The kinetics of the transesterification of phosphatidylcholine (PC) with α-linolenic acid ethyl ester (ALAEE) catalyzed by immobilized lipase in hexane was studied. The reaction proceeded via a Ping-Ping Bi-Bi mechanism without inhibition by both the substrates at various concentrations tested. A reaction kinetic model was proposed with the experimental data. The kinetic constants of the model ...

Biodiesel was produced via transesterification reaction catalyzed by acids, bases, enzymes or supercritical fluids. The catalysis homogeneous heterogeneous and the process could be carried out in batch using a continuous flow process. Microreactors allowed us to obtain better control of experimental variables, such as temperature, pressure rate, carrying reactions safe conditions, avoiding exot...

The synthesis of L-ascorbyl flurbiprofenate was achieved by esterification and transesterification in nonaqueous organic medium with Novozym 435 lipase as biocatalyst. The conversion was greatly influenced by the kinds of organic solvents, speed of agitation, catalyst loading amount, reaction time, and molar ratio of acyl donor to L-ascorbic acid. A series of solvents were investigated, and ter...

The objective of this research is to develop a kinetic model to describe the transesterification of soybean oil with methanol using NaOH-impregnated calcined oyster shell (Na-COS). Batch experiments were performed via a two-factor randomized complete block design using a molar ratio of methanol to oil (MR) of 6, 12, and 18 and catalyst loadings (CL) (mass of catalyst/mass of oil in %) of 2%, 4%...

The enzymatic kinetic resolution of tert-butyl 2-(1-hydroxyethyl) phenylcarbamate via lipase-catalyzed transesterification reaction was studied. We investigated several reaction conditions and the carbamate was resolved by Candida antarctica lipase B (CAL-B), leading to the optically pure (R)- and (S)-enantiomers. The enzymatic process showed excellent enantioselectivity (E > 200). (R)- and (S)...

the present study has been focused on the acid and base transesterification of animal fats (dairy cow and beef) to produce biodiesel by varying process parameters such as catalyst amount, catalyst nature, reaction time and temperature. the maximum biodiesel yield after acid catalysis was 94.1 ± 2.43 and 98.4 ± 2.3 percent for dairy cow and beef tallow, respectively. the quantity of biodiesel ob...

The inconveniences of the conventional method for biodiesel production by alkaline catalysis suggests research towards alternative methods, with the non-catalytic transesterification using an alcohol at supercritical conditions proposed as a promising technique for biodiesel production. The so-called supercritical method (SCM) has powerful advantages over conventional techniques, such as fast r...

Biodiesel production is worthy of continued study and optimization of production procedures because of its environmentally beneficial attributes and its renewable nature. Transesterification of triglycerides using supercritical ethanol on ionexchange resin catalyst was investigated to study the ethyl ester conversion process. The reaction parameters investigated were the reaction time, pressure...

Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 °C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 °C. For the distribution of methanol between beef tallow methyl esters (BTME) and glycerol, the percentage of total methanol in the glycerol...

Uridine-3'-phosphorothiolate triesters bearing lipophilic moieties were prepared via Michaelis-Arbuzov chemistry. Subsequent deprotection of the S-cholesteryl phosphorothiolate triester afforded the corresponding diester which underwent spontaneous Cyclization to cleanly afford uridine 2',3'-cyclic phosphate. This transesterification reaction could be expedited by treatment with iodine under mi...