DE2459103A1 - CATALYST FOR THE HYDRATION OF OLEFINS, AND THEIR PRODUCTION AND USE - Google Patents

Description

Patent attorneys

Dr. Ing.v / dtsr Abitz
Dr. CL lor F.'Morf
Dr. Hans-A. Browns

3 fa won CTi - ^ ₁ ii ^. ^ ÜVKiua / str. 24

Dec. 13-1974

433 168

NATIONAL DISTILLERS AND CHEMICAL CORPORATION New York, N.Y. 10016, V.St.A.

Catalyst for the hydration of olefins and their production and use

The use of glass as a support for catalysts is in many reports in technical literature. For example, Uemaki et al. (Chemical Abstracts, 74: 75964 and 73: 3408) glass beads as a solid diluent for a kieselguhr catalyst impregnated with phosphoric acid. The use of glass or quartz as opposed to porous glass or glass beads as a carrier for Η, ΡΟ. for the production of a catalyst is by Langlois and coworkers in "Petroleum Refiner", Volume 31, No. 8, 1952, as well as in the FR-PS 1 294 712 described. The use of porous glass as a support for catalysts other than hydration are determined by olefins is described in PR-PS 1,492,495 and DT-OS 1,814,253. The use of non-porous Glass or glass beads as a catalyst carrier is known from many publications, including US Pat. No. 2,847,475. and the R-PS 48 909, known.

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It has now been found that an improved catalyst for the hydration of olefins using a high silica, porous glass bead carrier with special structural and surface properties produced v / ground can. The glass beads soaked with phosphoric acid form an effective catalyst and have a high compressive strength.

The invention relates to a catalyst for the hydration of olefins, which is made from silicon dioxide-rich, porous glass beads with special structural and surface features.

According to a preferred embodiment of the invention silicon dioxide-rich glass beads, which have certain structural and surface features, soaked with aqueous phosphoric acid, and the catalyst obtained in this way is in quiescent bed used for vapor phase hydration of olefins.

The catalyst support consists of silicon dioxide-rich porous glass beads, which are characterized by the following properties mark:

Particle size and shape: particles, preferably spherical Shape, with Martin diameters from 0.5 to 25.0 mm, preferably from 2.0 to 4.8 mm. (The Martin diameter is the distance between opposite sides of the particle, across the particle and on a line that bisects the projected area, measured); See Martin et al., Transactions of the Ceramic Society (Eng.), Volume 23, 1924, page 61.

Pore volume 0.4-1.0 cnr / g> preferably

0.5-0.80 cm

Mean pore diameter 30-1000 $ bulk density 0.5-0.8 g / cm ⁵

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Average compressive strength more than 4.54 kg (50 particles)

Expansion coefficient 0.5-0.8 χ 10 "(0-300 ° C) '

Specific surface area (BET) 50-300 m ² / b

Composition: SiOp more than 95 Y °

less than $ 0.02 ₂ - less than $ 1 Pe ₂ O ^ less than 1 f £

Y7 heat resistant at temperatures up to 1000 ° C.

Against attack by aqueous phosphoric acid at concentrations Chemically resistant up to 70 percent by weight at temperatures up to 270 ° C for a period of up to 1000 hours and mechanically resistant.

The mean compressive strength of the glass beads is determined with the Chatillon tablet strength tester, which the Measures the minimum force required to crush a particle between parallel plates.

Suitable glass beads are commercially available. An example of this are the "Type 1C2" porous glass beads manufactured by the Pittsburgh Plate Glass Company. Otherwise, such microporous glass catalyst supports can also be made by known methods, e.g. the process of DT-OS 2 309 449, · produced will. '...

Porous glass is made by heat treating a certain type of glass until a micro-phase separation occurs into a silica-rich microphase and a second, leachable Micro phase takes place, after which one cools the mass and then leaches the leachable phase, so that one mainly A porous structure consisting of silicon dioxide remains. One such glass is an alkali borosilicate glass, 'bei which the micro-phases from a silicon dioxide-rich phase and

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433 168 η

The latter can be leached with mineral acid, leaving a porous structure of silicon dioxide. An example of such a glass is unmelted "Vycor" glass (manufactured by the Corning Glass Company) porous glass, which has been made from "Yycor" (Vycor designation 7930), there is chemically to 96 tso of silica, 3 to i ° of boron oxide and 0.5 i "of R ₂ O, RO ₂ + (mainly Al ₂ O, + and contains traces of Ha ₂ O and As ₂ O-.

