimetry, heat flow, and enthalpy in real time, and preferably select a comprehensive thermal analyzer; the pyrolysis system 1 can set multiple temperature points or temperature ranges according to the pyrolysis temperature of the substance, and its setting program is set by the control system 4.

[0019] Preferably, the test system 3 includes a separation device 31 and a detection device 32; one end of the separation device 31 is hermetically connected to the heating chamber 23 through a gas pipeline 5, and the other end is connected to the detection device 32.

[0020] Preferably, the separation device 31 includes, but is not limited to, a gas chromatograph; the detection device 32 includes, but is not limited to, a mass spectrometer.

[0021] Preferably, the purge gas in the purge gas pipeline 25 is one of nitrogen, helium, or argon; the gas flow rate is 0-2000 mL / min.

[0022] Preferably, the number of the collection tubes 241 is not less than eight.

[0023] The second aspect of the present invention discloses a method for real-time on-line analysis of substance pyrolysis. Using the aforementioned device, the method includes the following steps:

[0024] Place the substance to be analyzed in the pyrolysis device 11. When the programmed temperature rise reaches a set temperature point or temperature range under the control of the control system 4, the substance is pyrolyzed by heating at this set temperature point or temperature range.

[0025] The rotary collector 10 moves along the horizontal moving groove 21 towards the cooling chamber 22, and a collection tube 241 carried by it is completely inserted into the cooling chamber 22. The pyrolysis products are carried into the collection tube 241 by the carrier gas, and the cooling tube 221 cools the carrier gas so that the pyrolysis products are condensed and adsorbed in the collection tube 241; after collecting the pyrolysis products at this temperature point or temperature, the collection tube 241 is rotated 180° by the rotary collector 10, and then moves along the horizontal moving groove 21 towards the heating chamber 23.

[0026] Completely insert the collection tube 241 containing the pyrolysis products into the heating chamber 23. The heating tube 231 heats the heating chamber 23, and the pyrolysis products condensed and adsorbed in the collection tube 241 are thermally desorbed by heating. The purge gas in the purge gas pipeline 25 sends them into the separation device 31. After separation by the separation device 31, the separated substances enter the detection device 32, and the detection device 32 performs on-line analysis on the pyrolysis products.

[0027] Then, pyrolysis is carried out on substances at other temperature points or temperature ranges; by repeating the above steps, real-time online analysis of the pyrolysis of substances at multiple set temperature points or temperature intervals can be achieved.

[0028] The present invention has the following beneficial effects:

[0029] 1. The device of the present invention can provide real-time online trapping, separation, and analysis of multiple temperature points or temperature ranges for the primary pyrolysis of substances. The device of the present invention can detect and analyze the real-time changes in the primary pyrolysis products of substances, including the changes in the content of pyrolysis products with temperature.

[0030] 2. The device of the present invention uses a cooling method to rapidly trap the pyrolysis products during the pyrolysis process of substances, and then performs separation and analysis through thermal desorption, realizing a fully enclosed integrated experiment and the entire process of programmed temperature pyrolysis, cold trap trapping, online thermal desorption, automatic injection, separation, and analysis. It can study the pyrolysis of substances at a slower heating rate, and can achieve qualitative and relative quantitative analysis of the components of pyrolysis products, obtaining the real-time change law of pyrolysis components.

[0031] 3. The present invention uses several rotatable collection tubes to perform cold trap trapping on the pyrolysis products of substances at several temperature points or temperature ranges, and then sends them into the separation system and detection system through high-temperature thermal desorption. The use of cold trap trapping effectively avoids the secondary reaction of pyrolysis products during the high-temperature process in the trapping stage. The use of high-temperature thermal desorption effectively avoids the condensation of pyrolysis products in the transfer pipe or switching valve during the analysis stage, greatly improving the reliability of trapping and analyzing substances and significantly improving the accuracy of the analysis method.

[0032] 4. While monitoring the pyrolysis law of substances, the device of the present invention can, by combining the kinetic study of the programmed temperature of the pyrolysis device, sort out and analyze the thermochemical reactions of substances, establish a thermochemical reaction model, and intervene in the pyrolysis chemical reaction from aspects such as controlling the reaction process, optimizing the reaction conditions, and changing the reaction substances, so as to realize the pyrolysis reaction proceeding in a beneficial direction under a controllable state. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the real-time online analysis device for the pyrolysis of substances of the present invention; the arrow direction in the pyrolysis system is the advancing direction of the carrier gas.

[0034] Figure 2 It is the thermogravimetry, heat flow, and thermogravimetric derivative diagram of tobacco material A of a certain brand of cigarette in Example 1.

[0035] Figure 3 It is the total ion current diagram of the pyrolysis substances of tobacco material A of a certain brand of cigarette in Example 1 heated to 31°C to 90°C.

[0036] Figure 4Figure showing the change in the content of main pyrolysis substances of tobacco material A of a certain cigarette brand in Example 1 as the temperature rises from 30°C to 900°C.

[0037] Figure 5 Thermogravimetry, heat flow and derivative thermogravimetry diagrams of tobacco material B of a certain cigarette brand in Example 2.

[0038] Figure 6 Total ion current diagram of main pyrolysis substances of tobacco material B of a certain cigarette brand in Example 2 as the temperature rises from 71°C to 120°C.

[0039] Figure 7 Figure showing the change in the content of main pyrolysis substances of tobacco material B of a certain cigarette brand in Example 2 as the temperature rises from 30°C to 600°C.

[0040] Figure 8 Total ion current diagram of main pyrolysis substances of tobacco material B of a certain cigarette brand in Comparative Example 2 as the temperature rises from 30°C to 600°C.

[0041] Reference numerals in the drawings are: 1, pyrolysis system; 11, pyrolysis device; 2, trapping system; 21, horizontal moving tank; 22, cooling chamber; 221, cooling pipe; 222, cooling gas device; 23, heating chamber; 231, heating pipe; 24, rotary collector; 241, collection pipe; 25, purge gas pipe; 251, purge gas cylinder; 3, test system; 31, separation device; 32, detection device; 4, control system; 5, gas pipeline. Detailed implementation manners

[0042] The present invention will be further described below through examples, but is not limited to these examples. For experimental methods where specific conditions are not indicated in the examples, they are usually carried out according to conventional conditions and the conditions described in the manuals, or according to the conditions recommended by the manufacturers. General equipment, materials, reagents, etc. can be obtained from commercial sources without special instructions. The raw materials required in the following examples and comparative examples are all commercially available.

[0043] As Figure 1 shown, the on-line real-time analysis device for material pyrolysis of the present invention includes: a pyrolysis system 1, a trapping system 2, a test system 3 and a control system 4; the pyrolysis system 1, the trapping system 2 and the test system 3 are connected to the control system 4, and the control system 4 controls the material pyrolysis, the trapping of pyrolysis products and the real-time separation and analysis of the entire device. There is a cooling chamber 22 and a heating chamber 23 in the trapping system 2. The temperature range of the cooling chamber 22 is from room temperature to -200°C, and the temperature range of the heating chamber 23 is from room temperature to 1000°C.

[0044] Among them, the capture system 2 includes the following components: a horizontal moving groove 21; a cooling chamber 22 arranged at one end of the horizontal moving groove 21; there is a cooling pipe 221 in the cooling chamber 22, and the cooling pipe 221 is connected to a cooling gas device 222; the cooling chamber 22 is hermetically connected to the pyrolysis system 1 through a gas pipeline 5; the length of the cooling chamber 22 is not less than the length of one collection tube 241; a heating chamber 23 arranged at the other end of the horizontal moving groove 21; there is a heating pipe 231 in the heating chamber 23; the heating chamber 23 is hermetically connected to the testing system 3 through a gas pipeline 5; the length of the heating chamber 23 is not less than the length of one collection tube 241; a rotary collector 24 arranged on the horizontal moving groove 21 between the cooling chamber 22 and the heating chamber 23, which can slide along the horizontal moving groove 21 in the direction of the cooling chamber 22 or the heating chamber 23, and the sliding distance is not less than the length of one collection tube 241; there are multiple collection tubes 241 on the rotary collector 24, and the multiple collection tubes 241 are arranged on the radius of the rotary collector 24. Preferably, there are no less than eight collection tubes 241; the rotary collector 24 can rotate 360° clockwise or counterclockwise; a purge gas pipe 25 connected to the rotary collector 24; the purge gas pipe 25 is connected to a purge gas cylinder 251.

[0045] Among them, the cooling gas in the cooling gas device 222 is liquid nitrogen, and the cooling temperature range is from room temperature to -200°C; the temperature range of the heating pipe 231 is from room temperature to 1000°C, and the heating rate range is from 1°C / s to 300°C / s.

