A method for removing olefin components in cinnamon oil by ozonation and retaining cinnamaldehyde

Abstract

A method for removing olefin components in cinnamon oil by ozonation to retain cinnamaldehyde. The method uses the remaining components at the bottom of the distillation tower after the crude cinnamon oil containing cinnamaldehyde is distilled, namely, cinnamon oil as a raw material. Adding CaO, BaO, Ba(OH) 2 or Ca(OH) 2 As a catalyst, in a bubbling reactor, under normal pressure and 10 to 30° C., ozone is introduced for reaction for 0 to 120 minutes. The present invention can be used to oxidize olefin components other than cinnamaldehyde in cinnamon oil, laying a foundation for subsequent separation and recovery of cinnamaldehyde and benzaldehyde in cinnamon oil, thereby improving the utilization rate of crude cinnamon oil and realizing resource processing of waste liquid. The advantages of the present invention are that the catalyst used is non-toxic, harmless and environmentally friendly, olefin components are effectively removed, cinnamaldehyde is fully retained and the naturalness of cinnamaldehyde is maintained, and the composition of cinnamon oil is changed, which is conducive to the subsequent distillation separation of cinnamon oil and the recycling of cinnamaldehyde.

Description

Technical Field

[0001] The invention discloses a method for removing olefin components in cinnamon oil by ozonation to retain cinnamaldehyde, belonging to the field of forest chemical product processing. Background Art

[0002] Cinnamon oil is a volatile oil obtained by distillation of the bark, branches, and leaves of the Lauraceae plant Cinnamomum cassia Presl (Jiangxi Food Industry, 2010, (04): 43–46). Its main component is cinnamaldehyde, accounting for about 85–90wt%. Cinnamaldehyde is a natural organic compound with a special aroma, usually light yellow or yellow. It is used in the preparation of meat, condiments, oral care products, and chewing gum, etc. It has an antibacterial effect and can be added to aquatic products, meat products, etc. as a natural food preservative.

[0003] my country is a major producer of cinnamon oil, with an annual output of 2,000 tons of cinnamon oil, accounting for more than 90% of the global output (Biomass Chemical Engineering, 2020, 54(6): 18–24). To obtain cinnamon oil from cinnamon, it is first necessary to obtain crude cinnamon oil from cinnamon branches and leaves through steam distillation, and then obtain a series of products such as natural cinnamaldehyde, benzaldehyde, phenylpropionaldehyde, o-methoxycinnamaldehyde and cinnamyl acetate from the crude cinnamon oil through distillation (Modern Chinese Medicine Research and Practice, 2017, 31(05): 1673–6427). The remaining tail oil at the bottom of the distillation tower after distillation is called cinnamon oil.

[0004] Cinnamon oil is a yellow oily liquid, containing more than 50% cinnamaldehyde, and the remaining components are mostly olefin compounds. Although the polarity of the terpene components of cinnamon oil is smaller than that of cinnamaldehyde, their molecular weight is greater than that of cinnamaldehyde. This makes the boiling point of the terpene components in the oil very close to that of cinnamaldehyde, and it is difficult to separate them through distillation equipment. Therefore, before there is a suitable technology to recover cinnamaldehyde from cinnamon oil, companies producing cinnamon oil can only store it. And using storage to solve the problem of the continuous production of oil in cinnamon oil distillation is not a long-term solution. In the long run, it will occupy a lot of resources of the enterprise, increase production costs, and become a safety hazard. In order to solve the needs of related companies to recover cinnamaldehyde from cinnamon oil, turn waste into treasure, and make the most of natural resources, it is necessary to find an effective method to recover cinnamaldehyde from oil.

