Production of liquid hydrocarbons, carbon nanotubes and hydrogen rich gases from waste plastic in a multi-core reactor

•A novel multi-core reactor for producing CNTs from polyethylene waste is proposed.•A Vertical CVD unit containing multiple tray arrangement is used to synthesize CNTs.•Tray provides maximum catalyst loading and effective solid-gas contact.•CNTs of 6.033 g/30 g PE would yield over 1 g of Ni4Mo0.2MgO1 catalyst.•Multi-core reactor is highly effective to convert PE into carbon materials.

In this paper, a new reactor design based on central core heating system is presented that optimized the heat utilization and allowed compact reactor design. Conversion of waste plastic into liquid hydrocarbons, carbon nanotubes (CNTs) and hydrogen rich gases in a multi-core reactor was carried out. Thermal energy from central core was utilized for the pyrolysis of waste plastic and synthesis of CNTs. Pyrolysis of waste plastic was carried out in the outer chamber of reactor followed by catalytic decomposition of pyrolysis gases in the inner chamber. Tray arrangement inside CNT chamber provided maximum catalyst holdup and effective solid-gas contact. Reactor performance was studied at different pyrolysis temperatures and a fixed CNT synthesis temperature of 800 °C. Multi walled carbon nanotubes (MWCNTs) having 20-50 nm diameters and average wall thickness of 10 nm were synthesized with an yield of 6.03 g/30 g polyethylene.