KR820001199B1 - Process for production of tert-butanol from mixed butlyenes - Google Patents

Abstract

Isobutene was hydrated to Me3COH over Mo, W, and V heteropoly acids at < 100 ≰C. Thus, a mixt. of isobutene, 1-butene, 12-molybdophosphoric acid, and water was stirred 1 hour at 60≰C and 8.5 atm to give Me3COH (100 % selectivity) with 89% conversion of isobutene.

Description

Process for preparing tert-butanol from butylene mixture

1 is an exemplary view illustrating the result of selective hydration of isobutylene using an aqueous solution of molybdenum phosphate 12 as a typical catalyst in Example 2 of the present invention.

2 is an illustration of a continuous reaction system according to the method of the present invention.

3 is a perspective view of another continuous reaction system according to the method of the present invention.

The present invention relates to a process for preparing tert-butanol by selective hydration of isobutylene in a hydrocarbon mixture consisting of isobutylene and tert-butene.

tert-butanol is used as an industrial starting material for the preparation of various substances. For example, tert-butanol is used as a starting material for the production of methacrylonitrile or methacrylate, a medium for producing methyl methacrylate, and methacrylonitrile or methacrone is used for the hydration of n-butene. It cannot be obtained from the starting sec-butanol.

Conventionally, in selectively hydrating isobutylene in a mixture of isobutylene and n-butene, 50-65% sulfuric acid or hydrochloric acid, hydrochloric acid of metal chlorine, strong acidic ion exchange resin, or solid acid is used as a catalyst. However, the method using sulfuric acid produces dimers, trimers and polymers of isobutylene, and some of n-butenes. In particular, 1-butene tends to hydrate with sec-butanol. Moreover, the strong corrosion of sulfuric acid requires expensive corrosion resistant materials and requires inexpensive manufacturing equipment. The use of inorganic acids, such as hydrochloric acid, or halides, such as tin chloride, has the drawback of tert-butyl halides and also presents problems for the material due to significant corrosion.

In order to avoid these drawbacks, methods of using strong acidic ion exchange resins or insoluble solid acids have been provided, but their hydration activity is low and generally a high hydration temperature in the range of 120-200 ° C is desired. Moreover, at this temperature the service life of the ion exchange resin is short, the filtration of finely ground and ground particles from the fluid which is very difficult, and as a result the process becomes complicated. Due to the essentially elevated temperature the conversion of isobutylene to tert-butanol is further reduced in terms of chemical equilibrium.

Therefore, the concentration of tert-butanol in solution at equilibrium is lowered when a catalyst is required which requires high temperatures. As a result, there is a drawback that the reaction apparatus becomes large from an industrial point of view.

In general, it is known that heteropolyacid solutions such as tungsten silicate, molybdenum phosphate and tungsten phosphate can be used to hydrate olefins. However, as long as an olefin mixture of n-butylene and isobutylene is present, it is possible to use conventional industrial materials such as stainless steel, for example, as structural materials, and unreacted n while maintaining the initial catalytic activity for a long time. A catalyst with high activity up to the appropriate reaction conditions capable of converting isobutylene to tert-butanol without the formation of polymers such as dimers and trimers of isobutylene with butene is yet unknown.

Furthermore, British Patent Nos. 1,281,120, JP-A-1975-35,052 and 1975-35,053 describe the hydrolysis of 1: 1 mixtures of isobutylene and n-butene in the presence of heteropolyacid ions. In consideration of the corrosion defects and side reactions of the reactor material, hydration was carried out at high temperature and high pressure (200 ° C., 250 kg / cm 2) while maintaining the low concentration of heteropoly acid and the high pH of the reaction, and the product of sec-butanol and tert-butanol as a product: A mixture of 1 is produced.

In this case, much time is required to complete the reaction due to the low activity of the catalyst.

In addition, selective hydration of isobutylene to tert-butanol in the presence of n-butene cannot be achieved.

In addition, Japanese Patent Application Laid-Open No. 1976-13,711 discloses that hydration of isobutylene is carried out at a concentration of 10-70% by weight of heteropolyacid at a temperature of 100-170 ° C, and corrosion of reactor materials and by-products of olefin polymers are prevented, and the life of the catalyst is prevented. It has been reported that hyperhydration activity is satisfactory.

