Reaction kinetics of glycerol acetal formation via transacetalization with 1,1-diethoxyethane Xi Hong a , Omar McGiveron a , Aspi K. Kolah a , Alvaro Orjuela b , Lars Peereboom a , Carl T. Lira a , Dennis J. Miller a,⇑ a Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States b Departamento de Ingeniería Química, Universidad Nacional de Colombia, Ciudad Universitaria, Bogotá, Colombia highlights " Describe potential for glycerol acetals as chemical and fuel intermediates. " Identify conditions for glycerol acetal formation in high selectivity. " Characterize undesirable side products that reduce selectivity. " Report kinetics of glycerol acetal formation over Amberlyst catalyst. article info Article history: Received 23 October 2012 Received in revised form 16 January 2013 Accepted 23 January 2013 Available online 18 February 2013 Keywords: Glycerol Acetals Transacetalization Kinetics 1,1-Diethoxyethane abstract The kinetics of glycerol transacetalization with 1,1-diethoxyethane in ethanol over Amberlyst-15 cationic exchange resin catalyst at 25–40 °C have been investigated. The reaction must be run with DEE as the limiting reactant to avoid over-acetalization of glycerol, and below 50 °C to avoid formation of byprod- ucts from DEE such as ethyl vinyl ether. A second order kinetic model describes the transacetalization reaction satisfactorily with a rate constant of 1.1  10 4 m 6 /kmol/kg cat/s at 40 °C and an activation energy of 58.6 kJ/mol. The equilibrium constant for the reaction is 900 kmol/m 3 at 40 °C, and the heat of reaction is estimated at 20.6 kJ/mol. The reverse reaction has little influence on rate at reactant con- versions less than 50%. The model and reaction conditions identified provide a framework to develop and better understand processes for glycerol acetalization. Ó 2013 Published by Elsevier B.V. 1. Introduction The global growth in biodiesel production over the past decade has led to the availability of significant quantities of glycerol as a byproduct of the triglyceride transesterification process. The price of high purity glycerol in the US dropped from $1.00/lb to $0.40/lb between 1995 and 2005 [1], but has since rebounded as chemical manufacturers develop new uses for the inexpensive feedstock in- stead of treating it as an environmental liability [2,3]. Zhou and coworkers [4] reviewed some of the pathways for obtaining various useful chemicals such as epichlorohydrin and propylene glycol from glycerol. In addition to chemicals, glycerol can be converted to effective fuel additives that improve combus- tion and emission properties and provide additional energy con- tent. Fernando et al. [2] discussed the possibility of blending glycerol derivatives such as propanediol and propanol with gaso- line as an automotive fuel. They obtained fuel blends with high en- ergy value and with octane numbers exceeding 100. However, they did not investigate the cold weather properties of those fuel mixtures. Noureddini [5] developed a process to derive ethers from glyc- erol and isobutylene using strong acid catalysts. He found that mixing these ethers with biodiesel decreases its viscosity and cloud point. Others [6] reported that glycerol ethers also reduce particulate emissions from diesel and biodiesel combustion. Glycerol acetates have also been examined as fuel additives [7–12]. Delfort et al. [7,8] reported a 30% reduction in particulate emissions upon addition of 5–20 wt% glycerol acetals to petroleum diesel fuel. Delgado Puche [9] described the formation of glycerol acetal and glycerol acetate mixtures, and found that adding them to biodiesel in concentrations of 0.5–20 wt% reduced particulate emissions, pour point, and viscosity at low temperatures. Paulo et al. [10] reported the synthesis of glycerol acetals with C 4 –C 10 1385-8947/$ - see front matter Ó 2013 Published by Elsevier B.V. http://dx.doi.org/10.1016/j.cej.2013.02.023 ⇑ Corresponding author. Tel.: +1 517 353 3928; fax: +1 517 432 1105. E-mail address: millerd@egr.msu.edu (D.J. Miller). Chemical Engineering Journal 222 (2013) 374–381 Contents lists available at SciVerse ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej