CN117326985A - Industrialized synthesis process of isophorone dicarbamic acid n-butyl ester - Google Patents

Industrialized synthesis process of isophorone dicarbamic acid n-butyl ester Download PDF

Info

Publication number
CN117326985A
CN117326985A CN202311273144.XA CN202311273144A CN117326985A CN 117326985 A CN117326985 A CN 117326985A CN 202311273144 A CN202311273144 A CN 202311273144A CN 117326985 A CN117326985 A CN 117326985A
Authority
CN
China
Prior art keywords
butanol
reaction
ammonia
gas
isophorone
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202311273144.XA
Other languages
Chinese (zh)
Inventor
李方彬
孙学文
易水晗
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sichuan Yuanli Material Technology Co ltd
Original Assignee
Sichuan Yuanli Material Technology Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from CN202211207615.2A external-priority patent/CN116589382A/en
Priority claimed from CN202211208026.6A external-priority patent/CN115433106A/en
Application filed by Sichuan Yuanli Material Technology Co ltd filed Critical Sichuan Yuanli Material Technology Co ltd
Publication of CN117326985A publication Critical patent/CN117326985A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/14—Production of inert gas mixtures; Use of inert gases in general
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/06—Flash distillation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/14—Fractional distillation or use of a fractionation or rectification column
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/34—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping with one or more auxiliary substances
    • B01D3/38—Steam distillation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
    • B01D5/0057—Condensation of vapours; Recovering volatile solvents by condensation in combination with other processes
    • B01D5/006—Condensation of vapours; Recovering volatile solvents by condensation in combination with other processes with evaporation or distillation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C269/00—Preparation of derivatives of carbamic acid, i.e. compounds containing any of the groups, the nitrogen atom not being part of nitro or nitroso groups
    • C07C269/04—Preparation of derivatives of carbamic acid, i.e. compounds containing any of the groups, the nitrogen atom not being part of nitro or nitroso groups from amines with formation of carbamate groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C269/00—Preparation of derivatives of carbamic acid, i.e. compounds containing any of the groups, the nitrogen atom not being part of nitro or nitroso groups
    • C07C269/08—Separation; Purification; Stabilisation; Use of additives
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2601/00—Systems containing only non-condensed rings
    • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
    • C07C2601/14—The ring being saturated

Abstract

The invention relates to the field of IPDI synthesis, and in particular discloses an industrial process for synthesizing isophorone dicarbamic acid n-butyl ester by adopting a urea method, which comprises the following steps of: and (3) taking IPDA, n-butanol, urea and a catalyst to carry out an alkoxycarbonyl reaction of organic amine in a kettle reactor, discharging ammonia gas which is a byproduct of the alkoxycarbonyl reaction along with the evaporated excessive n-butanol and carrier gas, and removing most of ammonia dissolved in the condensed and refluxed liquid phase n-butanol in a rectification mode. Discharging ammonia-containing tail gas containing n-butanol, carrier gas and ammonia components in the reaction process, and obtaining a crude product of isophorone dicarbamic acid n-butyl ester after the reaction is completed; and the target product isophorone dicarbamate n-butyl is obtained by a refining process formed by flash evaporation and falling film evaporation of the isophorone dicarbamate crude product. The synthesis process has the advantages of simple flow, little pollution, high raw material utilization rate and high economic benefit, and is suitable for large-scale industrial production.

