CN113292408A - Process for producing o-chlorobenzaldehyde by chlorination distillation method - Google Patents
Process for producing o-chlorobenzaldehyde by chlorination distillation method Download PDFInfo
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- 238000005660 chlorination reaction Methods 0.000 title claims abstract description 116
- 238000000034 method Methods 0.000 title claims abstract description 48
- FPYUJUBAXZAQNL-UHFFFAOYSA-N 2-chlorobenzaldehyde Chemical compound ClC1=CC=CC=C1C=O FPYUJUBAXZAQNL-UHFFFAOYSA-N 0.000 title claims abstract description 45
- 238000004821 distillation Methods 0.000 title claims abstract description 10
- 239000007788 liquid Substances 0.000 claims abstract description 65
- 238000006460 hydrolysis reaction Methods 0.000 claims abstract description 39
- 230000007062 hydrolysis Effects 0.000 claims abstract description 34
- 239000003513 alkali Substances 0.000 claims abstract description 24
- 238000005904 alkaline hydrolysis reaction Methods 0.000 claims abstract description 21
- 239000000460 chlorine Substances 0.000 claims abstract description 21
- BASMANVIUSSIIM-UHFFFAOYSA-N 1-chloro-2-(chloromethyl)benzene Chemical compound ClCC1=CC=CC=C1Cl BASMANVIUSSIIM-UHFFFAOYSA-N 0.000 claims abstract description 18
- IBSQPLPBRSHTTG-UHFFFAOYSA-N 1-chloro-2-methylbenzene Chemical compound CC1=CC=CC=C1Cl IBSQPLPBRSHTTG-UHFFFAOYSA-N 0.000 claims abstract description 18
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052801 chlorine Inorganic materials 0.000 claims abstract description 16
- 238000004519 manufacturing process Methods 0.000 claims abstract description 16
- 239000003054 catalyst Substances 0.000 claims abstract description 11
- 238000005406 washing Methods 0.000 claims abstract description 9
- 238000007670 refining Methods 0.000 claims abstract description 8
- 239000002994 raw material Substances 0.000 claims abstract description 7
- 125000006286 dichlorobenzyl group Chemical group 0.000 claims description 55
- 239000012043 crude product Substances 0.000 claims description 38
- 238000010438 heat treatment Methods 0.000 claims description 32
- 150000001299 aldehydes Chemical class 0.000 claims description 28
- 239000000047 product Substances 0.000 claims description 28
- KCXMKQUNVWSEMD-UHFFFAOYSA-N benzyl chloride Chemical compound ClCC1=CC=CC=C1 KCXMKQUNVWSEMD-UHFFFAOYSA-N 0.000 claims description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 25
- 238000005086 pumping Methods 0.000 claims description 24
- 238000003860 storage Methods 0.000 claims description 24
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 20
- 238000004064 recycling Methods 0.000 claims description 19
- 239000000498 cooling water Substances 0.000 claims description 18
- 238000003756 stirring Methods 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 15
- JQZAEUFPPSRDOP-UHFFFAOYSA-N 1-chloro-4-(chloromethyl)benzene Chemical compound ClCC1=CC=C(Cl)C=C1 JQZAEUFPPSRDOP-UHFFFAOYSA-N 0.000 claims description 13
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 12
- 238000001816 cooling Methods 0.000 claims description 12
- 238000004806 packaging method and process Methods 0.000 claims description 12
- CAHQGWAXKLQREW-UHFFFAOYSA-N Benzal chloride Chemical compound ClC(Cl)C1=CC=CC=C1 CAHQGWAXKLQREW-UHFFFAOYSA-N 0.000 claims description 11
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 claims description 10
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 claims description 10
- 229940073608 benzyl chloride Drugs 0.000 claims description 10
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims description 8
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims description 8
- 239000003999 initiator Substances 0.000 claims description 8
- -1 monochlorobenzyl Chemical group 0.000 claims description 7
- 125000003963 dichloro group Chemical group Cl* 0.000 claims description 6
- 238000004508 fractional distillation Methods 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 6
- 230000005484 gravity Effects 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 6
- 238000011084 recovery Methods 0.000 claims description 6
- 239000011787 zinc oxide Substances 0.000 claims description 6
- 238000005194 fractionation Methods 0.000 claims description 5
- 238000000746 purification Methods 0.000 claims description 4
- 238000006386 neutralization reaction Methods 0.000 claims description 3
- 239000003518 caustics Substances 0.000 claims description 2
- 125000004803 chlorobenzyl group Chemical group 0.000 claims description 2
- 239000010802 sludge Substances 0.000 claims description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 claims 1
- BXSVYGKOUULJCL-UHFFFAOYSA-N 1-chloro-2-(dichloromethyl)benzene Chemical compound ClC(Cl)C1=CC=CC=C1Cl BXSVYGKOUULJCL-UHFFFAOYSA-N 0.000 abstract description 7
- 238000003912 environmental pollution Methods 0.000 abstract description 6
- 239000002699 waste material Substances 0.000 abstract description 4
- 230000035484 reaction time Effects 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract description 3
- 238000006555 catalytic reaction Methods 0.000 abstract description 2
- 230000007547 defect Effects 0.000 abstract description 2
- 230000000694 effects Effects 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 abstract description 2
- 239000000463 material Substances 0.000 abstract description 2
- 238000006116 polymerization reaction Methods 0.000 abstract description 2
- 231100000331 toxic Toxicity 0.000 abstract description 2
- 230000002588 toxic effect Effects 0.000 abstract description 2
- 238000007086 side reaction Methods 0.000 description 4
- MROCJMGDEKINLD-UHFFFAOYSA-N dichlorosilane Chemical compound Cl[SiH2]Cl MROCJMGDEKINLD-UHFFFAOYSA-N 0.000 description 3
- 238000009826 distribution Methods 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- AIPJZPPOFWCJRC-UHFFFAOYSA-N 1,2-dichloro-3-(chloromethyl)benzene Chemical compound ClCC1=CC=CC(Cl)=C1Cl AIPJZPPOFWCJRC-UHFFFAOYSA-N 0.000 description 1
- 206010024769 Local reaction Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000013064 chemical raw material Substances 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 125000001309 chloro group Chemical group Cl* 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
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- 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
- C07C45/42—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by hydrolysis
- C07C45/43—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by hydrolysis of >CX2 groups, X being halogen
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
- C07C17/10—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms
- C07C17/14—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms in the side-chain of aromatic compounds
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- 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
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
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- 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
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C45/82—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
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Abstract
The invention provides a new process for producing o-chlorobenzaldehyde by a chlorination distillation method, which takes o-chlorotoluene and chlorine as raw materials, and adopts a tower type chlorination catalytic reaction distillation technology to synthesize o-chlorobenzyl chloride and o-chlorobenzylidene dichloride, wherein the chlorinated solution is subjected to alkali washing and reduced pressure distillation to prepare the o-chlorobenzyl chloride with the content of more than 99.0 percent, and the o-chlorobenzylidene dichloride is subjected to hydrolysis, alkaline hydrolysis and refining to prepare the high-purity o-chlorobenzaldehyde; the method overcomes the defects of insufficient activity of a catalyst adopted in the hydrolysis reaction, long hydrolysis reaction time, serious material polymerization, large amount of residual liquid, low hydrolysis yield, direct discharge of waste liquid containing a large amount of toxic and harmful substances and serious environmental pollution in the current production process. The yield of the chlorination reaction can reach more than 98.0 percent, the total yield of the o-chlorobenzyl chloride product is more than 92 percent, the total yield of the o-chlorobenzaldehyde product is more than 92 percent, and the utilization rate of chlorine can reach more than 90.0 percent. Compared with the domestic same industry, the method has the characteristics of high product yield, good quality, small environmental pollution and the like.
Description
Technical Field
The invention relates to the technical field of production of o-chlorobenzaldehyde, in particular to a process for producing o-chlorobenzaldehyde by a chlorination distillation method.
Background
O-chlorobenzaldehyde is an important chemical raw material, is a colorless transparent liquid and is mainly used in organic synthesis, pesticide, pharmacy and dye industry. At present, the main production process at home and abroad is a chlorination hydrolysis process, and the production process takes o-chlorotoluene and chlorine as raw materials, synthesizes o-chlorobenzylidene dichloride through catalytic chlorination, prepares an o-chlorobenzylidene dichloride crude product through reduced pressure rectification, and prepares an o-chlorobenzaldehyde finished product through hydrolysis reaction, wherein the total yield is about 82%.
The chlorination synthesis reaction of the method is generally adopted in actual industrial production at present as a kettle type chlorination process, the reaction temperature is between 130 ℃ and 150 ℃, the local reaction is serious due to high reaction temperature and uneven distribution of chlorine, the occurrence of side reaction can not be strictly controlled, the content of polychloride in reaction products is high, the chlorination reaction yield is low and is only about 92 percent, and the utilization rate of chlorine is only about 80 percent; meanwhile, the catalyst used in the hydrolysis reaction has insufficient activity, the hydrolysis reaction time is long, the polymerization of materials is serious, and the amount of residual liquid is large, so that the hydrolysis yield is low and is only about 90%, and the purity of the finally obtained o-chlorobenzaldehyde is only about 95%. The problems not only cause lower overall yield, waste of raw materials and increased cost, but also cause direct discharge of waste liquid containing a large amount of toxic and harmful substances and serious environmental pollution. Therefore, a better o-chlorobenzaldehyde production process is needed.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a process for producing o-chlorobenzaldehyde by a chlorination distillation method, which solves the problems of low overall yield, raw material waste, cost increase and serious environmental pollution in the prior art.
