CN113812667B

CN113812667B - Tobacco aroma component dry distillation extraction equipment and method

Info

Publication number: CN113812667B
Application number: CN202111137582.4A
Authority: CN
Inventors: 周国俊; 储国海; 胡安福; 蒋健; 夏倩; 汪华文; 吴键; 王骏; 肖卫强; 徐建
Original assignee: China Tobacco Zhejiang Industrial Co Ltd
Current assignee: China Tobacco Zhejiang Industrial Co Ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2023-05-05
Anticipated expiration: 2041-09-27
Also published as: CN113812667A

Abstract

The invention relates to a dry distillation extraction device and a dry distillation extraction method for tobacco aroma components, wherein the device comprises a tobacco raw material processing system, a cracking reaction system, a gas-solid separation system, a condensation system and an electric catching system; the tobacco leaves are pretreated by the tobacco leaf raw material treatment system to form tobacco leaf raw materials, and then the tobacco leaf raw materials are sent into the cracking reaction system; the tobacco leaf raw materials undergo rapid cracking reaction in the cracking reaction system to generate cracking products comprising cracking gas and coke, and the cracking products are sent to the gas-solid separation system; the pyrolysis product is sent to the condensing system after coke in the pyrolysis product is removed through the gas-solid separation system to obtain pyrolysis gas; the pyrolysis gas is sent to the electric capturing system after the liquid phase product is removed by the condensing system to obtain a gas phase product; the gas phase product passes through the electric catching system to obtain electric catching aerosol. The system and the method can collect the aerosol components which cannot be condensed in the carbonization pyrolysis gas.

Description

Tobacco aroma component dry distillation extraction equipment and method

Technical Field

The invention relates to a tobacco leaf processing device, in particular to a tobacco aroma component dry distillation extraction device and a tobacco aroma component dry distillation extraction method.

Background

The combustion process of tobacco is a very complex chemical reaction process, and the smoke contains the peculiar flavor of tobacco, mainly including phenols and nitrogen heterocyclic compounds (pyridine, pyrrole and pyrazine), and partial flavor components such as acids, aldehydes, ketones, alcohols, esters and the like. These flavor components are absent or present in minor amounts or in bound form in the tobacco itself, and are important flavor components in the smoke of cigarettes that affect the sensory enjoyment of the smoke. The students use thermal cracking-gas chromatography-mass spectrometry (PY-GC-MS), thermogravimetric analyzer (TG) and thermogravimetric-infrared-gas mass spectrometry (TG-IR-GC-MS) to study the combustion behavior of tobacco from different aspects. Li Qiaoling and the like utilize a thermal analyzer and a rapid tube type heating furnace to study the combustion behavior of tobacco shreds in an air atmosphere, and determine the release conditions of tar and acidic, neutral and alkaline flavor components under different temperature conditions. The results show that: tar and most of the aroma components are generated in large quantity when the combustion temperature reaches 350 ℃, and the release amount of the aroma components can show different rising or falling trends along with the continuous rising of the temperature.

The electronic cigarette provides a way for smokers to meet the smoking addiction of the smokers, and many electronic cigarettes are provided with various essences to increase the tobacco fragrance of the electronic cigarette, so that the essences have great harm to human bodies, and if the aroma components are extracted from the tobacco, the electronic cigarette has great significance for developing products such as the electronic cigarette.

At present, a method for extracting aroma components by dry distillation of tobacco has been proposed, and the method comprises the following steps: tobacco leaves are dried, crushed and screened to obtain raw materials for pyrolysis, the raw materials undergo a rapid pyrolysis reaction in a fluidized bed reactor at 100-800 ℃ to generate pyrolysis gas and coke, the coke in the products is removed through a primary cyclone separator and a secondary cyclone separator, and the pyrolysis gas is condensed through a primary condenser, a secondary condenser and a cyclone demister at the tail part to obtain aromatic liquid. However, in the scheme, tail gas is directly treated by a cyclone demister and discharged, and a large amount of available aerosol is not paid attention to in the tail gas.

Thus, there is a need for a tobacco aroma component dry distillation extraction apparatus and method to collect a significant amount of the available aerosol still present in the tail gas.

Disclosure of Invention

The invention aims to provide equipment and a method for dry distillation and extraction of tobacco aroma components, which collect aerosol components which cannot be condensed in dry distillation pyrolysis gas by using an electric catching system.

In order to solve the technical problems, the invention adopts the following technical scheme:

in a first aspect, the invention provides a dry distillation and extraction device for tobacco aroma components, which comprises a tobacco raw material processing system, a cracking reaction system, a gas-solid separation system, a condensation system and an electric catching system: the tobacco leaves are pretreated by the tobacco leaf raw material treatment system to form tobacco leaf raw materials, and then the tobacco leaf raw materials are sent into the cracking reaction system; the tobacco leaf raw materials undergo rapid cracking reaction in the cracking reaction system to generate cracking products comprising cracking gas and coke, and the cracking products are sent to the gas-solid separation system; the pyrolysis product is sent to the condensing system after coke in the pyrolysis product is removed through the gas-solid separation system to obtain pyrolysis gas; the pyrolysis gas is sent to the electric capturing system after the liquid phase product is removed by the condensing system to obtain a gas phase product; the gas phase product passes through the electric catching system to obtain electric catching aerosol.

