(183f) Synergetic Effects of Co-Pyrolysis of Hdpe and Various Biomass Feedstocks By ZSM-5 and MCM-41/ZSM-5 Composites

The production of renewable fuels has become necessary as fossil fuels continue to deplete past the point of no return. Catalytic fast pyrolysis (CFP) of biomass to high-value liquid fuels has emerged as a promising solution. However, CFP is hindered by the low hydrogen to carbon (< 1 H:C) effective ratio of biomass, which results in high coke and low oil yields. Co-pyrolysis of biomass and hydrogen-rich materials, such as plastic, can increase the overall H:C ratio, thereby increasing oil yields. Over 4.8 million tons of plastics have entered the ocean since 2010, making co-pyrolysis of waste plastic and biomass an effective waste utilization method while increasing pyrolysis effectiveness.¹

In this work, catalytic fast co-pyrolysis using a Py-GC/MS system was performed on real feedstocks (miscanthus × giganteus and food waste) and model compounds (cellulose, xylan, lignin and protein) mixed with high density polyethylene (HDPE) to elucidate the role of feedstock composition on oil yield in co-pyrolysis with ZSM-5 and composite MCM-41/ZSM-5 catalysts.

Results presented in figure 1 show the synergetic effect of HDPE in co-pyrolysis with miscanthus. The overall liquid and major liquid product class yields are increased at all mixing ratios. Notably, the phenol content of co-pyrolysis oils is lower than that of pure biomass corresponding to a lower oxygen content. The optimum mixing ratio of HDPE to miscanthus was found to be 1:3 corresponding to the largest increase in total liquid carbon yield of 12%. This work aims to show the influence of biomass molecular makeup on performance in co-pyrolysis with HDPE in order to effectively tailor feedstock composition for greater yields.

References

(1) Jambeck, J. R.; Geyer, R.; Wilcox, C.; Siegler, T. R.; Perryman, M.; Andrady, A.; Narayan, R.; Law, K. L. Plastic Waste Inputs from Land into the Ocean. Science (80-.). 2015, 347 (6223). https://doi.org/10.1126/science.1260352.