According to the embodiment of the invention, the process for producing o-chlorobenzaldehyde by chlorination and rectification selects o-chlorotoluene and chlorine as raw materials, and the production process comprises the following steps:
(1) chlorination: measuring o-chlorotoluene by a feed pump, then feeding the o-chlorotoluene into a chlorination reaction tower, adding an initiator, starting a light source, opening a condenser cooling water on the top of the tower, heating the tower to 100 ℃, feeding chlorine gas in a sectional measurement manner, controlling the reaction temperature to be at 120-130 ℃, stopping feeding the chlorine gas when the specific gravity of a chlorination solution reaches 1.34 under the condition of 20 ℃, putting the chlorination solution into an alkaline tank, quantitatively adding alkali for neutralization, stirring for 2 hours, measuring the pH value of the chlorination solution, stopping stirring when the pH value of the chlorination solution is 6-7, standing for layering, and then putting the chlorination solution into a chlorination solution storage tank;
(2) fractional distillation: firstly, pumping a chlorination solution from a chlorination solution storage tank to a tower I kettle, heating to 150 ℃, opening a condenser cooling water at the top of the tower, separating chlorotoluene and monochlorobenzyl by reduced pressure fractionation, purifying a crude dichlorobenzyl product in the tower kettle, controlling the monochlorobenzyl to be less than or equal to 10.0%, and putting the purified dichlorobenzyl product into a tower I kettle liquid tank to serve as a feed of a tower II;
(3) and (3) rectification: pumping the purified crude product of dichlorobenzyl from a liquid tank of a tower I to a feeding head tank of a tower II, feeding the crude product of dichlorobenzyl into the tower II through a rotameter, heating to raise the temperature to 140 ℃ and open a condenser at the top of the tower for cooling water, separating the o-chlorobenzyl chloride and the residual monochlorobenzyl chloride in the crude product of dichlorobenzyl in the tower kettle through reduced pressure rectification, and when the content of monochlorobenzyl chloride in the dichlorobenzyl in the tower kettle is less than or equal to 0.2%, putting the crude product of dichlorobenzyl in the tower kettle to the liquid tank of the tower II for the next process;
(4) hydrolysis and alkaline hydrolysis: pumping purified benzyl dichloride from a liquid tank of a tower II to a dichloro head tank, then putting the dichloro head tank into a hydrolysis kettle, then adding a catalyst, starting stirring, opening cooling water of a condenser, heating to 120-130 ℃, then opening an outlet valve of the water head tank, continuously measuring and dripping water, stopping hydrolysis when the content of benzyl dichloride is less than or equal to 0.1%, cooling to 80 ℃, quantitatively adding 30% pure alkali liquor from the alkali liquor head tank for alkaline hydrolysis for 2-3 hours, stopping alkaline hydrolysis when the content of benzyl monochloride is less than or equal to 0.2%, cooling, washing and layering to obtain a crude aldehyde liquid, and putting the crude aldehyde liquid into a crude aldehyde tank;
(5) refining: and (3) pumping the hydrolyzed crude aldehyde liquid to a tower III kettle, heating to 120-130 ℃, opening a tower top condenser to cool water, performing reduced pressure rectification, wherein the front fraction liquid enters a tower top front fraction groove through the tower top condenser and is returned to the hydrolysis kettle for recycling, and the o-chlorobenzaldehyde is purified and then enters a tower top liquid groove III from the tower top condenser and is put into an o-chlorobenzaldehyde finished product groove for packaging.
Further, in the chlorination step, hydrogen chloride gas generated in the chlorination reaction is recycled by a tower top condenser and enters a hydrochloric acid recycling system.
Further, in the fractionation step, the chlorotoluene is subjected to reduced pressure fractionation and purification, then is discharged from a front fraction tank at the top of the tower to a chlorotoluene recovery storage tank, and is recycled in the chlorination tower, and the benzyl chloride at the top of the tower is subjected to reduced pressure fractionation and purification, and then is discharged from a liquid tank at the top of the tower I to a benzyl chloride finished product tank for packaging.
Further, in the rectification step, after the o-chlorobenzyl chloride in the crude dichlorobenzyl in the tower kettle is recovered and purified through reduced pressure rectification, the o-chlorobenzyl chloride enters a liquid tank at the top of the tower II from a condenser at the top of the tower, and then the o-chlorobenzyl chloride is placed in a chlorination liquid storage tank for recycling.
Preferably, the chlorination reaction tower, the tower I, the tower II and the tower III are provided with steam pipelines, and steam is adopted for heating and warming.
Preferably, the alkali added in the chlorination step is 10% industrial liquid alkali or 10% industrial caustic sludge.
Preferably, in the chlorination step, the initiator is 0.1% azobisisobutyronitrile.
Preferably, in the hydrolysis and alkaline hydrolysis steps, the catalyst is 0.2% active zinc oxide.