By additionally arranging the electric catching system, a large amount of available aerosol components in the tail gas generated in the dry distillation and extraction process of the tobacco aroma components are fully recovered.

Further, the cracking reaction system includes a fluidized bed.

Further, the gas-solid separation system comprises a secondary cyclone separator.

Further, the gas-solid separation system further comprises a dust separator.

Further, the condensing system has a secondary condensing unit.

Further, the electric catching system comprises a first-stage electric catching and collecting tank, a second-stage electric catching and collecting tank;

the substances of the gas-phase aroma components collected by the first-stage electric trapping are first consistent aroma electric trapping liquid, and are collected in a first-stage electric trapping collecting tank; the residual gas phase aroma components are continuously sent into a second-stage electric catching device, and the collected substances are second aroma electric catching liquid and are collected in a second-stage electric catching collecting tank; still further, the first-stage electric trap and the second-stage electric trap both comprise electric traps and heaters, each electric trap comprises an electric trap cylinder and an electrode which axially penetrates through the electric trap cylinder, each electric trap cylinder is provided with an air inlet for allowing gas-phase aroma components to enter and an air outlet for discharging residual gas-phase aroma components, and each heater is used for heating the inside of each electric trap cylinder.

According to a second aspect, according to the foregoing extraction apparatus, there is provided a dry distillation extraction method of tobacco aroma components, comprising the steps of: the tobacco leaves are pretreated by a tobacco leaf raw material treatment system to form tobacco leaf raw materials, and then the tobacco leaf raw materials are sent to a cracking reaction system; the tobacco leaf raw materials undergo rapid cracking reaction in the cracking reaction system to generate cracking products comprising cracking gas and coke, and the cracking products are sent to a gas-solid separation system; the cracking product is sent to a condensing system after coke in the cracking product is removed by the gas-solid separation system to obtain the cracking gas; the pyrolysis gas is subjected to liquid phase product removal through the condensing system to obtain a gas phase product, and then the gas phase product is sent to the electric capturing system; the gas phase product passes through the electric catching system to obtain electric catching aerosol.

Further, the cracking reaction system includes a fluidized bed.

Further, the gas-solid separation system further comprises a dust separator.

Further, the condensing system has a secondary condensing unit.

In a third aspect, the invention further provides an electric aerosol prepared by the method for dry distillation and extraction of tobacco aroma components.

Further, the weight percent of dipentene, ethylcyclopentenulone, ionone, methylcyclopentenulone or guaiacol in the electrocapturing aerosol is greater than or equal to 1%.

In a fourth aspect, the invention applies the electrical aerosol-capturing device described above to an electronic cigarette liquid, an electrically heated tobacco product or a conventional cigarette; there may be a significant increase in the amount of smoke upon suction.

The invention designs a device and a method for dry distillation and extraction of tobacco aroma components, and utilizes an electric catching system to collect aerosol components which cannot be condensed in dry distillation pyrolysis gas, thereby realizing the following technical effects:

(1) A large amount of available aerosol components in the tail gas generated in the dry distillation and extraction process of the tobacco aroma components are fully recovered;

(2) Aromatic substances which cannot be collected by the traditional condensation process can be collected;

(3) Tail gas emission is reduced;

(4) The collected aerosol components have strong foggy property, and can be added into electronic cigarette liquid, electric heating tobacco products or traditional cigarettes to improve the smoke quantity during smoking.

(5) The collected electric aerosol is applied to novel tobacco products, so that burnt fragrance is highlighted, and the smoke characteristics of the traditional cigarettes are remarkably improved.

Drawings

The foregoing aspects of the invention and the following detailed description will be better understood when read in conjunction with the accompanying drawings. It should be noted that the drawings are only examples of the claimed technical solutions. In the drawings, like reference numbers indicate identical or similar elements.

FIG. 1 is a schematic diagram of the overall process of the tobacco dry distillation extraction of aroma components of the present invention;

FIG. 2 is a schematic diagram of a system for dry distillation extraction of aroma components from tobacco in accordance with the present invention;

FIG. 3 is a schematic diagram of the structure of the primary and secondary electric traps of the present invention;

FIG. 4 is a schematic diagram of the structure of the primary and secondary electric traps of the present invention;

FIG. 5 is a schematic diagram of the structure of the rectification system of the present invention;

FIG. 6 is a schematic diagram showing the temperature of each section of the rectifying tower with time;

FIG. 7 is a schematic diagram of the variation of the overhead composition over time;

FIG. 8 is a schematic diagram showing the effect of reflux ratio on pyridine mass fraction and recovery in overhead;

FIG. 9 is a reference graph showing the effect of reflux ratio on the composition of the pot liquid;

FIG. 10 is a tobacco raw material processing system of example 3 of the present invention;

FIG. 11 is a schematic diagram of a CO tail gas treatment system according to embodiment 2 of the present invention;

wherein reference numerals are as follows:

A. a first-stage storage bin; B. a second-level stock bin; C. an arch breaking machine; D. a feeder; E. a feeder; F. a fluidized bed; G. a primary cyclone separator; H. a first cyclone buffer tank; I. a primary cyclone storage tank; J. a secondary cyclone separator; K. a second cyclone buffer tank; l, two-stage cyclone storage tanks; m, high Wen Weichen separator; n, high Wen Weichen collection tanks; o, a first-stage condenser; p, a first-stage condenser collecting tank; q, second-stage condenser; r, a secondary condenser collection tank; s, first-stage electric catching; t, first-stage electric catching and collecting tank; u, second-stage electric catching; v, a second-stage electric catching and collecting tank; w, a tail gas treatment system; x, a preheater.

