|Hary Sulistyo||Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika No. 2 Kampus UGM Bulaksumur, Yogyakarta, Indonesia|
|Didan Prasiasda Priadana||Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika No. 2 Kampus UGM Bulaksumur, Yogyakarta, Indonesia|
|Yasinta Wahyu Fitriandini||Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika No. 2 Kampus UGM Bulaksumur, Yogyakarta, Indonesia|
|Muhammad Mufti Azis|
The increase of biodiesel production would cause an increase of glycerol as by-products. In the present study, utilization of glycerol by-products to form solketal using Indion 225 Na as a catalyst was investigated. The intrinsic kinetic data were taken in a batch reaction. The results showed that the temperatures and catalyst concentration have a significant influence on the conversion of glycerol. However, varying the acetone to glycerol ratio only had a marginal impact on glycerol conversion. A kinetic model based on Eley Rideal mechanism was developed to describe the reaction mechanism over the catalyst. The simulation results of glycerol conversion were compared to experimental data at temperatures from 308 K to 328 K. From the kinetic model, it was found that the pre-exponential factor of 2.59 min-1, activation energy of 21.16 kJ/mol, acetone adsorption equilibrium of 0.62, and solketal desorption equilibrium of 0.03 were obtained. Comparison between the experimental and calculated glycerol concentrations showed that the model described the data well within the temperature range of 308 K to 328 K.
Acetone; Catalyst; Glycerol; Kinetic; Solketal
There has been growing interest in increasing the use of biodiesel as a renewable transportation fuel in Indonesia. According to the National Energy Plan (2017), Indonesia is expected to increase the portion of renewable energy from 23% of total energy consumption in 2025 to 31.2% in 2050. The increase use of renewable energy is an important step for Indonesia as it strives to decrease its greenhouse gas emissions. The increase of biodiesel production in the country will be accompanied by a corresponding increase of glycerol as a by-product of biodiesel production. Typically, glycerol yields as high as 10 wt% from transesterification reactions are obtained during biodiesel production. Therefore, there is an urgent need to utilize glycerol as a raw material to produce value-added chemicals along with the increase of biodiesel production.
Many studies have reported the conversion of glycerol to produce various chemicals. Tan et al. (2013) and Kong et al. (2016) proposed glycerol conversion to 1,3-propanediol which plays an important role on production of polymers, cosmetic, food, lubricants and medicine. In addition, it can be converted to acrolein as an intermediate of acrylic acid production. Glycerol can also be converted to hydrogen and syngas as a platform for various chemicals production. A plasma electrolysis method to produce hydrogen was reported by Saksono et al. (2012). Regarding hydrogen production from glycerol, Slamet et al. (2015) used a TiO2 P25 photocatalyst modified with metals such as Platinum (Pt), Copper (Cu), and non–metal Nitrogen doping.
In another study, Leong et al. (2016) reported the pyrolysis of crude glycerol using a microwave heating technique to produce pyrolyzed liquid, which can be used as fuels in combustion systems. Glycerol could also be converted to glycerol carbonate (Okoye and Hameed, 2016). Glycerol carbonate is known as a green organic solvent, which has a high boiling point. Ketalization of glycerol with acetone to produce an oxygenated compound such as solketal is an interesting question to consider, as solketal is known as a promising fuel additive (Reddy et al., 2011; Nanda et al., 2016).
Solid catalyst is generally preferred for solketal production as it improves the separation of catalyst. Specifically, zirconia and promoted zirconia catalysts have been used for the ketalization of glycerol (Reddy et al., 2011). Reddy et al. (2011) reported the promoted zirconia catalyst exhibited promising catalytic activity with the highest glycerol conversion of 98% using a sulphate zirconia catalyst at room temperature. da Silva et al. (2017) used SnF2 as catalyst for the ketalization of glycerol with propanone to form solketal to obtain ca. 97% of glycerol conversion at ambient temperature. Nanda et al. (2014) reported on the use of ethanol as a solvent in glycerol acetylation using Amberlyst 35 as a catalyst, which produced a solketal yield as high as 74%. The mesoporous 5% Ni-1%Zr/AC catalyst has also been used for acetalization of glycerol without solvent, which yielded complete glycerol conversion (Khayoon and Hameed, 2013). Some catalysts, such as zeolite Beta, Amberlyst 15, and p-toluene sulfonic acid, have also been used for glycerol acetalization with acetone (da Silva et al., 2009). The results showed that the zeolite Beta with a high ratio of Si to Al attained a glycerol conversion of more than 95%. It was also found that the high ratio of Si to Al is beneficial as it caused the zeolite to block the entry of water into the pores.
