Polyhydroxyalkanoates and biochar from green macroalgal Ulva sp. biomass subcritical hydrolysates: Process optimization and a priori economic and greenhouse emissions break-even analysis.

摘要: Abstract Although macroalgae biomass is an emerging sustainable feedstock for biorefineries, the optimum process parameters their hydrolysis and fermentation are still not known. In present study, simultaneous production of polyhydroxyalkanoates (PHA) biochar from green Ulva sp. examined, applying subcritical water Haloferax mediterranei fermentation. First, effects temperature, treatment time, salinity, solid load on PHA productivity were optimized following Taguchi method. Hydrolysis at 170 °C, 20 min residence 38 g L−1 salinity with a seaweed 5% led to maximum yield 0.104 g g−1 0.194 ± 1.23 g g−1 Ulva. Second, effect different initial culture densities was studied. An density 50 g L−1 volumetric 0.024 ± 0.002 g L−1 h−1 content 49.38 ± 0.3% w/w Sensitivity analysis shows that within 90% confidence, annual 148.14 g m−2 year−1 42.6 g m−2 year−1. Priori economic greenhouse gas break-even analyses done estimate revenues allowable emissions. The study illustrates hydrolysate using extreme halophiles coupled could become benign promising step in marine biorefinery.