Bio-oil production via catalytic microwave co-pyrolysis of lignin and low density polyethylene using zinc modified lignin-based char as a catalyst

•The application of lignin-based char as a catalyst.•Microwave co-pyrolysis of lignin and low density polyethylene for bio-oil production.•Optimization of the product distribution and value-added components of the bio-oil.•Enhancement of hydrocarbons in bio-oil and hydrogen in syn-gas.