CN112521251A - Method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde - Google Patents

Method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde Download PDF

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CN112521251A
CN112521251A CN202110033574.9A CN202110033574A CN112521251A CN 112521251 A CN112521251 A CN 112521251A CN 202110033574 A CN202110033574 A CN 202110033574A CN 112521251 A CN112521251 A CN 112521251A
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methanol
isobutyraldehyde
formaldehyde
gas
npg
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孙涛
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Zhanhua Yukai New Material Technology Co ltd
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Zhanhua Yukai New Material Technology Co ltd
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    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/132Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group
    • C07C29/136Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH
    • C07C29/14Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of a —CHO group
    • C07C29/141Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of a —CHO group with hydrogen or hydrogen-containing gases
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/74Separation; Purification; Use of additives, e.g. for stabilisation
    • C07C29/76Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/27Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
    • C07C45/32Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen
    • C07C45/37Preparation 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
    • C07C45/38Preparation 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
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/61Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
    • C07C45/67Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
    • C07C45/68Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
    • C07C45/72Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction of compounds containing >C = O groups with the same or other compounds containing >C = O groups
    • C07C45/75Reactions with formaldehyde
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/78Separation; Purification; Stabilisation; Use of additives
    • C07C45/81Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
    • C07C45/82Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23GCREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/04Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste liquors, e.g. sulfite liquors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23GCREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/06Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases

Abstract

The invention discloses a method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde, which comprises the following steps: step one, oxidizing methanol; step two, aldehyde condensation; step three, HPA purification; step four, HPA hydrogenation; step five, NPG refining; and step six, waste incineration. The invention has the advantages of low energy consumption in the production process and low environmental pollution.

Description

Method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde
Technical Field
The invention relates to the technical field of pentanediol production, in particular to a method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde.
Background
Polyhydric alcohols or polyols are of great economic interest as condensation components for forming polyesters or polyurethanes, synthetic resin coatings, lubricants and plasticizers. In this context, the polyhydric alcohols of interest are in particular those obtained by mixed aldol addition of formaldehyde to isobutyraldehyde or n-butyraldehyde. The aldol addition between formaldehyde and the appropriate butyraldehyde first forms an aldehyde intermediate product, which must then be reduced to the polyhydroxy alcohol. An industrially important polyhydric alcohol which can be obtained by this process is neopentyl glycol (NPG,2, 2-dimethylpropane-1, 3-diol) formed by the mixed aldol condensation of formaldehyde and isobutyraldehyde.
The aldol addition is carried out in the presence of a basic catalyst such as an alkali metal hydroxide or an aliphatic amine and initially produces an isolatable Hydroxypivalaldehyde (HPA) intermediate product. This intermediate can then be converted to neopentyl glycol with an excess of formaldehyde according to the Cannizzaro reaction to form one equivalent of formate salt. In the variant of this reduction step, formate is thus obtained as a by-product, the economic efficiency of this process variant also depending on the commercial opportunity for formate. However, the catalytic hydrogenation of hydroxypivalaldehyde with metal catalysts in the gas and liquid phases has also been practiced industrially. According to EP0278106a1, it has been found that suitable hydrogenation catalysts are nickel catalysts. The hydrogenation step in the process according to EP0484800a2 uses a catalyst based on copper, zinc and zirconium.
Copper chromite catalysts are also commonly used for the hydrogenation of hydroxypivalaldehyde. Copper chromite catalysts often contain other metals as activators, such as barium, cadmium, magnesium, manganese, and/or rare earth metals. According to US4855515, manganese-doped copper chromite catalysts are particularly suitable in the hydrogenation of aldol condensation products of formaldehyde with isobutyraldehyde. WO98/29374A1 discloses the use of barium-doped copper chromite catalysts for the hydrogenation of hydroxypivalaldehyde in methanol solution.
Neopentyl glycol is of great economic importance as an industrially produced product, and there is therefore always a need for improvements in the known processes for preparing neopentyl glycol, whether by improving the yield, by better utilization of plant equipment, or by reducing the energy input.
Disclosure of Invention
The invention aims to solve the problems and designs a method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde.
