This
work reports the production of fatty acid methyl esters (FAMEs)
and fatty acid ethyl esters (FAEEs) by means of waste fried oil (WFO)
transesterification using methanol and ethanol at supercritical conditions,
in a continuous catalyst-free process. Transesterification experiments
were performed from 573 to 623 K, at 10, 15, and 20 MPa, with oil/alcohol
molar ratios of 1:20, 1:30, and 1:40 and water addition to alcohol
of 0, 5, and 10 wt %. The extent of the reaction was explored using
a novel parameter, convertibility, which corresponds to the maximum
ester content attainable from the feedstock (92.1%). The highest FAME
and FAEE contents achieved were 81.7 and 82.2%, respectively. Results
show that transesterification of WFO in methanol was more efficient
than that in ethanol, the temperature had the strongest influence,
and the addition of water considerably improved the ester yield.
This work reports the enzymatic production of mono- and diacylglycerols under the influence of ultrasound irradiation, in a solvent-free system, with and without the presence of surfactants at a constant temperature of 65°C, glycerol to oil molar ratio of 2:1 and a commercial immobilized lipase (Novozym 435) as catalyst. For this purpose, two operation modes were adopted: the use of a sonotrode (ultrasonic probe), without agitation, varying reaction time, irradiation amplitude (25-45% of the total power) and type of surfactant, and a mechanically stirred reactor (600 rpm) under ultrasound irradiation in a water bath, testing different surfactants. Results show that very satisfactory MAG and DAG yields, above 50 wt.%, can be obtained without the use of surfactant, at mild irradiation power supply (∼130 W), with no important enzyme activity losses verified, in a relatively short reaction time (2h), and low enzyme content (7.5 wt.%). Also, reaction kinetic results show that contents of MAG+DAG as high as ∼65 wt.% can be achieved at longer times (6h), indicating a promising route for producing MAG and DAG using ultrasound irradiation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.