A batch rectification system and method for extracting flavorants from chemical by-products

Abstract

This invention relates to a batch distillation system and method for extracting fragrances and flavorings from chemical by-products. The batch distillation feedstock is stored in a condensate tank at the top of the column. During the distillation stage, the light components in the condensate tank are continuously purified, while the heavy components are continuously collected from the bottom of the batch distillation column. The intermediate components containing fragrances and flavorings are continuously purified in this process. By continuously collecting the heavy components, and by continuously feeding the feedstock from the condensate tank rather than having it remain in the bottom of the column during a single feed, repeated heating is avoided. This prevents the charring or decomposition of heavy components caused by high-temperature heating of the bottom material, which can significantly affect the aroma of the fragrance and flavoring products. This method is more conducive to obtaining intermediate components containing fragrances and flavorings with higher purity and acceptable aroma. The fragrance and flavoring products obtained using the distillation system and method of this invention have higher purity, are easier to meet aroma standards, and have a higher pass rate, resulting in higher product efficiency.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, and in particular to an intermittent distillation system and method for extracting fragrances and flavorings from chemical byproducts. Background Technology

[0002] Fragrances and flavorings are widely used as additives in perfume production and other related industries. Besides extracting fragrances and flavorings from natural plants, extracting related products from chemical byproducts is gaining increasing attention and development due to its wide availability and low cost.

[0003] Existing methods for extracting chemical byproducts often employ batch distillation due to the fluctuating composition of the raw materials. However, batch distillation for flavorings and fragrances presents a pressing problem: the raw material is added to the bottom of the distillation column all at once, and the column is continuously heated and concentrated. Different products are obtained at the top of the column depending on the evaporation time. However, because the raw material comes from chemical byproducts, which contain many high-carbon compounds, continuous high-temperature heating causes the heavy components to char or decompose, significantly affecting the aroma of the product.

[0004] Therefore, in response to the problems of existing technologies that continuously heat the materials in the tower at high temperatures, causing the coking or decomposition of heavy components and significantly affecting the aroma of the products, it is currently necessary to develop an efficient separation and purification method to improve the qualification rate of fragrance and flavor products and thus increase product efficiency. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of high energy requirements and the presence of charred flavor in the product from chemical by-products during batch distillation. A new batch distillation system is developed. Using the system and method of this invention, the heavy components are heated and passed through in one pass, reducing the risk of charring or decomposition of the heavy components, thereby reducing energy consumption in the production process and improving product qualification rate and quality.

[0006] like Figure 1 As shown, a first aspect of the present invention is to provide a batch distillation system for extracting fragrances and flavorings from chemical raw materials, comprising:

[0007] The system comprises a chemical raw material source containing fragrances and flavorings, a batch distillation column 5, a top condenser 7, a top condensate storage tank 8, a product buffer tank 13, and a falling film evaporator / reboiler 19; the chemical raw material containing fragrances and flavorings contains light components, intermediate components, and heavy components, the intermediate components containing fragrances and flavorings; the chemical raw material source containing fragrances and flavorings is connected to the inlet of the top condensate storage tank 8 via a chemical by-product feed pipe 1, and the bottom outlet of the top condensate storage tank 8 is connected to the inlet of the batch distillation column 5 via a reflux pipe 3; the top outlet of the batch distillation column 5 is connected to the product buffer tank 5 via a top vapor discharge pipeline 6 and the top condenser 7. The feed inlet of the top condensate storage tank 8 is connected to the bottom of the batch distillation column 5; the bottom liquid outlet of the batch distillation column 5 is connected to the top feed inlet of the falling film evaporator-reboiler 19 via the bottom liquid pipeline 16, so as to collect the heavy components in the batch distillation column 5 from the bottom outlet of the falling film evaporator-reboiler 19; the batch distillation column 5 is provided with a side outlet, which is connected to the feed inlet of the product buffer tank 13 via the intermediate product collection pipeline 12; the bottom outlet of the product buffer tank 13 is selectively connected to the feed inlet of the top condensate storage tank 8 via the unqualified product circulation pipeline 2 or connected to external equipment via the product pipeline 15.

[0008] Because chemical raw materials containing fragrances and flavorings are generally chemical by-products with complex compositions, and the target product, fragrances and flavorings, are not the lightest or heaviest components, but generally intermediate components, and considering the high temperature of the tower bottom and its impact on the aroma of the fragrances, a side-stream sampling method near the middle of the tower is adopted.

[0009] The heavy components of this invention are extracted in a single pass through a falling film evaporator. In the falling film evaporator-reboiler, the material flows in a thin film state along the inner wall of the falling film tube from top to bottom while evaporating due to its own weight and the action of its secondary steam flow, while the steam outside the falling film tube is condensed. This flow method results in a very short residence time of the material in the heating section, thus making it less likely to cause material deterioration, and enabling the heavy components to be extracted in one pass without returning to the batch distillation column 5.