Description

Industrialized synthesis process of isophorone dicarbamic acid n-butyl ester
Technical Field
The invention relates to the technical field of IPDI synthesis, in particular to a synthesis process of isophorone dicarbamic acid n-butyl ester which can be industrialized.
Background
Diisocyanate refers to a substance containing two NCO groups, and reacts with polyol to synthesize polyurethane material. The prior isocyanate mainly comprises MDI, TDI, HDI, IPDI, HMDI, XDI, NDI, PPDI, CHDI and other varieties. Of these, MDI and TDI are the two most predominant species at present, accounting for approximately over 85% of the total amount of diisocyanate, while HDI, IPDI and hydrogenated MDI have been increasingly used in recent years due to their excellent weatherability and yellowing resistance.
IPDI (isophorone diisocyanate, CAS No. 4098-71-9) is a preferred starting material for the synthesis of light-stable, weather-resistant polyamino acids, which are high-end products among the isocyanate starting materials. The polyurethane coating is mainly used in the fields of aqueous polyurethane dispersion liquid, anticorrosive paint, UV resin, adhesive, PU resin, printing ink and the like. Meanwhile, the IPDI can also be used in rocket propellant industry.
The production method of IPDI mainly comprises a phosgene method and a carbamate thermal cracking method, and the phosgene method is the main production method of diisocyanate at present. The phosgene method mainly comprises a liquid-phase phosgene method and a gas-phase phosgene method, but the liquid-phase phosgene method has long reaction time, large required solvent quantity, low space-time efficiency of a reactor, more byproducts and relatively lagging; a series of engineering technical problems such as safety, environmental protection and the like in the production process of the gas-phase phosgene method are difficult to solve, the equipment is severely corroded, the requirements on equipment materials are relatively high, the corresponding equipment investment is relatively high, and the obtained isocyanate product contains hydrolytic chlorine, so that the usability of the product is affected. Thus, developed countries have been devoted to develop economical and simple synthetic methods, and thus various methods for synthesizing isocyanates by non-phosgene methods, such as a carbonylation method, a chloroformyl amide thermal decomposition method, a critium rearrangement method, an amine and chloroformyl ester reaction method, a carbamate thermal decomposition method, etc., have been developed, but most of them remain in laboratory stages, and only the carbamate thermal decomposition method has achieved the production of devices abroad. The urea method has the most studied route, is mature and is applied to foreign industries. The urea method isocyanate preparation process comprises two steps, namely, reacting urea, diamine and alcohol to generate the dicarbamate, and performing reheat pyrolysis on the dicarbamate to generate isocyanate and alcohol, wherein the total reaction yield can reach 90%.
The development and production of diisocyanate in China are relatively late, but with the rapid development of society and economy in China, china becomes a global country for producing and consuming diisocyanate. On the other hand, in the field of high-performance special isocyanate, the development of China is very slow, and the consumption demand is increased by more than 15% in year. The aliphatic isocyanate is mainly applied to the fields of automotive finishing paint, rocket propellant, anti-corrosion paint, photo-curing paint, adhesive and the like. Because of the history of the introduction technology, the high-grade paint for industries such as automobiles, high-speed trains, airplanes, ships, luxury buses, wood furniture, buildings and the like in China is fully occupied by foreign products, wherein one of restriction factors is the key raw material aliphatic diisocyanate.
At present, the annual requirements of HDI and IPDI in China are about 9.5 ten thousand tons, the national product requirements are mainly occupied by a few nationwide companies such as winning, de-Gusai and the like, the domestic product requirements are basically all dependent on import, and part of high-end military varieties are limited and sold in China. The aliphatic diisocyanate is produced in China, particularly by adopting a non-phosgene green synthesis technology, is very necessary for promoting the technical progress and industry upgrading of related industries and guaranteeing the industrial safety of important industries in China, has great economic benefit and great social significance, but only De-Gusai and Basv are respectively built with 1 ten thousand tons/year production devices by a non-phosgene method at present.
At present, industrial urea method in China produces IPDU-B (molecular formula is:the invention provides an industrial process for synthesizing isophorone n-butyl dicarbamate by adopting a urea method based on the great significance of IPDI on national economy and industry safety and the realization of laggard domestic production and development, which breaks the technical monopoly of the industrial urea method for synthesizing IPDI in developed countries, not only eliminates the high environmental safety hidden trouble of the phosgene method process from the root, but also strives for the same competitiveness with the phosgene method technology in terms of cost.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide an industrialized synthesis process of isophorone dicarbamate n-butyl to at least achieve the effects of simple process flow, low pollution, high raw material utilization rate, high economic benefit and suitability for large-scale industrialized production.
The aim of the invention is realized by the following technical scheme:
the industrialized synthesis process of isophorone dicarbamic acid n-butyl ester comprises the following steps:
taking IPDA (isophorone diamine, CAS number 2855-13-2), n-butanol, urea and a catalyst, carrying out an alkoxycarbonyl reaction of organic amine (the IPDA is organic amine containing two amino groups) in a kettle test reactor, discharging ammonia gas which is a byproduct of the alkoxycarbonyl reaction along with evaporated excessive n-butanol and carrier gas (the mixed gas phase material is synthetic tail gas), liquefying and refluxing most of the gas phase n-butanol in the synthetic tail gas in a condensing mode, and removing most of ammonia dissolved in the condensed and refluxed liquid phase n-butanol in a rectifying mode (stripping deamination tower), wherein ammonia-containing tail gas containing n-butanol, carrier gas and ammonia components is discharged in the process, and the reaction is completed to obtain a crude product of isophorone n-butyl dicarbamate (IPDU-B);
the target product isophorone dicarbamate n-butyl is obtained by a refining process formed by flash evaporation and falling film evaporation of the isophorone dicarbamate crude product;
it is noted that, in order to make the byproduct ammonia gas be better separated, the carrier gas is directly introduced into the reaction solution of the alkoxycarbonyl reaction, and the carrier gas and the evaporated n-butanol vapor carry out tail gas containing ammonia components, so that the reaction balance moves towards the direction of the target product (rightward), and the reaction degree is more thorough.
The synthesis tail gas is subjected to an n-butanol deamination process to obtain a deamination n-butanol reflux reaction kettle and an ammonia-containing tail gas (main components: ammonia, nitrogen, carbon dioxide and n-butanol) is discharged;
removing ammonia-containing tail gas through ammonium carbamate to obtain ammonia-removed tail gas (main components of ammonia gas, nitrogen gas and residual n-butanol), condensing and recycling part of n-butanol, and blowing out the removed ammonium carbamate through thermal decomposition;
the ammonia carbamate tail gas is subjected to the removal of residual n-butanol to obtain n-butanol and a butanol-removed tail gas (main components: nitrogen and ammonia);
the butanol-removing tail gas is subjected to ammonia component removal treatment to obtain ammonium salt, and the final tail gas (main component: nitrogen) reaching the standard is discharged.
For the n-butanol deamination process:
the deamination of the n-butanol specifically comprises the following steps: the ammonia dissolved in the liquid phase n-butanol condensed and refluxed by the tower top condenser is mostly removed by a rectification mode (stripping deamination tower). The non-condensed gas phase of the tower top condenser is discharged, namely ammonia-containing tail gas which contains a small amount of n-butanol and mainly contains carrier gas and ammonia components;
