(2026) Process Safety and Environmental Protection_CO₂-assisted thermochemical platform for simultaneous production of supercapacitor electrode and high value fuels from pine sawdust

Lee S.; Cho S.-H.; Kwon K.; Jung S.; Kwon E.E.

(Institution of Chemical Engineers) Process Safety and Environmental Protection ISSN: 9575820 Vol.206 Issue. Article No.108259 DOI: 10.1016/j.psep.2025.108259

The upcycling of lignocellulosic biomass waste has received particular attention in terms of sustainable waste management and the recovery of value-added products. However, rigid and complicated lignin-rich biomass is rarely used because of its limited applications. Here, we constructed a strategic pyrolysis platform for the recovery of value-added three-phase products: energy storage materials, biofuels, and energy-intensive gas. Pine sawdust (PSD) pyrolysis produced highly porous biochar (surface area: 737 m² g⁻¹) when CO₂ was introduced as a flow gas without further activation processes. The PSD biochar electrode showed a large specific capacitance (337.54 F g⁻¹) compared to other biochar activated by vigorous chemical treatment. The current products of PSD pyrolysis are bio-oil and pyrolysis gas, which can be used as biofuels and platform chemicals. The heating value of bio-oils was > 24 MJ kg⁻¹ without further upgrading. The major gaseous products are CH₄ and syngas (H₂/CO), which can serve as gaseous fuels or as feedstocks for fine chemical synthesis. The estimated energy yield from the gaseous products was 11.05 MJ kg(PSD)⁻¹ under the CO₂ condition, which is 4.35 times higher than N₂ condition. Here, the pyrolysis of lignocellulosic biomass waste under CO₂ produced porous biochar with acceptable electrochemical performance for use as a supercapacitor electrode, and value-added oil and gaseous fuels were obtained. Therefore, a thermochemical platform with CO₂ can be used to produce energy storage materials, beneficial biofuels, and chemicals without further treatment. © 2025 The Institution of Chemical Engineers

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No. RS-2023\u201300219667 ).