[0010] The entire distillation process of this invention is similar to the reverse process of traditional batch distillation, that is, the light component product at the top of the column is continuously concentrated, and the heavy component is continuously collected from the bottom of the column. This fundamentally avoids the problem of repeated high-temperature heating of the raw material in the bottom of the column, which leads to the coking and decomposition of the heavy component and affects the aroma. It also realizes the collection of heavy component and the enrichment and purification of light component, which contains higher purity of fragrance and flavor intermediate components, and is more conducive to obtaining a product with qualified aroma.

[0011] Furthermore, the material is heated by a falling film evaporator, causing partial vaporization. The vaporized gas is returned to the batch distillation column, while the liquid phase containing heavy components is collected in a single pass through the falling film evaporator, which can shorten the heating time of the material in the column bottom.

[0012] In this invention, the top condensate storage tank 8 is equivalent to combining the reflux storage tank and the top distillate storage tank into one. During the distillation stage, all the gas phase coming out of the batch distillation column 5 is condensed into the condensate storage tank 8. However, not all the condensed liquid phase returns to the top condensate storage tank 8. Instead, a portion remains in the top condensate storage tank 8, and a portion returns to the batch distillation column 5.

[0013] The present invention is applicable to a wide range of chemical raw materials containing fragrances and flavorings. Preferably, the chemical raw material source containing fragrances and flavorings in the styrene tar is a styrene tar source, containing at least one of aromatic alcohols, alkylphenols, and styrene dimers.

[0014] Preferably, the bottom outlet of the condensate storage tank 8 at the top of the tower can also be connected to external equipment via a distillate pipe 11; preferably, a flow meter is installed on the distillate pipe 11.

[0015] Preferably, a flow meter is installed on the return pipe 3.

[0016] Preferably, the bottom of the falling film evaporator reboiler 19 is provided with a steam outlet, which is connected to the feed inlet located at the bottom of the batch distillation column 5 through the reboiler reflux line 4. This allows a portion of the components discharged with the heavy components to be reused as raw material in the batch distillation column 5, which is more conducive to improving the product yield.

[0017] Preferably, the device through which the bottom liquid passes is a falling film evaporator-reboiler 9, specifically a single-effect falling film evaporator. The feed to the falling film evaporator is controlled by a flow regulating valve on the bottom pump 17. Heavy components in the bottom liquid pass through the falling film evaporator-reboiler 19 in a single pass. The vapor in the falling film evaporator-reboiler 19 returns to the batch distillation column 5 via the reboiler reflux line 4. The liquid phase in the falling film evaporator-reboiler 9 is collected via the bottom liquid collection line 20. This shortens the heating time of the bottom material and further avoids the coking and decomposition of heavy components.

[0018] Preferably, a bottom pump 17 is installed on the pipeline between the bottom outlet of the batch distillation column 5 and the inlet of the falling film evaporator-reboiler 19.

[0019] Preferably, the falling film evaporator-reboiler 19 has a heat source inlet at the upper part of its shell and a heat source outlet at the lower part. The heat source inlet is connected to a steam heat source via a steam pipeline 21; the heat source outlet is connected to downstream equipment via a steam condensate pipeline 22. The heat source is generally steam, usually sourced from an external steam source, such as a steam boiler or steam generator. The steam provided by these steam sources is transported to the shell of the falling film evaporator-reboiler through pipelines for heating and condensation processes.

[0020] When the chemical raw material source containing fragrance and flavor is styrene tar and contains at least one of aromatic alcohols, alkylphenols, and styrene dimers, preferably, the batch distillation column 5 has 60-100 theoretical plates; and / or, preferably, the side stream outlet of the batch distillation column 5 is located between the 20th and 40th plates from the top. This results in fragrance and flavor products with higher purity and easier-to-qualify aroma.

[0021] Preferably, a product delivery pump 14 is installed on the pipeline of the bottom outlet of the product buffer tank 13.

[0022] In this invention, the pumps, flow meters, etc. installed on the pipelines can help improve the conveying efficiency or achieve more precise control over product distribution.

[0023] Preferably, the top of the condensate storage tank 8 is provided with a pressure regulating port, which is connected to an external pressure regulating device via a vacuum line 9; the top of the product buffer tank 13 is provided with a vapor phase balance port, which is connected to the vacuum line 9 via a vapor phase balance line 10. Negative pressure distillation is preferably employed, so that the batch distillation column 5 operates under negative pressure, and the vapor phase balance line is used to create negative pressure in the product buffer tank 13, facilitating the outflow of side-collected materials.

[0024] According to the present invention, the batch distillation column 5 is provided with a collection tank for collecting the intermediate liquid phase product flowing down from the top of the column into the tank, and the liquid phase product in the collection tank is then collected from the side outlet of the batch distillation column 5.

