Patent Description:
Many inorganic and organic substances decompose when they are heated to a certain extent. Organic pyrolysis processes with industrial significance often have different names due to specific processes. Pyrolysis reaction in isolated air is called dry distillation, e.g., coal dry distillation and wood dry distillation; the process of methane pyrolysis to produce carbon black is called thermal decomposition; pyrolysis of alkylbenzene or alkylnaphthalene to produce benzene or naphthalene is often called thermal dealkylation; production of ketene from acetone is called acetone cracking. Pyrolysis process of hydrocarbons is often distinguished as thermal cracking and decomposition. Real-time online analysis of the products obtained during pyrolysis is of great significance for controlling reaction process, optimizing reaction conditions, and changing reaction substances. For instance, tobacco is a biomass with complex components, and its pyrolysis products have a crucial impact on cigarette quality. Studies show that <NUM>/<NUM> of chemical components in the smoke directly derive from tobacco, and the rest are produced in a series of complex processes such as distillation, decomposition, burning and polymerization during cigarette burning; thus, it is necessary to establish a model system suitable for tobacco biomass pyrolysis, and study pyrolysis and migration of tobacco components at any temperature.

The prior art mainly uses thermogravimetric-differential thermal analysis (TG/DTA) and pyrolyzer-gas chromatography mass spectrometry (Py-GC/MS) to study tobacco pyrolysis process. Py-GC/MS is mainly for rapid decomposition of substances at a temperature point, followed by analysis of pyrolysis products, it is impossible to investigate the whole process of pyrolysis of substances with temperature changes. For non-volatile substances in tobacco (e.g., sugars, amino acids, polyphenols, etc.), pyrolysis products at a single temperature are obtained; thus, it is difficult to recognize compound pyrolysis at a specific temperature with such information. Besides, since the content of pyrolysis products obtained by pyrolysis is low, generally at the nanogram level, even less than residual substances, as pyrolysis products go through gas chromatography-mass spectrometry analysis, there may exist qualitative and quantitative inaccuracies.

TG/DTA can provide stable reaction conditions during programmed heating, which is the most ideal experimental tool in tobacco pyrolysis research; however, specific substances and their content of tobacco pyrolysis cannot be obtained only by using TG/DTA, and other device must be combined to analyze thermogravimetric escaped components. However, there is still a lack of an effective combined device for analysis of thermogravimetric escaped components, thus seriously restricting application of thermogravimetric analysis in tobacco pyrolysis research. It is still difficult for the current commercially available combined systems to play a key role in tobacco pyrolysis research due to the following facts: thermogravimetric-mass spectrometry (TG-MS) has not yet realized analysis of overlapping peaks; it is difficult to identify compounds with the same functional groups by thermogravimetric analysis-Fourier transform infrared spectroscopy (TG-FTIR) or thermogravimetric analysis-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS), besides, substances existing in the whole substance pyrolysis process are collected at the infrared peak, real-time substance collection at a certain temperature point or segment cannot be achieved. In order to study substance pyrolysis at any temperature point or segment, it is necessary to set experimental conditions at certain temperature point to carry out separate experiments in the prior art, e.g., analysis of pyrolysis products and their content at eight temperature points or segments in the whole process requires eight experiments, which is time-consuming and a waste of resources.

It is reported that, by switching of six-way valve or eight-way valve, targeted pyrolysis products can be captured for subsequent analysis. However, the escaped gas decomposed by the substances has a certain temperature, and switching of the valve at room temperature can easily make escaped pyrolysis products to condense in the valve, causing pollution of the valve, the captured substances may also be those condensed after a plurality of experiments, thus analysis results are not reliable.

