posted on 2022-12-23, 15:05authored byHeather
O. LeClerc, Jeffrey R. Page, Geoffrey A. Tompsett, Sydney F. Niles, Amy M. McKenna, Julia A. Valla, Michael T. Timko, Andrew R. Teixeira
Hydrothermal liquefaction (HTL) is a promising strategy
for the
conversion of energy-dense waste streams to fuels. Mixed-feed HTL
aggregates multiple feed streams to achieve greater scales that capitalize
on local resources, hence lowering costs. The potential for new pathways
and products upon feedstock blending becomes a compounding level of
complexity when unlocking emergent chemistries. Food and green waste
streams were evaluated under HTL conditions (300 °C, 1 h) to
understand the effect of feed molecular composition on product distributions
and mechanisms. Thousands of emergent chemical compounds were detected via Fourier transform ion cyclotron resonance mass spectrometry,
ultimately leading to the emergence of two dominant outcomes. First,
the presence of small amounts of food waste into green waste results
in substantial decarboxylation and subsequent polymerization to biocrude
than chars. Second, in the other limit, small amounts of green waste
promote the capping of oxygenates into the biodiesel range, such as
with the emergence of fatty acid methyl esters.