CN111574479A - Refining process of propylene oxide - Google Patents
Refining process of propylene oxide Download PDFInfo
- Publication number
- CN111574479A CN111574479A CN202010535213.XA CN202010535213A CN111574479A CN 111574479 A CN111574479 A CN 111574479A CN 202010535213 A CN202010535213 A CN 202010535213A CN 111574479 A CN111574479 A CN 111574479A
- Authority
- CN
- China
- Prior art keywords
- tower
- propylene
- temperature
- propylene oxide
- column
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 title claims abstract description 63
- 238000007670 refining Methods 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims abstract description 32
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims abstract description 60
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims abstract description 60
- 238000000926 separation method Methods 0.000 claims abstract description 42
- 239000002904 solvent Substances 0.000 claims abstract description 40
- 238000011084 recovery Methods 0.000 claims abstract description 25
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims abstract description 18
- 229910052938 sodium sulfate Inorganic materials 0.000 claims abstract description 18
- 235000011152 sodium sulphate Nutrition 0.000 claims abstract description 18
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 16
- 238000001704 evaporation Methods 0.000 claims abstract description 16
- 230000008020 evaporation Effects 0.000 claims abstract description 16
- 239000002351 wastewater Substances 0.000 claims abstract description 15
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000006227 byproduct Substances 0.000 claims abstract description 9
- 238000002425 crystallisation Methods 0.000 claims abstract description 4
- 230000008025 crystallization Effects 0.000 claims abstract description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical group OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 111
- 239000000243 solution Substances 0.000 claims description 20
- 239000000047 product Substances 0.000 claims description 17
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 15
- 239000012670 alkaline solution Substances 0.000 claims description 15
- 239000000463 material Substances 0.000 claims description 15
- 239000007791 liquid phase Substances 0.000 claims description 12
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 10
- 238000000605 extraction Methods 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- 239000000872 buffer Substances 0.000 claims description 6
- 239000012295 chemical reaction liquid Substances 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 6
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 5
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 4
- 238000000895 extractive distillation Methods 0.000 claims description 4
- 239000003513 alkali Substances 0.000 claims description 3
- 238000006735 epoxidation reaction Methods 0.000 claims description 3
- 238000006386 neutralization reaction Methods 0.000 claims description 3
- 238000010992 reflux Methods 0.000 claims description 3
- 239000007788 liquid Substances 0.000 abstract description 4
- 238000007254 oxidation reaction Methods 0.000 abstract description 3
- 230000003647 oxidation Effects 0.000 abstract description 2
- 239000002699 waste material Substances 0.000 abstract 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 30
- 239000012535 impurity Substances 0.000 description 16
- TZIHFWKZFHZASV-UHFFFAOYSA-N methyl formate Chemical compound COC=O TZIHFWKZFHZASV-UHFFFAOYSA-N 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 9
- 239000000126 substance Substances 0.000 description 8
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 7
- 150000001299 aldehydes Chemical class 0.000 description 7
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 7
- HWOWEGAQDKKHDR-UHFFFAOYSA-N 4-hydroxy-6-(pyridin-3-yl)-2H-pyran-2-one Chemical compound O1C(=O)C=C(O)C=C1C1=CC=CN=C1 HWOWEGAQDKKHDR-UHFFFAOYSA-N 0.000 description 4
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- -1 aldehyde ketone Chemical class 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000003456 ion exchange resin Substances 0.000 description 3
- 229920003303 ion-exchange polymer Polymers 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000007127 saponification reaction Methods 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 description 2
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000004280 Sodium formate Substances 0.000 description 1
- IKHGUXGNUITLKF-XPULMUKRSA-N acetaldehyde Chemical compound [14CH]([14CH3])=O IKHGUXGNUITLKF-XPULMUKRSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000003637 basic solution Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000013064 chemical raw material Substances 0.000 description 1
- XENVCRGQTABGKY-ZHACJKMWSA-N chlorohydrin Chemical compound CC#CC#CC#CC#C\C=C\C(Cl)CO XENVCRGQTABGKY-ZHACJKMWSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000007857 hydrazones Chemical class 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- HLBBKKJFGFRGMU-UHFFFAOYSA-M sodium formate Chemical compound [Na+].[O-]C=O HLBBKKJFGFRGMU-UHFFFAOYSA-M 0.000 description 1
- 235000019254 sodium formate Nutrition 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D301/00—Preparation of oxiranes
- C07D301/32—Separation; Purification
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
- C01D5/16—Purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D301/00—Preparation of oxiranes
- C07D301/02—Synthesis of the oxirane ring
- C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
- C07D301/12—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with hydrogen peroxide or inorganic peroxides or peracids
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
- C07D303/02—Compounds containing oxirane rings
- C07D303/04—Compounds containing oxirane rings containing only hydrogen and carbon atoms in addition to the ring oxygen atoms
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Epoxy Compounds (AREA)
Abstract
The invention discloses a refining process of propylene oxide, which comprises pre-separation, propylene stripping, propylene oxide refining, solvent recovery and sodium sulfate evaporation crystallization. The invention develops a new refining process aiming at the problems that the separation process of the propylene oxide produced by the direct oxidation method of the hydrogen peroxide is complex, the alkaline waste water can not be reasonably utilized and the like, and particularly, the sodium sulfate byproduct is obtained by adding the sulfuric acid into the alkaline waste water, so that the resources are reasonably utilized, the economic benefit is improved, and the discharge of the alkaline waste liquid is greatly reduced.
