Significant Seed Oil Feedstocks for Renewable Production of Biodiesel: A Review

A Novel Heterogeneous Superoxide Support-Coated Catalyst for Production of Biodiesel from Roasted and Unroasted Sinapis arvensis Seed Oil

Disadvantages of biodiesel include consumption of edible oils for fuel production, generation of wastewater and inability to recycle catalysts during homogenously catalyzed transesterification. The aim of the current study was to utilize low-cost, inedible oil extracted from Sinapis arvensis seeds to produce biodiesel using a novel nano-composite superoxide heterogeneous catalyst. Sodium superoxide (NaO2) was synthesized by reaction of sodium nitrate with hydrogen peroxide via spray pyrolysis, followed by coating onto a composite support material prepared from silicon dioxide, potassium ferricyanide and granite. The roasted (110 °C, 20 min) and unroasted S. arvensis seeds were subjected to high vacuum fractional distillation to afford fractions (F1, F2 and F3) that correlated to molecular weight. For example, F1 was enriched in palmitic acid (76–79%), F2 was enriched in oleic acid (69%) and F3 was enriched in erucic acid (61%). These fractions, as well as pure unroasted and roasted S. arvensis seed oils, were then transesterified using NaO2/SiO2/PFC/Granite to give biodiesel a maximum yield of 98.4% and 99.2%, respectively. In contrast, yields using immobilized lipase catalyst were considerably lower (78–85%). Fuel properties such as acid value, cetane number, density, iodine value, pour point, and saponification value were within the ranges specified in the American biodiesel standard, ASTM D6751, where applicable. These results indicated that the nano-composite catalyst was excellent for production of biodiesel from unroasted and roasted S. arvensis seed oil and its fractions.

Novel mutant camelina and jatropha as valuable feedstocks for biodiesel production

Novel mutant camelina has become a crop of interest inspired by its short growing season, low harvesting costs and high oil composition. Despite those advantages, limited research has been done on novel mutant lines to determine applicability for biodiesel production. Jatropha is an extremely hardy, frugal and high oil yielding plant species. The major aim of the present study was not only to compare biodiesel production from jatropha and camelina but was also to test the efficacy of camelina mutant lines (M6 progenies) as superior feedstock. The biodiesel yield from camelina oil and jatropha oil was 96% and 92%, respectively. The gas chromatographic analysis using flame ionization detector (GC-FID) showed that mutant camelina oil biodiesel sample contain major amount of oleic acid (46.54 wt%) followed by linolenic acid (20.41 wt%) and linoleic acid (16.55 wt%). Jatropha biodiesel found to contain major amount of oleic acid (45.03 wt%) followed by linoleic acid (25.07 wt%) and palmitic acid (19.31 wt%). The fuel properties of produced biodiesel were found in good agreement with EN14214 and ASTM D6751 standards. The mutant camelina lines biodiesel have shown comparatively better fuel properties than jatropha. It has shown low saponification value (120.87–149.35), high iodine value (130.2–157.9) and better cetane number (48.53–59.35) compared to jatropha biodiesel which have high saponification value (177.39–198.9), low iodine value (109.7–123.1) and lesser cetane number (47.76–51.26). The results of the present student of utilizing novel mutant camelina lines for biodiesel production are quite promising and are helpful in turning out the outcomes of the previous studies suggesting that C. sativa biodiesel presents serious drawbacks for biodiesel applications.

High Vacuum Fractional Distillation (HVFD) Approach for Quality and Performance Improvement of Azadirachta indica Biodiesel

Biodiesel offers an advantage only if it can be used as a direct replacement for ordinary diesel. There are many reasons to promote biodiesel. However, biodiesel cannot get wide acceptance until its drawbacks have been overcome including poor low temperature flow properties, variation in the quality of biodiesel produced from different feedstocks and fuel filter blocking. In the present study, a much cheaper and simpler method called high vacuum fractional distillation (HVFD) has been used as an alternative to produce high-quality refined biodiesel and to improve on the abovementioned drawbacks of biodiesel. The results of the present study showed that none of biodiesel sample produced from crude Azadirachta indica (neem) oil met standard biodiesel cetane number requirements. The high vacuum fractional distillation (HVFD) process improved the cetane number of produced biodiesels which ranged from 44–87.3. Similarly, biodiesel produced from fractionated Azadirachta indica oil has shown lower iodine values (91.2) and much better cloud (−2.6 °C) and pour point (−4.9 °C) than pure Azadirachta indica oil. In conclusion, the crude oil needs to be vacuum fractioned for superior biodiesel production for direct utilization in engine and consistent quality production.