A recovery method of beta-phenylethanol

Abstract

The present application relates to a kind of process for recovering beta-phenylethanol from propylene oxide / styrene plant waste liquid;PO / SM device waste liquid contains 40-80% beta-phenylethanol, the byproduct is subjected to heavy removal, washing, phenol removal, rectification, stripping, i.e. high-purity beta-phenylethanol can be obtained, product purity >99.95%, total impurities of organic matter <200ppm, single impurity <50ppm, key impurity ethyl phenol content is not detected;Product smell is soft, can be used in downstream flavor field;Purification process flow is simple, conducive to the value of industrial chain.

Description

TECHNICAL FIELD

[0001] The present application relates to a process for recovering beta-phenylethanol from PO / SM device waste liquid, belonging to the technical field of recovering high value-added fine chemicals from organic waste liquid. BACKGROUND

[0002] Beta-phenylethanol, also known as 2-phenylethanol and phenylethanol, is a colorless liquid at room temperature, with a delicate, delicate and lasting rose fragrance. It was first discovered as a characteristic fragrance compound in plant flowers, and naturally exists in aromatic oils such as orange flower oil, rose oil and leaf oil.

[0003] A large amount of waste liquid containing beta-phenylethanol is produced in the process of producing propylene oxide and co-producing styrene by co-oxidation technology. The main impurities are acetophenone, phenylacetaldehyde, alpha-phenylethanol, ethyl phenol, and tar, polymer, etc. There are many isomers in the waste liquid, such as alpha-phenylethanol, ethyl phenol and beta-phenylethanol, especially ethyl phenol and beta-phenylethanol, which have close boiling points, making it difficult to purify and recover beta-phenylethanol. Therefore, the waste liquid is often used as fuel liquid for boiler incineration. However, waste liquid incineration generally produces secondary pollution: flue gas from tail gas and dust removal wastewater from scrubbing flue gas; on the other hand, it has high investment and low benefit, which is also a waste of high value-added fine chemicals contained therein.

[0004] Therefore, the development of waste liquid purification technology can realize the recycling of beta-phenylethanol resources, increase the benefit, and at the same time reduce the pollution of the environment. SUMMARY

[0005] The present application provides a process for recovering beta-phenylethanol from PO / SM device waste liquid to solve the problems in the prior art.

[0006] To achieve the above purpose, the following technical solutions are adopted in the present application:

[0007] A process for recovering beta-phenylethanol from PO / SM device production waste liquid, comprising the following steps:

[0008] (1) The PO / SM device production waste liquid is subjected to heavy component removal to obtain a heavy component removal component from which tar and polymer are removed

[0009] (2) The heavy component removal component obtained in step (1) is subjected to alkali washing to obtain an organic phase (mainly beta-phenylethanol, alpha-phenylethanol, and a small amount of inorganic salt brought in by alkali washing) from which most of the ethyl phenol is removed

[0010] (3) The phenol removal organic phase obtained in step (2) is subjected to water washing to obtain an organic phase (mainly containing alpha-phenylethanol and beta-phenylethanol) with metal ions <10ppm

[0011] (4) The organic phase with metal ion <10 ppm obtained in step (3) is subjected to resin phenol removal to obtain an organic phase with phenol content <10 ppm (mainly containing α-phenylethanol, β-phenylethanol)

[0012] (5) The organic phase with phenol content <10 ppm obtained in step (4) is subjected to rectification to obtain a β-phenylethanol product.

[0013] Further, the β-phenylethanol content in the waste liquid produced by the PO / SM device is 40-80 wt%, and other impurities mainly include α-phenylethanol, ethyl phenol, tar, and polymers (mainly polystyrene).

[0014] In the present application, the heavy component removal is performed using a vacuum scraper thin film evaporator at a pressure of 1-10 KPaA and a temperature of 100-150°C. Preferably, the heavy component removal product mainly contains β-phenylethanol, α-phenylethanol, ethyl phenol, tar, and no polymer is detected.

[0015] In the present application, further, the heavy component removal product is dissolved with a solvent before being subjected to alkali washing, and the solvent is preferably toluene, xylene, ethylbenzene, cyclohexane, n-hexane, heptane, and further preferably ethylbenzene or toluene; the solvent usage amount is 0.5-5 times the mass of the heavy component removal organic phase, and the solution viscosity is <10 cp.

[0016] Further, the alkali solution used in the alkali washing can be an aqueous solution of an organic base or an inorganic base, and is preferably a solution of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, etc., with a concentration range of 1-40 wt%, and preferably 2-10 wt%.

