Production of biodiesel from unused algal biomass in Punjab, India

Biodiesel from inedible sources has become prominent in last few decades. But it is economically incompatible with petroleum diesel. At the same time, both petro-diesel and biodiesels are concerned with environmental pollution, global warming, etc. Algae, on the other hand, utilize CO2 for their growth and can minimize some sort of pollution level and results in carbon credit for a country. In Punjab, India, algae are seen to grow in many water bodies. But all those are taken away and dumped in vats. Some of this huge biomass was used for production of biodiesel in this work. Extraction of oil from algae was conducted by using Soxtherm（solvent extraction）. An amount of 9 wt% of algal oil was extracted by comparatively costly hexane, whereas 8% extraction was done by cheaper acetone. In the transesterification reaction, molar ratio（methanol： oil） of 6：1, catalyst（KOH） concentration of 3 wt%, reaction temperature of 60 °C, 60 min reaction time and a settling time of 2.5 h were found to be optimum conditions to get maximum ester with minimum free fatty acid content and viscosity. A statistical analysis for the transesterification procedure also showed a methanol-to-oil molar ratio of 6：1 and catalyst concentration of 3 wt% to be the optimum. Characterization of biodiesel was done and compared with ASTM/BIS standards. Most important properties of biodiesel ester like viscosity（3.12 c St or 3.12 mm2/s）, cloud and pour point（-1 and-6 °C, respectively）, flash and fire point（153 and 158 °C）, carbon residue content（0.03%）, acid number（0.36 mg of KOH/gm） were within the range of concerned standards.

Scope of biodiesel from oils of woody plants:a review

Non-edible oils obtained from chosen non-conventional woody plants are considered as potential raw materials for biodiesel production.These plants mostly grow in wastelands.Structural characteristics of these oils as raw material are very much in tune with the properties of biodiesel such as long-chain hydrocarbon,having an adequate level of unsaturation with branched chain.Four primary methods are being followed to make biodiesel from vegetable oil.They are direct use through blending,microemulsion,thermal cracking(pyrolysis)and transesterification.Non-edible oil would eliminate the issue of food vs fuel.The biodiesel manufactured from oils of woody plants may partially reduce the demand for liquid-fuel energy and addresses the environmental consequences of using fossil fuels.Oil from a total of 17 species of woody plants(Angiosperms)belonging to 14 families are considered in this paper.The habit,habitat and geographical distribution of each species are also presented.The physico-chemical properties of their oil,with special reference to the fatty-acid profile that ultimately decides the characteristics of the biodiesel prepared from them,are reviewed.

Development of a combined approach for improvement and optimization of karanja biodiesel using response surface methodology and genetic algorithm

This paper described the production of karanja biodiesel using response surface methodology （RSM） and genetic algorithm （GA）. The optimum combination of reaction variables were analyzed for maximizing the biodiesel yield. The yield obtained by the RSM was 65% whereas the predicted value was 70%. The mathematical regression model proposed from the RSM was coupled with the GA. By using this technique, 90% of the yield was obtained at a molar ratio of 38, a reaction time of 8 hours, a reaction temperature of 40 ℃, a catalyst concentration of 2% oil, and a mixing speed of 707 r/min. The yield produced was closer to the predicted value of 94.2093%. Hence, 25% of the improvement in the biodiesel yield was reported. Moreover the different properties of karanja biodiesel were found closer to the American Society for Testing ＆ Materials （ASTM） standard of biodiesel.

Cultivation of Chlorella sp.HQ in inland saline-alkaline water under different light qualities

Inland saline-alkaline water can be used for the low-cost cultivation of microalgae,but whether algal biomass under various light sources has the potential to produce biodiesel remains to be developed.Herein,the influence of different light-emitting diode(LEDs)light colors(blue,red,white,mixed blue-red,and mixed blue-white LED)on the growth performance,lipid accumulation,and fatty acid composition of Chlorella sp.HQ cultivated in inland saline-alkaline water was investigated.The highest algal density was obtained under blue LEDs at the end of cultivation,reaching 1.93±0.03 × 10^(7) cells/mL.White LEDs can improve biomass yield,total lipid yield,and triacylglycerol yield per algal cell.The main fatty acid components of Chlorella from inland saline-alkaline water were palmitic acid and linoleic acid.The Biodiesel Analyzer software was used to predict algal biodiesel quality by estimating different quality parameters.The cetane number,kinematic viscosity,and density of Chlorella biodiesel were 51.714-67.69,3.583-3.845 mm^(2)/s,and 0.834-0.863 g/cm^(3),respectively.This flirther proved that the Chlorella biomass obtained from inland saline-alkaline water has the potential to be used as a high-quality biodiesel feedstock.