[0025] A second aspect of the present invention is to provide a method for extracting fragrances and flavorings from chemical raw materials using the batch distillation system described in the first aspect, comprising:

[0026] S1. Chemical raw materials containing fragrances and flavorings are fed into the top condensate storage tank 8 in one go, and then transported to the batch distillation column 5 for distillation. The top vapor phase of the batch distillation column 5 is cooled by the top condenser 7 and enters the top condensate storage tank 8. The liquid in the top condensate storage tank 8 is recycled back into the batch distillation column 5. The light components flowing out of the batch distillation column 5 are purified and enriched in the top condensate storage tank 8.

[0027] S2. When the bottom temperature of the batch distillation column 5 rises to a first set value, where the first set value is the bubble point temperature of the heavy components, the bottom liquid of the batch distillation column 5 begins to continuously pass through the falling film evaporator-reboiler 19 to collect the heavy components.

[0028] S3. During the process of extracting heavy components, the temperature of the bottom of the batch distillation column 5 continuously decreases. When it reaches the second set value, which is the bubble point temperature of the intermediate component, the bottom liquid containing flavorings and fragrances is continuously extracted through the side outlet of the batch distillation column 5 and enters the product buffer tank 13.

[0029] During processes S1, S2, and S3, the top condensate storage tank 8 continuously supplies feed to the batch distillation column 5 to maintain the bottom liquid in the batch distillation column 5 at the target liquid level.

[0030] S4. Test the liquid collected in the product buffer tank 13. If it meets the requirements for fragrance and flavor, it is collected; otherwise, it is returned to the condensate storage tank 8 at the top of the tower.

[0031] By taking samples from the product buffer tank 13, the quality of the fragrance and flavor is tested, including but not limited to purity testing and aroma testing. If the fragrance and flavor sample is unqualified, the material taken from the side stream is returned to the condensate storage tank 8 at the top of the tower.

[0032] According to the present invention, the product containing fragrance and flavoring obtained from the one-time feeding and distillation of chemical raw materials containing fragrance and flavoring (i.e., product liquid) is entirely stored in the product buffer tank 13. The liquid collected in the product buffer tank 13 is sampled and tested. After the fragrance and flavoring sample passes the inspection, the liquid in the product buffer tank 13 is directly withdrawn. Simultaneously, the residual liquid phase in the overhead condensate storage tank 8 is also withdrawn at once through the distillate pipe 11, and the bottom liquid is also completely withdrawn at once. That is, the extraction process of each batch of raw materials in the present invention involves a single feeding into the overhead condensate storage tank 8, continuous feeding into the overhead condensate storage tank 8 for distillation, continuous collection of heavy components from the bottom liquid during distillation, continuous collection of product liquid, and collection of all product liquid obtained in this batch in the product buffer tank 13. After the fragrance and flavoring sample in the product buffer tank 13 passes the inspection, the product liquid in the product buffer tank 13 is withdrawn at once, while simultaneously emptying the residual liquid phase in the overhead condensate storage tank 8 and the bottom liquid of the batch distillation column 5.

[0033] As mentioned above, the chemical raw materials containing fragrances and flavorings in this invention have a wide range of applications. For example, this invention is particularly suitable for extracting fragrances and flavorings from styrene tar.

[0034] The PO / SM unit primarily produces propylene oxide and styrene, with acetophenone as a main byproduct. It also produces high-boiling-point components such as β-phenylethanol, phenylpropanol, and 2-ethylphenol. Without separation, these high-boiling byproducts accumulate to a certain concentration, affecting the activity of dehydration or hydrogenation catalysts, destabilizing the reaction system, and reducing styrene yield. These high-boiling byproducts eventually accumulate in styrene tar.

[0035] Styrene tar has a complex composition, mainly containing aromatic alcohols, alkylphenols, styrene dimers, etc. The main components are: 2,3-diphenyl-2-butene (20%-30%), 1-phenoxy-2-propanol (5%-15%), β-phenylethanol (30%-40%), phenols (5%-10%), and others, in terms of mass percentage.

[0036] This invention is particularly applicable to the separation and purification of β-phenylethanol flavoring products from styrene tar, a byproduct of styrene production.

[0037] Preferably, the chemical raw material containing fragrance and flavoring contains 2,3-diphenyl-2-butene, 1-phenoxy-2-propanol, β-phenylethanol, and alkylphenol; more preferably,

[0038] The chemical raw materials containing fragrances and flavorings contain 20%-30% 2,3-diphenyl-2-butene, 5%-15% 1-phenoxy-2-propanol, 30%-40% β-phenylethanol, and 5%-10% alkylphenols, by mass percentage.

