Exploring the feasibility of Co-gasification of biomass and EVA from End-of-Life solar panels

The ongoing uptake of solar panel technology driven by the growing renewable energy use by society means their End-of-Life management is becoming an increasingly significant challenge. Ethylene vinyl acetate (EVA) is an integral component of solar panels and requires an effective management strategy during panel disposal. In this work, managing EVA waste by blending it with biomass and treatment by air gasification is examined. Additionally, the synergistic effects of adding EVA to biomass are explored to determine the potential benefits of combining this plastic waste with biomass. The influence of temperature (T), equivalence ratio (ER), and plastic-to-biomass ratio (P/B) on product distribution is assessed and any synergy arising from biomass integration identified. Response surface methodology (RSM) and analysis of variance (ANOVA) approaches were used to evaluate the interdependency of the variables with empirical correlations then developed to estimate the gas composition. Adding biomass to the EVA is found to enhance the thermal degradation of both feedstocks and reduce char yield with the synergistic effect being more pronounced in air and at lower EVA:biomass ratios. Higher temperature, lower ER and P/B conditions favour hydrogen production with less tar. The ANOVA data suggests that the interdependencies between T-ER and ER-P/B are effective in this system. The optimisation results indicate that the optimal condition to maximise favourable gas components and minimise tar production is at 790 °C, 0.17 ER, and 25 P/B ratio. Even at low blending ratios, adding EVA enhances tar quality by reducing the number of oxygenated compounds in the tar and by increasing the volume of hydrocarbons. The findings suggest that adding biomass to EVA prior to gasification is a promising approach that will assist with managing disposed solar cells with capacity to value-add to the waste material.