Temperatures higher than 313 K are typically needed to obtain sufficient conversion to force water removal and to drive the forward reaction to produce solketal (Esteban et al., 2015). Vicente et al. (2010) investigated acetalization using crude glycerol with an SBA-15 catalyst and found high glycerol conversion. To drive the reaction equilibrium, they proposed a new method for water removal by refluxing the flask followed by water vaporization under vacuum pressure. Manjunathan et al. (2015) also produced solketal by reacting glycerol with acetone at an ambient temperature by using a modified beta catalyst. They obtained a glycerol conversion of 87.1% by using a catalyst loading of 7.5%. The pseudo homogeneous kinetics model for ketalization of glycerol using H-BEA as a catalyst was proposed by Rossa et al. (2017). At a temperature range of 313 K to 353 K, the activation energies for forward and reverse reactions were 44.77 kJ/mol and 41.40 kJ/mol, respectively. Nanda et al. (2014) investigated the kinetics of ketalization of glycerol at 293-323 K with Amberlyst 35 as a catalyst. They proposed a Langmuir-Hinshelwood kinetic model and obtained an activation energy of 55.6 kJ/mol. Overall, these studies show that the temperatures between 300-350 K are needed for glycerol conversion. As a result, kinetics studies with solid catalyst should be investigated within that range of temperatures.
The purpose of the present study was to develop a kinetics model of solketal synthesis from glycerol and acetone over an Indion 225 Na catalyst. Indion 225 Na is known to be an inexpensive ion exchanger compared to Amberlysts, and it is more accessible on the market. To achieve our proposed aim, glycerol conversion data were taken while varying reaction conditions such as temperature, catalyst concentration, stirrer speed, and acetone to glycerol ratios (Priadana, 2017; Fitriandini, 2017).
The acetalization of glycerol
has been investigated in the present study by using the ion exchange resin
Indion 225 Na. Temperature and catalyst loading significantly influenced the
glycerol conversion rate. However, the molar ratio of acetone to glycerol had
negligible effects on the solketal formation. The influence of stirrer speed
was also negligible. As a result, it confirmed the absence of mass transfer
resistance under high stirring rate. Thus, the reaction rate can be assumed to
be measured under kinetic regime. A kinetic model based on the Eley-Rideal
mechanism was developed to describe the reaction mechanism over the catalyst.
The simulation results were compared to glycerol experimental data at
temperatures ranging from 308 K to 328 K. From parameter calculations, we found
a pre-exponential factor of 2.59 min-1, an activation energy of
21.16 kJ/mol, an acetone adsorption equilibrium of 0.62, and solketal
desorption equilibrium of 0.03. Comparison of glycerol concentrations between
the simulated and experimental data showed that the model could describe the
data well within the temperature range of 308-328 K.
We would like to acknowledge the financial support received from the Ministry of Research, Technology and Higher Education of the Republic of Indonesia through the PDUPT Scheme, with contract number 124/UN1/DITLIT/DIT-LIT/LT/2018.
Agirre, I., Güemez, M.B., Ugarte, A., Requies, J., Barrio, V.L., Cambra, J.F., Arias, P.L., 2013. Glycerol Acetals as Diesel Additives: Kinetic Study of the Reaction between Glycerol and Acetaldehyde. Fuel Processing Technology, Volume 116, pp. 182–188
da Silva, C.X.A., Goncalves, V.L.C., Mota, C.J.A., 2009. Water Tolerant Zeolite Catalyst for the Acetalization of Glycerol. Green Chemistry, Volume 11(1), pp. 38–41
da Silva, M.J., Rodrigues, F.A., Julio, A.A., 2017. SnF2-Catalyzed Glycerol Ketalization: A Friendly Environmentally Process to Synthesize Solketal at Room Temperature Over on Solid and Reusable Lewis Acid. Chemical Engineering Journal, Volume 307, pp. 828–835
Esteban, J., Ladero, M., Garcia-Ochoa, F., 2015. Kinetic Modelling of the Solventless Synthesis of Solketal with a Sulphonic Ion Exchange Resin. Chemical Engineering Journal, Volume 269, pp. 194–202