[0005] As an oxidant, ozone has the characteristics of high reaction efficiency and fast speed. At the same time, the oxygen generated after the ozone reaction can quickly leave the reaction system and will not remain in the reaction, and will not cause serious three-waste pollution problems. Therefore, ozone has been widely studied and applied in organic synthesis, inorganic synthesis and polymer synthesis. Ozone is often used to oxidize unsaturated olefin compounds and then decompose them into two smaller molecules - aldehydes and ketones (Journal of Guangxi University (Natural Science Edition), 1998, 23 (1): 54-56). Ozonation reacts quickly and can quantitatively cleave double bonds under mild conditions. In recent years, the research on combining the strong oxidizing property of ozone with catalysts has been increasing (CN201210008659.2, CN201510132197.9, CN201510959866.X, CN201710532001.4), the purpose of which is to improve the utilization rate of ozone and increase the reaction rate of the reaction, especially alkaline earth metal oxides or hydroxide catalysts can interact with aldehyde groups to convert them into covalent carboxylates, thereby protecting the aldehyde groups from being oxidized by ozone and obtaining better selectivity for generating benzaldehyde (CN202010072323.7). At present, there is only a method for producing food-grade benzaldehyde using cinnamon oil distillation bottom product (CN202120938532.X), but there is no report on the method of using alkaline earth metal oxides or hydroxides to catalyze ozone selective oxidation of cinnamon oil to remove olefin components and retain cinnamaldehyde. Therefore, the method of using alkaline earth metal oxides or hydroxides to catalyze ozone to selectively oxidize cinnamon oil to remove olefin components and retain cinnamaldehyde has broad application prospects, laying the foundation for the subsequent recycling of cinnamaldehyde in cinnamon oil, improving the utilization rate of cinnamon oil, and turning waste into treasure. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for removing olefin components in cinnamon oil and retaining cinnamaldehyde components, which is conducive to the subsequent recycling of cinnamaldehyde and benzaldehyde in cinnamon oil, thereby improving the utilization rate of cinnamaldehyde in crude cinnamon oil, turning cinnamon oil into treasure, and realizing the resource treatment of crude cinnamon oil distillation tail oil.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The invention discloses a method for removing olefin components in cinnamon oil by ozonation and retaining cinnamaldehyde. Barium oxide, calcium oxide, barium hydroxide or calcium hydroxide is used as a catalyst to selectively oxidize the cinnamon oil by heterogeneous catalytic ozone.

[0009] Further, the following steps are included:

[0010] Cinnamon oil and solvent are weighed respectively in a weight ratio of cinnamon oil: solvent = 1:1-3, the cinnamon oil and solvent are evenly mixed, and then placed in a reactor, barium oxide, calcium oxide, barium hydroxide or calcium hydroxide is added as a catalyst according to 1-10% of the mass of the cinnamon oil, ozone is introduced into the reactor, and a heterogeneous catalytic ozone selective oxidation reaction of the cinnamon oil is carried out.

[0011] Furthermore, the ozone flow rate is 300-600 mL / min.

[0012] Furthermore, the reaction is carried out under normal pressure and at -10 to 25°C.

[0013] Furthermore, the reaction time is 0 to 120 min.

[0014] Furthermore, the BaO, CaO, Ba(OH)2 and Ca(OH)2 catalysts after the reaction are washed, dried and reused.

[0015] Furthermore, the solvent is anhydrous ethanol.

[0016] Furthermore, the preparation method of the catalyst is as follows: dissolve the nitrate or chloride of barium or calcium metal in deionized water to prepare a solution with a concentration of 0.01 to 0.4 mol / L; similarly, dissolve ammonium bicarbonate in deionized water to prepare a solution with a concentration of 0.1 to 2.0 mol / L; add the prepared ammonium bicarbonate solution dropwise to the metal salt solution at a water bath temperature of 30°C and a rotation speed of 300 r / min by a co-current co-precipitation method, the solution changes from clear to turbid, and when the pH of the suspension is 7 to 8, stop adding the ammonium bicarbonate solution dropwise, and age the precipitate in the mother liquor at a constant temperature of 30°C for 1 to 10 hours, and then filter to obtain a precipitate; dry the obtained precipitate at 80°C for 12 to 24 hours to obtain Ba(OH)2 and Ca(OH)2 catalysts, and calcine Ba(OH)2 and Ca(OH)2 at a temperature of 300 to 900°C for 2 to 3 hours to obtain BaO and CaO catalysts.

[0017] Furthermore, the specific steps are as follows: 1-5g of cinnamon oil and 1-15g of anhydrous ethanol are mixed and placed in a bubbling reactor, the catalyst is added according to 1-10% of the mass of the cinnamon oil, and ozone is introduced into the bottom of the mixed liquid of the reactor at a flow rate of 300-600mL / min so that ozone can be fully utilized, and the cinnamon oil is subjected to heterogeneous catalytic ozone oxidation reaction for 0-120min under normal pressure and -10-25°C, so as to obtain the cinnamon oil with olefin components removed and most of cinnamaldehyde retained.