[0039] For the separation and purification of β-phenylethanol flavoring and fragrance products from styrene tar by-product:

[0040] Preferably, the flavoring includes β-phenylethanol.

[0041] Preferably, the light components purified and enriched in the overhead condensate storage tank 8 in step S1 include alkylphenols, including but not limited to 4-ethylphenol, 3-ethylphenol, and 2-ethylphenol; in addition to alkylphenols, the light components also include but are not limited to at least one of di(2-hydroxypropyl) ether, 1-phenylethanol, pseudotrimethylbenzene, p-xylene, and 4-methyl-2-phenyl-1,3-dioxolane.

[0042] Preferably, the recombinant fraction collected in step S2 includes 2,3-diphenyl-2-butene and 1-phenoxy-2-propanol. The recombinant fraction collected in step S2 also includes, but is not limited to, at least one of 5,6,7,8-cyclooctene, benzenemethylacetophenone, 1-phenyl-naphthalene, 9,9-dimethylfluorene, 1,3-diphenyl-1-butene, 1,2-diphenylcyclopropane, 1,3-diphenylpropane, 1,3-phenylbutane, 2-methyl-1,1-diphenylpropene, 2-phenylethyl hexanoate, 4-methyldiphenylmethane, 2-phenylpropyl isobutyrate, dimethylphenylethanol, diphenylmethane, 3,3-dimethyl-1-indanol, 4-phenyl-1-cyclohexene, phenylbutanone, phenylpropenone, 2-phenyl-1-propanol, and 1-phenyl-2-propanol.

[0043] Preferably, the material flowing out of the steam outlet of the falling film evaporator-reboiler 19 is returned to the intermittent distillation column 5.

[0044] Preferably, total reflux is performed at the beginning of the distillation stage. After the heavy components are collected, reflux is performed again at a reflux ratio of 20-60. Under this preferred reflux ratio condition, the β-phenylethanol fragrance product has higher purity.

[0045] Preferably, the operating conditions of the batch distillation column 5 include:

[0046] The operating pressure is 5 kPaA-60 kPaA, preferably 5 kPaA-50 kPaA. Under the preferred distillation operating pressure conditions, the purity of the β-phenylethanol fragrance product is higher, and the yield is also higher.

[0047] Preferably, the first set value is 120-150℃.

[0048] Preferably, the second setting value is 100-120℃.

[0049] Preferably, the operating temperature of the top condenser 7 is 80-100℃.

[0050] Preferably, the operating temperature of the condensate storage tank 8 at the top of the tower is 50-80℃.

[0051] Preferably, the operating temperature range of the falling film evaporator reboiler 19 is 80-150℃.

[0052] Preferably, the target liquid level in the bottom of the batch distillation column 5 is located at 1 / 3 to 1 / 2 of the distance between the last tray and the bottom outlet of the batch distillation column 5, measured along the direction from the bottom outlet to the tray.

[0053] Preferably, the purity of β-phenylethanol in the liquid in the product buffer tank 13 is above 99%, and the aroma is qualified, thus meeting the qualification requirements.

[0054] The advantages of this invention are:

[0055] The distillation system and method of this invention differ from conventional distillation columns for extracting fragrances and flavorings. In this invention, the feed material for batch distillation is stored in a condensate tank at the top of the column. During the distillation stage, the light components in the condensate tank are continuously purified, while the heavy components are continuously collected from the bottom of the batch distillation column. The intermediate components containing fragrances and flavorings are continuously purified in this process. By continuously collecting the heavy components, and because the feed liquid is stored in the condensate tank at the top of the column before continuous feeding, rather than remaining in the bottom of the column after a single feed, repeated heating is avoided, thus preventing high-temperature heating of the bottom material. The coking or decomposition of heavy components in raw materials can significantly affect the aroma of fragrance and flavor products. This invention addresses this issue by pre-collecting the heavy components before they coke or decompose, and purifying and enriching the light components in the overhead condensate storage tank. This separates the light, intermediate, and heavy components from the chemical raw materials containing fragrances and flavors into different directions, making it easier to obtain intermediate components with higher purity and acceptable aroma. The fragrance and flavor products obtained using the distillation system and method of this invention have higher purity, are easier to meet aroma standards, and have a higher pass rate, resulting in higher product efficiency.

[0056] The advantages of the present invention will be further explained below with reference to specific embodiments. Attached Figure Description

[0057] Figure 1 This is a process flow diagram of an embodiment of the present invention;

[0058] Figure 1 In the diagram: 1 is the feed pipeline for chemical by-products, 2 is the circulation pipeline for non-conforming products, 3 is the reflux pipeline, 4 is the reboiler reflux pipeline, 5 is the batch distillation column, 6 is the top vapor discharge pipeline, 7 is the top condenser, 8 is the top condensate storage tank, 9 is the vacuum pipeline, 10 is the vapor balance pipeline, 11 is the distillate pipeline, 12 is the intermediate product pipeline, 13 is the product buffer tank, 14 is the product transfer pump, 15 is the product pipeline, 16 is the bottom liquid pipeline, 17 is the bottom pump, 18 is the reboiler feed pipeline, 19 is the falling film evaporator reboiler, 20 is the bottom liquid discharge pipeline, 21 is the steam pipeline, 22 is the steam condensate pipeline, and LC is the liquid level sensor. Detailed Implementation

[0059] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0060] In the following embodiments, such as Figure 1 As shown, a batch distillation system for extracting fragrances and flavorings from chemical raw materials includes:

[0061] The distillation column comprises a chemical raw material source containing fragrances and flavorings, a batch distillation column 5, a top condenser 7, a top condensate storage tank 8, a product buffer tank 13, and a falling film evaporator-reboiler 19. The chemical raw material source containing fragrances and flavorings is connected to the inlet of the top condensate storage tank 8 via a chemical by-product feed pipe 1. The bottom outlet of the top condensate storage tank 8 is connected to the inlet of the batch distillation column 5 via a reflux pipe 3. The top outlet of the batch distillation column 5 is connected to the inlet of the top condensate storage tank 8 via a top vapor discharge pipeline 6 and the top condenser 7. The bottom outlet of the distillation column 5 is connected to the top inlet of the falling film evaporator-reboiler 19 via the bottom outlet of the falling film evaporator-reboiler 19, so as to collect the heavy components in the batch distillation column 5 from the bottom outlet of the falling film evaporator-reboiler 19; the batch distillation column 5 is provided with a side outlet, which is connected to the inlet of the product buffer tank 13 via the intermediate product outlet pipeline 12; the bottom outlet of the product buffer tank 13 is selectively connected to the inlet of the top condensate storage tank 8 via the unqualified product circulation pipeline 2 or connected to external equipment via the product pipeline 15. The bottom outlet of the condensate storage tank 8 at the top of the column can optionally be connected to external equipment via a distillate pipeline 11; the bottom of the falling film evaporator reboiler 19 is provided with a steam outlet, which is connected to the feed inlet located at the bottom of the batch distillation column 5 via a reboiler reflux pipeline 4; the bottom of the falling film evaporator reboiler 19 is provided with a steam outlet, which is connected to the feed inlet located at the bottom of the batch distillation column 5 via a reboiler reflux pipeline 4; a flow meter is installed on the distillate pipeline 11, and a flow meter is installed on the reflux pipeline 3; a bottom pump 17 is installed on the pipeline between the bottom bottom outlet of the batch distillation column 5 and the feed inlet of the falling film evaporator reboiler 19; the falling film evaporator reboiler 19 is connected to the distillate pipeline 11, which is connected to the feed inlet of the batch distillation column 5 ... The membrane evaporator reboiler 19 has a heat source inlet at the top and a heat source outlet at the bottom. The heat source inlet is connected to a steam heat source via a steam pipeline 21. The heat source outlet is connected to downstream equipment via a steam condensate pipeline 22. A product transfer pump 14 is installed on the pipeline at the bottom outlet of the product buffer tank 13. A pressure regulating port is installed at the top of the column top condensate storage tank 8, and the pressure regulating port of the column top condensate storage tank 8 is connected to an external pressure regulating device via a vacuum pipeline 9. A vapor phase balance port is installed at the top of the product buffer tank 13, and the vapor phase balance port of the product buffer tank 13 is connected to the vacuum pipeline 9 via a vapor phase balance pipeline 10. An LC level sensor is installed at the bottom of the batch distillation column 5.

[0062] Unless otherwise specified, the equipment used in the following embodiments are all commercially available devices in the art.

[0063] In the following examples, the chemical raw material containing fragrance and flavoring is styrene tar. The content of each component in the styrene tar is shown in Table 1, with the total mass of styrene tar being 100%.

