Hydrogenation of some oxygen-containing compounds on deposited iron-copper catalysts

HYDROGENATION OF SOME OXYGEN-CONTAINING COMPOUNDS ON DEPOSITED IRON-COPPER CATALYSTS* B. P. VAINSHTEIN, L. KH. KAGAN, I . B . RAPOPORT,

V. YA. KRUGL/KOV

and V. D. KAPKIN The All-Union Scientific tlesea~ch Institute for Petroleum and Natm'al (tas Refining and the Production of Synthetic Liquid Fuel (Receiced 28 November 1961)

CATALYST based on nickel and cobalt m a y be used for the h y d r o g e n a t i o n o f esters, acids, aldehydes, and ketones. Most frequently, nickel and c o p p e r c h r o m i u m catalysts are used [1-3]. The possibility of using catalysts based on iron for the h y d r o g e n a t i o n of aldehydes was first established b y V. N. I p ~ t ' e v [4]. H y d r o g e n a t i o n was carried out at a t e m p e r a t u r e o f 350 ° and a pressure of 100 atm. A. N. B a s h k i r o v et al. [5] studied the h y d r o g e n a t i o n of earbonyl c o m p o u n d s to alcghols o v e r sintered iron catalysts and showed their complete suitability for this at a pressure o f 100-200 arm and a temp e r a t u r e of 200-250 ° . I n investigations on the synthesis of o x y g e n - c o n t a i n i n g c o m p o u n d s from carbon m o n o x i d e and h y d r o g e n over deposited i r o n - c o p p e r catalysts, it was established t h a t when an initial gas rich in h y d r o g e n is used the reaction p r o d u c t s contain an increased a m o u n t of alcohols. I t m a y be assumed t h a t a higher partial p:essure of h y d r o g e n favours the h y d r o g e n a t i o n of esters a n d earbony] e
100 em a o f the i r o n - c o p p e r catalyst, which had been reduced with h y d r o g e n at 415 ° for 6 hours, was charged into the reactor. T h e reaction zone was h e a t e d electrically. The t e m p e r a t u r e was m e a s u r e d with a t w o - p o i n t t h e r m o couple with an a c c u r a c y o f ~ 3 °. H y d r o g e n a t i o n was carried out in a continuous s y s t e m u n d e r a pressure o f 30 a r m at 100-250 ° a n d space velocities (reckoned on the liquid raw material) * Neftekhimiya 2, No. 1, 100-105, 1962. 76

Catalytic hydrogenation of some oxygen-containing compounds

77

/

from 0-03 h -1 to 0.70 h -1. The hydrogen was fed in an am ount of from 3000 to 10,000 volumes per volume of raw material. The plan of the hydrogenation apparatus is shown in Fig. 1. Hydrogen, fed from cylinder 1 through reducing valve 2, passed through a chamber for purification from sulphur 3 and through a differential manometer 4 into the reactor 7. On leaving the reaction zone, the hydrogen passed through

'2

To

atmosphere

!

t

Em~i'~gn

FIG. 1. Flow sheet for hydrogenation at a pressure of 30 arm: I - - cylinder; 2 - r e d u c i n g valve; 3--chamber for purification from sulphur; l--differential manometer; 5--dropping bottle; 6--valve; 7--reactor; 8--vessel for product; 9--millivoltmeter: / 0 - - w a t e r manometer; / / - - f l o w - m e t e r ; 12--gas meter; 13--check bottle.

the flow-meter 11, the gas meter 12, and the check bottle 13, and was discharged to the atmosphere. The raw material was fed to the reactor from the dropping bottle 5. To equalize the pressure, the upper part of the dropping bottle was connected with the hydrogen feed line to the reactor. The feed of raw material was controlled b y the valve 6. The reaction products were collected in the receiver 8 and flowed through a valve into a low-pressure receiver. Hydrogenation of esters. The but yl esters of C.~--C14 f a t t y acids, previously diluted with iso-octane in a 1 : 1 ratio, had the following characteristics: /t 20 D 1.4275; molecular weight 161; ester number 176 mg KOH/g. The hydrogenation was carried out at a space velocity of 0.1 h -l at a hydrogen : raw

78

B.P. VAINSHTEINet al.

material ratio o f 3000 (by volume) and at t e m p e r a t u r e s from 200 to 300 ° . As can be seen from the results given in Fig. 2, at 250-265 ° the degree o f conversion o f the esters was 87.4~o. W i t h a c o n t e n t o f 51-2~o o f esters in the initial raw material, the h y d r o genizate still contained 6.4% o f them, t o g e t h e r with 44.4% o f alcohols. mg KOH/g 220

!