Detailed Description

The detailed features and advantages of the present invention will be readily apparent to those skilled in the art from that description, claims, and drawings.

As shown in fig. 1 and 2, the present invention provides a tobacco aroma component dry distillation extraction device, which comprises a tobacco raw material processing system, a cracking reaction system, a gas-solid separation system, a condensation system, a rectification system (not shown), an electric catching system and a tail gas processing system which are sequentially connected in series. Wherein:

the tobacco raw material treatment system comprises a first-stage storage bin A, a second-stage storage bin B, an arch breaking machine C, a feeder D and a feeder E, and can stably, continuously and quantitatively send tobacco raw materials into the cracking reaction system.

The cracking reaction system comprises a fluidized bed F and a preheater X, wherein the preheater X is arranged at the bottom of the fluidized bed F and is connected with N in the bottom ₂ The steel cylinders are communicated to heat the fluidizing gas and then introduce the heated fluidizing gas into the fluidized bed F for crackingAnd generating pyrolysis gas, wherein the pyrolysis temperature of the fluidized bed F is 100-400 ℃, and sending the pyrolysis gas into a gas-solid separation system to remove coke.

The gas-solid separation system comprises a first cyclone separator G, a first cyclone buffer tank H, a first cyclone storage tank I, a second cyclone separator J, a second cyclone buffer tank K, a second cyclone storage tank L, a high Wen Weichen separator M and a high-temperature fine dust collecting tank N. The first cyclone separator G and the second cyclone separator J are used for separating the gas-phase aroma components and coke in the pyrolysis gas step by step, and the high Wen Weichen separator M is used for continuously feeding the gas-phase aroma components after further removing trace solid impurities in the gas-phase aroma components. The high-temperature dust separator M can be a high-temperature electric catcher, a high-temperature ceramic filter, a high-temperature cloth bag filter and the like. The gas-solid phase product obtained by pyrolysis is separated by a primary cyclone separator G, a secondary cyclone separator J and a high-temperature dust separator M and then is respectively recovered in a primary cyclone buffer tank H and a primary cyclone storage tank I, a secondary cyclone buffer tank K and a secondary cyclone storage tank L and a high Wen Weichen collection tank N.

The condensing system comprises a primary condenser O, a primary condenser collecting tank P, a secondary condenser Q and a secondary condenser collecting tank R. The liquid phase substance generated after the gas-phase aroma components pass through the first-stage condenser O is first aroma condensate, and is collected in the first-stage condenser collecting tank P. The residual gas phase is continuously sent to a secondary condenser Q, the generated liquid phase is second aroma condensate, and the second aroma condensate is collected in a secondary condenser collecting tank R.

Further, the first aroma condensate and the second aroma condensate can be continuously sent into a rectification system for treatment; while the remaining gas phase aroma components can continue to be sent to the electrical capture system.

The electric catching system comprises a first-stage electric catching S, a first-stage electric catching collecting tank T, a second-stage electric catching U and a second-stage electric catching collecting tank V. The substances collected by the first-stage electric trapping S of the gas-phase aroma components are first consistent aroma electric trapping liquid and are collected in a first-stage electric trapping collecting tank T. The rest gas phase aroma components are continuously sent into a second electric catching U, the collected substances are second aroma electric catching liquid, and the second aroma electric catching liquid is collected in a second electric catching collecting tank V. And finally, the residual gas is sent to an exhaust gas treatment system W positioned at the tail part of the system.

Example 1 electric fishing System

The structures of the primary electric catcher and the secondary electric catcher need to enable the voltage to reach more than 30KV; illustratively, the present embodiment provides an electrical capture structure, the thermal capture device comprising an electrical trap and a heater 112; as shown in fig. 4, the electric catcher comprises an electric catcher cylinder 113 and an electrode 6 axially penetrating the electric catcher cylinder 113, referring to fig. 3, two ends of the electrode 6 are fixed at the upper and lower ends of the electric catcher cylinder 113 through insulation pieces 1,

the electric catching cylinder 113 is provided with an air inlet 111 for the gas-phase aroma components to enter and an air outlet 110 for the residual gas-phase aroma components to be discharged, specifically, the air outlet 110 is arranged above the electric catching cylinder 113, and the air inlet 111 is arranged below the opposite side of the electric catching cylinder 113;

the heater 112 is used for heating the interior of the electric catching cylinder 113; the heater 112 is capable of maintaining the temperature inside the electric trap cylinder 113;

the bottom of the electric catching cylinder 113 is communicated with a collecting tank 115 for collecting the aromatic electric catching liquid.

The upper end of the electric catching cylinder 113 is provided with a sealing cover plate 4 through a sealing connecting piece 5 (an upper flange) so as to ensure the tightness of the electric catching cylinder 113 and prevent air leakage. The upper ends of the electrodes are inserted into insulated terminals 3, and the insulated terminals 3 penetrate through the connecting piece 5 and the sealing cover plate 4; preferably, as shown in fig. 4, the upper end of the electrode is inserted into an insulating cover 1 made of corundum material 3, and an insulating terminal penetrates through the upper flange, so that good insulating performance is ensured; in order to ensure uniform electrostatic field distribution and improvement of trapping efficiency, the lower end of the electrode passes through a limiter made of corundum/ceramic and other materials, so that the electrode is always positioned in the middle of the electric trapping cylinder in long-time operation.

