WIH”IN!”WWWHHIUIWIHliHlUl/HJHIWW 1 HS. #4 00 000 '-+ 3 1293 01410 2457 llllllllll'illllllllllllllllllllllllllll This is to certify that the thesis entitled A Mechanism and Selectivity Study of Sugar and Sugar Alcohol Hydrogenolysis Using 1,3-Diol Model Compounds presented by Todd David Furney has been accepted towards fulfillment of the requirements for M . S . degree in Chemical ' Engineering Major professor Date 11/15/95 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution LIBRARY Michigan State University PLACE u RETURN aoxm remove this maul My; room. TO AVOID FINES Mum on or baton dot. duo. DATE DUE DATE DUE DATE DUE ~25% } $05 1 II I l MSU I. An Minn-live Action/Ema! Opportunhy IMRWOH mm: —§'.O A MECHANISM AND SELECTIVITY STUDY OF SUGAR AND SUGAR ALCOHOL HYDROGENOLYSIS USING 1,3-DIOL MODEL COMPOUNDS By Todd David Furney A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Chemical Engineering 1995 ABSTRACT A MECHANISM AND SELECTIVITY STUDY OF SUGAR AND SUGAR ALCOHOL HYDROGENOLYSIS USING 1,3-DIOL MODEL COMPOUNDS By Todd David Furney Knowledge of the bond cleavage mechanism governing sugar and sugar alcohol hydrogenolysis is essential to control of the selectivity of sugar and sugar alcohol hydrogenolysis. Previous work by others has resulted in the suggestion of a variety of mechanisms to explain C-C cleavage in hydrogenolysis, and has not provided definitive evidence to elucidate either the C-C or C-O cleavage mechanism. In this work, a mechanism study has been carried out using 1,3-diol model compounds. The experimental results indicate that cleavage of the C-C and C-0 bonds in hydrogenolysis is through retro-aldolization and dehydration of a B-hydroxyl carbonyl, respectively. In addition to the mechanism study, a study has been carried out to determine the effects of reaction conditions and catalyst choice on the rate and selectivity of 2,4-pentanediol hydrogenolysis. It has been determined that high base concentration, high hydrogen pressure, and low catalyst concentration improve the selectivity towards C-C cleavage. ACKNOWLEDGMENTS The author wishes to thank Dr. Martin Hawley, Mr. Keyi Wang, and Mr. Scot DeAthos for their assistance in completing this project. This work was generously supported by the Consortium for Plant Biotechnology Research, the Amoco Foundation, the Michigan State University Crop and Food Bioprocessing Center, and the Department of Chemical Engineering at Michigan State University. iii TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES CHAPTER 1: INTRODUCTION 1.1 Literature Survey of Sugar Hydrogenolysis 1.2 Objectives of this Study CHAPTER 2: EXPERIMENTAL 2.1 Description of Apparatus 2.2 Experimental Procedure 2.3 Sample Analysis 2.4 Error Estimation CHAPTER 3: RESULTS AND DISCUSSION 3.1 Mechanism Study Results 3.2 Rate and Selectivity Results CHAPTER 4: CONCLUSIONS CHAPTER 5: FUTURE WORK CHAPTER 6: APPENDICES Experimental Data GC Calibration Curves Intermediate Calculations LIST OF REFERENCES iv 11 11 13 13 14 15 15 26 33 35 37 50 55 60 LIST OF TABLES Table 1-1: Petroleum-Based Feedstock and Chemical Costs for 1 lb Product Table 1-2: Sugar-Based Feedstocks for 1 lb Product Table 2-1: I-IPLC Method Summary Table 3-1: Structures of the 1,3-Diols Used in this Work Table 3-2: Mechanism Study Experimental Results 14 15 16 LIST OF FIGURES Figure 1-1: Predicted Mechanism of Sugar and Sugar Alcohol Hydrogenolysis Figure 2-1: Experimental Apparatus Figure 3-1: HPLC Trace of 2,4-dimethyl-2,4-pentanediol (1) Figure 3-2: HPLC Trace of 2-methyl-2,4-pentanediol (2) Figure 3-3: HPLC Trace of 2,2,2-tn'methyl-l,3-pentanediol (3) Figure 3-4: HPLC Trace of 2,2-dimethyl-l,3-propanediol (4) Figure 3-5: HPLC Trace of 2,4-pentanediol (5) Figure 3-6: HPLC Trace of 1,3-butanediol (6) Figure 3-7: HPLC Trace of 1,3-propanediol (7) Figure 3-8: Effect of Temperature on Conversion Figure 3-9: Arrhenius Plot to Determine Ea Figure 3-10: Effect of Pressure on Rate Constant Figure 3-11: Efl‘ect of Catalyst Type on Rate Constant Figure 3-12: Effect of Base Concentration on Selectivity Figure 3-13: Efl‘ect of Catalyst Amount on Selectivity Figure 3-14: Efl‘ect of Pressure on Selectivity Figure 3-15: Efl‘ect of Catalyst Type on Selectivity 12 17 18 20 21 22 23 23 27 27 28 29 3O 31 31 32 CHAPTER 1: INTRODUCTION Under high temperature and high hydrogen pressure, sugars and sugar alcohols can be catalytically hydrogenolyzed to give various polyols. Hydrogenolysis is catalyzed by transition metal catalysts and enhanced by addition of bases. In this process, both C-C and C-0 bonds are susceptible to cleavage: R3C-CR’3 + H; ——> R3CH + HCR’3 R3C-OH + H2 ——¢ R3CH + H20 The various products fi'om sugar hydrogenolysis include: ethylene glycol, propylene glycol, 1,3-propanediol, glycerol, 1,2-butylene glycol, 1,4-butylene glycol, and 2,3 butylene glycol. Although numerous patents related to production of these chemicals fi'om sugars have been issued, none of these processes is currently in industrial use. Of the compounds listed above, glycerol, ethylene glycol, and propylene glycol are the most industrially important. Glycerol is used in the manufacture of nitroglycerol, cosmetics, liquid soaps, liqueurs, inks, and lubricants. Ethylene glycol is used as an antifreeze in cooling and heating systems, in hydraulic brake fluids, and as a solvent in the paint and plastic industries. Propylene glycol finds use as a nontoxic substitute for ethylene glycol in a number of applications. As mentioned previously, glycerol, ethylene glycol, and propylene glycol are not currently produced on an industrial scale from sugars. Glycerol is produced from the chlorination and subsequent hydrolysis of propylene. Ethylene glycol is produced by the hydration of ethylene oxide. Propylene glycol is produced by the hydration of propylene l oxide. Each of these processes is petroleum-based and, considering the limited supply of petroleum, there is considerable economic promise to develop processes based on renewable resources such as sugars. Shown below in Tables 1-1 and 1-2 is a comparison of the prices of feedstocks and chemicals for production of one pound each of ethylene glycol, propylene glycol, and glycerol for both a petroleum-based process (Table 1-1) and a sugar based process (Table 1-2). Yields for each step of the petroleum based processes are from Lowenheim and Moran (1985). Chemical prices are from Chemical Marketing Reporter. A sugar conversion of 50 % was assumed. Table 1-1: Petroleum-Based Feedstock and Chemical Costs for 1 1b Product Product F eedstock/Chemical Amount required Cost Total Cost 1 ethylene glycol ethylene (5.16/lb) .9 lb 5.144 5.144 propylene glycol propylene (5.18/lb) .94 lb 5.169 chlorine (5.11/lb) 1.6 lb 5.176 lime (5.06/lb) 1.1 lb 5.066 5.411 glycerol propylene (5.18/lb) .63 lb 5.113 chlorine (5.11/lb) 2 lb 5.22 lime (5.06/1b) .45 lb 5.027 NaOH (5.30/lt9 .45 lb 5.135 5.495 Table 1-2: Sugar-Based Feedstock Costs for 1 lb Product Product Feedstock Amount required Cost Total Cost ethylene glycol sugar (5.15/lb) 1.91 lb 5.287 5.287 propylene glycol sugar (5.15/lb) 2.34 lb 5.351 5.351 glycerol sugar (5.15/lb) 2 lb 5.300 5.300 As can be seen from the tables above, sugar-based processes have excellent potential to compete with petroleum-based processes. Glycerol and propylene glycol are promising even at today’s petroleum prices. The most important reason that sugar hydrogenolysis is not currently an industrially important process is poor selectivity. Since a sugar molecule contains many C-C and C-0 bonds which are susceptible to cleavage, a wide distribution of products may result under hydrogenolysis conditions, rendering the process uneconomical. In order for a sugar hydrogenolysis process to be economically viable, the selectivity towards the most highly valued compounds must be greatly increased. 