furthermore, the deaminated n-butanol is returned to the alkoxycarbonyl reaction as a raw material, so that the concentration of byproduct ammonia in a reaction system is greatly reduced while the proportion of the raw materials is maintained, the reaction balance is promoted to move rightwards, the reaction yield is improved, and a large amount of industrial cost is saved.
For the removal process of ammonium carbamate:
notably, are: the trace moisture (about 0.3-0.5%) brought by the urea raw material is hydrolyzed to obtain trace CO under the condition of IPDU synthesis reaction 2 And discharging the reaction tail gas. And CO 2 With ammonia, ammonium carbamate is formed at a lower temperature (this reaction is a reversible reaction, and at a higher temperature it is decomposed into CO 2 And ammonia) ammonium carbamate has a melting point of about 59-60 c, which can block piping and valves, etc. at low process temperatures Duan Xichu.
Further, the materials of the ammonium carbamate to be removed are: after the ammonia-containing tail gas obtained by the process of synthesizing isophorone diamino n-butyl ester by a urea method is subjected to condensation treatment, trace n-butanol in the ammonia-containing tail gas is liquefied, and then trace carbon dioxide in the ammonia-containing tail gas reacts with ammonia components to generate ammonium carbamate powder.
Further, the ammonia-containing tail gas is subjected to condensation treatment, so that trace n-butanol in the ammonia-containing tail gas is liquefied, carbon dioxide reacts with ammonia components to generate ammonium carbamate, and material separation is carried out on ammonium carbamate powder and n-butanol liquid obtained by condensation.
Further, the condensing temperature is 30-60 ℃.
Further, the material separation is as follows: and after the condensation treatment, performing gas-liquid separation on the mixture of the ammonium carbamate and the liquid n-butanol obtained by condensation in a gas-liquid separation mode to obtain ammonia-containing tail gas containing ammonium carbamate powder and liquid-phase n-butanol, and performing gas-solid separation on the ammonia-containing tail gas containing the ammonium carbamate powder to remove solid ammonium carbamate.
Further, the gas-solid separation treatment mode is as follows: introducing the ammonia-containing tail gas into a gas-solid separator;
further, the ammonium carbamate removal process further comprises a regeneration process of the gas-solid separator, and the regeneration process comprises the following steps: after the ammonium carbamate is enriched in the gas-solid separator, the ammonium carbamate enriched in the gas-solid separator is blown by high-temperature nitrogen to decompose the ammonium carbamate solid into an ammonia component and carbon dioxide so as to regenerate the gas-solid separator.
It is noted that two gas-solid separators need to be arranged for switching, one of the gas-solid separators needs to be switched out of the process after working for a certain period, and high-temperature inert gas is used for back blowing regeneration, and the other gas-solid separator is switched to work at the moment.
For the removal process of residual n-butanol:
notably, the formation process of the residual n-butanol is as follows: in the process for synthesizing isophorone diamino n-butyl ester by the urea method, most n-butanol is removed by condensing in an overhead condenser of an n-butanol deamination process, and then n-butanol is further removed by condensing in an ammonium carbamate removal process, but the rest trace n-butanol cannot be condensed;
further, the method for removing the residual n-butanol specifically comprises the following steps: cooling the ammonia carbamate tail gas to 15-25 ℃, and then adsorbing n-butanol in the tail gas by using an adsorbent (adsorption step);
further, the adsorbent comprises: at least one of molecular sieve, activated carbon and polymer adsorption resin;
the adsorbent can selectively adsorb n-butanol and is not substantially adsorbed to ammonia; preferably, the special adsorbent for Haima nano HDV536 has granularity (0.6-1.25 mm) > 95%, specific surface area 1400 square meter/g, pore volume 0.90ml/g and pore diameter
The adsorbent is adsorbed to obtain the butanol-removing tail gas, and the content of n-butanol in the butanol-removing tail gas is less than 12mg/m 3 。
Further, the method for removing the residual n-butanol further comprises the following steps (desorption step): desorbing and regenerating the adsorbent by adopting high-temperature nitrogen to obtain regenerated adsorbent and regenerated tail gas, and condensing the regenerated tail gas to obtain liquid n-butanol and inert gas containing trace n-butanol;
the temperature of the high-temperature inert gas is 140-160 ℃;
the adsorbent is adsorbed to obtain the butanol-removing tail gas, and the content of n-butanol in the butanol-removing tail gas is less than 12mg/m 3 ；
The method for removing the residual n-butanol is provided with at least two sets of adsorption units, and adsorption and desorption alternate operations are performed in turn.
Further, n-butanol obtained in the ammonium carbamate removal and residual n-butanol removal steps is collected and used as a raw material for a reaction of a subsequent batch.
For ammonia component removal treatment:
further, the ammonia component removal treatment is as follows: and (3) introducing the butanol-removed tail gas into an acid solution to enable an ammonia component in the butanol-removed tail gas to react with the acid to generate ammonium salt.
Further, the molar ratio of the IPDA, the n-butanol, the urea and the catalyst is 1:4-10:2-2.5:0.001-0.012; the reaction temperature of the alkoxycarbonyl reaction is 200-250 ℃, and the reaction pressure is 0.9-2.3MPa.
Preferably, the molar ratio of IPDA, n-butanol, urea and the catalyst is 1:5-8:2-2.3:0.004-0.01; the reaction temperature is preferably 215-235 deg.c and the reaction pressure is 1.2-1.5MPa.
Further, the catalyst comprises: zinc acetate, manganese acetate, zirconium acetate, cobalt acetate; preferably, the catalyst is zirconium acetate.
Further, the carrier gas is nitrogen.
Furthermore, the invention has been built into an industrial plant for annual production of 100t and has completed industrial verification, and an industrial plant for annual production of 2kt is being built.
The main equipment of the industrial device for annual production of 2kt to be built comprises: and (3) a reaction kettle: phi 1400 x 4253,5.4m 3 Stripping deamination tower: Φ500x5000 (overhead condenser a=20m) 2 ) Flash evaporator Φ700×1600, falling film evaporator Φ1000×2500; an ammonia-containing tail gas condenser: a=5.4m2, gas-liquid separator: v=0.61 m 3 Φ700×1300 (straight tube); gas-solid separator: v=0.61 m 3 Φ700×1300 (straight tube); n-butanol adsorption tower: 1800mm diameter, 2000mm height, 3 stations, operating conditions: 30-150 ℃ (regeneration 150 ℃), micro positive pressure.
The main equipment of the industrial device for annual production of 100t, which is built by the invention, comprises: and (3) a reaction kettle: Φ650×800, 300L, stripping deamination column: phi 273 x 5000 (deamination tower top condenser a=6m) 2 ) Falling film evaporator phi 300 multiplied by 1200; an ammonia-containing tail gas condenser: a=2.2m 2 Gas-liquid separator: v=0.10m 3 Φ400×800 (straight tube); gas-solid separator: v=0.61 m3 Φ700×1300 (straight tube); n-butanol adsorption tower: diameter 300mm, height 1200mm,3 stations, operating conditions: 30-150 ℃ (regeneration 150 ℃), micro positive pressure.
The beneficial effects of the invention are as follows:
1. the synthesis process has simple flow, less pollution, high raw material utilization rate and high economic benefit, and the carrier gas and the n-butyl alcohol steam bring out the by-product ammonia, thereby being beneficial to promoting the rapid and efficient synthesis reaction, and the yield of the isophorone dicarbamic acid n-butyl ester is more than 98 percent through the strengthening design of various processes, thereby being suitable for large-scale industrial production.
2. The ammonium carbamate treatment process is simple, manual operation is not needed, the removal effect is good, and the continuous and smooth operation of the isophorone dicarbamate synthesis tail gas treatment process can be ensured.
