Kieselguhr

1466

Ind. Eng. Chem. Res. 2005, 44, 1466-1473

Effect of Catalyst Constituents on (Ni, Mo, and Cu)/ Kieselguhr-Catalyzed Sucrose Hydrogenolysis Utkarsh Saxena, Nivedita Dwivedi, and Sheelendra R. Vidyarthi* Department of Chemical Engineering, H.B. Technological Institute, Kanpur 208002, India

The multicomponent (Ni, Mo, and Cu) catalyst supported on kieselguhr was found to have a high activity for the hydrogenolysis of sucrose to produce industrially important glycerol, ethylene glycol, propylene glycol, and sorbitol. The catalyst was characterized by scanning electron microscopy, X-ray diffraction, and surface area measurement. The presence of Ni is very common in most of the catalysts used for this process. The presence of Mo and Cu promotes the activity of Ni when supported on kieselguhr. The concentrations of Ni, Mo, and Cu in the catalyst have been optimized to yield maximum glycerol during sucrose hydrogenolysis. 1. Introduction Glycerol, glycols, and other polyols have vast industrial usage, viz., in the manufacture of perfumes, beer, pharmaceuticals, ink, etc. The production of these polyols by petroleum or petroleum-based products is in practice. An alternative source of these polyols is the hydrogenolysis of agro-based saccharides such as sucrose. Hydrogenolysis of sugars was first performed by Zartman and Adkiens1 in 1933 in the presence of a copper chromium oxide catalyst by reducing it at 300 atm of pressureand 250°C. In successive years, many workers2-23 used different catalysts for hydrogenolysis of agro-based saccharides; comparatively, few investigations on sucrose hydrogenolysis were performed. A review of these works suggests that Ni with some additives supported on kieselguhr is an effective catalyst for sucrose hydrogenolysis. Srivastava2 has reported good yields of glycerol, ethylene glycol, propylene glycol, and sorbitol by the hydrogenolysis of sucrose in the presence of a (Ni, W, and Cu)/kieselguhr catalyst. The catalyst can be made cheaper if W is replaced by Mo. An almost similar performance is anticipated because both W and Mo are in the same periodic group. A (Ni, Mo, and Cu)/ kieselguhr catalyst has not been used before for sucrose hydrogenolysis. The catalyst composition has been optimized by carrying out hydrogenolysis reaction with various catalyst samples with varying concentrations of Ni, Mo, and Cu. The concentrations that yield maximum glycerol, the most expensive product, have been selected as the optimum for the catalyst synthesis. 2. Experimental Section 2.1. Apparatus and Procedure. (i) Catalysis Synthesis and Reduction. The catalyst was synthesized using a Heidolph rotary evaporator with automatic speed and temperature control. The unit consists of a rotating flask, a condenser assembly with a motor, and a trap assembly with a vacuum pump and a Bu¨chner funnel fitted in a filter flask. The catalyst was ground to pass through a 250-mesh screen before being reduced for the reaction. * To whom correspondence should be addressed. E-mail: [email protected].

The catalyst was reduced in a catalyst reduction unit that consists of a 47-cm-long stainless steel reactor tube of 2.5-cm diameter fixed in a 6-cm-diameter ceramic tube, which is bounded by a nicrome wire for heating. Hydrogen is passed through the tube at a known flow rate, set using a rotameter, after maintaining the desired temperature by adjusting the set points of the electronic controllers. The catalyst was prepared by addition of kieselguhr with a solution of nickel nitrate and cupric nitrate in water to form a slurry. A solution of molybdic acid and concentrated ammonium hydroxide was then added over a period of 30 min, and the resulting mixture was digested for 60 min at 80 °C. The slurry was finally digested for 90 min at 90 °C after addition of an aqueous solution of sodium carbonate dropwise for 30 min at 80 °C. It was then filtered and washed with hot distilled water and dried under vacuum at 150 ° C. The dried catalyst was then passed through a 200-mesh sieve. The catalyst was activated by reduction in a pure hydrogen current at 600 °C for 2 h. A higher reduction temperature than the typical 450 °C or less for various Ni catalysts is needed to reduce the oxides of Mo. The catalyst reduced at this temperature gave higher glycerol yields than the catalyst reduced at other temperatures. (ii) Catalyst Characterization. The optimized catalyst was characterized using the techniques of X-ray diffraction, electron microscopy, and surface area measurement. Finely powdered samples of pure kieselguhr and (Ni, Mo, and Cu)/kieselguhr (unactivated, activated, and spent catalysts) were mounted using a Seifert MZ III goniometer and were examined using a Seifert X-ray generator (model JSO Debye Flex 2002; Ennepatel, Germany). The X-ray data were recorded at a scanning speed of 1.2°/min between θ ) 10° and 90°. The monochromic beam of Cu KR radiation was used. The diffractometer was operated at a count rate of 5K cpm and a time constant of 10 s. The scanning slit was fixed at 2 mm and the receiving slit at 0.3 mm. The X-ray tube was driven at 30 kV and 20 mA. The diffracted intensities were measured by a scintillating column at a sweep rate of 3.0/min. Various catalyst samples and the kieselguhr were examined under a JEOL JSM-8408 (Peabody, MA) scanning electron microscope.