1.1 Literature Survey of Sugar Hydrogenolysis Although the sugar hydrogenolysis reaction was discovered as early as the 1930’s (Zartman, 1932), research for the purpose of biomass conversion has only been carried out since the 1950’s. In one of the early reports, Clark (1958) reported obtaining glycerol in up to 40% yields fi'om sorbitol. In his experiments, nickel on kieselguhr was the catalyst and calcium hydroxide was the base. Reactions were carried out in the aqueous phase at temperatures between 215 and 240 C and hydrogen pressures between 2000 and 5600 psi. Besides glycerol, other identified products included propylene glycol, ethylene glycol, erythritol, and xylitol. In 1960, Boelhouwer et a1. obtained high yields (up to 75 %) of distillable polyalcohols in hydrogenation experiments utilizing sucrose as the raw material with COpper chromite catalysts activated with beryllium oxide. Experiments were performed in a rotating autoclave with methanol being used as the solvent. The reaction products were separated by distillation. In one experiment, the glycerol fraction was reported to account for 61 % of the product. However, since this fraction covers a wide range of boiling points (120- 210 C @ 20 mm), other products in addition to glycerol are certainly included. Using a newly developed quantitative gas-liquid chromatographic method for product analysis, Van Ling et a]. (1970) investigated several continuous reactor configurations for the catalytic high pressure hydrogenolysis of sucrose to glycerol. In contrast to previous batch experiments (Van Ling, 1967) in which yields of 40 weight % glycerol were obtained using CuO-CeOz-Sioz as a catalyst, poor yields resulted fiom both a tubular reactor (<20 weight %) and a series of two continuous stirred tank reactors (30 weight %). The low yield for the tubular reactor was explained as being caused by poor mixing of reactants resulting in inadequate transport of hydrogen to the catalyst surface. Several reasons were given for the low yield from the series CSTR arrangement. Among them were: presence of lactic acid formed during the reaction causing an accelerated hydrolysis of sucrose to glucose and fi'uctose, lower concentration of base than in the batch reactor, and residence time distributions in the CSTR causing increased conversion of glycerol to propylene glycol. As previously discussed, both C-C and C-0 bonds in sugars and sugar alcohols are subject to cleavage under hydrogenolysis conditions. The mechanism of these cleavages has been interpreted in a variety of ways by different researchers. Cleavage of C-0 bonds has been proposed by Montassier, et al. (1988 and 1989) to occur through dehydration of a B—hydroxyl carbonyl: OH OH OH OH $142 I I i +H2 I RCHCIJH HR'—-—> ROCHCHR'; R C=CHR'—»RCHCHCH2R' OH OH OH OH The structure of this B-hydroxyl carbonyl is already contained in an open-chain sugar molecule, and may be generated from a sugar alcohol by dehydrogenation. The direct product fi'om dehydration of the B-hydroxyl carbonyl is an or,B—unsaturated carbonyl, which yields a polyhydric alcohol upon hydrogenation. In this reaction scheme, the dehydration step is catalyzed by bases, while the dehydrogenation and hydrogenation steps are catalyzed by transition metal complexes. The original mechanism proposed by the Montassier group ( Sohounloue, 1983) to explain C-C cleavage in sugar and sugar alcohol hydrogenolysis is the retro-aldol reaction: OH OH I | . 4+2 I I Retro II II +++2 l Rcuclsucm —» RCCIS Home? RCCHzOH + HCR' —> RCHCHzOH + HOCHzR' OH OH Andrews and Klaren (1989) suggested the same mechanism, based on their observation that the primary C-C cleavage site is B to the carbonyl group in sugar hydrogenolysis. According to this mechanism, the C-C cleavage precursor is again a B—hydroxyl carbonyl. Cleavage of this B—hydroxyl carbonyl leads to an aldehyde and a ketone, which are subsequently hydrogenated to alcohols. Later, however, Montassier et. a1. (1988) found that it was difficult to explain the absence of methanol and the presence of C02 in the hydrogenolysis products of glycerol and other sugar alcohols with the retro-aldol mechanism. Therefore, they proposed another mechanism, namely the retro-Claisen reaction, for the C-C cleavage in glycerol hydrogenolysis: /H OH OH O O 0 O 0 OH OH I I -2H2 II II I) Lu Rm CHchCH2—> HCCHCH—> HO—c m c ___.H OH + CH=CH I I H/ \CH/ \H Claisen OH JOH H20 I OH This mechanism allows formation of formic acid which decomposes under hydrogenolysis conditions to form C02. The mechanism based on the retro-aldol reaction predicts formation of formaldehyde rather than formic acid. Upon hydrogenation, formaldehyde yields methanol. To explain the C-C cleavage in the hydrogenolysis of xylitol and sorbitol, Montassier et al. also proposed the retro-Michael reaction as the mechanism: OH OH O O (r o l I ~2H2 II II Retro I ll ROHpHcleclecHR'——> RC H HCHCR’ m Rccls=<|3H + OHCHch' OHOHOH OHOHOH OH OH This mechanism requires a 8-dicarbonyl as the bond cleavage precursor. 1.2 Objectives of this Study Although three difi‘erent mechanisms have been proposed to explain C-C cleavage in the hydrogenolysis of sugars and sugar alcohols, tWo theoretical considerations make the retro-Claisen and retro-Michael mechanisms unlikely to be a dominating C-C cleavage mechanism. First, both the retro-Claisen and retro-Michael mechanism require a dicarbonyl precursor. The formation of a dicarbonyl presumably occurs through further dehydrogenation of a monocarbonyl. Since the dehydrogenation is thermodynamically unfavorable, the dicarbonyl formed is unlikely to be present in significant amounts relative to the monocarbonyl, the precursor of the retro-aldol reaction. Second, the dehydrogenation Of the monocarbonyl is in competition with dehydration, the C-0 cleavage reaction. Since the dehydration is both thermodynamically and kinetically (in the presence of bases) much more favorable than the dehydrogenation, the hydrogenolysis products would result almost exclusively from C-O cleavage if either the retro-Claisen or retro-Michael mechanism is the dominating mechanism. In contrast to the other two proposed C-C cleavage mechanisms, the retro-aldol mechanism shares the same precursor as the dehydration, and has the ability to compete with dehydration. Based on these theoretical considerations, C-C cleavage most likely occurs through the retro-aldol reaction and the bond cleavage process in sugar and sugar alcohol hydrogenolysis can be pictured as in Figure 1-1. As for the formic acid produced in the hydrogenolysis of glycerol which led Montassier et a1. (1988) to suggest the retro-Claisen mechanism, it may be produced from the Cannizzaro reaction of formaldehyde. In the Cannizzaro reaction, formaldehyde is oxidized to formic acid while other carbonyl compounds are reduced to alcohols. This reaction is catalyzed by bases but has been reported to be greatly enhanced by transition metal co-catalysts (Cook and Mailis, 1981). The Cannizzaro reaction enhanced by the transition metal is likely to be the side reaction competing with the hydrogenation of O O OH II II +H 2 I RCCHzOH + HCR' ——-> RCHCHzOH + HOCHzR' retro- aldol OH OH O OH | I -H2 II | RCH(|3HCHR’ RCCIIHCHR' OH OH -H20 0 OH H +H2 I RCCIJ=CHR' —> RCHCHCHzR' OH OH Figure 1-1: Predicted Mechanism of Sugar and Sugar Alcohol Hydrogenolysis formaldehyde in the hydrogenolysis of glycerol and other sugar alcohols, which is responsible for the absence of methanol and the presence of carbon dioxide in the hydrogenolysis product. The reaction mechanism described in Figure 1-1 can explain all the reaction products found so far in the hydrogenolysis products of sugars and sugar alcohols. Other than that, the results provide no clue that the C-0 bond is broken through dehydration of a [3— hydroxyl carbonyl. Experimental evidence that dehydrogenation is a necessary step in the hydrogenolysis of sugar alcohols is also unavailable, and no sugar intermediate has been identified in any of the sugar alcohol hydrogenolysis experiments. Andrew and Klaren’s (1989) observation that the primary C-C cleavage site is B to the carbonyl group in sugar hydrogenolysis may be a strong suggestion that the C-C cleavage has occurred through the retro-aldol reaction. However, bond breakage at this site is also expected by the retro- Claisen mechanism. Clearly, more evidence is required to validate the mechanism described in Figure 1-1. In order to determine the mechanism of sugar and sugar alcohol hydrogenolysis, a study using 1,3-diols with a variety of structural features has been carried out. The use of 1,3-diol model compounds has several advantages over direct use of sugar or sugar alcohol compounds. First, with 1,3-diols, the bond cleavage pattern is