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

Activity of solid catalysts for biodiesel production: A review

The production of biodiesel is greatly increasing due to its enviromental benefits However, production costs are still rather high, compared to petroleum-based diesel fuel The introduction of a solid heterogeneous catalyst in biodiesel production could reduce its price, becoming competitive with diesel also from a financial point of view Therefore, great research efforts have been underway recently to find the right catalysts This paper will be concerned with reviewing acid and basic heterogeneous catalyst performances for biodiesel production, examining both scientific and patent literature

Heterogeneous catalysts for biodiesel production

Biodiesel is a clean-burning fuel produced from grease, vegetable oils, or animal fats. Biodiesel is produced by transesterification of oils with short-chain alcohols or by the esterification of fatty acids. The transesterification reaction consists of transforming triglycerides into fatty acid alkyl esters, in the presence of an alcohol, such as methanol or ethanol, and a catalyst, such as an alkali or acid, with glycerol as a byproduct. Because of diminishing petroleum reserves and the deleterious environmental consequences of exhaust gases from petroleum diesel, biodiesel has attracted attention during the past few years as a renewable and environmentally friendly fuel. Since biodiesel is made entirely from vegetable oil or animal fats, it is renewable and biodegradable. The majority of biodiesel today is produced by alkali-catalyzed transesterification with methanol, which results in a relatively short reaction time. However, the vegetable oil and alcohol must be substantially anhydrous and have a low free fatty acid content, because the presence of water or free fatty acid or both promotes soap formation. In this article, we examine different biodiesel sources (edible and nonedible), virgin oil versus waste oil, algae-based biodiesel that is gaining increasing importance, role of different catalysts including enzyme catalysts, and the current state-of-the-art in biodiesel production.

/pdf/biodiesel-production-current-state-of-the-art-and-challenges-28amo4npwv.pdf

Biodiesel production--current state of the art and challenges.

Increasing number of researches focusing on the use of solid heterogeneous catalysts for the production of biodiesel provides evidence that these catalysts continue to evolve as viable alternatives. While liquid alkaline metal alkoxides remain to be appealing in the industries, it is expected that solid base catalyst will soon become more attractive due to the economics and environmental concern. Limited researches have shown that the conversion by solid base catalysts was comparable to that of the existing alkoxide system. This paper reviews various types of heterogeneous solid acids and bases in the production of biodiesel from transesterification of triglycerides. Unconventional enzymatic and non-catalytic supercritical methanol transesterification are also presented. The yields and conversion from various catalytic systems are compared, and the advantages and disadvantages of the systems discussed.

Solid heterogeneous catalysts for transesterification of triglycerides with methanol: A review

Biodiesel was produced by transesterification of soybean oil with methanol using ZnO loaded with KF as a solid base catalyst. It was found that the catalyst with 15 wt.% KF loading and calcined at 873 K showed the optimum activity. XRD, IR and Hammett indicator method were employed for the catalyst characterization. The results showed the activity of the catalysts was correlated with their basicity. The influence of various reaction variables on the conversion was also discussed.

Xiaoming Huang

Papers

Synthesis of Biodiesel from Soybean Oil using Heterogeneous KF/ZnO Catalyst

Soybean oil methyl esters preparation using NaX zeolites loaded with KOH as a heterogeneous catalyst