The technical scheme of the invention is that the method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde comprises the following steps:
step one, oxidizing methanol, uniformly mixing the methanol and air, evaporating, introducing steam to prepare ternary methanol-steam-air gas, carrying out oxidation reaction on the ternary gas and a catalyst layer, converting the methanol in the ternary gas into formaldehyde to obtain a generated gas containing the formaldehyde, cooling the generated gas to form a gas-liquid mixture at about 90 ℃, reacting a liquid phase in the gas-liquid mixture with an absorption liquid to obtain a mixed liquid containing the formaldehyde, and circularly cooling the mixed liquid containing the formaldehyde to form a reaction material;
step two, aldehyde condensation, namely mixing the formaldehyde mixed solution with 99.5 percent of isobutyraldehyde and 99.9 percent of trimethylamine, then mixing the mixture with the reaction material after circulation cooling to carry out primary condensation reaction, and carrying out secondary condensation reaction on the reaction material obtained after the primary condensation reaction to generate hydroxyl pivalaldehyde;
purifying HPA, namely distilling hydroxyl pivalic aldehyde to obtain a condensate aqueous solution mainly containing hydroxyl pivalic aldehyde, boosting the pressure of the condensate aqueous solution, sending the condensate aqueous solution into a first tank for caching, adding a small amount of trimethylamine into the material in the first tank for mixing, and ensuring that the pH value of the material is stabilized at 8.5;
step four, HPA hydrogenation, mixing the hydroxyl tert-valeraldehyde aqueous solution with the hydrogen after pressure boosting, reacting through a catalyst bed layer to obtain a hydrogenation product of the hydroxyl tert-valeraldehyde, conveying the hydrogenation product of the hydroxyl tert-valeraldehyde to a tank II for decompression and degassing, conveying the liquid in the tank II to a tank III for further decompression to 0.1Mpa for degassing again;
and step five, NPG refining, namely evaporating the hydrogenated product of the hydroxyl pivalic aldehyde degassed twice in a negative pressure environment to obtain a product with the main component of crude NPG, then carrying out NPG de-heavy purification on the product of the crude NPG under the negative pressure condition to obtain an NPG finished product, and preparing the obtained NPG finished product into an NPG aqueous solution.
And step six, waste incineration, wherein the incineration is to put the waste gas and the residues generated in the step six into the incineration.
The ratio of air to methanol in step one was 1.32(m ethanol): 1 (kg), the temperature in the evaporation process is 44-45 ℃, and the pressure is 10-50 KPa.
The proportion of the water vapor added in the first step is 1: 1.
in the second step, the content of formaldehyde in the formaldehyde mixed solution is 37%, and the mixing ratio (mass ratio) of the formaldehyde mixed solution, 99.5% of isobutyraldehyde and 99.9% of trimethylamine is 75:90: 0.15.
And in the second step, the cooling medium adopted for external heat exchange in the reaction process is hot water at 65 ℃ so as to ensure the stability of the stable condensation reaction.
In the third step, the distilled substances obtained by distilling the hydroxytetravaleraldehyde mainly comprise water, formic acid, trimethylamine, isobutyraldehyde and some byproducts.
And the low-boiling-point organic matter in the fifth step comprises methanol, organic amine, isobutanol and a small amount of water.
Advantageous effects
The method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde, which is prepared by the technical scheme of the invention, has the following advantages:
1. the method has the advantages of high draft conversion rate and high yield, can realize the production process of high-purity hydrogenated neopentyl glycol by relying on methanol and isobutyraldehyde, and can effectively eliminate the formation of high-boiling-point substances in the hydrogenation stage;
2. the method has the advantages that a large amount of waste heat is recycled in the production process, the energy consumption of production and processing is effectively reduced, waste gas and residual substances are eliminated in the production process in an incineration mode, zero emission is effectively realized, and the pollution of chemical production to the environment is avoided.
Drawings
FIG. 1 is a process flow diagram of a process for producing high purity hydrogenated neopentyl glycol from methanol and isobutyraldehyde in accordance with the present invention.
