SU1255618A1 - Method of producing cyclohexane - Google Patents

Description

one

The invention concerns a process for the preparation of cyclohexanone by the method of selective catalytic hydrogenation of phenol in the gas phase on a catalyst supported by alumina, modified with calcium, and the active component is palladium. , Dp of cyclohexanone preparation is used along with the method of oxidation of cyclohexane method g: phenol hydrogenation. While the two-step method, i.e. hydrogenation to cyclohexanone using nickel catalysts and subsequent dehydrogenation to cyclohexanone, for example on zinc modified catalysts, is of secondary technical importance; the method of producing cyclohexanone in one step competes with the method of oxidizing cyclohexane. Compared to the oxidation process, it is characterized by the formerly better material saving and a significant reduction in the formation of by-products, and also provides very pure cyclohexanone.

The effectiveness of such a selective hydrogenation process is determined by the properties of the catalyst used. In this case, only palladium catalysts on a carrier are used, differing primarily in the concentration of active components and their distribution, chemical composition, shape and texture of the carrier material, type and concentration of promoters or inhibitors added if necessary.

The known methods are carried out in a temperature range of 15-250 ° C and at a pressure of 0.05-0.3 MPa.

1GO-84 185 describes a process with a palladium catalyst on a type X zeolite base as a carrier. As parameters of the method, a temperature of 105-170 ° C is indicated, as well as a load of 0.11 v / v. The phenol conversion achieved in this process is 70% by weight of cyclohexanone in the catalyzate, which is unsatisfactory. Higher activity and selectivity are achieved with a zeolite-based papladium catalyst, such as clinosorb 4, according to DE-OS2107395,

The disadvantage of this method for its technical application is the unsatisfactory activity-time behavior. Unsatisfactory

results on selectivity and activity are obtained for the catalyst palladium-alumina at 75-150 ° C in the vapor phase (DE-AS HGF-1124487).

In DE-PS 1144267, the selectivity is improved by modifying from 0.1 to 1 wt.% Sodium in the form of sodium hydroxide or sodium carbonate. The yields of cyclohexanone above 90% by weight are achieved, however, only with a reaction time longer than 150 minutes. In addition, phenol is required with very low levels of iron, sulfur and halogens.

Methods for the selective hydrogenation of phenol in the gas phase at a temperature of 120-180 ° C are described in patents DD-51635, DD-69585 and BBB-85341.

The catalysts used contain 0.3–5 wt.% Palladium on one carrier, which contains, along with active alumina, another 10–40 wt.% Hydroxide or alkaline earth metal oxide. Under normal conditions and the good transformation of phenol, the yield of c is obtained: cyclohexanone a, up to 97-98 wt.%. The service life of the catalyst without regeneration is 3000-4500 hours and reaches a total of 15,000 hours with repeated regeneration.

The main disadvantages of these methods include: - poor molding properties of the carrier material, requiring relatively greater compression and complex process technology (a disadvantage that is not completely eliminated by molding into extrudates, proposed in DD-85341), - large bulk density of the catalyst, - different the shape and length of the extrudates, the need for additional activation with hydrogen and hydrosin treatment outside the reactor in order to improve the activity and selectivity of the catalysts, is not very flexible in terms of op edelennym harmful substances at specific initial product preparation, as well as to changes in activity and selectivity ratios for the normal aging of the catalyst throughout the entire period of operation.

DD-92243 describes a catalyst for the selective hydrogenation of phenol in a gas phase supported by spinel-type aluminum.

Disadvantages are relatively small activity and selectivity.

at high concentrations of palladium (1.8 wt.% Pd), in addition, difficulty in making types of spinel, as well as the need; carrying out - reproducing (2 additions with an alkaline solution of formalin or hydrogen with the necessary washing of chloride.

DE-OS 260 6089 describes a method for producing cyclohexanone in the gas or liquid phase at 120-220 ° C, which uses a mixture of carbonate and hydrogen phosphate of alkaline earth metals as catalyst carrier. The undesirable by-product formation up to 1.2% by weight, the special preparation of the used calcium carbonate, the formation of a mixture of the catalyst into tablets, and the high content of palladium in the catalyst are disadvantageous for this pro. Cessa.

DE-AS 2025726 describes a process for the preparation of cyclohexanone in the vapor phase at 100-150 ° C and a maximum pressure of 0.2 MPa in the presence of a catalyst, which must have palladium deposited on the peripheral surface of the granule to achieve sufficient selectivity. carrier. J-A, which contains A-6% by weight sodium carbonate, is used as a carrier.

