CN114763318A - Method and device for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation method - Google Patents
Method and device for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation method Download PDFInfo
- Publication number
- CN114763318A CN114763318A CN202110041480.6A CN202110041480A CN114763318A CN 114763318 A CN114763318 A CN 114763318A CN 202110041480 A CN202110041480 A CN 202110041480A CN 114763318 A CN114763318 A CN 114763318A
- Authority
- CN
- China
- Prior art keywords
- tower
- cyclohexanol
- cyclohexanone
- lightness
- heat
- 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.)
- Granted
Links
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 title claims abstract description 206
- HPXRVTGHNJAIIH-UHFFFAOYSA-N cyclohexanol Chemical compound OC1CCCCC1 HPXRVTGHNJAIIH-UHFFFAOYSA-N 0.000 title claims abstract description 146
- 238000000034 method Methods 0.000 title claims abstract description 58
- 238000005984 hydrogenation reaction Methods 0.000 title claims abstract description 38
- 230000032050 esterification Effects 0.000 title claims abstract description 25
- 238000005886 esterification reaction Methods 0.000 title claims abstract description 25
- YYLLIJHXUHJATK-UHFFFAOYSA-N Cyclohexyl acetate Chemical compound CC(=O)OC1CCCCC1 YYLLIJHXUHJATK-UHFFFAOYSA-N 0.000 claims abstract description 49
- 238000006356 dehydrogenation reaction Methods 0.000 claims abstract description 45
- 238000000926 separation method Methods 0.000 claims abstract description 38
- HFYLJNMQIGJQOQ-UHFFFAOYSA-N cyclohexanol;ethanol Chemical compound CCO.OC1CCCCC1 HFYLJNMQIGJQOQ-UHFFFAOYSA-N 0.000 claims abstract description 28
- 238000011084 recovery Methods 0.000 claims abstract description 27
- 239000000203 mixture Substances 0.000 claims abstract description 17
- 239000007788 liquid Substances 0.000 claims abstract description 9
- 239000000463 material Substances 0.000 claims abstract description 8
- 239000000295 fuel oil Substances 0.000 claims abstract description 7
- 239000003921 oil Substances 0.000 claims description 22
- 238000006243 chemical reaction Methods 0.000 claims description 10
- 238000010992 reflux Methods 0.000 claims description 10
- HGCIXCUEYOPUTN-UHFFFAOYSA-N cyclohexene Chemical compound C1CCC=CC1 HGCIXCUEYOPUTN-UHFFFAOYSA-N 0.000 description 16
- 238000004519 manufacturing process Methods 0.000 description 14
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 13
- 238000007670 refining Methods 0.000 description 13
- -1 alcohol ketone Chemical class 0.000 description 11
- 238000007257 deesterification reaction Methods 0.000 description 9
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 8
- 230000003647 oxidation Effects 0.000 description 7
- 238000007254 oxidation reaction Methods 0.000 description 7
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 6
- 150000002148 esters Chemical class 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 230000008878 coupling Effects 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 4
- 238000005859 coupling reaction Methods 0.000 description 4
- 238000005265 energy consumption Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- BUCJHJXFXUZJHL-UHFFFAOYSA-N 1-ethylcyclohexan-1-ol Chemical compound CCC1(O)CCCCC1 BUCJHJXFXUZJHL-UHFFFAOYSA-N 0.000 description 3
- WKYYYUWKFPFVEY-UHFFFAOYSA-N 2-ethylcyclohexan-1-one Chemical compound CCC1CCCCC1=O WKYYYUWKFPFVEY-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000036571 hydration Effects 0.000 description 3
- 238000006703 hydration reaction Methods 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 2
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 2
- GKRALBJDXHXFNB-UHFFFAOYSA-N butoxycyclohexane Chemical compound CCCCOC1CCCCC1 GKRALBJDXHXFNB-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- WHMORFGZTZGKOM-UHFFFAOYSA-N cyclohexanol;cyclohexyl acetate Chemical compound OC1CCCCC1.CC(=O)OC1CCCCC1 WHMORFGZTZGKOM-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- JBKVHLHDHHXQEQ-UHFFFAOYSA-N epsilon-caprolactam Chemical compound O=C1CCCCCN1 JBKVHLHDHHXQEQ-UHFFFAOYSA-N 0.000 description 2
- 239000012847 fine chemical Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 150000002576 ketones Chemical class 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 229920002292 Nylon 6 Polymers 0.000 description 1
- 229920002302 Nylon 6,6 Polymers 0.000 description 1
- 241000183024 Populus tremula Species 0.000 description 1
- 235000011037 adipic acid Nutrition 0.000 description 1
- 239000001361 adipic acid Substances 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 208000012839 conversion disease Diseases 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000006200 vaporizer Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
- C07C45/32—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen
- C07C45/37—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of >C—O—functional groups to >C=O groups
- C07C45/38—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of >C—O—functional groups to >C=O groups being a primary hydroxyl group
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A method and a device for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation method comprise an ethanol-cyclohexanol separation tower, a cyclohexanol lightness-removing tower, a dehydrogenation reactor, a cyclohexanone lightness-removing tower, a cyclohexanone tower, a cyclohexanol tower and a cyclohexyl acetate recovery tower which are sequentially connected, wherein an outlet at the top of the cyclohexanol lightness-removing tower is connected to the ethanol-cyclohexanol separation tower in a return way; and the outlet at the top of the cyclohexanol tower is connected to the inlet of the dehydrogenation reactor. Sending the ethanol-cyclohexanol mixture into an ethanol-cyclohexanol separation tower, sending the tower bottom liquid of the ethanol-cyclohexanol separation tower into a cyclohexanol lightness-removing tower, returning the distillate of the cyclohexanol lightness-removing tower to the ethanol-cyclohexanol separation tower, sending the tower bottom liquid of the cyclohexanol lightness-removing tower into a dehydrogenation reactor, sending the materials after dehydrogenation reaction into a cyclohexyl acetate recovery tower after sequentially passing through the cyclohexanone lightness-removing tower, the cyclohexanone tower and a cyclohexanol tower, returning the distillate of the cyclohexyl acetate recovery tower to a cyclohexyl acetate hydrogenation section, and taking the tower bottom liquid of the cyclohexyl acetate recovery tower out for sale as fuel oil.