The lower end of the cylinder 113 is connected with the collection tank 115 in a sealing way through a sealing connection piece 2.

The electric catching cylinder body and the electrode are made of stainless steel materials.

After the reaction is finished, the heater is used for heating and maintaining the internal temperature range of the electric catching filter to be 500 ℃, air with a certain concentration is introduced for oxidation, after the electric catching filter is cleaned for 1 hour, coke residues are basically removed, the cleaning is finished, and generated carbon ash is collected in a carbon ash collecting tank to realize automatic cleaning.

The present example provides a dry distillation extraction method of tobacco aroma components, and illustratively, soft long-mouth tobacco leaves are dried at 80 ℃ for 1 hour, crushed and sieved to obtain raw materials with the particle size of 0.6 mm-2 mm. Pyrolyzing the raw materials at 425 ℃ by using a fluidized bed, wherein the feeding amount is 10kg/h, the fluidizing gas is nitrogen, the flow is 2.8m < 3 >/h, ash residues in the product are removed by a two-stage cyclone separator and a high-temperature dust separator, a first aroma condensate and a second aroma condensate are obtained by a two-stage water condenser, the first aroma condensate is more than the second aroma condensate, and the first condensate is rectified to obtain the final aroma condensate. The residual gas phase components are continuously sent into a two-stage electric catching system to obtain a first uniform electric catching liquid and a second electric catching liquid, and the first electric catching liquid and the second electric catching liquid are mixed to obtain a final electric catching liquid; under the action of a high-voltage power supply, the voltages of the electrodes and the grounding end of the primary electric trap and the secondary electric trap are kept at 30KV; the electric catching cylinder is heated by an external electric furnace to be kept at a preset temperature of 60 ℃.

The inventor of the invention respectively sends aroma condensate and electric liquid-catching to be analyzed, and the components are as follows:

table 1 fragrance imparting condensate composition:

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table 2 electrical liquid-catching composition:

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after comparing the contents of the main aroma compounds and aroma condensate in the electric trapping liquid, the following can be found:

TABLE 3 Table 3

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It can be seen from tables 1-3 that even after the second condensation, a significant amount of the nicotine component was still distributed in the aerosol in the remaining gas phase aroma components, and the nicotine component could be further collected by electrical capture.

In addition, aroma components such as dipentene, ethylcyclopentenolone, ionone, methylcyclopentenolone, guaiacol and the like cannot be collected by condensation, but can be further collected by electric capture.

Sensory evaluation

And respectively adding the electric trapping liquid and the aroma condensate prepared in the embodiment 1 as aroma components into a nicotine solution of the electronic cigarette, and performing sensory evaluation.

According to GB5606.4-2005 cigarette sensory quality evaluation standard and combining with electronic cigarette sensory characteristics, 6 evaluation indexes and scores are set according to different weights. The specific meanings are shown in Table 4:

TABLE 4 Table 4

And (5) statistics of evaluation results: according to the suction result of each expert, an arithmetic average value is obtained, one valid digit is reserved for the result, and the statistical result is shown in Table 5:

TABLE 5

Through the sensory evaluation, the aroma condensate is applied to novel tobacco products, the original aroma of the tobacco is increased in sensory sense, the characteristics of baking aroma and fumigating aroma are obvious, but the scorched smell and miscellaneous gas are slightly obvious, and the aroma is not clear enough.

The electric trapping liquid is applied to novel tobacco products, the original tobacco fragrance is obviously increased in sense, the burnt fragrance is pure, the fragrance is clear, the miscellaneous gas is lighter, the aftertaste is cleaner, and the applicability is stronger.

Example 2 rectification system

As shown in fig. 5, the embodiment provides a rectification system of tobacco dry distillation aroma condensate, which comprises a rectification tower, condensation modules (29-210) and fraction collection modules (212-214) which are connected in sequence. The rectifying tower comprises a tower kettle 21, a first tower section 26, a second tower section 27 and a tower top 28, wherein the tower kettle 21, the first tower section 26, the second tower section 27 and the tower top 28 are sequentially connected by tower section flanges from bottom to top;

the tower kettle is supported by the lifting furnace 22, so that the tower kettle 21 is convenient to assemble and disassemble; the tower kettle is provided with a temperature control module, a charging port 25, an air charging port 24 and a clean discharging port 23; the tower section is provided with a plurality of sections of temperature control modules;

the rectifying column has a reflux ratio controller 220;

the condensing module is provided with two stages of condensing units connected in parallel, and the condensing units comprise a condenser, low-temperature cold hydrazine, corresponding temperature, pressure and other control systems; specifically, the condensing module includes a primary condenser 29 and a primary low Wen Lengjing 211 connected in series, and a secondary condenser 210 and a secondary low Wen Lengjing 211 connected in series.

The fraction collection module comprises a front fraction tank 12, an intermediate product tank 13 and a product tank 14 which are sequentially connected from left to right, wherein the front fraction tank 12, the intermediate product tank 13 and the product tank 14 are provided with liquid level monitors, and products can be taken out timely as required through a pressure control system and valve control; the front fraction tank 12, the intermediate product tank 13, and the product tank 14 are each provided with a nitrogen-charging port 221, and an electronic balance 215; and the connection of each separation unit adopts standard connecting pieces with uniform size, so that the later size adjustment and replacement are convenient.