The technical principle of the invention is as follows: the method comprises the following steps of (1) synthesizing o-chlorobenzyl chloride and o-chlorobenzylidene dichloride by taking o-chlorotoluene and chlorine as raw materials and adopting an advanced tower type chlorination catalytic reaction rectification technology, carrying out alkali washing and reduced pressure rectification on a chlorination solution to obtain the o-chlorobenzyl chloride with the content of more than 99.0%, and carrying out hydrolysis, alkali hydrolysis and refining on the o-chlorobenzylidene dichloride to obtain the o-chlorobenzaldehyde;
reaction principle chemical equation:
C7H7Cl+Cl2＝C7H6Cl2+HCl；
C7H6Cl2+Cl2＝C7H5Cl3+HCl；
C7H5Cl3+H2O＝C7H5ClO+2HCl。
compared with the prior art, the invention has the following beneficial effects:
1. because the reaction temperature directly influences the substitution selectivity of chlorine atoms on benzene rings in the chlorination reaction, the side reaction probability is increased when the reaction temperature is higher, so that the selectivity of o-chlorobenzylidene dichloride in the chlorination reaction is reduced, and the yield is reduced; therefore, the invention properly reduces the reaction temperature which is 120-130 ℃, effectively controls the occurrence of side reaction and improves the yield of chlorination reaction under the condition of ensuring certain reaction efficiency;
2. the invention adopts the tower type chlorination process, greatly improves the distribution condition of chlorine during the reaction, avoids the reaction liquid from forming vortex, ensures that the o-chlorotoluene is fully contacted with the chlorine, shortens the reaction time and improves the utilization rate of the chlorine;
3. the invention adopts the rectification method production process, can produce two products of o-chlorobenzyl chloride and o-chlorobenzaldehyde at the same time, compared with the traditional deep chlorination process, the rectification method production process effectively recovers the o-chlorobenzyl chloride, greatly improves the product yield, and improves by 10%;
4. the method improves the traditional hydrolysis process, adopts active high-efficiency catalyst active zinc oxide, and adopts a continuous dropwise adding mode, so that the added water is ensured not to be excessive all the time, and side reactions are avoided, thereby greatly improving the hydrolysis yield which is over 95.0 percent and reducing the environmental pollution;
5. the chlorination reaction yield can reach more than 98.0 percent, the primary conversion rate is more than 95.0 percent, the total yield of the o-chlorobenzyl chloride product is more than 92 percent, the total yield of the o-chlorobenzaldehyde product is more than 92 percent, and the utilization rate of chlorine can reach more than 90.0 percent; the method has the characteristics of high product yield, good quality, small environmental pollution and the like, and meanwhile, the method has strong reproducibility of the whole process, simple and easily-obtained equipment and industrial production conditions.
Drawings
FIG. 1 is a schematic process flow diagram of the present invention.
Detailed Description
The technical solution of the present invention is further described with reference to fig. 1 and the embodiments.
Example 1:
the production process of the embodiment is as follows:
1. chlorination of
Measuring o-chlorotoluene by a feed pump, then feeding the o-chlorotoluene into a chlorination reaction tower, adding 0.1% azobisisobutyronitrile as an initiator, starting a light source, opening a condenser cooling water at the top of the tower, heating to 100 ℃, introducing chlorine gas in a sectional measurement manner, controlling the reaction temperature to be 120 ℃, stopping introducing chlorine when the specific gravity of a chlorination solution reaches 1.34 under the condition of 20 ℃, putting the chlorination solution into an alkaline tank, quantitatively adding 10% of industrial alkaline residue, starting stirring for 2 hours, measuring the pH value of the chlorination solution, stopping stirring when the pH value of the chlorination solution is 6, standing for layering, and then putting the chlorination solution into a chlorination solution storage tank; and hydrogen chloride gas generated in the chlorination reaction is recycled by the tower top condenser and enters a hydrochloric acid recycling system.
2. Fractional distillation
Firstly, pumping a chlorination solution from a chlorination solution storage tank to a tower I, opening a steam inlet valve, heating to 140 ℃, opening a tower top condenser for cooling water, wherein chlorotoluene is purified by reduced pressure distillation (the content is more than or equal to 80.0%) and then is discharged from a tower top front fraction tank to a chlorotoluene recovery storage tank, and then is recycled in a chlorination tower, after the chlorobenzyl chloride is purified by reduced pressure distillation at the tower top (the content is more than or equal to 99.0%), the monochlorobenzyl chloride is discharged from a tower top liquid tank to a chlorobenzyl finished product tank for packaging, and after the dichlorobenzyl crude product at the tower bottom is purified (the monochlorobenzyl chloride is controlled to be less than or equal to 10.0%), the dichlorobenzyl crude product is discharged to a tower bottom liquid tank at the tower I to be used as a feed for a tower II.
3. Rectification
Pumping the purified crude product of the dichlorobenzyl from a tank of a tower I to a feeding head tank of a tower II, feeding the crude product of the dichlorobenzyl into a tower II through a rotameter, opening a steam inlet valve, heating to 140 ℃, opening a condenser at the top of the tower to cool water, recovering and purifying the ortho-chlorobenzyl chloride in the crude product of the dichlorobenzyl in the tower through reduced pressure rectification, feeding the crude product of the dichlorobenzyl into a tank of the tower II from the condenser at the top of the tower, and then putting the crude product of the dichlorobenzyl into a chlorination liquid storage tank for recycling, wherein when the content of the monochlorobenzyl chloride in the dichlorobenzyl in the tower kettle is less than or equal to 0.2%, the crude product of the dichlorobenzyl in the tower is put into the tank of the tower II for the next process.