[0046] Among them, the pyrolysis system 1 includes a pyrolysis device 11 capable of providing programmed temperature rise; a gas is introduced into the pyrolysis device 11 as a carrier gas, and the gas used as the carrier gas is one or several of air, nitrogen, oxygen, helium, and argon, and the gas flow rate is 0 - 2000 mL / min; the pyrolysis system 1 can collect the change programs such as its thermal weight loss, heat flow, and heat enthalpy in real time. Preferably, a comprehensive thermal analyzer is selected; the pyrolysis system 1 can set multiple temperature points or temperature intervals according to the pyrolysis temperature of the substance, and its setting program is set by the control system 4.

[0047] Among them, the testing system 3 includes a separation device 31 and a detection device 32; one end of the separation device 31 is hermetically connected to the heating chamber 23 through a gas pipeline 5, and the other end is connected to the detection device 32; preferably, the separation device 31 includes, but is not limited to, a gas chromatograph; the detection device 32 includes, but is not limited to, a mass spectrometer.

[0048] Among them, the purge gas in the purge gas pipe 25 is one of nitrogen, helium, or argon; the gas flow rate is 0 - 2000 mL / min.

[0049] The method for real-time on-line analysis of substance pyrolysis using the device of the present invention includes the following steps:

[0050] Place the substance to be pyrolyzed for analysis in the pyrolysis device 11. When the temperature is raised according to a program under the control of the control system 4 and reaches a set temperature point or temperature range, the substance is pyrolyzed when heated at this set temperature point or temperature range.

[0051] The rotary collector 10 moves along the horizontal moving groove 21 towards the cooling chamber 22, and completely inserts a collection tube 241 it carries into the cooling chamber 22. The pyrolysis products are carried into the collection tube 241 by the carrier gas, and the cooling tube 221 cools the carrier gas so that the pyrolysis products condense and adsorb in the collection tube 241; after collecting the pyrolysis products at this temperature point or temperature range, the collection tube 241 is rotated 180° by the rotary collector 10 and then moves along the horizontal moving groove 21 towards the heating chamber 23.

[0052] Completely insert the collection tube 241 containing the pyrolysis products into the heating chamber 23. The heating tube 231 heats the heating chamber 23, and the pyrolysis products condensed and adsorbed in the collection tube 241 are thermally desorbed when heated, and are sent into the separation device 31 by the purge gas in the purge gas pipe 25. After separation by the separation device 31, the separated substances enter the detection device 32, and the detection device 32 performs on-line analysis of the pyrolysis products.

[0053] Then, pyrolysis is performed on substances at other temperature points or temperature ranges; repeating the above steps can perform real-time on-line analysis of the pyrolysis of substances at multiple set temperature points or temperature ranges.

[0054] Example 1: Perform real-time on-line analysis of the pyrolysis of a certain brand of cigarette tobacco material A using the device of the present invention.

[0055] Before the pyrolysis analysis of the substance, the pyrolysis device 11 is maintained at 800 °C for 10 min to drain impurities in the pyrolysis device 11; weigh 5.00 mg of a certain brand of cigarette tobacco material A and place it in the pyrolysis device 11; the temperature increase program is: the initial temperature rises from 30 °C to 900 °C at a rate of 10 °C / min and is maintained for 10 min. Air is used as the carrier gas, and the carrier gas flow rate is 50 mL / min. The thermogravimetry, heat flow and thermogravimetric derivative plots of a certain brand of cigarette tobacco material A are as Figure 2 shown.

[0056] Combined with Figure 2 the main obvious thermogravimetric steps of the tobacco material, the collection program for sixteen temperature segments is shown in Table 1. Sixteen collection tubes are set, and sixteen groups of pyrolysis products are collected according to the temperature segments in the entire temperature increase program; liquid nitrogen is used to quickly cool the pyrolyzed substances in the collection tubes, and the cooling temperature is -80 °C.

[0057] Table 1 Number of collection tubes and temperature segments of tobacco material A

[0058]

[0059] After the collection of the sixteen pyrolysis products is complete, the collection tube is sent into the heating chamber for thermal desorption by rotating the collection device 360° and horizontally moving it. Nitrogen is used as the purge gas, and the gas flow rate and the thermogravimetric flow rate are kept consistent at 50 mL / min. The thermal desorption temperature increase program is started from room temperature and heated to 900°C at a rate of 20°C / s.

[0060] The separation device 31 is a chromatograph: the chromatographic column is a DB-5MS capillary column (30 m × 0.25 mm, 0.25 μm), the injection port temperature is 250°C; the carrier gas is helium; the flow rate is 0.8 mL / min; the injection volume is 1 μL; the split ratio is 5:1; the programmed temperature rise conditions are: the initial temperature is 50°C, held for 10 min, heated to 280°C at a rate of 10°C / min, and held for 10 min.