[0017] The alkali solution usage amount is such that the molar ratio of the alkali in the alkali solution to the ethyl phenol is 1-1.2:1.

[0018] Further, the washing equipment type used in the alkali washing can be a stirred tank, a static mixer, a rotating disc extraction column, a packed column, etc., and is preferably a rotating disc extraction column.

[0019] In the present application, further, countercurrent washing is adopted in the water washing, and the metal ion content after the water washing is <10 ppm.

[0020] Further, the solvent is removed after the water washing, and the solvent can be reused, and the remaining organic phase is subjected to basic resin treatment to control the phenol content in the organic phase to be <10 ppm.

[0021] Further, ultraviolet light with a wavelength of 300-400 nm is used for light irradiation during the basic resin treatment.

[0022] The basic resin can be a macroporous basic styrene anion exchange resin.

[0023] In the present application, further, the organic phase over-based resin is continuously rectified, the absolute pressure is 0.5-10KPaA, the reflux ratio is 0.1-60, and the beta-phenylethanol is obtained from the side line of the column;

[0024] Further, the beta-phenylethanol is stripped by using water vapor, the purity of the product after stripping is >99.95%, the total impurity of the organic matter is <200ppm, the single impurity is <50ppm, and the content of the key impurity ethyl phenol is not detected;

[0025] Further, the amount of the water vapor used for stripping is 1-10 times of the mass of the beta-phenylethanol;

[0026] Further, the oxygen content of the system needs to be controlled to be <5ppm during stripping.

[0027] Further, the beta-phenylethanol product obtained by the present application has soft fragrance and no coking smell.

[0028] Compared with the prior art, the technical scheme of the present application has the following advantages:

[0029] 1) Compared with the chemical synthesis method for producing beta-phenylethanol, the process flow is simple, there is no reaction hazard, and the production cost is greatly reduced;

[0030] 2) By controlling the viscosity of the alkali washing organic phase and the "ultraviolet light + resin" scheme for removing phenol, the impurity content of the phenol entering the rectification system is controlled, and the product odor is well guaranteed by combining stripping. DETAILED DESCRIPTION

[0031] The present application will be further described by specific examples, and it should be noted that the following examples are only used for the purpose of illustration, and the content of the present application is not limited thereto.

[0032] The reagents and solvents used in the present application can be purchased from Aladdin Reagent Company.

[0033] Device waste liquid: Wanhua Chemical PO / SM device.

[0034] Example 1:

[0035] Waste liquid composition: light component (1%, mainly benzyl alcohol, phenylacetone, phenylacetaldehyde), beta-phenylethanol (50%), alpha-phenylethanol (7%), ethyl phenol (7%), heavy component (35%, mainly styrene polymer, condensed ring aromatic hydrocarbon and other substances).

[0036] Under the condition of absolute pressure 8KPa(A), the amount of the scraped plate feed is 1kg / hr, the tar, polymer and other impurities with large viscosity in the waste liquid are removed by the scraped plate liquid, and the scraped plate light component 636g / hr is obtained by the gas phase condensation of the scraped plate, and the styrene polymer, condensed ring aromatic hydrocarbon and other substances in the scraped plate light component are not detected;

[0037] The 1 kg of light component of the scraper was mixed with ethylbenzene in a mass ratio of 1:1 to obtain 2 kg of ethylbenzene solution of the light component, and the viscosity was 6 cp. The ethylbenzene solution of the light component was fed from the lower end of the rotating disc extraction tower, and 10 wt% of an aqueous sodium hydroxide solution was fed from the upper end of the rotating disc extraction tower. The molar ratio of sodium hydroxide to ethylphenol in the ethylbenzene solution was 1.05:1. The rotating disc extraction tower was six-stage washed. The ethylbenzene solution after alkaline washing was water-washed in a packed tower to remove residual alkali and phenol sodium salt in the organic phase. The mass ratio of the amount of water used to the ethylbenzene solution after alkaline washing was 1:1. The content of metal ions in the ethylbenzene solution after water washing was 5 ppm. The ethylbenzene solution after water washing was distilled to recover ethylbenzene. The distillation pressure was 10 KPA, and the temperature was 70°C. 989 g of ethylbenzene was recovered to obtain a heavy component. Then, the heavy component was passed through an 8 g column of basic resin D201 (Dandong Mingzhu) (the column height was 10 cm). The ultraviolet light wavelength was 330 nm. After passing through the resin, the content of phenol in the organic phase was reduced to 8 ppm. Then, the organic phase was rectified. The absolute pressure of rectification was 1 Kpa (A), and the reflux ratio was 50. Water, benzyl alcohol, acetophenone, phenylacetaldehyde, α-phenethyl alcohol and other light components were collected from the top of the column. 596 g of β-phenethyl alcohol was obtained from the side line of the column. The obtained β-phenethyl alcohol was stripped using water vapor. The amount of water vapor used was 1200 g, and the oxygen content of the system was 1 ppm. About 546 g of β-phenethyl alcohol was obtained (denoted as sample 1). The purity of the product was 99.97%. The total content of other organic matters was 176 ppm. The maximum single impurity was 28 ppm. Ethylphenol was not detected.

[0038] Example 2:

[0039] The composition of the waste liquid was as follows: light component (1%, mainly benzyl alcohol, acetophenone, phenylacetaldehyde), β-phenethyl alcohol (60%), α-phenethyl alcohol (3%), ethylphenol (6%), and heavy component (30%, mainly styrene polymer and condensed ring aromatic hydrocarbons).

[0040] Under the condition of an absolute pressure of 2 Kpa (A), the amount of the scraper feed was 1 kg / hr. The tar and polymer and other large- viscosity impurities in the waste liquid were removed by the liquid below the scraper. The light component of the scraper was obtained by gas-phase condensation of the scraper, and the content of styrene polymer and condensed ring aromatic hydrocarbons in the light component was not detected.

[0041] The scraper light component 1 kg is mixed with toluene according to the mass ratio 1:2 to obtain 3 kg of toluene solution of light component, the viscosity is 4 cp, the toluene solution of light component is fed from the lower end of the rotating disc extraction tower, 10% sodium hydroxide aqueous solution is fed from the upper end of the rotating disc extraction tower, the amount of sodium hydroxide is 1.1:1 in molar ratio with ethyl phenol in toluene solution, the rotating disc extraction tower is six-stage washing, the toluene solution after alkaline washing is water-washed in a packed tower to remove inorganic salts in the organic phase, the amount of water used is 1:1 in mass ratio with toluene solution, the content of metal ions in the toluene solution after water washing is 3 ppm; the toluene solution after water washing is distilled to recover toluene, the distillation pressure is 10 KPA, the temperature is 70 DEG C, 1986 g of toluene is recovered to obtain heavy component, then the heavy component is passed through 8 g of 201x7 strong basic styrene anion exchange resin (Dandong Mingzhu) column (column height 10 cm), the ultraviolet light wavelength is 380 nm, after passing through the resin, the content of phenol in the organic phase is reduced to 6 ppm, continuous rectification is carried out, the absolute pressure of rectification is 3 Kpa (A), the reflux ratio is 40; water, benzyl alcohol, acetophenone, phenylacetaldehyde, alpha-phenethyl alcohol and other light components are collected from the top of the tower, about 602 g of beta-phenethyl alcohol is obtained from the side line of the tower, the beta-phenethyl alcohol is stripped using water vapor, the amount of water vapor is 1000 g, the oxygen content of the system is 0.5 ppm, about 557 g of beta-phenethyl alcohol (marked as sample 2) is obtained, the product purity is 99.98%, the total content of other organic matters is 156 ppm, the maximum single impurity is 36 ppm, and ethyl phenol is not detected.

[0042] Comparative example 1 (without adjusting viscosity):

[0043] The composition of the waste liquid is: light component (1%, mainly benzyl alcohol, acetophenone, phenylacetaldehyde), beta-phenethyl alcohol (50%), alpha-phenethyl alcohol (7%), ethyl phenol (7%), and heavy component (35%, mainly styrene polymer, condensed ring aromatic hydrocarbon and other substances).

