Work

Pressurized Torrefaction: Physiochemical characterization of torrefied miscanthus and beechwood

Year: 2025

Type: article

Abstract: Pressurized torrefaction (PT) is proposed as an effective pretreatment technology for enhancing the properties of lignocellulosic biogenic residues. This study therefore investigated the physiochemical properties of miscanthus and beechwood torrefied in a 600 cm³ batch autoclave reactor under varying conditions: temperatures of 250°C, pressures of 1.0 MPa, 1.4 MPa, and 1.8 MPa, and residence times of 30 and 60 minutes. Performance metrics, including reductions in volatile matter, oxygen content, and enhancements in higher heating value (HHV), as well as carbon enrichment and mass/energy yields, were evaluated. Results indicated a reduction in volatile matter by 10.9 - 32.5%, carbon enrichment by 12.4 - 33.4%, and oxygen removal by 13.9–37.5% for both miscanthus and beechwood. The HHV of the torrefied biomass reached 25.6 MJ/kg for miscanthus and 26.2 MJ/kg for beechwood, compared to 18.9 MJ/kg and 19.8 MJ/kg, respectively, for the raw biomass. Pressure was found to influence chemical energy preservation. Additionally, aromaticity and crystallinity of the torrefied biomass decreased and increased, respectively, with higher pressure and longer residence times. This study concludes that pressurized torrefaction is a promising method for upgrading biomass, enhancing its suitability for advanced thermochemical processes and sustainable energy production.

Source: Energy

DOI: 10.1016/j.energy.2025.137045

Authors: Omar Dacres, Marina Suárez Gómez, Sebastian Fendt

Institution: Technical University of Munich

Language: English

Topic: Thermochemical Biomass Conversion Processes

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Responsible consumption and production, Climate action

Open Access status: hybrid

Estimated APC paid: $4,260