indicated by the reaction products since the starting molecule is capable of undergoing only one bond breaking reaction. In contrast, sugars and sugar alcohols can undergo a series of bond breaking reactions before fiirther hydrogenolysis is impossible. As a result, the bond cleavage pattern is difiicult to recognize based on the final product distribution. Second, sugar and sugar alcohols have too many firnctional groups, which makes it possible to . interpret the experimental results in a variety of ways. Unlike sugars and sugar alcohols, 1,3-diols possess only the fiinctional groups necessary for hydrogenolysis to occur, which minimizes the ways to interpret the results. For example, the retro-Michael mechanism is excluded from the hydrogenolysis of 1,3-diols because they are incapable of forming the 5- dicarbonyl bond cleavage precursor. Last and most important, 1,3-diols with special structural features can be used to verify the role played by a single reaction in the hydrogenolysis. In addition to determining the mechanism of sugar and sugar alcohol hydrogenolysis, a Study has been carried out to determine the effect of reaction conditions on the rate and 10 selectivity of 2,4-pentanediol hydrogenolysis. In addition to examining the role of a variety of types of catalysts, the effect of hydrogen pressure, reaction temperature, base concentration, and catalyst concentration has been analyzed. CHAPTER 2: EXPERINIENTAL 2.1 Description of Apparatus In this work, a series of 1,3-diols have been used as model compounds to study the reaction mechanism and factors affecting selectivity control of sugar and sugar alcohol hydrogenolysis. All experiments were carried out in a 50 ml, stainless steel reactor. A diagram of the apparatus is presented below in Figure 2-1. Samples were taken during the course of the reactions through a sampling port. The sampling system consists of a 0.5 um pore size stainless filter submerged in the reaction medium, 1/ 16 in. stainless tubing, and a valve. The filter prevents the passage of solid catalyst particles into the sampling system. Components of the sampling system were chosen to reduce dead volume, insuring that samples represented the current contents of the reactor. Hydrogen was supplied to the reactor through a hydrogen cylinder. The regulator on the cylinder was used to control the hydrogen pressure at a constant level during the course of the reaction. An additional pressure gauge was added to the hydrogen supply line to monitor the pressure near the reactor. The desired reaction temperature was maintained in a silicone oil bath with a 1000 W heating coil. The temperature was controlled with a proportional temperature controller and platinum RTD probe. In order to keep a uniform temperature distribution within the Oil bath, a nitrogen stream was bubbled through the bath. 11 12 To Temperature T S . V ._" 4—— Hydrogen, Vacuum Controller "——_ o amplmg alve I F‘— Nitrogen Thermometer——> r I“ r 2 i u I I i I WHNI Av WWVA v 1I——Oi1Level I I _ I I (I I I I I I I I I I I I I I I I I I I rL‘t I.-- 1" Filter .. _ Stainless Steel U ' Vessel O O o O O O Figure 2-1: Experimental Apparatus 13 The reaction mixture was kept well-mixed by means of a magnetic stirring bar. The entire reactor assembly was placed on a magnetic stir plate to provide magnetic power to the stirring bar. 2.2 Experimental Procedure After adding the appropriate amounts of starting diol, catalyst, base, and distilled water to the reactor, the reactor was purged with a low pressure hydrogen stream. After purging, the reactor was charged to approximately 2 MPa hydrogen pressure. Next, the reactor was heated to the desired reaction temperature, a process which took about fifteen minutes. After reaching the reaction temperature, the remainder of the desired hydrogen pressure was applied and a timer was started. Most reactions were run for about four hours with samples being taken every half hour. When sampling, the initial .5 ml of liquid was discarded to account for the dead volume of the sampling system, and the next 1-2 ml was collected for analysis. 2.3 Sample Analysis Samples were analyzed with both high performance liquid chromatography (HPLC) and gas chromatography (GC). Most of the work on the mechanism was done with HPLC, while the selectivity study samples were analyzed with GC because of a need for greater quantitative accuracy. The HPLC column used in this work is a 25 x .46 cm C18 column purchased fiom Whatman. The detector used is a differential refractometer. It was necessary to develop an _l4 HPLC method (choice of mobile phase, temperature, flow rate) for each of the seven starting diols used in the mechanism study in order to adequately separate all of the reaction products. The methods chosen are summarized below in Table 2-1. Table 2-1: HPLC Method Summary Startinggiol Temperature Solvent Flow (ml/min) 2,4-pentanediol 40 C 42 % MeOH / H20 0.8 1,3-butanediol 60 C 3 % ACN / H20 1.2 2,2,4,-trimethyl-l,3-pentanediol 40 C 25 % ACN / H20 2.0 2-methyI-2,4-pentanediol 40 C 42 % MeOH / H20 0.8 2,4-dimethyl-2,4-pentanediol 40 C 25 % ACN / H20 1.5 2,2-dimethyl-1,3-propanediol 60' C 10 % ACN / H20 1.5 1,3-propanediol 60 C 0.3 % ACN / H20 1.5 The GC column used in the selectivity study is a DB624 column purchased from 1&W Scientific. The detector used is a flame ionization detector. The following temperature program was found to separate all 2,4-pentanediol hydrogenolysis products: one minute at 40 C followed by a 40 C / minute temperature rise until all products were eluted. Calibration curves for each of the products may be found in Appendix 6.1. 2.4 Error Estimation In order to reduce error in the calculations, all reaction samples were run twice and calibration curve samples were run three times. By comparing the differences in integration areas for different runs of the same sample, an average error of about 5 % was calculated. Thus, the calculated concentrations are estimated to be accurate +/- 5%. CHAPTER 3: RESULTS AND DISCUSSION 3.1 Mechanism Study Results In order to verify the mechanism described in Figure 1-1, hydrogenolysis experiments have been performed with 1,3-diols of various structures. The 1,3-diols used include: 2,4- dimethyl-2,4-pentanediol (l), 2-methyl-2,4-pentanediol (2), 2,2,4-trimethyl-1,3- pentanediol (3), 2,2-dimethyl-l,3-propanediol (4), 2,4-pentanediol (5), 1,3-butanediol (6), and 1,3-propanediol (7). The structures of these compounds are shown in Table 3-1, while the experimental results are shown in Table 3-2. Table 3-1: Structures of the 1,3-Diols Used in this Work Name R1 R2 R3 R4 R5 R6 2,4-dimethyl-2,4-pentanediol CH3 OH; H H CH3 CH3 2-methyl-2,4-pentanediol CH3 CH3 H H H CH3 2,2,4-trimethyl-1,3-pentanediol H H CH3 CH3 H CH(CH3)2 2,2-dirnethyl-l,3-propanediol H H CH3 CH3 H H 2,4-pentanediol CH3 H H H H CH3 1,3-butanediol H H H H H CH3 1,3-propanediol H H H H H H OH R4 OH “"ia—irir‘“ R2 R3 R5 All the experiments in the mechanism study have been carried out at 210 C under 5 MPa H2 pressure in the aqueous phase. NaOH was added to promote the reaction. 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The reason is attributed to the transition-metal-catalyzed Cannizzaro reaction, which intercepts formaldehyde, the hydrogentaion precursor to methanol, as discussed earlier. According to Figure 1-1, the hydrogenolysis of a 1,3-diol is initiated by dehrogenating one of its hydroxyl groups. This postulation is strongly supported by the results from the 1 1. 2,4—dimethyl-2,4—pentanediol i. impurities d. solvent disturbance :‘JIJI ' O 5 10 15 20 Retention time (min) Figure 3—1: HPLC Trace of 2,4-dimethyl-2,4-pentanediol (1) hydrogenolysis of 1. Because of the absence of a hydrogen atom on bothe the a and y carbons, l is incapable of undergoing dehydrogenation, and thus is expected to be inactive under hydrogenolysis conditions. As indicated by Figure 3-1, 1 is indeed found to be 18 inactive. The hydrogenolysis of 1 has been carried out for six hours with Raney Cu as the catalyst (Run 1) and four hours with Raney Ni as the catalyst (Run 8). No reaction products have been identified at the end of either reaction. For comparison, other 1,3-diols used in this study were all found to reactive under the same conditions, because they can undergo the dehydrogenation reaction. That dehydrogenation is a necessary step for hydrogenolysis is additionally supported by the results from the hydrogenolysis of 2. Since 2 can not be dehydrogenated at the a carbon, the C-C and C-0 bonds of 2 are not expected to be broken between the B and y carbons and the 7 carbon, respectively, during hydrogenolysis, although they may be broken between the or and B carbons and at the a 1. acetone 2 2. isopropanol 3 3. 