CA1125774A - Process for the continuous manufacture of trioxan - Google Patents
Process for the continuous manufacture of trioxanInfo
- Publication number
- CA1125774A CA1125774A CA341,491A CA341491A CA1125774A CA 1125774 A CA1125774 A CA 1125774A CA 341491 A CA341491 A CA 341491A CA 1125774 A CA1125774 A CA 1125774A
- Authority
- CA
- Canada
- Prior art keywords
- trioxan
- evaporator
- reactor
- vapor
- formaldehyde
- 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.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D323/00—Heterocyclic compounds containing more than two oxygen atoms as the only ring hetero atoms
- C07D323/04—Six-membered rings
- C07D323/06—Trioxane
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Heterocyclic Compounds That Contain Two Or More Ring Oxygen Atoms (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
Abstract
PROCESS FOR THE CONTINUOUS MANUFACTURE OF TRIOXAN
Abstract of the disclosure:
The invention provides a process for the continuous manu-facture of trioxan, optionally together with cyclic formals, from aqueous formaldehyde solutions in a circulation reactor with evaporator, the vapor amount leaving the system being in the range of from 0.1 to 4 %. The process of the invention allows to attain especially high space/time yields.
Abstract of the disclosure:
The invention provides a process for the continuous manu-facture of trioxan, optionally together with cyclic formals, from aqueous formaldehyde solutions in a circulation reactor with evaporator, the vapor amount leaving the system being in the range of from 0.1 to 4 %. The process of the invention allows to attain especially high space/time yields.
Description
7'~
- 2 - HOE 78/F 266 The manufacture of trioxan from aqueous formaldehyde is described in the literature (see Walker, Formaldehyde, Reinhold Publ., New York, 3rd ed., 1964, pp. 198/199).
The trioxan formed at elevated temperatures in the presence of acidic catalysts is separated from the reaction mixture by distillation. Generally, the synthesis vapor containing trioxan, water and formaldehyde as well as by-products of the synthesis is rectified either according to U.S.
Patent No. 2 304 080 in a rectifying column mounted onto the reactor, or according to British Patent No. 1 012 372 in a column provided with rectifier and discharge section.
The fraction rich in trioxan so obtained is further worked up by extraction and/or another known separation process.
It is known that the time yields (g of trioxan per kg of formaldehyde and hour) of trioxan synthesis are low.
According to German Patent No. 1 135 491, for example, a time yield of 152 g of trioxan per kg of formaldehyde and hour is attained by simple distillation of the reaction mixture from the reaction vessel. The low time yields cause necessarily long residence times in the manufacture of trioxan from aqueous formaldehyde solutions. Moreover, large reaction volumes are required in order to attain industrially satisfactory space/time yields (g of trioxan per liter of reaction volume and time).
In order to increase the space/time yields of trioxan synthesis, it has been proposed to disturb substantially the chemical balance of formaldehyde and trioxan in the reaction mixture by operating at high evaporation speed.
However, this operation mode results in a low trioxan 5'î 7~
The trioxan formed at elevated temperatures in the presence of acidic catalysts is separated from the reaction mixture by distillation. Generally, the synthesis vapor containing trioxan, water and formaldehyde as well as by-products of the synthesis is rectified either according to U.S.
Patent No. 2 304 080 in a rectifying column mounted onto the reactor, or according to British Patent No. 1 012 372 in a column provided with rectifier and discharge section.
The fraction rich in trioxan so obtained is further worked up by extraction and/or another known separation process.
It is known that the time yields (g of trioxan per kg of formaldehyde and hour) of trioxan synthesis are low.
According to German Patent No. 1 135 491, for example, a time yield of 152 g of trioxan per kg of formaldehyde and hour is attained by simple distillation of the reaction mixture from the reaction vessel. The low time yields cause necessarily long residence times in the manufacture of trioxan from aqueous formaldehyde solutions. Moreover, large reaction volumes are required in order to attain industrially satisfactory space/time yields (g of trioxan per liter of reaction volume and time).
In order to increase the space/time yields of trioxan synthesis, it has been proposed to disturb substantially the chemical balance of formaldehyde and trioxan in the reaction mixture by operating at high evaporation speed.
However, this operation mode results in a low trioxan 5'î 7~
- 3 - HOE 78/F 266 concentration in the synthesis vapor (see E. Bartholomé, Chem. Ing. Techn. 43, (1971) 597), the work-up of which vapors requires great energy expenditure.
In German Auslegeschrift No. 1 543 390, there is furthermore described a process for which a maximum time yield of 1090 g of trioxan per kg of formaldehyde and hour is indicated. In this process, an aqueous formaldehyde solution is heated to boiling in a circulation evaporator in the presence of acidic catalysts, and the synthesis vapors rich in trioxan are then removed via a column mounted on top of the reactor. To this column, reaction solution being in a chemical balance is fed to meet the synthesis vapor, in order to ensure that, even at high evaporation speed, the trioxan concentration of the syn-thesis vapors attains the equilibrium value which generallyis maintained only at low evaporation speed and which corresponds to the distribution equilibrium of trioxan in gaseous and liquid phase.
The disadvantage of the process in accordance with this German Auslegeschrift No. 1 543 390 resides in the fact that additional equipment is required, which involves considerable increase of the reactor volume and thus a decrease of the space/time yields. In the process as described, the equipment which is contacted with the reaction liquid consists therefore of the reactor as such, an evaporator, a pump, a long tubular duct, optionally with dwelling vessel, and a column. All these devices must be made from materials which resist to an acidic ~for example sulfuric acid-containing) formaldehyde solu-'7'~
In German Auslegeschrift No. 1 543 390, there is furthermore described a process for which a maximum time yield of 1090 g of trioxan per kg of formaldehyde and hour is indicated. In this process, an aqueous formaldehyde solution is heated to boiling in a circulation evaporator in the presence of acidic catalysts, and the synthesis vapors rich in trioxan are then removed via a column mounted on top of the reactor. To this column, reaction solution being in a chemical balance is fed to meet the synthesis vapor, in order to ensure that, even at high evaporation speed, the trioxan concentration of the syn-thesis vapors attains the equilibrium value which generallyis maintained only at low evaporation speed and which corresponds to the distribution equilibrium of trioxan in gaseous and liquid phase.
The disadvantage of the process in accordance with this German Auslegeschrift No. 1 543 390 resides in the fact that additional equipment is required, which involves considerable increase of the reactor volume and thus a decrease of the space/time yields. In the process as described, the equipment which is contacted with the reaction liquid consists therefore of the reactor as such, an evaporator, a pump, a long tubular duct, optionally with dwelling vessel, and a column. All these devices must be made from materials which resist to an acidic ~for example sulfuric acid-containing) formaldehyde solu-'7'~
- 4 - HOE 78/F 266 tion having a temperature of about 100C. The general disadvantages of corrosion-proof reactors are described in German Auslegeschrift No. 2 103 687. When calculating the space/time yields, considerably lower values are obtained than those indicated in German Auslegeschrift No. 1 543 390.
In German Offenlegungsschrift No. 2 428 719, there is furthermore described a process for the separation of trioxan from aqueous solutions containing trioxan and formaldehyde, according to which from 5 to 15 weight ~ of the solutions are di-stilled off at temperatures of below 100C under reduced pressure and at a residence time of less than 1 minute, and subsequently the trioxan is isolated from the distillate. This operation mode has the disadvantage of poor time yields.
It is therefore the object of this invention to provide a process for the manufacture of trioxan, op-tionally together with cyclic formals, in which the dis-advantages of the state of the art are avoided or at least considerably reduced.
In accordance with the invention, this object is achieved by an operation mode according to which defined amounts of the circulating reaction mixture are eva-porated in a circulation reactor with evaporator.
The present invention provides therefore a process for the continuous manufacture of trioxan from aqueous formaldehyde solutions, in the presence of acidic cata-lysts, in a circulation reactor with evaporatGr, at a residence time in the range of from 2 to 240 minutes, A. S 7 7 L~
In German Offenlegungsschrift No. 2 428 719, there is furthermore described a process for the separation of trioxan from aqueous solutions containing trioxan and formaldehyde, according to which from 5 to 15 weight ~ of the solutions are di-stilled off at temperatures of below 100C under reduced pressure and at a residence time of less than 1 minute, and subsequently the trioxan is isolated from the distillate. This operation mode has the disadvantage of poor time yields.
