Investigation on co-hydropyrolysis of heavy bio-oil with degradable plastics

Abstract

Reducing the acidity and viscosity of heavy bio-oil is one of the main tasks of bio-oil treatment. The sharp increase in the consumption of degradable plastics requires an effective route for their recycling. In this study, heavy bio-oil was used as the organic solvent of degradable plastics in a co-hydropyrolysis process with lower temperature in reaction kettle. Employing an orthogonal experimental design, and with the maximum total energy yield of co-hydropyrolysis process as the target, the optimal reaction parameters were determined by the degradable plastics all pyrolyzed. The liquidity of the liquid phase increased significantly and the viscosity is decreased. The hydrocarbon content in the liquid-phase products increased, and the amount of organic acids decreased significantly from 183.9 mg/g to 72.1 mg/g according to KOH solution titration. A total energy yield of 86.27% was achieved with a calorific value of the bio-oil product of 25.6 MJ/kg and coke product of 26.93 MJ/kg. The active component of the iron-based oxygen carrier is completely transformed from FeO to Fe3O4, which prompted the pyrolysis of oxygen-containing organic matter and the uptake of the products by the fuel oil. This work developed a way to resource the heavy bio-oil and degradable plastics.