3. The method of the invention treats the isophorone dicarbamic acid n-butyl tail gas, and the n-butanol content in the adsorption tail gas is far lower than the industrial emission standard (12 mg/m) 3 ) Has no secondary pollution and high system safety, and can separate trace n-butanol from nitrogenThe desorption tail gas after the process is circulated to the front end of the desorption tower for adsorption and reutilization, secondary pollution is avoided, the system safety is high, the service life of the adsorbent is as long as 3-5 years, and the n-butanol adsorption rate is high (more than 99%).
Drawings
FIG. 1 is a process flow diagram of the present invention;
FIG. 2 is a flow chart showing the process of the present invention for the removal of carbamic acid;
FIG. 3 is a flow chart showing the process for removing residual n-butanol according to the present invention.
Detailed Description
The technical solution of the present invention will be described in further detail with reference to the accompanying drawings, but the scope of the present invention is not limited to the following description.
1. Equipment, raw materials, process flow and detection method for synthesizing IPDU-B by laboratory and industrial urea method.
Equipment used in laboratory urea process:
and (3) a reaction kettle: 10L; outlet condenser: Φ50X100;
raw material preparation by a laboratory urea method:
urea: GB/T2440-2001 industrial superior, total nitrogen (N) (on a dry basis) is more than or equal to 46.5%;
n-butanol: GB/T6027-1998 superior products with the main content more than or equal to 99.5 percent;
IPDA: the main content is more than or equal to 99.5 percent;
catalyst (zirconium acetate): the purity was 99.0%.
The specific method for synthesizing isophorone dicarbamate by using the urea method in the laboratory comprises the following steps:
IPDA, urea, n-butanol and a catalyst are added into a 10L stainless steel reaction kettle, and the synthesis reaction is carried out for 2 hours under the condition of the pressure of 1.50Mpa.G at 225 ℃ to generate isophorone-n-butyl dicarbamate, and simultaneously ammonia gas is discharged. Ammonia escapes through the evaporation of the supplemental nitrogen and the n-butanol, the n-butanol is condensed to automatically flow back to the reaction kettle shape, and the tail gas is absorbed by dilute sulfuric acid. After the synthesis reaction is finished, the reaction kettle is naturally cooled, and then a vacuum pump and an electric heater are started to evaporate the residual n-butanol in the kettle.
Equipment used in the industrialized urea method:
and (3) a reaction kettle: Φ650×800, 300L, stripping deamination column: phi 273 x 3000 (deamination tower top condenser a=6m) 2 ) Falling film evaporator phi 300 multiplied by 1200;
an ammonia-containing tail gas condenser: a=2.2m 2 Gas-liquid separator: v=0.10m 3 Φ400×800 (straight tube);
gas-solid separator: v=0.61 m3 Φ700×1300 (straight tube);
n-butanol adsorption tower: diameter 300mm, height 1200mm,3 stations, operating conditions: 30-150 ℃ (regeneration 150 ℃), micro positive pressure.
Raw material preparation:
urea: GB/T2440-2001 industrial high-grade product with actual purity of 99.6%;
n-butanol: GB/T6027-1998 superior products with actual main content of 99.8%;
IPDA: purity 99.5%;
catalyst (zirconium acetate): the purity was 99.0%.
The specific method for synthesizing isophorone dicarbamic acid n-butyl ester by the industrialized urea method comprises the following steps:
adding liquid raw material n-butanol (excessive), raw material IPDA, solid raw material urea (slightly excessive) and liquid catalyst zirconium acetate into a 300L stainless steel reaction kettle, sealing the reaction kettle after the addition, replacing air in the kettle with nitrogen, and introducing 4.5Nm according to the nitrogen 3 The temperature is raised to 225 ℃ and the synthesis reaction is carried out for 2 hours under the condition of the pressure of 1.50 Mpa.G. After the reaction is finished, decompressing and flashing part of n-butyl alcohol of the bottom product of the kettle, circularly dealcoholizing for 2 hours by a falling film evaporator under the conditions of 200 ℃ and vacuum degree of-0.090 MPa, and removing unreacted n-butyl alcohol and intermediate product n-butyl carbamate to obtain the intermediate product isophorone dicarbamate n-butyl ester.
In the reaction process, gas-phase materials (namely synthetic tail gas) at the outlet of the reaction kettle sequentially pass through a stripping deamination tower and a condenser positioned at the top of the stripping deamination tower to obtain gas-phase materials and liquid-phase materials, wherein the gas-phase materials are ammonia-containing tail gas which contains a small amount of n-butanol and mainly contains carrier gas and ammonia components. The liquid phase material is most of n-butanol condensed from the synthesis tail gas, the liquid phase material is refluxed to the top of the stripping deamination tower, most of ammonia dissolved in the liquid phase material is removed by the stripping deamination tower, and finally the n-butanol after deamination returns to the reaction kettle.
Introducing high-temperature ammonia-containing tail gas into a condenser, cooling to 59 ℃, liquefying most of n-butanol contained in the ammonia-containing tail gas at the moment, solidifying ammonium carbamate, wherein the tail gas is a mixture of nitrogen, ammonia, liquid n-butanol and ammonium carbamate solids, introducing the tail gas into a gas-liquid separator to remove n-butanol, blowing the nitrogen, the ammonia and the ammonium carbamate into the gas-solid separator, and filtering and adsorbing the ammonium carbamate by the gas-solid separator to obtain the ammonia-removed tail gas containing residual n-butanol.
And (3) introducing the ammonia carbamate tail gas containing the residual n-butanol into a precooler for cooling, keeping the outlet temperature at 20 ℃, pumping and pressurizing the cooled tail gas by a fan, and introducing the tail gas into an adsorption tower filled with the nano adsorbent. And introducing the absorbed tail gas into a sulfuric acid absorber to obtain ammonium salt and final tail gas.
The nano adsorbent is special for the Haima nano HDV536, selectively adsorbs n-butanol and does not basically adsorb ammonia. Particle size (0.6-1.25 mm) > 95%, specific surface area 1400 square meter/g, pore volume 0.90ml/g, pore diameter
The detection method is shown in Table 1:
TABLE 1
Sequence number Analysis item Detection method
1 IPDU-B content GC-FID
2 N-butanol content GC-FID
3 Ammonia content GC-FID
5 Ammonium carbamate content GC-FID (CO measurement) 2 Peak (Peak)
2. Screening the synthesis temperature and time in the process of synthesizing isophorone dicarbamic acid n-butyl ester by using a urea method in a laboratory:
the synthesis temperature gradient of 200 ℃,215 ℃, 225 ℃, 235 ℃, 250 ℃ was set, and the method for synthesizing IPDU-B by referring to a laboratory urea method (IPDA: 1289g (7.57 mol), n-butanol: 4487g (60.6 mol), urea: 1000g (16.5 mol)) was divided into 5 groups of experiments according to the temperature gradient to synthesize isophorone dicarbamate, each group was then detected at reaction times of 1.5, 2, 3, 4, 5 hours, respectively, the content of isophorone dicarbamate (IPDU-B) was calculated, and the yield was calculated, and the statistical yield was shown in Table 2.
TABLE 2
As is clear from Table 2, the yield of IPDU-B increases with increasing reaction temperature, but the reaction time continues to increase after the reaction time exceeds 2 hours, and the synthesis rate of IPDU-B becomes slower and the synthesis cost increases exponentially, so that the reaction time is preferably selected to be about 2 hours in view of economic efficiency. When the reaction temperature is 200-250 ℃ and the synthesis time is 2 hours, the yield of the IPDU-B is above 60 percent. When the reaction temperature is 215-250 ℃, the yield of IPDU-B is over 90%, the increase of the temperature yield is not obvious, and the synthesis temperature is selected to be the optimal reaction temperature from 200-250 and 215-235 is the optimal reaction temperature from the consideration of economic benefit.
3. Screening of synthesis pressure in a process for synthesizing isophorone dicarbamate by a urea method in a laboratory:
synthetic pressure gradients of 0.9, 1.1, 1.2, 1.3, 1.35, 1.4, 1.5, 1.8 and 2.3MPa were set, and according to the method for synthesizing IPDU-B by the laboratory urea method (IPDA: 1289g (7.57 mol), n-butanol: 4487g (60.6 mol) and urea: 1000g (16.5 mol)), isophorone n-butyl dicarbamate was synthesized by dividing the pressure gradient into 9 groups of experiments, and the content of isophorone n-butyl dicarbamate (IPDU-B) was detected and the yield was calculated, and the statistical yield was found in Table 3.
