Properties and separations of plant-derived chemicals

Biorenewable processing is highly dependent on the feasibility of separations. This work considers the development of fractionation principles and thermodynamic properties useful for process designs in two main areas: fractionation of lipids; and measurement/prediction of properties for upgrading of organic acids and their derivatives.; Ricinolein can be separated from the other triglycerides in castor oil by adsorbing it onto acidic adsorbents or by concentrating it in the effluent stream of fixed-beds using non-polar adsorbents. Solvents play an important role in adsorption. Replacing hexane with ethanol, the hydroxylated triglycerin, which is preferentially adsorbed by Florisil in hexane will be released in the effluent. The adsorbent capacity of Florisil to the total oil also significantly changes from 17 wt. % in hexane to 6 wt. % in ethanol.; Extractions of plant lipids usually use solvent mixtures of chloroform-methanol. However, chloroform is very toxic and a possible carcinogen in humans. A proposed process developed in this work successfully extracts sulfoquinovosyl diacylglycerol (SQDG) from alfalfa and isolates it from other plant lipids using non-chlorinated solvents. Lipases are deactivated during extraction using isopropanol at 50-55°C. Hexane-methanol mixtures are used in extraction and subsequent liquid-liquid partitioning to remove proteins and phospholipids. The yield of SQDG using the proposed process is comparable to literature and the amount of solvent used is less than 30 vol. % of the value reported in literature.; For purposes of upgrading of lactic acid, a model is developed for the oligomer distribution in aqueous solutions. The model is extended to multicomponent VLE in mixtures involving lactic acid and ethyl lactate oligomers. A P-x-y apparatus is also developed to measure VLE and VLLE at temperatures between 25°C and 80°C and pressures down to 0.7 kPa. Data pass either the area or point-to-point thermodynamic consistency test.; Finally, the Step Potential Equilibria and Dynamics (SPEAD) molecular simulation method is adapted for predicting vapor pressures of oxygenated compounds. A method is developed for optimization of five and nine variable functions. From this study, parameters for the secondary -OH, cyclic -0-, and -COO- groups are made available for use in SPEAD. Vapor pressures of esters containing up to 30 carbons are predicted within 25% of the experimental values using these parameters.