Description
Technical Field
The invention belongs to the technical field of cyclohexanone production, and particularly relates to a method and a device for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation method.
Background
Cyclohexanone is an important fine chemical, primarily used in the production of caprolactam and adipic acid, which are precursors of nylon-6 and nylon-66, respectively. Besides being used for the preparation of amide-based products, cyclohexanone is also used as an organic solvent and for the preparation of fine chemicals. The industrial preparation method of cyclohexanone generally comprises three cyclohexane oxidation methods, a phenol hydrogenation method and a cyclohexene hydration method.
Among the industrial processes for preparing cyclohexanone, the cyclohexane oxidation process has been the main production process, and has the disadvantages that the conversion rate of cyclohexane is very low, and the single process is only 3.5 mol% -4.5 mol%, and cyclohexane needs to be recycled, distilled, separated and then reacted, so that the energy consumption of the whole system is high, and air is introduced in the process to form an explosive mixture, so that the risk is high. The phenol hydrogenation method is emphasized by the good quality of cyclohexanone, simple process and low energy consumption, and the route is mainly limited by the productivity and market price of phenol. The cyclohexene hydration method is an environment-friendly cyclohexanone process route, the method is high in reaction selectivity, three wastes are hardly discharged in the process, but the defects of low reaction conversion rate, high requirement on cyclohexene purity and the like exist, if a high-silicon ZSM-5 catalyst is adopted and stays in two slurry reactors connected in series, the single-pass conversion rate of the cyclohexene is only 10-12.5 mol%, and a large amount of cyclohexene needs to be circularly separated and returned.
Compared with the technical route for preparing cyclohexanol by cyclohexene hydration, the esterification hydrogenation method is used as a newly developed 4 th cyclohexanone production technical route, has high conversion per pass and high yield of cyclohexene esterification and cyclohexyl acetate hydrogenation reactions, can co-produce anhydrous ethanol, and is about to enter into industrial design at present. Research in the process packet development stage shows that the conversion rate of the ester hydrogenation catalyst is reduced at the later stage of the service life, about 0.1-1.0 wt% of ester is carried into cyclohexanol, and a conventional negative pressure separation scheme is adopted, so that the rapid accumulation of cyclohexyl acetate in a dehydrogenation and alcohol ketone refining system is found, and the feeding load of an alcohol ketone rectification system and a dehydrogenation reaction system is increased; meanwhile, how to effectively integrate heat in the whole production process and reducing energy consumption are the key for reducing production cost.
Chinese patent publication No. CN108003017A proposes a method for separating cyclohexyl acetate, a method for producing cyclohexanol, and a method for producing cyclohexanol. Specifically, after the cyclohexyl acetate is hydrogenated, the mixed product of ethanol and cyclohexanol is passed through an ethanol separation tower, a cyclohexanol lightness-removing tower and a cyclohexanol deesterification tower to obtain refined cyclohexanol, the refined cyclohexanol enters a dehydrogenation reactor, the dehydrogenation reactor obtains an alcohol-ketone mixture, the alcohol-ketone mixture is sequentially sent to the lightness-removing tower, the cyclohexanone tower and the cyclohexanol tower for refining, and the refined circulating cyclohexanol obtained from the cyclohexanol tower is merged and enters the dehydrogenation reactor. In the scheme, the cyclohexanol deesterification tower is operated under micro-positive pressure, the cyclohexanol tower is operated under negative pressure, and the operating pressure is 3KPa (absolute).
Chinese patent publication No. CN106518640B provides a method for efficiently separating and refining cyclohexanone products, specifically a method for refining cyclohexanone while removing light components in a single cyclohexanone tower. The cyclohexanone tower is a rectifying tower, and specifically comprises the following steps: dehydrating crude alcohol ketone generated by cyclohexanol dehydrogenation, sending the dehydrated crude alcohol ketone into the cyclohexanone tower, condensing gas phase at the tower top, refluxing part of the dehydrated crude alcohol ketone to the tower top, and extracting and removing the rest of the dehydrated crude alcohol ketone serving as light component impurities; and liquid-phase cyclohexanone product is collected from the side line of the cyclohexanone tower. The invention overcomes the defects of the prior art, achieves the aim of separating and refining the cyclohexanone, reduces the energy consumption, reduces the loss amount of the cyclohexanone, and reduces the investment and the operation cost of the device.