TABLE 3 Table 3
Experiment number Reaction pressure (MPa) IPDU-B yield (%)
1 0.9 91.2
2 1.1 94.4
3 1.2 96.2
4 1.3 97.5
5 1.35 98.5
6 1.4 98.1
7 1.5 98.3
8 1.8 98.2
9 2.3 98.3
As is clear from Table 3, when the reaction pressure is more than 0.9MPa, the yield of IPDU-B is higher than 90%, and the yield is gradually increased with the gradual increase of the reaction pressure, but when the increase is smaller and smaller, the reaction pressure of 0.9-2.3MPa is preferable and the reaction pressure of 1.2-1.5MPa is preferable from the viewpoint of economic efficiency.
4. Screening the dosage of n-butanol in the process of synthesizing isophorone dicarbamic acid n-butyl ester by using a urea method in a laboratory:
n-butanol gradients of 4, 5, 6, 7, 8, 9 and 10 n-butanol/IPDA (mol) were set, and according to the method for synthesizing IPDA-B by the laboratory urea method (IPDA: 1289g (7.57 mol), n-butanol: 2244 to 5609g (30.3 to 75.7 mol), urea: 1000g (16.5 mol)), n-butyl isophorone-dicarbamate was synthesized by dividing the n-butanol gradient into 7 groups of experiments, and the content of n-butyl isophorone-dicarbamate (IPDA-B) was detected by GC-FID, and the yield was calculated, and the statistical yield data are shown in Table 4.
TABLE 4 Table 4
Experiment number n-butanol/IPDA (mol) IPDU-B yield (%)
1 4 75.6
2 5 97.2
3 6 97.5
4 7 97.8
5 8 98.5
6 9 97.9
7 10 98.1
Note that: n-butanol/IPDA (mol) means the molar ratio of n-butanol to IPDA.
As can be seen from Table 4, when the molar ratio of n-butanol to IPDA used was more than 4, the yield of IPDU-B was 75% or more, at a preferable level, and increased as the amount of n-butanol added was increased, but when the molar ratio was more than 5, the yield was almost maintained, so that n-butanol was selected for economic efficiency: ipda=4-10 is the preferred n-butanol usage, n-butanol: ipda=5-8 is the optimal n-butanol usage.
5. Screening the urea dosage in the process of synthesizing isophorone dicarbamic acid n-butyl ester by a laboratory urea method:
the urea usage gradients of 2, 2.05, 2.1, 2.2, 2.3 and 2.5 were set up, and according to the method for synthesizing IPDA-B by the laboratory urea method (IPDA: 1289g (7.57 mol), n-butanol: 4487g (60.6 mol), urea: 909-1147 g (15.0-18.9 mol)), the isophorone-n-butyl dicarbamate was synthesized according to the urea usage gradient by 6 groups of experiments, and the content of isophorone-n-butyl dicarbamate (IPDA-B) was detected by GC-FID, and the yield was calculated, and the statistical yield data are shown in Table 5.
TABLE 5
Experiment number Urea/IPDA (mol) IPDU-B yield (%)
1 2 83.6
2 2.05 91.2
3 2.1 96.2
4 2.2 97.5
5 2.3 97.6
6 2.5 97.6
Note that: urea/IPDA (mol) means the molar ratio of urea to IPDA.
As can be seen from Table 5, when the molar ratio of urea/n-butanol is greater than 2, the yield of IPDU-B is greater than 80%, at a better level, and increases continuously with increasing urea addition, but when the molar ratio is greater than 2.2, the yield remains almost unchanged, and from the economic standpoint, urea is chosen: n-butanol=2-2.5 is the preferred urea dosage, urea: n-butanol=2.2-2.5 is the optimal urea dosage.
6. The industrial urea method for verifying the effect of synthesizing the IPDU-B product comprises the following steps:
158.5kg (2.14 koml) of liquid raw material n-butanol, 45.5kg (0.27 kmol) of raw material IPDA, 35.5kg (0.57 kmol) of solid raw material urea and 318g (0.97 mol) of liquid catalyst zirconium acetate are added into a 300L stainless steel reaction kettle, the reaction kettle is closed after the addition, the air in the kettle is replaced by nitrogen, and then 4.5Nm of nitrogen is introduced according to the nitrogen introducing amount 3 The temperature is raised to 225 ℃ and the synthesis reaction is carried out for 2 hours under the condition of the pressure of 1.50 Mpa.G. After the reaction is finished, decompressing and flashing part of n-butyl alcohol, circularly dealcoholizing for 2 hours by a falling film evaporator under the conditions of 200 ℃ and vacuum degree of-0.090 MPa, removing unreacted n-butyl alcohol and intermediate product n-butyl carbamate to obtain 97.5kg of intermediate product isophorone diamino n-butyl carbamate and the product yield is 98.4% (the detection method is GC-FID).
The above-mentioned verification was carried out again by changing the amount of the raw material, 101.6kg (1.37 kmol) of n-butanol, 45.5kg (0.27 kmol) of IPDA as the raw material, 37.0kg (0.61 kmol) of urea as the solid raw material, and 318g (0.97 mol) of zirconium acetate as the liquid catalyst. 97.2kg of isophorone dicarbamate as an intermediate product is obtained, and the product yield is 98.1% (the detection method is GC-FID).
It can be seen that the yield of industrial production IPDU-B is greater than 98%, which shows that the feasibility of the industrial process and the industrial parameters are verified.
7. The treatment effect of industrial urea method for synthesizing IPDU-B waste gas is as follows:
the industrial urea process was used to synthesize IPDA-B (IPDA: 45.5kg (0.27 kmol), n-butanol: 158.5kg (2.14 kmol), urea: 35.5kg (0.57 kmol), zirconium acetate 400g (1.22 mol)), and process nitrogen was used as a carrier gas. Introducing high-temperature ammonia-containing tail gas into a condenser, cooling to 59 ℃, liquefying n-butanol at the moment, solidifying ammonium carbamate, introducing the tail gas into a gas-liquid separator again to remove n-butanol, introducing nitrogen, ammonia and ammonium carbamate into the gas-solid separator, filtering and adsorbing the ammonium carbamate by the gas-solid separator to obtain the ammonia-free tail gas containing residual n-butanol, and blowing out the enriched ammonium carbamate in the gas-solid separator by high-temperature nitrogen to decompose the ammonium carbamate solid into ammonia components and carbon dioxide so as to regenerate the gas-solid separator.
And (3) introducing the ammonium carbamate tail gas containing the residual n-butanol into a precooler for cooling, keeping the outlet temperature at 20 ℃, pumping and pressurizing the cooled tail gas by a fan, and introducing the tail gas into an adsorption tower filled with a nano adsorbent to obtain the butanol-removed tail gas. And introducing the adsorbed butanol-removed tail gas into a sulfuric acid absorber to obtain ammonium salt and final tail gas.
And stopping adsorption when the adsorption tower reaches the cycle time (three adsorption towers and one adsorption tower are involved, simultaneously, the other two adsorption towers are used for desorption, the adsorption and desorption processes are alternately carried out through switching between valves, the adsorption tower is automatically switched to the desorption process when reaching the penetration point), the adsorbent is desorbed and regenerated by adopting nitrogen at 150 ℃, the ammonia containing n-butanol after desorption is separated by low-temperature freezing water condensation, the separated liquid phase n-butanol is collected to an n-butanol recovery tank, and the gas phase containing trace n-butanol and nitrogen returns to the front end of the adsorption tower and is incorporated into the ammonia-deamination tail gas to remove the trace n-butanol through the adsorption tower.
The contents of the components in the ammonia-containing tail gas before condensation, the ammonia-containing tail gas after condensation, the deaminated ammonium tail gas and the final tail gas were measured, and the results are shown in table 6.
TABLE 6
Ammonia (%) N-butanol (%) Ammonium carbamate (%) Nitrogen (%)
Ammonia-containing tail gas before condensation 46.74 4.63 0.60 48.04
Ammonia-containing tail gas after condensation 48.43 1.18 0.62 49.77
Tail gas of deaminated ammonium formate 48.74 1.20 0.05 50.01
Butanol removing tail gas 48.96 0.001 0.05 50.989
Final tail gas 0.003 Not detected Not detected 99.997