Publication <CIT> discloses a chromatographic enrichment and analysis system and method for trace and ultra-trace components. The system comprises a sample injection system (<NUM>), a vaporizing chamber (<NUM>), an enriching system (<NUM>), a heat preservation box (<NUM>), a sample collecting system (<NUM>), a focusing trap (<NUM>), a chromatographic analysis column system (<NUM>), a detector (<NUM>) and an electronic control system; the analysis method is characterized in that a sample enrichment working mode, a thermal desorption working mode and an analysis blowback working mode are completed through the combination of a four-way valve of the enriching system (<NUM>) and an electronic switch valve box (<NUM>). <CIT> relates to a device for studying the cracking process of cigarette additives, including: a thermogravimetric analyzer, a six-way valve, a cold trap and a gas chromatography/mass spectrometry (GC/MS) coupler; the six-way valves are I, II, III, IV, V, and VI in counterclockwise direction; the I is connected to the thermogravimetric analyzer; the II is connected to the end of the cold trap; the III is connected to the inlet port of GC/MS; the IV is the carrier gas inlet; the V is connected to the other end of the cold trap; the VI is the carrier gas outlet; this device has a wide range of applications and can be used both for solid additives and solid additives. No. III is connected to the inlet of the gas chromatograph/mass spectrometer; No. IV is the inlet of the carrier gas; No. V is connected to the other end of the cold trap; No. VI is the outlet of the carrier gas; the device has a wide range of applicability, which is applicable to the cracking of solid tobacco additives as well as the tobacco additives in the liquid form, and has a large sample loading capacity, is easy to be operated, and has a good reproducibility of the analytical results. The present discloses an application method for studying the cracking process of cigarette additives by using the above device. <CIT> relates to an apparatus for sequentially pyrolyzing a plurality of samples held in sample tubes, the apparatus comprising a substantially vertical passage through which tubes carrying the samples may be passed; an upper gas-tight valve for closing off the upper end of the passage; a lower gas-tight valve for holding a sample tube in the passage; a distribution valve directing purge gas and carrier gas to the top end of the passage and for passing pyrolyzed sample from the bottom of the passage to an analytical device; and an electrical heating element for heating the passage to temperatures at which a sample will be pyrolyzed.

Online analysis of complex escaped components of substance pyrolysis through a single experiment at several temperature points or segments is a key problem that needs to be solved urgently in the current substance pyrolysis research.

The present invention aims to solve the above-mentioned problems.

The present invention provides a real-time online analysis device for substance pyrolysis, the capturing system of the device has a cooling cavity and a heating cavity, the cooling cavity can condense and adsorb and capture pyrolysis products at the set temperature points or segments, the heating cavity can thermally desorb pyrolysis products, real-time online separation and analysis can be performed.

The technical solutions of the present invention are as follows.

The present invention relates to a real-time online analysis device for substance pyrolysis according to the attached claim <NUM>.

Preferably, the length of the cooling cavity <NUM> is no less than that of a collecting tube <NUM>.

Preferably, the length of the heating cavity <NUM> is no less than that of a collecting tube <NUM>.

Preferably, the sliding distance is no less than the length of a collection tube <NUM>. Preferably, the rotary collector <NUM> can rotate <NUM>°clockwise or counterclockwise.

Preferably, the purging gas pipe <NUM> is connected to the purging gas cylinder <NUM>.

Preferably, inside the cooling gas device <NUM> is liquid nitrogen, and the cooling temperature ranges from room temperature to -<NUM>; temperature of the heating tube <NUM> ranges from room temperature to <NUM>, and the heating rate range is <NUM>/ s ~ <NUM>/s.

Preferably, the pyrolyzing system <NUM> includes a pyrolyzing device <NUM> capable of providing programmed heating; gas is introduced into the pyrolyzing device <NUM> as carrier gas, which can be one or more of air, nitrogen, oxygen, helium, and argon, the gas flow rate is <NUM>~<NUM>/min; the pyrolyzing system <NUM> can collect substances during weight loss, heat flux, enthalpy and other programs in real-time; preferably, comprehensive thermal analyzer is selected; the pyrolyzing system <NUM> can set a plurality of temperature points or segments based on substance pyrolysis temperature, and the setting program is set by the controlling system <NUM>.

Preferably, the testing system <NUM> includes a separation device <NUM> and a detection device <NUM>; one end of the separation device <NUM> is in airtight connection with the heating cavity <NUM> through the gas pipeline <NUM>, and the other end is connected with the detection device <NUM>.

Preferably, the separation device <NUM> includes but is not limited to a gas chromatograph; the detection device <NUM> includes but is not limited to a mass spectrometer.

Preferably, the purging gas in the purging gas pipe <NUM> is one of nitrogen, helium or argon; the gas flow rate is <NUM>-<NUM> /min.

