Student researchers at Northeastern University have designed an apparatus to convert plastic waste into clean energy while minimizing the release of harmful emissions. Self-sustainability is the key to the double-tank combustor design. Plastic waste is first processed in an upper tank through pyrolysis, which converts solid plastic into gas. Next, the gas flows to a lower tank, where it is burned with oxidants to generate heat and steam. The heat sustains the combustor while the steam can be used to generate electric power.