Development of an onboard waste-to-energy process for disposing marine plastics debris

This study aims to design the onboard waste-to-energy process to dispose waste plastic debris floating in the ocean. Collected marine debris undergoes pretreatment such as freezing and pulverization process. The pretreated plastic waste is transformed into hydrogen through plasma gasification, separation and purification which finally produces electricity by fuel-cell system. The hydrogen separation and purification process consist of water gas shift reaction and pressure swing adsorption process. Lab-scale experiments for the separation and purification process were carried out as a preliminary study prior to designing a practical scale integrated system. For low-temperature water gas shift, Cu–Zn–Al catalyst calcined under nitrogen atmosphere outperformed typical commercial catalysts. Process simulations indicate the need of additional apparatus such as heat exchanger, dehumidifier, and compressor for practical operation of the combined waste-to-energy process. Practical operation window based on the deviation between the ideal performance obtained from simulations and the measured performance from experiments was discussed.