What does this research mean for the field?

During the carbonization of woody biomass, copper additives favor solid carbon retention at moderate temperatures while titanium promotes decomposition, though the overall structural ordering of the resulting carbon is primarily determined by the final heating temperature rather than the specific metal additive. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

This research aims to understand how copper and titanium additives influence carbonization of biomass at different temperatures.

July 6, 2026Open Access

Thermal carbonization of woody biomass under inert atmosphere with temperature-dependent variation in the effects of Cu and Ti additives

THToshimitsu HataKyoto University SHSensho HonmaHokkaido Research Organization TWTakashi WatanabeKyoto University

Key Points

This research aims to understand how copper and titanium additives influence carbonization of biomass at different temperatures.
Examined effects of copper and titanium additives on carbonization of Todo fir wood flour at 500 °C and 800 °C under nitrogen.
Analyzed carbonization behavior using thermogravimetric-differential thermal analysis and characterized resulting char through elemental and microscopy techniques.
At 500 °C, copper enhanced carbon retention and stability, while titanium led to lower retention and more heterogeneous structures.
At 800 °C, both additives had limited impact on final char quality, with copper maintaining higher char retention and titanium promoting decomposition-related behavior.

Abstract

Background Carbonization of woody biomass under inert atmospheres is a practical route to producing functional carbon materials. However, carbon yield and microstructural development are strongly influenced by temperature and by the presence of metal additives. The temperature-dependent differences in the effects of such additives on carbonization behavior remain insufficiently understood. Methods The effects of copper and titanium additives were systematically examined during heat-induced carbonization of Todo fir ( Abies sachalinensis ) wood flour at 500 °C and 800 °C under nitrogen using controlled heating rates. Carbonization behavior was analyzed by thermogravimetric–differential thermal analysis. The resulting char was characterized by elemental analysis, scanning electron microscopy, and transmission electron microscopy. Results At 500 °C, copper addition was associated with the formation of partially layered turbostratic carbon structures with expanded interlayer spacing, suggesting possible stabilization of carbon frameworks with reduced bond cleavage. In contrast, titanium addition was associated with increased devolatilization and fragmentation, leading to lower carbon retention and more heterogeneous microstructures. At 800 °C, thermally stable, carbon-rich residues were obtained largely independent of heating rate, indicating that the final hold temperature was the primary factor influencing bulk carbon ordering. Under these conditions, copper was associated with higher char retention, whereas titanium was associated with enhanced interfacial reactions and decomposition-related behavior at carbon interfaces. Transmission electron microscopy showed that overall structural ordering was primarily determined by the final temperature rather than by the additive. These findings indicate temperature-dependent variation in additive effects, with copper favoring solid carbon retention at moderate temperatures and titanium showing stronger decomposition-related effects at elevated temperatures. Conclusions The results suggest distinct temperature-dependent differences in the effects of copper and titanium during biomass carbonization and provide a basis for considering additive selection and thermal design in controlling carbon yield and microstructure.

AIに質問

Bookmark

View Full Paper