[0044] Under the condition of absolute pressure 8 Kpa (A), the amount of scraper feed is 1 kg / hr, the tar and polymer and other large viscosity impurities in the waste liquid are removed by the liquid under the scraper, the scraper gas phase condensation obtains 636 g / hr of light component, the content of styrene polymer, condensed ring aromatic hydrocarbon and other substances in the light component is not detected;

[0045] The light component (viscosity 30 cp) 1 kg of the scraper was directly subjected to alkaline washing: the light component was fed from the lower end of the rotating disc extraction column, 10% sodium hydroxide aqueous solution was fed from the upper end of the rotating disc extraction column, the amount of sodium hydroxide was 1.05:1 in molar ratio with ethyl phenol in the light component, the rotating disc extraction column was six-stage washing, the light component after alkaline washing was subjected to water washing in a packed column to remove inorganic salts in the organic phase, the amount of water used was 1:1 in mass ratio with the light component, the metal ion content of the light component after water washing was 15 ppm; the light component after water washing was passed through an 8 g basic resin D201 (Dandong Mingzhu) column (column height 10 cm) with ultraviolet light wavelength of 330 nm, then continuous rectification was carried out, the absolute pressure of rectification was 1 Kpa (A), the reflux ratio was 50; water, acetophenone, phenylacetaldehyde, α-phenyl ethanol and other light components were collected from the top of the column, about 558 g of β-phenyl ethanol was obtained from the side line of the column, the obtained β-phenyl ethanol was subjected to steam stripping with water vapor, the amount of water vapor was 650 g, the oxygen content of the system was 1 ppm, about 489 g of β-phenyl ethanol (labeled as sample 3) was obtained, the purity of the product was 99.91%, the ethyl phenol content was 26 ppm, the total content of other organic matters was 368 ppm, and the maximum single impurity was 46 ppm.

[0046] Comparative example 2 (without using ultraviolet light):

[0047] The composition of the waste liquid: light component (1%, mainly benzyl alcohol, acetophenone, phenylacetaldehyde), β-phenyl ethanol (50%), α-phenyl ethanol (7%), ethyl phenol (7%), heavy component (35%, mainly styrene polymer, condensed ring aromatic hydrocarbon and other substances).

[0048] Under the condition of absolute pressure 8 Kpa (A), the amount of scraper feed was 1 kg / hr, the tar and polymer and other impurities with large viscosity in the waste liquid were removed by the liquid under the scraper, the light component 636 g / hr was obtained by gas phase condensation of the scraper, and the styrene polymer, condensed ring aromatic hydrocarbon and other substances in the light component were not detected;

[0049] 1 kg of the light component was mixed with ethylbenzene at a mass ratio of 1:1 to obtain a 2 kg ethylbenzene solution of the light component with a viscosity of 6 cp. This light component ethylbenzene solution was fed into the bottom of a rotary extractor, while a 10 wt% sodium hydroxide aqueous solution was fed into the top. The molar ratio of sodium hydroxide to ethylphenol in the ethylbenzene solution was 1.05:1. The rotary extractor underwent a six-stage washing process. The ethylbenzene solution after alkaline washing was then washed with water in a packed column to remove inorganic salts from the organic phase. The water volume to ethylbenzene solution mass ratio was 1:1. The metal ion content in the washed ethylbenzene solution was 5 ppm. The washed ethylbenzene solution was then distilled to recover ethylbenzene at a pressure of 10 kPa and a temperature of 70°C. The heavy component was then passed through an 8g alkaline resin D201 (Dandong Mingzhu) column (10cm high). After passing through the resin, the phenol content in the organic phase was 18ppm. The organic phase was then subjected to distillation at an absolute pressure of 1kPa (A) and a reflux ratio of 50. The top of the column yielded water, acetophenone, phenylacetaldehyde, α-phenylethanol, and other light components. 569g of β-phenylethanol was obtained from the column side stream. The obtained β-phenylethanol was stripped with steam using 1200g of steam. The system oxygen content was 1ppm, yielding 497g of β-phenylethanol (referred to as sample 4). The product purity was 99.93%, the ethylphenol content was 3ppm, and the total content of other organic matter was 196ppm, with a maximum single impurity of 42ppm.

[0050] Comparative Example 3 (without resin):

[0051] Waste liquid composition: light components (1%, mainly benzyl alcohol, acetophenone, phenylacetaldehyde), β-phenylethanol (50%), α-phenylethanol (7%), ethylphenol (7%), heavy components (35%, mainly styrene polymers, polycyclic aromatic hydrocarbons, etc.).

[0052] Under an absolute pressure of 8 kPa(A), with a scraper feed rate of 1 kg / hr, tar, polymers and other impurities with high viscosity in the waste liquid are removed by scraper liquid removal. The scraper vapor phase condensation yields 636 g / hr of scraper light component. Styrene polymers, polycyclic aromatic hydrocarbons and other substances were not detected in the light component.

