Ester reactions of fatty materials

Ultrasonic enhancement of the acidity, surface area and free fatty acids esterification catalytic activity of sulphated ZrO 2 –TiO 2 systems

“…triglycerides, into biodiesel is the transesterification reaction [1,2]. Transesterification is a process where triglycerides contained in vegetable oils or animal fats react with an alcohol, usually methanol, yielding fatty acid methyl esters (FAME) and glycerol in presence of an alkaline catalyst [3]. The main problem posed by the use of alkaline catalysts is represented by the obligation of using feedstock with very low acidity (< 0.5% wt).…”

Animal Fat Wastes for Biodiesel Production

“…To get a better understanding of challenges involved on biodiesel synthesis from animal fat wastes, a brief review regarding to fundamental reactions of carboxylic acids and esters is presented (Formo, 1954;Carey & Sundberg, 1983;Morrison & Boyd, 1996). As illustrated in figure 6a, carboxylic acids originate their salts (soaps) by treatment with aqueous alkaline solutions (hydroxides or carbonates).…”

“…Their compositions are primarily based on triacylglycerols (TAG), which molecules consist of a glycerol backbone attached by ester bonds to three long-chain carboxylic acids (fatty acids). Reactions of ester linkages of oils and fats were recognized a long time by their technological importance (Formo, 1954). Nowadays, non-hydrolytic ester reactions (esterification and interesterification) play a fundamental role in the applied chemistry.…”

“…Homogeneous alkali-catalyzed transesterification is the most widely employed industrial process for biodiesel production (Helwani et al, 2009;Atadashi et al, 2010;Leung et al, 2010). This fact is because the base-catalyzed reation is faster than the acid one under mild conditions (Formo, 1954) resulting in a fuel-grade biodiesel. Alkaline catalysts are furthermore less corrosive than acidic compounds.…”

Producing biodiesel from yellow greases with high free fatty acids

“…Les esters gras sont constitués de triglycérides solides à température ambiante dans le cas des graisses ; et liquides à température ambiante dans le cas des huiles. La réaction de trans-estérification peut s'écrire [8,9,10] :…”