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Kinetics, Catalysis, and Reaction Engineering
Cation-exchange Resin Catalyzed Ketalization Reaction of Cyclohexanone with 1,4-butanediol: Thermodynamics and Kinetics Jia Qian, MinQian Qiu, Zuoxiang Zeng, Weilan Xue, and Jumei Xu Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.8b00354 • Publication Date (Web): 21 Mar 2018 Downloaded from http://pubs.acs.org on March 21, 2018
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Cation-exchange
Resin
Catalyzed
Ketalization
Reaction
of
Cyclohexanone with 1,4-butanediol: Thermodynamics and Kinetics Jia Qian, MinQian Qiu, Zuoxiang Zeng, Weilan Xue*, and Jumei Xu Institute of Chemical Engineering, East China University of Science and Technology, 200237 Shanghai, China
E-mail:
[email protected] ABSTRACT: The thermodynamics and kinetics for the ketalization reaction of cyclohexanone with 1,4-butanediol catalyzed by 732 cation-exchange resin were studied for the first time. The reaction equilibrium compositions were obtained from 293.15 K to 333.15 K at atmospheric pressure, and the equilibrium constants was estimated using the UNIFAC model. The thermodynamic properties of the ketalization reaction were evaluated: ∆H0 = -12.85 kJ·mol-1, ∆G0 = -1.04 kJ·mol-1, ∆S0 = -39.61 J·K-1·mol-1. The influences of various experimental parameters like agitation speed, initial molar ratio of reactants, temperature, catalyst loading and particle size on the conversion of limiting reactant were studied. Different kinetic models were tested against the experimentally measured kinetic data and the results show that the Eley-Rideal model with chemisorption of 1,4-butanediol on the active sites predict the kinetics best. The Ea value for the overall ketalization reaction is found to be 43.89 kJ·mol-1. Keywords: ketalization, cyclohexanone, 1,4-butanediol, cation-exchange resin catalyst, kinetics
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1.
Introduction Ketals have been widely applied in food, tobacco, flavors, fragrances, cosmetics, and
pharmaceutical industries as raw materials or intermediates or target productions due to their distinctive fragrance.1,2 Ketals can also be used as oxygenated additives in order to improve the performances of fuels.3 Additionally, ketalization reaction of carbonyl compounds with diols to form cyclic ketals is a common method to protect both carbonyls and diols in organic synthesis.4 Particularly, the ketal 7,12-dioxaspiro[5.6]dodecane is useful in perfumery compositions of skin care cosmetics or personal care formulas, e.g. creams, lotions, perfumes, shampoos, conditioners, soaps, cleansers and detergents.5,6 Ketals are typically synthesized from alcohols and carbonyl compounds. Conventionally, the catalysts of ketalization reaction are strong liquid protonic acids like HCl, H2SO4, HF, H3PO4 and p-toluenesulphonic acid, etc. But these catalysts cause the problems of environmental pollution and equipment corrosion, and cause an increase in the difficulty and complexity to separate and purify the products.7 Therefore, from the points of environmental and economic benefits, scientists have developed many kinds of eco-friendly and efficient heterogeneous solid acid catalysts, such as acidic ion-exchange resins (Amberlyst-47, Indion-130, Amberlyst-15, Ambertlyst-36, Dowex 50Wx2, Dowex 50Wx8, etc.),8-10 zeolites,11,12 Montmorrilonite,12,13 silica supported acids,14 and promoted metal oxides.15 They are used in acid catalyzed reactions including ketalization. In the synthesis of cyclic ketals or acetals through the reaction of ketones or aldehydes with polyalcohols, literature is found in the lack of detailed studies on the thermodynamics and kinetics for the ketalization of cyclohexanone with 1,4-butanediol. The ketalization reaction scheme of cyclohexanone and 1,4-butanediol is given in Scheme 1, where A, B, C, and D, represent cyclohexanone, 1,4-butanediol, 7,12-dioxaspiro[5.6]dodecane and water, respectively. Compared to the more stable five-member-ring or six-member-ring ketals, which are reported more frequently, seven-member-ring ketals have better performance in fragrance due to their particular structure, and are more difficult to be synthesized.16 The synthesis of this kind of ketal not only expands the family of perfumes, but also provides a new method for the synthesis of seven-member-ring organic compounds. Sulphonated strong cation-exchange resin (732-CR) used in this work has the same structure and components ACS Paragon Plus Environment
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with Amberlite IR 120.17 It can be used in separation and purification fields such as the treatment of wastewater containing heavy metal ions18,19 and water softening20 due to its ion exchange property. It can also be used in ketalization reactions as a solid acid catalyst with its acidity.21 In this work, the ketalization between cyclohexanone and 1,4-butanediol catalyzed by 732-CR has been studied in a batch experimental set-up at laboratory scale to obtain thermodynamic and kinetic data for the further industrialized production of this ketal. Thermodynamic equilibrium constant and parameters were estimated. The effects of agitation speed, catalyst particle size, initial molar ratio of reactants, temperature, and catalyst loading were discussed. The experimental kinetic data were treated with several kinetic models. A rate equation with kinetic parameters based on the Eley-Rideal mechanism for the overall reaction was obtained.