Detailed Description
The invention is described in detail below with reference to the drawings, as shown in FIG. 1;
the invention of the application is that the method comprises the following steps:
firstly, oxidizing methanol, uniformly mixing the methanol and air, evaporating, introducing steam to prepare ternary gas of methanol, steam and air, allowing the ternary gas to generate an oxidation reaction on a catalyst layer, converting methanol and oxygen in the ternary gas into formaldehyde to further obtain generated gas containing the formaldehyde, cooling the generated gas to form a gas-liquid mixture at about 90 ℃, allowing a liquid phase in the gas-liquid mixture to react with an absorption liquid to obtain a mixed liquid containing the formaldehyde, and circularly cooling the mixed liquid containing the formaldehyde to form a reaction material;
step two, aldehyde condensation, namely mixing the formaldehyde mixed solution with 99.5 percent of isobutyraldehyde and 99.9 percent of trimethylamine, then mixing the mixture with the reaction material after circulation cooling to carry out primary condensation reaction, and carrying out secondary condensation reaction on the reaction material obtained after the primary condensation reaction to generate hydroxyl pivalaldehyde;
purifying HPA, namely distilling hydroxyl pivalic aldehyde to obtain a condensate aqueous solution mainly containing hydroxyl pivalic aldehyde, boosting the pressure of the condensate aqueous solution, sending the condensate aqueous solution into a first tank for caching, adding a small amount of trimethylamine into the material in the first tank for mixing, and ensuring that the pH value of the material is stabilized at 8.5;
step four, HPA hydrogenation, mixing the hydroxyl tert-valeraldehyde aqueous solution with the hydrogen after pressure boosting, reacting through a catalyst bed layer to obtain a hydrogenation product of the hydroxyl tert-valeraldehyde, conveying the hydrogenation product of the hydroxyl tert-valeraldehyde to a tank II for decompression and degassing, conveying the liquid in the tank II to a tank III for further decompression to 0.1Mpa for degassing again;
and step five, NPG refining, namely evaporating the hydrogenated product of the hydroxyl pivalic aldehyde degassed twice in a negative pressure environment to obtain a product with the main component of crude NPG, then carrying out NPG de-heavy purification on the product of the crude NPG under the negative pressure condition to obtain an NPG finished product, and preparing the obtained NPG finished product into an NPG aqueous solution.
And step six, burning the waste, namely burning the waste gas and the residues generated in the step in a burning furnace.
The invention also resides in a method comprising in step one, a ratio of air to methanol of 1.32 (mn): 1 (kg), the temperature in the evaporation process is 44-45 ℃, and the pressure is 10-50 Kpa; the proportion of the water vapor added in the first step is 1: 1; in the second step, the formaldehyde mixed solution contains 37% of formaldehyde, and the mixed ratio (mass ratio) of the formaldehyde mixed solution, 99.5% of isobutyraldehyde and 99.9% of trimethylamine is 75:90: 0.15; in the second step, the cooling medium adopted for external heat exchange in the reaction process is hot water at 65 ℃ so as to ensure the stability of the stable condensation reaction; in the third step, distilled matters obtained by distilling the hydroxyl pivalaldehyde mainly comprise water, formic acid, trimethylamine, isobutyraldehyde and some byproducts; and the low-boiling-point organic matter in the fifth step comprises methanol, organic amine, isobutanol and a small amount of water.
In the implementation process of the technical scheme, the production method comprises the following steps:
step one, methanol is oxidized, the methanol and air are uniformly mixed and conveyed to a first heat exchanger for evaporation, water vapor is introduced into binary gas generated by evaporation to prepare methanol-water vapor-air ternary gas, the ternary gas is introduced into the top of a first reactor, the ternary gas passes through a catalyst layer in the first reactor from top to bottom, the temperature in the first reactor is controlled to be 630-660 ℃, methanol and oxygen in the ternary gas are oxidized after contacting the catalyst layer and then are converted into formaldehyde to further obtain generated gas containing the formaldehyde, a tubular condenser is arranged at the bottom layer of the first reactor, the generated gas containing the formaldehyde after being converted by the catalyst enters a tubular cooler for cooling to form a gas-liquid mixture at about 90 ℃, the gas-liquid mixture is introduced into the bottom of the first tower, absorption liquid is introduced into the top of the first tower, the absorption liquid comes from the second tower, and is sprayed to the bottom of the first tower in a spraying manner from the top of the first tower, and reacting with the liquid phase in the gas-liquid mixture at the bottom of the first tower to obtain a mixed solution containing formaldehyde, wherein one part of the mixed solution containing formaldehyde is sent into the second reactor by the first pump, and the other part of the mixed solution containing formaldehyde is subjected to circulating cooling to form a reaction material.
Step two, aldehyde condensation, namely mixing formaldehyde mixed liquor sent into a reactor II by a pump I with 99.5 percent of isobutyraldehyde and 99.9 percent of trimethylamine, mixing the mixed liquor with the reaction materials after circulation cooling by an ejector at the bottom of the reactor II, and sending the mixture into the reactor II to carry out primary condensation reaction; after the first-stage condensation reaction is finished, pumping out the reaction materials in the second reactor by a second pump, cooling by a second heat exchanger to remove reaction heat, then re-entering a part of the reaction materials into the second reactor and mixing the subsequent entering materials in the second reactor, and introducing the other part of the reaction materials into a third reactor by the second pump to continue condensation reaction to generate hydroxyl pivalaldehyde; removing reaction heat of materials in the third reactor through an external circulating system, leading out a part of hydroxyl pivalaldehyde in the third reactor from a third pump, and feeding the part of hydroxyl pivalaldehyde into a third tower;
and step three, HPA purification, namely, feeding the hydroxyl pivalic aldehyde led out from the reactor III into the upper part of a tower III for distillation, heating a reboiling heat exchanger IV in the tower III by using rich steam from a methanol oxidation process, wherein the pressure in the tower III is 15-20Kpa, remaining the hydroxyl pivalic aldehyde in a material at the bottom of the tower III after distillation in the tower III and using the hydroxyl pivalic aldehyde as a main condensation compound aqueous solution, boosting the pressure of the condensation compound aqueous solution by a pump IV, feeding one path of the condensation compound aqueous solution into a heat exchanger IV in the tower III, feeding the other path of the condensation compound aqueous solution into a tank I buffer memory through a heat exchanger VII, mixing the material passing through the heat exchanger VII and a small amount of trimethylamine to ensure that the pH value of the material is stabilized at 8.5, and feeding the material stored in the tank I into the reactor IV for hydrogenation by increasing.
Step four, HPA hydrogenation, wherein a hydroxyl pivalaldehyde aqueous solution from a tank I is converged with a four-external circulation pipeline of a reactor and enters the reactor IV from the top, the hydroxyl pivalaldehyde aqueous solution and the hydrogen after pressure boosting are mixed at the top of the reactor IV, and descend in the reactor IV to pass through a catalyst bed layer for reaction, reaction heat is led out through a heat exchanger VIII through hot water at 65 ℃ through external circulation, the temperature in the reactor IV is 95-110 ℃, and the pressure is 4.0 Mpa; feeding part of hydrogen and hydrogenation liquid material into a fifth reactor while ensuring the heat dissipation of circulating cooling by reaction liquid in the fourth reactor, and continuously carrying out hydrogenation reaction through a catalyst bed layer, wherein the concentration of hydroxypivalaldehyde is ensured to be less than 0.05% at the outlet of the fifth reactor, the conversion rate of HPA reaches 99%, the temperature of the hydrogenation reaction in the fifth reactor is 97-110 ℃, and the pressure is 4.0 MPa; the hydrogenation product of the hydroxyl pivalaldehyde is conveyed to a second tank for decompression through pressure, the waste hydrogen gas separated from the second tank is introduced into an incinerator for incineration, the liquid in the second tank is conveyed to a third tank for further decompression to 0.1Mpa for degassing, the separated gas is introduced into the incinerator for incineration, and the liquid in the third tank is conveyed to a fourth tower through self-pressure to remove light component impurities.
Step five, NPG refining, wherein the pressure in the tower four is-0.085 Mpa, the negative pressure in the tower four is generated by manufacturing a vacuum ejector I, light components evaporated from the top of the tower four are cooled by a heat exchanger nine at the top of the tower four, separated non-condensable gas is low-boiling-point organic matters, the low-boiling-point organic matters are sent to an incinerator for incineration treatment by the vacuum ejector I, a liquid phase separated by the heat exchanger nine enters a tank four, then the pressure of the liquid phase is increased by a pump seven, and a part of the liquid phase is taken as the top reflux of the tower four, and the reflux ratio is 0.3: 1, sending the other part of the heavy components to an incinerator for incineration, adopting a siphon reboiler for a reboiling heat exchanger of a tower IV, mainly using crude NPG as heavy components separated from the tower bottom, and conveying the heavy components to a tower V through a pump VI; and (3) carrying out NPG heavy removal and purification on the tower five under the pressure condition of-0.095 Mpa, generating negative pressure by a steam jet pump II, condensing the tower top material of the tower five into a liquid phase by a heat exchanger eleven, feeding the liquid phase into a tank five, refluxing a part of the liquid phase in the tank five as the top of the tower five after passing through a pump nine, and conveying the rest of the liquid phase as a NPG finished product to prepare an NPG aqueous solution or conveying the liquid phase to a flaker.
