Catalytic co-Pyrolysis of residual biomass and waste plastics to produce drop-in alternative hydrocarbons

This study looked at the potential synergy of co-pyrolysis of residual lignocellulosic biomass in the form of olive stone with low-density polyethylene in the absence/ presence of solid acid catalyst in a bench scale continuous bubbling fluidised bed reactor. Despite the catalyst lowering the pyrolytic oil yield, there was significant transition in the class of hydrocarbon derivatives formed with catalytic co-pyrolysis yielding much more deoxygenated hydrocarbons in contrast to the product class from the inert sand bed. ?-alumina performed much better improving the H/C molar ratio of bio-oil by ~20% over the inert bed co-pyrolysis experiment, both the ?-alumina and HZSM-5 catalyst significantly lowered the O/C molar ratio of bio oil recovered. The product stream from both catalysts was relatively high in polycyclic aromatic hydrocarbons (PAHs)due to the strong acid catalysed reactions which promotes strong aromatisation.