10.1021/ie049473v CCC: $30.25 © 2005 American Chemical Society Published on Web 02/02/2005

Ind. Eng. Chem. Res., Vol. 44, No. 5, 2005 1467

Figure 3. Scanning electron micrograph of an unreduced (Ni, Mo, and Cu)/kieselguhr catalyst. Figure 1. Scanning electron micrograph of kieselguhr particles (×5000).

Figure 4. Scanning electron micrograph of a reduced (Ni, Mo, and Cu)/kieselguhr catalyst. Figure 2. Scanning electron micrograph of kieselguhr particles (×3000).

Surface area measurements of the catalyst were carried out by a single-point Brunauer-Emmett-Teller method with the help of Quantachrome model OS 7 (Quantachrome Corp., Greenvale, NY), using a N2 adsorbent. (iii) Hydrogenolysis Reaction. Hydrogenolysis reactions were carried out using a 450-mL Parr series 4560 minibench top reactor supplied by Parr Instrument Co. (Moline, IL). The reduced catalyst was quickly transferred into the stirred reactor vessel containing an aqueous solution of sucrose. The reactor was immediately closed and was evacuated by connecting a vacuum line to an opening valve. These operations were performed in the least possible time to minimize oxidation of the catalyst. The reaction vessel was placed in the reactor assembly, and heating was switched on. When the desired temperature was reached, the hydrogen pressure was brought to the required level, and this was taken as the starting time for the reaction. Samples were taken out at fixed intervals using a sampling tube attached to the reactor. The reaction was kinetically controlled at the selected stirring speed of 600 rpm. (iv) Product Analysis. The method of thin-layer chromatography coupled with flame ionization detection was used for the product analysis. The equipment used

Figure 5. Scanning electron micrograph of a reduced (Ni, Mo, and Cu)/kieselguhr catalyst.

was an Iatroscan TH-10 MK-IV TLC/FID analyzer. Silica gel chromarods were used as adsorbent columns, and the reaction products were separated on them using different solvent systems for different products as

1468

Ind. Eng. Chem. Res., Vol. 44, No. 5, 2005

Figure 6. X-ray diffraction chart of a reduced (Ni, Mo, and Cu)/kieselguhr catalyst.

Figure 7. X-ray diffraction chart of a spent (Ni, Mo, and Cu)/kieselguhr catalyst.

described below. Analysis of polyols as well as of saccharides using the same stationary phase (silica rods) with different solvent systems made the method attractive for use in the study. Spotted dried and developed glycerol ethylene glycol and propylene glycol saccharides and sorbitol

