INFORM November/December 2025

inform November/December 2025, Vol. 36 (10) • 33

a CuAl catalyst was evaluated in the gas phase dehydration of glyc erol, focusing on the influence of temperature (200–300 °C), cata lyst weight to glycerol mass flow ratio (10–50 g Catalyst min g Glycerol −1 ), and carrier gas to liquid ratio (200–600 m 3 Gas STP m 3 Liquid −1 ). Both pure and biodiesel-derived refined crude glycerol were used as feed stock. Long-term stability experiments assessed the evolution of catalytic activity and physicochemical properties over time. A great activity was obtained under conditions of 250 °C, 30 g Catalyst min g Glycerol −1 , and 400 m 3 Gas STP m 3 Liquid −1 with pure glycerol after a time-on-stream (TOS) of 2 h (95.1 % glycerol conversion and 564 mg Acetol g Glycerol −1 ). Stability studies provided good catalytic results after a TOS of 52 h using pure glycerol (72 % glycerol conversion and 266 mg Acetol g Glycerol −1 ) and demonstrated that coke deposi tion was responsible for catalyst deactivation. The use of refined crude glycerol proved to be highly effective in the first hours of the reaction (98.7 % glycerol conversion and 570 mg Acetol g Glycerol −1 for a TOS of 2 h), however, rapid deactivation was observed due to solids deposition. This catalytic route highlights the feasibility of valorization of biomass residues for producing renewable acetol, a promising precursor for sustainable aviation fuel (SAF). Electrolysis of valorization of industrially sourced crude glycerol Gaines, R.N., et al. , ACS Sustainable Chemistry & Engineering , 13, 33, 2025. https://doi.org/10.1021/acssuschemeng.5c03028 Valorization of waste (crude) glycerol could enhance sustain ability of chemical manufacturing and the economics of biodiesel production. Crude glycerol is of low value, and is typically a mixture of glycerol, methanol, water, sodium hydroxide, and residual impuri ties. This study disentangles the influences of methanol and triglycer ide impurities on the electrolytic oxidation of industrially sourced waste glycerol. Data from industrial biodiesel producers uncovered two predominant waste glycerol formulations: methanol-rich and methanol-lean. Electrolysis using synthetic equivalents of these for mulations over a nickel catalyst in a flow electrolyzer revealed that performance losses of up to 90% can be avoided in the presence of ≥0.5 M methanol. At lower concentrations of methanol, use of a dynamic reactor operation protocol mitigated performance losses. The combination of these results enabled stable multihour electro lytic production of the valuable chemical formate from industrially sourced waste glycerol. These findings provide guidance toward fea sible operating conditions and process parameters for the further development of crude glycerol electrolysis in industrial practice. Multidimensional utilization of kraft lignin: Upgrading glycerol to sustainable fuel additives using lignin-derived benzaldehyde over lignin-based acid catalyst Zhang, C., et al. , ACS Sustainable Chemistry & Engineering , 13, 18, 2025. https://doi.org/10.1021/acssuschemeng.5c02247 This study aims to explore a lignin-based catalyst for the green synthesis of sustainable fuel additive using lignin-derived benzal dehyde and glycerol, byproducts from the paper industry and bio diesel preparation, respectively. This sustainable fuel additive can

be refilled into biodiesel to improve the carbon atom economy, pro moting resource efficiency and environmental sustainability. Kraft lignin was modified with phosphoric acid and sulfuric acid to pre pare solid acid catalysts KL-HP-SO 3 H. A series of characterization techniques showed that phosphorylation can markedly enhance the specific surface area, while sulfonation can notably increase the acid sites and acid strength. The synergistic physical–chemical effect of phosphorylation and sulfonation collectively enhances the activity of the KL-HP-SO 3 H catalyst. In addition, ball milling and thermal catalysis were compared and analyzed in this study. The results show that the ball milling technology offers an advantage: it achieves a high product yield within only 15 min. The ball milling process consumes less energy than the hydrothermal reactor (21.3 vs 493.8 kWh·mol –1 ). From a long-term investment perspective, the ball milling process is economically superior. This study contrib utes an efficient catalyst strategy to green chemical synthesis while providing multifunctional utilization of lignin.

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Ignacio Vieitez is a research professor at the Universdad de la República in Montevideo, Uruguay. He studies green extraction processes to isolate bioactive compounds and determines their potential benefits as food ingredients.

Natural antioxidants play a key role in stabilizing industrial oil prod ucts, including edible oils, biodiesel, lubricants, and cosmetics. Compounds such as tocopherols, carotenoids, phenolic acids, and flavonoids—often sourced from agri-food by-products like grape seeds, olive pomace, and coffee silverskin—effectively inhibit lipid oxidation, extending shelf-life and preserving functional quality. The growing demand for clean-label and sustainable solutions has accelerated the replacement of synthetic antioxidants (e.g., BHA, BHT) with natural extracts. In addition to safety and consumer acceptance, these bioactive compounds frequently exhibit syner gistic effects when combined, making them attractive for diverse industrial applications. Green extraction of plant antioxidants: Supercritical methods and industrial applications—a review Tan, H.L., et al. , Food and Humanity , In Press, 100787, 2025. https://doi.org/10.1016/j.foohum.2025.100787 Plant-derived antioxidants are valuable for their health benefits and roles as natural preservatives in foods, cosmetics, and pharmaceu ticals. Green extraction methods have gained prominence as sustain able, efficient, and safe alternatives to conventional solvent-intensive techniques. Supercritical fluid extraction (SFE), particularly with CO₂, has emerged as an important green technology for recovering antioxi dants from plant materials. This review provides a comprehensive over view of SFE principles and advantages, compares SFE with traditional