@misc{EckertDasguptaSelgeetal., author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Selge, Benjamin and Ay, Peter}, title = {Construction and comparison of solid liquid phase diagrams of binary sat-sat and unsat-unsat fatty acid mixtures comprising two of palmitic/stearic/oleic/linoleic/linolenic acid}, series = {Journal of Environmental Research And Development}, volume = {10}, journal = {Journal of Environmental Research And Development}, number = {4}, issn = {0973-6921}, pages = {10}, abstract = {In this paper, binary phase diagrams of the five main fatty acids present in edible oil based mixtures are shown. While previously the binary systems of one saturated and one unsaturated acid were investigated, in this work the binary mixtures comprise of palmitic (C16:0) and stearic acid (C18:0) or a binary mixture of oleic (C18:1), linoleic (C18:2) or linolenic acid (C18:3). In order to obtain the phase diagrams with all the solid liquid and solid phase transitions, the mixtures were analyzed by means of Differential Scanning Calorimetry (DSC). Phase change boundary functions based on thermodynamic models and experimental values were fitted and compared. The phase diagrams obtained show behaviors in good agreement to literature. The paper contributes to the deeper understanding of the essential phase change effects during industrial crystallization processes.}, language = {en} } @misc{KloseReinholdLogschetal., author = {Klose, Markus and Reinhold, Romy and Logsch, Florian and Wolke, Florian and Linnemann, Julia and Stoeck, Ulrich and Oswald, Steffen and Uhlemann, Martin and Ballach, Juan and Markowski, Jens and Ay, Peter and Giebeler, Lars}, title = {Softwood lignin as a sustainable feedstock for porous carbons as active material for supercapacitors using an ionic liquid electrolyte}, series = {ACS Sustainable Chemistry \& Engineering}, volume = {5}, journal = {ACS Sustainable Chemistry \& Engineering}, number = {5}, pages = {4095 -- 4102}, language = {en} } @inproceedings{MarkowskiPempelAy, author = {Markowski, Jens and Pempel, Harry and Ay, Peter}, title = {Recovery of nickel-containing coatings with hydro-biotechnological methods}, series = {COM 2017, Conference of Metallurgists (MetSoc), The 56th Annual Conference of Metallurgists, hosting World Gold and Nickel-Cobalt, August 27-30, 2017, Hyatt Regency Vancouver, British Columbia, Canada}, booktitle = {COM 2017, Conference of Metallurgists (MetSoc), The 56th Annual Conference of Metallurgists, hosting World Gold and Nickel-Cobalt, August 27-30, 2017, Hyatt Regency Vancouver, British Columbia, Canada}, publisher = {Canadian Institute of Mining, Metallurgy and Petroleum}, address = {Vancouver}, isbn = {978-1-926872-36-0}, abstract = {Metal-coated thermoplastic parts find more and more functional and aesthetic applications in the interior and exterior of cars. The vapor-deposited or electroplated coatings are usually composed of a plurality of nickel- and chromium-containing layers, which are applied to copper-containing carrier layers on the polymers. Previously, recycling processes are mainly focussed at the recovery or thermal utilization of the plastics. Targeted and selective recycling of the metallic coatings is usually not carried out. Together with several SME, BTU developed a process, in which a complete and separate recovery of all components in high purity is possible with biotechnological methods. The bioleaching is carried out with iron and sulfur-oxidizing bacteria, esp. Acidithiobacillus ferrooxidans. The copper-containing layers are dissolved in the solution; chromium- and nickel-containing particles are precipitated as solids. After the bioleaching, a mechanical separation of the individual metal-containing components and their separate workup are carried out. End-products are metallic copper, a nickel- and chromium-containing solid and the cleaned plastics. The bioleaching ensures a high purity of the end products. Through the use of bacteria, which are also found in nature, the process is environmentally friendly. Compared to chemical leaching using inorganic acids, considerably shorter leaching times can be achieved. In addition to the optimization of the leaching process, the R/D-project also includes the development and testing of the apparatus technology.}, language = {en} } @misc{EckertDasguptaSelgeetal., author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Selge, Benjamin and Ay, Peter}, title = {Novel model for the prediction of SSLE temperatures and crystallization paths of any mixture containing palmitic, stearic, oleic, linoleic and linolenic acid}, series = {Thermochimica Acta}, volume = {652}, journal = {Thermochimica Acta}, issn = {0040-6031}, doi = {10.1016/j.tca.2017.03.015}, pages = {126 -- 140}, abstract = {A mathematical model for the prediction of phase change temperatures and crystallization paths for mixtures consisting of palmitic (P), stearic (S), oleic (O), linoleic (L) and linolenic acid (Ll) in any distribution is presented in this paper. This model is based on the information gathered from modeled ternary phase diagrams, namely PSO, PSL, PSLl and OLLl, that were based on experimental binary phase diagrams of all possible combinations of these fatty acids. These experimental binary phase diagrams were obtained by means of differential scanning calorimetry and mathematical function fitting, within which the eutectic region of binary palmitic/stearic with oleic/linoleic/linolenic acid was investigated in detail. The basic mathematical model used was previously shown in literature which delivered good results for such systems. The importance of the developed model was then justified by investigations on real and composed synthetic fatty acid mixtures, where a high accuracy of the predicted temperatures could be shown for the technically relevant liquidus and solidus temperatures. A satisfying prediction for thermal events below the first solidus line could be reached as well. This work directly contributes to an enhanced understanding of the thermodynamic and kinetic background of such important mixtures applied in diverse products and industries, thereby showing a large optimization potential for crystallization technologies.}, language = {en} } @inproceedings{DasguptaGlaserAy, author = {Dasgupta, Sunanda and Glaser, Claudia and Ay, Peter}, title = {SLE diagram for a high oleic palm oil based fatty acid mixture at low saturated content}, series = {9th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry, March 19-21, 2017, Karlsruhe, Germany}, booktitle = {9th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry, March 19-21, 2017, Karlsruhe, Germany}, publisher = {Abiosus e.V.}, address = {Oldenburg}, abstract = {Vegetable oils and their derivatives are increasingly replacing mineral oils in their applications.[1,2] Among other constituents in vegetable oil, both saturated and unsaturated fractions are important raw materials. The latter possesses double bonds which can provide as substrates or raw materials for various chemical industries.[3] Fractionation of these oils or as in our case the Poly-Unsaturated Fatty Acid (PUFA) mixture is required so as to generate favorable compositions according to applications. Generation of Solid Liquid Equilibrium (SLE) phase diagrams for real mixtures is extremely important to enable a thorough understanding of the thermodynamics of the fractionation process of crystallization. The PUFA mixture was fractionated in a multistage scrubbing layer crystallizer. The product was put into a decanter centrifuge so as to fractionate them into mother liqor and crystal fraction. The temperature in the jacket was maintained such that △T< 5K from the liquidus point obtained from the Differential Scanning Calorimeter (DSC) thermal analyses. Each crystallizer was also maintained at a temperature 5K below the previous one. This way a slow and successive cooling of the PUFA was achieved such that probes from different fraction could be obtained. They were analyzed thermally and chemically in the DSC and Gas Chromatography - Flame Ionization Detector (GC-FID) setup respectively.[4] Similar to previous literature as in [5], technically relevant partial SLE diagrams for high oleic palm oil was created by fractionating the mixture in a scrubbed layer crystallizer along with their metastable range were determined.[6]}, language = {en} } @phdthesis{Dasgupta, author = {Dasgupta, Sunanda}, title = {Metastable zone determination and nucleation kinetics during melt crystallization of poly-unsaturated fatty acids}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-44175}, pages = {228}, abstract = {The range of application of fatty acids is as broad and varied as the diverse kinds of fatty acids themselves, stretching from bulk scale productions as in the case of biodiesel or lubricant manufacturing over consumer or end products like cosmetics, medicinal or nutritional additives to relatively smaller scale specialty chemicals like epoxy resins, insect repellents and so on. The crystallization temperatures of the unsaturated fatty acids are much lower than those of the saturated ones, which is an important and desirable property for raw materials such as in the production of epoxy resins. Separation and purification of these enriched unsaturated fatty acid fractions depending on their applications is mainly performed by two thermal fractionation processes, namely, distillation and crystallization. The potential behind the success of purification of these multi-component organic fatty acid mixtures with the help of melt crystallization, apart from the fact that it is cost effective owing to the obvious reduction of solvent removal and regeneration steps, is that of the relatively large differences in the melting points of the individual fatty acids. A detailed and fundamental understanding of the crystallization especially nucleation kinetics of a variety of vegetable oil based fatty acid mixtures has