Solid–Liquid Equilibria in the Binary Systems of Saturated Fatty Acids or Triglycerides (C12 to C18) + Hexadecane

Abstract

Solid–liquid equilibria (SLE) for the binary systems of C12–C18 saturated fatty acids or their triglycerides + hexadecane (systems of dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acic), octadecanoic acid (stearic acid), 1,2,3-propanetriyl tridodecanoate (trilaurin), 1,2,3-propanetriyl tritetradecanoate (trimyristin), 1,2,3-propanetriyl trihexadecanoate (tripalmitin), or 1,2,3-propanetriyltrioctadecanoate (tristearin), + hexadecane) were measured in the hexadecane fractions of 0 to 1 and temperatures from (273.2 to 353.2) K, using differential scanning calorimetry. These systems were selected as model systems for blending oily content extracted from restaurant trap grease with fossil fuel oils. The obtained liquidus curves were discussed in terms of the effects of carbon chain length, chemical form, and variation in the liquid component. In addition, the experimental liquidus curves were compared with predictions based on ideal solution approximation and on the LLE-UNIFAC and Dortmund-UNIFAC models. The triglyceride and hexadecane binary systems were close to the ideal solution, while the fatty acid–hexadecane binary systems were not. The Dortmund-UNIFAC model successfully predicted all liquidus curves of the nonideal, fatty acid–hexadecane systems.

Measurement of Vapor Pressures and Melting Properties of Five Polybrominated Aromatic Flame Retardants

“…The purity of PBP used here was almost 100%, whereas that of the PBP used in our earlier study was only 96%, because a higher purity sample was not available at that time. In another earlier study, we had confirmed that the DSC system (which is exactly the same as the one used here) provides Δ fus H values within at most 10% deviations from other literature data …”

“…In another earlier study, we had confirmed that the DSC system (which is exactly the same as the one used here) provides Δ fus H values within at most 10% deviations from other literature data. 51 The order of the melting temperatures was PBT > TBX > PBP > PBEB > TBP-DBPE. Among the five BFRs, PBP and TBP-DBPE had an additional peak, respectively, and we supposed that these peaks were due to a solid-state phase transition.…”

“…The temperature and heat flow were calibrated using standard materials, in accord with the methods used in a previous study. 51 The measurements were performed five times for each substance.…”

“…The melting temperature ( T m ) and heat of fusion (Δ fus H ) were determined from the onset temperature and the area of the melting peak of each measurement, respectively. The temperature and heat flow were calibrated using standard materials, in accord with the methods used in a previous study . The measurements were performed five times for each substance.…”

A Simple Method for the Detection of Long-Chain Fatty Acids in an Anaerobic Digestate Using a Quartz Crystal Sensor

“…On the basis of the experimental study on equilibria in fatty acid/triglyceride systems, the mixture of palmitic acid and triolein can be considered an ideal solution [32]; thus, γ i org is 1. From our recent studies [33], ∆H fus and T m of palmitic acid are 335.6 K and 55,840 J/mol, respectively. Therefore, the water-solubility of palmitic acid in the mixture of palmitic acid, triolein, and water is expressed as follows:…”