A secondary feeding valve can be added to the tower bottom to realize online feeding; the valve connection structure between the condensing module and the fraction collecting module and the pressure and liquid level control system of the collecting module can realize online discharging of fraction products in the collecting module, thereby realizing uninterrupted continuous operation of the rectifying link and improving the production efficiency.

Further, the rectification device further comprises a vacuum tank 218 and a vacuum pump 217 communicated with the vacuum tank 218, wherein the vacuum tank 218 is provided with a clean-out port 216 for discharging air, and the vacuum pump and the vacuum tank are communicated with a condensing system to clean out the air in the rectification system, so that anaerobic rectification is realized.

The distillation aroma condensate is placed in a tower kettle 1, and the distillate after rectification enters a distillate collecting module after condensation; the fraction collection module comprises a pressure and liquid level control system; the valve connecting structure between the condensing module and the collecting module and the pressure and liquid level control system of the collecting module can realize the online discharging of fraction products in the collecting module; the non-condensable gas enters a CO tail gas treatment system of the next unit.

As shown in fig. 11, the CO tail gas treatment system provided in this embodiment includes a gas preheater 61, a plate heat exchanger 61 and a catalytic chamber 63, where the gas preheater preheats and mixes the flue gas tail gas and air, and under the action of a fan, the flue gas tail gas and air enter the gas preheater along a pipeline to be preheated, then enter the plate heat exchanger to be oxidized and decomposed, then enter the catalytic chamber, then enter the plate heat exchanger, and finally be discharged. Furthermore, the invention adopts a simulation system to study the rectification condition; for the aroma condensate composition, a mimetic was used: pyridine, phenol, cyclopentanone, gamma-butyrolactone, nicotine, and their boiling points at normal pressure are shown in Table 6.

TABLE 6 boiling points of pure substances at atmospheric pressure for the simulants

Pyridine: cyclopentanone: phenol: gamma-butyrolactone: nicotine=1:1:1:1:2 (mass ratio) simulated oil 60g was formulated and added to the column bottoms. Heating is started, and condensed water is led in. When bubbles are generated in the kettle liquid, the upper section and the lower section of the tower body start to be heated;

slowly increasing the temperature of the tower kettle, regulating the temperature of the tower kettle when liquid reflux begins at the top of the tower, controlling reflux liquid, and starting timing and total reflux for 20min after the reflux liquid is stabilized;

after total reflux for 20min, opening a reflux ratio controller 220, and starting to extract products from the tower top; in the experimental process, the temperatures of the tower top, the tower kettle and the upper and lower sections of the tower body are recorded once every 10min, and meanwhile, the tower top distillate and the kettle liquid are sampled and analyzed.

The product composition was analyzed using an Agilent-7890B gas chromatograph. The model of the chromatographic column is HP-5, 30m multiplied by 320 mu m multiplied by 0.25 mu m, the automatic sample injection is carried out, the carrier gas is high-purity nitrogen, the sample injection amount is 1 mu L, and the split ratio is 30:1; the temperature of the sample inlet is 315 ℃, the detector is a hydrogen flame ionization detector, and the temperature is 310 ℃; column box programming temperature: the initial temperature is 60 ℃, kept for 2min, then raised to 150 ℃ at 3 ℃/min, then raised to 300 ℃ at 10 ℃/min, and kept for 1min; the tail blowing (nitrogen) flow is 25mL/min, the burning hydrogen flow is 30mL/min, and the combustion air flow is 400mL/min.

The quantitative calculation method of each component adopts a gas chromatography external standard method. The recovery rate of light pyridine in the overhead product is calculated according to the formula:

m-overhead mass, g; the mass fraction of pyridine in the omega-overhead in percent.

The reflux ratio r=8 and the column top vacuum degree of 0.092MPa are taken as an example, and the detailed experimental data are shown in tables 7 and 8.

TABLE 7 experimental data

Table 8 mass balance of each component

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From table 7, the mass fraction of pyridine as the overhead product was 65.47%, and the recovery rate= 6.4509/10.0213 =64.37%.

The mass fraction of pyridine in the original sample of the simulated oil is about 16.7%, the mass fraction of pyridine in the light component at the top of the tower after fractionation is enriched to 65.47%, and the enrichment effect of pyridine light components is remarkable.

As is clear from the mass balance in Table 8, there is a large difference in the front and rear masses of pyridine and cyclopentanone, which is caused by the liquid holdup of the rectifying column, i.e., the liquid is adhered to the inner wall of the rectifying column and the wire mesh packing, resulting in partial loss.

Temperature change of each section of the rectifying process tower along with time:

experiment under the condition that the vacuum degree of the tower top is 0.092MPa (the operation pressure is 9.3 KPa) and the constant reflux ratio R=8, the change rule of the temperature of the tower top, the upper section, the lower section and the tower kettle along with time in the rectification process is examined, and the result is shown in figure 1.

As can be seen from FIG. 6, the temperature of the tower is reduced from top to bottom in the whole rectification process, the temperature of the tower bottom is highest, and the temperature of the tower top is lowest. The temperature of each section of the tower is in an ascending trend along with the increase of time, and the distillate is continuously extracted along with the distillation, so that the light components in the whole system are continuously reduced, the heavy components are continuously enriched in the tower bottom, and the evaporation heat of the system is continuously increased. The temperature of each section of the tower is basically unchanged before 30min, the temperature starts to rise slowly after 30 min-50 min, the temperature rises quickly after 50min, and when 70min, the temperature of the tower top reaches 65 ℃ and the temperature of the tower bottom reaches 130 ℃.