4. Hydrolysis, alkaline hydrolysis
Pumping purified dichlorobenzyl from a liquid tank of a tower II to a dichlorosilane head tank, then putting the dichlorobenzyl into a hydrolysis kettle, adding 0.2% of catalyst namely active zinc oxide, starting stirring, opening condenser cooling water, heating to 125 ℃, then opening an outlet valve of the water head tank, continuously metering and dripping water, stopping hydrolysis when the content of dichlorobenzyl is less than or equal to 0.1%, cooling to 80 ℃, quantitatively adding 30% pure alkali liquor from the alkali liquor head tank for alkaline hydrolysis for 2-3 hours, stopping alkaline hydrolysis when the content of monochlorobenzyl is less than or equal to 0.2%, and cooling, washing and layering to obtain crude aldehyde liquid, and putting the crude aldehyde liquid into a crude aldehyde tank for use in a refined aldehyde post of the next procedure.
5. Refining
And (3) pumping the hydrolyzed crude aldehyde liquid to a tower III kettle, opening a steam inlet valve, heating to 120 ℃, opening a tower top condenser to cool water, performing reduced pressure rectification, wherein the front distillate enters a tower top front distillate groove through the tower top condenser and is returned to the hydrolysis kettle for recycling, and the o-chlorobenzaldehyde is purified and then enters a tower top liquid tank III from the tower top condenser and is put into an o-chlorobenzaldehyde finished product groove for packaging.
The purity of the o-chlorobenzaldehyde product obtained in the embodiment is 99.5%, and the total yield of the o-chlorobenzaldehyde product is 93%.
Example 2:
the production process of the embodiment is as follows:
1. chlorination of
Measuring o-chlorotoluene by a feed pump, then feeding the o-chlorotoluene into a chlorination reaction tower, adding 0.1% azobisisobutyronitrile as an initiator, starting a light source, opening a condenser cooling water at the top of the tower, heating to 100 ℃, introducing chlorine gas in a sectional measurement manner, controlling the reaction temperature to be 125 ℃, stopping introducing chlorine when the specific gravity of a chlorination solution reaches 1.34 under the condition of 20 ℃, putting the chlorination solution into an alkaline tank, quantitatively adding 10% industrial liquid alkali, starting stirring for 2 hours, measuring the pH value of the chlorination solution, stopping stirring when the pH value of the chlorination solution is 6.5, standing for layering, and then putting the chlorination solution into a chlorination solution storage tank; and hydrogen chloride gas generated in the chlorination reaction is recycled by the tower top condenser and enters a hydrochloric acid recycling system.
2. Fractional distillation
Firstly, pumping a chlorination solution from a chlorination solution storage tank to a tower I, opening a steam inlet valve, heating to 145 ℃, opening a tower top condenser for cooling water, wherein chlorotoluene is purified by reduced pressure rectification (the content is more than or equal to 80.0%) and then is discharged from a tower top front cut tank to a chlorotoluene recovery storage tank, and then is recycled in a chlorination tower, after benzyl chloride at the tower top is purified by reduced pressure rectification (the content is more than or equal to 99.0%), the benzyl chloride at the tower top is discharged from a tower top liquid tank to a benzyl chloride finished product tank for packaging, a crude benzyl dichloride at the tower bottom is purified, the content of benzyl chloride is controlled to be less than or equal to 10.0%, and the purified benzyl chloride is discharged to a tower bottom liquid tank of the tower I to be used as a feed of a tower II.
3. Rectification
Pumping the purified crude product of the dichlorobenzyl from a tank of a tower I to a feeding head tank of a tower II, feeding the crude product of the dichlorobenzyl into a tower II through a rotameter, opening a steam inlet valve, heating to 145 ℃, opening a condenser at the top of the tower to cool water, recovering and purifying the ortho-chlorobenzyl chloride in the crude product of the dichlorobenzyl in the tower through reduced pressure rectification, feeding the crude product of the dichlorobenzyl into a tank of the tower II from the condenser at the top of the tower, and then putting the crude product of the dichlorobenzyl into a chlorination liquid storage tank for recycling, wherein when the content of the monochlorobenzyl chloride in the dichlorobenzyl in the tower kettle is less than or equal to 0.2%, the crude product of the dichlorobenzyl in the tower is put into the tank of the tower II for the next process.
4. Hydrolysis, alkaline hydrolysis
Pumping purified dichlorobenzyl from a liquid tank of a tower II to a dichlorosilane head tank, then putting the dichlorobenzyl into a hydrolysis kettle, adding 0.2% of catalyst namely active zinc oxide, starting stirring, opening condenser cooling water, heating to 125 ℃, then opening an outlet valve of the water head tank, continuously metering and dripping water, stopping hydrolysis when the content of dichlorobenzyl is less than or equal to 0.1%, cooling to 80 ℃, quantitatively adding 30% pure alkali liquor from the alkali liquor head tank for alkaline hydrolysis for 2-3 hours, stopping alkaline hydrolysis when the content of monochlorobenzyl is less than or equal to 0.2%, and cooling, washing and layering to obtain crude aldehyde liquid, and putting the crude aldehyde liquid into a crude aldehyde tank for use in a refined aldehyde post of the next procedure.