As shown in Table 6, the high temperature ammonia-containing tail gas discharged from the synthesis of isophorone diamino n-butyl ester contains 0.62% of ammonium carbamate, and after the process of removing ammonium carbamate, the content of ammonium carbamate in the tail gas is only 0.05%, and the ammonium carbamate removal rate reaches 92%, which indicates that the process of removing ammonium carbamate can effectively remove ammonium carbamate in the process of synthesizing isophorone diamino n-butyl ester by a urea method, and can prevent pipelines and valves of industrial equipment from being blocked by ammonium carbamate. The ammonia content in the butanol-removing tail gas is 48.96%, and the ammonia content in the final tail gas is only 0.003%, which indicates that the ammonia in the tail gas can be effectively removed by the deamination process. The content of n-butanol in the deaminated ammonium formate tail gas is 1.20%, and no n-butanol is detected in the final tail gas, which indicates that the whole tail gas removal process can effectively remove n-butanol in the tail gas.
8. The intermediate product isophorone dicarbamate is synthesized into IPDI through a thermal cracking process, and the thermal cracking process is preferably the following scheme:
(1) Raw materials
N-butyl isophorone dicarbamate (IPDU-B) component: the internal control index is more than or equal to 99.0 percent (99.38 percent of IPDU-B, 0.46 percent of catalyst for synthesizing the IPDU-B and the other 0.16 percent);
thermal cracking reaction catalyst: zinc picolinate, chromium picolinate, MOF-5, zinc oxide, bismuth trioxide, ionic liquid zinc, zinc chloride, zinc acetate, zinc acrylate, zinc isooctanoate;
solvent: naphthenic oil KN4010, naphthenic oil KN4006, naphthenic oil KN4016, trioctyl trimellitate and trionyl trimellitate.
(2) Detection method
The following table is provided:
(3) Industrial thermal cracking reactor
IPDU-B feed pump: q=2m 3 H, h=14m; 1# cracker：A＝30m 2 The method comprises the steps of carrying out a first treatment on the surface of the 1# pyrolysis circulation pump: q=5m 3 H, h=14m; 1# high polymer drainage pump: q=2m 3 H, h=14m; 2# cracker: a=25m 2 The method comprises the steps of carrying out a first treatment on the surface of the 2# pyrolysis circulation pump: q=5m 3 H, h=14m; 2# high polymer drainage pump: q=2m 3 /h，H＝14m。
(4) Industrial thermal cracking reaction flow
The thermal decomposition raw material IPDU-B, solvent and catalyst enter a No. 1 rotary scraping plate thermal decomposition reactor, a liquid film is forcedly formed on the inner wall of the reactor by the rotary scraping plate, and the thermal decomposition reaction is carried out by heating the inner wall of the reactor. Under the vacuum condition, the thermal decomposition products are rapidly evaporated to realize rapid separation from the reaction raw materials, thereby greatly reducing the generation of side reactions. The gas phase material (gas phase material I, reaction product) at the outlet of the reactor enters a rectifying unit. The material (mainly single side) at the bottom of the rectifying tower enters a No. 2 rotary scraping plate thermal decomposition reactor for thermal decomposition reaction, and the gas-phase material (gas-phase material III, reaction product) at the outlet of the reactor and the gas-phase material I are combined and enter a rectifying unit. The bottoms of the two reactors are provided with a circulating tank and a circulating pump, and the solvent and the catalyst circulate.
(5) Solvent recovery device
Scraper evaporator: heat exchange area s=12m 2
(6) Method for recovering solvent
It should be emphasized that this part is to treat the heavy component materials after the primary separation of the circulating liquid discharged from the bottoms of the two rotary scraper thermal decomposition reactors in the industrial thermal cracking reaction flow of (4).
Heavy component materials generated by the pyrolysis reaction of isophorone dicarbamate are pumped to the top of a scraper evaporator, a liquid film is forcedly formed on the inner wall of the evaporator through a rotary scraper, the liquid film is heated through the inner wall of the evaporator, the vapor phase product and the heavy component are obtained through evaporation under the vacuum condition, and the vapor phase product is condensed by a condenser to obtain the recovered solvent. Reaction conditions for heating evaporation: the temperature is 280 ℃, and the reaction pressure is-0.096 to-0.098 MPa.
(7) Reaction equipment for rectification
Light component removal column (rectifying column): phi 1200X 24604, filler height 3888/3888/3888/3240mm
Product column (rectifying column): phi 900X 24348 and packing height 3096/3096/4128/4128mm
And (3) a condenser: light component removing tower top condenser phi 1200 x 2000, heat exchange area 80m 2 The method comprises the steps of carrying out a first treatment on the surface of the Product tower top condenser phi 1000 multiplied by 2000, heat exchange area 90m 2
Reboiler: the reboiler phi at the bottom of the light component removal tower is 1100 multiplied by 2500, and the heat exchange area is 94.5m 2 The method comprises the steps of carrying out a first treatment on the surface of the The reboiler at the bottom of the product tower is phi 1400 multiplied by 3000, and the heat exchange area is 190m 2
And (3) a circulating pump: light component removal tower bottom circulating pump Q=10.8m 3 H= 40m Zone2 EEx dII BT4, product bottom circulation pump q=18m 3 H＝40m Zone2 EEx dII BT4
Auxiliary system: the heat conduction oil system provides a required heat source, the circulating water system and the chilled water system provide refrigerants, the nitrogen system provides nitrogen for the start-stop system to replace, and the vacuum system provides vacuum conditions required by the device
And (3) a control system: the process operation control adopts a DCS system and is provided with a Safety Interlock (SIS) system
(8) Reaction scheme of rectification
It is emphasized that this section belongs to the specific explanation of the rectification unit in the industrial thermal cracking reaction scheme of (4).
The crude product of the gas-phase IPDI (gas-phase material I and gas-phase material III) enters the light component removal tower bottom (first rectifying tower) from the thermal decomposition unit, n-butanol is extracted from the tower top, IPDI rich liquid is extracted from the side line in the middle of the tower, and the material in the tower bottom is circularly thermally decomposed (second thermal decomposition reaction) by the thermal decomposition unit. The IPDI rich liquid extracted from the side line of the light component removal tower is pumped into a product tower (a second rectifying tower), a small amount of n-butanol and IPDI are extracted from the top of the product tower, the IPDI product is extracted from the side line, and the material in the tower bottom (liquid phase material II) is subjected to cyclic thermal decomposition (a second thermal decomposition reaction) by a thermal decomposition unit.
Continuous synthesis of IPDI is carried out according to the industrialized routes (4), (6) and (8), and the control condition is the optimal experimental condition, namely, the operation pressure of the first thermal decomposition is controlled to be-0.094 Mpa, the operation temperature is 240 ℃, the operation pressure of the second thermal decomposition is controlled to be-0.094 Mpa, and the operation temperature is 245 ℃. The operating conditions for controlling the light ends removal column are: 11mbar at the top of the tower, 24mbar at the bottom of the tower, 199.7 ℃ at the bottom of the tower, 25 ℃ at the top of the tower and 160.8 ℃ at the side line temperature; the operating conditions of the product column were: 11mbar at the top of the column, 24mbar at the bottom of the column, 194℃at the top of the column, 40℃at the top of the column and 158.3℃at the side line. After the system is running stably, the statistics of the raw material feeding amount, the obtained product components and the yield corresponding to each step are listed as follows:
/>
/>
note that: the process is continuously carried out, and a gas phase material I and a gas phase material III are produced by different thermal cracking reactors at the same time and are mixed together to enter a first rectifying tower; IPDU feedstock impurities: catalyst for synthesizing IPDU-B0.46% and other impurities 0.16%.
The foregoing is merely a preferred embodiment of the invention, and it is to be understood that the invention is not limited to the form disclosed herein but is not to be construed as excluding other embodiments, but is capable of numerous other combinations, modifications and environments and is capable of modifications within the scope of the inventive concept, either as taught or as a matter of routine skill or knowledge in the relevant art. And that modifications and variations which do not depart from the spirit and scope of the invention are intended to be within the scope of the appended claims.

