This
study proposes a novel approach to design and evaluate surrogates
for liquid fuels, aimed at replicating their evaporative and sooting
behaviors. The method was demonstrated for a commercial heating oil.
The lack of surrogates found in the literature for this relevant fuel,
in addition to its physicochemical complexity, was the primary reason
for its choice to test the proposed method. A first surrogate aiming
to emulate the evaporative behavior of the target fuel was designed
through the combination of a theoretical evaporation model and experimental
tests. The second surrogate was formulated to replicate the sooting
behavior of heating oil, whereas a third surrogate aimed to match
the physicochemical properties relevant for both processes. The so-designed
surrogates were validated afterward by means of single-droplet evaporation
tests under high-temperature conditions. The obtained evaporation
curves served as a benchmark for evaluating the evaporative characteristic,
whereas an aspirating probe collecting all of the soot produced at
a high-temperature and reducing atmosphere was used for the validation
of the sooting tendency. It was found that surrogates specifically
designed to match the evaporative and sooting behaviors of the target
fuel displayed a remarkably good agreement when validated against
experimental data for heating oil. Overall, the obtained results confirmed
the validity of the methodologies proposed for surrogate formulation,
combining predictive methods and droplet evaporation tests at high
temperatures.
This work aims to study the bio-oils obtained from the catalytic co-pyrolysis of waste polymers and a residual biomass (grape seeds, GS). For that purpose, the organic liquid fractions produced in an auger reactor were thoroughly characterized in two steps, obtaining in the first place their main physicochemical properties as well as their chemical compositions, and second, their droplet combustion behaviors. Both the polymer type (waste tires or polystyrene, WT and PS, respectively) and the nature of the low-cost, calcium-based catalyst used (Carmeuse limestone, calcined dolomite, or an inert material such as sand) were studied. A significant improvement in the physicochemical properties of the bio-oils was obtained when using a catalyst, with lower viscosity, density, and oxygen content. These beneficial effects were more marked for the bio-oil produced with the Carmeuse catalyst, presumably due to the higher prevalence of aromatization and hydro-deoxygenation reactions. When changing the polymer source from WT to PS, a considerable increase in the aromatic content and a viscosity reduction were noted. The droplet combustion tests revealed the consistent occurrence of microexplosions for all of the studied bio-liquids, these bursting events being more violent for the GS−PS oil. Regarding the evaporation behavior, this liquid also yielded significantly higher burning rates during the initial heatup phase, in agreement with its richer composition in volatile compounds such as styrene. These results point to this fuel as the one with the best global combustion behavior from all of the explored bio-oils. The GS−WT liquids showed much closer features among them, although with noticeable differences depending on the catalyst used. A more volatile behavior was observed for GS−WT Carmeuse, followed by GS−WT dolomite and GS−WT sand, strengthening thus the previously reported improvements in physicochemical properties. Finally, the propensity to form soot of these bio-oils was characterized through a soot probe, which revealed a higher soot yield for the bio-liquids produced with the Carmeuse catalyst.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.