Application of a BPH zeolite for the transesterification of glycerol to glycerol carbonate: effect of morphology, cation type and reaction conditions

• Published in: Inorganic chemistry frontiers Vol. 1; no. 2; pp. 579 - 59
• Main Authors: Kosawatthanakun, Siriporn, Clatworthy, Edwin B, Ghojavand, Sajjad, Sosa, Narongrit, Wittayakun, Jatuporn, Mintova, Svetlana
• Format: Journal Article
• Language: English
• Published: London Royal Society of Chemistry 17.01.2023
• Subjects: Aluminum; Basicity; Biodiesel fuels; Catalysts; Catalytic activity; Cesium; Glycerol; Hydrothermal treatment; Inorganic chemistry; Ion exchange; Morphology; Nanostructure; Pore size; Selectivity; Silicon; Thermodynamic properties; Transesterification; Zeolites
• ISSN: 2052-1553; 2052-1545; 2052-1553
• DOI: 10.1039/d2qi02023h

Valorization of glycerol (Gly) to high-value chemicals is the key to unlocking economic and sustainable biodiesel production. The transesterification of Gly with dimethyl carbonate (DMC) to glycerol carbonate (GC) requires a catalyst with high basicity and uniform pore size for high product selectivity. BPH-type zeolite (Linde Q) nanosheets are promising catalysts for overcoming diffusion transport limitations inside the pore network and inhibiting the formation of glycidol as a side product. As-prepared BPH nanosheets (nano-sized CsBPH_AP, 192 nm size) and micron-sized BPH (micron-sized KBPH_AP, 600 nm size) were prepared by hydrothermal treatment with different Si/Al ratios. With a morphology-dependent reaction, the nano-sized CsBPH_AP demonstrates superior performance in the transesterification of Gly to GC as compared to micron-sized KBPH_AP. Ion-exchange of the nano-sized CsBPH_AP and micron-sized BPH_AP, with potassium and cesium precursors respectively, to afford nano-sized K-CsBPH_IE and micron-sized Cs-KBPH_IE resulted in similar thermal properties but different basicity and catalytic activity compared to the parent samples; higher basicity resulted in better catalytic performance. The nano-sized CsBPH_AP with a catalyst loading of 6 wt% shows good catalytic performance over four runs under optimized reaction conditions at 120 °C for 3 h and the Gly : DMC molar ratio of 1 : 5. This study reveals the crucial effect of catalyst morphology and size on the conversion of Gly to GC. Valorization of glycerol (Gly) to high-value chemicals is the key to unlocking economic and sustainable biodiesel production.