CN108129274B - MTBE prepared by reactive distillation and wastewater treatment method thereof - Google Patents
MTBE prepared by reactive distillation and wastewater treatment method thereof Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
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- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/01—Preparation of ethers
- C07C41/09—Preparation of ethers by dehydration of compounds containing hydroxy groups
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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- C02F1/26—Treatment of water, waste water, or sewage by extraction
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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- C02F9/00—Multistage treatment of water, waste water or sewage
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/01—Preparation of ethers
- C07C41/34—Separation; Purification; Stabilisation; Use of additives
- C07C41/38—Separation; Purification; Stabilisation; Use of additives by liquid-liquid treatment
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Abstract
The invention discloses a method for preparing MTBE (methyl tert-butyl ether) by reactive distillation and a wastewater treatment method thereof. Tert-butyl alcohol and methanol are used as etherification raw materials, wherein the tert-butyl alcohol is a byproduct in the production of propylene oxide by co-oxidation; the traditional reaction rectifying tower comprising a reaction section and a rectifying section is divided into two parts, the reaction section is carried outside the rectifying tower in a side reactor mode, and a plurality of side reactors can be adopted to ensure the conversion rate of raw materials; the generated etherification wastewater realizes impurity removal and extractant circulation after extraction and rectification. The problem of device shutdown caused by frequent catalyst replacement is solved and the conversion rate of TBA is improved. Through reactive distillation and extraction, the content of organic matters in the wastewater is reduced, so that the wastewater meets the water quality requirement of biochemical treatment.
Description
Technical Field
The invention relates to the technical field of catalytic reaction rectification and the field of wastewater treatment in the chemical field, in particular to a method for preparing MTBE (methyl tert-butyl ether) by reactive rectification and treating wastewater thereof.
Technical Field
MTBE (methyl tert-butyl ether) is a high-octane gasoline component, is an excellent gasoline high-octane additive and antiknock agent, and can also be used for preparing high-purity isobutene through decomposition.
The literature reports that MTBE is synthesized by using isobutene and methanol as raw materials and an acid catalyst, wherein the catalyst is most industrially used as a resin catalyst, and different synthetic routes are formed according to different sources of isobutene. As reported in patent CN102701919A, a process for producing MTBE by reacting mixed C4 with methanol with low isobutylene content; patent CN104876785A reports that the residual C4 extracted from butadiene is reacted with methanol to produce MTBE; patent CN104945228A reports that mixed tetracarbon hydrocarbons are subjected to a series of steps of hydrogenation, dehydrogenation, isomerization, etc. to form isobutene, and then etherified with methanol. The purpose of the above patents is to improve the utilization efficiency of the mixed C4 and increase the economic value.
However, since 2012, the production device for preparing propylene oxide by the co-oxidation method is put into production sequentially in China, the yield of the byproduct Tertiary Butyl Alcohol (TBA) is increased, and the yield of the tertiary butyl alcohol is excessive, so that the development of the process for generating MTBE by etherification of the tertiary butyl alcohol and methanol has a better prospect. Most of the conventional devices for preparing propylene oxide by co-oxidation adopt a plug flow reactor for production, and the MTBE etherification reaction is an equilibrium reaction, so that a large amount of unreacted alcohol is circulated, the energy consumption required by alcohol-water separation is high, and heavy component accumulation and other problems exist in recovered alcohol; and a large amount of organic matters exist in the wastewater, so that the COD is high and the biochemical treatment is difficult. The reaction rectification technology can not only improve the conversion rate of the tertiary butanol and reduce the energy consumption, but also reduce the residue of organic matters in the wastewater and improve the biodegradability of the wastewater.
The literature reports that the reactive distillation technology of MTBE mostly takes isobutene as a raw material. For example, patent CN204625508U discloses a reaction rectifying tower for preparing MTBE, and the apparatus includes several main parts, such as a pre-reactor, a rectifying tower, and a catalytic rectifying tower, to achieve deep conversion of isobutylene, but the existence of the catalytic rectifying tower still cannot get rid of the problem that the catalyst is difficult to replace in the conventional reaction rectifying process. Patent CN102423539A reports a reaction rectification process for separating a reaction section from a rectification section, the patent is heavier in weight, energy is saved, consumption is reduced, physical property difference of tert-butyl alcohol and isobutene is not considered, and high conversion rate of tert-butyl alcohol cannot be achieved by using the equipment.