Changes in overhead composition over time:

the effect of the rectification time on the mass fraction of pyridine and cyclopentanone in the overhead product was investigated at an overhead operating pressure of 9.3KPa, with reflux ratio r=8, and the results are shown in fig. 7.

As can be seen from fig. 7, the mass fraction of pyridine in the overhead decreases with time, and the tendency of the cyclopentanone mass fraction to change is reversed. The mass fraction of pyridine in the overhead product decreased more slowly before 50min, from 82.11% at 30min to 77.38% at 50min, after 50min, the decrease was severe, down to 63.25% at 70 min. The cyclopentanone mass fraction slowly increased from 17.20% at 30min to 21.82% at 50min and then rapidly increased to 35.54% at 70 min. This is because the distillate is continuously withdrawn as the operation time is prolonged, the content of the light key components in the still liquid is continuously reduced, and the distillation is carried out at a constant reflux ratio, i.e., the difficulty of separation is gradually increased, so that the concentration of the light key components in the distillate is continuously reduced.

Referring to FIG. 7, it was also found that 50min was an important time point, and that the overhead temperature and overhead composition varied significantly over time after 50 min. I.e., the change in the temperature of the overhead and the change in the composition of the overhead stream, are time dependent because the overhead stream, after condensation, is a distillate and has a different composition and a different dew point temperature (overhead temperature). Thus, the approximate change in distillate composition can be indirectly judged by observing the change in the temperature of the top of the column, which is advantageous for the control of the rectification operation.

Reflux ratio on the effect of light key component pyridine in distillate:

the reflux ratio is a very important process parameter in the rectification operation, and greatly influences the separation effect and the energy consumption. In general, the separation effect increases with the reflux ratio, but the cooling and heating loads of the column also increase.

The effect of reflux ratio on the mass fraction and recovery of light key component pyridine in the overhead was investigated under the conditions of 9.3KPa overhead pressure and 0.164 overhead recovery, and the results are shown in FIG. 8.

As can be seen from fig. 8, as the reflux ratio increases, both the mass fraction and recovery of the light key component pyridine in the overhead increases significantly. The mass fraction of pyridine is gradually increased from 52.14% at reflux ratio r=2 to 74.26% at r=14, and the recovery rate is increased from 51.35% to 75.39%. The increase is larger before the reflux ratio is less than 8 and is slower after the reflux ratio is less than 8, because the reflux ratio can be increased obviously when the reflux ratio is increased to a certain degree due to the limitation of the height of the fertilized distillation column. In actual production, the relation between the product quality and the energy consumption should be balanced to find the optimal reflux ratio.

Influence of reflux ratio on kettle liquid composition:

the results of the change in the composition of the pot liquid with the reflux ratio are shown in FIG. 9. As can be seen from FIG. 9, the content of pyridine in the kettle liquid is small, and the mass fraction of cyclopentanone is slowly increased from 4.23% to 8.25% as the reflux ratio is increased. Phenol is maintained at about 21.2%, gamma-butyrolactone is maintained at about 22.3% and fluctuates, and nicotine is at about 46%, mainly because of their very high boiling points, which remain in the tower, so the content is relatively stable.

The mass fraction of pyridine and cyclopentanone in the simulated oil is about 16.7%, the mass fraction of pyridine in the kettle liquid after rectification is reduced to below 5%, the mass fraction of cyclopentanone is reduced to below 8%, and the mass fraction of phenol, gamma-butyrolactone and nicotine is obviously increased, so that the effects of removing light components and enriching heavy components in the kettle liquid after rectification are obvious.

Actual pyrolysis oil fraction cut study:

separation of pyrolysis simulated oil by rectification was studied based on a laboratory small-sized rectification column. The temperature of each section of the tower body rises along with the increase of the rectifying time, and the tower bottom is more than the lower section and more than the upper section and more than the top of the tower. The mass fraction of the light-component pyridine in the tower top distillate is reduced along with the increase of the rectifying time, and the heavy-component cyclopentanone is opposite, because the light-component is continuously extracted from the tower top along with the progress of the rectifying, the heavy-component is continuously concentrated in the tower bottom, and the separating difficulty is gradually increased. The reflux ratio is gradually increased from 2 to 14 under other conditions, the mass fraction and the recovery rate of the light key component pyridine in the overhead product are both in an increasing trend, and at the reflux ratio of R=14, the mass fraction of pyridine is increased from 16.67% to 74.26% in the simulated oil, and the recovery rate is more than 75%.

The simulated oil separation result shows that the pyrolysis oil can be separated to a certain extent by using the rectification technology, certain components are purified and enriched, and the components are separated by adopting a fraction cutting method in consideration of the fact that the real pyrolysis oil is very complex in components, so that the purposes of dehydration and component removal are achieved, and then different fraction sections are respectively analyzed.