CHCl3/ MeOH/ HCOOH CHCl3/ MeOH/ H2O

80:20:0.5 90:12:1.4

CHCl3/ MeOH

60:40

silica gel rods with their holder were placed in the analyzer, which consisted of a flame ionization detector with a burner and a collecting electrode along with a movable assembly locating rods angled at 30° to the axis of the flame. The signals obtained from the electrode were processed in an Iatrocorder TC-II attached with a TLC/FID analyzer. The recorder plots a chromatogram, along with an actual baseline used, in real time and from memory. The chromatograms were used to evaluate the product yields. By analysis of standard samples of known composition, an estimation accuracy of 2% was observed. The standard deviation was 1.3%. 2.2. Chemicals. (i) For synthesis: laboratory grades of nickel nitrate (Qualigens, Mumbai, India), copper

nitrate (Qualigens), molybdic acid (Judex, England), liquor ammonia (Qualigens), and sodium carbonate (Qualigens). (ii) Support: kieselguhr (S.D. Fine Chemicals, Bangalore, India). (iii) For analysis of the products: analytical grades of chloroform (Ranbaxy, New Delhi, India), methanol (Qualigens), HCl (Qualigens), glycerol (Qualigens), ethylene glycol (Qualigens), propylene glycol (Qualigens), sorbitol (CDH), fructose (S. D. Fine Chemicals), and glucose (S. D. Fine Chemicals). (iv) For chemical analysis of the catalyst: analytical grades of nitric acid (Qualigens), acetic acid (Qualigens), lead acetate (Ranbaxy), ammonium acetate (Riedelf), ammonium nitrate (Ranbaxy), liquor ammonia solution (Qualigens), sodium sulfite (Ranbaxy), ammonium thiocyanate (Qualigens), absolute alcohol (Hayman Ltd., Essex, England), dimethylglyoxime (Ranbaxy), and tartaric acid (Qualigens). (v) For hydrogenolysis: laboratory grade of sucrose (Qualigens).

Ind. Eng. Chem. Res., Vol. 44, No. 5, 2005 1469 Table 1. X-ray Diffraction Pattern of Kieselguhr (Cu Kr Radiation Monochromatic Beam λ ) 1.542 Å) peak no.

d, Å

intensity, %

peak no.

d, Å

intensity, %

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

4.049 214 3.313 829 3.138 672 2.981 608 2.947 270 2.839 998 2.621 219 2.478 055 2.222 502 2.113 382 2.023 899 1.930 319 1.869 311 1.688 550 1.609 405

99.76 23.99 30.05 20.80 20.84 28.75 14.56 43.96 11.14 15.92 15.66 17.83 18.08 13.80 20.61

16 17 18 19 20 21 22 23 24 25 26 27 28 29

1.557 512 1.532 402 1.531 230 1.525 400 1.490 386 1.427 735 1.421 813 1.365 713 1.343 046 1.275 070 1.223 966 1.217 287 1.205 508 1.180 399

11.52 13.52 13.83 13.62 15.75 17.51 17.07 13.96 13.38 11.61 11.36 12.16 11.04 14.08

Table 2. List of d Values of Ni in X-ray Diffraction Charts of Reduced and Spent (Ni, Mo, and Cu)/ Kieselguhr Catalysts d values hkl

reduced catalyst

spent catalyst

111 200 220

2.057 560 1.783 595 1.260 194

2.039 460 1.771 115 1.246 927

2.3. Catalyst Characterization. Scanning electron micrographs of different portions of the kieselguhr sample at different magnifications are shown in Figures 1 and 2. The kieselguhr is seen to be a spongy material

with particles of around 1-µΜ size (Figure 1). Some dishtype particles of size 30 µM appear when the salts of Ni, Mo, and Cu are coprecipitated on the kieselguhr (Figure 3). Figures 4 and 5 are scanning electron micrographs of the reduced catalyst at various magnifications. It is seen that honeycomb- and dish-type structures of the unreduced catalyst disappear during the catalyst reduction and the entire material takes a spongy shape of almost uniform structure with Ni particles coated evenly over the kieselguhr surface. A comparison of the scanning electron micrographs of fresh kieselguhr (Figure 1) and of the reduced catalyst (Figure 5) reveals that the kieselguhr particles, after catalyst synthesis and reduction, get reduced to less than one-third of those in raw kieselguhr. This contributes to the catalyst surface area being much larger than the surface area of the raw kieselguhr. Although kieselguhr has been extensively used as a support for many catalysts, its X-ray data are rarely available in the literature. It mostly contains various forms of silica and some other materials in traces. The exact composition of the kieselguhr is not definite and depends on the source. Table 1 gives dhkl values and their relative intensities for kieselguhr used in this study. Figures 6 and 7 show X-ray diffraction charts of reduced and spent catalysts. Table 2 gives peaks of Ni identified in the reduced and spent catalysts. Ni peak intensities in the spent catalyst are seen to be lower than those in the reduced catalyst (Figures 6 and 7), indicating considerable deactivation of the

