Oxy-hydrogen, solar and wind assisted hydrogen ([formula omitted]) recovery from municipal plastic waste (MPW) and saltwater electrolysis for better environmental systems and ocean cleanup

Abstract

The pyrolysis of plastic waste and the electrolysis of saltwater is a promising route to carbon neutrality in ocean cleanup and plastic waste management. Therefore, a solar and wind assisted H2-fuelled fast pyrolysis of MPW (municipal plastic waste) and electrolysis of desalinated saline were developed. The combined system uses an oxy-hydrogen furnace for thermal decomposition of MPW feed, CO2 as an inert reaction medium and both solar and wind energy systems to operate the electrical units. The deionised H2O feed to the electrolyser cell was produced from saltwater using the recovered heat from the fast pyrolyser unit. The process CO2 was captured and reused for soil improvement as current waste-to-energy routes of MPW recycling emit 695,850 tonnes of CO2. 2.65 kg/hrH2 fuel in an O2 environment was utilised to meet the decomposer operating temperature and heat duty which is approximately 29 % of the produced H2. Instability associated with bio-oil was prevented by using fast pyrolysis which release more volatiles. Compared to the related studies, this investigated work achieved the highest gas and carbon yields. Thermal NO < 0.1 ppm was recorded. The developed system is expected to reach ≥70 % energy efficiency and a sales price of < $3.89/kgH2.