Rectification condition of aroma condensate

In the experiment, the vacuum degree of the tower top is 1KPa, the reflux ratio is an important technological parameter, the simulated oil separation research shows that the reflux ratio is increased, the separation effect is enhanced, the product purity is higher, the rectification time is correspondingly prolonged, the pyrolysis oil is a heat-sensitive substance, a series of problems such as aging and coking are aggravated when the heating time is too long in the tower kettle, the separation capability is limited when the reflux ratio is too small, and the reflux ratio R=5 is comprehensively considered. After several experiments on the aroma condensate, the appropriate cut parameters of the fractions were finally obtained as shown in table 9.

TABLE 9 results of cut experiments

Based on the above-mentioned research on distillation conditions, as a preferred example, the distillation conditions are: the heating temperature of the tower kettle is 120 ℃, the system pressure is 1KPa, and the tower section temperature is 60-80 ℃; reflux ratio control r=5; the condenser temperature is 25 ℃;

the dry distillation aroma condensate (0), the residue after rectifying in the column bottom, and the fraction of the collection module were analyzed by GC-MS, and the aroma components were obtained as shown in Table 10.

Table 10 comparison table of aroma components

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After rectification, the water content of the kettle liquid is reduced to 45.26% from 60.41% of the carbonization aroma condensate, and the enrichment of the scorch aroma, the smoke aroma and the baking aroma components in the kettle liquid can be seen from the table 1.

After the condensate is added into a novel tobacco product, a smoker performs sensory quality smoking according to GB5606.4-2005 and a Chinese style cigarette sensory evaluation method, so that the aroma is richer, the burnt aroma is purer, the dry burnt gas is reduced, the aroma characteristics different from the dry distillation aroma condensate and kettle liquid are realized, and the usability is stronger.

As shown in Table 11, the removal rate of at least 4 harmful components in the distilled kettle liquid is more than 50%, wherein the removal rate of phenol is 87.4%, and the removal rate of o-cresol and p-cresol is hundred percent.

Table 11 removal rate of harmful Components in the separated still solution

Example 3 tobacco raw Material processing System

The tobacco raw material processing system shown in fig. 10 is fed upstream from a feed inlet 31 to a tobacco raw material bin by means of a vacuum feeder. The tobacco raw material bin comprises at least one first-stage bin unit 311 and at least one second-stage bin unit 312.

The upstream of the first bin unit 311 is connected with a vacuum feeder, and the downstream of the second bin unit 312 is connected with a blanking device. The first-stage bin units 311 are connected in parallel, the second-stage bin units 312 are connected in parallel, and the first aggregate bin units 311 and the second-stage bin units 312 are connected in series. A bin valve 37 and a quick-opening feed port 38 are arranged between the first-stage bin unit 11 and the second-stage bin unit 312, and the bin valve can be an air pressure valve and further can be a pneumatic butterfly valve. When the vacuum feeding machine starts feeding, in order to make the feeding process smoothly proceed, a closed environment must be provided for the feeding end. If the blanking end is closed, the efficiency of downstream tobacco leaf treatment is reduced for a while, and the temperature and air pressure of the downstream tobacco leaf treatment are fluctuated, so that the quality of the tobacco leaf treatment is affected. Therefore, the tobacco raw material processing system designs a multi-stage bin system for feeding on-line on the premise of realizing continuous feeding.

The first bin unit 311 and the second bin unit 312 may be provided with a window 33 for observing the internal smoke condition. The window can be an oval plate frame viewing mirror, and the viewing mirror material can be high-strength toughened glass.

The first bin unit 311 and the second bin unit 312 are respectively provided with an arch breaker (a first-stage arch breaker 36 and a second-stage arch breaker 313). The arch breaker stretches into the inside of the bin unit and is linked with a motor (bridge breaking motor 35) outside the bin unit through a magnetic coupling device. The arch breaking machine comprises a main shaft and paddles which are arranged on the main shaft and have different lengths, positions and shapes, and the bridging of smoke is broken through the rotation of the paddles, so that the smooth feeding is realized.

The first bin unit 311 is provided with a bin level indicator or a bin level sensing device at the first-level feeding level 32 and the first-level discharging level 34, and the second bin unit 312 is provided with a bin level indicator or a bin level sensing device at the second-level feeding level 39 and the second-level discharging level 310, respectively, for monitoring the storage condition inside each bin unit. When the tobacco raw material level reaches a preset full bin position (feeding level), the vacuum blanking device or the pneumatic valve is controlled to control the upper-stage blanking unit to stop blanking, so that the raw material is prevented from overflowing. When the raw liquid material level reaches a preset empty bin position (blanking level), the vacuum blanking device or the air pressure valve is controlled to control the upper-stage blanking unit to start blanking, so that the raw materials are prevented from being empty.

The tobacco raw material in the second silo unit 311 can be stably, continuously and quantitatively fed into the screw type feeding device 316 fixed on the second bracket 319 by the screw type counter 314 fixed on the first bracket 315. In order to ensure that the tobacco raw materials fed into the feeding device 316 are not blown back to the metering device 314 due to the air flow generated by the high temperature and high pressure of the cracking reaction system, an air blowing module 317 can be arranged between the metering device 314 and the feeding device 316 for balancing the pressure in the storage bin. And meanwhile, a blanking view mirror 318 is arranged, so that blanking conditions can be observed at any time. In order to prevent the tobacco raw material pushed by the feeding device 316 from blocking the pipeline due to high-temperature coking of the cracking reaction system, a water jacket 320 may be disposed at the connection between the discharge port 324 of the feeding device 316 and the furnace body 323 of the cracking reaction system, and the water jacket 320 includes an outlet 321 and an inlet 322 for cooling water to prevent the high-temperature coking of the tobacco raw material.