Chinese patent publication No. CN206680412U provides a double-effect rectification apparatus for separating cyclohexanone from oil, specifically, a gas phase in a light column is used as a heat source for rectification in a ketone column, and the ketone column does not use steam as the heat source any more, thereby reducing steam consumption in the separation process and effectively reducing production cost.
Chinese patent publication No. CN203976674U provides a cyclohexanol separation apparatus in the production process of cyclohexanone by cyclohexene process. In particular to a double-effect parallel rectification process which adopts two separation towers to replace the prior single-tower separation process. The heat load of a reboiler at the bottom of the tower required by the cyclohexanol separation system is reduced by 30% compared with the single-tower separation, and the heat load of a condenser at the top of the tower is reduced by 15% compared with the single-tower separation.
Chinese patent publication No. CN 106187721 provides a process system for dehydrogenation reaction of cyclohexanol by heating heat-conducting oil with steam. The process system improves the stability of hot oil temperature control, improves the energy utilization rate, saves a natural gas heating furnace and achieves the aim of reducing the heating cost.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide a method and a device for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation method, which combine and separate light and heavy components generated by cyclohexyl acetate hydrogenation reaction and cyclohexanol dehydrogenation reaction, simplify the flow, reduce the refining process of cyclohexanol, solve the problem of accumulation of cyclohexyl acetate in cyclohexanol circulation, further adopt a heat integration technology and energy cascade utilization, and reduce steam consumption.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
a method for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation method comprises the steps of sending an ethanol-cyclohexanol mixture obtained by hydrogenating cyclohexyl acetate into an ethanol-cyclohexanol separation tower for rectification separation, extracting distillate of the ethanol-cyclohexanol separation tower, sending tower bottom liquid of the ethanol-cyclohexanol separation tower into a cyclohexanol lightness-removing tower for rectification separation, returning the distillate of the cyclohexanol lightness-removing tower into the ethanol-cyclohexanol separation tower, sending the tower bottom liquid of the cyclohexanol lightness-removing tower into a dehydrogenation reactor for reaction, sending materials after dehydrogenation reaction into a cyclohexyl acetate recovery tower for rectification separation after sequentially passing through the cyclohexanone lightness-removing tower, the cyclohexanone tower and the cyclohexanol tower, returning the distillate of the cyclohexyl acetate recovery tower to a cyclohexyl acetate hydrogenation working section, and extracting the tower bottom liquid of the cyclohexyl acetate recovery tower as fuel oil for sale.
Preferably, the outer tube superheated steam is used as a heat source, firstly sent to a heat conduction oil heat exchanger to exchange heat with heat conduction oil of dehydrogenation reaction, then sent to a reboiler at the bottom of the cyclohexanol tower to supply heat, sent to a reboiler at the bottom of the cyclohexyl acetate recovery tower to supply heat, and sent to other processes in the rest part; sending distillate of the cyclohexanone lightness-removing tower to a reboiler at the bottom of the cyclohexanone tower for heat exchange and then extracting; the distillate of the cyclohexanol tower is firstly sent to a reboiler at the bottom of the cyclohexanone lightness-removing tower for heat exchange and then sent to a dehydrogenation reactor.
Preferably, the pressure of the superheated steam is 3.5-4.5 MPa, the temperature is 390-430 ℃, the pressure after heat exchange with the heat conduction oil is 3.5-4.5 MPa, and the temperature is 250-300 ℃.
Preferably, the dehydrogenation reactor is a tubular reactor, the inner diameter of the tubular reactor is 30-50 mm, the length of the tubular reactor is 5000-8000 mm, the shell pass of the heat conducting oil is taken, the tube pass of cyclohexanol is taken, the pressure difference of the tubular reactor is 5-30 KPa, the reaction temperature is 220-260 ℃, and the pressure is 5-30 KPa (shown in the table).
Preferably, the cyclohexanone lightness-removing tower is a packed tower, the number of tower plates is 15-40, the operation pressure is 20-50 KPa (absolute), the reflux ratio is 350-450, the tower top temperature is 110-135 ℃, and the tower kettle temperature is 130-140 ℃.
Preferably, the cyclohexanone tower is a packed tower, the number of tower plates is 60-80, and the operating pressure is 2-5 KPa (absolute); the reflux ratio is 2-4, the temperature at the top of the tower is 50-60 ℃, and the temperature at the bottom of the tower is 80-100 ℃.
Preferably, the cyclohexanol tower is a packed tower, the number of tower plates is 40-60, the reflux ratio is 1-3, and the operating pressure is 5-30 KPa (shown in the table); the temperature of the top of the tower is 162-175 ℃, and the temperature of the bottom of the tower is 170-185 ℃.