2-methyl-2,4-pentanediol 4. 4-methyl-2-pentanol d d. solvent disturbance i. impurity i _/H IIIUI 4 0 5 10 15 Retention time (min) Figure 3-2: HPLC Trace of 2-methyl-2,4-pentanediol (2) carbon, respectively. The experimental results again turned out precisely as expected (Figure 3-2). The results fiom hydrogenolysis of 2 also provide good evidence against the retro- Claisen reaction as the dominating C-C cleavage mechanism. The retro-Claisen reaction 19 requires a dicarbonyl precursor. Since 2 is incapable of forming such a dicarbonyl, the retro-Claisen mechanism predicts that the C-C bonds of 2 are unbreakable under hydrogenolysis conditions. However, the experimental results show otherwise: the hydrogenolysis rate of 2 is not impaired by its incapability of undergoing the retro-Claisen mechanism, as shown by the conversion data in Table 3-2. In contrast to the retro-Claisen mechanism, the retro-aldol mechanism predicts that the C-C bond of 2 may be broken between the or and B carbons to form two isopropanol molecules, since 2 can be dehydrogenated at the 7 carbon. The retro-aldol mechanism also predicts that the isopropanol formed is formed through an acetone intermediate. As seen in Figure 3-2, isopropanol is found not only at the end of the reaction, but is a dominating product of 2-methyl-2,4-pentanediol hydrogenolysis. Furthermore, acetone is identified in the reaction when Raney Cu is used as the catalyst (Run 2). Acetone is not detected in the reaction when Raney Ni is used as the catalyst (Run 9) because Raney Ni is a more efficient catalyst of hydrogenation than Raney Cu and quickly hydrogenates the acetone to isopropanol. The results from the hydrogenolysis of 3,4,5,6, and 7 are also supportive of the retro- aldol mechaniSm. In all these experiments, the C-C bond cleavage patterns are found to be consistent with the retro-aldol mechanism. In the hydrogenolysis of 6 (Run 6), acetone is again identified as an intermediate, as predicted by the retro-aldol mechanism. Hydrogenolysis of 2,6, and 7 has been carried out by Conner and Adkins (1932) with a catalyst prepared by precipitation of Ni carbonates. However, in the hydrogenolysis of 2, they identified only the end products, isopropanol and 4-methyl-2-pentanol, as in Run 9. 20 In the hydrogenolysis of 6 and 7, they did not report the C-C cleavage at all. The successfiil identification of C-C bond cleavage in hydrogenolysis of 6 and 7 and of the retro-aldol interrnediatesin hydrogenolysis of 2 and 6 in this study strengthens the theory that the C-C cleavage occurs through the retro-aldol reaction. Also according to Figure 1-1, the dehydration reaction is responsible for the C-0 cleavage in hydrogenolysis. This postulation is strongly supported by the results from the hydrogenolysis of 3 and 4. Based on the dehydration mechanism, a hydrogen atom attached to the B carbon is necessary for the hydrogenolysis of C-0 bonds to occur. Since such a hydrogen does not exist in 3 and 4, cleavage is not expected to occur in the 2 l. methanol 2. isobutanol 3 3. 2,2,4—trimethyl-l,3-pentanediol 4. 2,4—dimethyl-3-pentanol i. impurity \ 4 f A~— ‘1 fi ‘ l\__ O 2 4 6 8 10 12 Retention time (min) Figure 3-3: HPLC Trace of 2,2,4—trimethyl-1,3-pentanediol (3) 21 2 l. methanol 2. 2,2-dimethyl-1,3-propanediol 3. isobutanol i. impurities d. solvent disturbance , 1 I ¢ d i 3 3 "2 i I. a Retention time (min) Figure 3-4: HPLC Trace of 2,2-dimethyl-1,3-propanediol (4) hydrogenolysis of these compounds. Indeed, as indicated in Table 3-2, no C-O cleavage is found in the hydrogenolysis of either 3 or 4. The dehydration mechanism is also supported by the C-0 cleavage pattern found in the hydrogenolysis of 2 (Runs 2 and 9). The dehydration mechanism expects the C-0 bond to be broken only at the or carbon in the hydrogenolysis of 2, since 2 can be dehydrogenated only at the 7 carbon. The results from the hydrogenolysis of 2, show that this expectation is correct. The additional products 2-pentanone and 2-butanone identified in the hydrogenolysis of 5 (Runs 5 and 12) and 6 (Run 6), respectively, provide additional evidence to the dehydration mechanism. These compounds are not the direct products of 22 dehydration, but intermediates. The hydrogenation is believed to take place in two sequential steps, as shown in the following with the hydrogenolysis of 5 as an example: 0 O OH ll +H2 || +H2 | CH3CH=CHCCH3 —->CH3CH2CH2CCH3 ——-> CH3CH2CH2CHCH3 3-pentene-2-one 2-pentanone 2-pentanol The accumulation of 2-pentanone in the hydrogenolysis of 5 and of 2-butanone in the hydrogenolysis of 6 suggests that, with Raney Cu and Ni as catalysts, the hydrogenation of C=C double bonds is faster than the hydrogenation of C=O double bonds. 1. ethanol 2 4. 2-pentanone 2. 2,4—pentanediol H _ 5. 2-pentanol 3. isopropanol i. impurities d. solv disturbance 4 d 3 5 ' 1 i 2 4 6 8 10 Retention time (min) Figure 3-5: HPLC Trace of 2,4-pentanediol (5) As previously discussed, the hydrogenolysis mechanism described in Figure 1-1 is strongly supported by the results from the hydrogenolysis of the various 1,3 diol model compounds. In no reaction has a product other the expected been found, and in 23 l. methanol 3 2. ethanol 3. 1,3-butanediol 4. acetone 5 5. isopropanol 6. 2-butanone 7. 2-butanol 8. n-butanol i. impurity u. unidentified 10 15 20 Retention time (min) Figure 3-6: HPLC Trace of 1,3-butanediol (6) 2 1. methanol 2. 1,3—propanediol 3. ethanol 4. n-propanol i i. impurity 1 4 i l 3 O 2 4 6 8 1O 12 Retention time (min) Figure 3-7: HPLC Trace of 1,3-propanediol (7) 24 no reaction has an expected product not been found. The experiments in this work have been performed with two difl‘erent catalysts. The reaction patterns are not affected by the cahnge of catalyst. Compared to Raney Cu, Raney Ni is a more efficient hydrogenolysis catalyst, as shown by the conversion data in Table 3-2. In addition to the bond cleavage mechanism, selectivity control is another important issue concerning sugar and sugar alcohol hydrogenolysis. In the hydrogenolysis of a 1,3- diol, four typical bond cleavage selectivities may be defined, namely; Ca—Cg vs. Ca—O, CB— C, vs. Cy—O, Ca—Cp vs. Cp—C.,, and Ca—O vs. Cy—O. According to Figure 1-1, the retro- aldol reaction responsible for the C-C cleavage and the dehydration reaction responsible for the C-0 cleavage share the same precursor. Compared to the hydrogenation reactions catalyzed by Raney Cu and Raney Ni, the retro-aldol and dehydration reactions require only moderate reaction conditions. It is believed that, in the hydrogenolysis of 1,3-diols, the retro-aldol and dehydration reactions are basically in an equilibrium state. Therefore, the C-C vs. 00 selectivities are determined by the equilibrium constants between the retro-aldol products and the dehydration products and by their relative hydrogenation rates. In general, for straight chain 1,3-diols, the equilibrium favors the dehydration product; ' while for branched chain 1,3-diols, the equilibrium favors the retro-aldol product (Neilson and Houlihan, 1968). With Raney Cu as the catalyst, the C-C vs. C-O selectivity is basically controlled by the equilibrium between the retro-aldol and dehydration products, as shown by the C-C vs. 00 selectivity data in Table 3-2. In the hydrogenolysis of 2 ( a 25 branched chain 1,3-diol), the reaction favors the C-C cleavage; while in the hydrogenolysis of 5 and 7 (straight chain 1,3-diols), the reaction favors the C-0 cleavageCompared to the Raney Cu catalyst, Raney Ni seems to direct the reaction more towards C-C cleavage. In the hydrogenolysis of 2, the C-C cleavage relative to C-0 cleavage is further enhanced; in the hydrogenolysis of 5 and 7, the C-C and C-0 cleavage are equally favored, although the equilibrium between the retro-aldol and dehydration products still favors the latter. Based on the above results, Raney Ni must hydrogenate the retro-aldol products faster than it hydrogenates the dehydration products. In dealing with the Ca—Cp vs. Cp—C., and the Ca—O vs. Cy—O selectivities, an additional factor, the dehydrogenation must be considered, besides the retro-aldol and dehydration reactions. In the hydrogenolysis of 3, the Ca—Cp vs. Cp—C, selectivity seems to be controlled by the retro-aldol reaction when Raney Cu is used as the hydrogenolysis catalyst. The retro-aldol reaction favors the C3-C7 substantially over the Ca—Cp cleavage in this case. When Raney Ni is used as the catalyst, this selectivity can not be explained based purely on the retro-aldol reaction, because cleavage of the two carbon bonds is almost equally favored. A logical conclusion seems that, with Raney N: as the catalyst, the dehydrogenation of a secondary hydroxyl group as favored over that of a primary hydroxyl group. Steric efi‘ects also play an important role in determining selectivities. For example, in the hydrogenolysis of 6, Ca-Cp cleavage dominates over C9-C7 cleavage and Ca-O cleavage dominates over Cp-O cleavage. These results are consistent with the fact that the a-carbon and hydroxyl are much less sterically hindered than the B-carbon and hydroxyl. 