Table 3. Effect of the Ni Percentage in a (Ni, Mo, and Cu)/Kieselguhr Catalyst on Product Distribution catalyst sucrose concn temperature pressure Cu Mo

(Ni, Mo, and Cu)/kieselguhr, 12.5% by weight of sucrose 17% by weight 150 °C 50 atm 1.35% by weight of catalyst 7.60% by weight of catalyst % yield

run no.

% Ni in the catalyst

time, min

1

15.62

2

19.94

3

22.06

4

24.60

5

27.09

0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235

glycerol

ethylene glycol

propylene glycol

sorbitol

glucose

fructose

sucrose

0 1 3 5 6 5 0 3 9 15 22 22 0 5 12 19 25 25 0 9 16 22 25 24 0 14 21 24 24 22

0 2 5 10 14 13 0 3 8 14 20 19 0 4 9 16 22 21 0 4 10 17 23 22 0 3 10 18 23 21

0 0 2 3 3 3 0 2 5 9 12 12 0 2 6 10 14 14 0 2 6 10 14 13 0 2 6 10 12 10

0 2 4 6 7 6 0 2 4 5 5 5 0 2 4 5 4 4 0 2 3 4 3 3 0 1 2 3 3 3

0 6 9 9 5 5 0 6 11 12 8 6 0 6 12 13 9 6 0 6 12 13 9 6 0 6 12 12 7 6

0 5 8 9 8 8 0 4 8 9 6 4 0 4 8 9 5 3 0 5 10 10 6 4 0 7 12 11 8 7

100 81 66 49 45 44 100 77 52 31 19 18 100 75 46 25 14 13 100 71 40 22 14 13 100 67 35 20 16 15

1470


Figure 8. Effect of the Ni percentage in the catalyst on product distribution.

catalyst during the reaction. Deactivation of the catalyst is also experimentally observed and discussed elsewhere. Peaks of Mo and Cu could not be identified because at least 8% by weight of a substance should be present in its detection by X-ray diffraction. The surface area of the raw kieselguhr was 3.79 m2/ g. Perhaps the change in morphology of the kieselguhr during the process of coprecipitation and very small size of the Ni particles in the reduced catalyst contributed to the area of the finished catalyst being much larger than that of the raw kieselguhr. The reduced catalyst had a surface area of 692 m2/g. 3. Results and Discussion Sucrose hydrogenolysis is affected by the amount of Ni, Mo, and Cu in the catalyst. The concentrations of Ni, Mo, and Cu in the catalyst have been varied, and the effects of these variations on sucrose hydrogenolysis have been studied. The concentrations that give maximum glycerol yields have been selected as optimum for the catalyst synthesis. 3.1. Effect of the Catalyst Ni Loading. The percentage of Ni in the catalyst has been varied from 15.62% to 27.06% by weight. Table 3 gives the results of the hydrogenolysis reactions using catalyst samples with these variations. Figure 8 shows the variation of polyol and saccharide yields versus catalyst Ni loading.

Figure 9. Effect of the Mo percentage in the catalyst on product distribution.

The maximum glycerol yield is seen to be 25% by weight after 135 min of reaction time at a catalyst Ni loading of 22.06% by weight. The highest yield of total polyols is obtained at the same time period and the same Ni percentage. Therefore, this Ni loading can be taken as optimum for the catalyst. The unconverted sucrose amount is seen (Figure 8) to decrease rapidly initially with increasing the catalyst’s Ni amount. The decrease is less rapid beyond 20% Ni by weight, and the trend reverses when the Ni amount is 23% by weight. A perusal of Table 3 reveals that the change in the trend of the sucrose conversion with the catalyst’s Ni loading is apparent only after 55 min of reaction time; a faster deactivation of the catalyst during the reaction at higher Ni loadings is indicated by this. Conversion of the Ni from the metal state to its oxides may be the cause of the catalyst deactivation. The disappearance of the metallic Ni is also indicated by lowering of the Ni peaks in the X-ray diffraction pattern of the spent catalyst. Sucrose yields equal amounts of glucose and fructose upon being decomposed. However, Figure 8 shows that an increase in the catalyst’s Ni loading beyond 22.59% causes the unconverted amounts of sucrose and fructose to increase slightly and the unconverted amount of glucose to decrease a little bit. This indicates that the catalyst’s Ni loading beyond 22.59% favors glucose hydrogenolysis more than hydrogenolysis of sucrose and fructose. This

