Co-production of bio-oil and propylene through the hydrothermal liquefaction of polyhydroxybutyrate producing cyanobacteria
journal contributionposted on 22.07.2019, 12:19 by Jonathan L. Wagner, Rachel Bransgrove, Tracey A. Beacham, Michael J. Allen, Katharina Meixner, Bernhard Drosg, Valeska P. Ting, Christopher J. Chuck
In this investigation, PHB producing cyanobacteria were converted through hydrothermal liquefaction (HTL) into propylene and a bio-oil suitable for advanced biofuel production. HTL of model compounds demonstrated that in contrast to proteins and carbohydrates, which react to produce a range of alternative intermediates, no synergistic effects were detected when converting PHB in the presence of algal biomass. Subsequently, Synechocystis cf. salina, which had accumulated 7.5 wt% PHB was converted via HTL (15 % dry weight loading at 340 °C). The reaction gave an overall propylene yield of 2.6 %, higher than that obtained from the analogous model compounds, in addition to a bio-oil with a low total nitrogen content of 4.6 %. No propylene was recovered from the alternative non-PHB producing cyanobacterial strains, Anabaena, Spirulina or Synechococcus, suggesting that PHB is the sole source of propylene. PHB producing microorganisms could therefore be used as a feedstock for a biorefinery to produce polypropylene and advanced biofuels, with the level of propylene being directly proportional to the accumulated amount of PHB.
- Aeronautical, Automotive, Chemical and Materials Engineering
- Chemical Engineering