(544dq) Thermodynamic and Kinetic Analysis of ?-Valerolactone Ring Opening in Multiphase Reactors

In the biomass processing landscape, γ-valerolactone (GVL) is a popular intermediate platform chemical that can be used to produce a range of fuels and chemicals through catalytic upgrading. One such process is the ring opening of GVL to form pentenoic acid (PEA) isomers, which are a family of C₅ alkene-acids, whose molecular weight and chemical flexibility make them appropriate for the production of polymers, solvents, and diesel fuels.

GVL ring opening is kinetically facile. It is proton-mediated, and it proceeds at relatively high rates in the presence of various homogeneous (e.g., H₂SO₄) and heterogeneous (e.g., H-ZSM-5) Bronsted acids. In order to avoid detrimental side reactions, such as decarboxylation and polymerization, it is desirable to carry out ring opening at low temperatures; however, the reaction is endothermic and severely constrained by chemical equilibrium under mild conditions. Our hypothesis is that a well-designed biphasic reactor can bypass this equilibrium constraint and deliver good PEA yields at low temperatures. Specifically, we propose that preferential solvation PEA in an extracting organic phase should drive high GVL conversions despite an unfavorable equilibrium position at low temperatures.

In order to design an appropriate reactor, it is essential to develop a comprehensive understanding of both solution thermodynamics and the kinetics of GVL ring opening in a range of solvent environments. To this end, we have performed extraction experiments to allow regression of empirical Margules parameters to estimate species activity coefficients in both aqueous and organic media, and we have studied the kinetics of GVL ring opening in both single and biphasic systems. Based on these results, biphasic reactors were simulated under a range of temperatures and solvent environments to identify operating conditions that can deliver improved single-pot yields of PEA on industrially tractable time scales. This poster focuses on recent progress in understanding thermodynamics and kinetics of ring opening reaction in the biphasic environments and discusses the significant factors that can influence the effectiveness of biphasic reactors.