been provided in this work. It also describes the solid-liquid phase diagrams of these poly-unsaturated mixtures including their metastable zone widths of nucleation and solidification. This theoretical part of this thesis is a detailed resource on the global production and application of vegetable oils and their derivatives. A clear mathematical and physical road map for the application of the Fisher Turnbull model to calculate the enthalpy values starting from the very basic supersaturation equation has been established and extensively explained as well. Nucleation studies have been carried out on various reactor setups in micro-, milli- and liter-scale. It successfully models the induction times of nucleation as a function of supercooling at different cooling rates both in micro and macro scale. 3D modeling of this parameter to see the combined effects of temperature and in turn viscosity have also been successfully implemented on the milliliter scale results, as more of the bulk nucleation phenomenon was observed in the latter. Fisher Turnbull plot and the Gibbs Thompsons model were adjusted and applied to correlate the Gibbs free energy, involved with the rate of nucleation captured by the FBRM™ (Focused Beam Reflectance Measurement) technology. The scope of this measurement technology was also tested in liter scale. The results showed that FBRM technology is applicable when the solution is relatively dilute and does not have too many overlapping crystals.}, language = {en} } @inproceedings{LogschGlaserBalzetal., author = {Logsch, Florian and Glaser, Claudia and Balz, Jessica and Ay, Peter and Leiker, Matthias and Heiduschke, Rene}, title = {Experimental studies of the pelletizing-flocculation process of ironhydroxide containing suspensions in a Taylor-Couette-Reactor}, series = {Abstracts of the XXIX International Mineral Processing Congress : 17-21 september, 2018}, booktitle = {Abstracts of the XXIX International Mineral Processing Congress : 17-21 september, 2018}, edition = {1. Auflage}, publisher = {Ore and Metals, Publishing House, Moscow}, address = {Moscow}, isbn = {978-5-98191-086-9}, pages = {189}, abstract = {The treatment of iron-hydroxide-containing water from ground water and surface water is achieved by a combination of the process steps of flocculation and subsequent mechanical dewatering. The aim is to create solid pellet structures by extending the structure forming flocculation process with a build-up pelletizing process which can be transferred directly into a drying unit. A Taylor-Couette-reactor (diameter of the inner cylinder - 40 mm, gap width - 5 mm) was used for these experimental studies. To produce the necessary flow profile the inner cylinder was rotated at a speed of 230 rpm. The iron hydroxide-containing suspension (dry matter content: 2 mass \%) was added simultaneously with the addition of a cationic high-molecular flocculant in various flocculant dosages and residence times of 5 to 15 min. The pellets were examined for parameters such as geometric dimensions, dry substance content and dewatering behaviour. As the results show, there is a direct relationship between the residence time and the geometric dimensions of the pellets. After a residence time of 5 min, round pellets with an average diameter of 6 mm were formed. With an increase in the residence time up to 15 min, a compaction of the pellets could be observed, which resulted in an increase in the dry substance content of 8.0 to 11.2 mass \% on average. After completion of the pelletizing process, the pellets were mechanically dewatered by filtration. By applying this innovative wet pelletizing of iron-hydroxide containing suspensions in a Taylor-Couette-reactor, it is possible to carry out the process of flocculation combined with the pellet formation with simultaneous pellet compaction in a single process step. The resulting pellet structures are distinguished from conventional floc structures by an improved water discharge capacity. After classification the pellets can be marked directly as easy-to-handle bulk material, suitable as feedstock in percolation columns for the purification of contaminated fluid streams}, language = {en} } @misc{MarkowskiHintze, author = {Markowski, Jens and Hintze, Helene}, title = {R{\"u}ckgewinnung und Aufbereitung der Kathodenbeschichtungen von Lithium-Ionen-Traktionsakkumulatoren}, series = {Technical Days - Aktuelle Entwicklungen und zuk{\"u}nftige Herausforderungen in der Welt des Trockenzerkleinerns und Sichtens - Symposium 2019}, journal = {Technical Days - Aktuelle Entwicklungen und zuk{\"u}nftige Herausforderungen in der Welt des Trockenzerkleinerns und Sichtens - Symposium 2019}, address = {Hanau}, abstract = {Die energie- und ressourcenschonende Aufbereitung von End-of-life-Lithium-Ionenakkus ist ein gesellschaftliches und wirtschaftliches Erfordernis, da mit dem zunehmenden Einsatz von Elektrofahrzeugen die Zahl von ausgedienten oder defekten Li-Traktionsbatterien zunehmen