5. Refining
And (3) pumping the hydrolyzed crude aldehyde liquid to a tower III kettle, opening a steam inlet valve, heating to 125 ℃, opening a tower top condenser to cool water, performing reduced pressure rectification, wherein the front distillate enters a tower top front distillate groove through the tower top condenser and is returned to the hydrolysis kettle for recycling, and the o-chlorobenzaldehyde is purified and then enters a tower top liquid tank III from the tower top condenser and is put into an o-chlorobenzaldehyde finished product groove for packaging.
The purity of the o-chlorobenzaldehyde product obtained in the embodiment is 99.7%, and the total yield of the o-chlorobenzaldehyde product is 92.5%.
Example 3:
the production process of the embodiment is as follows:
1. chlorination of
Measuring o-chlorotoluene by a feed pump, then feeding the o-chlorotoluene into a chlorination reaction tower, adding 0.1% azobisisobutyronitrile as an initiator, starting a light source, opening a condenser cooling water at the top of the tower, heating to 100 ℃, introducing chlorine gas in a sectional measurement manner, controlling the reaction temperature to be about 130 ℃, stopping introducing chlorine when the specific gravity of a chlorination solution reaches 1.34 under the condition of 20 ℃, putting the chlorination solution into an alkaline tank, quantitatively adding 10% industrial liquid alkali, starting stirring for 2 hours, measuring the pH value of the chlorination solution, stopping stirring when the pH value of the chlorination solution is 7, standing for layering, and then putting the chlorination solution into a chlorination solution storage tank; and hydrogen chloride gas generated in the chlorination reaction is recycled by the tower top condenser and enters a hydrochloric acid recycling system.
2. Fractional distillation
Firstly, pumping a chlorination solution from a chlorination solution storage tank to a tower I, opening a steam inlet valve, heating to 150 ℃, opening a tower top condenser for cooling water, wherein chlorotoluene is purified by reduced pressure rectification (the content is more than or equal to 80.0%) and then is discharged from a tower top front fraction tank to a chlorotoluene recovery storage tank, and then is recycled in a chlorination tower, after the chlorobenzyl chloride is purified by reduced pressure rectification (the content is more than or equal to 99.0%), the monochlorobenzyl chloride is discharged from a tower top liquid tank to a chlorobenzyl chloride finished product tank for packaging, and after the dichlorobenzyl chloride crude product in the tower kettle is purified (the monochlorobenzyl chloride is controlled to be less than or equal to 10.0%), the monochlorobenzyl chloride crude product is discharged to a tower bottom liquid tank of the tower I to be used as a feed of a tower II.
3. Rectification
Pumping the purified crude product of the dichlorobenzyl from a tank of a tower I to a feeding head tank of a tower II, feeding the crude product of the dichlorobenzyl into the tank of the tower II through a rotameter, opening a steam inlet valve, heating to 150 ℃, opening a condenser at the top of the tower to cool water, recovering and purifying the ortho-chlorobenzyl chloride in the crude product of the dichlorobenzyl in the tower through reduced pressure rectification, feeding the crude product of the dichlorobenzyl into the tank of the tower II from the condenser at the top of the tower, and then putting the crude product of the dichlorobenzyl into a chlorination liquid storage tank for recycling, wherein when the content of the monochlorobenzyl chloride in the dichlorobenzyl in the tower kettle is less than or equal to 0.2%, the crude product of the dichlorobenzyl in the tower is put into the tank of the tower II for the next process.
4. Hydrolysis, alkaline hydrolysis
Pumping purified dichlorobenzyl from a liquid tank of a tower II to a dichlorosilane head tank, then putting the dichlorobenzyl into a hydrolysis kettle, adding 0.2% of catalyst namely active zinc oxide, starting stirring, opening condenser cooling water, heating to 130 ℃, then opening an outlet valve of the water head tank, continuously metering and dripping water, stopping hydrolysis when the content of dichlorobenzyl is less than or equal to 0.1%, cooling to 80 ℃, quantitatively adding 30% pure alkali liquor from the alkali liquor head tank for alkaline hydrolysis for 2-3 hours, stopping alkaline hydrolysis when the content of monochlorobenzyl is less than or equal to 0.2%, and cooling, washing and layering to obtain crude aldehyde liquid, and putting the crude aldehyde liquid into a crude aldehyde tank for use in a refined aldehyde post of the next procedure.
5. Refining
And (3) pumping the hydrolyzed crude aldehyde liquid to a tower III kettle, opening a steam inlet valve, heating to 130 ℃, opening a tower top condenser to cool water, performing reduced pressure rectification, wherein the front distillate enters a tower top front distillate groove through the tower top condenser and is returned to the hydrolysis kettle for recycling, and the o-chlorobenzaldehyde is purified and then enters a tower top liquid tank III from the tower top condenser and is put into an o-chlorobenzaldehyde finished product groove for packaging.
