The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.

Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: A review

Integrated biodiesel production: a comparison of different homogeneous catalysts systems.

Progress in biodiesel processing

Enzymatic biodiesel production has been investigated intensively, but is presently employed industrially only in a 20,000 tons/year pilot plant in China (Du et al. [2008] Appl Microbiol Technol 79(3):331-337). This review presents a critical analysis of the current status of research in this area and accentuates the main obstacles to the widespread use of enzymes for commercial biodiesel transesterification. Improved results for enzymatic catalysis are seen with respect to increased yield, reaction time and stability, but the performance and price of the enzymes need further advances for them to become attractive industrially for biodiesel production. Critical aspects such as mass transfer limitations, use of solvents and water activity are discussed together with process considerations and evaluation of possible reactor configurations, if industrial production with enzymes is to be carried out. Results of published studies on the productivity of enzymes are also presented and compared to the use of chemical catalysts.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/bit.22256

A review of the current state of biodiesel production using enzymatic transesterification

A review on novel processes of biodiesel production from waste cooking oil

A continuous process for the transesterification of triglycerides to methyl esters was investigated in a pilot plant. The process was equipped with a motionless and a high-shear mixer. The experimental studies explored variations in the mixing intensity, stoichiometry, and catalyst concentration on the overall conversion. The combined as well as individual effect of mixers was examined. The developed process resulted in high conversions of vegetable oils into methyl esters. Conversion of triglycerides to methyl esters in excess of 98% was achieved. Larger excess amounts of alcohol favored higher conversions. The motionless and high-shear mixers each provided adequate mixing for the process. Higher catalyst concentrations resulted in higher conversions but increased the solubility of methyl esters in the glycerol layer. This reduced the amount of methyl esters separated by gravity settling.

/pdf/a-continuous-process-for-the-conversion-of-vegetable-oils-56fphavblw.pdf

A continuous process for the conversion of vegetable oils into methyl esters of fatty acids

A continuous process for the glycerolysis of soybean oil with pure and crude glycerol, the co-product from the transesterification of soybean oil, was investigated in a pilot plant. The process was equipped with a static and a high-shear mixer. The experimental studies explored the effects of variations in mixing intensity, temperature, reactant flow rates, and reactant stoichiometry on the formation of MG and DG. The developed process resulted in high conversion of TG to MG. The most favorable conditions were 230°C, 40 mL/min total flow, 25 min of reaction time, 2.5∶1 molar ratio of glycerol/soybean oil, and 3600 rpm for the reactions involving crude glycerol where the concentrations of MG and DG in the product were about 56 and 36 wt%, respectively. Under similar conditions, glycerolysis of pure glycerol resulted in 58% MG and 33% DG. In general, higher temperatures and mixing intensities favored the conversion of TG to MG and DG. Reaction temperature had a greater influence on the extent of the reaction than mixing. The formation of MG approached equilibrium for nearly all cases under investigation.

/pdf/a-continuous-process-for-the-glycerolysis-of-soybean-oil-5fyqsem66q.pdf

A Continuous Process for the Glycerolysis of Soybean Oil

Over the last few years fa,l.tj acid methyl earzxa have asaum*rl inlportanie as research has intensified on the utilization o i vegetable oil8 and animal fats derisarives fiom liquid hlels (bet.tw known a5 hiodi~srl) . Traditional ba*t,ch processing has been m d still is rhr mort widely ~med process fur this i.onvn.rian. Xtx-and more efficient processing schemes. for Isle scale prodnction of bioiliesel for file1 parpases, is a. key for commercialization of biodierzl. In i,hia study a continnous process for the traniesterification of triglycerides 10 methyl r r t w was in-iestigated. This process is based an s combined high shear and motionless reactor system The experimental studies rxplorrd the variations in the mixing intensity, stoichiometry and cata,lyst concentratior, an the o?rrall ranversion.

/pdf/a-continuous-process-for-the-conversion-of-vegetable-oils-47knjj5qdr.pdf

D. Harkey

Papers

A continuous process for the conversion of vegetable oils into methyl esters of fatty acids

A Continuous Process for the Glycerolysis of Soybean Oil

A Continuous Process for the Conversion of Vegetable Oils into Biodiesel