Co-production of fully renewable medium chain α-olefins and bio-oil via hydrothermal liquefaction of biomass containing polyhydroxyalkanoic acid.

Medium chain-length linear α-olefins ( mcl -LAO) are versatile precursors to commodity products such as synthetic lubricants and biodegradable detergents, and have been traditionally produced from ethylene oligomerization and Fischer-Tropsch synthesis. Medium chain-length polyhydroxyalkanoic acid ( mcl -PHA) can be produced by some microorganisms as an energy storage. In this study, Pseudomonas putida biomass that contained mcl -PHA was used in HTL at 300 °C for 30 min, and up to 65 mol% of mcl -PHA was converted into mcl -LAO. The yield and quality of the bio-oil co-produced in the HTL was remarkably improved with the biomass rich in mcl -PHA. Experiments with extracted mcl -PHA revealed the degradation mechanism of mcl -PHA in HTL. Overall, this work demonstrates a novel process to co-produce mcl -LAO and bio-oil from renewable biomass.