Preferably, the collection tubes <NUM> are no less than eight.

According to claim <NUM>, the present invention further relates to a method for real-time online analysis of substance pyrolysis by using the device mentioned above, including the following steps:.

List of signs in the drawings: <NUM>. A pyrolyzing system; <NUM>. A pyrolyzing device; <NUM>. A capturing system; <NUM>. A horizontal moving slot; <NUM>. A cooling cavity; <NUM>. A cooling tube; <NUM>. A cooling gas device; <NUM>. A heating cavity; <NUM>. A heating tube; <NUM>. A rotary collector; <NUM>. A collection tube; <NUM>. A purging gas pipe; <NUM>. A purging gas cylinder; <NUM>. A testing system; <NUM>. A separation device; <NUM>. A detection device; <NUM>. A controlling system; <NUM>. A gas pipeline.

The present invention is further illustrated below by the embodiments, but not limited to the embodiments. Experimental methods with no specific conditions in the embodiments, are usually in accordance with the conventional conditions and conditions described in the manual, or general equipment, materials, reagents, etc. used in the conditions recommended by manufacturers, unless otherwise specified, are available commercially. Raw materials required in the following embodiments and comparison are all commercially available.

A real-time online analysis device for substance pyrolysis as is shown in <FIG>, including: a pyrolyzing system <NUM>, a capturing system <NUM>, a testing system <NUM> and a controlling system <NUM>; the pyrolyzing system <NUM>, the capturing system <NUM> and the testing system <NUM> are connected with the controlling system <NUM>; the controlling system <NUM> controls pyrolysis of the entire device, capturing of pyrolysis products, and real-time separation and analysis, the capturing system <NUM> has a cooling cavity <NUM> and a heating cavity <NUM> inside, temperature of the cooling cavity <NUM> ranges from room temperature to -<NUM>, and temperature of the heating cavity <NUM> ranges from room temperature to <NUM>.

Wherein, the capturing system <NUM> includes the following components: a horizontal moving slot <NUM>; a cooling cavity <NUM> arranged at one end of the horizontal moving slot <NUM>; the cooling cavity <NUM> has a cooling tube <NUM>, which is connected with a cooling gas device <NUM>; the cooling cavity <NUM> is in airtight connection with the pyrolyzing system <NUM> through a gas pipeline <NUM>; the length of the cooling cavity <NUM> is no less than that of a collecting tube <NUM>; a heating cavity <NUM>, arranged at the other end of the horizontal moving slot <NUM>; the heating cavity <NUM> has a heating tube <NUM>; the heating cavity <NUM> is in airtight connection with the testing system <NUM> through the gas pipeline <NUM>; the length of the heating cavity <NUM> is no less than that of a collecting tube <NUM>; a rotary collector <NUM> arranged on a horizontal moving slot <NUM> between the cooling cavity <NUM> and the heating cavity <NUM>, which can slide along the horizontal moving slot <NUM> towards the cooling cavity <NUM> or the heating cavity <NUM>, the sliding distance is no less than the length of a collection tube <NUM>; a plurality of collecting tubes <NUM> are provided on a rotary collector <NUM>, and the plurality of collecting tubes <NUM> are arranged on the radius of the rotary collector <NUM>; preferably, the collection tubes <NUM> are no less than eight; the rotary collector <NUM> can rotate <NUM>° clockwise or counterclockwise; a purging gas pipe <NUM> is connected to the rotary collector <NUM>; the purging gas pipe <NUM> is connected to the purging gas cylinder <NUM>.

Wherein, inside the cooling gas device <NUM> is liquid nitrogen, and the cooling temperature ranges from room temperature to -<NUM>; temperature of the heating tube <NUM> ranges from room temperature to <NUM>, and the heating rate range is <NUM>/s ~ <NUM> /s.

Wherein, the pyrolyzing system <NUM> includes a pyrolyzing device <NUM> capable of providing programmed heating; gas is introduced into the pyrolyzing device <NUM> as carrier gas, which can be one or more of air, nitrogen, oxygen, helium, and argon, the gas flow rate is <NUM>~<NUM>/min; the pyrolyzing system <NUM> can collect substances during weight loss, heat flux, enthalpy and other programs in real-time, preferably, comprehensive thermal analyzer is selected; the pyrolyzing system <NUM> can set a plurality of temperature points or segments based on substance pyrolysis temperature, and the setting program is set by the controlling system <NUM>.