Because the tert-butyl alcohol as a byproduct obtained in the preparation of the propylene oxide by the co-oxidation method contains a plurality of impurities, the impurities can enter waste water when the tert-butyl alcohol is used as a raw material to prepare the MTBE. The residue of light components in the wastewater can be reduced through a reactive distillation technology, but heavy component organic matters which are toxic to microorganisms still remain in the wastewater, and biochemical treatment can be carried out only after water quality indexes are adjusted through means such as water distribution, and the biodegradability of the wastewater is not obviously improved.
The industrial waste water treatment method mainly comprises an adsorption method, an incineration method, an ion exchange method, a steam stripping method, a chemical oxidation method and the like. For example, the fenton oxidation wastewater treatment process disclosed in chinese patent CN202898099U and CN103755007B, the diatomite-based adsorbent for wastewater treatment disclosed in chinese patent CN103432986A, the anion exchange resin for wastewater treatment disclosed in chinese patent CN103272654A, and the method for treating wastewater containing acid and ammonia by steam stripping disclosed in chinese patent CN 102320671B. The deep oxidation technology has more varieties, can reduce the COD of the tail water to a certain extent, but has lower reaction effectiveness and treatment efficiency and higher treatment cost; the membrane separation technology is a mature tail water deep treatment and recycling technology, but only relies on membrane equipment, so that the investment is large, the operation cost is high, and the membrane concentrated solution is easy to cause secondary pollution; the adsorption technology can be suitable for the requirements of advanced treatment of most industrial organic wastewater, but has the problems of high treatment cost, poor reproducibility and the like. The solvent extraction method has simple process, easy operation and high extraction efficiency, and commonly used extracting agents for the extraction method comprise dichloromethane, diisopropyl ether, methyl isobutyl ketone, petroleum ether, n-hexane and the like. In recent years, solvent extraction methods have been widely applied in the field of phenolic wastewater treatment in coal chemical industry, such as a coal chemical industry wastewater extraction dephenolization method disclosed in chinese patent CN101913718B and an oil-containing coal chemical industry wastewater extraction method disclosed in chinese patent CN104829025A, but the application of solvent extraction methods in the field of treatment of MTBE etherification wastewater is rarely reported.
In view of the above, a new method for preparing MTBE from tert-butyl alcohol by reactive distillation technology is needed, which solves the problem of catalyst replacement, improves the conversion rate of tert-butyl alcohol and effectively treats etherification wastewater thereof.
Disclosure of Invention
The invention aims to provide a method for preparing MTBE (methyl tert-butyl ether) by reactive distillation and a wastewater treatment method thereof, which solve the problem of device shutdown caused by frequent replacement of a catalyst due to the service life of the catalyst in a traditional reactive distillation tower, particularly when a resin catalyst is adopted, the service life is only 6-8 months, and the conversion rate of TBA is improved. Through reactive distillation and extraction, the content of organic matters in the wastewater is reduced, so that the wastewater meets the water quality requirement of biochemical treatment.
In order to achieve the above purpose, the technical scheme of the invention is as follows:
a treatment method for preparing MTBE (methyl tert-butyl ether) and wastewater thereof by reactive distillation comprises the following steps:
(1) tert-butyl alcohol and methanol are used as etherification raw materials, and the proportion of the tert-butyl alcohol to the methanol is 0.5-1: 1(wt.), wherein the tert-butyl alcohol is a byproduct in the preparation of propylene oxide by an oxidation method; a traditional reaction rectifying tower is divided into a reaction section and a rectifying section, raw materials of methanol and TBA are fed into the middle section of the rectifying tower, the reaction section is loaded outside the rectifying tower in a side reactor mode, one or more, preferably 1-3 side reactors can be carried, and the reaction section is connected with a heat exchanger through a compressor. Tert-butyl alcohol and methanol enter a side reactor through a rectifying tower to carry out etherification reaction in the presence of a catalyst; and (3) separating the reaction product in a rectifying tower to obtain MTBE, isobutene and unreacted methanol at the top of the tower and obtain etherification wastewater (the COD value of the wastewater is 30000-40000 mg/L) at the bottom of the tower.