2. 2.1.
Experiments Materials The reactants used this study were cyclohexanone (99.5 wt%, Shanghai Lingfeng
Chemical Reagent Co., Ltd.) and 1,4-butanediol (99 wt%, Sinopharm Chemical Reagent Co., Ltd.). The ketal 7,12-dioxaspiro[5.6]dodecane (96 wt%) was purchased from BST Tianjin Co., Ltd.(Tianjin, China). 732-CR in sodium form was supplied by Shanghai Resin Company (Shanghai, China). The sodium form resin was treated with 1 mol·L-1 HCl for 24 h in order to convert into hydrogen form resin, a solid acid catalyst. Then it was dried and sieved into different particle diameters. The physicochemical properties of the catalyst were presented in Table 1. 2.2.
Apparatus Batch ketalization between cyclohexanone and 1,4-butanediol was performed in a 100
mL three-necked glass reactor at atmospheric pressure. The reactor was equipped with a reflux condenser and a mechanical stirrer, and was kept in a water bath (HH-2) with a accuracy of ±0.1 K, as is demonstrated in Figure 1. The reactants and catalyst were added and samples were withdrawn through the sampling port. Surface area of catalyst was determined by N2 isotherm adsorption of Brunauer-Emmett-Teller method (NOVA 4200e Surface Area & ACS Paragon Plus Environment
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Pore Size apparatus). The amount of acid sites on the catalyst was measured by titration with NaOH aqueous solution. 2.3.
Equilibrium runs The amount of reactants added into the batch reactor were 0.24 mol of cyclohexanone
and 0.2 mol of 1,4-butanediol, the weight of dry catalyst is 1.0 % w/w based on the mass of the total reactants, and the temperatures were settled at 293.15, 303.15, 318.15, and 333.15 K, respectively. The initial time for a run is taken as the moment the catalyst was added. Samples were withdrawn from sampling port for GC analysis 3, 6, 9, and 12 h after the beginning of the reaction till the equilibrium was reached (the composition of the reaction system did not change present in 0.2 mL samples). The GC analysis procedure is given in Supporting Information 1. 2.4.
Kinetic runs The kinetic runs were conducted as the same procedure as equilibrium runs. Known
amounts of cyclohexanone and 1,4-butanediol were added into the reactor. The temperature of water bath was maintained at 293.15, 303.15, and 318.15 K, respectively. At desired time intervals (3, 6, 10, 20, 35, 50…300, 360…720 min), sample was withdrawn and analyzed by GC.
3. 3.1.
Results and Discussion Thermodynamic results Thermodynamic experiments were conducted in at batch model with fixed initial molar
ratio of cyclohexanone to 1, 4-butanediol (rA/B = 1.2) and catalyst loading (1 % w/w) at the temperature of 293.15, 303.15, 318.15, and 333.15 K, respectively. All the experiments were lasted 12 h in order to insure the reaction reach equilibrium. At the operating conditions of the experiments conducted in this study, the selectivity to the ketal was considered 100%.22 Considering the non-ideal behavior of the reaction system in liquid phase, the activity (ai) of the component i (i = A, B, C, and D) was used to substitute for the molar fraction at equilibrium (xi). Therefore, the thermodynamic equilibrium constant (Ke) for the ketalization reaction is given as following:
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Ke =
aC aD xC x D γ Cγ D = = K x ⋅ Kγ aA aB x A x B γ Aγ B
(1)
where γi is the activity coefficients, which were computed by the UNIFAC group contribution method.23,24 The splitting of the groups and their corresponding volume and area parameters25 are listed in Table S1. Table 2 shows the equilibrium composition at various temperatures and the equilibrium constants containing activity coefficients. Table 2 shows that the equilibrium constant decreases with the raise in reaction temperature, indicating the ketalization reaction is exothermic. The dependency of Ke on temperature could be measured by plotting ln Ke vs. 1/T (Figure 2).
