Functional use of carbon dioxide for the sustainable valorization of orange peel in the pyrolysis process

Jung Hun KIM, Taewoo LEE, Yiu Fai TSANG, Deok Hyun MOON, Jechan LEE, Eilhann E. KWAN

Research output: Contribution to journalArticlespeer-review


Although biomass is carbon-neutral, its use as a primary feedstock faces challenges arising from inconsistent supply chains. Therefore, it becomes crucial to explore alternatives with reliable availability. This study proposes a strategic approach for the thermochemical valorization of food processing waste, which is abundantly generated at single sites within large-scale processing plants. As a model biomass waste from the food industry, orange peel waste was particularly chosen considering its substantial consumption. To impart sustainability to the pyrolysis system, CO₂, a key greenhouse gas, was introduced. As such, this study highlights elucidating the functionality of CO₂ as a reactive feedstock. Specifically, CO₂ has the potential to react with volatile pyrolysates evolved from orange peel waste, leading to CO formation at ≥490 °C. The formation of chemical constituents, encompassing acids, ketones, furans, phenols, and aromatics, simultaneously decreased by 15.1 area% in the presence of CO₂. To activate the efficacy of CO₂ at the broader temperature spectrum, supplementary measures, such as an additional heating element (700 °C) and a nickel-based catalyst (Ni/Al₂O₃), were implemented. These configurations promote thermal cracking of the volatiles and their reaction kinetics with CO₂, representing an opportunity for enhanced carbon utilization in the form of CO. Finally, the integrated process of CO₂-assisted catalytic pyrolysis and water-gas shift reaction was proposed. A potential revenue when maximizing the productivity of H₂ was estimated as 2.62 billion USD, equivalent to 1.11 times higher than the results from the inert (N₂) environment. Therefore, utilizing CO₂ in the pyrolysis system creates a promising approach for enhancing the sustainability of the thermochemical valorization platform while maximizing carbon utilization in the form of CO. Copyright © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Original languageEnglish
Article number173701
JournalScience of the Total Environment
Early online dateJun 2024
Publication statusE-pub ahead of print - Jun 2024


Kim, J.-H., Lee, T., Tsang, Y. F., Moon, D. H., Lee, J., & Kwon, E. E. (2024). Functional use of carbon dioxide for the sustainable valorization of orange peel in the pyrolysis process. Science of the Total Environment, 941, Article 173701.


  • Circular economy
  • Waste valorization
  • Food processing waste
  • Thermochemical process
  • CO2 utilization


Dive into the research topics of 'Functional use of carbon dioxide for the sustainable valorization of orange peel in the pyrolysis process'. Together they form a unique fingerprint.