The methanol feed position is below the tert-butanol feed position according to the boiling point difference, and the material mixing is carried out by rectification. One or more, preferably one to three, materials are extracted from the middle section of the tower and respectively enter the side reactor, and the discharged material of the side reactor returns to the middle section of the rectifying tower for separation. Preferably, the feeding position of the side reactor is separated from the rectifying tower kettle by 10-20 theoretical plates, and the discharging position of the side reactor is separated from the rectifying tower top by 10-20 theoretical plates, so that the TBA cannot fall back to the rectifying tower kettle or be carried to the tower top. The feeding position of the side reactor refers to the position of the material flow of the rectifying tower entering the side reactor and exiting the rectifying tower, and the discharging position of the side reactor refers to the position of the material flow of the side reactor entering the rectifying tower and entering the rectifying tower.
(2) The etherification wastewater is divided into an oil phase and an oil phase through extraction, the extraction agent is recycled through oil phase rectification, the low COD wastewater is obtained through water phase lightness removal, and the wastewater treatment mode is biochemical treatment.
In the method of the present invention, the TBA in step (1) contains various alcohol, aldehyde, ketone, acid and alkane impurities, preferably, the impurities in the TBA include, but are not limited to, isopropanol, isobutanol, acetaldehyde, acetone, isobutyric acid and isooctane.
In the method, the theoretical plate number of the rectifying tower in the step (1) is 40-80, the operation pressure at the top of the tower is 0.1-1 MPa (absolute pressure), the temperature of a tower kettle is 80-180 ℃, the temperature at the top of the tower is 40-90 ℃, and the reflux ratio is 5-30.
Further, the theoretical plate number of the rectifying tower in the step (1) is preferably 50-70, the operation pressure at the top of the rectifying tower is preferably 0.2-0.5 MPa (absolute pressure), the temperature of a tower kettle is preferably 120-160 ℃, the temperature at the top of the rectifying tower is preferably 50-80 ℃, and the reflux ratio is preferably 10-20.
In the method, the methanol feeding position in the rectifying tower is below the TBA feeding position, preferably, the methanol feeding position is at 40-60 theoretical plates, and the TBA feeding position is at 20-30 theoretical plates (the number of the theoretical plates is from top to bottom).
In the method, the number of the side reactors is 1-3, preferably 2-3, the temperature of the reactors is 90-200 ℃, the reaction pressure is 0.1-5 MPa (absolute pressure), the temperature of the reactors is preferably 100-150 ℃, and the reaction pressure is preferably 2-4 MPa (absolute pressure).
In the method of the invention, the catalyst is one or more of acidic resin catalyst, metal oxide, metal salt, zeolite molecular sieve, solid super acid and the like, and is preferably Rohm and Haas resin A-35 and A-45, Al2O3，AlPO4，H-ZSM-5，SO4 2-/ZrO2One or more of; the space velocity of the material in the side reactor is 1.5-2.5 h-1。
Preferably, the inlet/outlet position of the side reactor is positioned between 20 th theoretical plates and 60 th theoretical plates of the rectifying tower.
In the method of the invention, the pressure and the temperature of the side reactor and the rectifying tower are preferably matched by a compressor and a heat exchanger; meanwhile, the temperature and pressure coupling of the reaction and the rectification can be realized by adjusting the type of the catalyst according to different matching positions of the side reactor and the rectification tower.
In the method, the device for extraction in the step (2) can be one or more of an extraction tower, a mixer-settler, a static mixer and an oil-water separator, and preferably one or more of an extraction tower, a mixer-settler and an oil-water separator; the theoretical stage number of the extraction device is 1-10, preferably 1-5. The extractant can be one or more of methanol, dichloromethane, methyl tert-butyl ether, diisopropyl ether and methyl isobutyl ketone; preferably one or more of dichloromethane, methyl tert-butyl ether and diisopropyl ether. The mass ratio of the extracting agent to the waste water is 0.1: 1-2: 1, and the mass ratio of the extracting agent to the waste water is preferably 0.3: 1-1: 1. The COD value of the treated wastewater is 10000-13000 mg/L.
In the method, the extracted oil phase in the step (2) is sent to a solvent recovery tower, heavy oil at the bottom of the solvent recovery tower is sent to an incinerator for incineration treatment, and an extractant at the top of the solvent recovery tower is recycled; and (3) delivering the extracted water phase to a wastewater lightness-removing tower, delivering wastewater at the bottom of the wastewater lightness-removing tower to a water treatment unit for biochemical treatment, and delivering light components at the top of the wastewater lightness-removing tower to a solvent recovery tower. Preferably, the theoretical plate number of the wastewater light component removal tower is 10-40, the operation pressure is 0.01-0.2 MPa (absolute pressure), the tower top temperature is 50-110 ℃, and the tower kettle temperature is 80-120 ℃. The theoretical plate number of the solvent recovery tower is 10-50, the operation pressure is 0.01-0.2 MPa (absolute pressure), the tower top temperature is 30-80 ℃, and the tower kettle temperature is 60-150 ℃.
The invention has the positive effects that:
1. according to the invention, tert-butyl alcohol is used as a raw material for MTBE etherification, so that the problem of excess tert-butyl alcohol production can be solved, and the raw material source is more economic.
2. The reaction section is carried outside the rectifying tower in the form of a side reactor, and the high conversion rate of TBA can be achieved by adjusting the number of the side reactors; the form of the side reactor can also facilitate the replacement of the catalyst; the side reactor and the rectifying tower are coupled through temperature and pressure, so that the reaction and separation can be carried out under the optimal working condition, and the reaction and rectification efficiency is improved.
3. Compared with the PO/MTBE process by the prior co-oxidation method, the method for synthesizing MTBE by adopting the reactive distillation mode solves the problems of low single-pass conversion rate, large raw material circulation amount, heavy component accumulation and the like. The content of organic matters in the wastewater can be reduced by adopting a reactive distillation mode, so that the organic matters are prevented from entering the wastewater; and when extraction treatment is adopted, alkali is not needed to be added into the wastewater to adjust the pH value for demulsification, so that the process is simplified, and the cost is saved. Through the form of extraction, rectification can reduce waste water COD effectively, show the biodegradability that improves waste water, save the cost of waste water treatment, realize the discharge to reach standard or the retrieval and utilization of waste water, guaranteed the continuous steady operation of device.
4. The invention adopts a plurality of side reactors to adjust the type of the catalyst and realizes the coupling of temperature and pressure between reaction and rectification.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
The following is a more detailed description of the embodiments of the present invention with reference to the drawings and examples, all of which operate under the operating conditions of the above-described embodiments for the purpose of better understanding of the present invention. The examples given therefore do not limit the scope of the invention.
In the embodiment, Agilent gas chromatography is adopted to quantify raw materials and reaction liquid, and an Agilent HP-5ms chromatographic column is adopted; programmed heating, keeping the temperature at 50 ℃ for 2min, heating to 60 ℃ at 5 ℃/min, keeping the temperature for 1min, heating to 100 ℃ at 40 ℃/min, keeping the temperature for 1min, heating to 200 ℃ at 10 ℃/min, keeping the temperature for 1min, heating to 280 ℃ at 40 ℃/min, and keeping the temperature for 5 min. The Hash BOD/COD water quality analyzer detects the BOD/COD value of the wastewater.
Example 1
As shown in FIG. 1, a rectifying tower with 68 theoretical plates is adopted, matched with 2 side reactors and connected with a compressor through a heat exchanger. Tert-butyl alcohol and methanol are fed into the rectifying tower at theoretical plates 27 and 57 respectively, and the tertiary-butyl alcohol is a byproduct in the preparation of propylene oxide by a co-oxidation method, wherein the byproduct comprises about 1 wt.% of impurities, such as isobutyric acid, isobutanol, isopropanol and the like. In the reactor-2, a material is led out from the 35 th theoretical plate of the rectifying tower to be used as a feed material, and the discharge position is the 20 th theoretical plate; in the reactor-1, a material is led out from the 54 th theoretical plate of the rectifying tower to be used as a feed material, and the discharge position is at the 40 th theoretical plate.
The two reactors both adopt Rohm and Haas A-35 resin catalyst, the pressure of the reactors is 2MPa, and the temperature is 100 ℃. The mass ratio of the tertiary butanol to the methanol is 1:1, and the retention time of the materials in each reactor is 30 min. The top pressure of the rectifying tower is 0.2MPa, the pressure of the bottom of the rectifying tower is 0.25MPa, the temperature of the bottom of the rectifying tower is maintained at 125 ℃, the temperature of the top of the rectifying tower is 60 ℃, the reflux ratio is 15, and the yield ratio D/F at the top of the rectifying tower is 0.875.
After the device is stabilized, sampling analysis is carried out on the top and the bottom of the rectifying tower, wherein the water content in the bottom of the tower is 99.27 wt%, the tert-butyl alcohol content in the bottom of the tower is 0.42 wt%, and the methanol content in the bottom of the tower is 0.27 wt%; the top of the column had an isobutylene content of 4.31 wt%, an MTBE content of 60.65 wt%, a methanol content of 34.75 wt%, a TBA content of 0.11 wt%, and a water content of 0.08 wt%. The TBA conversion was 99.70%, the isobutylene selectivity was 9.96%, and the MTBE selectivity was 89.85%.
The COD value of the produced wastewater is 30000mg/L, and the B/C value of the ratio of the biological oxygen consumption to the chemical oxygen consumption is 0.1. The extraction device is an extraction tower, the number of extraction theoretical stages is 2, and the mass ratio of the MTBE serving as an extractant to the wastewater is 0.3: 1. The bottom of the extraction device obtains an extraction water phase, the extraction water phase enters a wastewater light component removal tower, the theoretical plate number of the wastewater light component removal tower is 10, the operating pressure is 0.1MPa (absolute pressure), the tower top temperature is 98.8 ℃, the tower kettle temperature is 103.0 ℃, wastewater at the bottom of the wastewater light component removal tower is conveyed to a water treatment unit for biochemical treatment, and light components at the top of the wastewater light component removal tower are conveyed to a solvent recovery tower; the extraction oil phase is obtained at the top of the extraction device, and is mixed with the light components at the top of the wastewater light component removal tower and then is conveyed to a solvent recovery tower for rectification treatment, the theoretical plate number of the solvent recovery tower is 10, the operating pressure is 0.1MPa (absolute pressure), the temperature at the top of the tower is 53.3 ℃, the temperature at the bottom of the tower is 101.0 ℃, the heavy oil at the bottom of the solvent recovery tower is conveyed to an incinerator for incineration treatment, and the extractant at the top of the solvent recovery tower is returned to the wastewater extraction tower for extraction.
And (3) detection: the treated wastewater is detected by a Hash BOD/COD water quality analyzer, the COD value is 12000mg/L, and the B/C value is 0.5.
Example 2
On the basis of example 1, the mass ratio of tert-butanol to methanol was changed to 3:4, and the other reaction and rectification parameters were unchanged, with a D/F of 0.86.
After the device is stabilized, sampling analysis is carried out on the top and the bottom of the rectifying tower, wherein the water content in the bottom of the tower is 99.13 wt%, the tert-butyl alcohol content in the bottom of the tower is 0.51 wt%, and the methanol content in the bottom of the tower is 0.28 wt%; the top of the column had an isobutylene content of 8.46 wt%, an MTBE content of 65.17 wt%, a methanol content of 25.83 wt%, a TBA content of 0.31 wt%, and a water content of 0.10 wt%. TBA conversion was 99.41%, isobutylene selectivity was 16.94%, and MTBE selectivity was 82.79%.