ln K e =
∆S 0 ∆H 0 1 − R R T
(2)
where ∆H0 is the standard enthalpy (kJ·mol-1), and ∆S0 is the standard entropy (J·mol-1·K-1) at 298.15 K. The linear correlation of experimental data in the temperature range of the experiments in this study gives:
1545.7 (3) − 4.7634 T Therefore, it is obtained ∆H0 = -12.85 kJ·mol-1 and ∆S0 = -39.61 J·mol-1·K-1. Then the ln K e =
standard free energy change (∆G0) for the system can be calculated from the equation:
∆G = ∆H 0 − T∆S 0
(4)
leading to ∆G0 = -1.04 kJ·mol-1, suggesting the ketalization reaction is spontaneous at standard state. More detailed study of thermodynamics is given in Supporting Information 2. 3.2.
Kinetic results To investigate the catalytic performance of the strong acidic 732 cation exchange resin in
the ketalization of cyclohexanone to 1, 4-butanediol and obtain the optimum operating conditions of the reaction, the effects of various operation conditions were evaluated as follows. 3.2.1.
Effect of agitation speed
A wide range of agitation speeds (150 rpm-900 rpm) was tested at temperature of 318.15 K, initial molar ratio of cyclohexanone to 1, 4-butanediol (rA/B) of 1.2 and catalyst loading of 1.0 % w/w. Figure 3 shows the conversion of 1, 4-butanediol (XB) at different agitation speeds.
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It is observed that the agitation speed has no appreciable effect on XB above 300 rpm, indicating the elimination of external mass transfer resistance when exceeding this speed. All further experiments were performed at the agitation speed of 800 rpm thus the homogeneous mixtures of the reaction system were achieved with vigorous stirring. Interestingly, many other researchers also conducted their researches at agitation speeds of 600 to 1000 rpm since they found there is no external mass transfer limitation at these speeds.2,26,27 3.2.2.
Effect of particle size
To investigate the limitation of internal mass transfer in catalyst particles, the dry catalyst was divided into four classes with mean diameters of 315, 365, 640 and 1045μm according to particle size using sample sifters. The equilibrium conversions of 1, 4-butanediol with different catalyst particle size were listed in Table 3. It shows that at the same experiment conditions (318.15 K, rA/B=1.2 and catalyst loading of 1.0 % w/w), the equilibrium conversions are almost the same, indicating there is no internal mass transfer resistance for all cases. Hence, the catalyst particle size used in the remaining experiments was 365μm. 3.2.3.
Effect of temperature
The influence of temperature on the ketalization of cyclohexanone and 1, 4-butanediol was studied at temperatures of 293.15, 303.15, and 318.15 K, rA/B=1.2, and 1.0 % w/w catalyst loading. As shown in Figure 4, it is clear that a higher temperature leads to a faster initial rate of the ketalization and a shorter time requirement for reaching the equilibrium. This may be due to the acceleration of the thermal motion of reactants molecules at a higher temperature. It can also be observed in Figure 4 that as the temperature increases, the equilibrium conversation of 1,4-butanediol decreases, although the reduction is small. This phenomenon indicates the exothermic nature of the ketalization reaction and the enthalpy of this reaction is relatively small, as evidenced previously by the thermodynamics results. 3.2.4.