Description
Technical Field
The invention relates to the technical field of preparation of propylene oxide, and particularly relates to a refining process of propylene oxide.
Background
Propylene oxide is a very important chemical raw material, and the production technology mainly comprises a chlorohydrin method, a co-oxidation method and a hydrogen peroxide direct oxidation method (HPPO), wherein the most promising HPPO process is mainly due to high atom utilization rate and environmental friendliness, and conforms to the concept of green chemistry.
The separation and purification of products in the HPPO process is one of the key technologies. GB/T14491-2015 industrial propylene oxide makes a clear requirement on the quality of propylene oxide: qualified epoxypropane product has purity of 99.80 omega%, water content less than or equal to 500ppm, and aldehyde impurities less than or equal to 200 ppm; the high-quality product of the propylene oxide has the purity of 99.95 omega percent, the water content is less than or equal to 200ppm, and the aldehyde impurities are less than or equal to 500 ppm; few high-end applications even require less than 10ppm of aldehyde impurities. The propylene oxide reaction liquid contains propylene oxide, propylene, a solvent, water, propylene glycol and other byproducts, and in industrial production, aldehyde and ketone impurities in the HPPO reaction liquid are often as high as 100-2000 ppm, separation and purification are difficult, and the product quality can be ensured only by effectively removing the impurities in the reaction liquid. Methyl formate can be effectively removed by reacting with alkaline substances to generate salts and methanol, and aldehyde ketone impurities can be removed by reacting hydrazine or hydrazine hydrate and other substances to generate insoluble substances.
Chinese patent CN200810053897.9 discloses a method for purifying propylene oxide, wherein an extractant is added above the feeding point of crude propylene oxide on a rectifying tower, and the extractant is an alkaline solution containing ammonia or ammonium salt. The patent does not mention alkaline wastewater treatment.
Chinese patent CN201110434173.0 discloses a method for refining and purifying propylene oxide, wherein crude propylene oxide enters a reactor filled with basic ion exchange resin for reaction, methyl formate and acetaldehyde in the crude propylene oxide are removed, and then the crude propylene oxide is further rectified to obtain high-purity propylene oxide. This method uses a reactor packed with a basic ion exchange resin, and is higher in cost and increased in reactor equipment investment compared with a basic solution.
Chinese patent CN201510468132.1 discloses a method for purifying propylene oxide, in which crude propylene oxide is mixed with alkaline solution, methyl formate as an impurity reacts to produce methanol and sodium formate, the reacted solution is mixed with hydrazine solution, and acetaldehyde, acetone, etc. are reduced to hydrazone heavy components and water. The patent does not mention the problem of wastewater treatment.
The above patents all utilize alkaline substances to purify propylene oxide, the alkaline ion exchange resin reactor has high cost, and the alkaline solution does not consider the problem of wastewater treatment and utilization.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a propylene oxide refining process aiming at the defects of the prior art, so as to achieve the purposes of optimizing the propylene oxide refining process, reasonably utilizing the resources of wastewater, reducing the wastewater discharge and ensuring that the process is more environment-friendly.
