Chemistry and Kinetic Modeling of Feedstock Dependant Thermal Deoxygenation Reactions

Thermal DeOxygenation (TDO) refers to a simple, non-catalytic, process which produces highly deoxygenated crude oils from levulinic and formic acids derived from biomass feedstock.  The primary reaction is a single-step decomposition reaction which converts the neutralized biomass hydrolyzate to crude hydrocarbons, chars, CO₂, water and volatiles at 450°C and at ambient pressure.  This reaction pathway promises to reduce the cost and complexity associated with fuel production within a biorefinery. 

TDO decomposition reactions are sensitive to levulinic:formic acid ratio, choice of cation and solids morphology.  In this work, thermogravimetric analysis (TGA) is applied to levulinate:formate salts at a 1:1 molar ratio using economical cations from each major metal groupings.  Two techniques are used in this analysis; first, the Distributed Activation Energy Model (DAEM) is applied to temperature ramp data on powder samples using a micro TGA balance to demonstrate reaction kinetics.  In the second, iso-thermal methods are used to understand mass-transfer and kinetic limitations on reaction kinetics using a custom macro-scale TGA apparatus.  Reaction gas composition is monitored using continuous FTIR and mass speciation techniques.  TDO reaction efficiency, reaction pathway and kinetic parameters are presented as a function of feedstock composition.