Yuming Zhang

This integrative critical review examines how biomass and bioenergy can contribute to energy diversification while accounting for constraints related to climate mitigation, energy security, resource availability, and technology readiness. The review combines a targeted literature synthesis with expert-informed insights from the international seminar Energy Transition and Biofuels held at the Federal University of Itajubá in October 2025. The seminar and COP30-related discussions were used as contextual and conceptual inputs, while peer-reviewed literature, policy documents, and technical reports provided the evidentiary basis for the analysis. The manuscript evaluates biomass and biofuels utilization, refinery integration, sustainable aviation fuels, biochar, BECCS, hydrogen synergies, life-cycle assessment, artificial intelligence, and logistics. The synthesis indicates that biomass is not a universal substitute for fossil fuels. Still, it has distinctive value in applications requiring renewable carbon, dispatchable energy, process heat, liquid fuels, carbon removal, and compatibility with existing infrastructure. The analysis also shows that these contributions are contingent on feedstock governance, land and water safeguards, logistics, fertilizer inputs, technology maturity, and verified life-cycle performance. The food–fuel discussion is therefore reframed as a context-specific problem of land-use, access, productivity, and governance rather than a simple competition between energy and food production. The study concludes that bioenergy can most credibly support the energy transition when deployed through differentiated pathways tailored to regional resources, sustainability constraints, and sector-specific decarbonization requirements.

Lactic acid, a key platform chemical derived from renewable glycerol (a major byproduct of biodiesel production), holds great potential for the sustainable synthesis of high‐value chemicals such as pyruvic acid. An efficient catalytic process for the oxidative dehydrogenation of glycerol‐derived lactic acid by metal oxides is studied. A series of metal oxides was prepared, and their performance in the aerobic conversion of lactic acid was evaluated. During the performance evaluation, a strong crystal phase effect of MoO ₃ was observed, with α ‐MoO ₃ (orthorhombic phase) and h‐MoO ₃ (hexagonal phase) exhibiting significant differences in catalytic activity and selectivity. Specifically, α ‐MoO ₃ showed a lactic acid conversion rate of only 52.3% and a pyruvic acid selectivity of 41.8%, while h‐MoO ₃ demonstrated superior catalytic performance. The optimal catalyst is h‐MoO ₃ , with a lactic acid conversion rate of 81.6% and a pyruvic acid selectivity of 63.7%. Furthermore, the catalysts were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and nitrogen adsorption. XRD and FTIR revealed the transformation from α ‐MoO ₃ to h‐MoO ₃ , while XPS demonstrated the influence of crystal phase on the catalyst's oxidative capability.

Agricultural biomass, including lignocellulosic residues and algal feedstocks, represents an abundant renewable resource with potential for sustainable energy production and environmental remediation. This review systematically explores the latest research on turning agricultural wastes into the agricultural circular economy via thermochemical conversion techniques. Biochar and hydrochar are two of the most frequently reported products, with applications that enhance crop yields by approximately 19.9–36.9% and contribute to soil improvement and pollutant remediation. Studies employing machine learning (ML), life cycle assessment (LCA), and techno-economic analysis (TEA) demonstrate the effectiveness of these approaches: ML-optimized biochar can reach specific surface areas up to 400.0 m2/g, immobilize heavy metals in soil with efficiencies over 90.0%, and remove contaminants from wastewater with efficiencies of 84.0–90.0% for heavy metals and 96.5% for organic pollutants. LCA and TEA results confirm notable environmental and economic benefits, including greenhouse gas emission reductions of 1.5 to 3.5 tCO2-eq per ton and production costs as low as $116.0/ton for biochar and $30.0/ton for hydrochar. These findings provide a solid foundation for integrating thermochemical conversion into circular economy frameworks and advancing agricultural sustainability.