The technical scheme is as follows: the invention relates to a refining process of propylene oxide, which comprises the following steps:
s1, mixing hydrogen peroxide, a solvent and propylene, and then carrying out epoxidation reaction, and recovering the obtained reaction liquid through propylene to obtain a liquid-phase product;
s2, feeding the liquid-phase product into a pre-separation tower, obtaining crude propylene oxide at the tower top, and feeding the tower bottom material flow into a solvent recovery system;
s3, feeding the crude propylene oxide into a propylene stripping tower, refluxing one part of the liquid phase at the top of the tower into the pre-separation tower, separating propylene from the other part of the liquid phase through a propylene separating tank, and compressing the propylene to enter a propylene circulating system; mixing the crude propylene oxide flowing out of the tower bottom with an alkaline solution in a crude propylene oxide buffer tank;
s4, feeding the crude epoxypropane mixed by the alkali liquor into an epoxypropane refining tower for extraction rectification, wherein an extracting agent is water, hydrazine hydrate is added into the tower to react with aldehyde ketone impurities to generate insoluble substances, the insoluble substances are precipitated on a filler, an oxygen-containing gas is discharged from a tower top stream to obtain an epoxypropane product, a tower bottom stream is purified again by a re-separation tower and then returned to the epoxypropane refining tower from the tower top of the re-separation tower, and the crude solvent of the tower bottom stream of the re-separation tower is fed into a solvent recovery tower;
s5, the solvent separated by the solvent recovery tower enters a solvent circulation system from the tower top, the alkaline waste water of the tower bottom material flow of the solvent recovery tower is added with sulfuric acid for neutralization, and the neutralized sodium sulfate solution enters an evaporation kettle for evaporation and crystallization to obtain a byproduct sodium sulfate.
Preferably, in S1, the solvent is methanol.
Preferably, in S2, the top pressure of the pre-separation tower is 0.05-0.5MPa, the temperature of the tower bottom is 90-120 ℃, and the extraction temperature at the tower top is 60-90 ℃.
Preferably, in S3, the top pressure of the propylene stripping tower is 0.05-0.5MPa, the temperature of the tower bottom is 60-150 ℃, and the extraction temperature at the tower top is 60-120 ℃.
Preferably, in S4, the top pressure of the propylene oxide refining tower is 0.05-0.5MPa, the temperature of the tower bottom is 60-150 ℃, and the extraction temperature at the tower top is 30-90 ℃.
Preferably, in S4, the top pressure of the re-separation tower is 0.05-0.5MPa, the temperature of the tower bottom is 60-150 ℃, and the extraction temperature at the tower top is 30-90 ℃.
Preferably, in S4, the top pressure of the solvent recovery tower is 0.05-0.5MPa, the temperature of the tower bottom is 120-180 ℃, and the extraction temperature at the tower top is 90-150 ℃.
Preferably, in S5, the temperature of the evaporation kettle is 120-200 ℃.
Preferably, in S3, the alkaline solution is sodium hydroxide solution or sodium bicarbonate solution
Compared with the prior art, the invention has the beneficial effects that: the invention effectively removes ester impurities by using the alkaline solution to improve the product purity, simultaneously treats and utilizes the alkaline wastewater to obtain a sodium sulfate byproduct, reduces the discharge of the alkaline wastewater, and generates economic and social benefits.
Drawings
FIG. 1 is a process flow diagram of an embodiment of the present invention.
In the attached figure, 1-a pre-separation tower, 2-a propylene stripping tower, 3-a circulating propylene compressor, 4-a propylene oxide refining tower, 5-a re-separation tower, 6-a solvent recovery tower and 7-an evaporation kettle.
Detailed Description
Referring to fig. 1, the present invention provides a process for refining propylene oxide, the process comprising the steps of:
s1, mixing hydrogen peroxide, a solvent and propylene, and then carrying out epoxidation reaction, and recovering the obtained reaction liquid through propylene to obtain a liquid-phase product;
s2, feeding the liquid-phase product into a pre-separation tower, obtaining crude propylene oxide at the tower top, and feeding the tower bottom material flow into a solvent recovery system;
s3, feeding the crude propylene oxide into a propylene stripping tower, refluxing one part of the liquid phase at the top of the tower into the pre-separation tower, separating propylene from the other part of the liquid phase through a propylene separating tank, and compressing the propylene to enter a propylene circulating system; mixing the crude propylene oxide flowing out of the tower bottom with an alkaline solution in a crude propylene oxide buffer tank;
s4, feeding the crude epoxypropane mixed by the alkali liquor into an epoxypropane refining tower for extraction rectification, wherein an extracting agent is water, hydrazine hydrate is added into the tower to react with aldehyde ketone impurities to generate insoluble substances, the insoluble substances are precipitated on a filler, an oxygen-containing gas is discharged from a tower top stream to obtain an epoxypropane product, a tower bottom stream is purified again by a re-separation tower and then returned to the epoxypropane refining tower from the tower top of the re-separation tower, and the crude solvent of the tower bottom stream of the re-separation tower is fed into a solvent recovery tower;
s5, the solvent separated by the solvent recovery tower enters a solvent circulation system from the tower top, the alkaline waste water of the tower bottom material flow of the solvent recovery tower is added with sulfuric acid for neutralization, and the neutralized sodium sulfate solution enters an evaporation kettle for evaporation and crystallization to obtain a byproduct sodium sulfate.