Effect of initial molar ratio of reactants
The influence of feed ratio of cyclohexanone (A) to 1, 4-butanediol (B) was studied varying the value of rA/B from 0.5 to 3 at the other conditions of 318.15 K and 1.0 % w/w catalyst loading. This including all possible situations: rA/B = 1:1 represents the stoichiometric ratio, rA/B = 1:2 represents the excess of 1, 4-butanediol, and rA/B = 2:1 or 3:1 represents the excess of cyclohexanone. Figure 5 shows the influence of rA/B on the conversion of limiting ACS Paragon Plus Environment
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reactant with time evolution. It reveals that the limiting reactant conversion increases with the increasing amount of excess reactants. For example, at reaction time of 50 min, the conversion of 1, 4-butanediol increased from 43.6% to 57.6% when rA/B increased from 1:1 to 3:1, and the conversion of cyclohexanone increased from 43.6% to 46.2% when rA/B changed from 1:1 to 1:2. Therefore, the increase in the amount of either reactant cyclohexanone or 1, 4-butanediol can make the reaction shift towards the products formation. In addition, by comparing rA/B of 2:1 and 1:2, we can find that an excess of cyclohexanone leads to a more significant raise of limiting reactant conversion than an excess of 1, 4-butanediol. This implies that increasing the amount of cyclohexanone rather than1, 4-butanediol is more beneficial, efficiency and preferable. In conclusion, the value of rA/B = 1.2 was used in most of the ketalization experiments considering the cost of raw materials and reaction conservation. 3.2.5.
Effect of catalyst loading
In the experimental conditions of 318.15 K and rA/B=1.2, the catalyst loading of 0.5 %, 1.0 %, and 2.0 % w/w based on the mass of total reactants was set to study the influence of catalyst loading on the conversion of 1, 4-butanediol (XB), as shown in Figure 6. In principle, the more acid sites, the higher acidity. So it can be observed in Figure 6 that the reaction rates accelerate as the catalyst dose increases. This is caused by the increase in the amount of acidic sites on the solid catalyst available in the reaction system, resulting in a higher conversion of 1, 4-butanediol. In addition, change the amount of catalyst does not change the equilibrium composition due to the chemical reaction equilibrium limitation, and it just change the time needed to achieve reaction equilibrium. Moreover, it is found that the improvement in XB is more obvious as the catalyst loading increases from 0.5 % to 1.0 % w/w than that from 1.0 % to 2.0 % w/w, indicating that beyond a certain value, further rise in catalyst loading is not very necessary for the conversion. More detailed discussion of catalyst activity using TOF is presented in Supporting Information 3. Therefore, 1.0 % w/w is chosen as the optimum loading and used in further experiments. 3.3.
Kinetic modeling The kinetic studies in this study were conducted under the temperatures of 293.15,
303.15, and 318.15 K. The results of kinetic experiments of the ketalization of cyclohexanone and 1, 4-butanediol, XB versus t, are shown in Figure 4. ACS Paragon Plus Environment
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Once the reactants diffuse into the pore space of the catalyst particles, various kinetic mechanisms can be applied to describe the adsorption, surface reaction and desorption processes. The kinetic models of Pseudo-homogeneous (PH) model, Eley–Rideal (ER) model with the adsorption of reactant A or B, and Langmuir–Hinshelwood–Hougen–Watson (LHHW) model were used to test against the experimental kinetic data. The methodology is similar to ref. 28 and 29. Consequently, ER model with the chemisorption of the limiting reactant 1, 4-butanediol, and then reacts with cyclohexanone from the bulk liquid phase at the surface of 732-CR catalyst was found to be the most appropriate mechanism for this kind of ketalization reaction. ER model between adsorbed B and nonadsorbed A can be described as the following steps. (The detailed description of reaction mechanism using PH model, ER model between adsorbed A and nonadsorbed B, and LHHW model were present in Supporting Information 4.) (1) Adsorption of 1, 4-butanediol:
(2) Surface reaction between the adsorbed 1, 4-butanediol and liquid phase cyclohexanone to yield adsorbed hemi-ketal (I1S):
(3) Surface reaction of hemi-ketal to form an intermediate product (I2) and simultaneously undergo dehydration to give adsorbed water (DS). This step is considered as the rate-controlling step:
(4) Reaction of I2 with anther molecular of –OH to generate ketal:
(5) Desorption of water:
Therefore, the reaction rate (r, mol·g-1·min-1) of ER model between adsorbed 1, 4-butanediol and nonadsorbed cyclohexanone is expressed by the following equation:
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r=
k1 (aA aB − aC aD / K e ) 1+ K B aB + K D aD
(5)
where k1 is forward reaction rate constant referring to the catalyst mass (mol·g-1·min-1). Ke, KB and KD represent the reaction equilibrium constant and the adsorption equilibrium constants for 1,4-butanediol and water, respectively. In rate expression, activity rather than concentration is used for the purpose of improving the prediction accuracy of the model fitted against the measured kinetic data. At a constant temperature, according to the mass balance of ketalization in a batch reactor, the reaction rate of component i can be written as
ri =
dxi mcat υi dt n0
(6)
where n0 is the total mole numbers of reactants in reaction system (mol), mcat is the catalyst mass (g), t is reaction time (min), and υi is the stoichiometric coefficient of component i. The calculated reaction rate (rcal) is expressed in eq 5 and the experimental measured rate (rexp) is given in eq 6. Taking the limiting reactant B into calculation and combining the eq 5 with eq 6, we can obtain:
n0
dx B = r(α A , α B , αC , α D ,T ) mcat υ B dt
(7)
The theoretical reaction rates obtained from different kinetic models were regressed with the reaction rates measured by kinetic experiments at different temperatures. The kinetic model parameters were determined by minimizing the value of the sum of residual squares (SRS) as follows:
SRS = ∑ (rexp − rcal )
2
(8)
N
The values of kinetic modeling parameters k1, KB and KD are listed in Table 4. The parity plot of the calculated reaction rate against the experimental reaction rate is presented in Figure 7. It shows that the calculated values lie close to the measured results, indicating that the ER model with the adsorption of component 1,4-butanediol (eq 5) predicts the kinetic data of the cation-exchange resin catalyzed ketalization system well.
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The relevance of the kinetic modeling parameters k1, KB and KD on temperature are described by the Arrhenius equations:
k1 = k0,1 exp(−
Ea ) RT
Ki = K 0,i exp(−
∆H i ) RT
(9)
(10)
where Ea is the activation energy of ketalization reaction between cyclohexanone and 1,4-butanediol. ∆Hi is the enthalpy for the adsorption of component i. k1,0 and Ki,0 are pre-exponential factors. The linear regressions of the Arrhenius equations are drawn in Figure 8. From the plot, Ea = 43.89 kJ·mol−1. Thus, the kinetic rate equation and the parameters of the ketalization reaction of cyclohexanone and 1, 4-butanediol using 732-CR as catalyst are presented in Table 5.
4. Conclusion The ketalization reaction between cyclohexanone and 1,4-butanediol using 732 cation-exchange resin as catalyst was studied. The thermodynamic equilibrium constant at temperatures range of 293.15–333.15 K was investigated using the UNIFAC model, and given as Ke = 0.008537exp(1545.7/T). The thermodynamic properties of the ketalization reaction were evaluated and the results gives: ∆H0 = -12.85 kJ·mol-1, ∆S0 = -39.61 J·K-1·mol-1, ∆G0 = -1.04 kJ·mol-1, indicating the exothermic nature of the reaction. In batch study of the heterogeneous reaction, the resistance of external mass transfer can be eliminated when agitation speed ≥ 300 rpm and internal diffusion limitations were found to be absent. The increase in temperature and catalyst loading before reaction equilibrium can lead to the increase in conservation of 1, 4-butanediol. And it was found to be more beneficial and efficiency to improve the conservation of limited reactant by an initial excess of cyclohexanone rather than1, 4-butanediol. The regression of calculated and experimental values of reaction rates demonstrates the Eley−Rideal model assuming the chemisorption of limited reactant 1, 4-butanediol can successfully interpret the experimental kinetic data. The thermodynamic and kinetic information obtained in this study could provide an optimal setup and a theoretical basis for the ketalization process. The Ea value for the overall ketalization ACS Paragon Plus Environment
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reaction is found to be 43.89 kJ·mol-1.
