In this report, we examined the value and challenges of gasification treatment as a possible alternative to the thermal recycling of waste plastics that cannot be recycled into feedstock. To do this, we designed a process involving the collection of 52,000 t of plastic containers and packaging per year and the production of 10,200 t of hydrogen, based on a vision of the city of Yokohama in 2030.
　First, a model was created in which waste plastic containers and packaging from each household are collected free of charge, processed into RPF, and transported to a gasification plant. Based on this model, the RPF cost is 10.4 yen/kg, and the CO₂ emissions from collection, processing, and transportation are 31.5 g CO₂/kg RPF. Next, the gasification process was designed. The energy conversion rate of this process is 62%. The hydrogen cost without CO₂ capture is 1.5 yen/MJ H₂, which is less competitive than the IEA’s hydrogen cost forecast for 2030 （1.6 yen/MJ H₂, by wind and solar power-based water electrolysis in the best location）. CO₂ emissions are 15 kg CO₂/kg H₂, more than four times the low-carbon hydrogen standard of 3.4 kg CO₂/kg H₂.
　Gasification of waste plastics is valuable because it enables the production of hydrogen without consuming new fossil resources. The cost of hydrogen could be improved by increasing the reuse rate of recovered heat and lowering the process temperature. However, all of the C in the feedstock is emitted as CO₂, well above the lowcarbon hydrogen standard.