The COD value of the produced wastewater is 35000mg/L, and the B/C value is 0.15. The extraction device is a multi-stage oil-water separator, the theoretical stage number of the extraction device is 1, and the mass ratio of the extracting agent to the wastewater is 1: 1; the theoretical plate number of the wastewater light component removal tower is 20, the operation pressure is 0.1MPa (absolute pressure), the tower top temperature is 99.1 ℃, and the tower kettle temperature is 103.0 ℃; the theoretical plate number of the solvent recovery tower is 20, the operation pressure is 0.1MPa (absolute pressure), the tower top temperature is 52.8 ℃, and the tower kettle temperature is 105.0 ℃.
And (3) detection: the COD value of the wastewater after detection and treatment is 11000mg/L, and the B/C value is 0.5.
Example 3
On the basis of example 1, the catalyst in the reactor-1 was replaced with H-ZSM-5, and the temperature of the reactor-1 was adjusted to 150 ℃ and the pressure was adjusted to 3 MPa. The other reaction and rectification parameters were unchanged, and D/F was 0.875.
After the device is stabilized, sampling analysis is carried out on the top and the bottom of the rectifying tower, wherein the water content in the bottom of the tower is 99.32 wt%, the tert-butyl alcohol content in the bottom of the tower is 0.19 wt%, and the methanol content in the bottom of the tower is 0.23 wt%; the top of the column had an isobutylene content of 6.48 wt%, an MTBE content of 57.17 wt%, a methanol content of 35.93 wt%, a TBA content of 0.09 wt%, and a water content of 0.11 wt%. The TBA conversion was 99.80%, the isobutylene selectivity was 15.07%, and the MTBE selectivity was 84.68%.
The COD value of the produced wastewater is 38000mg/L, and the B/C value is 0.13. The extraction device is a multi-stage mixing clarifier, the theoretical stage number of the extraction device is 2, and the mass ratio of the extracting agent to the waste water is 0.5: 1; the theoretical plate number of the wastewater light component removal tower is 15, the operation pressure is 0.1MPa (absolute pressure), the tower top temperature is 99.0 ℃, and the tower kettle temperature is 104.0 ℃; the theoretical plate number of the solvent recovery tower is 20, the operation pressure is 0.1MPa (absolute pressure), the tower top temperature is 53.0 ℃, and the tower kettle temperature is 108.0 ℃.
And (3) detection: the COD value of the treated wastewater is 13000mg/L, and the B/C value is 0.6.
Example 4
On the basis of example 1, after running for 1000 hours continuously, sampling analysis is carried out on the top and the bottom of the rectifying tower, wherein the water content in the bottom of the tower is 99.11 wt%, the tertiary butanol content in the bottom of the tower is 0.57 wt%, and the methanol content in the bottom of the tower is 0.19 wt%; the top of the column had an isobutylene content of 4.57 wt%, an MTBE content of 60.16 wt%, a methanol content of 34.88 wt%, a TBA content of 0.17 wt%, and a water content of 0.07 wt%. The TBA conversion was 99.56%, the isobutene selectivity was 10.65%, and the MTBE selectivity was 89.28%.
After long-period continuous operation, the catalyst still has higher activity.
After the generated wastewater is subjected to extraction and lightness removing treatment, the COD value is stabilized at 10000-13000 mg/L, and the B/C is stabilized at 0.5-0.6.