Wherein, the testing system <NUM> includes a separation device <NUM> and a detection device <NUM>; one end of the separation device <NUM> is in airtight connection with the heating cavity <NUM> through the gas pipeline <NUM>, and the other end is connected with the detection device <NUM>; preferably, the separation device <NUM> includes but is not limited to a gas chromatograph; the detection device <NUM> includes but is not limited to a mass spectrometer.

Wherein, the purging gas in the purging gas pipe <NUM> is one of nitrogen, helium and argon; the gas flow rate is <NUM>-<NUM>/min.

The method for real-time online analysis of substance pyrolysis by using the device of the present invention includes the following steps:.

Embodiment <NUM>: Real-time online analysis of pyrolysis of a cigarette brand tobacco material A by using the device of the present invention.

Before substance pyrolysis analysis, the pyrolyzing device <NUM> is kept at <NUM> for <NUM> to remove impurities in the pyrolyzing device <NUM>, weigh a cigarette brand of tobacco material A of <NUM> and place it in the pyrolyzing device <NUM>; the heating program is as follows: increase the initial temperature from <NUM>°Cto <NUM> at the rate of <NUM> /min, holding for <NUM>, the air is carrier gas, and gas flow is <NUM>/min. Thermogravimetric, heat flux and derivative thermogravimetric analysis of a cigarette brand tobacco material A are shown in <FIG>.

As is shown in <FIG>, the collecting program of sixteen temperature segments of main obvious thermal weight-loss steps of the tobacco material is shown in Table <NUM>, the collection tubes are set to sixteen, collect sixteen groups of pyrolysis products at various temperature segments during the whole heating program; liquid nitrogen is used to rapidly cool pyrolysis products in the collection tube at a cooling temperature of -<NUM>.

After sixteen pyrolysis products are completely collected, they are rotated <NUM>° by the rotary collector and moves horizontally, the collecting tube is fed into the heating cavity for thermal desorption, and nitrogen is used as purging gas, gas flow rate and thermogravimetric flow rate are consistent: <NUM>/min; start thermal desorption heating program: increase from room temperature to <NUM> at the rate of <NUM>/s.

The separation device <NUM> is chromatograph: chromatographic column is DB-<NUM> capillary column (<NUM> × <NUM>, <NUM>), inlet temperature is <NUM>; carrier gas is helium; flow rate is <NUM>/min; injection volume is <NUM>µL; split-flow ratio is <NUM>:<NUM>; heating program conditions are as follows: initial temperature is <NUM>, holding for <NUM>, increase to <NUM> at the rate of <NUM>/min, holding for <NUM>.

The detection device <NUM> is a mass spectrometer; ion source is EI source, ion source temperature is <NUM>; solvent delay time is <NUM>, mass spectrometry scanning range is <NUM>-450amu; electron energy is 70eV and detection method is full scan.

The total ion flow diagram of pyrolysis products of a cigarette brand tobacco material A heated to <NUM>~ <NUM> is shown in <FIG>, changes of main pyrolysis product content with temperature changes from <NUM>°Cto <NUM> are shown in <FIG>.

Thus, the device of the present invention can detect and analyze real-time changes of pyrolysis products within a certain temperature range, as well as changes of pyrolysis product content with temperature changes. The above effects cannot be achieved by the prior art, thus having unique advantages.

Embodiment <NUM>: Real-time online analysis of pyrolysis of a cigarette brand tobacco material B by using the device of the present invention.

Before substance pyrolysis analysis, the pyrolyzing device <NUM> is kept at <NUM> for <NUM> to remove impurities in the pyrolyzing device <NUM>, weigh a cigarette brand of tobacco material B of <NUM> and place it in the pyrolyzing device <NUM>; the heating program is as follows: increase the initial temperature from <NUM>°Cto <NUM> at the rate of <NUM> /min, holding for <NUM>, the air is carrier gas, and gas flow is <NUM>/min. Thermogravimetric, heat flux and derivative thermogravimetric analysis of a cigarette brand tobacco material B are shown in <FIG>.