It is therefore the object of this invention to provide a process for the manufacture of trioxan, op-tionally together with cyclic formals, in which the dis-advantages of the state of the art are avoided or at least considerably reduced.
In accordance with the invention, this object is achieved by an operation mode according to which defined amounts of the circulating reaction mixture are eva-porated in a circulation reactor with evaporator.
The present invention provides therefore a process for the continuous manufacture of trioxan from aqueous formaldehyde solutions, in the presence of acidic cata-lysts, in a circulation reactor with evaporatGr, at a residence time in the range of from 2 to 240 minutes, A. S 7 7 L~
- 5 - HOE 78/F 266 wherein the amount of vapor leaving thè system is from 0.1 to 4 ~ relative to the amount of product circulating through the evaporator.
Subject of the present invention is furthermore a continuous process for the simultaneous manufacture of trioxan and cyclic formals, which comprises treating an aqueous for~Hldehyde solution containing one diol and/or at least one epoxide in the manner as described above.
According to the process of the invention, there are surprisingly obtained in the synthesis vapor trioxan concentrations corresponding to the attainable maximum equilibrium value, even at high evaporation speed.
The trimerization reaction of formaldehyde in order to obtain trioxan is carried out in known manner by reac-ting aqueous, generally 30-80 %, pref~rably 40-70 %, formal~e~7de solu-tions, optionally with addition of known anti-foaming agents, in the presence of known acidic catalysts such as mineral acids, strong organic bases or other acidic catalysts in an amount as required for maintaining a corresponding catalytic activity. Suitable acidic cata-lysts, which have to be less volatile than the reaction mixture, are for example sulfuric acid, phosphoric acid, p-toluenesulfonic acid or acidic ion exchangers. The ~ quantity is not critical and generally in a range of from 2 to 25 %, preferably 2 to 10 %.
~ hen according to the above process variant of the invention a mixture of trioxan and at least a cyclic formal is to be manufactured, from 1 to 25 weight %, preferably 2 to 15 weight %, relative to formaldehyde, of at least _ _ 5'7'7'~
Subject of the present invention is furthermore a continuous process for the simultaneous manufacture of trioxan and cyclic formals, which comprises treating an aqueous for~Hldehyde solution containing one diol and/or at least one epoxide in the manner as described above.
According to the process of the invention, there are surprisingly obtained in the synthesis vapor trioxan concentrations corresponding to the attainable maximum equilibrium value, even at high evaporation speed.
The trimerization reaction of formaldehyde in order to obtain trioxan is carried out in known manner by reac-ting aqueous, generally 30-80 %, pref~rably 40-70 %, formal~e~7de solu-tions, optionally with addition of known anti-foaming agents, in the presence of known acidic catalysts such as mineral acids, strong organic bases or other acidic catalysts in an amount as required for maintaining a corresponding catalytic activity. Suitable acidic cata-lysts, which have to be less volatile than the reaction mixture, are for example sulfuric acid, phosphoric acid, p-toluenesulfonic acid or acidic ion exchangers. The ~ quantity is not critical and generally in a range of from 2 to 25 %, preferably 2 to 10 %.
~ hen according to the above process variant of the invention a mixture of trioxan and at least a cyclic formal is to be manufactured, from 1 to 25 weight %, preferably 2 to 15 weight %, relative to formaldehyde, of at least _ _ 5'7'7'~
- 6 - HOE 78/F 266 one diol and/or at least one epoxide must be added to the aqueous formaldehyde solution.
Suitable diols for this application are above all 1,2~ 3- and ~ , ~diols. Alternatively, the correspon-5 ding epoxides may be used instead of the 1,2-diols, or mixtures of both compounds. Prefexably, diols are employed the cyclic formals of which have boiling points below 150C and/or, with water, form low-boiling azeotropic mixtures, or are volatile in steam. Suitable are for example ethyleneglycol, ethylene oxide, propyleneglycol-1,2, propylene oxide, propyleneglycol-1,3, butanediol-1,2, butanediol-1,3, butanediol-1,4, and butene(3)-diol-1,2.
Preferably, ethyleneglycol or ethylene oxide, propylene-glycol-1,2 and butanediol-1,4 are used in accordance with the invention, and especially ethyleneglycol or ethylene oxide.
In accordance with the invention, the reaction is carried out in a state-of-the-art circulation reactor with evaporator. Suitable are for example forced circulation evaporators, falling-film evaporators or thin-film evapo-rators with forced circulation. Such systems are described for example in Ullmann, vol. 1 (1951), 3rd. ed., pp 533-53?. Especially advantageous are forced circulation eva-~ porators. - -The residence time of the reaction mixture in the reactor system is from 2 to 240 minutes, preferably 5 to 120 minutes, and especially 15 to 60 minutes. The tempera-tures of the reaction mixture are from 50 to 150C-, prefer-ably 95 to 110C, depending on the pressure.
'7'7'~
Suitable diols for this application are above all 1,2~ 3- and ~ , ~diols. Alternatively, the correspon-5 ding epoxides may be used instead of the 1,2-diols, or mixtures of both compounds. Prefexably, diols are employed the cyclic formals of which have boiling points below 150C and/or, with water, form low-boiling azeotropic mixtures, or are volatile in steam. Suitable are for example ethyleneglycol, ethylene oxide, propyleneglycol-1,2, propylene oxide, propyleneglycol-1,3, butanediol-1,2, butanediol-1,3, butanediol-1,4, and butene(3)-diol-1,2.
Preferably, ethyleneglycol or ethylene oxide, propylene-glycol-1,2 and butanediol-1,4 are used in accordance with the invention, and especially ethyleneglycol or ethylene oxide.
In accordance with the invention, the reaction is carried out in a state-of-the-art circulation reactor with evaporator. Suitable are for example forced circulation evaporators, falling-film evaporators or thin-film evapo-rators with forced circulation. Such systems are described for example in Ullmann, vol. 1 (1951), 3rd. ed., pp 533-53?. Especially advantageous are forced circulation eva-~ porators. - -The residence time of the reaction mixture in the reactor system is from 2 to 240 minutes, preferably 5 to 120 minutes, and especially 15 to 60 minutes. The tempera-tures of the reaction mixture are from 50 to 150C-, prefer-ably 95 to 110C, depending on the pressure.
'7'7'~
- 7 - HOE 78/F 266 The reaction product consisting of trioxan, form-aldehyde and water and optionally cyclic formals is removed from the reactor system by distillation with the aid of the evaporator. Operations may be carried out under normal pressure, under reduced pressure, for example of from 15 to 950 mbars, or under elevated pressure of, for example 1 to 4 bars. Preferred is normal pressure.
In accordance with the process of the invention, the amount of distillate leaving the system, relative to the amount of product circulating through the evaporator, is in the range of from 0.1 to 4.0 %, preferably from 0,2 to 3.0 %, and especially from 0.5 to 2.0 ~. Evaporation of the required amount can be ensured by means of the pump of a forced circulation evaporator, the conveying capacity of which pump must be adjusted in such a manner that it corresponds to the 1000- to 20-fold, preferably 500- to 33-fold, and especially 200- to 50-fold, of the product amount leaving the system per hour. According to a further embodiment of the invention, a partial current of the circulating mixture can be derived before entering the evaporator and united before entry into the vapor zone of the reaction vessel with the product current leaving the evaporator, thus reducing the speed of flow in the ~ evaporator. This partial current must be adjusted in its quantity in such a manner that the product leaving the system amounts to 0.1 to 4 % of the total pump-circulated product. For example, the partial current may amount to twice the product quantity circulating through the eva-porator.
7~ ~
In accordance with the process of the invention, the amount of distillate leaving the system, relative to the amount of product circulating through the evaporator, is in the range of from 0.1 to 4.0 %, preferably from 0,2 to 3.0 %, and especially from 0.5 to 2.0 ~. Evaporation of the required amount can be ensured by means of the pump of a forced circulation evaporator, the conveying capacity of which pump must be adjusted in such a manner that it corresponds to the 1000- to 20-fold, preferably 500- to 33-fold, and especially 200- to 50-fold, of the product amount leaving the system per hour. According to a further embodiment of the invention, a partial current of the circulating mixture can be derived before entering the evaporator and united before entry into the vapor zone of the reaction vessel with the product current leaving the evaporator, thus reducing the speed of flow in the ~ evaporator. This partial current must be adjusted in its quantity in such a manner that the product leaving the system amounts to 0.1 to 4 % of the total pump-circulated product. For example, the partial current may amount to twice the product quantity circulating through the eva-porator.
7~ ~
- 8 - HOE 78/F 266 ~ he synthesis vapor leaving the reactor system is concentrated in usual manner in vapor or condensate form by means of a rectification as described for example in British Patent No. 1 012 372. The fraction rich in trio-xan obtained which contains possibly cyclic formals can bepurified, for example by extraction with a water-immiscible solvent for trioxan and possibly cyclic formals such as methylene chloride, and subsequent neutralization and fractional distillation or crystallization. Other known separation processes may alternatively be applied, such as described for example-in Process Economics Program, Stanford Institute Report 23 (1967), p. 181, or German Offenlegungsschrift No. 1 570 335.
The process of the invention is especially advantage-ous also with respect to operational technique, because apart from, for example, a pump mounted between reactor and evaporator, an increase of the reaction zone by ad-ditional equipment is not required in order to produce a synthesis vapor having the maximum trioxan content which corresponds to the equilibrium value in the gaseous phase for the distribution balance of trioxan in liquid and gaseous phase, even at high evaporation speed.
According to processes hitherto described, this trioxan content can be obtained only when operating at low eva-poration speed, or according to the complicated andexpensive operation mode of German Auslegeschrift No.
1 543 390. In accordance with the invention, space/time yields can be attained which are considerably superior to those resulting ln accordance with the state of the art.
5'7'~4
The process of the invention is especially advantage-ous also with respect to operational technique, because apart from, for example, a pump mounted between reactor and evaporator, an increase of the reaction zone by ad-ditional equipment is not required in order to produce a synthesis vapor having the maximum trioxan content which corresponds to the equilibrium value in the gaseous phase for the distribution balance of trioxan in liquid and gaseous phase, even at high evaporation speed.
According to processes hitherto described, this trioxan content can be obtained only when operating at low eva-poration speed, or according to the complicated andexpensive operation mode of German Auslegeschrift No.
1 543 390. In accordance with the invention, space/time yields can be attained which are considerably superior to those resulting ln accordance with the state of the art.
5'7'~4
- 9 - HOE 78/F 266 Furt-hermore, the process of the invention allows the synthesis of trioxan at a minimum energy consumption;
it is thus distinguished by a favorable energy balance.
The operation mode of the invention is furthermore distinguished by the fact that the short residence times at high evaporation speed reduce the formation of by-products such as formic acid. Low catalyst acid concen-trations or the use of ion exchangers have an identical effect.
The following examples illustrate the invention.
E X A M P L E S
The test apparatus is shown in the accompanying drawing. The reactor consists of the vessel (1), the eva-porator (2), in special cases a tubular heat exchanger, and the pump (3). Via duct (4), aqueous formaldehyde solution is after-dosed continuously. The acidic catalyst is introduced into the reaction vessel 11) together with aqueous formaldehyde solution, while the distillate is removed via duct (5).
700 g each of a mixture (400 g in the Comparative Tests 4 and 5) of 90 parts of a 63.5 ~ aqueous formaldehyde solution and 10 parts of concentrated sulfuric acid are introduced into the reaction vessel (1), which is pre-heated to 95C. The mixture is pumped through the evapora-tor (2) by means of the pump (3). Depending on the intended throughput, the evaporator is heated at varying temperatures.
The evaporated portion of the pump-circulated reaction mixture is totally condensed in a ~uenching system, and the condensate is examined for its content of trioxan and :~P~'7'7'~
it is thus distinguished by a favorable energy balance.
The operation mode of the invention is furthermore distinguished by the fact that the short residence times at high evaporation speed reduce the formation of by-products such as formic acid. Low catalyst acid concen-trations or the use of ion exchangers have an identical effect.
The following examples illustrate the invention.
E X A M P L E S
The test apparatus is shown in the accompanying drawing. The reactor consists of the vessel (1), the eva-porator (2), in special cases a tubular heat exchanger, and the pump (3). Via duct (4), aqueous formaldehyde solution is after-dosed continuously. The acidic catalyst is introduced into the reaction vessel 11) together with aqueous formaldehyde solution, while the distillate is removed via duct (5).
700 g each of a mixture (400 g in the Comparative Tests 4 and 5) of 90 parts of a 63.5 ~ aqueous formaldehyde solution and 10 parts of concentrated sulfuric acid are introduced into the reaction vessel (1), which is pre-heated to 95C. The mixture is pumped through the evapora-tor (2) by means of the pump (3). Depending on the intended throughput, the evaporator is heated at varying temperatures.
The evaporated portion of the pump-circulated reaction mixture is totally condensed in a ~uenching system, and the condensate is examined for its content of trioxan and :~P~'7'7'~
- 10 - HOE 78/E 266 formaldehyde. 63.5 ~ Formaldehyde solution is after-dosed in amounts corresponding to the evaporated portion.
The test time was 5 hours in each case.
The results and those of the Comparative Tests are listed in Tables 1 and 2.
Examples 1 to 3 (Table 1) demonstrate that the trioxan concentrations in the synthesis vapor are inde-pendent from the throughput when the evaporated portion, that is, the vapor leaving the system, relative to the product amount circulating through the evaporator, is smaller than 4 %, while in the case of high evaporation rates (10 %), the trioxan content in the reaction vapor decreases considerably when the throughput rises (~ompara-tive Tests 4 and 5).
A comparison of Example No. 3 with Comparative Test 6 (according to Example 2 of German Auslegeschrift No.
1 543 390) demonstrates that, although residence time , and trioxan concentration in the synthesis vapor are identical, considerably higher space/time yields result in the process of the invention due to the substantially lower reaction volume.
'7'7~
The test time was 5 hours in each case.
The results and those of the Comparative Tests are listed in Tables 1 and 2.
Examples 1 to 3 (Table 1) demonstrate that the trioxan concentrations in the synthesis vapor are inde-pendent from the throughput when the evaporated portion, that is, the vapor leaving the system, relative to the product amount circulating through the evaporator, is smaller than 4 %, while in the case of high evaporation rates (10 %), the trioxan content in the reaction vapor decreases considerably when the throughput rises (~ompara-tive Tests 4 and 5).
A comparison of Example No. 3 with Comparative Test 6 (according to Example 2 of German Auslegeschrift No.
1 543 390) demonstrates that, although residence time , and trioxan concentration in the synthesis vapor are identical, considerably higher space/time yields result in the process of the invention due to the substantially lower reaction volume.
'7'7~
- 11 - HOE 78/F 266 Table l Example Throughput Trioxan Evaporated Conversion Residence No. kg/kg-hLn the amount rate ti~.e . _ _~
1 1.07 20.6 0.93 32.4 0.94 2 1.67 20.5 1.5 32.3 0.6 3 2.91 2~ 4 1.3 32.1 0.3 4 * 0.4220.3 10.0 32.0 1.4 . . 0.97 8.7 10.0 13.7 0.7 *
Comparative Tests
1 1.07 20.6 0.93 32.4 0.94 2 1.67 20.5 1.5 32.3 0.6 3 2.91 2~ 4 1.3 32.1 0.3 4 * 0.4220.3 10.0 32.0 1.4 . . 0.97 8.7 10.0 13.7 0.7 *
Comparative Tests
- 12 - HOE 78/F 266 .~
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Claims (8)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the continuous preparation of trioxan from an aqueous solution of formaldehyde in the presence of an acid catalyst in a circulation reactor with evaporator at a residence time in the range of from 2 to 240 minutes, wherein the amount of vapor leaving the system is from 0.1 to 4% relative to the amount of product circulating through the reactor.
2. A process as claimed in claim 1 in which a cyclic formal is also formed and the aqueous solution contains, in addition to formaldehyde, at least one member of the group of diols and epoxides.
3. A process as claimed in claim 2 in which the member of the group of diols and epoxides is selected from the group of ethylene glycol, ethylene oxide, propyleneglycol-1,2, and butanediol-1,4.
4. A process as claimed in claim 1, claim 2 or claim 3 which comprises using a forced circulation evaporator.
5. A process as claimed in claim 1, claim 2 or claim 3 wherein the vapor amount leaving the system is in the range of from 0.2 to 3%.
6. A process as claimed in claim 1, claim 2 or claim 3 which comprises deriving a partial current of the circulating mixture before entry into the evaporator and uniting it before entry into the vapor zone of the reactor with the product current leaving the evaporator.
7. A process as claimed in claim 1, claim 2 or claim 3 wherein the residence time is 15 to 60 minutes.
8. A process as claimed in claim 1, claim 2 or claim 3 wherein the process is carried out at a temperature of from 50 to 150°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19782853091 DE2853091A1 (en) | 1978-12-08 | 1978-12-08 | METHOD FOR THE CONTINUOUS PRODUCTION OF TRIOXANE |
| DEP2853091.8 | 1978-12-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1125774A true CA1125774A (en) | 1982-06-15 |
Family
ID=6056660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA341,491A Expired CA1125774A (en) | 1978-12-08 | 1979-12-07 | Process for the continuous manufacture of trioxan |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0012304B1 (en) |
| JP (1) | JPS5581876A (en) |
| AT (1) | ATE644T1 (en) |
| CA (1) | CA1125774A (en) |
| DE (2) | DE2853091A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2943984A1 (en) * | 1979-10-31 | 1981-05-14 | Hoechst Ag, 6000 Frankfurt | METHOD AND DEVICE FOR THE CONTINUOUS PRODUCTION OF TRIOXANE |
| DE3445921A1 (en) * | 1984-12-17 | 1986-06-19 | Hoechst Ag, 6230 Frankfurt | METHOD FOR THE CONTINUOUS PRODUCTION OF TRIOXANE |
| DE59510758D1 (en) * | 1994-09-29 | 2003-09-11 | Ticona Gmbh | Natural circulation reactor and use |
| DE4434845A1 (en) | 1994-09-29 | 1996-04-04 | Hoechst Ag | Natural circulation reactor and use |
| DE102005051974A1 (en) * | 2005-10-31 | 2007-05-03 | Basf Ag | Preparing trioxane and comonomer, useful for preparing trioxane based (co)polymer, comprises converting formaldehyde and co-monomer educt to trioxane and co-monomer, and distillating the obtained reaction mixtures |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE656705A (en) * | 1963-12-05 | |||
| FR1429161A (en) * | 1964-05-02 | 1966-02-18 | Joseph Meissner Kommanditgesel | Process for the preparation of a trioxane solution |
| IT998150B (en) * | 1973-06-15 | 1976-01-20 | Sir Soc Italiana Resine Spa | PROCEDURE FOR THE PRODUCTION OF TRIOXANE |
-
1978
- 1978-12-08 DE DE19782853091 patent/DE2853091A1/en not_active Withdrawn
-
1979
- 1979-12-01 DE DE7979104818T patent/DE2962070D1/en not_active Expired
- 1979-12-01 AT AT79104818T patent/ATE644T1/en not_active IP Right Cessation
- 1979-12-01 EP EP79104818A patent/EP0012304B1/en not_active Expired
- 1979-12-07 CA CA341,491A patent/CA1125774A/en not_active Expired
- 1979-12-07 JP JP15825879A patent/JPS5581876A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE2962070D1 (en) | 1982-03-11 |
| ATE644T1 (en) | 1982-02-15 |
| EP0012304A1 (en) | 1980-06-25 |
| EP0012304B1 (en) | 1982-02-03 |
| JPH0147474B2 (en) | 1989-10-13 |
| DE2853091A1 (en) | 1980-06-26 |
| JPS5581876A (en) | 1980-06-20 |
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