Co-pyrolysis of seaweeds with waste plastics: modeling and simulation of effects of co-pyrolysis parameters on yields, and optimization studies for maximum yield of enhanced biofuels

Co-pyrolysis of Enteromorpha prolifera (EP) (seaweeds) with waste plastics (high density polyethylene (HDPE)) for maximum yield of enhanced biofuels has been investigated. Main and interaction effects of three effective co-pyrolysis parameters (pyrolysis temperature, feedstock blending ratio and heating rate) on bio-oil, char and gas yields were also modeled and simulated, respectively. Optimization studies using central composite rotatable experimental design were performed in Design Expert (R) Version 8.0.6 software to predict the optimal conditions of co-pyrolysis parameters for maximum yield of enhanced biofuels. Analysis of variance was carried out to determine whether the fit of multiple regressions was significant for second order models. Compositions of bio-oils and chars from the pyrolysis of EP, HDPE and their mixtures at different blending ratios were determined using gas chromatography-mass spectrometry analysis technique. Other important properties of oils and chars such as heating values, water contents, and specific gravity were also determined. Results of products' analysis revealed that synergistic effect exists between EP and HDPE during co-pyrolysis which led to enhanced seaweed biofuels. Statistical analysis' results unveiled that feedstock blending ratio, pyrolysis temperature and heating rate significantly influenced bio-oil and char yield rates.