| Description |
Lignocellulosic biomass can be upgraded via pyrolysis, yielding biochar as a value-added product, in addition to condensable liquid fractions known as pyrolysis oils; however, the utilization of these pyrolysis oils is hampered by high water content, instability, and corrosiveness. Oily biomass can be upgraded by extraction of oils and subsequent conversion to biodiesel; however, shortcomings of traditional biodiesel processes include the use of harshly acidic or basic reaction environments that require costly neutralization processes, as well as the need for expensive, high-quality feedstocks. In this work, a newly-developed ionic liquid catalyst is shown to have excellent potency for the esterification of free fatty acids (FFA) to produce biodiesel, affording the use of cheaper feedstocks traditionally seen as "waste" oils. It is also shown to achieve the esterification of acids in pyrolysis oil to partially mitigate the corrosiveness and instability of the bio-oil, allowing greater opportunity for downstream processing and utilization. Kinetic models describing the behavior of both reactions are derived and compared to the data. Notably, the kinetic treatment of pyrolysis oil exhibits remarkable accuracy for its simplicity relative to the complex composition of pyrolysis oil, with integer reaction orders definitively confirmed by experimental data. A novel coprocessing scheme that applies the catalyst to both reactions without an intermediate recovery step is developed and shown to allow both pyrolysis oil mitigation and the deacidification of high-FFA triglyceride oils to proceed in a single process, demonstrating the catalyst's broad potential for the upgrading of waste biomass. |