The technical solution of the present invention is described in detail below with reference to specific examples and drawings, but the scope of the present invention is not limited to the examples.
Example 1
The present invention is further described in the context of a process for purifying propylene oxide, which is carried out in an industrial plant of 10 ten thousand tons PO/year. Referring to FIG. 1, the S1 is 9.8t/h propylene and 16.4t/h hydrogen peroxide with mass concentration of 50%, and the reaction solution is obtained after the reaction with methanol as solvent and passing through a propylene recovery system. S1 mass flow rate was 68.4t/h, with the following composition:
the operating conditions of the preseparation column 1 are as follows: the tower top temperature: 60 ℃; pressure at the top of the column: 0.05 MPa; temperature at the bottom of the column: 90 ℃; containing 17 theoretical plates. The crude propylene oxide S2 having a mass flow rate of 20.6t/h flowed out from the top of the column contained PO of 65.7% by mass, methanol of 31.4% by mass, water of 2.5% by mass and propylene of 0.2% by mass. S6 having a bottom stream mass flow rate of 49.1t/h contained 73.4% by mass of methanol, 24.0% by mass of water, and the like.
The operating conditions of the propylene stripper 2 were as follows: the tower top temperature: 60 ℃; pressure at the top of the column: 0.05 MPa; temperature at the bottom of the column: 60 ℃; containing 5 theoretical plates. S4, which flowed out from the top at a mass flow rate of 1.3t/h, contained PO at a mass concentration of 84.0%, methanol at a mass concentration of 12.5%, propylene at a mass concentration of 2.7%, water at a mass concentration of 0.6%, and the like. S4 is mixed with S2 at the top of the pre-separation tower 1, and then a part of S3 with the mass flow rate of 1.2t/h is separated by a liquid separation tank 3 and returned to the propylene stripping tower 2, the other part of S3 becomes S5 with the mass flow rate of 0.02t/h after being compressed by a circulating propylene compressor 3 and enters a propylene circulating system, the outlet pressure of the propylene compressor 3 is 26bar, S3 contains PO with the mass concentration of 84.9%, methanol with the mass concentration of 12.7%, propylene with the mass flow rate of 1.6% and the like, and S5 contains propylene with the mass concentration of 73.9%, PO with the mass concentration of 25.2% and the like. S7 having a bottom stream mass flow rate of 19.3t/h contained PO at a mass concentration of 64.4%, methanol at a mass concentration of 32.6%, and the like. S7 is mixed with alkaline solution in a crude propylene oxide buffer tank for reaction, a small amount of methyl formate impurities are subjected to saponification reaction to obtain S8 with mass flow rate of 19.3t/h, wherein the S8 contains PO with mass concentration of 64.7%, methanol with mass concentration of 32.7% and the like, the alkaline solution is 0.013t/a of sodium hydroxide solution with mass concentration of 30% and 0.003t/h of sodium bicarbonate solution with mass concentration of 30%, and S8 enters a PO refining tower 4 for extractive distillation.
The operating conditions of the PO refining column 4 are as follows: the tower top temperature: 30 ℃; pressure at the top of the column: 0.05 MPa; temperature at the bottom of the column: 60 ℃; containing 60 theoretical plates. In addition to S8, the feed material also includes a stream of desalted water with a mass flow rate of 0.75t/h and a stream of hydrazine hydrate, which reacts with the aldehyde impurities for separation. The bottom S10 flows out to enter a re-separation tower 5, and the top S11 flows out of the re-separation tower 5 and returns to a PO refining tower 4. And discharging oxygen-containing gas from the tower top material flow of the PO refining tower 4 to obtain a PO product, wherein the mass flow of the S9 is 12.5t/h, and the PO mass purity is 99.97%. S12 with a mass flow rate of 7.6t/h and S12 containing 83.4% by mass of methanol, 16.5% by mass of water and the like are discharged from the bottom of the re-separation column 5 and introduced into a solvent recovery column 6.