Step six, burning waste, namely conveying tail gas from the tower II, excessive waste gas at the top of the tower III, released waste gas of the tank II, released waste gas of the tank III and gas-phase waste gas of the vacuum ejector I to a burner at the top of the incinerator through a pipeline for burning; and the waste liquid of the tank IV is sent to a nozzle at the middle upper part of the incinerator through a pump VII, the heavy component at the bottom of the tower V is sent to the nozzle at the middle upper part of the incinerator through a pump VIII, the incinerator controls the oxygen content of the flue gas through an oxygenating fan, the mixed flue gas is combusted to 1100 ℃ and stays in a first combustion chamber and a second combustion chamber of the incinerator for more than 2 seconds, and the waste heat of the flue gas is recovered through a waste heat furnace.
The ratio of air to methanol fed to heat exchanger one in step one was 1.32(m ethanol): 1 (kg), the temperature in the heat exchanger is 44-45 ℃, and the pressure is 10-50 KPa.
And (3) surplus steam generated by the oxidation reaction in the first tower in the step one can be used for the third tower to heat the heat exchanger IV, mixed liquid containing formaldehyde is formed after the absorption liquid reacts with liquid phase in the gas-liquid mixture at the bottom of the first tower, the mixed liquid is sent into the second reactor by the first pump, gas phase in the gas-liquid mixture enters the bottom of the second tower from the top of the first tower from bottom to top in the first tower, soft water is introduced into the top of the second tower, the soft water is absorbed with the gas phase at the bottom of the second tower from top to bottom in the second tower from the top of the second tower, and tail gas discharged from the top of the second tower enters.
In the second step, the content of formaldehyde in the formaldehyde mixed solution sent into the second reactor by the first pump is 37 percent, the mixing ratio (mass ratio) of the formaldehyde mixed solution, 99.5 percent of isobutyraldehyde and 99.9 percent of trimethylamine is 75:90:0.15, the temperature in the second reactor is 70 ℃, and the pressure is 0.25 MPa.
In the second step, the cooling medium adopted by the external heat exchangers of the second reactor and the third reactor is hot water with the temperature of 65 ℃ so as to ensure the stability of the stable condensation reaction. The pressure of the condensation reactor is controlled and the excess gas is sent to the third column.
And (3) the substances evaporated from the top of the third tower in the third step are mainly water, formic acid, trimethylamine, isobutyraldehyde and some byproducts, and are cooled by a fifth heat exchanger and a sixth heat exchanger, and then the cooled substances are sent back to an inlet feed pipeline of the second reactor for reuse by a fifth pump, the fourth heat exchanger is a falling film reboiler, and the redundant gas generated by the third tower is sent to an incinerator for incineration.
The low boiling point organic matter in the fifth step comprises methanol, organic amine, isobutanol and a small amount of water; and a tower bottom reboiling heat exchanger ten of the tower five adopts a falling film evaporator, forced circulation is carried out by a pump eight, and tower bottom heavy components of the tower five are conveyed to an incinerator for incineration by a pump ten.
In the sixth step, 2.2Mpa saturated steam is produced in the incinerator system, and is sent to a reboiling heat exchanger ten of a tower four and a reboiling heat exchanger ten of a tower bottom of a tower five, and the surplus steam is decompressed to 0.5Mpa by a decompression valve to supply to a device for heat tracing.
In the whole method, the first tower and the second tower are absorption towers, and the third tower, the fourth tower and the fifth tower are purification towers.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation. The use of the phrase "comprising one of the elements does not exclude the presence of other like elements in the process, method, article, or apparatus that comprises the element.
The technical solutions described above only represent the preferred technical solutions of the present invention, and some possible modifications to some parts of the technical solutions by those skilled in the art all represent the principles of the present invention, and fall within the protection scope of the present invention.

Claims (7)

1. A method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde is characterized by comprising the following steps:
step one, oxidizing methanol, uniformly mixing the methanol and air, evaporating, introducing steam to prepare ternary gas of methanol, steam and air, allowing the ternary gas to pass through a catalyst layer for oxidation reaction, converting methanol and oxygen in the ternary gas into formaldehyde to obtain generated gas containing the formaldehyde, cooling the generated gas to form a gas-liquid mixture at about 90 ℃, allowing a liquid phase in the gas-liquid mixture to react with an absorption liquid to obtain a mixed liquid containing the formaldehyde, and circularly cooling the mixed liquid containing the formaldehyde to form a reaction material;
step two, aldehyde condensation, namely mixing the formaldehyde mixed solution with 99.5 percent of isobutyraldehyde and 99.9 percent of trimethylamine, then mixing the mixture with the reaction materials after circulation cooling to carry out primary condensation reaction, and carrying out secondary condensation reaction on the reaction materials obtained after the primary condensation reaction is finished to generate Hydroxyl Pivalaldehyde (HPA);
purifying HPA, namely distilling the condensed hydroxypivalaldehyde solution to obtain a condensate aqueous solution mainly containing hydroxypivalaldehyde, boosting the pressure of the condensate aqueous solution, sending the condensate aqueous solution into a first tank for caching, adding a small amount of trimethylamine into the material in the first tank for mixing, and ensuring that the pH value of the material is stabilized at 8.5;
step four, HPA hydrogenation, mixing the hydroxyl tert-valeraldehyde aqueous solution with the hydrogen after pressure boosting, reacting through a catalyst bed layer to obtain a hydrogenation product of the hydroxyl tert-valeraldehyde, conveying the hydrogenation product of the hydroxyl tert-valeraldehyde to a tank II for decompression and degassing, conveying the liquid in the tank II to a tank III for further decompression to 0.1Mpa for degassing again;
step five, NPG refining, namely evaporating the hydrogenation product of the hydroxyl pivalic aldehyde degassed twice in a negative pressure environment to obtain a product with the main component of crude NPG, then carrying out NPG de-heavy purification on the product of the crude NPG under the negative pressure condition to obtain an NPG finished product, and preparing the obtained NPG finished product into an NPG aqueous solution;
and step six, burning the waste, namely burning the waste gas and the residues generated in the step in a burning furnace.
2. The process of claim 1, wherein the ratio of air to methanol in step one is 1.32 (mn): 1 (kg), the temperature in the evaporation process is 44-45 ℃, and the pressure is 10-50 KPa.
3. The method for producing high-purity hydrogenated neopentyl glycol from methanol and isobutyraldehyde according to claim 1, wherein the ratio of the steam added in the first step is 1: 1.
4. the method of claim 1, wherein the formaldehyde content of the formaldehyde mixed solution in the second step is 37%, and the mixing ratio (mass ratio) of the formaldehyde mixed solution, 99.5% of isobutyraldehyde and 99.9% of trimethylamine is 75:90: 0.15.
5. The method for producing high-purity hydrogenated neopentyl glycol from methanol and isobutyraldehyde according to claim 1, wherein the cooling medium used for external heat exchange during the reaction in the second step is hot water of 65 ℃ to ensure stable condensation reaction.
6. The process of claim 1, wherein the distilled product of hydroxypivalaldehyde from methanol and isobutyraldehyde is mainly water, formic acid, trimethylamine, isobutyraldehyde and byproducts.
7. The method for producing high-purity hydrogenated neopentyl glycol from methanol and isobutyraldehyde according to claim 1, wherein the low-boiling organic substance in the fifth step comprises methanol, organic amine, isobutanol and a small amount of water.
CN202110033574.9A 2021-01-12 2021-01-12 Method for producing high-purity hydrogenated neopentyl glycol by using methanol and isobutyraldehyde Pending CN112521251A (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103130611A (en) * 2011-11-23 2013-06-05 山东华鲁恒升化工股份有限公司 Neopentyl glycol condensation hydrogenation production process and device thereof
CN105418390A (en) * 2015-11-17 2016-03-23 扬州市众鑫化工有限公司 Energy-saving type continuous and circular production technology method for formaldehyde

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103130611A (en) * 2011-11-23 2013-06-05 山东华鲁恒升化工股份有限公司 Neopentyl glycol condensation hydrogenation production process and device thereof
CN105418390A (en) * 2015-11-17 2016-03-23 扬州市众鑫化工有限公司 Energy-saving type continuous and circular production technology method for formaldehyde

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