As is shown in <FIG>, tobacco material B has four thermal weight-loss steps, weight-loss ratio of each step is inconsistent: <NUM>% for <NUM>~<NUM>, <NUM>% for <NUM>~<NUM>, <NUM>% for <NUM>~<NUM>, and <NUM>% for <NUM>~<NUM>. The collection program of eight temperature segments is shown in Table <NUM>, the collection tube is set to eight, collect eight groups of pyrolysis products at various temperature segments during the whole heating program. The pyrolysis products in the collection tube are rapidly cooled by liquid nitrogen at a cooling temperature of-<NUM>.

After completely collecting eight pyrolysis products, they are rotated <NUM>° by the rotary collector and move horizontally, feed the collection tube into the heating cavity for thermal desorption, using nitrogen as the purging gas, gas flow and thermogravimetric flow are consistent: <NUM>/min; start thermal desorption heating program: increase from room temperature to <NUM> at the rate of <NUM>/s.

The separation device <NUM> is chromatograph: the conditions are as follows: chromatographic column is DB-<NUM> capillary column (<NUM>×<NUM>, <NUM>), inlet temperature is <NUM>; the carrier gas is helium; the flow rate is <NUM>/min. injection volume is <NUM>µL and split-flow ratio is <NUM>:<NUM>; heating program is as follows: the initial temperature is <NUM>, holding for <NUM>, increase to <NUM> at the rate of <NUM> /min, then increase to <NUM> at the rate of <NUM>/min, holding for <NUM>.

The detection device <NUM> is a mass spectrometer; ion source is EI source, ion source temperature is <NUM>; quadrupole temperature is <NUM>; no solvent delay, mass spectrometry scanning range is <NUM>-450amu; electron energy is 70eV and detection method is full scan.

As to the cigarette brand tobacco material B, due to the use of cold-trap capture, as well as thermal desorption and thermal purge of the present invention, a total of <NUM> pyrolysis products including aldehyde ketones, esters, organic acids, pyrazines, furanones and phenols are detected during the whole pyrolysis process. Wherein, the total ion flow diagram of pyrolysis products at <NUM>~<NUM> is shown in <FIG>; nine representative substances with high content are selected from <NUM> pyrolysis products, the content changes from <NUM> to <NUM> are shown in <FIG>.

Therefore, it can be seen that pyrolysis products are captured and analyzed at four main weight-loss stages of thermogravimetric by using the real-time online analysis device of the present invention, pyrolysis products of tobacco material B include the following substances at four main regions: region <NUM>: limonene is mainly produced at <NUM>~<NUM>; region <NUM>: nicotine and nicotyrine are mainly produced at <NUM>~<NUM>; region <NUM>: <NUM>-methylfuranaldehyde, benzyl alcohol and isomenthone are mainly produced at <NUM>~<NUM>; region <NUM>: benzoic acid, isoeugenol and phytol are mainly produced at <NUM>~<NUM>, main pyrolysis products at the maximum weight-loss stage include benzoic acid, isoeugenol and phytol.

By using the device of the present invention, main pyrolysis products at four main weight-loss stages of the tobacco material B are determined from the process to the result, as well as their changes with the temperature. This cannot be achieved by the prior art.

Comparison: thermogravimetric-gas chromatography-mass spectrometry analysis of a cigarette brand tobacco material B of the prior art.

Before substance pyrolysis analysis, the pyrolyzing device <NUM> is kept at <NUM> for <NUM> to remove impurities in the pyrolyzing device <NUM>, a cigarette brand of tobacco material B of <NUM> is weighed and placed in the pyrolyzing device <NUM>; the heating program is as follows: increase initial temperature from <NUM>°Cto <NUM> at the rate of <NUM> /min, holding for <NUM>, the air is carrier gas, and carrier gas flow is <NUM>/min. Thermogravimetric, heat flux and derivative thermogravimetric analysis of a cigarette brand tobacco material B are shown in <FIG>.