Ind. Eng. Chem. Res., Vol. 44, No. 5, 2005 1471 Table 4. Effect of the Mo Percentage in a (Ni, Mo, and Cu)/Kieselguhr Catalyst on Product Distribution catalyst sucrose concn temperature pressure Ni Cu


run no.

% Mo in the catalyst

time, min

6

3.04

7

4.87

8

7.10

9

9.22

10

10.91

0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235

glycerol

ethylene glycol

propylene glycol

sorbitol

glucose

fructose

sucrose

0 4 9 16 20 20 0 4 10 18 25 24 0 4 11 19 27 26 0 5 12 19 25 25 0 6 13 18 22 23

0 3 8 13 18 18 0 2 8 15 21 20 0 3 8 16 23 22 0 4 9 16 22 21 0 4 10 15 20 19

0 2 6 11 15 17 0 2 5 9 14 14 0 2 5 9 13 12 0 2 6 10 14 14 0 3 8 13 18 18

0 6 8 5 4 4 0 4 6 5 5 4 0 2 4 5 5 4 0 2 4 5 4 4 0 2 4 4 3 3

0 11 19 19 13 10 0 8 15 15 11 9 0 6 12 13 10 8 0 6 12 13 9 6 0 7 13 15 7 4

0 2 6 11 12 9 0 3 8 10 8 7 0 4 9 9 6 5 0 4 8 9 5 3 0 3 7 9 3 1

100 72 43 22 12 9 100 76 46 25 11 9 100 77 49 26 11 10 100 75 46 25 14 13 100 74 42 22 18 17

also shows that in this loading range glucose is hydrogenolyzed after its formation from sucrose rather than when it is one of the parts of sucrose because in the later case conversion of sucrose should also increase. 3.2. Effect of the Catalyst Mo Loading. Mo in the catalyst is varied from 3.04 to 10.91% by weight. The results of the hydrogenolysis reactions with these samples are given in Table 4. Figure 9 shows polyol and saccharide yields versus catalyst Mo loading at 135 min of reaction time. A value of 27% by weight is the highest glycerol yield when the Mo loading is 7.1% by weight; this value, therefore, is taken as optimum for the catalyst. Beyond 7.1% Mo loading, the decreasing glycerol yields are associated with the increasing propylene glycol yields. Glycerol is known to hydrogenolyze into propylene glycol;23 therefore, propylene glycol appears to be partially produced by glycerol hydrogenolysis in the present case as well. Figure 9 shows a decrease in the sucrose conversion when the Mo loading is increased beyond 7%. The increased Mo loading either may decrease the activity of the catalyst or may cause the catalyst to deactivate faster during the reaction. A perusal of Table 4 reveals that the change in sucrose conversion in this Mo loading range is much more noticeable only after a reaction time of 55 min. Therefore, faster deactivation of the catalyst during the reaction appears to be the probable source of decreased sucrose conversion. Probable causes of the catalyst deactivation have already been explained elsewhere.

