Abstract
Biofuel-based combustion synthesis (BCS) is a promising low-carbon pathway for decarbonizing cement production, providing an alternative to the fossil-fuel-driven clinkering process typically conducted at ∼1450 °C. Understanding microscale combustion mechanisms is essential to efficiently transfer biofuel-generated heat to cement precursors for targeted phase formation. Unlike previous studies focusing on macro-scale parameters such as fuel content/type, porosity, and holding temperature, this work provides mechanistic insights into microscale combustion behavior, linking microstructural phenomena with macro-scale processing conditions to guide parameter optimization. In-operando microscale imaging was employed to examine combustion wave propagation, spatio-temporal temperature evolution, and microstructural transformations within reactive pellets. Two combustion modes were observed: surface combustion wave (SCW) and continuous combustion wave (CCW) near fuel ignition, and rapid volumetric heating followed by CCW at elevated input temperatures. Optimizing pellet properties—porosity (8–10 %) and fuel calorific value—resulted in reduced cracking and wave velocity dispersion (∼0.1–0.2 mm s−1), enabling more uniform wave propagation (0.5–0.75 mm s−1) and temperature stability (±25–50 °C) for sustained durations (∼1–2 min). These conditions allowed reliable synthesis of multiple cement phases. At 450 °C, ∼90–95 % limestone-to-lime conversion was achieved while maintaining calcination temperatures of ∼950 °C. At 700 °C, volumetric heating generated transient peaks of ∼1200 ± 100 °C, producing belite-rich cement (∼90 % C2S). At 800 °C, BCSA-type cement was formed (∼25 % ye'elimite, ∼50 % belite). At 900 °C, surface temperatures reached ∼1300 ± 100 °C, but limited dwell time restricted alite (C3S) formation (∼20 %), indicating further optimization is needed. These findings provide mechanistic insights and a foundation for scalable, energy-efficient, and low-carbon cement production via BCS.
Recommended Citation
S. Agrawal et al., "In-operando Imaging for Mechanistic Insights and Process Optimization in the Biofuel-driven Combustion Synthesis of Cement and Precursor Phases," Biomass and Bioenergy, vol. 208, article no. 108921, Elsevier, May 2026.
The definitive version is available at https://doi.org/10.1016/j.biombioe.2025.108921
Department(s)
Materials Science and Engineering
Second Department
Civil, Architectural and Environmental Engineering
Publication Status
Full Text Access
Keywords and Phrases
Cement; Combustion synthesis (BCS); Combustion wavefront; Digital high speed microscopic video recording (DHSMVR); In-operando imaging; Infrared (IR) thermography
International Standard Serial Number (ISSN)
1873-2909; 0961-9534
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2026 Elsevier, All rights reserved.
Publication Date
01 May 2026
Included in
Ceramic Materials Commons, Civil and Environmental Engineering Commons, Structural Materials Commons
Comments
Arizona State University, Grant DMR 2228782