Mutual Solubility for Systems Composed of Vegetable Oil + Ethanol + Water at Different Temperatures

Abstract

This study presents liquid−liquid equilibrium data for systems of interest in biodiesel production and the refining of edible oils by liquid−liquid extraction. These systems are composed of vegetable oils + anhydrous ethanol + water, at temperatures ranging from (298.15 to 333.15) K. The following vegetable oils were investigated: refined canola oil, refined corn oil, semiprocessed Jatropha curcas oil, and semiprocessed macauba (Acrocomia aculeata) pulp oil. According to the results, the enhancement of temperature within the study ranges increased oil−solvent miscibility in both phases. The liquid−liquid equilibrium experimental data were correlated using the non-random two liquid (NRTL) model. For all of these systems, the global deviations between calculated and experimental data were lower than 0.7 %, showing the good descriptive quality and applicability of the NRTL model in liquid−liquid analysis and computational simulation processes.

Liquid-Liquid Equilibrium for Ternary Systems Containing Ethylic Biodiesel + Anhydrous Ethanol + Refined Vegetable Oil (Sunflower Oil, Canola Oil and Palm Oil): Experimental Data and Thermodynamic Modeling

“…The model in terms of mass fractions was used in the objective function instead of mole fractions due to the large difference in molar masses between vegetable oils and ethanol. This approach was also applied by FollegattiRomero et al (2010) and Lanza et al (2008). In this case, the NRTL-model is expressed as follows:…”

Trends and demands in the solid–liquid equilibrium of lipidic mixtures

“…Crude oils comprise a group of free fatty acids originated from the hydrolysis of the triacylglycerol molecule and consequently, mono-, diacylglycerols and glycerols molecules are also present. Additionally, a fraction of 10 phospholipids (up to 3 %wt for soybean oil), sterols (up to 1.00 %wt for primrose oil), carotenes (up to 0.05 %wt for palm oil), chlorophylls (up to 0.10 %wt for avocado oil), tocopherols and tocotrienols (up to 0.25 %wt for wheat germ oil) are commonly found, as well as several other non-lipidic compounds, minerals 15 and metal ions 10,18,20,[23][24][25] . Most of them are usually removed or reduced during the refining processes, whilst a set of them still remain on the refined final product, such as phospholipids (up to 3 mg/kg), free fatty acids (up to 0,3 %wt) and a small amount of pigments, depending on the source.…”

“…In fact, even some triacylglycerols not present in the original crude oil are sometimes added to the product in order to obtain the desired effects. Additionally, they are also used for the production of other additives in the industry, 15 such as fatty alcohols and fatty esters. Fatty alcohols are produced from fatty acids or even from triacylglycerols by different routes of esterification and hydrogenation 29 , but are also found in small amounts in vegetable waxes such as those from sugar cane, sunflower or peanuts 30 .…”

“…The study of the solid-liquid equilibrium (SLE) of lipidic mixtures is a fundamental tool for the development and 15 optimization of the processing of fatty based products. Fats and oils are remarkable suppliers of food, materials, chemicals and also energy.…”

“…In this case, systems are continuous solid solutions. 15 Frequently, in the crystallization processes of lipidic compounds, associative phenomena can occur during the building of the crystal lattice. Such associative behavior may lead to the appearance of a new crystalline structure that acts as a new compound.…”