Abbreviation A = cyclohexanone B = 1, 4-butanediol C = 7,12-dioxaspiro[5.6]dodecane D = water Ea = activation energy, kJ·mol-1 i = component i k1 = forward reaction rate constant, mol·g-1·min-1 Ke = equilibrium constant Ki = adsorption equilibrium constants for component i Ki,0 = pre-exponential factor mcat = weight of catalyst, g n0 = total number of moles in reaction system, mol rA/B = initial mole ratio of reactants A and B r = reaction rate, mol·g-1·min-1 -1
rcal = calculated reaction rate, mol·g ·min
-1
-1
rexp = experimental reaction rate, mol·g ·min
-1
rpm = revolutions per minute t = time, min T = absolute temperature, K x = molar fraction of the component X = conservation of reactant ∆G0 = standard Gibbs free energy, kJ·mol-1 ∆H0 = standard enthalpy, kJ·mol-1 ∆S0 = standard entropy, J·mol-1·K-1 ∆Hi = enthalpy of the adsorption reaction of component i Greek Letters a = activity ACS Paragon Plus Environment
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γ = activity coefficient υ = stoichiometric coefficient
Supporting Information Table S1. UNIFAC group identification of the components in ketalization system Supporting Information 1. GC analysis procedure Supporting Information 2. more details of the thermodynamic study of ketalization reaction Supporting Information 3. discussion of catalyst activity using TOF Supporting Information 4. ketalization mechanism using PH model, ERA model, and LHHW model and the comparison of the fitting results of these models
References (1) Tao, D. J.; Li, Z. M.; Cheng, Z.; Hu, N.; Chen, X. S. Kinetics study of the ketalization reaction of cyclohexanone with glycol using Brønsted acidic ionic liquids as catalysts. Ind. Eng. Chem. Res. 2012, 51, 16263–16269. (2) Graca, N. S.; Pais, L. S.; Silva, V. M. T. M.; Rodrigues, A. E. Oxygenated biofuels from butanol for diesel blends: synthesis of the acetal 1,1-dibutoxyethane catalyzed by amberlyst-15 ion-exchange resin. Ind. Eng. Chem. Res. 2010, 49, 6763–6771. (3) Esposito, R.; Cucciolito, M. E.; D'Amora, A.; Guida, R. D.; Montagnaro, F.; Ruffo, F. Highly efficient iron(III) molecular catalysts for solketal production. Fuel Process. Technol. 2017, 167, 670–673. (4) Moraes, L. A. B.; Meurer, E. C.; Eberlin, M. N. On the solvent and counter ion-free mechanism of ketalization reactions of gaseous activated carbonyls. Int. J. Mass Spectrom. 2017, 421, 170–177. (5) Webb, D.; Wagner, R. Perfumery compositions containing 7,12-dioxaspiro[5,6]dodecane. GB 2157564 A. 1985. (6) Suffis, R.; Barr, M. L.; Ishida, K. Cosmetic compositions containing body activated fragrance for contacting the skin. US 5626852 A. 1997.
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(7) Zheng, F. C., Chen, Q. W., Hu, L., Yan, N., Kong, X. K.. Synthesis of sulfonic acid-functionalized Fe3O4@C nanoparticles as magnetically recyclable solid acid catalysts for acetalization reaction. Dalton Trans. 2014, 43, 1220–1227. (8) Agirre, I.; Güemez, M. B.; Ugarte, A.; Requies, J.; Barrio, V. L.; Cambra, J. F.; Arias P. L. Glycerol acetals as diesel additives: Kinetic study of the reaction between glycerol and acetaldehyde. Fuel Process. Technol. 2013, 116, 182–188. (9) Rahaman, M.; Graca, N. S.; Pereira, C. S. M.; Rodrigues, A. E. Thermodynamic and kinetic study of the production of oxygenated compounds: synthesis of 1,1-diethoxybutane catalyzed by amberlyst-15. Can. J. Chem. Eng. 2015, 93, 1990–1998. (10) Dosuna-Rodríguez, I.; Gaigneaux, E.M. Glycerol acetylation catalysed by ion exchange resins. Catal. Today 2012, 195, 14–21. (11) Rossa, V.; Pessanha, Y. S. P.; Díaz, G. C.; Cam̂ara, L. D. T.; Pergher, S. B. C.; Aranda, D. A. G. Reaction Kinetic Study of Solketal Production from Glycerol Ketalization with Acetone. Ind. Eng. Chem. Res. 2017, 56, 479–488. (12) Thomas, B.; Ramu, V. G.; Gopinath, S.; George, J.; Kurian, M.; Laurent, G.; Drisko, G. L.; Sugunan, S. Catalytic acetalization of carbonyl compounds over cation (Ce3+, Fe3+ and Al3+) exchanged montmorillonites and Ce3+-exchanged Y zeolites. Appl. Clay Sci. 2011, 53, 227–235. (13) Deutsch, J.; Martin, A.; Lieske, H. Investigation on heterogeneously catalysed condensations of glycerol to cyclic acetals. J. Catal. 