The thermogravimetric pyrolysis products are directly separated and analyzed by gas chromatography-mass spectrometry. The total ion chromatogram is shown in <FIG>. The conditions are as follows: chromatograph and mass spectrometer, the same as embodiment <NUM>; pyrolysis substances are shown in Table <NUM>.

As is shown in <FIG>, tobacco material B has four thermal weight-loss steps, weight-loss ratios of each step are inconsistent: <NUM>% for <NUM>~<NUM>, <NUM>% for <NUM>~<NUM>, <NUM>% for <NUM>~<NUM>, and <NUM>% for <NUM>~<NUM>. Tobacco material does not have an obvious weight-loss stage. Except that weight-loss rate at the first stage is less, weight-loss rates at latter three stages are <NUM>-<NUM>%. It shows that, the first temperature segment may be volatilization of water, a large number of volatile substances generate at the remaining three temperature segments.

Pyrolysis products of tobacco substances are analyzed by thermogravimetric-gas chromatography-mass spectrometry of the prior art. All pyrolysis products of the whole pyrolysis process go through GC/MS analysis, the total ion flow of the whole pyrolysis process is shown in <FIG>, and pyrolysis products are shown in Table <NUM>. By using thermogravimetric-gas chromatography-mass spectrometry analysis of the prior art, pyrolysis products, due to low content and are brought by the carrier gas into the separation and detection system in the pyrolysis process, part are condensed at various interfaces and pipelines of the system, and part are lost to the lower point of the detection limit when they are transported to the detection system, making it difficult for the device to identify. Thus, only <NUM> substances are detected, much less than pyrolysis products detected by the present invention.

Meanwhile, the comparison does not respectively capture and analyze pyrolysis products at the four weight-loss stages, i.e., the four temperature segments, it is impossible to recognize main pyrolysis products at the four main weight-loss stages and changes of these products with temperature changes.

It can be seen that, comparison by using the prior art is only for capture and analysis of all pyrolysis substances, which cannot capture and analyze pyrolysis substances at any temperature point or segment, nor can it monitor changes of pyrolysis product content with temperature changes. However, the device of the present invention can be used to detect and analyze real-time changes of pyrolysis products at a certain temperature point or segment, as well as changes of pyrolysis product content with temperature changes. The above effects cannot be achieved by the prior art, thus having unique advantages. It can be seen that technical advantages of the present invention are obvious.

Claim 1:
A real-time online analysis device for substance pyrolysis, characterized in that, the device comprises: a pyrolyzing system (<NUM>), a capturing system (<NUM>), a testing system (<NUM>) and a controlling system (<NUM>); wherein:
the pyrolyzing system (<NUM>), the capturing system (<NUM>) and the testing system (<NUM>) are connected with the controlling system (<NUM>);
the capturing system (<NUM>) has a cooling cavity (<NUM>) and a heating cavity (<NUM>) inside, temperature of the cooling cavity (<NUM>) ranges from room temperature to -<NUM>, and temperature of the heating cavity (<NUM>) ranges from room temperature to <NUM>;
and wherein the capturing system (<NUM>) comprises the following components:
A horizontal moving slot (<NUM>);
A cooling cavity (<NUM>), arranged at one end of the horizontal moving slot (<NUM>);
The cooling cavity (<NUM>) has a cooling tube (<NUM>), which is connected with a cooling gas device (<NUM>); the cooling cavity (<NUM>) is in airtight connection with the pyrolyzing system (<NUM>) through a gas pipeline (<NUM>);
A heating cavity (<NUM>), arranged at the other end of the horizontal moving slot (<NUM>); the heating cavity (<NUM>) has a heating tube (<NUM>); the heating cavity (<NUM>) is in airtight connection with the testing system (<NUM>) through the gas pipeline (<NUM>);
A rotary collector (<NUM>) arranged on a horizontal moving slot (<NUM>) between the cooling cavity (<NUM>) and the heating cavity (<NUM>), which can slide along the horizontal moving slot (<NUM>) towards the cooling cavity (<NUM>) or the heating cavity (<NUM>); a plurality of collecting tubes (<NUM>) are provided on a rotary collector (<NUM>), and the plurality of collecting tubes (<NUM>) are arranged on the radius of the rotary collector (<NUM>);
A purging gas pipe (<NUM>) connected to the rotary collector (<NUM>).