The purity of the o-chlorobenzaldehyde product obtained in the embodiment is 99.6%, and the total yield of the o-chlorobenzaldehyde product is 92.6%.
According to the three embodiments, the purity of the o-chlorobenzaldehyde prepared by the invention is over 99.5 percent and far exceeds 95 percent in the production process in the prior art; the total yield of o-chlorobenzaldehyde is over 92 percent and far exceeds 82 percent in the production process in the prior art, and the technical advantages of the production process in the invention are fully proved.
Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.
Claims (9)
1. A process for producing o-chlorobenzaldehyde by a chlorination distillation method selects o-chlorotoluene and chlorine as raw materials, and is characterized in that the production process comprises the following steps:
(1) chlorination: measuring o-chlorotoluene by a feed pump, then feeding the o-chlorotoluene into a chlorination reaction tower, adding an initiator, starting a light source, opening a condenser cooling water on the top of the tower, heating the tower to 100 ℃, feeding chlorine gas in a sectional measurement manner, controlling the reaction temperature to be at 120-130 ℃, stopping feeding the chlorine gas when the specific gravity of a chlorination solution reaches 1.34 under the condition of 20 ℃, putting the chlorination solution into an alkaline tank, quantitatively adding alkali for neutralization, stirring for 2 hours, measuring the pH value of the chlorination solution, stopping stirring when the pH value of the chlorination solution is 6-7, standing for layering, and then putting the chlorination solution into a chlorination solution storage tank;
(2) fractional distillation: firstly, pumping a chlorination solution from a chlorination solution storage tank to a tower I kettle, heating to 150 ℃, opening a condenser cooling water at the top of the tower, separating chlorotoluene and monochlorobenzyl by reduced pressure fractionation, purifying a crude dichlorobenzyl product in the tower kettle, controlling the monochlorobenzyl to be less than or equal to 10.0%, and putting the purified dichlorobenzyl product into a tower I kettle liquid tank to serve as a feed of a tower II;
(3) and (3) rectification: pumping the purified crude product of dichlorobenzyl from a liquid tank of a tower I to a feeding head tank of a tower II, feeding the crude product of dichlorobenzyl into the tower II through a rotameter, heating to raise the temperature to 140 ℃ and open a condenser at the top of the tower for cooling water, separating the o-chlorobenzyl chloride and the residual monochlorobenzyl chloride in the crude product of dichlorobenzyl in the tower kettle through reduced pressure rectification, and when the content of monochlorobenzyl chloride in the dichlorobenzyl in the tower kettle is less than or equal to 0.2%, putting the crude product of dichlorobenzyl in the tower kettle to the liquid tank of the tower II for the next process;
(4) hydrolysis and alkaline hydrolysis: pumping purified benzyl dichloride from a liquid tank of a tower II to a dichloro head tank, then putting the dichloro head tank into a hydrolysis kettle, then adding a catalyst, starting stirring, opening cooling water of a condenser, heating to 120-130 ℃, then opening an outlet valve of the water head tank, continuously measuring and dripping water, stopping hydrolysis when the content of benzyl dichloride is less than or equal to 0.1%, cooling to 80 ℃, quantitatively adding 30% pure alkali liquor from the alkali liquor head tank for alkaline hydrolysis for 2-3 hours, stopping alkaline hydrolysis when the content of benzyl monochloride is less than or equal to 0.2%, cooling, washing and layering to obtain a crude aldehyde liquid, and putting the crude aldehyde liquid into a crude aldehyde tank;
(5) refining: and (3) pumping the hydrolyzed crude aldehyde liquid to a tower III kettle, heating to 120-130 ℃, opening a tower top condenser to cool water, performing reduced pressure rectification, wherein the front fraction liquid enters a tower top front fraction groove through the tower top condenser and is returned to the hydrolysis kettle for recycling, and the o-chlorobenzaldehyde is purified and then enters a tower top liquid groove III from the tower top condenser and is put into an o-chlorobenzaldehyde finished product groove for packaging.
2. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in claim 1, wherein: in the chlorination step, hydrogen chloride gas generated in the chlorination reaction is recycled by a tower top condenser and enters a hydrochloric acid recycling system.
3. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in claim 2, wherein: in the fractionating step, the chlorotoluene is decompressed, fractionated and purified, then is discharged from a front fraction tank at the top of the tower to a chlorotoluene recovery storage tank, and is recycled in a chlorination tower, and the monochlorobenzene at the top of the tower is decompressed, fractionated and purified, then is discharged from a liquid tank at the top of the tower I to a finished chlorobenzyl product tank for packaging.
4. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in claim 3, wherein: in the rectification step, the o-chlorobenzyl chloride in the crude dichlorobenzyl in the tower kettle is recovered and purified through reduced pressure rectification, then enters a liquid tank at the top of the tower II from a condenser at the top of the tower, and then is placed in a chlorination liquid storage tank for recycling.