Fitriandini, Y.W., 2017. Solketal Synthesis from Glycerol and Acetone using Indion 225 Na as Catalyst (the Effect of Temperature and Stirring Speed). Research Report of Chemical Reaction Engineering and Catalysis Lab., Department of Chemical Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia
Hong, X., Mc Giveron, O., Kolah, A.K, Orjuela, A., Peereboom, L., Lira, C.T., Miller, D.J., 2013. Reaction Kinetics of Glycerol Acetal Formation via Transacetalization with 1,1-diethoxyethane. Chemical Engineering Journal, Volume 222, pp. 374–381
Khayoon, M.S., Hameed, B.H., 2013. Solventless Acetalization of Glycerol with Acetone to Fuel Oxygenates over Ni-Zr Supported on Mesoporous Activated Carbon Catalyst. Applied Catalysis A: General, Volume 464-465, pp. 191–199
Kong, P.S., Aroua, M.K., Wan Dawud, W.M.A., 2016. Conversion of Crude Glycerol and Pure Glycerol into Derivatives: A Feasibility Evaluation. Renewable and Sustainable Energy Reviews, Volume 63, pp. 533–555
Leong, S.K., Lam, S.L., Ani, F.N., Ng, J., Chong, C.T., 2016. Production of Pirolyzed Oil from Crude Glycerol using a Microwave Heating Technique. International Journal of Technology, Volume 7(2), pp. 323–331
Manjunathan, P., Maradur, S.P., Halger, A.B., Shanbhag, G.V., 2015. Room Temperature Synthesis of Solketal from Acetalization of Glycerol with Aceton: Effect of Crystallite Size and the Role of Acidity of Beta Zeolite. Journal of Molecular Catalysis A: Chemical, Volume 396, pp. 47–54
Nanda, M.R., Yuan, Z., Qin, W., Ghaziaskar, H.S., Poirier, M.A., Xu, C., 2014. Thermodynamic and Kinetic Studies of a Catalytic Process to Convert Glycerol into Solketal as an Oxygenated Fuel Additive. Fuel, Volume 117 Part A, pp. 470–477
Nanda, M.R., Zhang, Y., Yuan, Z., Qin, W., Ghaziaskar, H.S., Xu, C., 2016. Catalytic Conversion of Glycerol for Sustainable Production of Solketal as a Fuel Additive: A Review. Renewable and Sustainable Energy Reviews, Volume 56, pp. 1022–1031
Okoye, P.U., Hameed, B.H., 2016. Review on Recent Progress in Catalytic Carboxylation and Acetylation of Glycerol as a Byproduct of Biodiesel Production. Renewable and Sustainable Energy Reviews, Volume 53, pp. 558–574
Priadana, D.P., 2017. Solketal Synthesis from Glycerol and Acetone using Indion 225 Na as Catalyst (the Effect of Catalyst Concentration and Molar ratio of Acetone to Glycerol ). Research Report of Chemical Reaction Engineering and Catalysis Lab., Department of Chemical Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia
Reddy, P.S., Sudarsanam, P., Mallesham, B., Raju, G., Reddy, B.M., 2011. Acetalisation of Glycerol with Acetone over Zirconia and Promoted Zirconia Catalysts under Mild Reaction Conditions. Journal of Industrial and Engineering Chemistry, Volume 17(3), pp. 377–381
Rossa, V., Pessanha, Y.S.P., Diaz, G.C., Camara, L.D.T., Pergher, S.B.C., Aranda, D.A.G., 2017. Reaction Kinetic Study of Solketal Production from Glycerol Ketalization with Acetone. Industrial and Engineering Chemistry Research, Volume 56(2), pp. 479–488
Saksono, N., Ariawan, B., Bismo, S., 2012. Hydrogen Production System using Non-thermal Plasma Electrolysis in Glycerol-KOH Solution. International Journal of Technology, Volume 3(1), pp. 8–15
Shirani, M., Ghaziaskar, H.S., Xu, C., 2014. Optimization of Glycerol Ketalization to Produce Solketal as Biodiesel Additive in Continuous Reactor with Subcritical Acetone using Purolite PD206 as Catalyst. Fuel Processing Technology, Volume 124, pp. 206–211
Slamet, S., Kusrini, E., Afrozi, A.S., Ibadurrohman, M., 2015. Photocatalytic Hydrogen Production from Glycerol-water over Metal Loaded and Non-metal Doped Titanium Oxide. International Journal of Technology, Volume 6(4), pp. 520–532
Tan, H.W., Abdul Azis, A.R., Aroua, M.K., 2013. Glycerol Production and Its Applications as a Raw Material: A Review. Renewable and Sustainable Energy Reviews, Volume 27, pp. 118–127
Trifoi, A.R., Agach, P.S., Pap, T., 2016. Glycerol Acetals and Ketals as Possible Diesel Additives. A Review of Their Synthesis Protocols, Renewable and Sustainable Energy Reviews, Volume 62, pp. 804–814
Vicente, G., Melero, J.A., Morales, G., Paniagua,
M., Martin, E., 2010. Acetalisation of Bio-Glycerol with Acetone Produce Solketal
over Sulfonic Mesostructured Silicas. Green
Chemistry. Volume 12(5), pp. 899–907