Enzymatic transesterification of olive oil and its precursors

A comprehensive review on nanocatalysts and nanobiocatalysts for biodiesel production in Indonesia, Malaysia, Brazil and USA

Biodiesel is an alternative to fossil-derived diesel with similar properties and several environmental benefits. Biodiesel production using conventional catalysts such as homogeneous, heterogeneous, or enzymatic catalysts faces a problem regarding catalysts deactivation after repeated reaction cycles. Heterogeneous nanocatalysts and nanobiocatalysts (enzymes) have shown better advantages due to higher activity, recyclability, larger surface area, and improved active sites. Despite a large number of studies on this subject, there are still challenges regarding its stability, recyclability, and scale-up processes for biodiesel production. Therefore, the purpose of this study is to review current modifications and role of nanocatalysts and nanobiocatalysts and also to observe effect of various parameters on biodiesel production. Nanocatalysts and nanobiocatalysts demonstrate long-term stability due to strong Brønsted-Lewis acidity, larger active spots and better accessibility leading to enhancethe biodiesel production. Incorporation of metal supporting positively contributes to shorten the reaction time and enhance the longer reusability. Furthermore, proper operating parameters play a vital role to optimize the biodiesel productivity in the commercial scale process due to higher conversion, yield and selectivity with the lower process cost. This article also analyses the relationship between different types of feedstocks towards the quality and quantity of biodiesel production. Crude palm oil is convinced as the most prospective and promising feedstock due to massive production, low cost, and easily available. It also evaluates key factors and technologies for biodiesel production in Indonesia, Malaysia, Brazil, and the USA as the biggest biodiesel production supply.

Optimizing the catalytic activities of methanol and thermotolerant Kocuria flava lipases for biodiesel production from cooking oil wastes

In this study, two highly thermotolerant and methanol-tolerant lipase-producing bacteria were isolated from cooking oil and they exhibited a high number of catalytic lipase activities recording 18.65 ± 0.68 U/mL and 13.14 ± 0.03 U/mL, respectively. Bacterial isolates were identified according to phenotypic and genotypic 16S rRNA characterization as Kocuria flava ASU5 (MT919305) and Bacillus circulans ASU11 (MT919306). Lipases produced from Kocuria flava ASU5 showed the highest methanol tolerance, recording 98.4% relative activity as well as exhibited high thermostability and alkaline stability. Under the optimum conditions obtained from 3D plots of response surface methodology design, the Kocuria flava ASU5 biocatalyst exhibited an 83.08% yield of biodiesel at optimized reaction variables of, 60 ○C, pH value 8 and 1:2 oil/alcohol molar ratios in the reaction mixture. As well as, the obtained results showed the interactions of temperature/methanol were significant effects, whereas this was not noted in the case of temperature/pH and pH/methanol interactions. The obtained amount of biodiesel from cooking oil was 83.08%, which was analyzed by a GC/Ms profile. The produced biodiesel was confirmed by Fourier-transform infrared spectroscopy (FTIR) approaches showing an absorption band at 1743 cm-1, which is recognized for its absorption in the carbonyl group (C=O) which is characteristic of ester absorption. The energy content generated from biodiesel synthesized was estimated as 12,628.5 kJ/mol. Consequently, Kocuria flava MT919305 may provide promising thermostable, methanol-tolerant lipases, which may improve the economic feasibility and biotechnology of enzyme biocatalysis in the synthesis of value-added green chemicals.