[0061] The detection device 32 is a mass spectrometer; the ion source is an EI source, the ion source temperature is 230°C; the solvent delay time is 7.5 min, the mass spectrometry scanning range is 30 - 450 amu; the electron energy is 70 eV; the detection method is full scan.

[0062] The total ion chromatogram of the pyrolysis substances of a certain brand of cigarette tobacco material A heated from 31°C to 90°C is as Figure 3 shown; the content change of the main pyrolysis products with temperature from 30°C to 900°C is as Figure 4 shown.

[0063] Thus, it can be seen that the device of the present invention can detect and analyze the real-time changes of pyrolysis products in a certain temperature range, including the content changes of pyrolysis products with temperature. The above effects cannot be achieved by the prior art and have unique advantages.

[0064] Example 2: Use the device of the present invention for real-time on-line analysis of the pyrolysis of a certain brand of cigarette tobacco material B.

[0065] Before the pyrolysis analysis of the substance, the pyrolysis device 11 is maintained at 800°C for 10 min to drain the impurities in the pyrolysis device 11; 5.00 mg of a certain brand of cigarette tobacco material B is weighed and placed in the pyrolysis device 11; the temperature increase program is: the initial temperature is raised from 30°C to 600°C at a rate of 5°C / min and held for 10 min; air is used as the carrier gas, and the carrier gas flow rate is 40 mL / min. The thermogravimetry, heat flow and thermogravimetric derivative diagrams of a certain brand of cigarette tobacco material B are as Figure 5 shown.

[0066] Combined with Figure 5The cigarette tobacco material B has four thermogravimetric steps, and the weight loss ratio of each step is inconsistent: the weight loss is 3.6% at 30.3 - 106.3 °C, 17.9% at 106.6 - 219.3 °C, 44.2% at 219.3 - 392 °C, and 26% at 392.2 - 500 °C. The acquisition program for eight temperature segments is set as shown in Table 2, and eight acquisition tubes are set. The entire heating program acquires eight groups of pyrolysis products according to the temperature segments. Liquid nitrogen is used to rapidly cool the pyrolyzed substances in the acquisition tubes, and the cooling temperature is -40 °C.

[0067] Table 2 Number of acquisition tubes and temperature segments of tobacco material B

[0068]

[0069] After the acquisition of the eight pyrolysis products is complete, the acquisition tubes are sent into the heating chamber for thermal desorption through a 360° rotation and horizontal movement of the rotary collector. Nitrogen is used as the purge gas, and the gas flow rate and thermogravimetric flow rate are kept consistent at 40 mL / min; the thermal desorption heating program is started: starting from room temperature, heating to 900 °C at a rate of 10 °C / s.

[0070] The separation device 31 is a chromatograph: the conditions are: the chromatographic column is a DB-5MS capillary column (30 m × 0.25 mm, 0.25 μm), the inlet temperature is 250 °C; the carrier gas: helium; the flow rate is 0.8 mL / min; the injection volume: 1 μL; the split ratio: 5:1; the programmed temperature rise conditions: the initial temperature is 50 °C, held for 10 min, heated to 230 °C at a rate of 2 °C / min, and then heated to 250 °C at a rate of 10 °C / min, held for 10 min.

[0071] The detection device 32 is a mass spectrometer; the ion source is an EI source, the ion source temperature: 230 °C; the quadrupole temperature: 150 °C; no solvent delay, the mass spectrometry scanning range is 30 - 450 amu; the electron energy: 70 eV; the detection method: full scan.

[0072] Due to the use of the cold trap capture, thermal desorption and thermal purge of the present invention for the cigarette tobacco material B of this brand, a total of 83 pyrolysis products such as aldehydes and ketones, esters, organic acids, pyrazines, furanones, phenols, etc. are detected during the entire pyrolysis process. Among them, the total ion current diagram of the pyrolyzed substances at 71 °C - 120 °C is as Figure 6 shown; among the 83 pyrolysis products, nine representative substances with relatively large contents are selected, and the content change situation from 30 °C to 600 °C is as Figure 7 shown.

[0073] Therefore, it can be seen that by using the real-time online analysis device of the present invention, the pyrolysis products are trapped and analyzed according to the four main weight loss stages of thermogravimetry. The pyrolysis products of this tobacco material B are also mainly divided into four main regions. Region 1: Limonene is mainly pyrolyzed at 121-210 °C; Region 2: Nicotine and dinicotinic acid are mainly pyrolyzed at 211-230 °C; Region 3: 5-Methylfurfural, benzyl alcohol, and isomenthone are mainly pyrolyzed at 231-320 °C; Region 4: Benzoic acid, isoeugenol, and phytol are mainly pyrolyzed at 401-500 °C, that is, the main pyrolysis products in the maximum weight loss stage are benzoic acid, isoeugenol, and phytol.

[0074] Using the device of the present invention, it is clear from the process to the result what substances are the main pyrolysis products in the four main weight loss stages of this tobacco material B, and how these substances change with temperature. This cannot be achieved by the prior art.

[0075] Comparative example: Thermogravimetry-gas chromatography-mass spectrometry analysis of the prior art of tobacco material B of a certain brand of cigarette.

[0076] Before the pyrolysis analysis of the substance, the pyrolysis device 11 was maintained at 800 °C for 10 min to drain the impurities in the pyrolysis device 11; 5.00 mg of tobacco material B of a certain brand of cigarette was weighed and placed in the pyrolysis device 11; the temperature rising program was: the initial temperature was raised from 30 °C to 600 °C at a rate of 5 °C / min and maintained for 10 min; air was used as the carrier gas, and the carrier gas flow rate was 40 mL / min. The thermogravimetry, heat flow, and thermogravimetric derivative diagrams of tobacco material B of a certain brand of cigarette are as Figure 5 shown.

[0077] The pyrolysis products of the thermogravimetry were directly separated and analyzed by gas chromatography-mass spectrometry, and the total ion current diagram is as Figure 8 shown. The conditions were: the gas chromatograph and the mass spectrometer were the same as in Example 2; the pyrolyzed substances are shown in Table 3.

[0078] Table 3 All pyrolyzed substances of tobacco material B from 30 °C to 600 °C

[0079]

[0080] From Figure 5From the thermogravimetry, heat flow, and derivative thermogravimetry curves of the tobacco material B, it can be seen that the cigarette tobacco material B has four thermal weight loss steps, and the weight loss ratio of each step is different: 3.6% weight loss at 30.3 - 106.3 °C, 17.9% weight loss at 106.6 - 219.3 °C, 44.2% weight loss at 219.3 - 392 °C, and 26% weight loss at 392.2 - 500 °C. There is no obvious weight loss section for the tobacco material. Except for the relatively small weight loss rate in the first stage, the latter three stages are all maintained at 20 - 45%. This indicates that except for the first temperature section which may be due to the volatilization of moisture, a large amount of volatile substances are generated in the other three different temperature sections.

[0081] Using the prior art for thermogravimetry - gas chromatography - mass spectrometry analysis of the pyrolysis products of tobacco substances, all the pyrolysis substances in the entire pyrolysis process are transported into the GC / MS for analysis, and the total ion chromatogram of the entire pyrolysis process is obtained as Figure 8 shown, and the pyrolysis substances are shown in Table 3. Using the prior art thermogravimetry - gas chromatography - mass spectrometry analysis, many pyrolysis products have low contents, and are carried into the separation and detection system by the carrier gas during the pyrolysis process. Some pyrolysis products condense at various interfaces and pipelines of the system, and some pyrolysis products are lost to the lower limit of the detection limit when transported to the detection system, and the instrument cannot identify them. Therefore, only 23 substances are detected, which is much lower than the pyrolysis products detected by the present invention.

[0082] At the same time, the comparative example did not separately collect and analyze the pyrolysis products in the 4 weight loss stages, that is, the pyrolysis products in the 4 temperature sections, and it is impossible to obtain what the main pyrolysis products are in the four main weight loss stages of the substance and how these products change with temperature.

[0083] It can be seen from this that the prior art of the comparative example only focuses on the collection and analysis of all pyrolysis substances, and cannot collect and analyze the pyrolysis substances at any temperature point or temperature section, let alone monitor the change of the pyrolysis product content with temperature. However, the device of the present invention can detect and analyze the real - time change of the pyrolysis products at a certain temperature point or a certain temperature section, including the change of the pyrolysis product content with temperature. The above effects cannot be achieved by the prior art and have unique advantages. It can be seen that the technical advantages of the present invention are very obvious.

