@inproceedings{EckertDasguptaSelgeetal., author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Selge, Benjamin and Ay, Peter}, title = {Liquid solid phase behavior of ternary fatty acid systems of palmitic, stearic, oleic and linoleic acid}, series = {Book of Abstracts of the 8th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry Karlsruhe, March 29-31, 2015}, booktitle = {Book of Abstracts of the 8th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry Karlsruhe, March 29-31, 2015}, publisher = {abiosus e.V. Conferences}, address = {Karlsruhe, Germany}, pages = {S. 73}, abstract = {Enrichment of natural unsaturated fractions by melt crystallization processes has already been proved to be effective in prior investigations [1]-[3]. Palmitic, stearic, oleic, linoleic and linolenic acid are the five main fatty acids present in most of these plant based natural oils. There is quite a bit of information about the liquid solid phase behavior of binary mixtures such as palmitic-oleic, stearic-oleic and palmitic-stearic acid mixtures in literature [4]-[6]. Recent investigations have shown phase diagrams of real natural oil based fatty acid systems containing up to 19\% saturated content (11\% stearic acid and 8\% palmitic acid) [7]. Yet, there is hardly any information regarding ternary systems as those of palmitic-stearic-oleic and palmitic-stearic-linoleic acids. In this work, synthetic mixtures have been used in order to obtain a complete overview of the liquid solid phase diagrams of these ternary mixtures. To imitate naturally occurring mixtures, a mixture with 1:1 ratio of palmitic stearic acid was prepared. Varying amounts of either oleic or linoleic acids were added to this mixture in order to obtain the entire range required for the phase diagrams. These mixtures were then subjected to a specific profile with a wide temperature range in a Differential Scanning Calorimeter (DSC) so as to record every phase transition. This study successfully concludes that these complex mixtures could be treated as binary mixtures of their saturated and unsaturated contents. This is because there were essentially two main peaks noted in the DSC thermograms. It is to be noted that there was a third peak, assumed to represent the solid transition, in mixtures containing oleic acid. This has already been shown in detail and discussed in prior investigations [6], [7]. Another major discovery was that the solidus line depends on the type of the unsaturated content, that is, the degree of unsaturation, in the mixture.}, language = {en} } @misc{DasguptaRettigAy, author = {Dasgupta, Sunanda and Rettig, Florian and Ay, Peter}, title = {Nucleation kinetics during melt crystallization of plant based high oleic and linoleic polyunsaturated fatty acid mixtures}, series = {Crystal Growth \& Design}, volume = {16}, journal = {Crystal Growth \& Design}, number = {2}, issn = {1528-7505}, doi = {10.1021/acs.cgd.5b01432}, pages = {861 -- 866}, abstract = {Nucleation kinetics of high linoleic and high oleic polyunsaturated fatty acid (PUFA) mixtures were investigated during melt crystallization by means of an Focused beam reflectance measurement (FBRM) sensor. Samples were analyzed thermally and chemically in the Differential Scanning Calorimeter (DSC) and Gas Chromatograph (GC) respectively. Investigations showed that a high oleic content in the PUFA mixtures lead to higher induction times, τi. Unlike previous investigations, a clear relation between τi and cooling rates was established. τi increases with increasing cooling rates and decreasing supercooling. Activation energies of nucleation, ∆Gc' were determined by means of the Fisher Turnbull equation wherein ∆Gc' decreases exponentially with increasing supercooling. Investigations and further evaluations conclude that while the plot establishes the effect of supercooling on ∆Gc' , it does not incorporate the effects of molecular diffusion or the cooling rate. Hence, 3D modeling was performed to visualize the combined effects of cooling rate and supercooling on induction time.}, language = {en} } @misc{OyegbileAyNarra, author = {Oyegbile, Benjamin and Ay, Peter and Narra, Satyanarayana}, title = {Optimisation of micro-processes for shear-assisted solid-liquid separation in a rotatory batch flow vortex reactor}, series = {Journal of Water Reuse and Desalination}, volume = {6}, journal = {Journal of Water Reuse and Desalination}, number = {1}, doi = {10.2166/wrd.2015.057}, pages = {125 -- 136}, abstract = {This paper reports the study of micro-processes in a novel pre-treatment technique using a pellet forming batch flow vortex reactor of cylindrical shape that consists of axially revolving rotor plates between fixed stator plates. The suspension was first mixed with high molecular weight synthetic polymers by stirring for approximately 50 seconds and then agitated for 20 minutes. The process was optimised for a number of operating conditions including polymer type and dosing regimen, rotation speed, wall-plate gap distance, residence time and suspension filling method. The results of the investigation show that optimising a number of process variables that influence floc formation and growth, along with specific apparatus construction and geometry, help to maintain the suspension in a metastable state that is crucial for the formation of pellet-like compact agglomerates with better dewaterability and uniform aggregate size. A maximum dry solids content of 28.3\% after gravity dewatering through a 0.5 mm sieve was recorded during the investigation, with a maximum particle removal efficiency of 97.5\%.}, language = {en} }