What are the products of transesterification?
17.3. 4 Transesterification. Transesterification is defined as the chemical conversion process of triglycerides with alcohol into alkyl esters with the help of a catalyst . In this process, commonly used alcohols are methanol and ethanol due to their low cost and easy availability.
What is the catalyst in transesterification?
Different solid-base catalysts used in transesterification include CaO, MgO, SrO, KNO3/Al2O3, K2CO3/Al2O3 [72, 73], KF/Al2O3, Li/CaO, KF/ZnO, basic hydrotalcite of Mg/Al, Li/Al, anion exchange resins and base zeolites [74, 75].
What happens during transesterification?
The transesterification reaction results in that the glyceride ester is reacted with methanol (approx. 10 %w of the triglyceride) to form three separate FAME methyl esters and in exchange the glycerol is released into the reaction mixture. Reaction equation of the transesterification process.
What is the byproduct of producing biodiesel?
Biodiesel production will generate about 10% (w/w) glycerol as the main byproduct. In other words, every gallon of biodiesel produced generates approximately 1.05 pounds of glycerol. This indicates a 30-million-gallon-per-year plant will generate about 11,500 tonnes of 99.9 percent pure glycerin.
Is transesterification a substitution reaction?
Recognize and understand the most important types of nucleophilic acyl substitution reactions in biology: Transthioesterification, esterification, and transesterification reactions. Conversion of a thioester or ester to an amide. Hydrolysis of a thioester, a (carboxylic) ester, or an amide to a carboxylate.
What is transesterification of triglycerides?
Transesterification (also called alcoholysis) is the reaction of a fat or oil triglyceride with an alcohol to form esters and glycerol. A catalyst is usually used to improve the reaction rate and yield. Because the reaction is reversible, excess alcohol is used to shift the equilibrium to the product side.
How does catalysts play an important role in production of biofuels?
The presence of catalyst increases the rate of the reaction, thereby increasing the yield of the product. Various catalysts are used in the transesterification process for biodiesel production.
What are the stages for biodiesel production process?
The major steps required to synthesize biodiesel are as follows:
- Feedstock pretreatment.
- Product purification.
- Base-catalysed transesterification mechanism.
- Supercritical process.
- Ultra- and high-shear in-line and batch reactors.
- Ultrasonic reactor method.
Why is acid added during the extraction process of biodiesel?
The wash water is separated out similar to solvent extraction (it contains some glycerol), and the trace water is evaporated out of the biodiesel. Acid is added to the glycerol in order to provide neutralized glycerol.
Is transesterification a hydrolysis reaction?
Transesterification is the displacement of alcohol from an ester by another one in a process similar to hydrolysis, except that alcohol is used instead of water . This process has been widely used to reduce the high viscosity of triglycerides.
What is transesterification in biodiesel process?
Transesterification is a chemical reaction used for the conversion of triglycerides (fats) contained in oils, (Feedstocks) into usable biodiesel. Biodiesel produced by the process of transesterification has a much lower viscosity, making it capable of replacing petroleum diesel in diesel engines.
What is the first step in acid catalyzed transesterification?
You’ll notice that the first step of the reaction is protonation of the carbonyl oxygen by the strong acid.
What is the difference between acid-catalyzed and base catalyzed transesterifications?
Homogeneous acid-catalyzed reaction is about 4000 times slower than the homogeneous base-catalyzed reaction. However, acid-catalyzed transesterifications are advantageous than the base catalyzed ones: the performance of the acid catalyst is not strongly affected by the presence of free fatty acids (FFAs) in the feedstock.
What are the types of catalysts used in transesterification?
Catalysts used in transesterification Transesterification reactions are catalyzed by acids, bases and biocatalysts. Classification of the catalysts are given in the flowchart. All the three types of catalysts have been attempted and reported. Heterogeneous catalysts are always advantageous over homogeneous ones.
What is the kinetics of two step acid–base catalyzed transesterification of high FFA?
The present study deals with the kinetics of two step acid–base catalyzed transesterification of high FFA containing WCO under optimum conditions of methanol to oil ratio of 3:7 (v/v), temperature of 65 °C and 50 °C for acid and base transesterification respectively, 400 rpm and catalyst concentration of 1% (w/w) for H 2 SO 4 and 1% (w/w) for NaOH.
What is transesterification in chemistry?
Transesterification is an organic reaction in which an alcohol’s R group is substituted for an ester’s R’ group. In most cases, this is achieved by applying an acid or base catalyst to the reaction mixture. It can also be achieved with the aid of enzyme catalysts (such as lipases).