[0018] The invention discloses a method for selectively oxidizing cinnamaldehyde by heterogeneous catalysis ozone. The method comprises the following steps: respectively weighing cinnamaldehyde and anhydrous ethanol in a weight ratio of cinnamaldehyde to anhydrous ethanol = 1:1-3, mixing the cinnamaldehyde and anhydrous ethanol evenly, placing the mixture in a bubbling reactor, adding a catalyst in a weight ratio of 1-10% of the mass of cinnamaldehyde, introducing the ozone into the bottom of the mixed liquid of the reactor at a flow rate of 300-600 mL / min so that the ozone can be fully utilized, and carrying out a heterogeneous catalysis ozone oxidation reaction of cinnamon oil for 0-120 min under normal pressure and -10-25°C.

[0019] Furthermore, the catalyst is barium oxide, calcium oxide, barium hydroxide or calcium hydroxide.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In order to effectively utilize cinnamon oil, the inventor has established a method for removing olefin components in cinnamon oil by ozone to retain cinnamaldehyde, wherein cinnamon oil and solvent are mixed, placed in a bubbling reactor and a catalyst is added, and ozone is introduced to carry out ozonation reaction. Since cinnamon oil contains a large amount of cinnamaldehyde and terpenes with similar boiling points, the present invention is adopted to oxidize and remove terpenes in cinnamon oil through catalytic ozonation, and cinnamaldehyde is protected from excessive oxidation. Therefore, the application of the present invention can improve the utilization rate of cinnamon oil, and realize the resource processing of waste liquid, in order to achieve the maximum retention of cinnamaldehyde in cinnamon oil, which is conducive to subsequent separation and recovery of cinnamaldehyde in cinnamon oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XRD pattern of CaO prepared in the laboratory.

[0023] Figure 2 The schematic diagram of the ozonation reaction device includes an oxygen cylinder 1, a gas rotor flowmeter 2, an ozone generator 3, a low temperature constant temperature box 4, a bubble generator 5, and an exhaust gas treatment device 6.

[0024] Figure 3 This is the total ion chromatogram of GC-MS analysis of cinnamon oil.

[0025] Figure 4 The standard curve is used to calibrate the concentration of cinnamaldehyde.

[0026] Figure 5 The effect of reaction time on the cinnamaldehyde content in cinnamon oil by catalytic ozonation. Reaction conditions: ozone generation at a dry oxygen rate of 400 mL / min; 15.00 g of anhydrous ethanol, 5.00 g of cinnamon oil and 0.2 g of CaO catalyst; precooling to 0°C for 10 minutes; 120 min reaction time.

[0027] Figure 6Changes in the relative contents of cinnamaldehyde and olefin components during the ozonation of cinnamon oil.

[0028] Figure 7 This is the total ion chromatogram of GC-MS of the products after catalytic ozonation of cinnamon oil.

[0029] Figure 8 Effect of reaction time on the contents of olefins (a) and cinnamaldehyde (b) in cinnamon oil catalyzed by CaO ozonation.

[0030] Fig. 9 Changes in the contents of styrene (a) and cinnamaldehyde (b) in the mixed sample of styrene and cinnamaldehyde catalyzed by CaO ozonation.

[0031] Fig.10 This is the effect of catalyst dosage on the cinnamaldehyde content. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below through embodiments.

[0033] The invention discloses a method for removing olefin components in cinnamon oil by using ozone to retain cinnamaldehyde. The method uses cinnamon oil as raw material, BaO, CaO, Ba(OH)2 and Ca(OH)2 as catalysts, and adopts gas-solid-liquid three-phase catalytic ozone to selectively oxidize cinnamon oil.

[0034] Example 1

[0035] Weigh 20.00g of calcium nitrate tetrahydrate and dissolve it in deionized water to prepare a solution with a concentration of 0.4mol / L; similarly, weigh 18.97g of ammonium bicarbonate and dissolve it in deionized water to prepare a solution with a concentration of 1.2mol / L. At a water bath temperature of 30°C and a speed of 300r / min, the above prepared ammonium bicarbonate solution is added dropwise to the calcium nitrate solution by a co-current coprecipitation method. The solution changes from clear to turbid. When the pH of the suspension is 7-8, stop adding the ammonium bicarbonate solution. Wait for the precipitate to be aged at a constant temperature of 30°C in the mother liquor for 3h, and then filter it to obtain a precipitate. The obtained precipitate is dried at 90°C for 12h and calcined at 600°C for 2h to obtain a CaO catalyst. The X-ray powder diffraction (XRD) patterns of the samples were obtained using an X-ray diffractometer (SmartLab3KW, Bruker, Germany) with Cu-Kα radiation (40 kV, 40 mA, λ = 0.15406 nm) and a graphite monochromator, and compared with the XRD spectra of CaO and Ca(OH)2 ( Figure 1). Laboratory-prepared CaO exhibits obvious diffraction peaks at 2θ=32.2°, 37.3°, 53.8° and 64.1°. This is consistent with the signal of the calcium oxide standard diffraction card (PDF NO.37-1497). In addition, laboratory-prepared CaO also has diffraction peaks at 2θ=18.0°, 28.6°, 47.1° and 51.0°. When compared with the calcium hydroxide standard diffraction card (PDF NO.44-1481), it is confirmed to be the characteristic diffraction peak of Ca(OH)2. The reason is that during the XRD analysis, CaO reacted with H2O in the atmosphere, resulting in the partial conversion of calcium oxide into Ca(OH)2.