Along with the extreme periphery arrangement of palladium in the catalyst grain, it is necessary that the proposed catalyst, in addition, be modified with mercury or mercury and sodium sulfide in order to achieve a selectivity consistent with the prior art. In addition, the sensitivity to harmful substances increases due to the inevitable partial poisoning by mercury and sodium sulfide and, as a result, the service life of the catalyst is reduced. Regeneration, especially in situ, is associated with difficulties, since under normal regeneration conditions, added modifiers are partially removed from the catalyst. Due to the extremely high concentration of palladium on the geometric surface of the carrier, a loss of noble metal inevitably occurs.

The aim of the invention is to increase the productivity of the catalyst.

The use of the proposed catalyst allows for pain

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There is a great yield of cyclohexanone, as well as a high degree of phenol conversion. The catalyst has a longer service life, the activity and selectivity of which could be easily and purposefully adjusted within the framework of the method, the catalyst has a low bulk density and ensures the efficient use of palladium.

The basis of the proposed method is a method of selectively hydrogenating phenol to cyclohexanone in the gas phase using an active palladium catalyst on a carrier with high intrinsic selectivity, providing in all working phases both the degree of phenol conversion and the high yield of cyclohexanone and long service life are high. catalyst.

Although microporous catalysts with a highly developed surface or with a high content and high dispersion of palladium have high activity, their selectivity to the resulting cyclohexanol, as well as the formation of other, undesirable condensation products, is relatively small. The main reason should be sought in the continuation of the hydrogenation of cyclohexa- sanone inside the catalyst granule, caused by the slow mass transfer. Such high activity must be reduced in order to improve the selectivity by partial, irreversible poisoning.

Microporous catalysts with an underdeveloped surface have a relatively low activity compared to the previous ones, despite the rather high concentration of palladium. In both cases, the service life of the catalysts and the flexibility of the hydrogenation process are limited by the actual activity.

The next task is to create a catalyst for the process, which has a high selectivity of hydrogenation without complex and, as a rule, irreversible deactivation due to the optimum concentration and distribution of palladium in the carrier molding at a constant large primary activity and not inhibiting mass transfer.

A high concentration of alkaline earth metal oxide or hydroxides in an alumina carrier has a positive effect on certain catalytic properties, however

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This is due to the fact that an optimal porostructure is not formed, the catalyst has a large bulk density, the formation of alkaline earth oxide carriers during impregnation with active components is prone to cracking or destruction, and the reverse production of palladium from spent catalysts is possible with great difficulty and only with large losses x At the same time, it is necessary to change the concentration of calcium or alkaline earth megaballs without reducing the positive effect of these components on the activity and selectivity of catalysts. lysator.

The process conditions influence the selectivity, the runtime of the catalyst, as well as the flexibility and stability of the hydrogenation process, for example, J with variations in the parameters of the mode or composition of the feedstock. In this case, it is impossible only by controlling the hydrogenation process using the temperature in the reactor or the amount of hydrogen b to constantly exist throughout the operation of the high conversion of phenol and at the same time a large yield of cyclohexanone and the maximum service life of the catalyst. This is also impossible because the various influences that affect the load — the changes in the composition of the initial products, the changes associated with the aging of the properties of the catalysis: —Tori depending on the service life, require different temperature changes; for the process.

In many cases, the service life of the catalyst or the conversion of phenol is significantly impaired due to the small amount of poorly removed impurities specific to the initial product. . In this case, it is necessary to eliminate the undesirable influence on the process of hydrogenation of specific impurities for the initial product and to create additional possibilities for controlling the temperature in the reactor, the conversion of phenol, and the yield of cyclohexanone.

This is achieved by the method of selectively hydrogenating phenol in the gas phase at 100–200 ° C in the presence of a palladium catalyst on the carrier, and according to the proposed method, the content of palladium in the catalyst is 0.1–1.0 wt.% Deposited on the peripheral surface. odds

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carrier, with alumina modified with calcium as the carrier, the content of: calcium at (0.5–4 wt.%) is calculated as calcium oxide, and the calcium component is in a physico-chemical state in the catalyst that does not allow It is possible to determine a significant amount of calcium aluminate using conventional radiographic methods. The catalyst has a bulk density of 0.6 kg / l, a specific surface area of 120-170 and a total pore volume of at least 0.5 cm / g, of which at least 30% with a radius of

ABOUT

 500 A, and the gaseous initial mixture contains a moderator or a co-. The reaction formed in situ under the reaction conditions, and. The temperature of the gaseous feed mixture entering the catalyst bed is above the thermodynamic saturation temperature of the phenol.

A moderator or suitable compound is present in the feed and / or added to the gaseous mixture before entering the reactor.

When carrying out the process according to the proposed method, hydrogen-containing hydrogenation gas is used with a density of 0.3-1.0 kg / m in normal condition.

The necessary apparatus for carrying out the proposed process consists of a phenol evaporator, a heat exchanger, a reactor and a series-connected apparatus for separating the reaction products. The hydrogenation gas is vaporized in the evaporator with phenolic vapor and heated in a heat exchanger to the desired temperature at the inlet to the reactor. Selective hydrogenation occurs in a tubular reactor filled with catalyst and cooled with a jacket. After exiting the actor, there is a separation from the gaseous reaction mixture using condensation of cyclohexanone, an insignificant amount of cyclohexanol and unreacted phenol. The remaining gas, which is largely free of the reaction products, can be fully or partially returned to the evaporator after adding the required amount of fresh gas i hydrogenation.

According to the proposed method I, the process is carried out mainly with a catalyst containing 0.3-0.7

wt.% palladium and 1.5-3.0 wt.% calcium oxide, and the indicated amounts of calcium (calcium oxide) serve as the basis for calculations and do not indicate the physicochemical nature of the calcium components in the catalyst. Due to the physicochemical state of calcium in the catalyst, despite the decrease in calcium oxide concentration, unexpected partial improvements in catalytic properties are achieved by one order compared with catalysts containing 10–50 wt.% Calcium or other alkaline earth metal oxide. The compressive strength of the molding is good and its abrasion under mechanical load is very small.

Palladium is deposited predominantly on the surface of the carrier in the form of a peripheral surface up to 1 mm thick. Extreme peripheral distribution, for example, a penetration depth of 50.2 mm, does not lead to an improvement in selectivity, but inevitably greatly increases palladium loss due to abrasion when the catalyst is technical.

Preferably, the specific surface area of the catalyst is 135-150 cm, the pore volume is not less than 0.65 cm / g,

ABOUT

make up 60% of pores with a radius of 100 A; 10-15% of pores with a radius of 100-500 A and at least 30% of micropores with a radius of more than 500 A.

Due to the proportional ratio of macro- and micropores, as well as the concentration contained in the catalyst, corresponding to the pore structure, specific surface area and distribution of palladium, high catalytic activity is achieved, and excellent selectivity of the catalyst is achieved without activation or partial poisoning. mainly partial poisoning, and occurs without obstruction.

The preferred form of the catalyst is extrudates with a diameter of 2-6 mm and

8-15 mm long.

The physical and chemical properties of catalysts, in particular, its composition, its physical and geometrical structure, and the chemical state of its components determine its high catalytic activity, excellent

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20 25

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50

55

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Selective qualities, as well as very good activity — time during the selective hydration of phenol. Partial poisoning, for example, in hydrazine treatment with sulfur or mercury compounds does not occur, so there is no need for a reduction reaction outside the reactor, which requires a lot of money.

Cyclohexanone yield and catalyst life increase due to the use of a retarder, used as an additional means of controlling the process. The moderator used is predominantly carbon monoxide, which is formed in situ in the catalyst from formic acid. The formic acid, which is contained in small amounts in phenol, when receiving the phenol by the cumene method, the removal of which presents a considerable difficulty, undergoes dehydration on the catalyst according to the invention under the selected process conditions, predominantly to form carbon monoxide. The formic acid is contained as an admixture in the phenol used. It can also be added to the phenol in the form of an aqueous, alcoholic or phenolic solution or to the original gaseous mixture at some other place in front of the reactor. The preferred formic acid concentration, based on the amount of phenol, is 2-50 ppm.

The concentration of carbon monoxide in the reactor is set depending on the mode: the amount of formic acid, how much it is not specified by the content in the starting product, the amount of gas returned in the process after a very significant separation of the reaction products and / or complete or partial methanization of carbon monoxide. vrat gas. Methanization occurs on a nickel catalyst at temperatures between 140 and 250 ° C, preferably in a side stream, which allows the use of phenols with a concentration of formic acid of more than 50 ppm.

In addition to carbon monoxide, other moderators can be used, for example water or ammonia. In this case, the concentration of the retarder in the reaction mixture is set so that, under possibly mild reaction conditions, both a high degree of phenol conversion and a high yield of cyclohexanone are achieved. It also depends on the appropriate level of catalyst activity. New or fresh catalysts after regeneration require a higher retarder content for an optimal mode than catalysts with a longer service life.

