Process modelling for sustainable production of bio-oil from waste biomass

The use of bio-based feedstocks is necessary, since industries still rely on fossil fuels or food-competitive feedstocks. Aim of this work is the design of an integrated process consisting of liquefaction and pyrolysis processes that use waste biomass for the production of biopolyol and biophenolic compounds for bio-based polyurethane (PU) and phenol-formaldehyde (PF) materials production. Aspen Plus models were developed using power-law kinetics for the pyrolysis process, validating literature-based results, with maximum error of 10 % showcasing the good predictability of the power-law kinetics. The integrated liquefaction and pyrolysis process was then modelled based on our experimental results, showing 77 % biopolyols yield after liquefaction and 59 % bio-oil yield after pyrolysis, which consisted of approximately 2.3 % phenols from the compounds detected. The modelling of components distribution of the bio-oil had a maximum error of 13 %. Lastly, an energy optimisation study was conducted in Aspen Plus, utilising the hot outlet stream from pyrolysis to heat the feedstock before entering the pre-heating step, reducing in that way the heating load of the heater by 13 kW. Future studies aim on a more detailed integrated liquefaction-pyrolysis process flow diagram to perform techno-economical and life-cycle analysis for the generation of bio-oil rich in biopolyols and phenolics.