[0064] Table 1

[0065] Serial Number name Percentage of mass 1 5,6,7,8-Cyclooctene 0.39％ 2 Benzenemethylacetophenone 0.39％ 3 1-Phenylanthide 0.25％ 4 9,9-Dimethylfluorene 0.16％ 5 1,3-Diphenyl-1-butene 5.65％ 6 2,3-Diphenyl-2-butene 24.48％ 7 1,2-Diphenylcyclopropane 0.28％ 8 1,3-Diphenylpropane 0.44％ 9 1,3-Phenylacetane 2.13％ 10 2-Methyl-1,1-diphenylpropene 0.37％ 11 2-Phenylethyl hexanoate 0.33％ 12 4-Methyldiphenylmethane 0.28％ 13 2-Phenylacetyl isobutyrate 0.21％ 14 Dimethylphenylethanol 0.10％ 15 diphenylmethane 0.10％ 16 3,3-Dimethyl-1-indanol 1.09％ 17 1-Phenoxy-2-propanol 8.71％ 18 4-Phenyl-1-cyclohexene 0.21％ 19 Phenylbutanone 0.29％ 20 Phenylacetone 0.09％ 21 2-Phenyl-1-propanol 4.85％ 22 1-Phenyl-2-propanol 2.31％ 23 β-Phenylenol 39.89％ 24 4-Ethylphenol 1.03％ 25 3-Ethylphenol 0.53％ 26 Di(2-hydroxypropyl) ether 0.17％ 27 2-Ethylphenol 4.40％ 28 1-Phenylephethanol 0.08％ 29 Trimethylbenzene 0.10％ 30 p-xylene 0.44％ 31 4-Methyl-2-phenyl-1,3-dioxolane 0.25％

[0066] The purity of β-phenylethanol in β-phenylethanol fragrance and flavor products was determined by chromatographic analysis.

[0067] The method for testing whether the fragrance of β-phenylethanol fragrance products is up to standard is to have a fragrance taster issue a fragrance taste report, which mainly analyzes whether there are any off-flavors.

[0068] In the following examples, the yield of β-phenylethanol fragrance products is calculated as follows:

[0069] Yield = (mass of β-phenylethanol in the final product) / (mass of β-phenylethanol in the feedstock) * 100%

[0070] Example 1

[0071] Adopting such Figure 1 The batch distillation system shown represents a method for extracting fragrances and flavorings from chemical raw materials, comprising:

[0072] S1. Chemical raw materials containing fragrances and flavorings are stored in the overhead condensate storage tank 8 and then continuously fed into the batch distillation column 5 for distillation. The distillation operation pressure is 15 kPaA. The vapor phase at the top of the batch distillation column 5 is cooled by the overhead condenser 7 and enters the overhead condensate storage tank 8. The liquid in the overhead condensate storage tank 8 is recycled back into the batch distillation column 5. The light components flowing out of the batch distillation column 5 are purified and enriched in the overhead condensate storage tank 8. During this process, no material is collected from the bottom or top of the batch distillation column 5.

[0073] At the beginning of the distillation process, total reflux is performed first. Once the heavy components are started to be collected, reflux is performed at a reflux ratio of 27.

[0074] S2. When the bottom temperature of the batch distillation column 5 rises to the first set value of 139°C, the bottom liquid of the batch distillation column 5 begins to continuously pass through the falling film evaporator-reboiler 19 to collect heavy components (including tar heavy components, 2,3-diphenyl-2-butene, 1-phenoxy-2-propanol, etc.); the material flowing out of the steam outlet of the falling film evaporator-reboiler 19 is returned to the batch distillation column 5;

[0075] S3. During the process of extracting heavy components, the temperature of the bottom of the batch distillation column 5 continuously decreases. When it reaches the second set value of 114°C, the bottom liquid containing β-phenylethanol is continuously extracted through the side outlet of the batch distillation column 5 and enters the product buffer tank 13.

[0076] During processes S1, S2 and S3, the top condensate storage tank 8 continuously supplies feed to the batch distillation column 5, and the feed level in the batch distillation column 5 is controlled at 1 / 2 between the last tray of the distillation column and the bottom outlet.

[0077] S4. Collect the product liquid obtained from this batch of raw materials through the product buffer tank 13, and sample and test the product liquid in the product buffer tank 13. If it meets the requirements for qualified fragrance and flavor, it is extracted.

[0078] The operating temperature of the top condenser 7 is 92℃;

[0079] The operating temperature of the condensate storage tank 8 at the top of the tower is 60°C.

[0080] The operating temperature range of the falling film evaporator-reboiler 19 is 145°C;

[0081] The theoretical number of plates in batch distillation column 5 is 81;

[0082] After the product discharge is completed, the light components in the top condensate storage tank 8 are all extracted at once through the distillate pipeline 11; the bottom liquid is also extracted at once.

[0083] The purity of β-phenylethanol in the product buffer tank 13 was tested, and the liquid was also sampled and its aroma was assessed. The yield of the extracted β-phenylethanol-containing fragrance was calculated. Details of the qualified products are shown in Table 2.

[0084] Example 2

[0085] The method of Example 1 was used to extract fragrances and flavorings from chemical raw materials, except that the distillation operation pressure was 40 kPaA.

[0086] The purity of β-phenylethanol in the product buffer tank 13 was tested, and the liquid was also sampled and its aroma was assessed. The yield of the extracted β-phenylethanol-containing fragrance was calculated. Details of the qualified products are shown in Table 2.

[0087] Example 3

[0088] The method of Example 1 was used to extract fragrances and flavorings from chemical raw materials, except that the distillation reflux ratio was 30.