Preferably, the cyclohexyl acetate recovery tower is a packed tower, the number of tower plates is 20-40, the reflux ratio is 1-3, the operation pressure is 5-30 KPa (absolute), the temperature of the top of the tower is 100-130 ℃, and the temperature of a tower kettle is 150-180 ℃.
In the invention, ethanol-cyclohexanol mixture (containing a small amount of cyclohexyl acetate which is not completely reacted, light components of by-products, heavy components and the like) obtained by hydrogenating the cyclohexyl acetate is passed through an ethanol-cyclohexanol separation tower to obtain crude ethanol and crude cyclohexanol, the light components of the crude cyclohexanol are removed through a cyclohexanol lightness-removing tower, the cyclohexyl acetate is not required to be removed through positive pressure operation of the cyclohexanol lightness-removing tower, but is directly sent to a dehydrogenation reactor to be reacted to obtain crude ketol, the crude ketol is respectively treated through the cyclohexanone lightness-removing tower, the cyclohexanone tower and the cyclohexanol tower to remove the light and heavy components in materials after dehydrogenation reaction to obtain qualified cyclohexanone and circulating cyclohexanol, the cyclohexanol tower adopts a mixture containing the cyclohexyl acetate and the heavy components obtained from a tower kettle after positive pressure operation, and finally the mixture is passed through a small cyclohexyl acetate recovery tower operated under negative pressure to separate and recover the cyclohexyl acetate and return to a cyclohexyl acetate hydrogenation refining section, and (4) taking heavy components in the tower bottom out as fuel oil.
The invention also provides a device for preparing cyclohexanone from the crude cyclohexanol obtained by the esterification hydrogenation method, which comprises an ethanol-cyclohexanol separation tower, a cyclohexanol lightness-removing tower, a dehydrogenation reactor, a cyclohexanone lightness-removing tower, a cyclohexanone tower, a cyclohexanol tower and a cyclohexyl acetate recovery tower which are connected in sequence, wherein an outlet at the top of the cyclohexanol lightness-removing tower is connected to the ethanol-cyclohexanol separation tower in a return mode; and the outlet at the top of the cyclohexanol tower is connected to the inlet of the dehydrogenation reactor.
Preferably, the top outlet of the cyclohexanol lightness-removing column is firstly connected to the reboiler of the cyclohexanone column kettle, and then is connected to the ethanol-cyclohexanol separation column in a returning manner.
Preferably, the outlet of the top of the cyclohexanol tower is firstly connected to the reboiler of the tower kettle of the cyclohexanone light component removal tower, and then is returned to be connected to the inlet of the dehydrogenation reactor.
Compared with the prior art, the invention has the following advantages:
1. the invention reduces the refining process of cyclohexanol, cancels a cyclohexanol deesterification tower, combines and separates light and heavy components generated by hydrogenation and dehydrogenation, and reduces equipment investment.
2. The cyclohexanol tower adopts positive pressure operation, so that the diameter of the cyclohexanol tower is reduced.
3. The invention realizes the cascade utilization of energy sources through multiple-effect thermal coupling and reduces the steam consumption.
Drawings
FIG. 1 is a process flow diagram of a prior art process for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation process;
FIG. 2 is a process flow diagram of a process for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation process according to the present invention;
FIG. 3 is a schematic diagram of the thermal coupling design of the process for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to the present invention;
wherein, 1, an ethanol-cyclohexanol separation column; 2. a cyclohexanol lightness-removing column; 3. a cyclohexanol deesterification column; 4. a cyclohexanol recovery column; 5. a dehydrogenation reactor; 6. a cyclohexanone lightness-removing tower; 7. a cyclohexanone tower; 8. a cyclohexanol column; 9. and a cyclohexyl acetate recovery tower.
Detailed Description
The technical solutions of the present invention will be described in detail below for the purpose of more clearly understanding the technical features, objects, and advantages of the present invention, but are not to be construed as limiting the implementable scope of the present invention.
As shown in fig. 1 and fig. 2:
in the prior art, after the cyclohexyl acetate is subjected to ester hydrogenation reaction, an ethanol-cyclohexanol mixture (containing a small amount of cyclohexyl acetate which cannot be completely reacted, a byproduct light component, a heavy component and the like) is generated, the ethanol-cyclohexanol mixture is subjected to an ethanol-cyclohexanol separation tower to obtain crude ethanol and crude cyclohexanol, the crude cyclohexanol is subjected to a cyclohexanol lightness-removing tower, the ethanol light component is removed from the top of the cyclohexanol lightness-removing tower, cyclohexanol is obtained from the bottom of the cyclohexanol lightness-removing tower, the cyclohexanol is subjected to a cyclohexanol deesterification tower (positive pressure operation) to remove the cyclohexyl acetate which is not completely reacted in the ester hydrogenation reaction, cyclohexanol at the top of the cyclohexanol deesterification tower is used as a feed of a dehydrogenation reactor, the cyclohexyl acetate-cyclohexanol mixture is obtained at the bottom of the cyclohexanol deesterification tower, the cyclohexyl acetate-cyclohexanol mixture is sent to a cyclohexanol recovery tower (positive pressure operation), and cyclohexanol at the top of the cyclohexanol recovery tower is returned to the cyclohexanol deesterification tower, and returning the cyclohexyl acetate at the tower bottom of the cyclohexanol recovery tower to the cyclohexyl acetate hydrogenation working section for refining and recycling.