3

'oo-.~ ~o

'80 "~ I8C .,Q ,',1

b~O e-.

ffi 0 ¢-

40 o e~

60

3O > g 20 ~. ©

2o

~o ~

0

FIG. 2. Degree of hydrogenation of a butyl ester as a flmction of the temperature at, a space velocity of 0.1 h 1: /--hydroxyl munber; 2--ester number: 3--degwee of conversion of the esters, °/o by weight. Increasing the t e m p e r a t u r e to 275 ° , a l t h o u g h it increased the conversion o f the esters to 93.8%, caused h y d r o g e n a t i o n to proceed partially to the h y d r o c a r b o n s , as the a p p e a r a n c e of w a t e r showed. E x p e r i m e n t s carried out to establish the d e p e n d e n c e of the d e p t h o f h y d r o g e n a t i o n on the space velocity of the raw material at 250 ° showed (Table 1) t h a t the o p t i m u m space velocity is 0 - 1 9 h -1, which corresponds to ~0.1 h -1, calculated as ester. The conversion of the esters a m o u n t e d to 85/o. o/ A f u r t h e r increase in the space velocity of the raw m a t e r i a l to 0.25 h -l (0.125 h -I as esters) led to a fall in the conversion o f the esters from 85 to 80~/o and, correspondingly, to a reduction in the c o n t e n t of alcohols in the h y d r o g e n i z a t e from 43 to 4l°/0 . H y d r o g e n a t i o n o f c o m p o u n d s w i t h a carbonyl group. The raw materials used were b u t y r a l d e h y d e , with the characteristics: n~° ]-3839; d~° 0.820; c a r b o n y l n u m b e r 745 mg K O H / g ; and m e t h y l e t h y l k e t o n e with the characteristics: n~° 1.3780, d~° 0-795; carbo~lyl n u m b e r 750 mg K O H / g . On h y d r o -

Catalytic hydrogenation of some oxygen-containing compotmds

79

TABLE 1. ])EGREEOF HYI)ROGENATION (IN °/o) OF TIlE BUTYL ESTERS OF C 7 -C14 ACII)S I)ILUTED WITH ISO-OCTANE IN A 1:1 RATIO AS A FUNCTION OF TIlE SPACE YELOCITY OF TIlE RAW MATERIAL (Pressure 30 a r m , t e m p e r a t u r e 250 °, r a w m a t e r i a l : hydro
Materials

Esters

I i Alcohols

Water of reaction

J

Degree o f conversion o f t h e esters

51.2

Raw material Product after hydrogenation

5.2 5.9 6.2 7.7 10.1 17.1

0"03 0.07 0.12 0'19 0.25 0"70

34'6 40"4 44"4 43"3 41"0 34"0

2.2 1-1

89.9 88.5 87 "9 85.0 80.2 66"5

genating butyraldehyde with a space velocity of 0.1 h -1 at a volume ratio of hydrogen to raw material of 3000, the conversion at 200 ° and 30 arm was 87.0% (Table 2). m~KOH]g 75G

100

700

oo 3

b

\

\ /

e~

// -,

\.

0 200

1;00

10 i

I

i

150

175

200

I

225 °C

FIG. 3. Degree o f h y d r o g e n a t i o n o f m e t h y l e t h y l k e t o n e as a ftatlction o f t h e t e m p e r a t u r e a t a s p a c e v e l o c i t y o f 0.1 h - l : 1 - - h y d r o x y l n u m b e r ; 2 - - c a r b o n y l n u m b e r ; 3 - - d e g r e e o f c o n v e r s i o n o f t h e m e t h y l e t h y l k e t o n e , o() b y weight.

When methyl ethyl ketone was hydrogenated under the same conditions (Fig. 3), the conversion was 77-1°/o. Increasing the temperature to 255 ¢~, although it increased the conversion of the methyl ethyl ketone to 85-4~o, ]ed to the formation of hydrocarbons. The dependence of the conversion

80

B.P.

V A I N S H T E I N et al.

T A B L E 2. D E G R E E OF IIYDROGENATION (1N ~ )

OF B U T Y R A L D E I I Y D E AS A FUNCTION OF TItE

TEMPERATURE

(Pressure 30 at.m, space velocity of the raw material 0.1 h -x, raw material: hydrogen ratio = I : 3000) Material

Butyrahtehyde Pro
Temperature, Aldehy(te ~C !