2007, 245, 428–35. (14) Cheng, Y. X.; Zhou, Y. Y.; Zhang, J. D.; Fei, X. D.; Ma, T. Z.; Liang, X. Z. Synthesis of a novel solid acid with both sulfonic and carbonyl acid groups and its catalytic activities in acetalization. Chin. J. Chem. Eng. 2014, 22, 312–317. (15) Sudarsanam, P.; Mallesham, B.; Prasad, A. N.; P. S.; Reddy, B. M. Synthesis of bio-additive fuels from acetalization of glycerol with benzaldehyde over molybdenum promoted green solid acid catalysts. Fuel Process. Technol. 2013, 106, 539–545. (16) Lan, P.; Lan, L. H.; Xie, T.; Liao, A. P. Study on Synthesis of Novel Seven-membered-ring Acetals (Ketals) over HZSM-5 Catalyst. Chem. World. 2010, 9, 545–548. (in Chinese) (17) Guo, H.; Ren, Y. Z., Sun, X. L.; Xu, Y. D.; Li, X. M.; Zhang, T. C.; Kang, J. X.; Liu, D. Q. Removal of Pb2+ from aqueous solutions by a high-efficiency resin, Appl. Surf. Sci. 2013,
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283, 660–667. (18) Qian, J.; Zeng, Z. X.; Xue, W. L.; Guo, Q. G. Lead removal from aqueous solutions by 732 cation-exchange resin. Can. J. Chem. Eng. 2016, 94, 142–150. (19) Qian, J.; Qiu, M. Q.; Zeng, Z. X.; Xue, W. L. Study on Ion-exchange Behavior of Cu2+ and Ni2+ with a High-efficiency Resin. Desalin. Water Treat. 2017, 93, 152–162. (20) Qian, J.; Liu Y. W.; Xue, W. L.; Zeng, Z. X. Ion exchange kinetics of Mg(II) from aqueous solutions with 732 cation-exchange resin. Chem. Sci. Int. J. 2016, 17, 1–10. (21) Mahajani, S. M. Reactions of glyoxylic acid with aliphatic alcohols using cationic exchange resins as catalysts. React. Funct. Polym. 2000, 43, 253–268. (22) Güemez, M. B.; Requies, J.; Agirre, I.; Arias, P. L.; Barrio, V. L.; Cambra, J. F. Acetalization reaction between glycerol and n-butyraldehyde using an acidic ion exchange resin. Kinetic modeling. Chem. Eng. J. 2013, 228, 300–307. (23) Fredenslund, A.; Jones, R. L.; Prausnitz, J. M. Group contribution estimation of activity coefficients in nonideal liquid mixtures. AIChE J. 1975, 21, 1086–1099. (24) Fredenslund, A.; Gmehling, J.; Rasmussen, P. Vapor-Liquid Equilibria Using UNIFAC: a group contribution method. Elsevier Scientific Pub. Co., Amsterdam, 1977, 1–380. (25) Gmehling, J.; Rasmussen, P.; Fredenslund, A. Vapor liquid equilibria by UNIFAC group contribution revision and extension. 2. Ind. Eng. Chem. Process Des. Dev. 1982, 21,118–127. (26) Nanda, M. R.; Yuan, Z. S.; Qin, W. S.; Ghaziaskar, H. S.; Poirier, M. A.; Xu, C. C. Thermodynamic and kinetic studies of a catalytic process to convert glycerol into solketal as an oxygenated fuel additive. Fuel 2014, 117, 470–477. (27) Silva, V. M. T. M.; Rodrigues, A. E. Synthesis of diethylacetal: thermodynamics and kinetic studies. Chem. Eng. Sci. 2001, 56, 1255–1263. (28) Silva, V. T. M.; Rodrigues, A. E. Kinetic studies in a batch reactor using ion exchange resin catalysts for oxygenates production: the role of mass transfer mechanisms. Chem. Eng. Sci. 2006, 61, 316–331. (29) Pereira, C. S. M.; Pinho, S. P.; Silva, V. T. M.; Rodrigues, A. E. Thermodynamic Equilibrium and Reaction Kinetics for the Esterification of Lactic Acid with Ethanol Catalyzed by acid ion exchange resin. Ind. Eng. Chem. Res. 2008, 47, 1453–1463.
