Kinetics of reactive extraction of free fatty acids in jatropha oil with monoethanolamine in methanol: A key biodiesel pre-processing step

Unrefined vegetable oils and fats contain free fatty acids and they ought to be minimized for use in food and nonfood applications. Traditional deacidification of vegetable oils and fats adopts alkali neutralization for the removal of free fatty acids. Here, a simple method for the removal of free fatty acids from jatropha oil by reactive extraction using monoethanolamine in methanol is proposed. Reactive extraction kinetic studies with initial free fatty acids concentration (0.1-0.5 kmol/m3) using monoethanolamine (0.4141-1.6568 kmol/m3) in methanol at 30 degrees C was performed and investigated. Parameters like distribution coefficient, equilibrium complexation constant for free fatty acids extraction were obtained to arrive at equilibrium and kinetic conclusions. Most importantly, the criteria for reaction regime was established through Hatta number. The study revealed that reactive extraction of free fatty acids using monoethanolamine in methanol falls under reaction regime 2. The study demonstrated that reactive extraction was highly successful in reduction of the free fatty acids in jatropha oil. Further biodiesel was prepared using the deacidified oil and the specifications obtained were well within the standard ASTM limits.

Automated summary

This study proposes a simple method for removing free fatty acids from unrefined vegetable oils using reactive extraction with monoethanolamine in methanol. The study investigates the kinetic parameters and establishes the reaction regime for the extraction process. The results show that reactive extraction is highly effective in reducing the free fatty acid content in jatropha oil. Biodiesel prepared from the deacidified oil meets the ASTM standards.