26 When the retro-aldol reaction occurs, the aldol reaction is also possible, which often leads to scrambling of the retro-aldol products. Thus, in the hydrogenolysis of 1,3-diols, one might expect 1,3-diols other than the starting ones to be formed as a result of the scrambling aldol reaction. However, no such by-products have been observed in any experiment carried out in this work. The reason is attributed to the fast hydrogenation of aldehydes under the hydrogenolysis conditions and the unfavorable condensation between ketones, which minimize the formation of any new 1,3-diols. 3.2 Rate and Selectivity Study Results In this work, 2,4-pentanediol has been used as a model compound to investigate the effects of several reaction conditions (temperature, hydrogen pressure, base concentration, catalyst concentration, and catalyst type) on reaction rate and selectivity. 2,4-pentanediol Conversion Rate Three of the reaction variables studied were found to have a significant effect on the rate of 2,4-pentanediol hydrogenolysis, namely: temperature, hydrogen pressure, and catalyst type. The range of base and catalyst concentration studied was not found to significantly afi‘ect the rate. (1) Effect of Temperature The course of the hydrogenolysis reaction has been followed by plotting the natural logarithm of 2,4-pentanediol unconverted (l-X) vs. reaction time at three difi‘erent temperatures. The best possible straight line was drawn using regression analysis to represent the overall rate as a psuedo-first order reaction: 27 -r,, = -dCa/dt = kaCa The results are presented below in Figure 3-8. The slope of each of the lines is -k,,. As expected, higher It, is obtained at higher temperatures. ' T-ZOOC ‘3 TSZZOC ’ T-Z4OC In l1-Xl C=.250RmeyCu l-P-SM". B-.2ni1NNnOH 4.2 1 i f 0 50 1d) 150 200 250 Tin-hi!) «r dL Figure 3-8: Efi'ect of Tempertature on Conversion .05 4- .‘ .5 4i- hK -2.5 ~- -3 t t i : t : e v . 0.00194 0.00196 0.00198 0.002 0.00202 0.00204 0.00200 0.00208 0.0021 0.00212 1 [TIM Figure 3-9: Arrhenius Plot to Determine Ea 28 Figure 3-9 shows that 2,4-pentanediol hydrogenolysis closely follows Arrhenius’ Law using Raney Cu as the catalyst. From the slope of the plot of In ka vs. T", the activation energy was determined to be 66 kJ mol'l, estimated to be accurate within about 5 %. (2) Effect of Presssure The effect of hydrogen pressure on the rate of hydrogenolysis is illustrated in Figure 3- 10. The rate constant, ka, decreases with increasing hydrogen pressure. The natural log of kg was plotted vs. the natural log of the pressure yielding a slope of -l .4. Consequently, the rate of 2,4-pentanediol hydrogenolysis is -1.4 order with respect to hydrogen pressure. (3) Effect of Catalyst Type The effect of catalyst type on the rate of hydrogenolysis is shown in Figure 3-11. In order from most to least active, the catalysts studied are: Nickel on Silica/Alumina, Ni on Kieselguhr, Raney Ni, and Raney Cu. °1 -0.5 “r -1 2 -1.5 a~ -2 a. I -2.5 L -3 a1- I .35 h -4 1 4. 1 4 1 1 1 1 1 1 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 hP Figure 3-10: Efi‘ect of Pressure on Rate Constant 29 ‘0.2 N O 0.4 ~~ - O ' Ni on K 0.6 a ’ a. - D . ’5 D D . N1 on S E O 8 d _ ' ’ Raney Ni - r3 ’1 ‘” . '0 Raney Cu I 1.2 a D 1.4 - . T = 220 0 HP = 5 MPa 16 , T , , B=.2ml1NNaO 0 so 100 150 200 250 c = '25 9 Time (min) Figure 3-11: Efi‘ect of Catalyst Type on Rate Constant 2,4-peutanediol Selectivity Study Results Four of the reaction variables studied were found to have a significant effect on the selectivity of 2,4-pentanediol hydrogenolysis, namely: base concentration, catalyst concentration, hydrogen pressure, and catalyst type. Variation in temperarure was not found to significantly affect the selectivity. In each of the plots that follows, selectivity has been defined as the ratio of C-C cleavage to C-0 cleavage. (1) Efi‘ect of Base Concentration As illustrated in Figure 3-12, a higher base concentration leads to a dramatically 30 improved selectivity. Andrews (1989) has suggested that improved selectivity obtained fi'om increased base concentration may involve attack of the alkoxide ion on the catalytic complex which is known to provide a catalyst capable of efficient ketone hydrogenation. 1.8 4— o o . o . . o ’ 1.6 + 1.4 ~~ D 1.2 -- C] >. D D - 0 ml 5 1 ._ a D a D 13 D .2 ml 3 0.8 T ° .5 ml 0.6 —» 0.4 —~ - . I I I I I ' 0.2 4~ 0 1 l r 1 J1 0 50 100 150 200 250 Time (min) Figure 3-12: Effect of Base Concentration on Selectivity (2) Effect of Catalyst Amount Figure 3-13 illustrates that improved selectivity is obtained when a smaller amount of catalyst is used. (3) Effect of Hydrogen Pressure Figure 3-14 illustrates that increased hydrogen pressure results in improved selectivity, although the efi‘ect is not as pronounced as with the other reaction variables considered. (4) Efl‘ect of Catalyst Type 31 Figure 3-15 shows that the type of catalyst chosen has an important effect on selectivity. Ranked in order from most selective to least selective the catalysts are: Raney Cu, Raney Ni, Ni on Kieselguhr, and Ni on Silica/Alumina. Selectivity Selectivity UI I ' I I D D a ' . :1 o c: 10 g . D O .25 g o . . .50 a O O ’ o o 50 100 150 200 250 Time (min) Figure 3-13: Efi‘ect of Catalyst Amount on Selectivity . O O O O E: . - I (:1 1:1 :1 C1 3 MPa ' a D 5 MP0 I " o 7 MP3 I I so 100 150 200 250 Time (min) Figure 3-14: Effect of Pressure on Selectivity Selectivity d d d d d d d d d e e I e e e I e a —‘ -‘ N w h 0" O) \J m (D N 1 L L L l 1 l J I T I Y ‘ V I I ' 1 32 C] 0 Ni on K Ni on S Raney Ni Raney Cu 5 ' - a g, ' ' 5 50 100 1 50 200 250 Time (mini Figure 3-15: Efl‘ect of Catalyst Type on Selectivity CHAPTER 4: CONCLUSIONS In this work, a mechanism study has been carried out on the hydrogenolysis of sugars and sugar alcohols using 1,3-diols as model compounds. To summarize the experimental results, the hydrogenolysis of 2,4-dimethyl-2,4-pentanediol and 2-methyl-2,4-pentanediol demonstrates that dehydrogenation is a necessary step in the hydrogenolysis of sugar alcohols. The hydrogenolysis of 1,3-dimethyl-l,3-propanediol and 2,2,4-trimethyl-1,3- pentanediol demonstrates that dehydration is responsible for 00 cleavage in hydrogenolysis. The hydrogenolysis of 2-methyl-2,4-pentanediol also provides good evidence that the retro-Claisen mechanism is not a dominating C-C cleavage mechanism. In all of the experiments except the hydrogenolysis of 2,4-dimethyl-2,4-pentanediol, where no reaction is supposed to occur, the C-C cleavage is found to follow the patterns predicted by the retro-aldol mechanism. In addition, some of the ketone intermediates expected by the retro-aldol mechanism have been identified in the hydrogenolysis of 2- methyl-2,4-pentanediol, 2,4-pentanediol, and 1,3-butanediol. The experiments have been performed with two difl‘erent catalysts (Raney Cu and Raney Ni), the reaction patterns are not afl‘ected by the change of catalyst. All of these results suggest that the mechanism described in Figure 1-1 is correct. In addition to the mechanism study, a study has been carried