Sumin Lee  Dongho Choi  Jaewon Lee  Hyungtae Cho

Vol. 31,  No. 4, pp. 319-329, Dec.  2025
10.7464/ksct.2025.31.4.319

Waste plastics Water-Gas Shift (WGS) reaction Carbon dioxide capture and storage (CCS) Hydrogen Techno- economic assessment

PDF

With the rapid increase in plastic production, the generation of plastic waste has risen. Conventional disposal methods, such as landfills and incineration, have negative environmental impacts due to the emission of pollutants. Therefore, it is important to seek an environmentally neutral method for plastic waste disposal. As an effort to achieve this, this work proposes a pyrolysis-based process for plastic waste treatment that simultaneously enables sustainable hydrogen production. In the proposed process, waste PET is converted into pyrolysis gas, oil, and char through CO2-assisted pyrolysis. The carbon monoxide contained in the pyrolysis gas is utilized for hydrogen production via the water-gas shift (WGS) reaction. Two integrated configurations were investigated: (1) thermal energy recovery from byproduct combustion to generate steam, and (2) electricity generation through a steam Rankine cycle. The annual hydrogen production reached approximately 248 tons yr–1. A techno-economic assessment revealed that integrating steam recovery leads to a 42% lower levelized cost of hydrogen compared to the electricity generation system. Furthermore, the proposed process utilizes the CO2 generated within the process itself. Moreover, dependence on external energy was effectively reduced by integrating an energy recovery system. These findings suggest that the proposed process is a promising approach for simultaneously treating waste PET and achieving value-added hydrogen production.