[0089] The purity of β-phenylethanol in the product buffer tank 13 was tested, and the liquid was also sampled and its aroma was assessed. The yield of the extracted β-phenylethanol-containing fragrance was calculated. Details of the qualified products are shown in Table 2.

[0090] Example 4

[0091] The method of Example 1 was used to extract fragrances and flavorings from chemical raw materials, except that the distillation operation pressure was 60 kPaA.

[0092] The purity of β-phenylethanol in the product buffer tank 13 was tested, and the liquid was also sampled and its aroma was assessed. The yield of the extracted β-phenylethanol-containing fragrance was calculated. Details of the qualified products are shown in Table 2.

[0093] Comparative Example 1

[0094] The method of distillation system in Example 1 is used to extract fragrances from chemical raw materials. The difference is that the entire feed is directly added to the bottom of the distillation column. As a result, a large amount of material in the bottom of the column remains at a high temperature, causing some of the heavy components at the bottom of the batch distillation column 5 to coke, making it difficult to obtain a fragrance product containing β-phenylethanol that meets the required fragrance quality.

[0095] Comparative Example 2

[0096] The method of distillation system in Example 1 is used to extract fragrances from chemical raw materials. However, instead of using a side stream to extract the product, the product is discharged directly from the top of the column, resulting in the product purity not meeting the requirements.

[0097] Comparative Example 3

[0098] The method of distillation system in Example 1 is used to extract fragrances from chemical raw materials. The difference is that a forced reflux reboiler is used instead of a falling film evaporator reboiler. In this way, the material in the bottom of the column is repeatedly reheated in the heat exchanger, which causes the heavy components at the bottom of the batch distillation column 5 to coke, making it difficult to obtain a fragrance product containing β-phenylethanol that meets the required fragrance quality.

[0099] Table 2

[0100]

[0101]

[0102] As shown in Table 2, the β-phenylethanol fragrance products obtained in Comparative Examples 1-3 failed to meet aroma quality standards. Compared with the comparative examples, the extraction method of fragrances using the batch distillation system of this invention achieves superior purity and aroma quality for the target product, and the high recovery rate also ensures the profitability of the enterprise. A comparison between Example 1 and Example 4 shows that under the preferred distillation pressure conditions of this invention, the β-phenylethanol fragrance product exhibits higher purity.

[0103] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

[0104] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0105] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0106] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values; such ranges or values ​​should be understood to include values ​​close to them. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In principle, various technical solutions can be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0107] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

[0108] Furthermore, any implementation described herein can be freely combined with one or more other implementations described herein, and the resulting technical solutions or technical ideas shall be regarded as part of the original disclosure or original record of the present invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider the combination to be obviously unreasonable.

Claims

1. A batch distillation system for extracting fragrances and flavorings from chemical raw materials, comprising: Chemical raw material source containing fragrance and flavor, batch distillation column (5), column top condenser (7), column top condensate storage tank (8), product buffer tank (13) and falling film evaporator reboiler (19); The chemical raw material containing fragrance and flavoring contains light components, intermediate components, and heavy components, wherein the intermediate components contain fragrance and flavoring. The chemical raw material source containing fragrance and flavoring is connected to the inlet of the top condensate storage tank (8) through the chemical by-product feed pipeline (1). The bottom outlet of the top condensate storage tank (8) is connected to the inlet of the batch distillation column (5) through the reflux pipeline (3). The top outlet of the batch distillation column (5) is connected to the inlet of the top condensate storage tank (8) through the top vapor discharge pipeline (6) and the top condenser (7). The bottom outlet of the batch distillation column (5) is connected to the top inlet of the falling film evaporator-reboiler (19) via the bottom liquid pipeline (16) so as to collect the heavy components in the batch distillation column (5) from the bottom outlet of the falling film evaporator-reboiler (19). The intermittent distillation column (5) is provided with a side outlet. The side outlet is connected to the inlet of the product buffer tank (13) through the intermediate product collection pipeline (12). The bottom outlet of the product buffer tank (13) is selectively connected to the inlet of the top condensate storage tank (8) through the unqualified product circulation pipeline (2) or connected to external equipment through the product pipeline (15).

2. The batch distillation system according to claim 1, characterized in that: The chemical raw material source containing fragrance and flavoring is a styrene tar source, wherein the styrene tar contains at least one of aromatic alcohols, alkylphenols, and styrene dimers; and / or, The bottom outlet of the condensate storage tank (8) at the top of the tower can optionally be connected to external equipment via a distillate pipe (11); preferably, a flow meter is installed on the distillate pipe (11); and / or, A flow meter is installed on the return pipe (3).