Claims (16)
1. A method for preparing MTBE by reactive distillation and treating wastewater thereof comprises the following steps:
(1) tert-butyl alcohol and methanol are used as etherification raw materials and are respectively fed into the middle section of a rectifying tower, two side reactors are carried outside the rectifying tower and are connected with the rectifying tower through a compressor and a heat exchanger, and the tert-butyl alcohol and the methanol enter the side reactors through the rectifying tower to carry out etherification reaction in the presence of a catalyst; separating the reaction product in a rectifying tower to obtain MTBE, isobutene and unreacted methanol at the top of the tower and waste water at the bottom of the tower;
(2) separating the wastewater in the tower bottom of the rectifying tower into an oil phase and an oil phase by extraction, rectifying the oil phase to realize the recycling of an extracting agent, and removing light from the water phase to obtain low-COD wastewater;
the number of theoretical plates of the rectifying tower is 68, one side reactor is fed from the 35 th theoretical plate of the rectifying tower, and the discharge position is the 20 th theoretical plate; the other side reactor is fed from the 54 th theoretical plate of the rectifying tower, and the discharging position is at the 40 th theoretical plate.
2. The process of claim 1, wherein the tert-butanol is a by-product of the co-oxidation process to produce propylene oxide and contains alcohol, aldehyde, ketone, acid and alkane impurities.
3. The method according to claim 2, wherein the tert-butanol is a byproduct from the production of propylene oxide by the co-oxidation process, and contains isopropanol, isobutanol, acetaldehyde, acetone, isobutyric acid, and isooctane.
4. The method according to claim 1 or 2, characterized in that the operating pressure at the top of the rectifying tower is 0.1-1 MPa; the temperature of the tower kettle is 80-180 ℃; the temperature at the top of the tower is 40-90 ℃, and the reflux ratio is 5-30.
5. The method according to claim 4, characterized in that the operating pressure at the top of the rectifying tower is 0.2-0.5 MPa; the temperature of the tower kettle is 120-160 ℃; the temperature at the top of the tower is 50-80 ℃, and the reflux ratio is 10-20.
6. The process according to any one of claims 1 to 3, wherein the rectifying column of step (1) has a methanol feed position below the t-butanol feed position.
7. The method as claimed in claim 6, wherein the rectifying column of step (1) has a methanol feeding position at 40 to 60 theoretical plates and a tert-butanol feeding position at 20 to 30 theoretical plates.
8. The process according to any one of claims 1 to 3, wherein the side reactor reaction temperature in step (1) is 90 to 200 ℃; the reaction pressure is 0.1-5 MPa.
9. The method according to claim 8, wherein the side reactor reaction temperature in the step (1) is 100-150 ℃; the reaction pressure is 2-4 MPa.
10. The process of any one of claims 1 to 3, wherein the catalyst of step (1) is one or more of an acidic resin catalyst, a metal oxide, a metal salt, a zeolite molecular sieve, and a solid super acid.
11. The method of claim 10, wherein the catalyst of step (1) is a Rohm and Haas A-35, A-45 resin, Al2O3，AlPO4H-ZSM-5 and SO4 2-/ZrO2One or more of (a).
12. The method according to any one of claims 1 to 3, wherein the extracting agent used in the extraction in the step (2) is one or more of methanol, dichloromethane, methyl tert-butyl ether, diisopropyl ether and methyl isobutyl ketone, and the mass ratio of the extracting agent to the waste water is 0.1: 1-2: 1.
13. The method of claim 12, wherein the mass ratio of extractant to wastewater is 0.3: 1-1: 1.
14. the method according to claim 1, wherein the extraction device in the step (2) is one or more of an extraction tower, a mixer-settler, a static mixer and an oil-water separator, and the number of theoretical stages of the extraction device is 1-10.
15. The method according to any one of claims 1 to 3, wherein the extracted oil phase in the step (2) is sent to a solvent recovery tower, heavy oil at the bottom of the solvent recovery tower is sent to an incinerator for incineration treatment, and an extractant at the top of the solvent recovery tower is recycled.
16. The method according to any one of claims 1 to 3, wherein the extracted water phase in the step (2) is sent to a wastewater lightness-removing column, wastewater at the bottom of the wastewater lightness-removing column is sent to a water treatment unit for biochemical treatment, and light components at the top of the wastewater lightness-removing column are sent to a solvent recovery column.
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| CN114100527A (en) * | 2020-09-01 | 2022-03-01 | 中国石油化工股份有限公司 | Reactive distillation device and method for producing peroxycarboxylic acid |
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