3.3. Effect of the Catalyst Cu Loading. The catalyst’s Cu amount is varied from 0.312% to 1.65% by weight. The results of the sucrose hydrogenolysis using catalyst samples with these variations are given in Table 5. Figure 10 shows variation of polyols and saccharide yields versus catalyst Cu percentage. The maximum glycerol yield is 28.2% by weight at 1.10% Cu loading; therefore, this is taken as the optimum Cu loading for the catalyst. Beyond 1.10% Cu loading, the glycerol yield is found to decrease rapidly with a corresponding decrease in the sucrose conversion. The yields of other components, except propylene glycol, do not change appreciably. The propylene glycol yields follow the glycerol trend of rapid decrease. This indicates glycerol formation primarily through the sucrose hydrogenolysis rather than through the hydrogenolysis of glucose, fructose, or sorbitol formed during the reaction and propylene glycol formation primarily from the glycerol hydrogenolysis when the catalyst’s Cu loading is more than 1.10%. Glycerol hydrogenolysis is known to yield propylene glycol.23 3.4. Comparison of (Ni, Mo, and Cu)/Kieselguhr and (Ni, W, and Cu)/Kieselguhr Catalysts. The product yields with a (Ni, W, and Cu)/kieselguhr catalyst under similar operating conditions were reported by Srivastava.2 Table 6 gives the product yields with (Ni, Mo, and Cu)/kieselguhr and (Ni, W, and Cu)/ kieselguhr catalysts. The total yields of glycerol, ethylene glycol, and propylene glycol are almost the same for the two catalysts; however, the Mo-based catalyst

1472


Table 5. Effect of the Cu Percentage in a (Ni, Mo, and Cu)/Kieselguhr Catalyst on Product Distribution catalyst sucrose concn temperature pressure Ni Mo


run no.

% Cu in the catalyst

time, min

11

0.31

12

0.60

13

0.96

14

1.35

15

1.65

0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235 0 5 20 55 135 235

glycerol

ethylene glycol

propylene glycol

sorbitol

glucose

fructose

sucrose

0 2 8 14 19 21 0 3 12 19 25 24 0 4 12 20 28 26 0 4 11 19 27 26 0 3 9 16 19 19

0 3 8 13 17 18 0 2 7 14 20 21 0 2 7 14 22 22 0 3 8 16 23 22 0 4 11 18 22 20

0 1 3 5 7 7 0 2 4 7 10 10 0 2 5 9 13 12 0 2 5 9 13 12 0 2 5 7 9 9

0 1 2 4 6 6 0 1 2 4 5 4 0 1 3 4 4 3 0 2 4 5 5 4 0 2 4 6 8 8

0 1 4 8 11 9 0 5 9 10 9 8 0 7 13 12 9 7 0 6 12 13 10 8 0 3 8 11 11 11

0 1 3 6 8 10 0 3 7 8 7 7 0 4 10 10 6 5 0 4 9 9 6 5 0 2 6 9 9 9

100 90 70 45 27 25 100 83 57 34 18 16 100 79 48 28 12 10 100 77 49 26 11 10 100 80 54 32 18 18

Table 6. Product Yields with (Ni, Mo, and Cu)/Kieselguhr and (Ni, W, and Cu)/Kieselguhr Catalysts catalyst concn sucrose concn temperature pressure reaction time agitation

12.5% by weight of sucrose 17% by weight 150 °C 50 atm 135 min 750 rpm yield, wt %

product

(Ni, W, and Cu)/ kieselguhr

(Ni, Mo, and Cu)/ kieselguhr

glycerol ethylene glycol propylene glycol sorbitol glucose fructose sucrose unidentified products

30 14 20 9 10 6 4 7

28 22 13 4 9 6 12 6

appears to favor sucrose conversion to ethylene glycol over propylene glycol. Sorbitol decomposition with a (Ni, Mo, and Cu)/kieselguhr catalyst is higher, but its overall activity for sucrose hydrogenolysis appears to be a little less because more sucrose remains unconverted with this catalyst. 4. Conclusion (Ni, Mo, and Cu)/kieselguhr is an effective catalyst for hydrogenolysis of sucrose. The concentrations of Ni,

Mo, and Cu in the catalyst have been varied, and the effect of these variations on the sucrose hydrogenolysis has been observed. The concentration giving maximum glycerol yields has been taken as optimum for the catalyst synthesis. The optimum (Ni, Mo, and Cu)/ kieselguhr catalyst has the following composition: Ni, 22.06% by weight of catalyst; Mo, 7.10% by weight catalyst components; Cu, 1.10% by weight of catalyst. With this catalyst, after 135 min of reaction time, polyol yields by weight were 28% glycerol, 22% ethylene glycol, 13% propylene glycol, and 4% sorbitol, saccharide yields were 9% glucose and 6% fructose, unconverted sucrose was 12%, and there were 6% unidentified products. The catalyst loading was 12.5% by weight of sucrose, the sucrose concentration was 17% by weight, and the temperature and pressure were 150 °C and 50 atm. The catalyst has been characterized using techniques of X-ray diffraction, electron microscopy, and surface area measurements. Electron microscopy shows that the size of keiselguhr particles gets reduced during the catalyst preparation, thus increasing the surface area considerably. Ni peaks were visible in the X-ray diffraction charts. Ni peak intensities in the X-ray diffraction chart of the spent catalyst were lower than those of the reduced catalyst, indicating deactivation of the catalyst during the reaction. The peaks of Mo and Cu were not visible because their concentrations were lower than 8% in the catalyst. The surface area of the catalyst was 692 m2/g. (Ni, Mo, and Cu)/kieselguhr appears to be a promising

Ind. Eng. Chem. Res., Vol. 44, No. 5, 2005 1473

Figure 10. Effect of the Cu percentage in the catalyst on product distribution.

catalyst for sucrose hydrogenolysis. In comparison to the (Ni, W, and Cu)/kieselguhr catalyst, it is slightly less active for sucrose hydrogenolysis and favors sucrose conversion to ethylene glycol over propylene glycol. A process can be developed using this catalyst for polyol production through a sucrose hydrogenolysis route. Nomenclature θ ) angle in the X-ray diffraction chart Cu KR ) monochromatic KR radiation of copper X-rays cpm ) counts per minute dhkl ) interplanar spacing in a crystal λ ) wavelength of X-ray radiation hkl ) Miller indices

Literature Cited (1) Zartman, W. H.; Adkiens, H. Hydrogenolysis of Sugars. Am. Chem. Soc. 1933, 55, 45559-45563. (2) Srivastava, T. Studies on effect of various process variables and catalyst constituents on hydrogenolysis of sucrose. Ph.D. Thesis, Kanpur University, Kanpur, India, 1994. (3) Sakai, J. Hydrogenolysis of Carbohydrates. J. Chem. Soc. Jpn., Ind. Chem. Sect. 1949, 52 (Sept), 196. (4) Boelhouwer, C.; Korf, D.; Waterman, H. I. Catalytic Hydrogenation of Sugars. J. Appl. Chem. (London) 1960, 10, 292296.