out to determine the role of catalyst type and operating conditions on hydrogenolysis rate and selectivity. The catalysts chosen for study included; Raney Cu, Raney Ni, Ni on Kieselguhr, and Ni on 33 34 Silica / Alumina. The operating conditions studied were; catalyst amount, hydrogen pressure, base amount, and temperature. The rate of 2,4-pentanediol hydrogenolysis was found to be significantly increased by high temperature and low hydrogen pressure. The catalysts, ranked in order fi'om most to least active, are; Ni on Silica / Alumina, Ni on Kieselguhr, Raney Ni, and Raney Cu. Catalyst and base amount were not found to significantly affect the rate for the range of conditions studied. The selectivity of 2,4-pentanediol hydrogenolysis was analyzed by comparing the ratio of C-C cleavage to C-0 cleavage. Since C-C cleavage in a sugar or sugar alcohol molecule can result in the formation of glycerol, a high C-C / C-O selectivity is desirable. Glycerol is the most valuable of the polyols typically obtained from sugar and sugar alcohol hydrogenolysis. Improved C-C / C-O selectivity was obtained fi'om high base concentration, small catalyst amount, and high hydrogen pressure. Temperature was determined not to have a significant effect on selectivity. The catalysts, ranked in order from most to least selective, are; Raney Cu, Raney N1, Ni on Kieselguhr, and Ni on Silica / Alumina. CHAPTER 5: FUTURE WORK Many possibilities exist for future work on topics related to this project. With detailed knowledge of the reaction mechanism and the factors affecting selectivity and conversion in sugar and sugar alcohol hydrogenolysis, it should be possible to develop a rational approach to control of the selectivity of sugar hydrogenolysis. Work should be continued with model compounds at standardized conditions. Only four of the catalysts typically used in hydrogenolysis were studied in depth. In addition to the heterogenous catalysts studied so far, homogenous catalysts should also be examined. Another strategy that should be explored is development of a catalyst capable of preferentially hydro genating carbonyls over a,B-unsaturated carbonyls. Such a catalyst would be able to improve the ratio of C-C to C-0 cleavage by shifiing the equilibrium toward retro-aldolization and away from dehydration. Although there have been some reports in the literature of catalysts selectively hydrogenating ketones in the presence of compounds containing olefinic double bonds, there are no reports of selective hydrogenation in the presence of a,B-unsaturated ketones. Another important step is to apply the findings regarding improved selectivity through choice of catalyst and operating conditions to an actual sugar or sugar alcohol molecule. A variety of starting materials such as fructose, glucose, and sorbitol should be examined. Although glucose is the most abundant sugar obtained fi'om biomass, it can be easily 35 36 converted to other sugars if these other sugars should happen to lead to improved selectivity. APPENDICES 37 Experiment #107 Title: 2.4-pentanediol Hydrogenolysis with Ni on Kieselguhr Date: 6—15-95 Reaction Conditions Temperature: 210 C Pressure: 3.5 MPa Amount Substrate: 2.4-pentanediol .4946 g Solvent: water 40 ml Catalyst: Ni on Kieselguhr .051 2 a Base: 1N NaOH .2022 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0 71 0 0 0 4698 30 505 220 596 338 688 4642 60 71 1 193 927 299 1117 3437 90 806 189 1089 294 1350 3651 120 901 188 1236 289 1 548 2804 150 917 178 1265 270 1588 2481 180 967 167 1345 251 1687 2057 210 1131 189 1585 276 1972 2219 240 1 103 172 1 555 260 1969 1992 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0.00 2.45 0.00 0.00 0.00 118.70 30 19.77 7.60 13.32 7.51 10.22 80.62 60 27.84 6.66 20.72 6.64 16.60 67.84 90 31.56 6.53 24.35 6.53 20.06 60.89 120 35.28 6.49 27.63 6.42 23.00 54.58 150 35.90 6.15 28.28 6.00 23.60 53.94 180 37.86 5.77 30.07 5.58 25.07 51.21 210 44.28 6.53 35.43 6.13 29.30 40.14 240 43.19 5.94 34.76 5.78 29.26 41.72 Selectivity and Conversion Time Sci 1 Sci 2 Convers 0 #DlV/O! 100.00 0.00 30 1.18 54.12 32.08 60 1.18 54.10 42.84 90 1.16 53.72 48.70 120 1.16 53.70 54.02 150 1.16 53.77 54.56 180 1.17 53.90 56.86 210 1.18 54.22 66.18 240 1.16 53.74 64.85 Sel 1 = C-C / C-0 891 2 = lC-C / lC-C+C-Ol) '100 38 Experiment #108 Title: 2.4-pentanediol Hydrogenolysis with Ni on Silica/Alumina Date: 6-15-95 Reaction Conditions Temperature: 210 C Pressure: 3.5 MPa Amount Substrate: 2.4-pentanediol .4877 g Solvent: water 40 ml Catalyst: Ni on Silica/Alumina .0499 a Base: 1N NaOl-l .2086 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0 65 0 55 0 6896 30 509 290 521 413 646 4834 60 767 290 931 443 1 183 3969 90 835 232 1 121 374 1486 3466 120 960 198 1318 293 1702 3179 1 50 999 178 1406 269 1864 2965 180 1001 184 1398 285 1859 2710 210 1138 202 1591 303 2107 2458 240 1242 217 1747 319 2300 231 1 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0.00 2.24 0.00 1.22 0.00 1 17.07 30 19.93 10.01 11.65 9.18 9.60 77.50 60 30.03 10.01 20.81 9.84 17.58 59.22 90 32.69 8.01 25.06 8.31 22.08 53.80 120 37.59 6.84 29.47 6.51 25.29 48.32 150 39.12 6.15 31.43 5.98 27.70 45.05 180 39.19 6.35 31.25 6.33 27.62 44.71 210 44.56 6.98 35.57 6.73 31.31 35.48 240 48.63 7.49 39.06 7.09 34.18 28.22 Selectivity and Conversion Time Sel 1 Sol 2 Convers 0 1 .84 64.74 0.00 30 1.15 53.57 33.80 60 1.12 52.92 49.42 90 1.09 52.11 54.05 120 1.14 53.31 58.72 150 1.12 52.74 61.52 180 1.11 52.55 61.81 210 1.12 52.79 69.69 240 1.13 53.01 75.90 Sel 1 = C-C / C-O Sol 2 lC-C / lC-C + 00)) ’100 Experiment #1 09 39 Title: 2.4-pentanediol Hydrogenolysis with Raney Ni Date: 6-20-95 Reaction Conditions Temperature: 210 C Pressure: 3.5 MPa Amount Substrate: 2.4-pentanediol 0.5016 g Solvent: water 40 ml Catalyst: Raney Ni .0501 9 Base: 1N NaOH .2046 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 48 1 52 0 143 0 61 1 5 30 260 1 87 272 209 299 4988 60 400 218 476 225 523 4785 90 490 205 590 21 5 666 4557 120 622 213 743 183 819 4953 1 50 668 1 94 837 1 79 905 3889 180 840 226 1086 199 1 163 3971 210 845 180 1094 157 1150 3435 240 975 224 1311 212 1419 3209 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2,4-pd 0 1.88 5.25 0.00 3.18 0.00 120.40 30 10.18 6.46 6.08 4.64 4.44 99.95 60 15.66 7.53 10.64 5.00 7.77 90.71 90 19.19 7.08 13.19 4.78 9.90 86.00 120 24.35 7.35 16.61 4.07 12.17 80.00 150 26.16 6.70 18.71 3.98 13.45 77.19 180 32.89 7.80 24.28 4.42 17.28 66.21 210 33.09 6.22 24.46 3.49 17.09 67.94 240 38.18 7.73 29.31 4.71 21.08 56.99 Selectivity and Conversion Time Se! 1 891 2 Convers 0 1 .65 62.29 0.00 30 1.38 57.98 16.98 60 1.42 58.72 24.66 90 1.38 58.01 28.57 120 1.48 59.61 33.55 150 1.46 59.32 35.89 180 1.48 59.65 45.01 210 1.49 59.85 43.57 240 1.44 58.95 52.66 891 1 = C-C / C-O Sol 2 = lC-C / lC-C+C-O)) '100 40 Experiment #1 10 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu Date: 6-21-95 Reaction Conditions Temperature: 210 C Pressure: 3.5 MPa Amount Substrate: 2.4-pentanediol .5019 g Solvent: water 40 ml Catalyst: Raney Cu .0512 9 Base: 1N NaOH .2048 9 Integration Response Time EtOH Acetone Isormi 2-penone 2-penol 2.4-pd 0 0 46 0 0 0 8607 30 84 126 58 86 65 4503 60 155 165 126 124 132 4725 90 232 197 212 154 216 4836 120 273 195 276 150 273 4529 150 336 206 352 157 341 4548 180 364 177 389 126 347 4252 210 432 217 508 169 481 4238 240 541 232 600 185 573 4274 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0.00 1.59 0.00 0.00 0.00 120.50 30 3.29 4.35 1.30 1.91 0.97 113.15 60 6.07 5.70 2.82 2.76 1.96 108.49 90 9.08 6.80 4.74 3.42 3.21 103.56 120 10.69 6.73 6.17 3.33 4.06 101.31 150 13.16 7.11 7.87 3.49 5.07 97.87 180 14.25 6.11 8.70 2.80 5.16 98.01 210 16.91 7.49 11.36 3.76 7.15 91.71 240 21.18 8.01 13.41 4.11 8.51 86.57 Selectivity and Conversion Time Sol 1 Sel 2 Convers 0 #DIV/O! 100.00 0.00 30 1.96 66.25 6.10 60 1 .81 64.35 9.97 90 1.74 63.51 14.06 120 1.75 63.59 15.92 150 1.75 63.65 18.78 180 1.86 65.05 18.66 210 1.73 63.36 23.89 240 1.70 62.92 28.16 Sol 1 = C-C / C-O Sel 2 = lC-C / lC-C-i-C-Oll ’100 Experiment #1 18 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Base Concentration) Date: 8-9-95 Reaction Conditions Temperature: 220 C Pressure: 5 MPa 41 Amount Substrate: 2.4-pentanediol .4961 g Solvent: water 40 ml Catalyst: Raney Cu .2524 9 Base: 1N NaOH none