The cyclohexanol tower is operated under negative pressure and the operation condition is the same as that of cyclohexane oxidation process. However, the crude cyclohexanol impurity species obtained by the esterification hydrogenation process are significantly different from those obtained by the oxidation process. Because the cyclohexane oxidation method cyclohexanone device produces a large amount of heavy X oil components, the melting boiling point of the mixture is high, the viscosity is high, the temperature of a tower kettle of a cyclohexanol tower of the cyclohexane oxidation method cyclohexanone device reaches 165-170 ℃ under the absolute pressure condition of 3KpaG, if negative pressure separation operation is adopted, the temperature of the tower kettle is higher, higher-grade superheated steam is needed as a heat source, alcohol ketone is a heat-sensitive substance, condensation of the alcohol ketone is aggravated at high temperature, and the material consumption is increased.
In the invention, the cyclohexanol tower is operated under positive pressure, and the ester content at the top of the tower can be controlled to be lower than 0.2 wt% by adjusting the reflux ratio, and the operation pressure is 5-30 KPa (shown in the table); the temperature of the top of the tower is 162-175 ℃, and the temperature of the bottom of the tower is 170-185 ℃.
A characteristic substance butyl cyclohexyl ether can be generated in a cyclohexane oxidation method cyclohexanone device dehydrogenation and alcohol ketone refining system, cannot be separated under the condition of an alcohol tower with 3KpaG absolute pressure, is accumulated in the dehydrogenation and alcohol ketone refining system along with cyclohexanol, and is stopped and ether is removed when 10% of cyclohexanol is accumulated generally, so that a certain flow of mixture (5-10% of feed) needs to be continuously pumped from a tower bottom of the alcohol tower, the mixture is sent into a small cyclohexanol ether removing tower, continuous ether removing operation is carried out under the positive pressure condition, cyclohexanol is obtained from the tower top, and an X oil heavy component enriched with butyl cyclohexyl ether is sent out as fuel oil from the tower bottom.
And the characteristic substances of ethyl cyclohexanol and ethyl cyclohexanone are generated in the device system for preparing cyclohexanone by the esterification hydrogenation method, and under the working conditions of positive pressure and negative pressure operation of the cyclohexanol tower, the ethyl cyclohexanol and the ethyl cyclohexanone are not discharged from the top of the cyclohexanol tower but are discharged from the bottom of the cyclohexanol tower, so that the problem that the characteristic substances are accumulated in the dehydrogenation and alcohol ketone refining system of the device for preparing cyclohexanone by the esterification method is solved.
In the invention, the cyclohexanol tower is operated at positive pressure, heavy components containing cyclohexyl acetate, cyclohexanol, ethyl cyclohexanol and ethyl cyclohexanone are obtained at the tower bottom, then the heavy components are sent to the cyclohexyl acetate recovery tower, the cyclohexanol and the cyclohexanol are recovered at the tower top under the negative pressure condition, the cyclohexanol and the cyclohexanol are returned to the cyclohexyl acetate hydrogenation section for refining and recycling, and the heavy components at the tower bottom are sent to a fuel oil system for sale.
Example 1
The flow of the test device is shown in figures 2 and 3, the inner diameter of the row tube of the cyclohexanol dehydrogenation reactor is 40mm, and the length of the row tube is 6000 mm; the specifications of the cyclohexanone light component removal tower, the cyclohexanone tower, the cyclohexanol tower and the cyclohexyl acetate recovery tower are shown in table 1, and the operation parameters are shown in table 2.
Mixing 27t/h of crude cyclohexanol and 25.6t/h of cyclohexanol recovered at the top of a cyclohexanol tower, feeding the mixture into a dehydrogenation reactor, carrying out dehydrogenation reaction at the temperature of 230 ℃ and under the pressure of 30KPa, feeding condensate into a cyclohexanone lightness-removing tower, and obtaining 200kg/h of light components at the top of the tower; and (3) feeding the tower bottom discharge into a cyclohexanone tower, obtaining 25t/h of cyclohexanone at the tower top, feeding the tower bottom discharge into a cyclohexanol tower, obtaining 25.6t/h of recycled cyclohexanol at the tower top, feeding the tower bottom discharge at 1.8t/h into a cyclohexyl acetate recovery tower, obtaining 1.53t/h of recycled cyclohexyl acetate at the tower top, wherein the content of cyclohexanol is 57%, feeding the cyclohexyl acetate to an ester hydrogenation working section, and feeding 270kg/h of heavy components at the tower bottom into a fuel oil system.
