Prediction of pyrolyzate yields by response surface methodology: A case study of cellulose and polyethylene co-pyrolysis

There are numerous combinations of biomass, plastic, and co-pyrolysis conditions. The presence of synergies, which make pyrolyzate distribution more complex, has been supported by research. In this study, the potential of response surface methodology (RSM) to predict the pyrolyzate yields affected by synergies during co-pyrolysis (500–700 °C) of cellulose and polyethylene was investigated, beyond gas, oil, and char yields. The results indicated that co-pyrolysis promoted liquid and C_5–28 hydrocarbon production with increasing temperature. The quadratic model could predict the total gas, CO, CO₂, and liquid yields, including the synergy. The cubic model could predict the levoglucosan and C_5–28 hydrocarbon yields due to various synergies under different conditions. The linear model was suitable for the char yield distribution without interaction. Thus, this study reveals that RSM has a significant potential to predict pyrolyzate yields, enabling co-pyrolysis condition setting to maximize the desired product recovery with the fewest experiments.