Integration Response Time EtOH Acetone lsoprop Z-penone 2-penol 2,4-pd 0 0 34 0 90 23 30 32 51 30 162 157 2523 60 44 54 47 237 280 2650 90 63 63 71 312 447 3365 1 20 65 56 74 289 481 2809 150 78 59 90 31 1 605 2863 180 90 63 106 329 720 3104 210 105 66 127 329 834 3322 240 106 53 122 287 723 3705 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0.00 1.17 0.00 2.00 0.34 119.10 30 1.25 1.76 0.67 3.60 2.33 111.32 60 1.72 1.86 1.05 5.27 4.16 107.35 90 2.47 2.18 1.59 6.93 6.64 102.41 120 2.55 1.93 1.65 6.42 7.15 102.46 150 3.05 2.04 2.01 6.91 8.99 99.65 180 3.52 2.18 2.37 7.31 10.70 97.06 210 4.11 2.28 2.84 7.31 12.39 94.78 240 4.15 1.83 2.73 6.38 10.74 97.63 Selectivity and Conversion Time Sel 1 Sol 2 Convers 0 0.50 33.39 0.00 30 0.41 29.07 6.53 60 0.31 23.62 9.86 90 0.28 21.70 14.01 120 0.26 20.91 13.97 150 0.25 20.30 16.33 180 0.25 20.15 18.51 210 0.26 20.62 20.42 240 0.27 21.02 18.03 Sol 1 = C-C / C-0 301 2 = (C-C / (C-C-i-C-Oll ‘100 42 Experiment #119 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Base Concentration) Date: 8-9-95 Reaction Conditions Temperature: 220 C Pressure: 5 MPa Amount Substrate: 2.4—pentanediol .4961 g Solvent: water 40 ml Catalyst: Raney Cu .2518 9 Base: 1 N NaOH .5145 9 Integration Response Time EtOH Acetone lsoprop genone 2-penol 2.4-pd 0 27 56 27 66 81 4056 30 149 197 185 163 203 3529 60 262 217 360 176 335 3144 90 228 203 395 159 394 2845 120 352 223 534 177 518 3167 1 50 405 204 556 159 531 2841 180 509 229 665 179 638 2951 210 535 231 714 180 662 2454 240 573 227 737 177 672 2297 Concentrations Time EtOH Acetone Isgarop 2-penone 2-penol 2.4-pd 0 1.06 1.93 0.60 1.47 1.20 119.10 30 5.83 6.80 4.14 3.62 3.02 104.08 60 10.26 7.49 8.05 3.91 4.98 97.31 90 8.93 7.01 8.83 3.53 5.85 97.33 120 13.78 7.70 11.94 3.93 7.70 90.76 150 15.86 7.04 12.43 3.53 7.89 90.01 180 19.93 7.91 14.87 3.98 9.48 84.29 210 20.95 7.98 15.96 4.00 9.84 82.82 240 22.44 7.84 16.48 3.93 9.99 81.81 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 0.95 48.72 0.00 30 1.65 62.23 12.62 60 1.75 63.62 18.29 90 1.69 62.79 18.28 120 1.69 62.81 23.80 150 1.70 63.03 24.42 180 1.69 62.86 29.23 210 1.73 63.37 30.46 240 1.75 63.60 31.31 Sel 1 = C-C / C-O Sel 2 = (C-C / lC-C-l—C-Ol) ’100 43 Experiment #120 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Catalyst Amount) Date: 8-10-95 Reaction Conditions Temperature: 220 C Pressure: 5 MPa Amount Substrate: 2.4-pentanediol .4977 g Solvent: water 40 ml Catalyst: Raney Cu .5052 9 Base: 1N NaOH .2056 9 Integration Response Time EtOH Acetone Isogrop 2-penone 2-penol 2.4-pd 0 0 73 0 58 26 3171 30 184 225 214 243 512 3063 60 277 262 353 319 861 3289 90 297 244 397 316 946 2613 120 315 218 431 268 975 2583 150 356 235 516 326 1203 2372 180 342 198 506 290 1 167 1887 210 388 203 581 308 1327 2376 240 323 177 575 276 1281 1903 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0.00 2.52 0.00 1.29 0.39 119.40 30 7.20 7.77 4.78 5.40 7.61 96.51 60 10.85 9.05 7.89 7.09 12.79 85.63 90 11.63 8.43 8.88 7.02 14.06 83.86 120 12.33 7.53 9.64 5.96 14.49 84.21 150 13.94 8.11 11.54 7.24 17.88 77.49 180 13.39 6.84 11.31 6.44 17.34 79.85 210 15.19 7.01 12.99 6.84 19.72 75.24 240 12.65 6.11 12.85 6.13 19.03 78.43 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 1 .50 60.08 0.00 30 0.97 49.11 19.17 60 0.85 46.00 28.29 90 0.82 45.08 29.77 120 0.84 45.64 29.47 150 0.78 43.89 35.10 180 0.76 43.28 33.13 210 0.75 42.95 36.98 240 0.75 42.98 34.32 Sel 1 = C-C / C-O Sel 2 = (C-C / lC-C+C-O)) ’100 Experiment #1 21 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Catalyst Amount) Date: 8-11-95 Reaction Conditions Temperature: 220 C Pressure: 5 MPa 44 Amount Substrate: 2,4-pentanediol .5017 g Solvent: water 40 ml Catalyst: Raney Cu .0993 9 Base: 1N NaOH .2032 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0 50 0 48 31 3617 30 95 1 13 74 88 140 3728 60 133 173 132 147 244 3920 90 199 223 224 195 387 3582 120 260 237 262 212 443 3564 1 50 286 252 344 230 563 3821 180 318 226 351 202 556 2976 21 0 366 233 41 6 207 644 3402 240 377 234 435 21 3 660 2834 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4—pd 0 0.00 1.73 0.00 1.07 0.46 120.40 30 3.72 3.90 1.65 1.96 2.08 111.73 60 5.21 5.97 2.95 3.27 3.63 106.44 90 7.79 7.70 5.01 4.33 5.75 100.07 120 10.18 8.18 5.86 4.71 6.58 97.00 150 11.20 8.70 7.69 5.11 8.37 93.13 180 12.45 7.80 7.85 4.49 8.26 93.60 210 14.33 8.05 9.30 4.60 9.57 90.39 240 14.76 8.08 9.73 4.73 9.81 89.58 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 1 .13 53.06 0.00 30 1.38 57.93 7.20 60 1.29 56.43 1 1.59 90 1.26 55.76 16.89 120 1.24 55.42 19.44 150 1.22 54.88 22.65 180 1.23 55.11 22.26 210 1.22 55.04 24.92 240 1.22 55.05 25.60 Sel 1 = C-C / C-O Sel 2 = lC-C / lC-C+C-Ol) ‘100 45 Experiment #122 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Standard) Date: 8-16-95 Reaction Conditions Temperature: 220 C Pressure: 5 MPa Amount Substrate: 2.4-pentanediol 0.51 1 7 Solvent: water 40 ml Catalyst: Raney Cu .2529 9 Base: 1N NaOH .2076 g Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 32 78 28 86 52 4309 30 61 83 69 88 88 4447 60 292 164 356 193 512 3523 90 374 1 20 496 1 35 709 3064 120 291 78 422 78 696 1811 150 31 1 89 471 122 779 1527 180 484 105 714 133 1108 1406 210 667 120 940 164 1416 1467 240 679 1 1 1 999 157 1460 1719 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 1.25 2.69 0.63 1.91 0.77 122.80 30 2.39 2.87 1.54 1.96 1.31 116.14 60 11.43 5.66 7.96 4.29 7.61 98.38 90 14.64 4.14 11.09 3.00 10.53 94.33 120 11.39 2.69 9.43 1.73 10.34 98.96 150 12.18 3.07 10.53 2.71 11.58 95.62 180 18.95 3.63 15.96 2.96 16.46 84.11 210 26.12 4.14 21.01 3.64 21.04 72.48 240 26.59 3.83 22.33 3.49 21.69 71.24 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 1 .24 55.29 0.00 30 1.35 57.47 5.42 60 1.15 53.38 19.89 90 1.13 52.95 23.19 120 1.00 50.11 19.41 150 0.95 48.78 22.13 180 1.01 50.22 31.51' 210 1.02 50.48 40.98 240 1.04 50.96 41.99 Sel 1 = C-C l C-O Sel 2 = lC-C / (C-C+C-O)) '100 46 Experiment #123 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Pressure) Date: 8-18-95 Reaction Conditions Temperature: 220 C Pressure: 3 MPa Amount Substrate: 2.4-pentanediol .5372 g Solvent: water 40 ml Catalyst: Raney Cu .2500 9 Base: 1N NaOH .2126 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 73 144 62 146 111 5107 30 331 335 289 465 440 2771 60 403 389 381 610 609 1 839 90 453 392 455 672 739 1034 120 468 347 498 637 81 1 745 1 50 505 366 566 726 970 592 180 684 486 775 1034 1350 749 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 2.86 4.97 1.39 3.24 1.65 128.95 30 12.96 11.57 6.46 10.33 6.54 96.58 60 15.78 13.43 8.52 13.56 9.05 87.48 90 17.74 13.54 10.17 14.93 10.98 82.31 120 18.32 11.98 11.13 14.16 12.05 82.02 150 19.77 12.64 12.65 16.13 14.41 75.87 180 26.78 16.78 17.33 22.98 20.06 55.47 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 1 .30 56.51 0.00 30 1.07 51.66 25.10 60 0.97 49.27 32.16 90 0.91 47.78 36.17 120 0.88 46.87 36.39 150 0.83 45.29 41.16 180 0.79 44.21 56.98 Sel 1 = C-C / C-O Sol 2 = lC-C / lC-C+C-O)l '100 47 Experiment #124 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Temperature) Date: 8-21-95 Reaction Conditions Temperature: 240 C Pressure: 5 MPa Amount Substrate: 2.4-pentanediol .4934 g Solvent: water 40 ml Catalyst: Raney Cu .2507 9 Base: 1N NaOH .2038 9 Integration Response Time EtDH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 62 126 52 132 102 4870 30 437 333 467 382 703 2407 60 669 363 764 455 1037 2283 90 741 335 911 444 1221 1301 120 726 299 928 426 1256 606 150 901 311 1177 461 1574 681 1 80 962 350 1270 547 1 662 572 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 . 