Phase equilibrium engineering in biorefinery reactive systems: n-alkanol acety-lation

FRANCISCO A. SÁNCHEZ; SELVA PEREDA

París (el congreso fue realizadod de manera virtual mediante la plataforma Lava Virtual World)

Simposio; 31st European Symposium on Applied Thermodynamics ESAT 2021; 2021

IFP Energies Nouveles & Paris Mines Tech

In recent years, the need to diversify thedemand for liquid fuels has promoted the research in new and advanced biofuels.In addition, the valorisation of available renewable resources also calls forother products like solvents and value-added chemicals, to make the wholeprocess competitive in today?s market. In this context, the synthesis paths ofvarious bio-based value-added products involve reversible chemical reactions;therefore, process development and optimization require modelling the chemicalequilibrium (CE) of these systems, as well as simultaneous chemical and phaseequilibrium (CPE). There are many other applications of such models, forexample in the biphasic dehydration and/or hydrogenation reactors or in thewell-developed reactive distillation units, where phase separation is design toimprove the reaction yield. In this sense, esterification andtransesterification reactions are found in many productive pathways ofvalue-added products; such as, biodiesel, glycerol acetates, or valericbiofuels, to name a few. In any case, CE calculation requires, a priori, theformation Gibbs energy of each component involved in the reaction (Δgf) or the equilibriumconstant (K), which is equivalent tothe former. However, this information is not always available and hence, K is frequently correlated to CE experimentaldata (Bucalá et al., 2006; Schmid et al., 2008). There are other examples that,even though K is available, it isdisregarded due to parametric sensitivity and again K is correlated with CE experimental data using a thermodynamic modeltuned to phase equilibrium data (Grob & Hasse, 2014; Riechert et al., 2015).In particular, Riechert et al. discuss the influence of the physical formalismof the thermodynamic model, and conclude that those models that take intoaccount the molecular phenomena that occur in the multicomponent mixture achievea better K correlation. However, theydo not contrast their results against literature values ​​of K or Δgf.In this work, we challenge the GroupContribution with Association Equation of State (Sánchez et al., 2011) (GCAEOS) to predict the CPE of various acetylation reactions of n-alkanols based on Δgfig reported inliterature and experimental databases (Rowley et al., 2003), i.e. withoutcorrelating CE data. We select this model system because of the large number ofexperimental data available and the advantage of using a group contributionmodel to assess homologous series. Despite of the parametric sensitivity of thesesystems CE, we show that the GCA EOS can predict CPE of this homologous series.ReferencesBucalá, V., Foresti, M.L., Trubiano, G.,Ferreira, M.L., Briozzo, M., Bottini, S.B., 2006. Enzyme Microb. Technol. 38, 914?920.Grob, S., Hasse, H., 2004. J. Chem. Eng.Data 50, 92?101.Riechert, O., Husham, M., Sadowski, G.,Zeiner, T., 2015. AIChE J.61, 3000?3011.Rowley, R.L.,Wilding, W.V., Oscarson, J.L., Yang, Y., Zundel, N.A., Daubert, T.E., Danner, R.P.,2003. DIPPR Data Compilation of Pure Compound Properties, New York.Sánchez, F.A.,Pereda, S., Brignole, E.A., 2011. Fluid Phase Equilib.306, 112?123.Schmid, B., Döker, M., Gmehling, J.,2008. Ind. Eng. Chem. Res. 47, 698?703.