Good effect on increasing the yield of cyclohexanone and reducing the consumption of hydrogen is the use of a relatively high density of hydrogenation gas. The process is conducted predominantly with a gas density of 0.5-0.85 kg / m in the normal state.

It has been found that, despite the exotherm of the hydrogenation reaction and the undesirable effect of high temperatures

in the cyclohexanone formation reactor, the result of the hydrogenation process is improved if the temperature of the gaseous feed mixture at the entrance to the catalyst bed exceeds the normal reactor temperature or the thermodynamic temperature to saturate the phenol.

In the proposed method, in comparison with the known ones, a highly active and highly selective catalyst is used, the level of activity of which can be quickly and reversibly adapted to each production situation, primarily using the retarder concentration. Thus

Therefore, as a result of the maximum activity of new or fresh catalysts after regeneration, the result of work in the initial phase due to limited selectivity and after a long service life due to too limited activity does not decrease. In addition, the proposed method allows quickly and reliably eliminating technically unavoidable variations in the process parameters or product composition without deteriorating the conversion or selectivity, allows for consistently high yields of cyclohexanone while simultaneously producing a high degree of phenol conversion and a longer regeneration cycle. .

With this, the hydrogenation gas, due to the high density of the gas, can be optimally used in the process of chemical transformation dL - and the requirements for the purity of the phenol, especially

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in relation to the formic acid content, it is significantly lower, and the costs of purification during the synthesis of phenol are markedly reduced.

The proposed catalyst creates significant advantages. Its use is so simple that it eliminates the subsequent reduction reaction, associated with technological costs, or partial deactivation, which is necessary for all known, sufficiently active catalysts. Significant economic advantages are, in addition, low bulk density and a relatively low content of palladium. For example, for a catalyst according to DE-PS 69585 and 85341 with a bulk weight of about 1.0 kg / l per meter. the volume of catalyst with a palladium content of 0.6 wt.%, 6 kg of palladium are needed. In the proposed catalyst with a bulk weight of, for example, 0.58 kg / l, it has been established that with a palladium concentration of 0.5 wt.%, The same or better catalytic properties are achieved. This means that only 1.9 kg of palladium is needed per catalyst. This advantage is even more noticeable when compared with catalysts containing spinels, proposed in DE-PS 92243, with a palladium concentration of 1.8% by weight. In terms of one reactor charge, a considerable saving of the noble metal is obtained.

Research has shown that, compared with known catalysts rich in calcium or oxides of alkaline earths, the loss of palladium in the processing of used catalysts can be significantly reduced due to the reduced calcium content.

Example 1. By precipitating alkali sodium aluminate with an acid solution of aluminum nitrate, aluminum hydrogel of the boehmite type is obtained by a known method, mixed in a kneader into a plastic mass and molded into an extruder into extrudates with a diameter of 3.4 mm. Drying or calcination is carried out in a belt dryer and in a conveyor calcination furnace with a residence time of 150 or 360 minutes, at 0-110 or 480-500 ° C,

12 liters of an almost neutral solution of calcium nitrate prepared from calcium oxide and nitric acid with a calcium content of 78 g / l are diluted

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water according to the water capacity of the carrier is 83% up to a volume of 58 liters and sprayed onto 70 kg of the molded alumina article by spraying.

Vysuiny in a belt dryer at -10 - the carrier is modified by calcium and then rotates with the tube furnace.

In order to establish the required catalyst texture, annealing is performed at the inlet temperature, at the temperature of the calcination zone with the passage of the annealing product 2.7 of the inner surface.

Eight segments with three rotary plates every and about 4, ovens / min ensure uniform calcination of the carrier. The introduction of a countercurrent of combustible gases in the amount of 400 standards, gas / h ensures uniform heating of the molded catalyst blanks and the removal of the existing residual water vapor from alumina.

The carrier is obtained with the following

Characteristics: Total pore volume (Vp), Micropore volume (I), Mesopo volume (Vp 100-500 A), Macropore volume (i), Surface, m / g X-ray structure

low moisture, wt.% 78

-A1 u-A1,0,

0.73 0.38 0.09

0.26,139

L

3 kg of palladium nitrate solution containing 100% by weight of Pd is increased to 39 liters of total volume with 78% by weight of distilled water, mixed well and brought into contact with 50 kg of catalyst carrier for 35 minutes.

Then the wet catalyst is immediately exposed to the substance for 30 minutes with hot air at -Y C.

After 24 hours of drying, the annealing is carried out in a tunnel oven at 450- 470 ° C, and the palladium nitrate decomposes and is fixed on a peripheral firmly adherent, dispersed palladium layer 0.4 mm thick.

The catalyst is characterized by the following indicators, wt.%: Pd content 0.57; CaO 1.8 content; native weight 0.54; strength isti 55618

to

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12

early 99.5; abrasion 0.4; penetration depth of the layer is 0.4 mm.

X-ray structure, texture, surface and pore volume correspond to the support.

Determination of mechanical strength is carried out by a standard method using a twist drum with four transverse ribs at 60 rpm for 15 minutes.

Example 2. The characteristics used in this example, the catalysts are given in table.1.

Table 1

peripheral layer of Pd, mm X-ray structure y-AlOj, Little

54 g of catalyst A or 60 g of catalyst B are placed in a reaction tube, around which a heating or cooling medium flows and treated with hydrogen for 8 hours at. After establishing a temperature of 135 ° C in the reaction space, a mixture of 70 l / h of hydrogen containing 49 g of vaporous phenol is passed through the catalyst at normal pressure in one pass. The amount of carbon monoxide added to hydrogen is set such that the average CO content is 150 ppm. After separation of the condensable components, a reaction product is obtained, containing on average 97-98 wt.% Cyclohexanone, 1.5-2 wt.% Cyclohexanol, and also 0.5 wt.% Unreacted phenol. The share of high-boiling by-products is 0.1 wt.%.

In order to maintain, as far as possible, a constant and optimal composition of the hydrogenation product while reducing the degree of conversion of phenol, the concentration of carbon monoxide is reduced.

1312556

in hydrogen after 1400, 3200 and 5100 hours to 120, 90 and 70 ppm.

Tests are continued for 10,500 or 12,000 hours without observing a decrease in catalyst performance.

Example 3. In catalytic apparatus, for testing, respectively, 55 g of catalysts are used, whose characteristics are given in Table 2.10.

table 2

Specifications

Catalyst Indicators

With obe, e with.%

Pd

Cao

Bulk weight, kg / l

Surface ,, m / g

Total pore volume, cm Volume noph 500 A,

The depth of penetration of the peripheral layer, mm0,3

X-ray structure G-A1, Oz, little

 . After an activation phase in a stream of hydrogen at 185 ° C for 6 hours, a mixture of 70 l / h of hydrogen and 47 g of vaporous phenol containing 380 ppm of formic acid is passed at 135 ° C in the reaction space in one pass through the catalyst.

Analysis of the condensable components gives a reaction product containing on average 97.7-98.4 wt.% Cyclohexano, 152-1.6 wt.% Cyclohexanol, and also 0.3 wt.% Unreacted phenol. The share of high-boiling by-products is 0.07 wt.%.

When the degree of conversion of phenol is reduced after 1600, 4500 or 8100 hours, the concentration of formic acid in phenol is reduced to 300, 220 or 160 ppm, respectively, after which the pervonal pH of the product of the hydrogenation product is set or kept almost constant.

In general, testing continues for 11,500 hours of operation without observing a decrease in the performance of the catalyst.

Example 4.; (Comparative). For comparison, we offer 1 um test

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catalyst (98g) manufactured according to DD-85341 with the following characteristics:

Content, May.% Pd0,54

CaO23,7

 Bulk weight, kg / l 0.98 Surface, m / l 112 Total pore volume, cm / g 0.17 Pore volume

g 100-500 A, CMVr 0.09 Pore volume g 100 A, 0.1 Activation and catalytic testing are carried out similarly to Example I, To achieve the optimally possible amounts of cyclohexanone, the CO concentrations in the gas are used depending on the time of exotation, which are given in table.3.

Table 3 Time, h | 40o | 90o | 160o | 210o | 2800

CO concentration, ppm 190 140 90 60 40

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Time h

3500 3800

CO concentration, ppm

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After separation of the condensable components, a reaction product is obtained, containing on average 93 wt.% Cyclohexanone, 4-5 wt.% Cyclohexanol, 1.5 wt.% Of unconverted phenol and 0.6 wt.% Of high boiling impurities.

After 3800 hours, there is a marked decrease in the degree of conversion, which cannot be compensated for by a further decrease in the carbon monoxide content. The catalyst, in order to restore its working capacity, must be regenerated with a nitrogen-air mixture in situ at 185 C.

For comparison, the same fresh catalyst was tested without the addition of a retarder. The product of hydrogenation obtained in this case has, on average, 78 - cyclohexanone 16 cyclohexanol 5% of high boilers and 0.8% of low boilers.

Example 5. The method is carried out on a pilot plant hydrogenation

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with a catalyst volume of 30 liters in a hydrogenation gas circulation mode.

The phenol is evaporated by the gas in the cycle, the mixture is heated to the setpoint (methanization) in the partial flow of the circulating gas.

Table I shows the conditions and results of the test when the bob is operated.

at this temperature, the conversion occurs and the load increases in the tubular reactor from the evacuator, the density of the gas by the hydro- gen of the reaction heat. Next, lower the dosage of the moderator or d t the condensation of the reaction product and methane depending on the cost of separation from the gas of the formic acid source

After withdrawing from the cycle the quantity of product and the required gas concentration determined by the content of the inert moderator.

gases, a circulating pump using a catalyst, described equals the pressure loss of the apparatus. in the example.

After the addition of fresh gas and the heating-molar ratio of gas to phenox, a new filling of pheno-15 P-10: 1 occurs, the saturation temperature with pell, followed by reaction in a reactor, is below 130 ° C. Fresh gas contains re 95-97 vol.% Hydrogen, inert gases nitrogen, methane and argon with non-permanent

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Testing equipment allows

to establish certain Q concentrations of the moderator in the circulating gas. Higher readings are obtained when phenol is added with an increased content of formic acid ((500 ppm) in the starting product, in 25 catalyst bots up to 33120 h and even more, as the decrease in the content compared to limestone methods, the moderator occurs due to catalysts. which, the life of the lytic conversion catalyst, carbon monoxide, exceeds 27,000 hours.

; Table A

After 8300 hours of operation, the nitrogen – air mixture is regenerated by a known method at.

The use of the proposed catalyst allows to increase the lifetime

Characteristics

35 I 250 1400 I 3200 j 3240 6150 | 8300 30 1500

p o

before

status

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0.9 0.9 0.9 1.0 G, O I,

five

6363

6060

G20100

0,500,50

408

5t, 5

408

51

6365 6568

3970 4143

8050 5065

0,700,400,710,67

409

412

412

416

25.5

63.0. 26.5 29.0

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sixteen

yes (methane) in the partial flow of the circulating gas.

Table I shows the conditions and results of the test when the bob is operated.

catalyst bots up to 33120 h and more as compared to limestone methods, in which the lifetime of the catalyst does not exceed 27000 hours

After 8300 hours of operation, the nitrogen – air mixture is regenerated by a known method at.

The use of the proposed catalyst makes it possible to increase the term of performance with the number of hours

1.0

P

0.9 8

1.1 13

6365 6568

3970 4143

8050 5065

0,700,400,710,67

412

412

416

424

410

410

63.0. 26.5 29.0

2I.O

35.0

26.0

nnOTHocTfc, kg / n norms. status Sodwrh nne SO, PTTM

Ha lowered yes “years, m iorm. status, / h

Fresh g "er, n norms. coct./h

Retarder dosage, 10 m / h

Furs meyrovanny gas "standards, status / h

0.590.59 0.840.470.860.820, VG0.740, H4

13012510060608030120VO

1.30.90, 50.50.70.80.650.8 0.9

12,812,311,9Г4,213,514,313,112,414,6

0.5 0.2

0.8 1.8 4.4

1.4

Editor N. Gunko

Compiled by R. Margodyna

Tehred I.Popovich Proofreader .M. Demchik

4785/28

Circulation 379 Subscription

VNISHVD USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

0.8 1.8 4.4

1.4

Claims (1)

METHOD FOR PRODUCING CYCLOHEXANONE by hydrogenation of phenol in the gas phase at 100-200 ° С in the presence of a catalyst containing 0.1-1.0 wt.% Palladium on alumina as a carrier modified with calcium oxide, characterized in that, in order to increase the productivity of the catalyst, use a modified catalyst containing palladium in the peripheral layer, as well as 0.1-4 , 0 wt.% Calcium oxide, while the catalyst has a bulk density of 0.5-0.6 kg / l, a specific surface area of 120-170 m ^a / g, a total pore volume of 0.6-0.8 cm ^e / g moreover, pores with a radius of 100 A are 0.350.40 cm ³ / g, and with a radius of more than 500 A - - 0.2-0.3 cm ³ / g, the process is conducted in the presence of carbon monoxide obtained during the reaction or with the addition of formic acid. 1,125