[0084] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above - mentioned embodiments. What is described in the above - mentioned embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An on-line real-time analysis device for pyrolysis of a substance, characterized in that, Comprising: A pyrolysis system (1), a trapping system (2), a testing system (3), and a control system (4); the pyrolysis system (1), the trapping system (2), and the testing system (3) are connected to the control system (4); inside the trapping system (2), there are a cooling chamber (22) and a heating chamber (23), the temperature range of the cooling chamber (22) is from room temperature to -200 °C, and the temperature range of the heating chamber (23) is from room temperature to 1000 °C; The trapping system (2) includes the following components: A horizontal moving groove (21); A cooling chamber (22) arranged at one end of the horizontal moving groove (21); inside the cooling chamber (22), there is a cooling pipe (221), and the cooling pipe (221) is connected to a cooling gas device (222); the cooling chamber (22) is hermetically connected to the pyrolysis system (1) through a gas pipeline (5); A heating chamber (23) arranged at the other end of the horizontal moving groove (21); inside the heating chamber (23), there is a heating pipe (231); the heating chamber (23) is hermetically connected to the testing system (3) through a gas pipeline (6); A rotary collector (24) arranged on the horizontal moving groove (21) between the cooling chamber (22) and the heating chamber (23), and it can slide along the horizontal moving groove (21) towards the direction of the cooling chamber (22) or the heating chamber (23); on the rotary collector (24), there are multiple collection pipes (241), and the multiple collection pipes (241) are arranged on the radius of the rotary collector (24); A purging gas pipeline (25) connected to the rotary collector (24).

2. The real-time online analysis device for pyrolysis of substances according to claim 1, wherein The cooling gas device (222) contains liquid nitrogen, and the cooling temperature range is from room temperature to -200 °C; the temperature range of the heating pipe (231) is from room temperature to 1000 °C, and the heating rate range is 1 °C / s to 300 °C / s.

3. The real-time on-line analysis device for pyrolysis of substances according to claim 1, characterized in that, The pyrolysis system (1) includes a pyrolysis device (11) capable of providing programmed temperature rise; a gas is introduced into the pyrolysis device (11) as a carrier gas, and the carrier gas is one or several of air, nitrogen, oxygen, helium, and argon, and the gas flow rate is 0 - 2000 mL / min.

4. The real-time on-line analysis device for pyrolysis of substances according to claim 1, characterized in that, The testing system (3) includes a separation device (31) and a detection device (32); one end of the separation device (31) is hermetically connected to the heating chamber (23) through a gas pipeline (5), and the other end is connected to the detection device (32).

5. The real-time online analysis device for pyrolysis of substances according to claim 4, characterized in that, The separation device (31) is a gas chromatograph; the detection device (32) is a mass spectrometer.

6. The real-time on-line analysis device for pyrolysis of substances according to claim 1, characterized in that, The purging gas in the purging gas pipeline (25) is one of nitrogen, helium, or argon; the gas flow rate is 0 - 2000 mL / min.

7. The real-time on-line analysis device for pyrolysis of substances according to claim 1, characterized in that The number of the collection pipes (241) is not less than eight.

8. A method for real-time on-line analysis of pyrolysis of a substance, characterized in that, Using the device according to any one of claims 1 - 7, includes the following steps: Placing the substance to be analyzed in the pyrolysis device (11), and when the programmed temperature rise reaches a set temperature point or temperature range under the control of the control system (4), the substance is pyrolyzed by heating at this set temperature point or temperature range. The rotary sampler (10) moves along the horizontal moving groove (21) towards the cooling chamber (22), fully inserts one sampling tube (241) it carries into the cooling chamber (22), and the pyrolysis products are carried into the sampling tube (241) by the carrier gas. The cooling tube (221) cools the carrier gas so that the pyrolysis products condense and adsorb in the sampling tube (241); after sampling the pyrolysis products at this temperature point or temperature range, the sampling tube (241) is rotated 180° by the rotary sampler (10), and then moves along the horizontal moving groove (21) towards the heating chamber (23); The sampling tube (241) containing the pyrolysis products is fully inserted into the heating chamber (23), and the heating tube (231) heats the heating chamber (23). The pyrolysis products condensed and adsorbed in the sampling tube (241) are thermally desorbed by heating, and are sent into the separation device (31) by the purge gas in the purge gas pipe (25). After separation by the separation device (31), the separated substances enter the detection device (32), and the detection device (32) performs on-line analysis of the pyrolysis products; Then, pyrolysis of substances at other temperature points or temperature ranges is carried out; by repeating the above steps, real-time on-line analysis of pyrolysis of substances at multiple set temperature points or temperature intervals can be achieved.

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