The operating conditions of the solvent recovery column 6 were as follows: the tower top temperature: 90 ℃; pressure at the top of the column: 0.05 MPa; temperature at the bottom of the column: 120 ℃; containing 15 theoretical plates. S13 containing methanol with a mass concentration of 97.2% and water with a mass flow rate of 6.5t/h flowing out from the top of the tower enters a methanol circulation system, S14 containing methanol with a mass concentration of 2.3% and water with a mass concentration of 97.7% flowing out from the bottom of the tower with a mass flow rate of 1.1t/h flows out from the bottom of the tower. Concentrated sulfuric acid with the mass flow rate of 0.005t/h reacts with S14 alkaline water to obtain an S15 sodium sulfate aqueous solution.
S15 enters an evaporation kettle 7 to separate sodium sulfate and wastewater, the operation temperature of the evaporation kettle 7 is 120 ℃, a byproduct sodium sulfate with the yield of 0.0075t/h is obtained, and the wastewater with the mass flow of 0.003t/h is subjected to subsequent treatment.
Example 2
The technology of the present invention is further described by taking a 20 ten thousand ton PO/year industrial apparatus as an example. Referring to FIG. 1, the reaction solution after the S1 reaction of 19.5t/h propylene and 32.7t/h hydrogen peroxide with the mass concentration of 50% in methanol as a solvent and passing through a propylene recovery system. S1 mass flow rate was 136.8t/h, with the following composition:
the operating conditions of the preseparation column 1 are as follows: the tower top temperature: 90 ℃; pressure at the top of the column: 0.5 MPa; temperature at the bottom of the column: 120 ℃; containing 17 theoretical plates. The crude propylene oxide S2 having a mass flow rate of 41.4t/h flowed out from the top of the column contained PO at a mass concentration of 66.5%, methanol at a mass concentration of 30.6%, water at a mass concentration of 2.4%, propylene at a mass concentration of 0.2%, and the like. S6 having a mass flow rate of 98.5t/h contained 73.5% by mass of methanol, 23.9% by mass of water, and the like in the bottom stream.
The operating conditions of the propylene stripper 2 were as follows: the tower top temperature: 120 ℃; pressure at the top of the column: 0.5 MPa; temperature at the bottom of the column: 150 ℃; containing 5 theoretical plates. S4, which flowed out of the top of the column at a mass flow rate of 3.1t/h, contained PO at a mass concentration of 84.5%, methanol at a mass concentration of 12.2%, propylene at a mass concentration of 2.5%, water at a mass concentration of 0.5%, and the like. S4 is mixed with S2 at the top of the pre-separation tower 1, and then a part of S3 with the mass flow rate of 3t/h is separated by a liquid separation tank 3 and returned to the propylene stripping tower 2, the other part of S3 becomes S5 with the mass flow rate of 0.04t/h after being compressed by a circulating propylene compressor 3 and enters a propylene circulating system, the outlet pressure of the propylene compressor 3 is 26bar, S3 contains PO with the mass concentration of 85.3%, methanol with the mass concentration of 12.3%, propylene with the mass concentration of 1.6% and the like, and S5 contains propylene with the mass concentration of 73.9%, PO with the mass concentration of 25.2% and the like. S7 having a bottom stream mass flow rate of 38.3t/h contained PO at a mass concentration of 65.1%, methanol at a mass concentration of 31.3%, and the like. S7 is mixed with alkaline solution in a crude propylene oxide buffer tank for reaction, a small amount of methyl formate impurities are subjected to saponification reaction to obtain S8 with the mass flow rate of 38.2t/h, wherein the S8 contains 65.3% PO, 32.2% methanol and the like, the alkaline solution is 0.025t/a of 30% sodium hydroxide solution and 0.006t/h of 30% sodium bicarbonate solution, and the S8 enters a PO refining tower 4 for extractive distillation.
The operating conditions of the PO refining column 4 are as follows: the tower top temperature: 90 ℃; pressure at the top of the column: 0.5 MPa; temperature at the bottom of the column: 150 ℃; containing 60 theoretical plates. In addition to S8, the feed material also includes a stream of desalted water with a mass flow rate of 1.5t/h and a stream of hydrazine hydrate, and the hydrazine hydrate reacts with the aldehyde impurities to be separated conveniently. The bottom S10 flows out to enter a re-separation tower 5, and the top S11 flows out of the re-separation tower 5 and returns to a PO refining tower 4. And discharging oxygen-containing gas from the tower top material flow of the PO refining tower 4 to obtain a PO product, wherein the mass flow of the S9 is 24.9t/h, and the PO mass purity is 99.97%. S12 with a mass flow rate of 14.8t/h and S12 containing 83.2% by mass of methanol, 16.7% by mass of water and the like are discharged from the bottom of the re-separation column 5 and introduced into a solvent recovery column 6.