[0036] In the bubbling reactor, 5.00 g of cinnamon oil (cinnamaldehyde content of about 56.46%), 15.00 g of anhydrous ethanol, and 0.2 g of CaO catalyst were added respectively. The oxygen flow rate was adjusted to 400 mL / min, and oxygen entered the ozone generator (NPA39E-S, Shandong Lubang Optoelectronic Equipment Co., Ltd.) to generate ozone. Using o-dichlorobenzene as an internal standard, GC (GC-2018, Shimadzu, Japan) and GC-MS (QP2020, Shimadzu, Japan) were used to analyze the components of cinnamon oil before and after the reaction. The bubbling reaction device used in the study is as follows Figure 2 shown.

[0037] The device consists of six parts: oxygen cylinder, gas rotor flowmeter, ozone generator, low-temperature constant temperature box, bubble generator and exhaust gas treatment device.

[0038] The cinnamon oil used in the study was provided by Guangxi Gengyuan Spice Co., Ltd.

[0039] Ammonium bicarbonate (AR grade) and calcium nitrate tetrahydrate (AR grade) were purchased from Nanning Blue Sky Experimental Reagent Company.

[0040] Anhydrous ethanol (AR grade) and o-dichlorobenzene (LR grade) were purchased from Guangdong Fine Chemicals Engineering Technology Research and Development Center and Shanghai Jingchun Biochemical Co., Ltd., respectively.

[0041] Oxygen (99.9%) and nitrogen (99.999%) were purchased from Guangxi Ruida Chemical Technology Co., Ltd.

[0042] Helium (99.999%) was obtained from Nanning Air Separation Gas Research Co., Ltd.

[0043] Determination of cinnamaldehyde and olefin content during the reaction:

[0044] Before the ozonation reaction, take an appropriate amount of cinnamon oil, dilute it 10 times with anhydrous ethanol, and take 0.2μL for GC and GC-MS analysis. After the reaction, take an appropriate amount of product and filter it through a filter head (nylon, 13mm, 0.22μm), add 0.3g to a 10mL volumetric flask, and then add 1mL 0.002g / mL o-dichlorobenzene as an internal standard. Use anhydrous ethanol to make up to the scale, shake well, and use a chromatographic needle to measure a certain amount for GC analysis and GC-MS analysis.

[0045] GC analysis conditions: The gas chromatography column is a 30m×0.32mm×0.25μm AE.SE-54 capillary column, the column temperature is 160°C, the vaporization chamber temperature is 260°C, the hydrogen flame ionization detector (FID) temperature is 260°C, and the injection volume is 0.2μL.

[0046] GC-MS analysis conditions: The gas chromatography column is a DB-5MS quartz capillary column of 30m×0.25mm×0.25μm, the injection temperature is 230℃, the temperature is programmed, the initial temperature is 50℃, and the temperature is programmed: the initial temperature is 50℃, and then it is heated to 100℃ at a rate of 5℃ / min for 2min, and then heated to 200℃ at a rate of 10℃ / min, and maintained for 20min. The column flow rate is 1mL / min, the interface temperature is 250℃, and the ion source temperature is 200℃. Split automatic injection is used, the split ratio is 30:1, and the injection volume is 1μL.

[0047] Quantitative analysis: The cinnamaldehyde component with standard sample was quantified by internal standard standard curve method. 1.00 g of o-dichlorobenzene was accurately weighed in a 500 mL volumetric flask, and the volume was fixed with anhydrous ethanol as the internal standard. A cinnamaldehyde standard solution with a concentration of 0.08 g / mL was accurately prepared with anhydrous ethanol as the solvent. Five 10 mL volumetric flasks were numbered and diluted with anhydrous ethanol to a concentration of 0.06 g / mL, 0.04 g / mL, 0.02 g / mL, 0.01 g / mL and 0.002 g / mL of cinnamaldehyde standard solution. After shaking, the peak area ratio (x) was plotted against the concentration ratio (y). The regression equation was y=3.04265×x–0.12207, R 2 =0.99987; for terpenes without standard samples, their content was calculated using the area normalization method before and after the reaction.

[0048] The qualitative analysis results of the substances were retrieved from the electron ionization (EI) ion source mass spectrometry database (NIST EI-MS Library) published by the National Institute of Standards and Technology (NIST). The NIST database numbers used are NIST07, NIST08, NIST11, NIST14 and NIST21.

[0049] GC-MS total ion chromatography (TIC) of cinnamon oil is shown in Figure 3 . The relative content of each component in the figure was calculated by normalization method, and the results are listed in Table 1. There are 14 signals in total in the figure, and 10 of them were identified by database retrieval. Except for cinnamaldehyde with a content of 56.46%, the other 9 components are olefin compounds, with a total content of 38.37%. The difference between its boiling point and cinnamaldehyde is not obvious. The retention time of the signal in GC-MS analysis is within 6 minutes of cinnamaldehyde. The reason why cinnamaldehyde and olefins have similar boiling points and different molecular weights makes it impossible to separate and recover cinnamaldehyde from cinnamon oil.

[0050] Table 1 GC-MS analysis results of cinnamon oil

[0051]

[0052]

[0053] The experiment was repeated three times and Figure 4 The standard curve of cinnamaldehyde was obtained by GC determination using the internal standard method during the 120-minute experimental time. The change of cinnamaldehyde content is shown in Figure 2. Figure 5 The relative contents of cinnamaldehyde and olefin components were determined by GC-MS and analyzed according to the area normalization method. The results are shown in Figure 6 .

[0054] exist Figure 5 In the first 60 minutes of ozonation reaction of cinnamon oil, the cinnamaldehyde content remained basically unchanged, but after 60 minutes, the content decreased rapidly. Figure 6 The changes in the relative contents of cinnamaldehyde and olefin components in cinnamon oil further illustrate the specific reaction conditions in the two stages of the ozonation reaction of cinnamon oil. In the first 60 minutes, the olefin components in cinnamon oil were oxidized by ozone before cinnamaldehyde, and their content decreased rapidly. At 60 minutes, their content was close to zero. Due to the reduction of olefin components, the relative content of cinnamaldehyde increased from 56.46% to 80.48% in the first 60 minutes of the ozonation reaction. Figure 5 and 6 The data of the first 60 minutes show that in the ozone of cinnamon oil, olefin components undergo ozonation before cinnamaldehyde. In the latter part of the ozonation reaction, that is, after 60 minutes, since the olefin components in cinnamon oil have been completely oxidized, cinnamaldehyde begins to undergo ozonation. Figure 5 Its concentration drops rapidly.

[0055] Figure 7 This is the total ion flow chart of cinnamon oil after 60 minutes of ozonation reaction, and the sample was analyzed by GC-MS. The large amount of olefin components in cinnamon oil that were originally concentrated in 20 minutes have disappeared, and are replaced by a few scattered components. According to the detection of the NIST database, the components and contents of cinnamon oil after 60 minutes of ozonation reaction are shown in Table 2. The experimental results show that the use of CaO catalyzed ozone can selectively cause the olefin components in cinnamon oil to undergo ozonation reaction first. After 60 minutes of ozonation reaction, the olefin components in cinnamon oil can be removed, making it possible to recover cinnamaldehyde from the oil by distillation.

[0056] Table 2 GC-MS analysis results of cinnamon oil after catalytic ozonation reaction

[0057]

[0058] The role of CaO in the ozonation of cinnamon oil was studied. In the selective oxidation of cinnamaldehyde by ozone catalyzed by CaO, the role of the catalyst in improving the selectivity of benzaldehyde in the reaction was very obvious, mainly in three directions:

[0059] First, it reduces the activation energy of ozonation of the carbon-carbon double bond in cinnamaldehyde;

[0060] Second, it adsorbs ozone to form alkaline earth metal ozonides, and adsorbs aldehydes to form covalent carboxylates, which makes the aldehyde group lose its oxidizable properties and increases the activation energy of the over-oxidation reaction of benzaldehyde.

[0061] Third, decompose other strong oxidizing intermediates formed in the ozonation reaction to reduce excessive oxidation of benzaldehyde.

[0062] But in cinnamon oil containing olefin components, how do the above characteristics of CaO manifest themselves in a complex reaction system? Whether the amount of catalyst used in cinnamaldehyde is also optimal in ozonation of cinnamon oil also needs to be confirmed by experimental data.

[0063] (1) Under the experimental conditions of generating ozone at a dry oxygen rate of 400 mL / min and reacting at 0°C for 120 min, the results of ozonation of cinnamon oil with and without CaO were compared ( Figure 8), the results showed that the presence of catalyst CaO could reduce the content of olefin components in cinnamon oil more quickly and reduce the ozonation of cinnamaldehyde for a longer period of time.

[0064] (2) According to the ratio of olefins to cinnamaldehyde in cinnamon oil, styrene was used to replace the olefin components of cinnamon oil and mixed with cinnamaldehyde in a mass ratio of 2.8g:2.2g as a sample, and CaO-catalyzed ozone selective reaction was carried out. The results are as follows: Fig. 9 As shown. Fig. 9 The results show that the aldehyde group conjugated with the carbon-carbon double bond does affect the carbon-carbon double bond in cinnamaldehyde, making it rank after styrene in the order of ozonation reaction. However, the amount of CaO is not necessarily better. The effects of 0.1 and 0.3 g on styrene are basically the same; while for cinnamaldehyde, 0.2 g has the best catalytic effect.

[0065] (3) However, the ozonation data of cinnamon oil without catalyst and with 0.1–0.4 g CaO were compared ( Fig.10 ), some Figure 8 and 9 Different situations. Under the catalytic condition of 0.1g CaO, the cinnamaldehyde in cinnamon oil can be maintained for 100 minutes without a significant decrease, which is the longest time among all catalyst dosages. When the catalyst dosage increases, the retention time of cinnamaldehyde content in the ozonation reaction decreases to varying degrees. At 0.3g, the rate of decrease is the fastest. However, when the CaO dosage reaches 0.4g, its trend is similar to that of 0.2g.

[0066] The above experimental results show that the optimal amount of catalyst CaO in ozonation of cinnamon oil is different from the optimal amount in cinnamaldehyde. Excessive amount of catalyst is not conducive to maintaining the cinnamaldehyde content in cinnamon oil, so that it is quickly oxidized by ozone. The experiment was repeated to determine the relationship between the amount of catalyst and the cinnamaldehyde content in cinnamon oil. It is preliminarily judged that too much catalyst will increase the amount of adsorbed ozone, produce too much alkaline earth metal ozonide, increase the oxidant content, and accelerate the ozonation reaction.

[0067] The catalyst has the following effects on the reaction process:

[0068] First, ozone is adsorbed to form alkaline earth metal ozonides instead of being decomposed into hydroxyl radicals, so that overly strong oxidants will not be produced (hydroxyl radicals are the second strongest oxidants after fluorine).

[0069] Second, it reduces the activation energy of the olefin ozone reaction, making it easier to be oxidized.

[0070] Third, it adsorbs with the carbonyl group to form a covalent carboxylate, which makes it lose the ability to be oxidized (this can protect benzaldehyde or cinnamaldehyde).

[0071] Fourth, decompose the highly oxidizing reaction intermediates generated after the ozonation reaction to protect aldehyde substances from excessive oxidation (in organic chemistry textbooks, if the ozonation of olefins is to be stopped at the aldehyde stage, a reducing agent must be added after the ozonation reaction. If no reducing agent is added, the reaction will not stop at the aldehyde stage and only carboxylic acids can be generated).

[0072] According to the experimental results, 5.00g of cinnamon oil (cinnamaldehyde content of about 56.46%), 15.00g of anhydrous ethanol, and 0.2g of CaO catalyst were added to the bubbling reactor, and ozone was introduced into the bottom of the mixed liquid of the reactor at a flow rate of 400L / min, and the reaction was carried out at 0°C for 60min to obtain cinnamon oil oxide. After the terpenes were oxidized, only 3.02% remained, and 80.48% of the cinnamaldehyde in the cinnamon oil was retained.

[0073] In addition, due to the similar chemical properties of elements of the same family, Ba and Ca are both alkaline earth metal elements. In the preliminary experiment of this embodiment, the results show that the oxide of Ba can achieve an effect similar to that of the oxide of Ca, so the conclusion of the detailed experimental study of CaO can be analogized to BaO. The catalytic principles of barium hydroxide and calcium hydroxide in the reaction described in the present invention are similar. The reaction process of oxidizing cinnamon oil will generate water. The oxide is used at the beginning. Once the reaction starts, the catalyst of the oxide will become a hydroxide. The catalytic effect of the hydroxide is better than that of the oxide. Therefore, when using oil now, hydroxide is not used directly, and oxides can be used. It can also reduce the adverse effects of water on the reaction and extend the life of the catalyst.

[0074] Example 2

[0075] Weigh 20.00g of calcium nitrate tetrahydrate and dissolve it in deionized water to prepare a solution with a concentration of 0.4mol / L; similarly, weigh 18.97g of ammonium bicarbonate and dissolve it in deionized water to prepare a solution with a concentration of 1.2mol / L. At a water bath temperature of 30°C and a speed of 300r / min, the above prepared ammonium bicarbonate solution is added dropwise to the calcium nitrate solution by a co-current coprecipitation method. The solution changes from clear to turbid. When the pH of the suspension is 7-8, stop adding the ammonium bicarbonate solution. Wait for the precipitate to be aged at a constant temperature of 30°C in the mother liquor for 3h, and then filter it to obtain a precipitate. The obtained precipitate is dried at 90°C for 12h and calcined at 600°C for 2h to obtain a CaO catalyst. In a bubbling reactor, 5.00 g of cinnamon oil (containing about 56.46% cinnamaldehyde), 15.00 g of anhydrous ethanol, and 0.3 g of CaO catalyst were added, and ozone was introduced into the bottom of the mixed solution of the reactor at a flow rate of 400 L / min. The reaction was carried out at 0° C. for 120 min to obtain cinnamon oil oxide. After the terpenes were oxidized, only 2.76% remained, and 39.26% of cinnamaldehyde in the cinnamon oil was retained.

[0076] Example 3

[0077] Weigh 20.00g of calcium nitrate tetrahydrate and dissolve it in deionized water to prepare a solution with a concentration of 0.4mol / L; similarly, weigh 18.97g of ammonium bicarbonate and dissolve it in deionized water to prepare a solution with a concentration of 1.2mol / L. At a water bath temperature of 30°C and a speed of 300r / min, the above prepared ammonium bicarbonate solution is added dropwise to the calcium nitrate solution by a co-current coprecipitation method. The solution changes from clear to turbid. When the pH of the suspension is 7-8, stop adding the ammonium bicarbonate solution. After the precipitate is aged at 30°C in the mother liquor for 3h, it is filtered to obtain a precipitate. The obtained precipitate is dried at 90°C for 12h and calcined at 600°C for 2h to obtain a CaO catalyst. Weigh 5.00g of CaO and 10mL of anhydrous ethanol, stir evenly, add 2mL of ultrapure water, and use a rotary evaporator to remove the solvent to obtain a Ca(OH)2 catalyst. In a bubbling reactor, 5.00 g of cinnamon oil (cinnamaldehyde content of about 56.46%), 15.00 g of anhydrous ethanol, and 0.3 g of Ca(OH)2 catalyst were added respectively, and ozone was introduced into the bottom of the mixed liquid of the reactor at a flow rate of 450 mL / min, and the reaction was carried out at 0°C for 90 minutes to obtain cinnamon oil oxide. After the terpenes were oxidized, only 3.75% remained, and 49.25% of the cinnamaldehyde in the cinnamon oil was retained.

[0078] Example 4

[0079] Weigh 9.76g of barium chloride and dissolve it in deionized water to prepare a solution with a concentration of 0.4mol / L; similarly, weigh 18.97g of ammonium bicarbonate and dissolve it in deionized water to prepare a solution with a concentration of 1.2mol / L. At a water bath temperature of 30℃ and a speed of 300r / min, the above prepared ammonium bicarbonate solution is added dropwise to the barium chloride solution by a co-current coprecipitation method. The solution changes from clear to turbid. When the pH of the suspension is 7-8, stop adding the ammonium bicarbonate solution. Wait for the precipitate to be aged at 30℃ in the mother liquor for 3h, and then filter it to obtain a precipitate. The obtained precipitate is dried at 90℃ for 12h and calcined at 600℃ for 3h to obtain a BaO catalyst. Weigh 5.00g BaO and 10mL of anhydrous ethanol, stir evenly, add 2mL of ultrapure water, and use a rotary evaporator to remove the solvent to obtain a Ba(OH)2 catalyst. In a bubbling reactor, 5.00 g of cinnamon oil (containing about 56.46% cinnamaldehyde), 15.00 g of anhydrous ethanol, and 0.4 g of Ba(OH)2 catalyst were added, and ozone was introduced into the bottom of the mixed solution of the reactor at a flow rate of 400 L / min. The reaction was carried out at 0°C for 120 min to obtain cinnamon oil oxide. After the terpenes were oxidized, only 1.89% of the terpenes remained, and 22.15% of the cinnamaldehyde in the cinnamon oil was retained.

[0080] Example 5

[0081] Weigh 9.76g of barium chloride and dissolve it in deionized water to prepare a solution with a concentration of 0.4mol / L; similarly, weigh 18.97g of ammonium bicarbonate and dissolve it in deionized water to prepare a solution with a concentration of 1.2mol / L. At a water bath temperature of 30°C and a speed of 300r / min, the above prepared ammonium bicarbonate solution is added dropwise to the barium chloride solution by a co-current coprecipitation method. The solution changes from clear to turbid. When the pH of the suspension is 7-8, stop adding the ammonium bicarbonate solution. Wait for the precipitate to be aged at a constant temperature of 30°C in the mother liquor for 3h, and then filter it to obtain a precipitate. The obtained precipitate is dried at 90°C for 12h and calcined at 600°C for 3h to obtain a BaO catalyst. In a bubbling reactor, 5.00 g of cinnamon oil (containing about 56.46% cinnamaldehyde), 15.00 g of anhydrous ethanol, and 0.1 g of BaO catalyst were added, and ozone was introduced into the bottom of the mixed solution of the reactor at a flow rate of 450 mL / min. The reaction was carried out at 0° C. for 30 min to obtain cinnamon oil oxide. After the terpenes were oxidized, only 9.81% of the terpenes remained, and 33.59% of the cinnamaldehyde in the cinnamon oil could be separated later.

Claims

1. A method for removing olefin components in cinnamon oil by ozonation to retain cinnamaldehyde, characterized in that: The steps include: Cinnamon oil and solvent are weighed respectively in a weight ratio of cinnamon oil: solvent = 1:1-3, the cinnamon oil and solvent are evenly mixed, and then placed in a reactor, barium oxide, calcium oxide, barium hydroxide or calcium hydroxide is added as a catalyst according to 1-10% of the mass of the cinnamon oil, ozone is introduced into the reactor, and a heterogeneous catalytic ozone selective oxidation reaction of the cinnamon oil is carried out, and the reaction time is 20-80 minutes.

2. The method for removing olefin components in cinnamon oil by ozonation according to claim 1, characterized in that: The ozone flow rate is 300-600 mL / min.

3. The method for removing olefin components in cinnamon oil by ozonation according to claim 1, characterized in that: The reaction is carried out under normal pressure and at -10 to 25°C.

4. The method for removing olefin components in cinnamon oil by ozonation according to claim 1, characterized in that: The reacted BaO, CaO, Ba(OH)2 and Ca(OH)2 catalysts are washed, dried and reused.

5. The method for removing olefin components in cinnamon oil by ozonation according to claim 1, characterized in that: The solvent is anhydrous ethanol.

6. The method for removing olefin components in cinnamon oil by ozonation according to claim 1, characterized in that: The preparation method of the catalyst is as follows: dissolving nitrate or chloride of barium or calcium metal in deionized water to prepare a solution with a concentration of 0.01-0.4 mol / L; similarly, dissolving ammonium bicarbonate in deionized water to prepare a solution with a concentration of 0.1-2.0 mol / L; dripping the prepared ammonium bicarbonate solution into the metal salt solution by a co-current co-precipitation method at a water bath temperature of 30°C and a rotation speed of 300 r / min, the solution changes from clear to turbid, and when the pH value of the suspension is 7-8, stopping dripping the ammonium bicarbonate solution, and aging the precipitate in the mother liquor at a constant temperature of 30°C for 1-10 hours, and then filtering to obtain a precipitate; drying the obtained precipitate at 80°C for 12-24 hours to obtain Ba(OH)2 and Ca(OH)2 catalysts, and calcining Ba(OH)2 and Ca(OH)2 at a temperature of 300-900°C for 2-3 hours to obtain BaO and CaO catalysts.

7. The method for removing olefin components in cinnamon oil by ozonation according to claim 1, characterized in that: The specific steps are as follows: 1-5g of cinnamon oil and 1-15g of anhydrous ethanol are mixed and placed in a bubbling reactor, the catalyst is added according to 1-10% of the mass of the cinnamon oil, ozone is introduced into the bottom of the mixed liquid of the reactor at a flow rate of 300-600mL / min so that ozone can be fully utilized, and the cinnamon oil is subjected to heterogeneous catalytic ozone oxidation reaction for 20-80min under normal pressure and -10-25°C to obtain the cinnamon oil with olefin components removed and most of cinnamaldehyde retained.

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