[0053] 1 kg of the light component was mixed with ethylbenzene at a mass ratio of 1:1 to obtain a 2 kg ethylbenzene solution of the light component with a viscosity of 6 cp. This light component ethylbenzene solution was fed into the bottom of a rotary extractor, while a 10 wt% sodium hydroxide aqueous solution was fed into the top. The molar ratio of sodium hydroxide to ethylphenol in the ethylbenzene solution was 1.08:1. The rotary extractor underwent a six-stage washing process. The ethylbenzene solution after alkaline washing was then washed with water in a packed column to remove inorganic salts from the organic phase. The water volume to ethylbenzene solution mass ratio was 1:1. The metal ion content in the washed ethylbenzene solution was 5 ppm. The washed ethylbenzene solution was then distilled to recover ethylbenzene. Distillation was carried out at a pressure of 10 kPa and a temperature of 70 °C to obtain heavy components with a phenol content of 38 ppm. The organic phase was then subjected to rectification at an absolute pressure of 6 kPa (A) and a reflux ratio of 30. Water, acetophenone, phenylacetaldehyde, α-phenylethanol, and other light components were collected from the top of the column. Approximately 571 g of β-phenylethanol was obtained from the side stream. The β-phenylethanol was stripped with steam at a rate of 800 g and an oxygen content of 1 ppm, yielding 502 g of β-phenylethanol (referred to as sample 5). The product purity was 99.92%, with other organic compounds totaling 298 ppm, a maximum single impurity of 45 ppm, and ethylphenol at 8 ppm.

[0054] The prepared samples were subjected to aroma evaluation. The evaluation method was to place 10g of the sample to be tested in a 20ml glass bottle, seal the bottle and wait 24 hours. After that, the bottle was opened and the aroma was evaluated. The initial aroma was detected 1-2 seconds after opening the bottle, the middle aroma was detected 5-20 seconds after opening the bottle, and the final aroma was detected 30-60 seconds after opening the bottle.

[0055] The results are as follows:

[0056]

[0057] The test results of the above examples and comparative examples show that the β-phenylethanol obtained by the method of the present invention has significant advantages over the prior art in the comparative examples, namely, simple operation and ease of industrialization.

[0058] The above description is merely an example of the embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A method for recovering β-phenylethanol from waste liquid produced by a PO / SM unit, comprising the following steps: (1) The waste liquid produced by the PO / SM unit is deweighted to obtain a deweighted component free of tar and polymer; the deweighting is performed using a vacuum scraped film evaporator at a pressure of 1-10 kPaA and a temperature of 100-150°C. (2) The de-weighted component obtained in step (1) is washed with alkali to obtain an organic phase in which most of the ethylphenol has been removed. Before alkali washing, the de-weighted component needs to be dissolved in a solvent. The solvent is selected from toluene, xylene, ethylbenzene, cyclohexane, n-hexane, and heptane. The alkali solution used for alkali washing is an aqueous solution of organic or inorganic alkali with a concentration range of 1 to 40% wt. (3) Wash the organic phase obtained in step (2) with water to obtain the organic phase; (4) The organic phase obtained in step (3) is subjected to alkaline resin to remove phenol, resulting in an organic phase with a phenol content of <10ppm; during the alkaline resin treatment, 300-400nm ultraviolet light is used for illumination. (5) The organic phase with a phenol content of <10ppm obtained in step (4) is subjected to distillation to obtain β-phenylethanol product.

2. The method according to claim 1, wherein, In step (2), the amount of solvent used is 0.5-5 times the mass of the de-recombined components, and the solution viscosity is <10cp.

3. The method according to claim 1, wherein, The alkaline solution used for alkaline washing is selected from potassium hydroxide, sodium hydroxide, and tetramethylammonium hydroxide solution.

4. The method according to claim 1 or 3, wherein, The amount of alkali solution used is such that the molar ratio of alkali to ethylphenol in the alkali solution is 1-1.2:

1.

5. The method according to claim 1, wherein, The water washing process uses countercurrent washing, and the metal ion content after washing is <10ppm.

6. The method according to claim 1, wherein, The alkaline resin in step (4) is a macroporous alkaline styrene-based anion exchange resin.

7. The method according to claim 1, wherein, The distillation process is carried out at an absolute pressure of 0.5–10 kPaA, with a reflux ratio of 0.1–60, and β-phenylethanol is extracted from the side stream of the column.

8. The method according to claim 7, wherein, The extracted β-phenylethanol was stripped using steam. Furthermore, the amount of stripping steam used is 1-10 times the mass of β-phenylethanol; Furthermore, the oxygen content of the system must be controlled to be less than 5 ppm during stripping.

Images