3. The batch distillation system according to claim 1, characterized in that: The bottom of the falling film evaporator reboiler (19) is provided with a steam outlet, which is connected to the feed inlet located at the bottom of the batch distillation column (5) via the reboiler reflux line (4); and / or, A bottom pump (17) is installed on the pipeline between the bottom outlet of the batch distillation column (5) and the inlet of the falling film evaporator-reboiler (19); and / or, The falling film evaporator reboiler (19) has a heat source inlet at the top and a heat source outlet at the bottom. The heat source inlet is connected to a steam heat source via a steam pipeline (21), and the heat source outlet is connected to downstream equipment via a steam condensate pipeline (22).

4. The batch distillation system according to claim 1, characterized in that: The batch distillation column (5) has 60-100 theoretical plates; and / or, The side feed outlet of the batch distillation column (5) is located between the 20th and 40th trays from the top; and / or, A product delivery pump (14) is installed on the pipeline of the bottom outlet of the product buffer tank (13).

5. The batch distillation system according to any one of claims 1-4, characterized in that: The top of the condensate storage tank (8) is provided with a pressure regulating port, and the pressure regulating port of the condensate storage tank (8) is connected to an external pressure regulating device through a vacuum line (9); the top of the product buffer tank (13) is provided with a gas phase balance port, and the gas phase balance port of the product buffer tank (13) is connected to the vacuum line (9) through a gas phase balance line (10).

6. A method for extracting fragrances and flavorings from chemical raw materials using the batch distillation system according to any one of claims 1-5, comprising: S1. Chemical raw materials containing fragrances and flavorings are fed into the top condensate storage tank (8) of the column in one go, and then transported to the batch distillation column (5) for distillation. The top vapor phase of the batch distillation column (5) is cooled by the top condenser (7) and enters the top condensate storage tank (8). The liquid in the top condensate storage tank (8) is recycled back into the batch distillation column (5). The light components flowing out of the batch distillation column (5) are purified and enriched in the top condensate storage tank (8). S2. When the bottom temperature of the batch distillation column (5) rises to a first set value, the first set value is the bubble point temperature of the heavy components, and the bottom liquid of the batch distillation column (5) begins to continuously pass through the falling film evaporator reboiler (19) to collect the heavy components. S3. During the process of extracting heavy components, the temperature of the bottom of the intermittent distillation column (5) continuously decreases. When the second set value is reached, the second set value is the bubble point temperature of the intermediate component. The bottom liquid containing fragrance and flavoring is continuously extracted through the side outlet of the intermittent distillation column (5) and enters the product buffer tank (13). During processes S1, S2 and S3, the top condensate storage tank (8) continuously feeds the batch distillation column (5) to maintain the bottom liquid in the batch distillation column (5) at the target level; S4. Test the liquid collected in the product buffer tank (13). If it meets the requirements for fragrance and flavor, it is collected. Otherwise, it is returned to the condensate storage tank (8) at the top of the tower.

7. The method according to claim 6, characterized in that: The chemical raw materials containing fragrances and flavorings contain 2,3-diphenyl-2-butene, 1-phenoxy-2-propanol, β-phenylethanol, and alkylphenols; preferably, The chemical raw materials containing fragrances and flavorings contain 20%-30% 2,3-diphenyl-2-butene, 5%-15% 1-phenoxy-2-propanol, 30%-40% β-phenylethanol, and 5%-10% alkylphenols, by mass percentage.

8. The method according to claim 7, characterized in that: The fragrance includes β-phenylethanol; and / or, The light components purified and enriched in the overhead condensate storage tank (8) of step S1 include alkylphenols; and / or, The recombinant material collected in step S2 comprises 2,3-diphenyl-2-butene, 1-phenoxy-2-propanol; and / or, The material flowing out of the steam outlet of the falling film evaporator (19) is returned to the intermittent distillation column (5).

9. The method according to claim 7, characterized in that: The conditions for distillation in S1 include: At the beginning of the distillation process, total reflux is performed first. Once heavy components are collected, reflux is then performed at a ratio of 20-60. And / or, the operating conditions of the batch distillation column (5) include: The operating pressure is 5 kPaA-60 kPaA, preferably 5 kPaA-50 kPaA; and / or, The first setting value is 120-150℃; And / or, the second setting value is 100-120℃; and / or, The operating temperature of the top condenser (7) is 80-100℃; and / or, The operating temperature of the condensate storage tank (8) at the top of the tower is 50-80℃; and / or, The operating temperature range of the falling film evaporator reboiler (19) is 80-150℃; and / or, The target liquid level in the bottom of the batch distillation column (5) is located at 1 / 3 to 1 / 2 of the distance between the last tray and the bottom outlet of the batch distillation column (5), measured along the direction from the bottom outlet to the tray.

10. The method according to any one of claims 7-9, characterized in that: If the purity of β-phenylethanol in the liquid in the product buffer tank (13) is above 99% and the aroma is qualified, then the product meets the qualification requirements.

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