5. The process for producing o-chlorobenzaldehyde by chlorination and rectification method according to claim 4, wherein the production process comprises the following steps:
(1) chlorination: measuring o-chlorotoluene by a feed pump, then feeding the o-chlorotoluene into a chlorination reaction tower, adding an initiator, starting a light source, starting a condenser at the top of the tower to cool water, heating the temperature to 100 ℃, feeding chlorine gas in a sectional measurement manner, controlling the reaction temperature to be 125 ℃, stopping feeding chlorine when the specific gravity of a chlorination solution reaches 1.34 under the condition of 20 ℃, putting the chlorination solution into an alkaline washing tank, quantitatively adding alkali for neutralization, starting stirring for 2 hours, measuring the pH value of the chlorination solution, stopping stirring when the pH value of the chlorination solution is 6.5, standing for layering, and then putting the chlorination solution into a chlorination solution storage tank; hydrogen chloride gas generated in the chlorination reaction is recycled by a tower top condenser and enters a hydrochloric acid recycling system;
(2) fractional distillation: firstly, pumping a chlorination solution from a chlorination solution storage tank to a tower I, opening a steam inlet valve, heating to 145 ℃, opening a tower top condenser for cooling water, wherein chlorotoluene is purified by reduced pressure rectification and then is discharged from a tower top front cut tank to a chlorotoluene recovery storage tank, and is re-introduced into a chlorination tower for recycling, benzyl chloride at the tower top is purified by reduced pressure rectification and then is discharged from a tower top liquid tank of the tower I to a benzyl chloride finished product tank for packaging, a benzyl dichloride crude product at the tower kettle is purified, the benzyl chloride is controlled to be less than or equal to 10.0% by purification, and is discharged to a tower bottom liquid tank of the tower I after purification to be used as a feed of a tower II;
(3) and (3) rectification: pumping the purified crude product of the dichlorobenzyl from a tank of a tower I to a feeding head tank of a tower II, feeding the crude product of the dichlorobenzyl into a tower II through a rotameter, opening a steam inlet valve, heating to 145 ℃, opening a condenser at the top of the tower to cool water, recovering and purifying the ortho-chlorobenzyl chloride in the crude product of the dichlorobenzyl in the tower through reduced pressure rectification, feeding the crude product of the dichlorobenzyl into a tank of the tower II from the condenser at the top of the tower, and then putting the crude product of the dichlorobenzyl into a chlorination liquid storage tank for recycling, wherein when the content of monochlorobenzyl chloride in the dichlorobenzyl in the tower is less than or equal to 0.2%, the crude product of the dichlorobenzyl in the tower is put into the tank of the tower II for the next process;
(4) hydrolysis and alkaline hydrolysis: pumping purified benzyl dichloride from a liquid tank of a tower II to a dichloro head tank, then putting the dichloro head tank into a hydrolysis kettle, then adding a catalyst, starting stirring, opening a condenser to cool water, heating to 125 ℃, then opening an outlet valve of the water head tank, continuously adding dropwise water in a metered manner, stopping hydrolysis when the content of the benzyl dichloride is less than or equal to 0.1%, cooling to 80 ℃, quantitatively adding 30% pure alkali liquor from the alkali liquor head tank for alkaline hydrolysis for 2-3 hours, stopping alkaline hydrolysis when the content of benzyl monochloride is less than or equal to 0.2%, and cooling, washing and layering to obtain crude aldehyde liquid, putting the crude aldehyde liquid into a crude aldehyde tank for use in a fine aldehyde post of the next procedure;
(5) refining: and (3) pumping the hydrolyzed crude aldehyde liquid to a tower III kettle, opening a steam inlet valve, heating to 125 ℃, opening a tower top condenser to cool water, performing reduced pressure rectification, wherein the front distillate enters a tower top front distillate groove through the tower top condenser and is returned to the hydrolysis kettle for recycling, and the o-chlorobenzaldehyde is purified and then enters a tower top liquid tank III from the tower top condenser and is put into an o-chlorobenzaldehyde finished product groove for packaging.
6. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in claim 5, wherein: and the chlorination reaction tower, the tower I, the tower II and the tower III are provided with steam pipelines, and steam is adopted for heating.
7. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in any one of claims 1 to 6, wherein: the alkali added in the chlorination step is 10% of industrial liquid alkali or 10% of industrial caustic sludge.
8. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in any one of claims 1 to 6, wherein: in the chlorination step, the initiator is 0.1% azobisisobutyronitrile.
9. The process for producing o-chlorobenzaldehyde by chlorination and rectification as claimed in any one of claims 1 to 6, wherein: in the hydrolysis and alkaline hydrolysis steps, the catalyst is 0.2% of active zinc oxide.
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Denomination of invention: A process for producing ortho chlorobenzaldehyde by chlorination distillation Granted publication date: 20230203 Pledgee: Hubei Dangyang Rural Commercial Bank Co.,Ltd. Wangdian Branch Pledgor: HUBEI YUANHUAN INDUSTRIAL INVESTMENT Co.,Ltd. Registration number: Y2024980010206 |