The process for making high silica porous glass was first described by Nordberg in "Journal of the American Ceramic Society ", Vol. 27, 1944, pp. 299-305. Russian researchers (Zhdanov et al.," Chemical Abstracts ", 58: 8743) have shown that the pore volume of porous glasses depends on the alkali oxide content of the original Glass and depends on the respective alkali metal. The pore size, i.e. the pore diameter, can be determined by the temperature and duration of the heat pretreatment within a few angstroms being controlled; See Dobychin et al, Chemical Abstracts, 60: 14228 (1964).

The glass beads used according to the invention as a catalyst carrier must have a high porosity because they contain a substantial amount of aqueous H ^ PO. included and still one must have a dry surface. Neither of these two conditions is met if the glass is non-porous. The essential The amount of aqueous phosphoric acid for a given particle volume or size is for a high one catalytic activity required, while the dry state is required to attack the reactor walls to be avoided by phosphoric acid if the catalyst is in contact with the walls. If porous glass beads having the above Have properties, incomplete with Η, ΡΟ. of high Concentration are saturated, the set conditions are met.

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In the hydration reaction, phosphoric acid comes out of the catalyst "lost. It is believed to be in the pores a reaction between ethylene and phosphoric acid takes place with the formation of a volatile but heat-unstable ethyl phosphate. Part of this compound evaporates from the pores before decomposing to form phosphoric acid and ethylene or a reaction with water to form alcohol and phosphoric acid takes place. This allows phosphoric acid to escape from the pores. The same reaction can also take place outside the pores, where the high linear gas flow velocity allows much faster movement before decomposition or reaction occurs. This process continues continued until the acid emerges from the reactor.

When the glass bead carrier is soaked in phosphoric acid, it is obtained a catalyst for the hydration of olefins. The impregnation can be done by filling a vessel containing aqueous phosphoric acid with the pearls, or by a vessel containing the pearls is charged with phosphoric acid. The vessel in which the pearls are soaked can be useful will be the olefin hydration reactor itself. So much acid is used that the pearls are covered with acid The pearls are left to soak in the acid for a sufficient period of time, after which the acid is left to soak expires. The impregnation process can be repeated one or more times. But you can also use the H ^ PO. Solution Spray into the glass beads in the form of very small droplets from 0.001 to 0.005 mm in size until the carrier is saturated is. At this point in time, the phosphoric acid content, determined as a kilogram of 100 percent H-zPO, is in springs ηγ des. The catalyst contained is solid. The soaked porous glass beads can then be suitably used, for example by a heated circulating gas such as nitrogen or ethylene, at increased Temperature are dried so that the dry catalyst is obtained.

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The Η, ΡΟ, used to soak the glass beads, is used as an aqueous solution, their orthophosphoric acid concentration in the range from $ 12 to $ 85, preferably from about $ 50 to $ 60, lies. The soaking can take place at temperatures of 20 to 200 ° G, but is preferably in the temperature range of about 25 to 50 C. Usually the pearls are left alone 15 minutes to 5 hours or longer, preferably about 2 hours, soak in the acid. Longer treatment times can also be used use; however, this is generally unnecessary. Then the excess liquid acid is usually left Expire 0.5 to 2 hours. The aqueous solvent for the phosphoric acid can optionally be ethanol and / or contain a small percentage of a wetting agent such as polyoxyethylene to pull the pores of the glass beads with acid to facilitate.

The drying of the soaked glass beads can be any suitable Be done in a manner; however, it is preferred to operate at least partially with a suitable gas stream, such as nitrogen or ethylene, the heat being supplied to the reactor either from outside or through the preheated gas. The latter procedure is preferred. For example, the soaked pearls can last for 3 to 24 hours, preferably 10 to 15 hours Hours, in the air and then 1 to 4 hours, preferably about 2 hours, at temperatures of 100 to 200 0, preferably of about 110 ° C, to be dried in the oven.

The extent of drying is controlled in such a way that not the whole pore volume of the beads is occupied by the H ^ PO, ie that the carrier is not completely saturated. The volume occupied by the acid is less than $ 100, preferably about $ 40 to $ 85 of the total pore volume. The degree of saturation will vary depending on the concentration of acid in the pores and the strength of the HvPOi solution used for soaking. If, for example 55 percent acid is used, preferably about 70 to i 'of the pore volume after the

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Drying be filled _{with H 7} PO _4. Since the support is not saturated, practically all of the acid is inside the pores, so that the surface remains dry and corrosion of the walls of the olefin hydration reactor is avoided.

The supported catalyst according to the invention is used to Hydrate olefins to alcohols and ethers. The catalyst can be used in all known processes of this type and is particularly suitable for converting monoolefins with 2 to 10 carbon atoms, such as ethylene and propylene and butylene. The catalyst is particularly suitable for the hydration of ethylene to ethanol and diethyl ether. The hydration reaction is generally carried out » by making a gaseous mixture of olefin and water continuously at elevated temperatures and pressures with the catalyst brings in touch. This method is known per se and does not need to be described in detail here will.

In the preferred continuous vapor phase hydration process one works with reaction temperatures of 235-350 ° C, preferably 245-300 ° C, pressures of 35-105 kg / cm, preferably 61-85 atm, molar ratios of water to ethylene of 0.4-2.0, preferably 0.5-0.8, and Steam speeds from 5-100, preferably from 15-35 Hm / min / m (normal cubic meters per minute per cubic meter of catalyst; Normal conditions are 1 at and 15 ° G). Orthophosphoric acid solution is fed to the reactor at the same rate as it is lost from the reactor.

The catalyst according to the invention is characterized by an average compressive strength (50 particles) of more than 4.54 kg, a phosphoric acid content of 30-1008, preferably from 48-480 and especially from 160-480 kg / m of catalyst and a high degree of activity for the hydration of olefins to alcohols and ethers. The catalyst is suitable in

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primarily for use in resting bulk, but can also. can be used as a moving bed.

In the following examples, parts and percentages are based on weight.

example 1

228.6 g (375 ml) high silica porous glass beads (type 1C-2 Pittsburgh Plate Glass Company), which have the following characteristics:

Pore volume 0.6 cm / g

Pore diameter 800-1000 S

Particle shape and size

roughly spherical with central Martin diameter of 3.3 mm

3 density 0.6 g / cm

are 2 hours at room temperature (23 ° 0) in 55 percent aqueous H ^ PO. immersed, then drained and dried at 105 ° C for 3 hours. The mean compressive strength of the catalyst obtained in this way (based on 50 particles) is 6.35 kg, with 0 tfo of the particles having a compressive strength of <0.9 kg, and the free phosphoric acid content is 27.93 °, corresponding to 282 kg each no catalyst.

300 ml (302.9 g) of this catalyst are placed in a steel jacketed reactor 35.5 cm long and 4.1 cm clear width entered. After charging the catalyst, the reactor is closed and the oil is heated to 264 ° C circulated through the jacket to heat the catalyst. When the temperature of the catalyst layer reaches .236 ° C, a vaporous mixture of ethylene and water is passed in a molar ratio of water to ethylene of 0.558 down through the catalyst with a steam speed of 30.14 Nm / min / m catalyst under a pressure of 68 atm. The converted gaseous effluent flows through a pneumatically • operated valve that controls the reaction pressure and through

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that the pressure of the outflowing gas relaxes to atmospheric pressure will. ■

A reaction takes place and a steady state is reached "in which the catalyst temperatures at the upper and lower ends of the catalyst bed are 265 and 271 ° C., respectively, while the pressure is 68 atmospheres. In order to increase the activity of the catalyst under the conditions of the To measure the steady state, the outflowing gas is diverted for exactly one hour to collect data via a special path The uncondensed gas is passed through a scrubbing tower through which liquid methanol trickles down in countercurrent to the gas to wash out the ethanol and the ether. These two compounds are determined in the methanol scrubbing liquid by gas-liquid chromatography and also obtained by distillation. The volume of the ethylene flowing out is measured The content of the condensed aqueous phase is also determined by gas-liquid chromatography, whereupon the products are recovered by distillation. The following results are obtained after 35 hours: The space-time yield of alcohol is 167, that of ether is 33.3 liters (at 20 ° C.) per m ^{5 of} catalyst per hour. The degrees of conversion of ethylene to ethanol and ether are 5.83 and 1.31 ^ respectively.

Example 2 .

228 g (275 ml) high silica porous glass beads (Type 1C-1 Pittsburgh Plate Glass Company), which have the following characteristics:

Pore volume x 0.6 cm / g

Average pore diameter 100-125 S.

Particle size and shape

coarse, spherical with medium. *

rera Martin diameter of 4 »8 mm

Density 0.6 g / cm x ⁵

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are 3.5 hours at room temperature (23 ° G) in 55 percent aqueous phosphoric acid immersed, drain for 2 hours left and then dried at 105 ° C for 17 hours; the final Weight is 362.2 g. The analysis shows that this catalyst contains 34-, 9O # free H 1 PO- and a medium one Has a compressive strength of 13 »65 kg. The acidity is

3
speaks 340 kg BUPO. per m catalyst.

300 ml (292.9 g) of catalyst are used in the reactor according to Example 1 according to the process described in Example 1 for the continuous hydration of ethylene to ethanol in the vapor phase under the following conditions: pressure 68 atmospheres molar ratio water: ethylene = 0, 55; Vapor rate of the reactants 29.22 Nm / min / m catalyst; Inlet and outlet gas temperatures 262 and 264 C. The temperature of the catalyst at the top and bottom of the catalyst bed is 265 and 278 ° C. The results of hydration after 2 1/2 hours are a space-time yield of alcohol and ether of 164.5 or 50 l (at 20 ° C.) per π catalyst per hour with degrees of conversion of ethylene to alcohol and ether of 5.89% and 2.03 %, respectively.

example 3-

A large-scale insulated pressure reactor is filled with high silicon dioxide charged porous glass beads which have the properties described in Example 1.

55 percent aqueous H ^ PO, is pumped into the reactor until the porous glass beads are completely covered by the acid. After allowing the acid to soak in for 2 hours, the acid will drain off calmly. The catalyst has a compressive strength of more than 4.54 kg when wet or dry. The catalyst is dried by passing dry ethylene at 110 ° 0 through the catalyst bed. The one on this Improved catalyst prepared in situ is used as follows for continuous vapor phase

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433 168 M.

hydration of an olefin to the corresponding alcohol and ether used:

Ethylene preheated to 260 ° C and steam (in molar ratio Water: ethylene = about 0.6) and later circulatory

Gases are compressed to 63 kg / cm a "bs. and then passed continuously ^{downwards through the catalyst at a vapor velocity of approximately 30 Nmv m} i ⁿ / ^m catalyst, whereby it is heated to the reaction temperature The outflowing gaseous reaction mixture is cooled under pressure and the liquid mixture is separated in a high pressure separator. The vapor stream coming from the separator is fed to an alcohol scrubber, where alcohol is washed out with water, and the washed gases are via a Recycle compressor (after taking off a small stream) returned to the reactor. The washing solution is combined with the liquid phase from the high-pressure separator and fed to an ether stripping column, where the ether and other light components are removed. The ether and the remaining light components pass via an exhaust gas and finally the circulation compressor in the circuit back into the reactor.

The dilute alcohol solution withdrawn from the bottom of the ether stripping column is concentrated in a pre-rectification column and then catalytically hydrogenated in order to convert the carbonyl groups formed as a by-product into alcohol groups and to saturate the unsaturated compounds formed as by-products (e.g. to convert acrolein into n-butanol) with it they can easily be removed by distillation. That Bottom product of the pre-rectification column is circulated in the Recirculated alcohol scrubber as it consists mainly of water. After the hydrogenation, the alcohol continues through Extractive distillation and rectification purified, so that the product is continuously an alcohol of high purity receives. To the lost from the catalyst bed

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To replace phosphoric acid, one puts at the top of the same 55 percent aqueous H ^ PO, solution too.

Example 4

A catalyst is made up of 228 g (375 ml) of silica rich porous glass beads (type 1G-2) produced according to Example 1. The reactor described in Example 1 is filled with 300 ml (303 g) Catalyst charged and for the continuous catalytic vapor phase hydration of propylene with V / water to isopropanol and isopropyl ether according to a modification of the method described in Example 1 on that in quiescent bed present catalyst used.

After charging the catalyst and closing the reactor, hot oil at 202 ° C is allowed to circulate through the jacket, to heat the catalyst. When the temperature of the catalyst bed reaches 200 ° C, it becomes vaporous Mixture of propylene and water in the molar ratio of water: propylene

• 7. y.

len of 0.57 with a steam speed of 41 Nm / min / m Catalyst passed down through the catalyst at a pressure of 30 atmospheres. The converted gas flows through a pneumatic actuated valve, which controls the reaction pressure and relaxes the outflowing gas to atraospheric pressure.

During the conversion, a steady state develops in which the catalyst temperatures are at the upper and lower end of the bed are 200 or 211 ° C and the pressure is 30 atmospheres. Data collection is used to determine catalyst activity under steady state conditions outflowing gas diverted for exactly one hour via a special route. The outflowing gas is in a cooler with water cooled from 20 ° C, whereby a liquid phase condenses, which the main amount of the synthesized alcohol together with Contains water. The uncondensed gas is passed through a scrubbing tower through which liquid methanol flows in countercurrent trickles down the gas to remove the isopropanol and isopropyl

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to wash out ether. These compounds are determined in the methanol washing liquid by gas-liquid chromatography and also obtained by distillation. The volume of the propylene flowing off is measured. The isopropanol and isopropyl ether content of the condensed aqueous phase is also determined by gas-liquid chromatography, and these products are then determined by The following results are obtained after 3 hours: The space-time yield of isopropanol is 305 1 (at 20 ° C.) per m per hour. The degrees of conversion of propylene to isopropanol and isopropyl ether are 6.03 ° and 0.015? » The degree of conversion to acetone is 0.011% .

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Claims (10)

National Distillers and Chemical Corporation '433 168 Claims Catalyst for the hydration of olefins, characterized in that it consists of silicon dioxide-rich, porous glass beads impregnated with phosphoric acid, which before impregnation as particles with a Martin diameter of 0.5 to 25 mm, a pore volume of 0 »4 to 1.0 cm ^ / g, an average pore diameter of 30 to 1000 Å, a bulk density of 0.5 to 0.8 g / cm, an average compressive strength (50 particles) of more than 4.54 kg, a coefficient of expansion (0-300 ° C) from 0.5 to 0.8 χ 10 ~ ^δ , a specific surface area of 50 to 300 m / g and a silicon dioxide content of more than 95 f * , the Η, ΡΟ ^ content of the catalyst 30 to 1008. kg acid per nr catalyst and the volume occupied by the phosphoric acid as an aqueous solution is less than 100% of the pore volume of the glass beads and the catalyst has an essentially phosphoric acid-free surface. 2. Catalyst according to claim 1, characterized in that the glass beads have a Martin diameter of 2.0 to 4.8 mm exhibit. 3. Catalyst according to claim 1 or 2, characterized in that the phosphoric acid content is 48 to 480 kg of acid each m catalyst. 4. Catalyst according to claim 3, characterized in that the phosphoric acid content 160 to 480 kg acid per nr catalyst amounts to. S09829 / 082I 168, 5. Catalyst after. Claims 1 to 4, characterized in that the phosphoric acid takes up about 40 to 85 f * of the pore volume of the glass beads, "■ ■ 6 “Process for the production of catalysts according to claim 1, characterized in that silicon dioxide-rich, porous glass beads in the form of particles with a Martin diameter from 0.5 "to 25 mm, a pore volume from 0.4 to 1.0 cm / g, an average pore diameter from 30 to 1000 S, a bulk density of 0.5 to 0.8 g / cm, an average compressive strength (50 particles) of more than 4.54 kg, an expansion coefficient (0-300 C) from 0.5 to 0.8 χ 10 ", a specific surface area of ο
50 to 300 m / g and a silicon dioxide content of more than 95 f ° with a 12 to 85 percent aqueous. Phosphoric acid solution soaks and dries the soaked pearls in such a way that the acid takes up less than 100 % of the total pore volume of the pearls. 7. The method according to claim 6, characterized in that the drying is carried out in such a way that the acid takes up about 40 to 85 ίο of the total pore volume of the pearls. 8. The method according to claim 6 or 7, characterized in that that the phosphoric acid is used in the form of a 20 to 70 percent aqueous solution. 9. The method according to claim 8, characterized in that the phosphoric acid is used in the form of a 55 percent solution. 10. Use of the catalyst according to claims 1 to 5 for the 'hydration of olefins' to the corresponding alcohols. - 15 50 98 2-3 / 0 $ 20