Effect of Preparation Conditions on Structure and Activity of Sodium-Impregnated Oyster Shell Catalysts for Transesterification

Abstract

The catalyst preparation technique plays a significant role in its activity and durability. The present research investigated sodium hydroxide and sodium chloride as the precursor chemicals for impregnation on waste oyster shells that were tested as heterogeneous base catalysts for transesterification of soybean oil. Effects of precursor concentration and calcination temperature on the surface structure and the activity of the catalysts were studied via the one-factor-at-a-time method. The optimal impregnation concentrations of sodium hydroxide and sodium chloride were determined to be 6 mol/L and 2.43 mol/L, respectively. The optimal calcination temperature was determined to be 800 • C for both sodium hydroxide and sodium chloride-impregnated catalysts. Analyses of the catalysts via X-ray Diffraction and X-ray photoelectron spectroscopy indicated that different active species were formed on the surface depending on the calcination temperature. Results obtained from this study could be used to fine-tune the procedure for the synthesis of transesterification catalysts from aquatic animal shells.

Review of shell waste reutilization to promote sustainable shellfish aquaculture

“…The calcined oyster shells were impregnated with sodium hydroxide to obtain an alkaline catalyst, which increased the biodiesel yield from 71% in the control group to 87% 71 …”

“…The calcined oyster shells were impregnated with sodium hydroxide to obtain an alkaline catalyst, which increased the biodiesel yield from 71% in the control group to 87%. 71 The calcined shell powder generated sodium peroxide to significantly enhance the activity of the alkaline catalyst. When the calcined mussel shell powder was impregnated with KCl solution, and used as a catalyst in the production of biodiesel from waste food oil, a maximum yield of 97% was achieved.…”

Key Insights, Tools, and Future Prospects on Oyster Shell End-of-Life: A Critical Analysis of Sustainable Solutions

“…CNOS is potentially attractive for catalysis or cocatalysis in processes that require basic media, a typical case being the transesterification of soybean oil. − Very recently, CNOS nanoparticles were employed as a catalyst for the preparation of 1,8-dioxo-octahydroxanthenes via the one-pot condensation of 5,5-dimethylcyclohexane-1,3-dione or dimedone with various aldehydes under solvent-free conditions . Chemical stability and reusability of CNOS catalyst are among parameters to be investigated.…”