However, no publication has been made on the selective hydration of isobutylene in mixed butylenes. Also in reaction systems using conventional catalysts, the resulting tert-butanol is essentially in solution phase. Thus, the remaining hydrocarbon mixture is removed, for example, by "separation of the organic liquid phase from the aqueous phase" and then tert-butanol is recovered in the liquid phase by conventional methods such as distillation and salt precipitation under reduced pressure.

However, in recovering tert-butanol from the liquid phase by distillation, a polymer is produced and a large amount of heat is required. The distillate contains more water than the azeotrope of water and tert-butanol, and in general the concentration of tert-butanol is not possible to increase above 80-89%.

Japanese Patent Application No. 1972-4165 discloses a method of hydrating isobutylene in the presence of an acid catalyst and an inorganic acid salt to prepare tert-butanol.

However, this method uses sulfuric acid as a catalyst and hydrocarbons such as n-butene are not liquefied.

The resulting tert-butanol contains large amounts of water, as is clearly understood in the examples of the prior art, and also high concentration products cannot be obtained.

In addition, the presence of sulfuric acid causes strong corrosion of the reactor material, and since a large amount of diisobutylene is by-produced, this method has little industrial value.

Therefore, when the present invention is specifically described, a hydrocarbon mixture comprising isobutylene and n-butene is at least one condensation coordination atom selected from the group consisting of Mo, W and V at a temperature of 100 ° C. or less. It provides a method for the preparation of tert-butanol comprising contacting with a solution containing polyacid to cause selective hydration of isobutylene.

Another method of the present invention comprises tert as described above comprising separating the remaining hydrocarbons as a result of the liquid mixture hydration reaction at a temperature of at least 70 ° C. and also recovering or purifying tert-butanol at a temperature of at least 70 ° C. It provides a method for producing butanol.

More specifically, the present invention provides a method for producing tert-butanol as described above, wherein the selective hydration of isobutylene is carried out in a 5-30% by weight tert-butanol liquid phase based on the total amount of the liquid phase. will be.

Suitable hydrocarbon mixtures containing isobutylene and n-butene for use in the present invention are isobutylene and saturated hydrocarbons such as Cis-2-butene, trans-2-butene, propane, butane, pentane or aromatic hydrocarbons and n -B mixtures of butenes and C by-products in fluid catalytic crackers of petroleum₃ C at the time of naphtha cracking as a distillate, a distillate of catalytic dehydrogenation of n-butene and the so-called main component₄Lung B-B fractions containing isobutylene and n-butene obtained by removing most of butadiene from the fractions.

The heteropolyacid that can be used as a catalyst in the present invention has at least one condensation ligand selected from the group consisting of Mo, W and V, and may additionally have other condensation coordination atoms such as Nb and Ta.

In addition, the heteropolyacids used are selected from the group consisting of P, Si, As, Ge, Ti, Ce, Tb, Mn, Ni, Te, I, Co, Cr, Fe, Ga, B, V, Pt, Be and Zn. It has one central atom.

In the present invention, the atomic ratio of the condensation coordination atom to the central atom in the heteropolyacid is typically used in the range of about 2.5-12. In addition to the heteropolyacids of the monomers, polymers of heteropolyacids such as dimers or trimers of heteropolyacids can be used in the present invention.

Heteropolyacids usable in the present invention include, for example, 12-molybdenum phosphate, 2-phosphate-5-molybdenum, 12-tungsten phosphate, 12-molybdenum phosphate tungsten, 6-molybdo-6-tungsten phosphate, 12 Molyblyphdobanadophosphate, 11-molybdo-1-phosphate banana, 12-molybdo tungstovabanadophosphoric acid, 12-tungstobanadophosphoric acid, 12-molybdobophosphoric acid , 12- tungsten silicate, 12- molybdenum silicate, 12-molybdo tungstostosilic acid, 12-molybdo tungstobanadosilic acid, 12- tungstoboric acid, 12-molybdenum borate, 12-mol boric acid Libdo tungsten, 12-molybdobanadoboric acid, 12-molybdo tungstobanadoboric acid, 9-molybdonic kelic acid, 6-molybdocobaltic acid, 6-tungstocobaltic acid, 11 Molybdoacetic acid, 12-tungstoacetic acid, 2-tungstogeric acid and 18-tungsto-2-acenic acid.

Heteropolyacids used in the process of the invention are used in the form of aqueous solutions.

The concentration of heteropoly acid used is not particularly limited. Rather, the high concentration of heteropolyacid in aqueous solution hydration of isobutylene makes the reaction proceed faster, but it is unnecessary to use soluble heteropolyacid in water. On the other hand, excessively low concentrations of heteropolyacids reduce the reaction rate.

Suitable concentrations of heteropolyacids in the hydration reaction that may typically be used in the present invention range from about 10% by weight, based on the total amount of water and heteropolyacids, to saturated aqueous solutions of heteropolyacids at reaction temperatures. According to the process of the present invention, the heteropolyacid has been prepared in advance, and the compound having a central atom or a compound having a condensation coordination atom, which is added to the hydration reaction, is first added separately to the reactor in the form of a heteropolyacid, and the resulting heteropolyacid is Contact with the hydrocarbon mixture comprising isobutylene and n-butene.

The hydration of the process of the present invention is desired to proceed at a temperature lower than 100 ℃. Preferred temperature ranges are in the range of 30-80 ° C.

When the hydration temperature is higher than 100 ℃, the hydration of n-butene occurs quickly, the purity of the product tert-butanol decreases, moreover, oligomers such as dimers or trimers of isobutylene. The production of sec-butyl, tert-butyl ether begins to increase, leading to an increase in the production of, and a tendency to interfere with the purification of tert-butanol and also to produce dangerous peroxides.

On the other hand, especially when the hydration reaction temperature is lower than 80 ℃ hydration of n-butene hardly occurs, it is possible to obtain tert-butanol of high purity.

If the hydration reaction according to the method of the present invention is carried out at 30 캜 or lower, the reaction rate is disadvantageously reduced. Specifically 12-molybdophosphoric acid, 12-molybdoxilic acid, 12- tungstosilic acid and 12- tungstophosphoric acid are better heteropolyacids that can be used in the present invention.

The process of the present invention is carried out at the reaction force or under the high pressure necessary to maintain water, isobutylene and n-butene in the liquid phase. An inert gas such as nitrogen may be used in the pressure regulation.

In addition, acidic substances and strongly acidic ion exchange resins containing sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, inorganic acids such as silicic acid, aromatic sulfuric acid such as P-polene sulfoxane, and acidic to acidic heteropolyacids having less than 0.01 in the hydration reaction of the present invention. When present in the weight ratio of material, the good selectivity of isobutylene and the catalytic activity of heteropoly acid to tert-butanol can be maintained and the stability of heteropoly acid can also be improved. As a result, the service life of the heteropolyacid can be extended. However, when the amount of acid used is too high, side effects are caused by each acid selected. The use of sulfuric acid, for example, increases the formation of byproducts such as oligomers of isobutylene and sec-butanol, leading to poor corrosion of the reactor.

In the present invention, the hydrocarbon remaining after the selective hydration of isobutylene needs to be removed from the liquid mixed hydration at a temperature of almost 70 ° C. to avoid dehydration and other side reactions of tert-butanol. In removing the remaining hydrocarbons, for example, the hydrated liquid reaction mixture after the hydration reaction is separated into two liquid phases under pressure, that is, an organic liquid phase containing residual hydrocarbons, and an aqueous solution containing a heteropoly acid as a catalyst, or the organic liquid phase after phase separation Evaporate. If necessary or desired, residual hydrocarbons dissolved in aqueous solution are removed under reduced pressure. The tert-butanol thus prepared is generally obtained in the form of an aqueous solution.

When a high concentration of tert-butanol aqueous solution is desired, the aqueous solution is purified. Recovery and purification of tert-butanol from the aqueous phase separating the remaining hydrocarbons needs to be carried out at a temperature at about 70 ° C. to avoid the formation of by-products of tert-butanol.

In order to recover or purify tert-butanol, methods such as flashing distillation, extraction and salt precipitation are used.

Among these methods, it is preferable to use vacuum distillation in the form of a general distillation, packed column, or play column distillation. It is not good to leave the product of tert-butanol for a long time in a heated state, so it is better to perform the recovery or purification as short as possible.

In the present invention, the aqueous solution of tert-butanol is recycled to the hydration reactor. In this case, the loss of tert-butanol is very small even if the complete recovery of tert-butanol is not performed. In aqueous solution recycling, the concentration of water in the hydration mixture is kept constant by adding water to the reactor in an amount corresponding to the loss of tert-butanol aqueous solution from the hydration system.

On the other hand, if the mixture of remaining hydrocarbons containing isobutylene can be separated from the hydration reaction mixture, this mixture is also recycled to the hydration reactor.

Another specific method of the present invention, as described above, is carried out in the selective hydration of isobutylene in the presence of tert-butanol in an aqueous solution of a hydration reaction mixture consisting of two solution phases, namely an organic liquid phase and an aqueous solution phase. Specifically stated, the amount of tert-butanol is controlled by an organic liquid phase process comprising tert-butanol equivalent to or about the same as the amount produced by the hydration of isobutylene, and in addition, the hydrocarbon supplied The aqueous phase contains almost all heteropolyacids and water in the hydration reaction system.

The amount of tert-butanol in the aqueous phase may be used in the range of 5-30% by weight based on the total weight of the aqueous phase. The organic liquid phase after the hydration reaction contains tert-butanol equivalent to or about the same as the amount produced by the hydration reaction, and the remaining hydrocarbons and aqueous solution phase with a small amount of water are heteropolyacids, water, undissolved hydrocarbons and hydration. It contains tert-butanol in an amount corresponding to or almost equivalent to that added before the reaction.

After separating the organic liquid phase from the aqueous solution phase and removing the remaining hydrocarbons from the organic liquid phase thus separated, a high concentration tert-butanol aqueous solution can be obtained. This aqueous phase can be used for selective hydration of isobutylene in the future. Specifically, 12- tungstosilic acid and 12- tungstophosphoric acid are preferable because the amount of tert-butanol required for the progress of the hydration reaction is advantageously small. It is evident that the amount of tert-butanol present in the hydration system will vary depending on the amount of heteropoly acid selected, ie the heteropoly acid used, the reaction temperature and other factors selected. In the selective hydration reaction in such isobutylene aqueous solution or partial removal of tert-butanol may be recycled to the hydration reaction. When the hydration reaction of the present invention using tert-butanol is conducted in the presence of an inorganic acid salt, the amount of tert-butanol during the hydration reaction is reduced.

As described above, it is necessary in accordance with the present invention to convert tert-butanol to the same or almost the same amount as is prepared in the organic liquid phase of the reaction mixture in isobutylene. When no inorganic acid salt is added to the hydration reaction, the tert-butanol distribution coefficient for the organic liquid phase is small. Therefore, it is necessary to increase the concentration of tert-butanol in the aqueous solution of the reaction mixture. As a result, a large amount of tert-butanol is required to be present in the aqueous phase.

However, the presence of the inorganic acid salt in the hydration reaction increases the distribution coefficient of tert-butanol in the organic liquid phase in the hydration reaction mixture, and enables the recovery of the tert-butanol produced in the organic liquid phase, and the relatively aqueous solution phase. Reduce the amount of tert-butanol present in the aqueous phase.

Specific examples of suitable inorganic acid salts include sulfates, nitrates, phosphates. Metal halides are not suitable because of their strong corrosiveness. Cations that can be used in the present invention include cations that do not form insoluble salts with the heteropolyacids of the present invention. Specific cations of these cations include Li, Na, Mg, Be, Al, Ni, Cu, Zn, Co, Ag, Fe, Cr and Mn cations. Cari salts and ammonium in the form of insoluble heteropolyacid salts cannot be used.

When the amount of the inorganic salt is too large, the hydration reaction system becomes three liquid phases or two liquid phases and one solid phase. Therefore, the amount of inorganic salt used in the present invention is not a critical point if the hydration reaction system does not have three liquid phases or two and one failure.

Reactors that can be used in the present invention include a tank reactor equipped with an agitator, a multistage compartment reactor equipped with an agitator, an external circulation reactor, a bubble cap reactor, a reactor, a wet wall reactor, and a tube reactor.

The process of the invention is achieved either batchwise semi-continuous or completely continuous.

The advantages of the present invention can be understood in FIG. 1 which describes the result of selective hydration of isobutylene using an aqueous solution of 12-molybdophosphoric acid as the catalyst selected in Example (2). In particular, a temperature lower than 100 ° C, preferably slightly lower than 80 ° C is better. The effect of selective hydration of isobutylene becomes clear, while at the same time the hydration activity of the catalyst at such low temperatures will reduce the amount of by-products such as dimers and trimers of isobutylene.

To more clearly and better understand the present invention, the flow diagram will be described in more detail as shown in the drawings.

The continuous reaction system according to the process of the present invention is described in detail in FIG. 2, where (I) denotes a reactor and (II) denotes a distillation column. Reactor I is supplied via line 2 with a mixture of water and heteropoly acid recycled from distillation column II, simultaneously with a hydrocarbon mixture consisting of isobutylene and n-butene via line 1, and line 3 Supply additional water through).

In reactor (I) the hydrocarbon mixture is contacted in countercurrent with stirring the mixture of recycle liquid and addition water.

The remaining hydrocarbon mixture is collected in reactor (I) via line (5) while an aqueous solution containing tert-butanol is produced, and catalyst is passed through distillation column (II) through line (4) at the bottom of reactor (I). Move to The resulting tert-butanol is recycled at the bottom of the distillation column (II) via line (2) with the added water added via line (3) corresponding to the amount of the aqueous solution constituting the catalyst reduced during the reaction. The resulting tert-butanol is collected at the top of distillation column (II) via line (6) and exits the reaction system.

The continuous reaction system according to the method of the present invention is described in detail in FIG. 3, where (III) is a reactor, (IV) is a decanter and (V) is an evaporator.

At the bottom of reactor (III) is fed a hydrocarbon mixture constituting isobutylene and n-butene via line (8) and additional water via line (7), line (10) to decanter (IV) It supplies a lower bed consisting of water, a catalyst and tert-butanol. Selective hydration of isobutylene is carried out with stirring in reactor (III), the hydration reaction mixture is fed to decanter (IV), and the upper phase in decanter (IV) is transferred to evaporator (V) via line (11). . The remaining hydrocarbon mixture is collected at evaporator V via line 12 by depressurization of evaporator V by heating at atmospheric pressure or under pressure.

The hydrocarbon thus recovered is liquefied by conventional methods such as cooling with brine or cooling after compression. The remaining portion after removal of hydrocarbons in the evaporator V is purified by general distillation and concentrated to a typical tert-butanol aqueous solution containing about 87-92% by weight of tert-butanol.

The lower phase, which is an aqueous phase in the decanter separator IV, is recycled directly to reactor III via line 10 or, if necessary, after distilling a portion of tert-butanol to recycle reactor II.

The following examples illustrate the invention more clearly. However, the present invention is not limited by these examples.

The analysis of the product in these examples was performed as follows. Using dimethoxyethane as the internal standard, the product is diluted about 5 times with methanol, neutralized with caustic soda and analyzed by gas chromatograph under the following conditions.

Apparatus: Hitachi Model 163 Top Temperature: 140 ℃

Packing Agent: Chromosobu 101 Injection Temperature: 160 ℃

Wako Junya Products Co., Ltd. Carrier: Helium 50cc / min.

Tower Length: 2m

Example 1

As shown in Table 1, 10 g of isobutylene, 10 g of 1-butene, 50 g of heteropoly acid, and 100 g of water were added to a 300 ml stainless steel autoclave, and the reaction mixture was stirred at 60 ° C. and 8.5 atm pressure for 1 hour.

The results are as shown in Table 1.

In each case, no production of sec-butanol was detected, 1-butene was unreacted, and no polymer of isobutylene, such as diisobutylene, was detected.

TABLE 1

Example 2

To a 300 ml stainless steel autoclave, 10 g of isobutylene, 10 g of 1-butene, 50 g of 12-molybdosporic acid having an atomic ratio of 1 to 12 P and 100 g of water were added, and the mixture is shown in Table 2. Stir under the same conditions.

The results are shown in the table and FIG.

TABLE 2

Example 3

20 g of a hydrocarbon mixture having a composition as indicated in Table 3 (so-called "waste BB classification") in a 300 ml stainless steel autoclave, 12-tungtophospho having an atomic ratio 1: 12 of P: W 50 g of lactic acid and 100 g of water are added thereto, and the mixture is stirred at a temperature of 60 ° C. and a pressure of 8.5 atm for 1 hour. As a result, only isobutylene was reacted to produce a water compound, tert-butanol. the results are as follow.

Conversion of isobutylene: 77%

Selectivity of isobutylene over tert-butanol: 100

Generation of sec-butanol: undetected

Formation of Dimers, Trimers, and Polymers: Undetected

TABLE 3

[Comparative Example]

10 g of isobutylene, 10 g of 1-butene, 50 g of sulfuric acid, and 50 g of water were added to a 300 ml pressure-resistant glass autoclave, and the mixture was stirred at 60 ° C. and a pressure of 8.5 atm for 1 hour. As a result, isobutylene is hydrated to produce tert-butanol with 90% conversion and the selectivity of tert-butanol is 92%. At the same time, trimers of diisobutylene and isobutylene were prepared in yields of 2% and 6%, respectively, and 1-butene was hydrated to produce Sec-butanol in 4% yield.

Example 4

Into a 300 ml stainless steel autoclave, 10 g of isobutylene, 10 g of 1-butene, and 50 g of 12-tungstophosphoric acid having an atomic ratio of P to W of 12 were added and the mixture was heated at 60 ° C. under a pressure of 8.5 atm. After stirring for an hour, the mixture is left to cool to 20 ° C. The organic liquid phase is separated from a liquid phase containing tert-butanol and a catalyst and degassed at 40 ° C./300 mmHg to give 2.3 g of isobutylene (recovery rate: 23%) in the remaining hydrocarbon mixture. On the other hand, the liquid is supplied to the bottom of the distillation column filled with Naniwa Pack (a stainless steel spiral wire having a length of 3 mm manufactured by Naniwa Tokushu Kanaami Co., Ltd.), filled up to 10 cm in height, and 40 at 150 mmHg under reduced pressure. Distillation at −60 ° C. yielded 12.4% of an aqueous 80% tert-butanol solution at 75% tert-butanol yield. At this time, there was no production of sec-butanol.

In addition, 2.5 g of water, 10 g of isobutylene, and 10 g of 1-butene were added to the remaining aqueous solution containing the catalyst, and the mixture was stirred at a temperature of 60 ° C. and 8.5 atm for 1 hour, yielding 77% yield and 100% selectivity. tert-butanol was obtained.

Example 5

Into a 300 ml stainless steel autoclave, 20 g of the same hydrocarbon mixture as in Example (3), 50 g of 12-molybdorosporic acid having an atomic ratio of 1 to 12 of P to Mo and 100 g of water were added and the mixture was heated to 60 ° C. After stirring for 2 hours at a pressure of 8.5 atm ° C., 0.4 g of isobutylene is obtained by evaporating the organic liquid phase of the hydrocarbon mixture.

On the other hand, when the liquid phase is distilled in the same manner as in Example 4, 15.9 g of 80% tert-butanol is obtained at a yield of 96% tert-butanol and 100% selectivity to tert-butanol.

At this time, there was no production of sec-butanol.

In addition, 3.5 g of water, 10 g of isobutylene and 10 g of 1-butene were added to the remaining aqueous solution, and the mixture was stirred at 60 ° C. and 8.5 atm for 2 hours, whereby sec-butanol, dimer, trimer, and polymer of isobutylene were added. With no yield tert-butanol is obtained with a yield of 96% and 100% selectivity.

Example 6

The apparatus shown in FIG. 2 was used in this example. The reactor (I) used was equipped with a 120 ml reactor and two separators, one at the top of the reactor, the other at the bottom of the reactor, and the reactor was divided into seven compartments, each compartment being a flat, spatula-like stirrer. Stir with The same fractionation, called waste BB, as in Example (3) is fed via line (1) to the bottom compartment of reactor (I) at a rate of 50 ml / hr and at the same time through distillation column (II) through line (2). The recycle liquid containing 12-tungphosphoric acid and water having an atomic ratio of 1: 12 with a weight ratio of 1: 2 from 1 is fed to the top compartment of reactor (I) at a rate of 442 g / hr. In reactor (I), the fractionation and recycle mixture and wastewater called waste B-B are connected in countercurrent to each other at 70 ° C and 10 atm. The remaining hydrocarbon mixture is collected in the top separator of reactor (I) via line (5) while the aqueous solution produces tert-butanol and 12-tungphosphoric acid is fed to the bottom of reactor (I) via line (4). Transfer from the separator to the distillation column (II). The resulting tert-butanol is then collected by distillation at the top of distillation column (II) via line (6) and the aqueous solution containing 12-tungphosphoric acid is passed through line (2) of distillation column (II). At the bottom, the amount corresponding to the amount reduced in the reaction is recycled via line (3) with the added water to the uppermost room of reactor (I) and then exited from the reaction system. The conversion of isobutylene is 95.4%, the amount of isobutylene polymer such as diisobutylene produced is about 1000 ppm based on the weight of tert-butanol produced and the selectivity of isobutylene to tert-butanol is It is quantitative.

Example 7

The method of Example 6 was carried out in a reactor (I) containing 59.7% by weight of 12-molybdophosphoric acid having an atomic ratio of 12:12 by weight of water and P: Mo by weight and 0.3% by weight of phosphoric acid. Was repeated except that the feed was carried out at a rate of 450 g / hr. The conversion of isobutylene is 96.5%. The hydration reaction continued for more than 1000 hours and the conversion of isobutylene was 96.3%.

Example 8

Into a 300 ml stainless steel autoclave, 11.2 g of isobutylene, 16.8 g of 1-butene, 136 g of 12-tungstosilic acid having an atomic ratio of 1:12 of Si to W, 136 g of water, and 41.0 g of tert-butanol were added. And the mixture was stirred at 60 degreeC and 8.5atm for 2 hours.

The conversion of isobutylene is 83.1%. The reaction mixture is left to stand and then separated into two phases.

Evaporation of the hydrocarbon mixture remaining on the upper layer at atmospheric pressure yields 13.5 g of concentrated tert-butanol containing 90% by weight of tert-butanol and 9.0% by weight of water. The lower layer contains 40.8 g of tert-butanol.

The selectivity of isobutylene over tert-butanol is almost quantitative.

Example 9

The method of Example 8 was repeated except that 38.6 g of the amount of tert-butanol supplied was changed. The conversion of isobutylene is 86.6%. After the reaction, the reaction mixture was allowed to settle and separated into two phases. Evaporation of the remaining hydrocarbon mixture on the upper layer at atmospheric pressure gave 13.1 g of concentrated aqueous tert-butanol solution containing 90.1% by weight of tet-butanol and 8.9% by weight of water. The lower layer contains 39.6 g of tert-butanol and the selectivity of isobutylene to tert-butanol is almost quantitative.

Example 10

Into a 300 ml stainless steel autoclave, 8.0 g of isobutylene, 12.0 g of 1-butene, and 97 g of 12-molybdophosphoric acid having an atomic ratio of 1:12 of P: Mo, 97 g of water, and 56 g of tert-butanol were added thereto. The mixture is stirred at 60 ° C. and 8.5 atm for 3 hours. The reaction mixture is stopped and then separated into two phases. Evaporation of the hydrocarbon mixture remaining on the upper layer at atmospheric pressure yields 9.4% concentrated tert-butanol containing 90.1% by weight of tert-butanol and 8.8% by weight of water. The lower layer contains 55.8% by weight of tert-butanol and the selectivity of isobutylene over tert-butanol is almost quantitative.

Example 11

In a 300 ml stainless steel autoclave, 8.0 g of isobutylene, 12.0 g of 1-butene, 200 g of 12- tungstophosphoric acid having an atomic ratio of 1:12 of P: Mo, 100 g of water, and 65.0 g of tert-butanol The mixture is stirred at 40 ° C. and 6.0 atm for 3 hours. The conversion of isobutylene is 83.0%. The reaction mixture thus obtained is stopped and separated into two phases. Evaporation of the remaining hydrocarbon mixture on the upper layer at atmospheric pressure yields 9.1 g of concentrated tert-butanol containing 90.2% by weight of tert-butanol and 8.8% by weight of water. The lower layer contains tert-butanol 65.5 and the selectivity of isobutylene to tert-butanol is almost quantitative.

Example 12

The apparatus as shown in FIG. 3 was used in this example. Containing 40.0% by weight of isobutylene, 31.2% by weight of 1-butene, 17.32% by weight of 2-butene, 13.75% by weight of butane, 0.1% by weight of propane, 0.1% by weight of pentane and 0.4% by weight of butadiene The waste BB fractionation is fed via line 8 to the bottom of 10 l reactor III at a rate of 200 g / hr, at the same time 17.2% by weight of tert-butanol, 27.6% by weight of water and Si to W atomic ratio 1:12. The recycle liquid constituting 55.2% of 12- tungstosilic acid having an is fed to the bottom of reactor (III) in decanter (IV) via line (10), the mixture being 40 ° C., 6.0 in reactor (III). Stir thoroughly at atm. The reaction mixture solution is transferred to a decanter (IV) with temperature and pressure maintained at 40 ° C. and 6.0 atm respectively and the reaction mixture is separated into two phases. The upper phase in the decanter (IV) is fed to the evaporator (V) at a temperature and pressure of 30 ° C. and atmospheric pressure, respectively, at a rate of 233.4 g / hr, and the remaining hydrocarbon mixture is passed through line 12 to the evaporator (V). At the rate of 128 g / hr. On the other hand, the concentrated tert-butanol aqueous solution is collected through the line 13 at the bottom of the evaporator V at a rate of 105 g / hr.

The lower bed in decanter (IV) is fed to the bottom of reactor (III) through line (7) and exits the reaction system at a rate of 32.5 g / hr corresponding to the reduced amount of water in the reaction. The apparatus used is made of stainless steel (SUS 27).

Example 13

12.8 g of isobutylene, 19.2 g of 1-butene, an atomic ratio of Si to W 1: 12, 120 g of 12-tungstosilic acid, 32 g of sodium sulfate, 32 g of tert-buta, in a 300 ml stainless steel (SUS 27) autoclave 12 g of phenol and 160 g of water were added thereto, and the mixture was stirred at 60 ° C. and 8.5 atm for 7 hours.

The conversion of isobutylene is 77.8%. The reaction mixture thus obtained is separated into two phases upon standing, and the concentrated tert-butanol aqueous solution containing 88.9% by weight of tert-butanol and 10.1% by weight when the hydrocarbon mixture remaining on the upper layer is evaporated at atmospheric pressure. 14.7 g was obtained. On the other hand, 12.1 g of tert-butanol was recovered on the lower layer and the selectivity of isobutylene to tert-butanol was almost quantitative.

Example 14

The method of Example 13 was repeated except that inorganic acid salts as shown in Table 4 were used instead of lithium sulfate and the reaction termination time as shown in Table 4 was used. The selectivity of isobutylene over tert-butanol is almost quantitative and the results are shown in Table 4.

TABLE 4

Example 15

The apparatus as shown in FIG. 3 was used in this example. The same hydrocarbon mixture as in Example 12 was fed via line 8 to the bottom of reactor III at a rate of 600 g / hr and at the same time having a water weight of 54.1%, an atomic ratio of Si to W 1: 12 A recycle mixture consisting of 20.3% by weight of tungstosilic acid, 21.7% by weight of sulfuric acid and 3.9% by weight of tert-butanol is fed from the decanter (IV) via line (10) and line (7) The added water through is fed to the bottom of the reactor (III) at a rate of 2955 g / hr. In reactor (III) the mixture is transferred to a decanter (IV) maintained at 50 ° C., 7.0 atm.

The upper phase in the decanter (IV) is fed to an evaporator (V) maintained at 30 ° C. and atmospheric pressure, and the remaining hydrocarbon mixture is concentrated tert-buta containing 89% by weight of tert-butanol and 10% by weight of water. The knol aqueous solution is withdrawn at the rate of 385 g / hr at the top of the evaporator V via line 12 while the knol aqueous solution is withdrawn at the rate of 318 g / hr at the bottom of evaporator V via line 13. The lower bed in decanter (IV) is recycled to the bottom of reactor (III) via line (10) and water is passed through reactor (III) through line (7) at a rate of 100 g / hr corresponding to the reduced amount in the reaction. Is fed to the bottom of the chamber and exits the reaction system. The apparatus used is made of stainless steel (SUS 27).

Claims (1)

A hydrocarbon mixture comprising isobutylene and n-butene is contacted with a solution containing a heteropolyacid having at least one condensation coordination atom selected from the group consisting of Mo, W and V at a temperature of up to 100 ° C. A process for preparing tert-butanol by selective hydration of a butylene mixture.

Images