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Table 1. Physicochemical properties of 732 cation-exchange resin. Properties
Value
Matrix
Styrene divinylbenzene copolymer
Total exchange capacity
≥4.60 mmol·g-1 (Na+ form)
Particle size
0.3-1.25 mm
Max. operating temp
393 K
pH range
1-14 (depending on application)
Surface areaa
443.78 m2·g-1
Pore diametrea
1.80 nm
Acid sites amountb
3.39 mmol·g-1
Acid sites density
7.65 µmol·m-2
a
Measured by N2 isotherm adsorption.
b
Measured by neutralization titration with aqueous NaOH solution.
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Table 2. Thermodynamic equilibrium composition and equilibrium constants. T (K)
293.15
303.15
318.15
333.15
xAe
0.2741±0.0051
0.2844±0.0092
0.2989±0.0047
0.3133±0.0025
xBe
0.1831±0.0051
0.1935±0.0093
0.2080±0.0048
0.2224±0.0025
xCe
0.2714±0.0051
0.2610±0.0093
0.2465±0.0048
0.2321±0.0026
xDe
0.2714±0.0051
0.2610±0.0093
0.2465±0.0048
0.2321±0.0026
Kx
1.4666
1.2382
0.9777
0.7733
γA
1.4264
1.4356
1.4477
1.4588
γB
1.9048
1.8915
1.8711
1.8490
γC
1.3791
1.3929
1.4128
1.4332
γD
2.2291
2.2029
2.1697
2.1409
Kγ
1.1314
1.1300
1.1316
1.1376
Ke
1.6594
1.3993
1.1063
0.8797
Table 3. Influence of catalyst particle size on equilibrium conversion of 1, 4-butanediol. Particle size (μm)
315
365
640
1045
Conversion (%)
54.56
54.24
55.33
53.88
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Table 4. Modeling parameters of ER kinetic model with adsorption of 1, 4-butanediol. Temperature (K)
k1 (mol·g-1·min-1)
KB
KD
293.15
0.0086±0.0003
1.874±0.073
13.799±0.534
303.15
0.0167±0.0004
1.737±0.046
11.098±0.293
318.15
0.0357±0.0016
1.580±0.074
8.056±0.368
Table 5. Kinetic rate equation and parameters of the ketalization reaction. kinetic rate equation
r = k1 (aA aB − aC aD / K e ) / (1+ K B aB + K D aD )
equilibrium constant Ke (dimensionless)
K e = 8.537 ×10−3 exp(1545.7 / T )
reaction rate constant k1 (mol·g-1·min-1)
k1 = 5.889 ×10 5 exp(−5278.8 / T )
adsorption constants KB (dimensionless)
K B = 0.2152 exp(633.6 / T )
adsorption constants KD (dimensionless)
K D = 0.01457exp(2008.9 / T )
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Scheme 1. Ketalization reaction scheme of cyclohexanone and 1,4-butanediol.
Figure 1. Schematic picture of batch reactor for the ketalization reaction.
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Figure 2. Correlation of reaction equilibrium constant with temperature.
Figure 3. Effect of agitation speed on conversion of 1, 4-butanediol.
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Figure 4. Effect of temperature on conversion of 1, 4-butanediol.
Figure 5. Effect of initial molar ratio of reactants on conversion of limiting reactant.
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Figure 6. Effect of catalyst loading on conversion of 1, 4-butanediol.
Figure 7. Parity plot between calculated and experimental obtained reaction rates.
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Figure 8. Plot of ln k1, ln KB and ln KD vs 1/T for ketalization reaction.
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