Synthesis and characterization of sulfonated carbon catalysts derived from biomass waste and its evaluation in glycerol acetylation

• Published in: Biomass conversion and biorefinery 2022-06, Vol.12 (6), p.2045-2060
• Main Authors: Nda-Umar, Usman Idris, Ramli, Irmawati, Muhamad, Ernee Noryana, Taufiq-Yap, Yun Hin, Azri, Norsahida
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetylation; Biomass; Biotechnology; Carbon; Catalysts; Catalytic activity; Chemical synthesis; Energy; Glycerol; Liquid phases; Original Article; Reaction time; Renewable and Green Energy; Selectivity; Sulfuric acid; Synergistic effect; Titration; Triacetin
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-020-00784-0

Sulfonated carbon catalysts were synthesized from palm kernel shell biomass using direct, chemical and template methods of carbonization under CO 2 environment at 400 and 800 °C respectively and subsequently functionalized with concentrated sulfuric acid. The precursor material and the synthesized catalysts were characterized by proximate analysis, CHNS, XRD, FTIR, TPD, TGA, SEM, N 2 adsorption isotherm, BET surface area, and acid-base titration. The synthesized acid catalysts were evaluated in glycerol acetylation with acetic acid (molar ratio 1:6) in a batch liquid phase reaction under atmospheric pressure at 120 °C, 450 rpm for 1 h, 3 h, and 5 h respectively. The performance was compared with commercial Amberlyst-15 catalysts and homogeneous concentrated sulfuric acid. Of all the synthesized catalysts, the catalyst obtained from the template method carbonized at 800 °C showed the highest selectivity to triacetin (58.9%) with over 97% glycerol conversion within a 3-h reaction time. The selectivity to monoacetin and diacetin was 5.8 and 32.2% respectively. The catalytic activity of the catalyst was attributed to the synergistic effect of good physicochemical characteristics including textural properties and high acidic site density.