The operating conditions of the solvent recovery column 6 were as follows: the tower top temperature: 150 ℃; pressure at the top of the column: 0.5 MPa; temperature at the bottom of the column: 180 ℃; containing 15 theoretical plates. S13 containing methanol with a mass concentration of 97.3% and water with a mass flow rate of 12.6t/h flowing out from the top of the tower enters a methanol circulating system, S14 containing methanol with a mass concentration of 1.2% and water with a mass concentration of 98.8% flowing out from the bottom of the tower with a mass flow rate of 2.2t/h flows out from the bottom of the tower. Concentrated sulfuric acid with the mass flow rate of 0.01t/h reacts with S14 alkaline water to obtain an S15 sodium sulfate aqueous solution.
S15 enters an evaporation kettle 7 to separate sodium sulfate and wastewater, the operation temperature of the evaporation kettle 7 is 200 ℃, a byproduct sodium sulfate with the yield of 0.015t/h is obtained, and the wastewater with the mass flow of 0.006t/h is subjected to subsequent treatment.
Example 3
The present invention is further illustrated by taking a 40 ten thousand ton PO/year industrial plant as an example. Referring to FIG. 1, the S1 is a reaction solution obtained by reacting 38.9t/h of propylene and 65.3t/h of hydrogen peroxide with the mass concentration of 50% in methanol as a solvent and passing the reaction solution through a propylene recovery system. S1 mass flow 273.7t/h with the following composition:
the operating conditions of the preseparation column 1 are as follows: the tower top temperature: 68 ℃; pressure at the top of the column: 0.25 MPa; temperature at the bottom of the column: 100 ℃; containing 17 theoretical plates. The crude propylene oxide S2 having a mass flow rate of 83.5t/h flowed out from the top of the column contained PO of 67.6% by mass, methanol of 29.5% by mass, water of 2.3% by mass and propylene of 0.2% by mass. S6 having a bottom stream mass flow rate of 197.8t/h contained methanol having a mass concentration of 73.6%, water having a mass concentration of 23.9%, and the like.
The operating conditions of the propylene stripper 2 were as follows: the tower top temperature: 100 ℃; pressure at the top of the column: 0.25 MPa; temperature at the bottom of the column: 120 ℃; containing 5 theoretical plates. S4, which flowed out from the top at a mass flow rate of 7.8t/h, contained PO at a mass concentration of 85.1%, methanol at a mass concentration of 11.8%, propylene at a mass concentration of 2.3%, water at a mass concentration of 0.5%, and the like. S4 is mixed with S2 at the top of the pre-separation tower 1, and then a part of S3 with the mass flow rate of 7.7t/h is separated by a liquid separation tank 3 and returned to the propylene stripping tower 2, the other part of S3 becomes S5 with the mass flow rate of 0.08t/h after being compressed by a circulating propylene compressor 3 and enters a propylene circulating system, the outlet pressure of the propylene compressor 3 is 26bar, S3 contains PO with the mass concentration of 85.8%, methanol with the mass concentration of 12.0%, propylene with the mass concentration of 1.5% and the like, and S5 contains propylene with the mass concentration of 73.9%, PO with the mass concentration of 25.2% and the like. S7 having a bottom stream mass flow rate of 75.7t/h contained PO at a mass concentration of 65.8%, methanol at a mass concentration of 31.3%, and the like. S7 is mixed and reacted with alkaline solution in a crude propylene oxide buffer tank, a small amount of methyl formate impurities are subjected to saponification reaction to obtain S8 with mass flow rate of 75.5t/h, wherein the S8 contains PO with mass concentration of 66.0%, methanol with mass concentration of 31.4% and the like, the alkaline solution is sodium hydroxide solution with mass concentration of 30% 0.05t/a and sodium bicarbonate solution with mass concentration of 30% 0.01t/h, and S8 enters a PO refining tower 4 for extractive distillation.