(5) Invent a Akt. Ges. Fur Forschurgund Patent verwertung: Polygydric Alcohols from D-Glucitol (Sorbitol). British Patent 847,745, Sept 14, 1960; Chem. Abstr. 1960, 55, 7307g. (6) UDIC SA. Catalytic Hydrogenation of Reducible Sugar. British Patent 850,133, Sept 28, 1960; Chem. Abstr. 1960, 55, 20470c. (7) GoldSchmidt, H. R.; Perlin, A. S. Hydrogenolysis of Carbohydrate IX. Formation of 2,6-anhydro-β-D-fructofuranose and ethyl β-D-fructofuranoside from Sucrose. Can J. Chem. 1960, 38, 217886. (8) Vasyumina, N. A.; Balandin, A. A.; Slutskin, R. L. Hydrogenolysis of Mono Saccharides and Polyhydric Alcohols in the Presence of a System of Catalyst. Dokl. Akad. Nauk, SSR 1966, 169 (5), 1077-1079; Chem. Abstr. 1966, 66, 11143x. (9) Vasyumina, N. A.; Stutskin, R. L.; Balandin, A. A. Mechanism of Mono saccharides Hydrogenolysis and New Homogeneous Catalysis for this Process. Katal. Reakts. Zhidk. Faze, Tr. Vses., Konf., 2nd 1967, 511-514 (Russian); Chem. Abstr. 1967, 69, 10638c. (10) Kashagan, L. Hydrogenolysis of Reducible Sugars to Obtain a High Percentage of Glycerol. U.S. Patent 3,396,199, Aug 6, 1968; Chem. Abstr. 1968, 69, 78609z. (11) Vanling, G.; Driessen, A. J.; Piet, A.; Vlugter, J. C. Continuous Production of Glycerol by Catalytic High-Pressure Hydrogenolysis of Sucrose. Ind. Eng. Chem. Prod. Res. Dev. 1970, 9 (2), 210-212. (12) Rozdestvenskaya, I. D.; Fadeeva, T. N.; Titova, N. B. Some Features of Hydrogenolysis of Glucose. Kinet. Catal. 1970, 11, 568-73. (13) Wright, L. W. Tungsten Oxide Promoted Supported Ni Catalyst. U.S. Patent 3,691,100 (Cl. 252/458; Bo1 j), Sept 12, 1972; Appl. 9,059, Feb 5, 1970; Chem. Abstr. 1972, 78, 3676w. (14) Vishnevskii, N. E.; Losik, V. I.; Slutsbin, R. L.; Osypyan, L. A. Glycerol & glycol by Catalytic Hydrogenolysis of Sugars. USSR Patent 422,71 (Cl. Co7c), Apr 5, 1974; Appl. 1,738,998, Jan 16, 1972. Otkrytiya Izobret., Prom. Obraztsy, Tovarnye Znaki 1974, 51 (13), 90; Chem. Abstr. 1974, 81, 4209v. (15) Sabadie, J.; Barthomeuf, D.; Charcosset, H.; Descotes, G. Catalytic Hydrogenolysis of Oligosaccharides. (Lab. Chim. Org., ESCIL, 69622 Villeurbanne, Fr.) Bull. Soc. Chim. Fr. 1981 (7-8, Part 2), 288-292; Chem. Abstr. 1981, 96, 35664d. (16) Vidyarthi, S. R. Hydrogenolysis of sugars. Ph.D. Dissertation, IIT Kanpur, Kanpur, India, 1984. (17) Diacel Chemical Industries Ltd. Jpn., Kokkai, Tokyo Koho. Manufacture of polyols from Saccharides. JP 58,180,444 [83,180,444] (Cl. C07C31/18), Oct 21, 1983; Appl. 62/62,834, Apr 14, 1982; Chem. Abstr. 1983, 100, 212016t. (18) Zheug, B.; Lai, Z.; Yuming, L.; Shuren, J.; Cao, R.; Liu, R. (Nanning Polytech Developing Corp. for cassava utilization). Preparation of mannose and sorbose from sucrose. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 86,107,626 (Cl. C07C31/125), May 18, 1988; Appl. Nov 7, 1986; Chem. Abstr. 1988, 111, 114044h. (19) Schuster, L.; Himmele, W. (BASF AG). Preparation of Glycols and Polyols by Hydrogenolysis of Sucrose. Eur. Pat. Appl. EP 344,561, Dec 6, 1989; DE Appl. 3,818,198, May 28, 1988; Chem. Abstr. 1989, 113, 5696t. (20) Muller, P.; Rimmelin, P.; Hindermann, J. P.; Kieffer, R.; Kiennemann, A. Transformation of Sugar into Glycols on a 5% Ruthenium/Carbon Catalyst. (Lab. Chim. Org. Appl., Ehics, 67000 Strasbourg, Fr). Stud. Surf. Sci. Catal. 1991, 59 (Heterog. Catal. Fine Chem. 2), 237-244 (English); Chem. Abstr. 1991, 115, 183689s. (21) Casale, B.; Marini, L. (Menon S.r.l.). Process for Producing Lower Polyols and their Mixtures. Eur. Pat. Appl. EP 510,238 (Cl. C07C31/20), Oct 28, 1992; Appl. 91/106,862, Apr 26, 1991; Chem. Abstr. 1992, 118, 41192n. (22) Jagtap, R. N.; Malshe, V. C. Products of Hydrogenolysis as Raw Materials for Paints. Paintindia 1996, 46 (11), 25-26, 2830 (English). (23) Drent, E.; Jager, W. W. Process and Catalysts for the Hydrogenolysis of Glycerol into 1,3-Propanediol and Acrolein. PCT Int. Appl. WO 9,905,085 (Cl. C07C29/60), Feb 4, 1999; Appl. 98/ EP4,982, July 20, 1998; Chem. Abstr. 1999, 130, 126585r.

Received for review June 16, 2004 Revised manuscript received November 17, 2004 Accepted November 19, 2004 IE049473V

Kieselguhr

Recommend Documents