Claims (6)

1. The industrialized synthesis process of isophorone dicarbamate is characterized by comprising the following steps:
taking IPDA, n-butanol, urea and a catalyst to carry out an alkoxycarbonyl reaction of organic amine, introducing carrier gas in the process of the alkoxycarbonyl reaction to separate byproduct ammonia, discharging synthesis tail gas containing ammonia components in the reaction process, and obtaining a crude product of isophorone dicarbamate n-butyl after the reaction is completed;
taking IPDA, n-butanol, urea and a catalyst to carry out an alkoxycarbonyl reaction of organic amine in a kettle reactor, discharging ammonia gas which is a byproduct of the alkoxycarbonyl reaction along with evaporated excessive n-butanol and carrier gas, liquefying and refluxing most of gas-phase n-butanol in a condensing mode, removing most of ammonia dissolved in the condensed and refluxed liquid-phase n-butanol in a rectifying mode, discharging ammonia-containing tail gas containing n-butanol, carrier gas and ammonia components in the process, and obtaining a crude product of isophorone n-butyl dicarbamate after the reaction is completed;
flash evaporation and falling film evaporation are carried out on the isophorone dicarbamate crude product to obtain a target product isophorone dicarbamate;
the molar ratio of IPDA, n-butanol, urea and the catalyst is 1:4-10:2-2.5:0.001-0.012;
the reaction temperature of the alkoxycarbonyl reaction is 200-250 ℃, and the reaction pressure is 0.9-2.3MPa.
2. The synthesis process according to claim 1, wherein: and (3) deaminizing the synthesis tail gas by adopting an n-butanol deamination process to obtain deaminated n-butanol, refluxing the reaction kettle and discharging ammonia-containing tail gas.
3. The synthesis process according to claim 2, characterized in that: the n-butanol deamination process comprises: and most of ammonia dissolved in the condensed and refluxed liquid-phase n-butanol is removed by a rectification mode, and the uncondensed gas phase is discharged, so that the ammonia-containing tail gas containing a small amount of n-butanol, carrier gas and ammonia group is obtained.
4. A synthesis process according to claim 3, wherein: the deaminated n-butanol is returned as a starting material to the alkoxycarbonyl reaction.
5. The synthesis process according to claim 1, wherein: the catalyst comprises at least one of sodium methoxide, zinc acetate, manganese acetate, zirconium acetate and cobalt acetate.
6. The synthesis process according to claim 1, wherein: the carrier gas is nitrogen.
CN202311273144.XA 2022-09-30 2023-09-28 Industrialized synthesis process of isophorone dicarbamic acid n-butyl ester Pending CN117326985A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN2022112076152 2022-09-30
CN202211207615.2A CN116589382A (en) 2022-09-30 2022-09-30 Industrial IPDI synthesis method
CN202211208026.6A CN115433106A (en) 2022-09-30 2022-09-30 Industrialized synthesis process of isophorone diamino n-butyl formate
CN2022112080266 2022-09-30