2.43 4.35 1.16 2.93 1.52 118.40 30 17.11 11.50 10.44 8.49 10.45 79.94 60 26.19 12.53 17.08 10.11 15.41 64.98 90 29.01 11.57 20.37 9.87 18.14 59.92 120 28.43 10.32 20.75 9.47 18.66 60.52 150 35.28 10.74 26.31 10.24 23.39 48.60 180 37.67 12.09 28.39 12.16 24.70 42.48 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 1 .24 55.34 0.00 30 1.16 53.68 32.48 60 1.16 53.71 45.12 90 1.14 53.27 49.39 120 1.10 52.48 48.88 150 1.10 52.42 58.95 180 1.10 52.35 64.12 Sel 1 = C-C/ C-O Sel 2 = lC-C / lC-C+C-O)) '100 48 Experiment #125 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Temperature) Date: 8-22-95 Reaction Conditions Temperature: 200 C Pressure: 5 MPa Amount Substrate: 2.4-pentanediol .4991 g Solvent: water 40 ml Catalyst: Raney Cu .2506 a Base: 1 N NaOH .2090 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penol 2,4-pd 0 0 49 0 49 73 4445 30 93 95 1 24 89 21 8 3880 60 162 103 242 104 371 3722 90 1 95 87 307 95 468 3330 1 20 284 94 440 101 694 3335 1 50 280 69 420 68 546 3218 1 80 354 77 559 84 806 3080 210 384 77 605 88 888 2797 240 393 71 625 83 916 2641 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2,4-pd 0 0.00 1.69 0.00 1.09 1.08 119.80 30 3.64 3.28 2.77 1.98 3.24 109.74 60 6.34 3.56 5.41 2.31 5.51 104.32 90 7.64 3.00 6.86 2.11 6.95 101.98 120 11.12 3.25 9.84 2.24 10.31 95.14 150 10.96 2.38 9.39 1.51 8.11 98.81 180 13.86 2.66 12.50 1.87 11.98 91.45 210 15.04 2.66 13.53 1.96 13.19 89.04 240 15.39 2.45 13.97 1.84 13.61 88.44 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 0.78 43.77 0.00 30 1.16 53.71 8.40 60 1.15 53.40 12.92 90 1.09 52.12 14.87 120 1.04 51.03 20.58 150 1.22 55.02 17.52 180 1.09 52.26 23.67 210 1.07 51.65 25.68 240 1.06 51.52 26.18 Sel 1 = C-C / C-O Sel 2 = lC-C / lC-C+C-Oll “100 Experiment #126 Title: 2.4-pentanediol Hydrogenolysis with Raney Cu (Pressure) Date: 8-23-95 Reaction Conditions Temperature: 220 C Pressure: 7 MPa 49 Sel 1 = C-C / C-O Sel 2 = (C-C / (C-C+C-O)) “100 Amount Substrate: 2.4-pentanediol .5031 g Solvent: water 40 mi Catalyst: Raney Cu .2515 9 Base: 1N NaOH .2005 9 Integration Response Time EtOH Acetone lsoprop 2-penone 2-penoi 2.4-pd 0 0 63 0 62 20 3861 30 103 137 116 119 194 4305 60 158 138 205 123 326 4123 90 197 125 279 1 17 437 3696 120 207 107 302 98 451 3514 150 251 116 386 110 561 3491 180 285 110 427 101 604 3391 210 326 1 12 481 102 672 3403 240 387 1 17 593 1 10 862 3437 Concentrations Time EtOH Acetone lsoprop 2-penone 2-penol 2.4-pd 0 0.00 2.18 0.00 1.38 0.30 120.80 30 4.03 4.73 2.59 2.64 2.88 109.59 60 6.19 4.77 4.58 2.73 4.84 105.46 90 7.71 4.32 6.24 2.60 6.49 102.57 120 8.10 3.69 6.75 2.18 6.70 102.65 150 9.83 4.01 8.63 2.44 8.34 98.79 180 11.16 3.80 9.55 2.24 8.97 97.33 210 12.76 3.87 10.75 2.27 9.99 94.86 240 15.15 4.04 13.26 2.44 12.81 89.32 Selectivity and Conversion Time Sel 1 Sel 2 Convers 0 1 .30 56.50 0.00 30 1.33 56.99 9.28 60 1.23 55.23 12.70 90 1.16 53.72 15.09 120 1.18 54.05 15.03 150 1.17 53.96 18.22 180 1.19 54.33 19.43 210 1.19 54.41 21.48 240 1 .13 53.14 26.06 50 Ethanol Calibration Concentration (mM) GC Response 288 7606 230 5705 179 4518 122 2973 51 1 169 Response 8000 7000 6000 5000 4000 3000 2000 1 000 Ethanol Calibration l l I I I I 0 50 100 1 50 200 250 Concentration (mM) ~41— —0— 300 Ethanol concentration = Ethanol response / 25.54 Concentration (mM) 84.6 42.3 21.2 10.6 5.3 51 Acetone Calibration GC Response 2512 1 103 616 284 173 Response 3000 a" 2500 - 2000 - 1500 3 1000 r 500 - Acetone Calibration l l I I 40 60 80 Concentration (mM) «>- Acetone concentration = Acetone response / 28.96 Concentration (mM) 52 isopropanol Calibration GC Response Concentration (mM) 50.4 1724 25.2 910 12.6 468 6.3 236 lsopropanol Calibration 1800 - 1600 -~ 1400 ~~ 1200 .. 3 1000 S Q g 800 -~ 600 ~- 400 -~ 200 —~ 0 1 : i 1 i .1 0 10 20 30 40 50 60 lsopropanol concentration = lsopropanol response / 25.54 53 2-pentanone Calibration Concentration (mM) GC Response 86.3 3997 43.2 1710 21.6 1015 10.8 414 5.4 281 2-pentanone Calibration 4000 " D 3500 v 3000 v 2500 v 2000 v 1500 + 1000 v 500 4r O i + i i i 0 20 40 60 80 1 00 Concentration (mM) 2-pentanone concentration = 2-pentanone response / 45.00 54 2-pentanol Calibration Concentration (mM) GC Response 89.6 6073 44.8 2935 22.4 1490 1 1.2 753 5.6 387 Response 7000 6000 5000 4000 3000 2000 1 000 2-pentanol Calibration J I unh— L I ‘— 0 20 40 60 80 1 00 Concentration (mM) 2-pentanol concentration = 2-pentanol response I 67.29 Timelmin) 0 30 60 90 120 1 50 180 210 240 Timelmin) 0 30 60 90 1 20 1 50 1 80 210 240 Conversion T=200 T=220 T=240C 0 8.4 12.92 14.87 20.58 17.52 23.67 25.68 26.18 In (1—x) T = 200 0 -0.08774 -0.13834 -0.16099 -0.23042 -0.19261 -0.2701 -0.29679 -0.30354 55 Effect of Temperature 0 5.42 19.89 23.19 19.41 22.13 31.51 40.98 41.99 T=220 0 -0.05572 -0.22177 -0.26384 -0.2158 -0.25013 -0.37848 -0.52729 -0.54455 0 32.48 45.12 49.39 48.88 58.95 64.12 T=240C 0 -0.39275 -0.60002 -0.68102 -0.67099 -0.89038 -1 .02499 0 0 _. II T = 200 c ’5 : D r = 220 c s o r = 240 c 42 . 1 4. . . o 50 100 150 200 250 Time (min) T=200 c T=220 c r=240 c k l1/min) 0.00103 0.0021 1 0.00383 kl1/hr) 0.0618 0.1266 0.2298 56 Arrhenius Plot Temp(K) k (1 /hr) 1/T In k 473 0.062 0.0021 14 -2.78062 493 0.127 0.002028 -2.06357 513 0.23 0.001949 -1.46968 Arrhenius Plot to Determine Activation Energy 4L 1 I TlKI I fl 0.0019 0.00195 0.002 0.00205 0.0021 0.00215 y-int 14.05556 slope -7958.22 Activation Energy = 66.16468 kJ / mol Time (min) 0 30 60 90 1 20 1 50 1 80 210 240 Time (min) 0 30 60 90 120 1 50 1 80 210 240 P=3 MPa 0 25.1 32.16 36.17 36.39 41.16 56.98 ln(1-x) P=3 MPa 0 -0.28902 -0.38802 -0.44895 -0.4524 -0.53035 -0.84351 0 0 57 Effect of Pressure P=5MPa 0 5.42 19.89 23.19 19.41 22.13 31.51 40.98 41.99 P: 5MPa 0 -0.05572 -0.22177 -0.26384 -0.2158 -0.25013 -0.37848 -0.52729 -0.54455 P=7MPa 0 9.28 12.7 15.09 15.03 18.22 19.43 21.48 26.06 P= 7MPa 0 -0.09739 -0.13582 -0.16358 -0.16287 —0.201 14 -0.21604 -0.24182 -0.30192 Effect of Pressure on Rate Constant I P=3 MPa 55‘ D P=5MPa E a P=7MPa 0 100 200 300 Timelmini P=3 MPa P=5 MPa P=7 MPa k (1/min) 0.00305 0.0021 1 0.00086 k l1/hr) 0.183 0.1266 0.0516 58 Determination of Order of Pressure Pressure (MPa) k (1 lhr) 3 0.183 5 0.127 7 0.052 In P In R 1.098612289 -1.69827 1.609437912 ~2.06357 1 .945910149 -2.95651 In Ka 1.2 1.4 1.6 InP 1.8 intercept slope -0.03314 -1 .42222 59 Effect of Catalyst Type Conversion Timelmin) Ni on K Ni on S Raney Ni Raney Cu 0 0 0 0 0 30 32.08 33.8 16.98 6.1 60 42.84 49.42 24.66 9.97 90 48.7 54.05 28.57 14.06 120 54.02 58.72 33.55 15.92 150 54.56 61.52 35.89 18.78 180 56.86 61.81 45.01 18.66 210 66.18 69.69 43.57 23.89 240 64.85 75.9 52.66 28.16 In(1-x) Timelmin) Ni on K Ni on S Raney Ni Raney Cu 0 0 0 0 0 30 -0.38684 -0.41249 -0.18609 -0.06294 60 -0.55932 -0.68161 -0.28316 -0.10503 90 -0.66748 -0.77762 -0.33645 -0.15152 120 -O.77696 -0.88479 -0.40872 -0.1734 150 -0.78878 -0.95503 -0.44457 -0.20801 180 -0.84072 -0.9626 -0.59802 -0.20653 210 -1 .08412 -1 .19369 -0.57217 -0.27299 240 -1 .04555 -1 .42296 -0.74781 -0.33073 I Ni on K 55‘ 0 Ni on s 2 9 Raney Ni 0 Raney Cu Effect of Catalyst on Rate Constant -1 _6 c : : ¢ : 0 50 100 1 50 200 250 Time (min) Ni on K Ni on S Raney Ni Raney Cu k (1/min) 0.00308 0.00407 0.00246 0.00116 k (1/hr) 0.1848 0.2442 0.1476 0.0696 LIST OF REFERENCES 60 LIST OF REFERENCES Andrews, M.A.; Klaeren, S.A. Selective Hydrocracking of Monosaccharide Carbon- Carbon Single Bonds under Mild Conditions. Ruthenium Hydride Catalyzed Formation of Glycols. J.Am.Chem.Soc. 1989, 111, 4131-4133 Chang, F.W.; Kuo, K.T.; Lee, ON. A Kinetic Study on the Hydrogenolysis of Sorbitol over Raney Ni Catalysts. J.ChinJ. Ch.E. 1985, 16, 17-23 Clark I.T. Hydrogenolysis of Sorbitol. IndEng. Chem. 1958, 50, 1125-1126 Connor R.; Adkins H. Hydrogenolysis of Oxygenated Organic Compounds. J.Am.Chem.Soc. 1932, 54, 4678-4690. Cook J .; Mailis PM. Formaldehyde as a Hydrogen-donor to Aldehydes and Ketones in Metal-catalyzed Reactions in Water. J.Chem.Soc., Chem Comun. 1981, 924-925 Lowenheim,F.A.; Moran,M.K. Industrial Chemicals, 4th Edition, John Weily and Sons, New York, 1985 Montassier C.; Giraud D.; Barbier J. Polyol Conversion by Liquid Phase Heterogenous Cataysis over Metals. In Heterogenous Catalysis and Fine Chemicals; Guisnet M. et al. Ed; Elsevier: Amsterdam, 1988 Neilsen A.T.; Houlihan W.J. The Aldo] Condensation. In Organic Reactions, vol. 6; Adams R. et al. Ed.;Weiley: New York, 1968. Sohounloue, D.K.; Montassier, C.; Barbier, J. Catalytic Hydrogenolysis of Sorbitol. React.Kinet.CataI.Lett. 1983, 391-397 Van Ling, G.; Driessen, AJ.; Piet A.C.; Vlugter, J .C. Continuous Production of Glycerol by Catalytic High Pressure Hydrogenolysis of Sucrose. IndEng.Chem.ProdRes.Develop. 1970, 9, 210-212 Van Ling, G.; Ruijterman, G.; Vlugter, J .C. Catalytic Hydrogenolysis of Saccharides I. Qualitative and Quantitative Methods for the Identification and Determination of the Reaction Products. CarbohydRes. 1967, 4, 380-3 86 nICHrceN STATE UNIV. LIBRARIES ll11111111HI1111111111111111111111 31293014102457