The operating conditions of the PO refining column 4 are as follows: the tower top temperature: 60 ℃; pressure at the top of the column: 0.25 MPa; temperature at the bottom of the column: 110 ℃; containing 60 theoretical plates. In addition to S8, the feed also includes a stream of desalted water at a mass flow rate of 3t/h and a stream of hydrazine hydrate, which reacts with the aldehyde impurities to facilitate separation. The bottom S10 flows out to enter a re-separation tower 5, and the top S11 flows out of the re-separation tower 5 and returns to a PO refining tower 4. And discharging oxygen-containing gas from the tower top material flow of the PO refining tower 4 to obtain a PO product, wherein the mass flow of the S9 is 49.8t/h, and the PO mass purity is 99.97%. S12 with a mass flow rate of 28.6t/h and S12 containing 82.8% by mass of methanol, 17.1% by mass of water and the like are discharged from the bottom of the re-separation column 5 and introduced into a solvent recovery column 6.
The operating conditions of the solvent recovery column 6 were as follows: the tower top temperature: 120 ℃; pressure at the top of the column: 0.25 MPa; temperature at the bottom of the column: 150 ℃; containing 15 theoretical plates. S13 containing methanol with a mass concentration of 97.1% and water with a mass flow rate of 24.4t/h flowing out from the top of the tower enters a methanol circulating system, S14 containing methanol with a mass concentration of 0.6% and water with a mass concentration of 99.4% flowing out from the bottom of the tower with a mass flow rate of 4.3t/h flows out from the bottom of the tower. Concentrated sulfuric acid with the mass flow rate of 0.02t/h reacts with S14 alkaline water to obtain an S15 sodium sulfate aqueous solution.
S15 enters an evaporation kettle 7 to separate sodium sulfate and wastewater, the operation temperature of the evaporation kettle 7 is 160 ℃, the byproduct sodium sulfate with the yield of 0.03t/h is obtained, and the wastewater with the mass flow of 0.01t/h is subjected to subsequent treatment.
As noted above, while the present invention has been shown and described with reference to certain preferred embodiments, it is not to be construed as limited thereto. Various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (9)
1. A process for refining propylene oxide, comprising the steps of:
s1, mixing hydrogen peroxide, a solvent and propylene, and then carrying out epoxidation reaction, and recovering the obtained reaction liquid through propylene to obtain a liquid-phase product;
s2, feeding the liquid-phase product into a pre-separation tower, obtaining crude propylene oxide at the tower top, and feeding the tower bottom material flow into a solvent recovery system;
s3, feeding the crude propylene oxide into a propylene stripping tower, refluxing one part of the liquid phase at the top of the tower into the pre-separation tower, separating propylene from the other part of the liquid phase through a propylene separating tank, and compressing the propylene to enter a propylene circulating system; mixing the crude propylene oxide flowing out of the tower bottom with an alkaline solution in a crude propylene oxide buffer tank;
s4, feeding the crude epoxypropane mixed by the alkali liquor into an epoxypropane refining tower for extractive distillation, discharging oxygen-containing gas from a tower top material flow to obtain an epoxypropane product, re-purifying a tower bottom material flow by a re-separation tower, returning the tower top material flow from the re-separation tower to the epoxypropane refining tower, and feeding a crude solvent of the tower bottom material flow of the re-separation tower into a solvent recovery tower;
s5, the solvent separated by the solvent recovery tower enters a solvent circulation system from the tower top, the alkaline waste water of the tower bottom material flow of the solvent recovery tower is added with sulfuric acid for neutralization, and the neutralized sodium sulfate solution enters an evaporation kettle for evaporation and crystallization to obtain a byproduct sodium sulfate.
2. The process of claim 1, wherein in S1, the solvent is methanol.
3. The process as claimed in claim 1, wherein in S2, the top pressure of the pre-separation tower is 0.05-0.5MPa, the temperature of the bottom of the tower is 90-120 ℃, and the temperature of the top of the tower is 60-90 ℃.
4. The process of claim 1, wherein in S3, the top pressure of the propylene stripping tower is 0.05-0.5MPa, the temperature of the bottom of the tower is 60-150 ℃, and the temperature of the top of the tower is 60-120 ℃.
5. The process of claim 1, wherein in S4, the top pressure of the propylene oxide refining tower is 0.05-0.5MPa, the temperature of the tower bottom is 60-150 ℃, and the temperature of the top extraction of the tower is 30-90 ℃.
6. The process of claim 1, wherein in S4, the top pressure of the re-separation column is 0.05 to 0.5MPa, the bottom temperature of the column is 60 to 150 ℃, and the top temperature of the column is 30 to 90 ℃.
