Production of Triacetin by Microwave Assisted Esterification of Glycerol Using Activated Natural Zeolite

Abstract

Triacetin, an alternative biodiesel additive, was prepared by esterification of glycerol with acetic acid in the presence of chemically activated natural zeolite. The esterification was carried out in a small reaction flask under microwave irradiation. The catalyst was characterized for its morphology by SEM and its chemical composition by X-ray Diffraction (XRD). The Scanning Electron Microscopy (SEM) micrograph indicates improved surface area of the zeolite, while the XRD analysis shows an increase in Si/Al ratio from natural zeolite to 6.042 and its crystallinity value of 12.23%. The Fourier Transform Infra Red (FTIR) analysis obtained showed that microwave-heated samples have an esters group spectrum of triacetin at 1702 cm-1. The conversion value of glycerol was more than 95% at molar ratio of the reactants 1:9 and catalyst loading of 3%. The selectivities for monoacetin, diacetin and triacetin were 80.1%, 15.4%, and 4.5% at 60 minutes, and 43.0%, 48.6%, and 8.3% at 90 minutes. It shows that the conversion took place in consecutive steps and the use of microwave allows the reaction proceeding at milder condition. Copyright © 2019 BCREC Group. All rights reserved

Glycerol Acetylation Mediated by Thermally Hydrolysed Biosolids-Based Material

“…Furthermore, nanostructured sulphated zirconia led to higher yields of triacetin (up to 40%) with low catalyst loading [61]. A similar behaviour was also observed using acidic zeolites as reported by many authors [62][63][64]. Nonetheless, thermally-hydrolysed biosolids catalyst operates at lower temperature compared with heteropolyacidic catalytic systems reaching the same performances [65].…”

Optimization and Characterization of Mesoporous Sulfonated Carbon Catalyst and Its Application in Modeling and Optimization of Acetin Production

“…This result is promising when compared to earlier studies using acetic acid. The results of Okoye et al [ 18 ], Goscianska and Mailakal [ 22 ], Kakasaheb et al [ 23 ], and Marwan et al [ 24 ] exhibited triacetin selectivity of 43, 22, 15, and 8.3% with very high glycerol conversion (>95%) over different catalysts, which were lower under relatively similar reaction conditions than our earlier study. However, the triacetin selectivity reported by Rezayat and Ghaziaskar [ 19 ] and Liu et al [ 20 ] were much higher, as indicated earlier above, albeit under extreme conditions.…”

Influence of Heterogeneous Catalysts and Reaction Parameters on the Acetylation of Glycerol to Acetin: A Review

“…The reusability of heterogeneous catalysts aids their industrial applications irrespective of the type of reactor used [96]. A lot of heterogeneous catalysts have been used in glycerol acetylation, some of which include ion-exchange and functionalized resins [82,[97][98][99], zeolites and functionalized zeolites [73,100,101], heteropoly acids and supported heteropoly acids [93,[102][103][104]], metal oxides including mixed oxides and supported mixed oxides [105][106][107][108], montmorillonite (K-10 clay) and modified montmorillonite [87,91,109], mesoporous silica and functionalized silica [94,110,111], activated carbon and functionalized biomass-derived carbon [112][113][114]. However, it is important to indicate that the focus of most of the studies has been the effect of the type of catalyst, loading, and reusability.…”