Microwave assisted solketal production by acetalization of glycerol – A byproduct of biodiesel production using functionalized cellulose catalyst

The objective of this study was to prepare carbonaceous catalysts. Taking cellulose as the starting material, functionalization with sulphuric acid was done using 1:10 w / v ratio under one pot hydrothermal treatment at 80 °C. The catalyst was extensively characterized with BET, XPS, TGA, SEM, FT-IR, XRD etc. The synthesized C-SO 3 H catalyst had a surface area of 447 m 2 g −1 , pore radius of 30.020 Å and pore volume of 0.157 cc g −1 . The total acidity of the catalyst was 4.56 mmol g −1 and sulphonic acid density was 1.31 mmol g −1 . It was used in acetalization of glycerol under microwave irradiation. Under the optimized reaction conditions of 1:5 M ratio of glycerol and acetone, catalyst loading of 7 wt% at 70 °C in 10 min, the glycerol to solketal conversion was found to be 97.1%. The product was characterized with FT-IR, NMR, GC–MS that confirmed the successful synthesis of solketal. The catalyst showed excellent reusability giving 82.1% conversion at the 5th reaction cycle.