In order to realize on-line vacuum feeding, the tobacco raw material treatment system supports a downstream carbonization fluidized bed, and the upstream and downstream of the tobacco raw material treatment system have an air pressure difference of 1-30 KPa.

Example 4 micronic dust separator

The dust separator employs an electrocatching structure as provided in example 1, running the example: after cyclone separation, the dry distillation product enters a high-temperature electric catcher through an air inlet; under the action of a high-voltage power supply, the voltages of the electrode and the grounding end are kept above 30KV; the electric catching cylinder is heated by an external electric furnace to be kept at a preset temperature (300-500 ℃); the dry distillation product mixed with a certain amount of fine carbon particles passes through an electric catching cylinder, and the carbon particles are combined with negative ions generated by ionization and are further adsorbed on an electrode to finish deposition and trapping. The grain diameter of the carbon particles obtained by electric catching is mainly distributed in the range of 0.1um-5 um. After static trapping is added, the content of solid products in the liquid products collected by the rear end condensation is greatly reduced from 0.39% to 0.042%.

The terms and expressions which have been employed herein are used as terms of description and not of limitation. The use of these terms and expressions is not meant to exclude any equivalents of the features shown and described (or portions thereof), and it is recognized that various modifications are possible and are intended to be included within the scope of the claims. Other modifications, variations, and alternatives are also possible. Accordingly, the claims should be looked to in order to cover all such equivalents. Also, it should be noted that while the present invention has been described with reference to the particular embodiments presently, it will be appreciated by those skilled in the art that the above embodiments are provided for illustration only and that various equivalent changes or substitutions may be made without departing from the spirit of the invention, and therefore, the changes and modifications to the above embodiments shall fall within the scope of the claims of the present invention as long as they are within the true spirit of the invention.

Claims

1. The equipment comprises a tobacco raw material processing system, a cracking reaction system, a gas-solid separation system, a condensation system and an electric capturing system, wherein the electric capturing system comprises a primary electric capturing device, a primary electric capturing collecting tank, a secondary electric capturing device and a secondary electric capturing collecting tank, the primary electric capturing device and the secondary electric capturing structure both comprise an electric capturing device and a heater, the electric capturing device comprises an electric capturing cylinder body and an electrode axially penetrating the electric capturing cylinder body, the electric capturing cylinder body is provided with an air inlet for gas phase products to enter and an air outlet for discharging residual gas phase products, the heater is used for heating the inside of the electric capturing cylinder body, and the voltages of the electrodes of the primary electric capturing device and the secondary electric capturing device and the grounding end are kept at 30KV; the electric catching cylinder is heated by an external electric furnace to be kept at a preset temperature of 60 ℃;

tobacco leaves are pretreated by the tobacco leaf raw material treatment system to form tobacco leaf raw materials, the tobacco leaf raw materials are sent to the pyrolysis reaction system, pyrolysis temperature is 100-400 ℃, the tobacco leaf raw materials undergo rapid pyrolysis reaction in the pyrolysis reaction system to generate pyrolysis products comprising pyrolysis gas and coke, the pyrolysis products are sent to the gas-solid separation system, the pyrolysis products are removed from the coke in the pyrolysis products through the gas-solid separation system to obtain pyrolysis gas, the pyrolysis gas is sent to the condensation system, the pyrolysis gas is subjected to the condensation system to remove liquid-phase products to obtain gas-phase products, and the gas-phase products are sent to the electric capture system, and the electric capture system is used for obtaining electric capture liquid.

2. The tobacco aroma component dry distillation extraction apparatus according to claim 1 wherein the pyrolysis reaction system comprises a fluidized bed.

3. The tobacco aroma component dry distillation extraction apparatus according to claim 1 wherein the gas-solid separation system comprises a secondary cyclone.

4. A tobacco aroma component dry distillation extraction apparatus according to claim 3 wherein the gas-solid separation system further comprises a dust separator.

5. The tobacco aroma component dry distillation extraction apparatus as claimed in claim 1, wherein the condensing system has a secondary condensing unit.

6. A method for dry distillation extraction of tobacco aroma components, using the equipment of any one of claims 1-5, comprising the following steps:

the tobacco leaves are pretreated by a tobacco leaf raw material treatment system to form tobacco leaf raw materials, and then the tobacco leaf raw materials are sent to a cracking reaction system;

the tobacco leaf raw materials undergo rapid cracking reaction in the cracking reaction system to generate cracking products comprising cracking gas and coke, and the cracking products are sent to a gas-solid separation system;

the cracking product is sent to a condensing system after coke in the cracking product is removed by the gas-solid separation system to obtain the cracking gas;

the pyrolysis gas is subjected to liquid phase product removal through the condensing system to obtain a gas phase product, and then the gas phase product is sent to the electric capturing system;

the gas-phase product passes through the electric catching system to obtain electric catching liquid.

7. An electrical liquid trap prepared by the method for dry distillation extraction of any one of the tobacco aroma components of claim 6.

8. The electro-capture of claim 7, wherein the electro-capture comprises greater than or equal to 1% by weight of dipentene, ethylcyclopentenolone, ionone, methylcyclopentenolone, or guaiacol.

9. Use of an electrical catch fluid according to claim 7 or 8 in an electronic cigarette liquid, an electrically heated tobacco product or a conventional cigarette.