The device adopts superheated steam of 3.8MPa and 400 ℃ as a heat source, and superheated steam of 57t/h heats heat conduction oil to 300 ℃ and 4.0MPa, wherein 16t/h is sent to a reboiler of a cyclohexanol tower kettle, 9t/h is sent to a cyclohexanol vaporizer, 2t/h is sent to a reboiler of a cyclohexyl acetate recovery tower kettle, 26t/h can be sent to a benzene extraction tower reboiler, the top steam of the cyclohexanol tower is sent to the reboiler of a cyclohexanone lightness-removing tower kettle, and the top steam of the cyclohexanone lightness-removing tower is sent to the reboiler of the cyclohexanone tower kettle.
TABLE 1 Tower Specification parameters
TABLE 2 column operating parameters
Example 2
Before improvement, 1.0MPa steam is used as a heat source in a cyclohexanone lightness-removing tower and a cyclohexanone tower respectively, 4.0MPa steam is used as a heat source in a reboiler at a tower kettle of the cyclohexanol tower and a dehydrogenation evaporator (belonging to a dehydrogenation feeding system), steam is sent out by using steam condensate after being used, circulating heat conduction oil for the dehydrogenation reactor is heated by using a process heating furnace, and no thermal coupling design is carried out.
After improvement, the circulating heat-conducting oil is heated in a heat-conducting oil heater by utilizing the sensible heat of steam with the pressure of 3.8MPa and the temperature of 400 ℃, the sensible heat of the steam is changed into the steam with the pressure of 3.8MPa and the temperature of 300 ℃ after being utilized, and the steam can be continuously used as a heat source of a reboiler at the tower bottom of the cyclohexanol tower and a dehydrogenation evaporator (belonging to a dehydrogenation feeding system). The cyclohexanol tower is operated under positive pressure, the temperature at the top of the tower is 162-175 ℃, the temperature at the bottom of the cyclohexanone lightness-removing tower is 130-140 ℃, the temperature difference between the top of the cyclohexanol tower and the bottom of the cyclohexanone lightness-removing tower is proper, and the heat enthalpy of cyclohexanol is high, so that the cyclohexanol can be used as a reboiler heat source of the bottom of the cyclohexanone lightness-removing tower. The temperature of the top of the cyclohexanone light component removal tower is 110-135 ℃, the temperature of the top of the cyclohexanone light component removal tower is 50-60 ℃, the temperature of the tower kettle is 80-10 ℃, the temperature difference between the top of the cyclohexanone light component removal tower and the tower kettle of the cyclohexanone light component removal tower is proper, and the cyclohexanone light component removal tower can be used as a reboiler heat source of the tower kettle of the cyclohexanone light component removal tower because the content of cyclohexanone reaches 80% and the enthalpy of the cyclohexanone light component removal tower is also high.
The invention can also adopt a second thermal coupling utilization scheme, namely, the top steam of the cyclohexanol tower is used for preheating the feeding material of the cyclohexanone lightness-removing tower, and the top steam of the cyclohexanone lightness-removing tower is used for preheating the feeding material of the cyclohexanone tower, so that the energy-saving effect can be obtained.
Performing heat integration simulation calculation on a 200kt/a cyclohexanol device by adopting ASPEN, calculating dehydrogenation reaction according to 50% conversion rate, wherein the heat load of a heat conduction oil heater is 4000kw, steam enters at the temperature of 400 ℃ under the pressure of 3.8MPa, steam exits at the temperature of 300 ℃ under the pressure of 3.8MPa, 57t/h of steam is needed, and the residual enthalpy is 44333 kw; feeding the cyclohexanone into a reboiler of a lightness-removing column for heat load of 16300kw, and feeding a condenser at the top of the tower for heat load of 15800 kw; the heat load of a reboiler of the cyclohexyl acetate recovery tower is 15039kw, and the heat load of a condenser at the top of the tower is 16300 kw; the heat load of a reboiler of a cyclohexanone tower is 13449kw, and the heat load of a condenser at the top of the cyclohexanone tower is 15855 kw; the heat load of the reboiler of the cyclohexanol tower is 12498kw, and the heat load of the condenser at the top of the tower is 14060 kw; the single tower is adopted for direct steam heating, the total heat load of the four towers is 57286kw, the steam is saved by 57.6t/h in total, the cyclohexanol deesterification tower is omitted, the steam is saved by 19.33t/h, and the equipment investment is saved by 300 ten thousand yuan.
Claims (10)
1. A method for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation method is characterized by comprising the following steps: sending an ethanol-cyclohexanol mixture obtained by hydrogenating cyclohexyl acetate into an ethanol-cyclohexanol separation tower for rectification separation, extracting distillate of the ethanol-cyclohexanol separation tower, sending tower bottom liquid of the ethanol-cyclohexanol separation tower into a cyclohexanol lightness-removing tower for rectification separation, returning the distillate of the cyclohexanol lightness-removing tower into the ethanol-cyclohexanol separation tower, sending the tower bottom liquid of the cyclohexanol lightness-removing tower into a dehydrogenation reactor for reaction, sequentially passing materials after dehydrogenation reaction through the cyclohexanone lightness-removing tower, the cyclohexanone tower and the cyclohexanol tower, sending the materials into a cyclohexyl acetate recovery tower for rectification separation, returning the distillate of the cyclohexyl acetate recovery tower to a cyclohexyl acetate hydrogenation working section, and extracting the tower bottom liquid of the cyclohexyl acetate recovery tower for sale as fuel oil.
2. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 1, wherein: with outer tube superheated steam as a heat source, firstly sending the heat-conducting oil to a heat-conducting oil heat exchanger to exchange heat with heat-conducting oil of dehydrogenation reaction, then sending part of the heat-conducting oil to a reboiler at the bottom of the cyclohexanol tower to supply heat, sending part of the heat-conducting oil to the reboiler at the bottom of the cyclohexyl acetate recovery tower to supply heat, and sending the rest of the heat-conducting oil to other working procedures; firstly, sending the distillate of the cyclohexanone lightness-removing tower to a reboiler at the bottom of the cyclohexanone tower for heat exchange and then extracting; the distillate of the cyclohexanol tower is sent to a reboiler at the bottom of a cyclohexanone lightness-removing tower for heat exchange and then sent to a dehydrogenation reactor.
3. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 2, wherein: the pressure of the superheated steam is 3.5-4.5 MPa, the temperature is 390-430 ℃, the pressure after heat exchange with the heat conduction oil is 3.5-4.5 MPa, and the temperature is 250-300 ℃.
4. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 1, wherein: the dehydrogenation reactor is a tubular reactor, the inner diameter of the tubular reactor is 30-50 mm, the length of the tubular reactor is 5000-8000 mm, the shell pass of heat conducting oil is taken, the tube pass of cyclohexanol is taken, the pressure difference of the tubular reactor is 5-30 KPa, the reaction temperature is 220-260 ℃, and the pressure is 5-30 KPa (shown in the table).
5. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 1, wherein: the cyclohexanone lightness-removing tower is a packed tower, the number of tower plates is 15-40, the operation pressure is 20-50 KPa (absolute), the reflux ratio is 350-450, the temperature at the top of the tower is 110-135 ℃, and the temperature at the bottom of the tower is 130-140 ℃.
6. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 1, wherein: the cyclohexanone tower is a packed tower, the number of tower plates is 60-80, and the operating pressure is 2-5 KPa (absolute); the reflux ratio is 2-4, the temperature at the top of the tower is 50-60 ℃, and the temperature at the bottom of the tower is 80-100 ℃.
7. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 1, wherein: the cyclohexanol tower is a packed tower, the number of tower plates is 40-60, the reflux ratio is 1-3, and the operating pressure is 5-30 KPa (shown in the table); the temperature of the top of the tower is 162-175 ℃, and the temperature of the bottom of the tower is 170-185 ℃.
8. The method for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 1, wherein: the cyclohexyl acetate recovery tower is a packed tower, the number of tower plates is 20-40, the reflux ratio is 1-3, the operating pressure is 5-30 KPa (absolute), the temperature of the top of the tower is 100-130 ℃, and the temperature of a tower kettle is 150-180 ℃.
9. A device for preparing cyclohexanone from crude cyclohexanol obtained by an esterification hydrogenation method is characterized in that: the device comprises an ethanol-cyclohexanol separation tower, a cyclohexanol lightness-removing tower, a dehydrogenation reactor, a cyclohexanone lightness-removing tower, a cyclohexanone tower, a cyclohexanol tower and a cyclohexyl acetate recovery tower which are connected in sequence, wherein an outlet at the top of the cyclohexanol lightness-removing tower is connected to the ethanol-cyclohexanol separation tower in a return mode; and the outlet at the top of the cyclohexanol tower is connected to the inlet of the dehydrogenation reactor.
10. The apparatus for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation according to claim 9, wherein: the top outlet of the cyclohexanol lightness-removing tower is firstly connected to a reboiler of a cyclohexanone tower kettle and then is connected to the ethanol-cyclohexanol separation tower in a returning way;
and the outlet at the top of the cyclohexanol tower is firstly connected to a reboiler at the bottom of the cyclohexanone lightness-removing tower and then returns to be connected to the inlet of the dehydrogenation reactor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110041480.6A CN114763318B (en) | 2021-01-13 | 2021-01-13 | Method and device for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110041480.6A CN114763318B (en) | 2021-01-13 | 2021-01-13 | Method and device for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114763318A true CN114763318A (en) | 2022-07-19 |
| CN114763318B CN114763318B (en) | 2023-12-29 |
Family
ID=82363095
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110041480.6A Active CN114763318B (en) | 2021-01-13 | 2021-01-13 | Method and device for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114763318B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105237370A (en) * | 2015-10-15 | 2016-01-13 | 李国涛 | Method for producing cyclohexanone by cyclohexanol dehydrogenation |
| CN205152115U (en) * | 2015-10-15 | 2016-04-13 | 湖南百利工程科技股份有限公司 | Cyclohexanone and cyclohexanol separation economizer in cyclohexene method cyclohexanone production process |