100 150 200

96-0 45.6 22.8 12.6

] Degree of Alcohols i conversion ' of the aldehyde 50'3 73.2 83.4

-52.5 76-3 87.0

of b u t y r a l d e h y d e , m e t h y l e t h y l ketone, a n d m i x t u r e s o f the b u t y l esters of the C~--Cla carboxylic acids on the h y d r o g e n a t i o n t e m p e r a t u r e show t h a t t h e r a t e s of h y d r o g e n a t i o n are in the sequence: a l d e h y d e > k e t o n e > esters. Hydrogenation of earboxylie acids. T h e i r o n - c o p p e r c a t a l y s t was used to h y d r o g e n a t e C 7 C 9 carboxylic acids with the following characteristics: molecular weight 120; acid n u m b e r 460 m g of K O H / g . T h e degree of h y d r o g e n a t i o n of the C~7 - - C~'9 acids, diluted with iso-octane in a 1 : 1 ratio, a t 250 °, 30 a t m , a n d a space v e l o c i t y of raw m a t e r i a l of 0.1 h ~ was 95-6°/o . U n d e r these conditions, t h e fact, n o t p r e v i o u s l y recorded, was o b s e r v e d t h a t esterification o f the acid b y the alcohol t o o k place w i t h t h e f o r m a t i o n of a b o u t 16°/o of esters. I n h y d r o g e n a t i n g t h e b u t y l esters of t h e C~--C14 acids, the a c t i v i t y of the c a t a l y s t did n o t change during two m o n t h s . T h e degree of h y d r o g e n a t i o n of t h e esters r e m a i n e d a t 85-88O/o . These results p e r m i t t e d us to pass to t h e s t u d y of t h e h y d r o g e n a t i o n of a m i x t u r e of o x y g e n c o m p o u n d s .

Hydrogenation of a mixture of oxygen compounds contained in the products CO and H 2. H y d r o g e n a t i o n was carried o u t o f a n oil o b t a i n e d

of synthesis from

b y synthesis o v e r a n i r o n - c o p p e r c a t a l y s t consisting o f ~70°/O o f o x y g e n c o m p o u n d s a n d ~ 3 0 % of h y d r o c a r b o n s , a n d also individual fractions boiling within t h e ranges: i . b . * - - 1 6 0 °, 160-320 °, a n d i . b . - - 4 5 0 °. T h e high-boiling fraction was o b t a i n e d b y v a c u u m distillation. T a b l e 3 gives the results on t h e c o n t e n t of f u n c t i o n a l g r o u p s before a n d a f t e r h y d r o g e n a t i o n in the 50-160 ° a n d 160-320 ° fractions. T h e acids a n d esters c o n t a i n e d in these fractions were a l m o s t c o m p l e t e l y h y d r o g e n a t e d ~o alcohols. T h e c o n t e n t of c a r b o n y l c o m p o u n d s fell to 0.3-0.6O/o . T h e c o n t e n t of alcohols in the f r a c t i o n u p to 160 ° increased f r o m 35 to 62~o , a n d in t h e 160-320 ° f r a c t i o n f r o m 30 to 60.5~o.

The hydrogenation of the oxygen compounds contained in the 50-450 ° fraclion was carried out a t 230 °, 30 a r m , a n d a ' s p a c e v e l o c i t y of t h e r a w m a t e r i a l * I.b. represents the initial bdiling point of the product --45-50:.

Catalytic hydrogenation of some oxygen-containing compounds

81

TABLI~J 3. COMI'OSITION OF T H E RAW MATERIAL AND T H E IIYI)ROGENATION PRODUCTS

(I~ % ~Y WEI(~HT) (Pressure 30 at,m, space velocity of raw material 0.1 h -x, temperature 230 °, raw material : hydrogen ratio 1 : 10,000) ' Composition of the oxygen -ompounds, o.{) by weight

Acids Esters Alcohols Carbonyl compounds Total oxygen compounds Hydrocarbons

Boiling point, °C

!!

Initial b.p.--160~ I 160-320° Raw Hydrogenation Raw Hydrogenation I material product material product 0.1 5.7 35-0 20.4 61.2 38.8

0.0 0.0 62.0 0.3 62.3 37.7

0.3 20.1 30-0 12.8 63.2 36-8

0 0 60.5 0.60 61.1 38.9

T~,BLE 4. [{ESVLTS OF T I t E HYDROGEN=ATION OF OXYGEN-CONTAININ(~ SYNTHESIS PRODUCTS ( 5 0 - 4 5 0 ° FRACTION)

(Prossure 30 arm, temperature 230 °, space velocity of the raw material 0.1 h-L raw material : hydrogen ratio ~ 1 : 10,000) Composition of the raw material and the hydrogenation products, and the yield of alcohols, % by weight

Acids Esters Alcohols Carbonyl compounds Total oxygen compounds including acids, esters, and carbonyl compounds Hydrocarbons Newly formed alcohols Yield of oxygen compounds in the hydrogenizate, calculated on the initial total of oxygen compounds Content of alcohols in the oxygen compounds of the raw material and the hydrogenizate Content of alcohols in the hydrogenizate, calculated on the total oxygen compounds in the raw material

aM/

material

1 "73 19"90 32"90 13"17 67"70 34"8 32"30

0"07 1"58

63'00 0"7 65'35 2"35 34'65

96.00 92.00 94-80 93-3 6-9 86.4

96"5

48'7

o f 0.1 h -1, w i t h v a r i o u s r a t i o s o f h y d r o g e n 15,000 v o l u m e s p e r v o l u m e o f r a w m a t e r i a l o f t h e f r a c t i o n b o i l i n g u p t o 450 ° ( T a b l e 4), f r o m 19.9 t o 1-58% , i.e. b y 92~o , a n d t h a t o f (; PcIro|t!lllll l

Hydrogenizate

Conversion of the oxygen compounds (other than the alcohols)

96"8

93.00 t o r a w m a t e r i a l (from 3000 t o per hour). After h y d r o g e n a t i o n the c o n t e n t of esters h a d fallen c a r b o n y l c o m p o u n d s f r o m 13.17

82

B. 1). VAINSHTEIN et al.

to 0.7%, i.e. b y 94.8%, while the content of alcohols had risen from 32.9 to 63-00/0. The degree of conversion of the sum of the oxygen compounds other than alcohols amounted to 93.3%, which included 86.4% of alcohols and 6.9% of hydrocarbons; the content of alcohols in the oxygen compounds rose from 48-7 to 96.80/0 . The consumption of hydrogen, calculated from the hydrogenation of the esters and carbonyl compounds amounted to about 0.7°/0 b y weight, calculated on the oil. The life of the catalyst in hydrogenation was about two months without any loss of activity. Thus, it has been shown that hydrogenation of the oxygen compounds (esters and carbonyl compounds) obtained in the synthesis of alcohols may be carried out at 30 arm and 230 ° over the catalyst for the synthesis of oxygencontaining compounds. Calculations have shown that the productivity with respect to liquid products of unit reaction volume in hydrogenation is 6-10 times higher than the productivity of unit reaction volume in the synthesis of these products. Consequently, for the hydrogenation of oxygen compounds present in the products of synthesis over an iron-copper catalyst, it will apparently be sufficient to set up one additional reactor for every 6-10 reactors for the synthesis of oxygen compounds. SUMMARY

1. The deposited iron-copper catalysts developed in V N I I NP, ~vhich are used for the synthesis of oxygen compounds, are suitable for the hydrogenation of esters, aldehydes, and ketones to alcohols at a pressure of 30 atm and temperatures of 200-250 ° . 2. It has been shown that over these catalysts: (a) the rate of hydrogenation of aldehydes and ke tones is considerably higher than the rate of hydrogenation of esters; and(b) when acids are hydrogenated, the partial formation. of esters b y the interaction of the alcohols formed and the acids is observed. 3. The possibility in principle of hydrogenating over iron-copper catalysts synthesis products boiling over various temperature ranges with contents of oxygen compounds of 70-80% has been shown. Tral~slated by B . J. H.¢ZZAI~D

REFERENCES 1. H. ADKINS and R. CONNOR, J . Amer. Chem. Soc. 53, 1091, 1931; H. A D K I N S and K. F O L K E R S , J . A m e r . Chem. Soc. 53, 1095, 1931 2. D. M. MAIOROV and D. V. MUSHENKO, K h i m . i tekh. t o p l i v i masel 3, 24, 1958 3. V. I. K A R Z H E V , B. Ya. R A B I N O V I C H and G. D. YEVSEYEV, K h i m . i tekh. topliv i masel 6, No. I. 15, 1961 4. V. N. I P A T ' E V , Zh. russk, fiz-khim, obshch. 39, 681, 1907 5. A. N. B A S H K I R O V , S. M. LOKTEV, Yu. B. K A G A N and G.V. SABIROVA, T r u d y inst. nefti Akad. N a u k S S S R , K I I I , 180, 1959