Co-pyrolysis of corn stalks and plastic waste: Chemical composition of the pyrolyzates as a base for producing environmentally sustainable fuels

In this study pyrolysis and co-pyrolysis experiments involving lignocellulosic corn stalks (CS) sam-ples and selected plastic waste fractions (high density polyethylene (HDPE) and polystyrene (PS)) were conducted at various mixing ratios. The main objective was to evaluate how the composition of the feedstock affects the yield and composition of the resulting pyrolysis products, by developing a sustainable method for the management of both biomass and plastic waste through the production of valuable oils and chemicals. This study contributes to a transitional approach for plastic waste management, given the anticipated reduction in the usage of plastic materials in the future. The co-pyrolysis mixtures demonstrated synergistic effects between the feedstocks, with plastic waste serving as hydrogen donors and enhancing the yield of CS pyrolysis products. Moreover, the products from plastic waste exhibited a significant predominance over those from CS, constituting ca. 66.6 and 85.6 % in the 1:1 CS/HDPE and CS/PS mixtures, respectively. This is particularly beneficial considering the elevated oxygen content in the CS products, which can contribute to heightened acidity and corrosion in the resulting synthetic bio-oil. This study reveals valuable insights into the formation of synthetic bio-oils by designing the chemical composition and optimising the pyrolysis yield.