| CN205152116U (en) * | 2015-10-15 | 2016-04-13 | 湖南百利工程科技股份有限公司 | Cyclohexanone and cyclohexanol separation economizer in cyclohexanone production process |
| CN106083544A (en) * | 2016-06-02 | 2016-11-09 | 中国化学赛鼎宁波工程有限公司 | Cyclohexanone is refined and cyclohexanol recoverying and utilizing method and system |
| CN106518640A (en) * | 2016-10-21 | 2017-03-22 | 中国天辰工程有限公司 | High efficiency separation and refinement method of cyclohexanone product |
| CN108003017A (en) * | 2016-10-28 | 2018-05-08 | 中国石油化工股份有限公司 | The production method and cyclohexanol production device of the separation method of cyclohexyl acetate and the production method of cyclohexyl acetate and cyclohexanol |
| CN212102639U (en) * | 2020-03-24 | 2020-12-08 | 浙江恒澜科技有限公司 | Device for refining cyclohexanone by cyclohexanol dehydrogenation |
| CN112745208A (en) * | 2019-10-30 | 2021-05-04 | 中国石油化工股份有限公司 | Cyclohexanone recovery and separation process and system |
-
2021
- 2021-01-13 CN CN202110041480.6A patent/CN114763318B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105237370A (en) * | 2015-10-15 | 2016-01-13 | 李国涛 | Method for producing cyclohexanone by cyclohexanol dehydrogenation |
| CN205152115U (en) * | 2015-10-15 | 2016-04-13 | 湖南百利工程科技股份有限公司 | Cyclohexanone and cyclohexanol separation economizer in cyclohexene method cyclohexanone production process |
| CN205152116U (en) * | 2015-10-15 | 2016-04-13 | 湖南百利工程科技股份有限公司 | Cyclohexanone and cyclohexanol separation economizer in cyclohexanone production process |
| CN106083544A (en) * | 2016-06-02 | 2016-11-09 | 中国化学赛鼎宁波工程有限公司 | Cyclohexanone is refined and cyclohexanol recoverying and utilizing method and system |
| CN106518640A (en) * | 2016-10-21 | 2017-03-22 | 中国天辰工程有限公司 | High efficiency separation and refinement method of cyclohexanone product |
| CN108003017A (en) * | 2016-10-28 | 2018-05-08 | 中国石油化工股份有限公司 | The production method and cyclohexanol production device of the separation method of cyclohexyl acetate and the production method of cyclohexyl acetate and cyclohexanol |
| CN112745208A (en) * | 2019-10-30 | 2021-05-04 | 中国石油化工股份有限公司 | Cyclohexanone recovery and separation process and system |
| CN212102639U (en) * | 2020-03-24 | 2020-12-08 | 浙江恒澜科技有限公司 | Device for refining cyclohexanone by cyclohexanol dehydrogenation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114763318B (en) | 2023-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101703840B (en) | Four-effect rectification system for synthesizing leather dimethyl formamide solution by wet method and recovery method | |
| CN107628930A (en) | A kind of heat pump separation of extractive distillation methanol, the energy saving technique of isopropyl alcohol and water | |
| CN112811984B (en) | Baffle rectification process and equipment for propynylol and butynyldiol aqueous solution system | |
| CN111233690A (en) | DMAc thermal coupling refining and recycling system and method | |
| CN109748791B (en) | Energy-saving method for producing dimethyl adipate | |
| CN212102639U (en) | Device for refining cyclohexanone by cyclohexanol dehydrogenation | |
| CN111333484A (en) | Ultrahigh-purity methane chloride production system and process | |
| CN114763318B (en) | Method and device for preparing cyclohexanone from crude cyclohexanol obtained by esterification hydrogenation method | |
| CN214781576U (en) | Caprolactam rearrangement heat energy cyclic utilization device | |
| CN112479869B (en) | Method for rectifying dimethyl oxalate in coal chemical industry | |
| CN113121314A (en) | Device and method for recycling tertiary butanol by using dividing wall rectifying tower and combining heat pump technology | |
| CN112898148A (en) | Process and apparatus for refining glyoxylic acid | |
| CN215975598U (en) | Device for refining cyclohexanone by cyclohexanol dehydrogenation | |
| CN212425916U (en) | Ultra-high-purity methane chloride production system | |
| CN107434757B (en) | Method and device for recycling caprolactam organic extractant with ultralow energy consumption | |
| CN217041342U (en) | Device for reducing steam consumption in caprolactam refining process production | |
| CN218146433U (en) | Energy-saving process device for acrylic acid refining process | |
| CN109852413A (en) | A kind of method of coal tar production modified coal tar pitch | |
| CN114681942B (en) | Complete pressure swing coupling rectification device and rectification method for tertiary butanol recovery | |
| CN215799238U (en) | Process unit for refining glyoxylic acid | |
| CN215712710U (en) | Device for recovering tert-butanol by using dividing wall rectifying tower combined with open or closed heat pump | |
| CN215975597U (en) | Energy-saving recovery device for ammoximation reaction solvent tert-butyl alcohol by using open or closed heat pump | |
| CN115364504B (en) | System and method for separating acetaldehyde from diethyl ether | |
| CN113680088B (en) | Multi-effect rectifying method, rectifying device and application thereof | |
| CN116726525A (en) | Efficient energy-saving rectification system and process for preparing cyclohexanone by hydration method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |