JPS647054B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a novel method for producing sec-butanol (SBA). SBA can be used as a solvent or converted by dehydrogenation to methyl ethyl ketone by known methods. (Prior Art) Conventionally, as a method for producing SBA, a method of synthesizing SBA from n-butene using sulfuric acid as a reaction medium (catalyst) is generally known. However, this method has many problems, such as corrosion of equipment materials, a large amount of thermal energy required to separate the product from the catalyst, and environmental pollution. Further, even if phosphoric acid, heteropolyacid, and water-soluble metal salts thereof are used as catalysts, they cannot escape from the same problems as sulfuric acid because they are water-soluble catalysts. In this regard, if a solid catalyst is used, the reaction product of the catalyst and the aqueous phase can be easily separated. For these reasons, many methods using solid catalysts have been proposed. However, even when these catalysts are used, relatively high temperatures and pressures are required, or a large amount of water is required. The equilibrium in this hydration reaction favors the production of SBA at low temperatures and high pressures, and even if the reaction is carried out under the above conditions, the SBA concentration in the effluent is quite low and a large capacity reactor is required. Also, several recirculations are necessary to obtain sufficient n-butene conversion. As described above, recycling a large amount of n-butene and water poses a problem in terms of thermal energy. On the other hand, the styrene-divinylbenzene copolymer with sulfonic acid groups
Although it is said to have relatively high catalytic activity for hydration even at relatively low temperatures of 100 to 130°C, the SBA concentration in the effluent is still low. In the hydration of n-butene, recycling the SBA-containing aqueous product is not a desirable method due to its detrimental effect on the reaction equilibrium. On the other hand, raising the reaction temperature to a higher temperature in order to further increase the reaction rate has the disadvantage that the sulfonic acid group is gradually eliminated and deactivated, and as described above, this is disadvantageous in terms of equilibrium. The use of solvents has been proposed as a way to increase the reaction rate at low temperatures, but this has not yet been effective enough to offset the disadvantages of using solvents in terms of separation process and thermal energy. . (Problems to be Solved) As a result of extensive research in order to solve the various problems described above, the present inventors have discovered that butane containing n-butene can be used using strongly acidic ion exchange resin or aluminosilicate as a catalyst. -Butene fraction (B-
By reacting B) with an alkylene glycol (AG) having 2 to 4 carbon atoms, alkylene glycol mono- and/or di-sec-butyl ether (ether) can be synthesized in a higher yield than SBA produced by the reaction of n-butene and water. discovered that by hydrolyzing the ether in the presence of the same catalyst and B-B as used in the synthesis reaction, it was possible to eliminate the drawbacks of the conventional method and produce highly concentrated SBA at a high reaction rate, and completed the present invention. did. Therefore, it is an object of the present invention to provide a process for producing SBA that does not involve equipment corrosion problems such as those caused by the use of sulfuric acid, and which is free from the risk of pollution caused by the use of sulfuric acid or heteropolyacids. Another purpose is to use solid catalysts to achieve high reaction rates and high concentrations of SBA.
This provides an easy method for obtaining high selectivity and low energy consumption. (Means for Solving the Problems) That is, the gist of the present invention is to combine a butane-butene fraction containing n-butene and an alkylene glycol having 2 to 4 carbon atoms using a strongly acidic ion exchange resin catalyst or an aluminosilicate catalyst. react in the presence of
Alkylene glycol mono- and/or di-
Sec-butyl ether is synthesized, and the ether is mixed with a compound of 0.2 to 10
The present invention consists in a method for producing sec-butanol, which comprises hydrolyzing the ether using 1 to 10 times the mole of water in the presence of a butane-butene fraction that is twice the weight of the ether. The reaction in the present invention is expressed by the following formula. Here, R is -C _o H _2o - and n is 2-4.
As R, -CH ₂ CH ₂ - is preferable from the viewpoint of cost and reactivity. CH ₃ CH ₂ CH＝CH ₂ +HOROH →CH ₃ CH ₂ (CH ₃ )CHOROH (1) CH ₃ CH ₂ (CH ₃ )CHOROH＋H ₂ O →CH ₃ CH ₂ CH(OH)CH ₃ +HOROH (2) CH ₃ CH ₂ CH(OH)CH ₃ →CH ₃ CH=CHCH ₃ +H ₂ O (3) Although the formula is shown for mono-sec-butyl ether (MBE), di-sec-butyl ether (MBE) produced by the reaction of MBE and n-butene Butyl ether (DBE) is also hydrolyzed to SBA and MBE. To be more specific, the usual method is to suppress the reaction of formula (3) and obtain a large amount of SBA by extremely increasing the amount of water supplied, but in this case,
Although an improvement in the conversion rate was observed, the
The concentration of SBA decreases. Therefore, this poses a problem in terms of separation and purification of SBA. Therefore, high purity is extracted from the product.
To separate and purify SBA easily and at low cost
In the reaction of formula (2), by coexisting B-B, the amount of water supplied to the ether is suppressed, resulting in an increase in the reverse reaction of formula (1) and the decomposition reaction of SBA shown in formula (3). n-butene dimer (DNB) by suppressing the
We discovered that water and AG can be easily separated from the product by adjusting the amount of produced and applying the ternary azeotrope of DNB-SBA-water.
The invention has been completed. In the present invention, examples of strongly acidic cation exchange resins that can be used as catalysts include styrene sulfonic acid type cation exchange resins (sulfonated crosslinked copolymers of styrene and polyunsaturated compounds such as divinylbenzene). ), phenolsulfonic acid type cation exchange resin (phenolsulfonic acid condensed with formaldehyde), sulfonated coal, sulfonated asphalt, sulfonic acid type cation exchange resin with sulfonic acid group bonded to fluororesin (For example, Nafion manufactured by DuPont) etc. have a sulfonic acid group. Heat resistance can be imparted to these resins by introducing electron-withdrawing groups such as bromine, and sufficient activity can be maintained for a long period of time even at the reaction temperature in the present invention. On the other hand, aluminosilicate catalysts are generally A type,
Zeolite, Y-type zeolite, erionite, offretite, mordenite, and pentasil-type zeolite with a high silica/alumina ratio are well known, and any of them can be used in the present invention.
In particular, synthetic mordenite with a silica/alumina ratio of about 15 to 23 is effective. Next, in the present invention, the butane-butene fraction containing n-butene used in the ether synthesis step and the hydrolysis step may be n-butene alone or a mixture with butanes, and the concentration of n-butene may be extremely high. There are no restrictions unless the value is low. Further, it is not necessary to use the same composition in the synthesis step and the hydrolysis step, and for example, the roughinate B-B after the synthesis reaction can be used in the hydrolysis step. In addition, even if isobutene is included, it is possible to react as is, but ethylene glycol-tert-butyl ether, tert-butanol, and isobutene dimer are generated simultaneously, making the product separation process somewhat complicated. When a large amount of isobutene is contained, it is more preferable to lower the isobutene concentration by a commonly known method. Also, AG does not need to be of high purity.
It may contain dialkylene glycol (DAG), which is a dehydrated condensation product of AG, water, or ether. When AG contains a small amount of water, it has the effect of suppressing the formation of DAG, although the conversion rate decreases slightly. Ether, which is a raw material for hydrolysis reaction, is also AG.
Similarly, it is also possible to use a product containing a small amount of AG, etc., obtained by liquid-liquid separation of the effluent of the synthesis reaction. The reaction may be carried out in any commonly used manner, such as a fixed bed flow system (upward flow, downward flow, countercurrent), fluidized bed (moving bed) system, stirred batch system, or continuous system. The reaction temperature for both synthesis reaction and hydration reaction is
100 to 250°C, and when using an ion exchange resin as a catalyst, 100 to 160°C, preferably 120 to 160°C
It is preferable to set the reaction temperature to .degree. C.; at low temperatures, a sufficient reaction rate cannot be obtained, and at high temperatures, the selectivity of the target product decreases and the activity of the catalyst also decreases.
When using an aluminosilicate catalyst
The temperature is preferably 150 to 250°C, preferably 150 to 200°C; at low temperatures, a sufficient reaction rate cannot be obtained, and at high temperatures, the selectivity of the target product decreases. The reaction pressure is preferably such that B-B can maintain a liquid phase at the reaction temperature. The temperature and pressure in the separation tank for separating the reaction effluent into two layers can be selected widely without being limited by the reaction conditions, within a range where B-B does not become a gas phase. The molar ratio of n-butene to AG in the synthesis process and ether to water in the hydrolysis process can be selected within a wide range, but if AG or water is in excess, the concentration of ether and SBA in the reaction effluent will be low. This is disadvantageous in terms of separation and heat costs. On the other hand, if AG or water is too low, there is a risk that more DNB will be produced than necessary. Therefore, the AG/n-butene molar ratio is preferably 0.5 to 10, and the water/ether molar ratio is preferably 1 to 10. The amount of B-B to be supplied in the hydrolysis step can be selected within a wide range, but an effective amount is 0.2 to 10 times, preferably 0.5 to 3 times, the weight of the raw material ether. Even if a large amount of B-B is supplied, no particularly good effect is obtained, and the increase in the amount of B-B recirculated becomes disadvantageous in terms of heat costs. In the case of a flow type, LHSV is preferably 0.05 to 10 hr ^-1 . The present invention will be described below with reference to the drawings.
This figure is a flowchart showing an example of the SBA manufacturing process of the present invention. However, this does not limit the present invention. In the following,
Alkylene glycol (AG) will be explained using ethylene glycol (EG), which is a preferred specific example thereof. B-B from conduit 1 and EG from conduit 2 are fed to synthesis reaction tower A through conduit 3, and the reaction product containing ether is introduced into debutanizer B through conduit 4.
Here, the roughinate B-B is discharged from the system through conduit 5, and the remaining components are introduced into distillation column C through conduits 6 and 7 to separate unreacted EG. EG extracted from conduit 9 is sent to distillation column J, where a small amount of diethylene glycol (DEG) is separated and removed through conduit 26, and EG is extracted from conduit 25 to replenish the loss from conduit 27. It joins the new EG and is recycled to conduit 2. In this step, before being introduced into the debutanizer B, a process of liquid-liquid separation into an upper layer containing B-B as a main component and a lower layer containing EG as a main component can also be used. The ether distilled from the top of the distillation column C through conduit 8 is mixed with B-B from conduit 24 and passed through conduit 10, and further mixed with water and recycled ether sent from conduit 22 and passed through conduit 21. is supplied to the hydrolysis reaction tower D. The effluent containing the reaction product SBA and a small amount of DNB is sent via conduit 11 to separation tank E, where B-B is the main component and most of SBA, unreacted ether and
Upper layer containing DNB and a small amount of MBE in water and EG;
Separate into lower layer containing SBA. If the hydrolysis reaction is carried out in countercurrent, liquid-liquid separation can be achieved in the reaction tower, and all the reactions mentioned above are equilibrium reactions, so
It has the advantage that the reaction can be carried out while shifting the equilibrium. However, each supply speed may be limited due to operational aspects such as flooding. The lower flow, mainly consisting of EG and water, passes through conduit 12 and joins with the reactants from the synthesis step from conduit 6, passes through conduit 7 as described above, and enters distillation column C, where EG is separated as described above. The upper stream mainly composed of B-B is introduced into the flashing column F through a conduit 13, and B-B is separated from the top of the column through a conduit 14. This B-B
It contains n-butene partially produced by the decomposition reaction, and the butene concentration is higher than that of supply B-B, so it is mixed with a predetermined new supply B-B (conduit 23),
A predetermined amount is supplied to the synthesis reaction tower A through the conduit 1, and the remainder is recycled to the hydrolysis reaction tower D through the aforementioned conduit 24. The bottom liquid of the flashing column F is introduced into the dehydration column G through a conduit 15. Conduit 1 from the top of dehydration tower G
6, the azeotrope of DNB-SBA-water is distilled out, and a decanter H separates and removes water as a lower layer through a conduit 18, and DNB as an upper layer through a conduit 29. A part of the upper layer of the decanter H can be refluxed to the dehydration tower to adjust the component composition of the three-component azeotrope within the dehydration tower, or can be returned to the inlet of the dehydration tower. The bottom liquid of dehydration tower G is sent to SBA tower I through conduit 17, and highly purified SBA is obtained through conduit 19 through distillation. The unreacted ether separated by distillation is recycled to hydrolysis reactor D via conduits 20 and 22. On the way, water from the lower layer of the decanter H sent through the conduit 18 is joined to the conduit 20, and new water is further supplied from the conduit 28 to supplement the consumed amount. (Effects of the Invention) The reaction of the present invention can produce SBA at high concentrations without the fear of equipment corrosion or pollution.
You can get SBA. (Example) The method of the present invention will be specifically explained with reference to Examples below. Example 1 A stainless steel reaction tube with an inner diameter of 28 mm and a length of 1500 mm was filled with 800 c.c. of Amberlite 200 (manufactured by Rohm and Haas) as a catalyst. At the molar ratio of B-B to n-butene in the composition shown in Table 1,
4.6 times the amount of EG was supplied at LHSV0.2hr ^-1 , 130℃,
When the reaction was carried out at 50 kg/cm ² , B-B having the composition shown in Table 2 and a reaction product having the composition shown in Table 3 flowed out. The n-butene conversion rate at this time was 78 mol%.

【table】

【table】

[Table] Example 2 EG/n-butene molar ratio is 2.7, LHSV is
The same conditions as in Example 1 were used except that the temperature was changed to 0.8 hr ^-1 . The n-butene conversion rate at this time was 46 mol%,
The MBE selectivity (based on n-butene) was 93 mol%. Example 3 Reaction temperature: 120°C, pressure: 40Kg/cm ² , LHSV:
The same conditions as in Example 2 were used except that the temperature was changed to 0.3 hr ^-1 . The composition of the reaction effluent from which B-B was removed is shown in Table 4. n-butene conversion rate is 61%, MBE selectivity is
It was 93%.

[Table] Example 4 The same conditions as in Example 3 were conducted except that synthetic mordenite (TSZ-640 manufactured by Toyo Soda Kogyo Co., Ltd.) having a silica/alumina ratio of 19 was used and the temperature was 170°C. The n-butene conversion rate was 32% and the MBE selectivity was 91%. Example 5 20 c.c. of Amberlite 200, 12 g of MBE (purity 98.5%), and 7 ml of water in an autoclave with an internal volume of 200 ml.
28g of B-B containing 61wt% of n-butene was charged and reacted at 150°C and 50Kg/ ^cm2 for 2 hours, resulting in an MBE conversion of 56%, a selectivity based on n-butene of SBA73%, and DNB21. It was %. The SBA concentration in the liquid component from which B-B was removed from this reaction product was 13 wt%. Comparative Example 1 The same conditions as in Example 5 were carried out except that B-B was not added. MBE conversion rate is 83%, SBA selection rate is
The DNB selectivity was 1%, and the SBA concentration in the reaction solution components was 3%. Example 6 Heat-resistant ion exchange resin EX-146 (manufactured by Mitsubishi Chemical Industries, Ltd.) was placed in a flow-through reaction tube with an inner diameter of 28 mm and a length of 1500 mm.
ml filled. 60 ether of the composition shown in Table 5
g/hr, 138 B-B containing 65% n-butene
water was supplied from the bottom of the reaction tube at a rate of 23 g/hr, and the reaction was carried out at 147° C. and 40 Kg/cm ² . The ether conversion rate was 57% and the SBA selectivity was 70%. The reaction effluent composition was as shown in Table 6. Furthermore, the n-butene concentration in B-B increased by about 1%.

【table】

[Table] The reaction effluent was separated into two upper and lower tanks in a separation tank under the same temperature and pressure. As a result, the distribution ratio of each component to the upper layer was as shown in Table 7.

[Table] B-B is evaporated and separated from this upper layer component, water and DNB are separated by azeotropic distillation, and then 99
% purity of SBA was obtained by distillation operation. Example 7 Raw material supply amount: ether 140g/hr, B-B83
The reaction was carried out under the same conditions as in Example 6 except that the amount of water was 36 g/hr. Ether conversion rate is 49%, selectivity is based on n-butene: SBA54%, DNB10%, n
- 36% butene. Example 8 Raw material supply amount: ether 335g/hr, B-B150
The reaction was carried out under the same conditions as in Example 7 except that the amount of water was 60 g/hr. The ether conversion rate was 29%, and the selectivity was 66% for SBA, 9% for DNB, and 25% for n-butene. Comparative Example 2 A reaction was carried out under the same conditions as in Example 8, except that the raw material supply amount was 61 g/hr of B-B and 29 g/hr of water, and no ether was supplied. The conversion rate of n-butene is
It was 7.2 mol%, and the SBA selectivity was 69%.
Furthermore, the SBA concentration in the reaction effluent from which B-B was removed was 4.9 wt%. Example 9 Particle size 2-5 mm in a reaction tube with an inner diameter of 28 mm and a length of 700 mm
Ion exchange resin (provided by OMZ-17 Organo)
Filled with 300ml, MBE23g/hr and B-B38g/hr
was supplied from the lower part of the reaction tube, and 6 g/hr of water was supplied from the upper part, and the reaction was carried out at 40 Kg/cm ² and 130°C. By maintaining the two-liquid interface in the reaction tube constant, liquids having the composition ratios shown in Tables 8 and 9 flowed out from the upper and lower parts, respectively. However, B-B was separated by evaporation. The ether conversion rate was 20% and the SBA selectivity was 72%.

【table】

【table】

[Table] Example 10 The same procedure as Example 9 was carried out except that Zeolon 900H (manufactured by Nikka Seiko) was used as a catalyst and all raw materials were supplied from the bottom of the reaction tube at 180°C and 50Kg/cm ² . . MBE conversion rate is 20%, selectivity is SBA 56%,
DNB was 27%. Example 11 Example 10 except that the same synthetic mordenite as in Example 4 was used as a catalyst and the reaction temperature was 170°C.
I did it in the same way. The MBE conversion rate was 42%, and the selectivity was SBA 52% and DNB 23%.

[Brief explanation of the drawing]

FIG. 1 is a flow chart of an example of the method of the present invention. A...Synthesis reaction tower, B...Debutanizer, C...
Distillation tower, D...hydrolysis reaction tower, E...separation layer,
F...Flush tower, G...Dehydration tower, H...Decanter, I...SBA tower, J...Distillation tower, 5...
Roughinate B-B, 19...SBA, 23...
Supply B-B, 26...DEG, 27...EG, 28
...Wed, 29...DNB.

Claims (1)

[Scope of Claims] 1 A butane-butene fraction containing n-butene and an alkylene glycol having 2 to 4 carbon atoms are reacted in the presence of a strongly acidic ion exchange resin catalyst or an aluminosilicate catalyst to form alkylene glycol mono and /or Di-sec-butyl ether is synthesized, and the ether is treated in the presence of a strongly acidic ion exchange resin catalyst or an aluminosilicate catalyst, and in the presence of a butane-butene fraction in an amount of 0.2 to 10 times the weight of the ether. A method for producing sec-butanol, which comprises hydrolyzing ether using 1 to 10 times the mole of water. 2. By carrying out the hydrolysis reaction of the ether in countercurrent flow, a lower flow containing most of the alkylene glycol and mainly composed of water, sec-butanol,
2. The production method according to claim 1, wherein the by-product butene dimer and an upper stream containing a large portion of unreacted ether are separated into an upper stream containing a butane-butene fraction as a main component. 3. By separating the hydrolysis reaction product of the ether into liquid-liquid in a separation tank, a lower stream containing most of the alkylene glycol and mainly composed of water,
2. The production method according to claim 1, wherein the process is divided into an upper stream containing a large portion of sec-butanol, by-produced butene dimer, and unreacted ether, and whose main component is a butane-butene fraction. 4. After removing the butane-butene fraction from the upper stream, the small amount of water contained is distilled and separated by a three-component azeotrope of by-product butene dimer, sec-butanol, and water. Range 2nd
The manufacturing method described in Section 3 or Section 3. 5. The production method according to any one of claims 1 to 4, wherein the alkylene glycol is ethylene glycol.