Acid catalysts have a lower reaction rate than alkali catalysts. Acid catalysts’
transesterification is 4000 times lesser than the alkali-catalyzed reaction (Huang et al.
2010). Enzyme catalyst is more costly than a base catalyst. Hence, base catalysts are
favored in the industrial procedure (Fan et al. 2010).
Various types of catalysts utilized for transesterification are enzymes, anion
exchange resins, alkaline earth metal combinations, and titanium silicates.
Diverse forms of transesterification methods are exposed in Fig. 1.6 (Hassan and
Abul Kalam 2013).
The free fatty acid matters cause noteworthy results on the transesterification of
glycerides with alcohol by means of a catalyst (Johanes Berchmans and Hirata
2008).
As stated earlier, the existence of great free fatty acids in the feedstocks renders its
processing difficult, because the reaction of saponification by alkaline catalysts leads
to soap formation (Fig. 1.7) (Atadashi et al. 2012).
The detergents encourage the creation of steady emulsions that avoid separation
of the biodiesel from the glycerin through processing and reduced biodiesel yields
Fig. 1.5 Transesterification of triglycerides (Atadashi et al. 2012; Hassan and Abul Kalam 2013)
1 Biofuel Production Technologies, Comparing the Biofuels and Fossil Fuels
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