Publications (1)

Publication Number Publication Date
CN117326985A true CN117326985A (en) 2024-01-02

Family

ID=89292559

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311273144.XA Pending CN117326985A (en) 2022-09-30 2023-09-28 Industrialized synthesis process of isophorone dicarbamic acid n-butyl ester

Country Status (1)

Country Link
CN (1) CN117326985A (en)

Similar Documents

Publication Publication Date Title
CN101062905B (en) Process for the production of isocyanates
CN101514172B (en) Method for making isocyanates
CA2951165C (en) Method and device system for producing dimethyl oxalate through medium and high-pressure carbonylation of industrial synthesis gas and producing ethylene glycol through dimethyl oxalate hydrogenation
TWI471295B (en) Process for the preparation of isocyanates
CN101605724B (en) A method for recovery of high purity carbon dioxide
CN116589382A (en) Industrial IPDI synthesis method
US4053507A (en) Method of recovering unreacted materials and heat in urea synthesis
CN1123790A (en) A process for producing aromatic amines
JP7268017B2 (en) Method for producing ethyleneamine
CN103408428A (en) Process for producing dimethyl carbonate from industrial synthetic gas
CN102285651B (en) Purification and recycling method of CO in phosgene synthesis unit tail gas
CN100429194C (en) Method for utilizing reaction heat in process of producing methane chloride and purifying mixture
EP3233792A1 (en) Process for urea production
RU2324674C1 (en) Method of production of methanol
CN1554643A (en) Method and apparatus for improving industrial producing urea
CN113336618A (en) Device and method for improving acetylene purity in fixed bed vinyl acetate production system
CN117326985A (en) Industrialized synthesis process of isophorone dicarbamic acid n-butyl ester
CN117342984A (en) Method for removing residual n-butanol contained in tail gas in process of synthesizing isophorone dicarbamate by urea method
CN117326983A (en) Method for removing ammonium carbamate in process of synthesizing isophorone dicarbamate n-butyl ester by urea method
CN117326982A (en) Industrial process for synthesizing isophorone dicarbamic acid n-butyl ester by urea method
CN117326984A (en) Catalyst for synthesizing isophorone dicarbamic acid n-butyl ester technology by urea method
CN1058704C (en) Method for prepn. of urea by carbon dioxide stripping method
CN203411491U (en) Process system for producing dimethyl carbonate from industrial synthesis gas
US10364214B1 (en) Method for producing isocyanates
CN115779626A (en) Method for removing residual n-butanol contained in tail gas in process of synthesizing isophorone diamino acid n-butyl ester by urea 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