7. The process as claimed in claim 1, wherein in S4, the top pressure of the solvent recovery column is 0.05-0.5MPa, the temperature in the bottom of the column is 120-180 ℃, and the temperature at the top of the column is 90-150 ℃.
8. The process as claimed in claim 1, wherein in S5, the temperature of the evaporation kettle is 120-200 ℃.
9. The process of claim 1, wherein in S3, the alkaline solution is sodium hydroxide solution or sodium bicarbonate solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010535213.XA CN111574479A (en) | 2020-06-12 | 2020-06-12 | Refining process of propylene oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010535213.XA CN111574479A (en) | 2020-06-12 | 2020-06-12 | Refining process of propylene oxide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111574479A true CN111574479A (en) | 2020-08-25 |
Family
ID=72119989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010535213.XA Pending CN111574479A (en) | 2020-06-12 | 2020-06-12 | Refining process of propylene oxide |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111574479A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103172594A (en) * | 2011-12-22 | 2013-06-26 | 中国石油化工股份有限公司 | Method for refining and purifying propylene oxide |
| CN104650008A (en) * | 2015-02-13 | 2015-05-27 | 南京航空航天大学 | Technique and system for preparing propylene oxide by directly oxidizing propylene with oxygen and hydrogen |
| CN106397364A (en) * | 2015-08-03 | 2017-02-15 | 中国石油化工股份有限公司 | Purifying apparatus for epoxypropane |
| CN107286119A (en) * | 2016-04-12 | 2017-10-24 | 中国石油化工股份有限公司 | The process for purification of expoxy propane |
-
2020
- 2020-06-12 CN CN202010535213.XA patent/CN111574479A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103172594A (en) * | 2011-12-22 | 2013-06-26 | 中国石油化工股份有限公司 | Method for refining and purifying propylene oxide |
| CN104650008A (en) * | 2015-02-13 | 2015-05-27 | 南京航空航天大学 | Technique and system for preparing propylene oxide by directly oxidizing propylene with oxygen and hydrogen |
| CN106397364A (en) * | 2015-08-03 | 2017-02-15 | 中国石油化工股份有限公司 | Purifying apparatus for epoxypropane |
| CN107286119A (en) * | 2016-04-12 | 2017-10-24 | 中国石油化工股份有限公司 | The process for purification of expoxy propane |
Non-Patent Citations (1)
| Title |
|---|
| 梁朝林等, 中国石化出版社, pages: 177 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| IE45681B1 (en) | Production of urea | |
| US4012443A (en) | Integrated urea-ammonia process | |
| CN110003136A (en) | A kind of method and apparatus using aldehyde ketone impurity in high effective additives removing HPPO technique | |
| CN110922292B (en) | Preparation method of chloromethane | |
| CN210085332U (en) | Device for removing aldehyde ketone impurities in HPPO (high performance liquid oxygen peroxide) process by using efficient auxiliary agent | |
| CN112237749A (en) | Device and method for synthesizing trioxymethylene by rectifying through salt effect reaction | |
| CN111470992A (en) | Clean process method for continuously synthesizing glycine | |
| CN110803999A (en) | Production process and equipment system for improving quality and yield of cyclohexanone-oxime | |
| US2807574A (en) | Treatment of unreacted ammonia in the manufacture of urea | |
| CN111574479A (en) | Refining process of propylene oxide | |
| US4440954A (en) | Process for the purification of p-aminophenol | |
| CN105399066B (en) | A kind of method for improving ketazine process hydrazine hydrate yield | |
| CN212293381U (en) | Propylene oxide refining device | |
| CN103987683B (en) | Comprise the preparation method of the mixture of hexalin and pimelinketone | |
| CN113860995B (en) | Recovery treatment process and treatment device for waste liquid produced in production of acetochlor | |
| US7045110B1 (en) | High yield co-production of anhydrous hydrogen bromide and sodium bisulfate | |
| US20240076277A1 (en) | System and method for preparing epoxy chloropropane | |
| US11608274B2 (en) | Alkali metal cyanide production | |
| CN211497430U (en) | Equipment system for improving quality and yield of cyclohexanone oxime | |
| US3335183A (en) | Preparation of oximes | |
| US2931704A (en) | Sodium dichromate production | |
| JP5648304B2 (en) | Method for producing acrylonitrile | |
| US20240240330A1 (en) | Process for producing lithium hydroxide | |
| WO2023136195A1 (en) | Method for manufacturing lithium hydroxide | |
| US3197505A (en) | Process for the preparation of cyclohexanoneoxime from the oxidation products of cyclohexane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200825 |