| Summary: | Organosulfonic acid-functionalized biomass-derived carbon catalysts were developed using different aryl
and alkyl sulfonating reagents at low concentrations. The catalysts were characterized using advanced analytical techniques and evaluated in glycerol acetylation in a batch reflux reactor. Results indicated that the
catalyst obtained from the functionalization of palm kernel shell with ethanesulfonic acid (ESA) exhibited
better performance in terms of glycerol conversion and triacetin selectivity. Response surface methodology
(RSM) was used to develop empirical models to optimize the reaction conditions and subsequently validated.
Average values of 99.03§0.14% GC, 6.91§0.56, 54.86§0.42, and 37.73§0.21% selectivity to monoacetin, diacetin and triacetin, respectively were achieved at the optimum conditions of temperature 120§2 °C, glycerol
to acetic acid mole ratio of 1:8, catalyst load of 0.69 g and reaction time of 3 h. The models were statistically
analyzed and exhibited a good fit with agreement between the predicted and the experimental data, the
determination coefficient (R2
) > 0.9500 and adequate signal-to-noise ratio >4. The effects of the reaction variables and their interaction were further explained using the models and the surface response plots. On the
reusability test, the catalyst exhibited excellent performance in glycerol conversion and diacetin selectivity
for the five reaction cycles but was inferior in the selectivity to triacetin, stabilizes only after the first reaction
cycle at a reduced level, due to leaching of the acidic sites.
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