Solvothermal co-liquefaction of sugarcane bagasse and polyethylene under sub-supercritical conditions: Optimization of process parameters

The co-liquefaction of mixtures of sugarcane bagasse and high density polyethylene (HDPE) in ethanol under subcritical and super-critical conditions was studied with the objective of finding optimal process conditions for bio-oil yield and overall conversion. Taguchi method was employed to design with 9 experiments to find the effect of 4 independent variables (temperature, reaction time, biomass to plastic composition and solvent-to-biomass ratio) on the co-liquefaction of plastic and biomass for total conversion and bio-oil yield. The optimal results showed 60 % conversion with bio-oil yield 32.3 % having HHV of bio-oil 29.6 MJ/kg respectively. The predicted model indicated a good fit with that of experimental data. Furthermore, detailed characterizations of bio-oils were carried out such as higher heating value (HHV), chemical composition, NMR analysis, elemental analysis, FTIR and thermogravimetric analysis. The co-liquefaction of sugarcane bagasse and polyethylene was found effective to improve the qualitative and quantitate features of products from the biomass.