Near-Critical CO₂-Assisted Liquefaction-Extraction of Biomass and Wastes to Fuels and Value-Added Products

Journal Article · 11 December 2023 · Journal of Energy Resources Technology

DOI: https://doi.org/10.1115/1.4063813 · OSTI ID:2282307

Burra, Kiran Raj Goud ^[1]; Sahin, Murat ^[1]; Zheng, Ying ^[2]; Gupta, Ashwani K. ^[1]

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1. University of Maryland, College Park, MD (United States)
2. Western University, London, ON (Canada)

With the growing need for sustainable carbon-neutral liquid fuels, low-grade feedstocks, such as lignocellulosic biomass, and municipal solid wastes offer sufficient potential via thermochemical conversion. But the existing thermochemical means are limited in feed flexibility and scalability and require significant processing (energy and costs) of the intermediates. Bio-oil/biocrude intermediate from fast pyrolysis and hydrothermal techniques is impeded by issues of stability and oxygen content, along with hydrotreating viability. To address these issues, we investigated a novel pathway of near-critical CO₂-assisted integrated liquefaction-extraction (NILE) technology in conceptual aspects for conversion of various biomass and municipal solid wastes into high-quality biocrude with high compatibility for co-hydrotreating with traditional fossil crude for liquid fuel needs in power and transportation sectors. Using supercritical CO₂ for dewatering wet feedstocks, for liquefaction, and extraction for lighter biocrude has produced biocrude with lower oxygen content by 50%, lowered metal content by 90%, stable viscosity, low acidity, and good aging stability compared to that produced from hydrothermal liquefaction along with higher hydrotreating and co-hydrotreating compatibility. Hydrotreating of the biocrude extract from supercritical CO₂ extraction also was feasible with no detected coke deposition, an oxygen content of 1%, and catalyst deactivation. Here, the validation and capabilities of the NILE concept urge for its further development to obtain sustainable liquid fuels with lower greenhouse gas emissions and costs.

• Research Organization: Univ. of Maryland, College Park, MD (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Bioenergy Technologies Office (BETO)
• Grant/Contract Number: EE0009757
• OSTI ID: 2282307
• Journal Information: Journal of Energy Resources Technology, Vol. 146, Issue 1; ISSN 0195-0738
• Publisher: ASMECopyright Statement
• Country of Publication: United States
• Language: English