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

Laboratory for Advanced Materials and New Catalysis, School of Chemistry and Materials Science, Hubei University, Wuhan 430062, China,Laboratory of Natural Gas Utilization and Applied Catalysis, Dalian Institute of Chemical Physics of Chinese Academy of Sciences, Dalian 116023,China, and Jingmen Technological College, Jingmen 448000, ChinaReceived June 30, 2004

Advances in Homogeneous and Heterogeneous Catalytic Asymmetric Epoxidation

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

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Chalcone: A Privileged Structure in Medicinal Chemistry.

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

This review focuses on a new concept in catalytic asymmetric reactions that was first realized for the use of heterobimetallic complexes. As these heterobimetallic complexes function as both a Bronsted base and as a Lewis acid, just like an enzyme, they make possible a variety of efficient catalytic asymmetric reactions. This heterobimetallic concept should prove to be applicable to a variety of new asymmetric catalyses. The first part of this review describes the development of rare-earth–alkali metal complexes such as LnM3tris(binaphthoxide) complexes (LnMB, Ln = rare-earth metal, M = alkali metal), which are readily prepared from the corresponding rare-earth trichlorides or rare-earth isopropoxides, and their application to catalytic asymmetric synthesis. By using a catalytic amount of LnMB complexes several asymmetric reactions proceed efficiently to give the corresponding desired products in up to 98% ee: LnLB-catalyzed asymmetric nitroaldol reactions (L = Li), LnSB-catalyzed asymmetric Michael reactions (S Na), and LnPB-catalyzed asymmetric hydrophosphonylations of either imines or aldehydes (P K). Applications of these heterobimetallic catalysts to the syntheses of several biologically and medicinally important compounds are also described. Spectral analyses and computational simulations of the asymmetric reactions catalyzed by the heterobimetallic complexes reveal that the two different metals play different roles to enhance the reactivity of both reaction partners and to position them. From mechanistic considerations, a useful activation of the heterobimetallic catalyses was realized by addition of alkali metal reagents. The second part describes the development of another type of heterobimetallic catalysts featuring Group 13 elements such as Al and Ga as the central metal. Among them, the AlLibis(binaphthoxide) complex (ALB) is an effective catalyst for asymmetric Michael reactions, tandem Michael–aldol reactions, and hydrophosphonylation of aldehydes.

Asymmetric Catalysis with Heterobimetallic Compounds

Immobilized Candida antarctica lipase-catalyzed alcoholysis of cotton seed oil in a solvent-free medium.

Transesterification reaction of the fat originated from solid waste of the leather industry

In this study, the esterification of oleic acid with a fraction of fusel oil was investigated The variables that affect ester yield, such as temperature, molar ratio of oleic acid to alcohol, and amount of catalyst, were determined Powdered silica gel was chosen to remove water instead of granular silica gel, magnesium sulfate, or benzene The behavior of amyl alcohols and the fusel oil fraction was compared The esterification reaction was carried out under the reaction conditions selected as optimal, and the ester conversion of the reaction was 973% The product mixture compressed products, excess reactants, catalyst, and desiccant Oleate ester and oleic acid (27%) were obtained using the refinement steps of filtration, evaportation, washing with distilled water, and drying over sodium sulfate

Esterification Reaction of Oleic Acid With a Fusel Oil Fraction for Production of Lubricating Oil

Polyleucine-based systems have been used to catalyse the asymmetric oxidation of a variety of alkyl enones 1–4, 9–14, an enynone 16 and a dienone 17 to afford the corresponding epoxides 5–8, 18–26 in good to excellent yield and optical purity. A range of enediones 30–32, 34 and one unsaturated keto ester 33 have also been epoxidised stereoselectivley to afford optically active epoxides 35–39. The epoxidations were carried out with basic peroxide as the oxidant; the polyleucine catalyst was prepared from leucine N-carboxyanhydride using 1,3-diaminopropane, water (employing a humidity cabinet) or a polystyrene immobilised amine as the intiator. Preliminary mass spectral data on material derived from L-leucine and 1,3-diaminopropane (DAP-PLL) suggest that the catalyst consists of material that contains 22 ± 10 leucine residues.

Development of the julia asymmetric epoxidation reaction. part 2. application of the oxidation to alkyl enones, enediones and unsaturated keto esters

Glycerolysis of palm and palm kernel oils were conducted using a commercial 1,3-specific lipase from Humicola lanuginosa (trade name: SP 398) as catalyst (500 units lipase g−1 oil) at 40 °C and oil:glycerol (1:2 mol mol−1) in a solvent-free system. After 24 h, the glycerolysis products of palm and palm kernel oils consisted of 23% triacylglycerols, 18% monoacylglycerols, 38% diacylglycerols and 18% triacylglycerols, 31% monoacylglycerols, 42% diacylglycerols, respectively. The monoacylglycerol fraction of the glycerolysis product of palm oil was enriched in oleic acid. Palmitic acid content of the monoacylglycerol fraction of the same product was less than that of the original oil. Under the same conditions, monacylglycerol fraction of the palm kernel oil glycerolysis product was enriched in palmitic, stearic and oleic acids.

Solvent-free glycerolysis of palm and palm kernel oils catalyzed by commercial 1,3-specific lipase from Humicola lanuginosa and composition of glycerolysis products

Melek Tüter

Papers

Immobilized Candida antarctica lipase-catalyzed alcoholysis of cotton seed oil in a solvent-free medium.

Transesterification reaction of the fat originated from solid waste of the leather industry

Esterification Reaction of Oleic Acid With a Fusel Oil Fraction for Production of Lubricating Oil

Development of the julia asymmetric epoxidation reaction. part 2. application of the oxidation to alkyl enones, enediones and unsaturated keto esters

Solvent-free glycerolysis of palm and palm kernel oils catalyzed by commercial 1,3-specific lipase from Humicola lanuginosa and composition of glycerolysis products