wird. Die klassische Aufbereitung dieser Akkus, insbesondere mit Hochtemperaturverfahren, ist energetisch aufw{\"a}ndig und f{\"u}hrt zudem nur zur partiellen R{\"u}ckgewinnung der Wertelemente, die dann auch erst durch weitere mechanische und chemische Prozesse wieder zu verwendbaren Materialien werden. Die vom Fachgebiet Aufbereitungstechnik der BTU mit verschiedenen Industriepartnern seit 2010 entwickelte Technologie verfolgt einen grundlegend anderen Ansatz. Ausgehend von einer hoch mechanisierten und teilweise automatisierten Demontage der Akkus k{\"o}nnen dabei die Einzelkomponenten weitgehend unzerst{\"o}rt und ohne thermische Sch{\"a}digung oder Verlust brennbarer und leicht fl{\"u}chtiger Anteile zur{\"u}ck gewonnen werden. F{\"u}r die Abtrennung der Kathodenbeschichtung von der Tr{\"a}gerfolie kommt nach der Zellendemontage eine hoch mechanisierte Nassaufbereitung zum Einsatz, bei der mittlerweile vollst{\"a}ndig auf den Einsatz von Chemikalien verzichtet werden kann. Das separierte NMC-Schwarzmaterial soll so aufbereitet werden, dass es zuk{\"u}nftig in Recyclat-Zellen f{\"u}r verschiedene Anwendungen genutzt werden kann. Dazu werden verschiedene Zerkleinerungs- und Sortiertechnologien getestet.}, language = {de} } @misc{MarkowskiAckerDuckeetal., author = {Markowski, Jens and Acker, J{\"o}rg and Ducke, Jana and Schelter, Matthias}, title = {Recovery and secondary use of Nickel-Manganese-Cobalt-Material from Cathodes of electric car traction batteries}, series = {59th Annual Conference of Metallurgists : emerging technologies in materials and metallurgical industries : COM 2020}, volume = {2020}, journal = {59th Annual Conference of Metallurgists : emerging technologies in materials and metallurgical industries : COM 2020}, publisher = {Canadian Institute of Mining, Metallurgy and Petroleum}, isbn = {978-1-926872-47-6}, abstract = {Automotive technology is increasingly determined by electric vehicles driven by high-performance lithium ion batteries (LIB). Li-ion batteries equipped with layered oxide cathodes, which are constituted by oxides of nickel, manganese and cobalt, are proven as storage devices that combine high electrical power, high cycling stability and compact dimensions. These batteries contain large amount of valuable elements, such as the cathodes consisting of cobalt and nickel, the electrode carrier foils consisting of copper and aluminium. Therefore, spent LIB's are valuable secondary resources. Thermal processing as the classical recycling-technology for LIB's is energy-intensive and allow only a partial recovery of some value elements. Scientists of the Brandenburg University of Technology (Germany) developed in collaboration with industrial partners (SME) a process, in which the complex system LIB is partly automated dismounted into its basic components. The core of this process is the separation of anodes and cathodes from each other and an almost complete recovery of the cathode material from the foil. The recovered cathode material has an enormous potential for a re-use in new LIB's. By a proper combination of separation and post-treatment the material has a quality that is close to virgin cathode material. Preliminary studies made on LIB's containing a fraction of recycled cathode material up to 50\% show an electrical performance comparable to LIB's made from virgin material.}, language = {en} } @misc{MarkowskiLohseWagner, author = {Markowski, Jens and Lohse, Anja and Wagner, Holger}, title = {Aggregate for the recovery of gold from thin coatings by hydro-biotechnological methods}, series = {Biomining´21, MEI Conferences, 1 Freeman Collins Drive, Trescobeas Road Falmouth, Cornwall, UK}, journal = {Biomining´21, MEI Conferences, 1 Freeman Collins Drive, Trescobeas Road Falmouth, Cornwall, UK}, editor = {Wills, Barry}, publisher = {MEI Conferences}, address = {Falmouth, UK}, abstract = {Together with industrial partners, a complex apparatus was developed at the Brandenburg Technical University Cottbus-Senftenberg, which can be used to decoat gold-bearing waste from PCB- produc-tion waste and contact stripes using biotechnological methods. As a result, a complete and separate recovery of the gold flakes and the carrier material copper with high purity is possible. The bioleaching process is done with iron and sulfur oxidizing bacteria, especially Acidithiobacillus ferrooxidans, Leptospirilum ferrooxidans and Acidithiobacillus thiooxidans. Compared to processes using inorganic acids, shorter leaching times can be achieved, partial regenera-tion and multiple use of the bioleaching solution is possible (more than 10 times with the same leach-ing solution). After optimizing the conditions a process time of only 60 hours was reached. The sepa-rated gold tinsel with a content of over 900 mg/g Au is then fed into a precious metal smelter. Due to the biological leaching and the resulting concentration of the gold components, only < 1 wt.\% of the waste containing precious metals has to be thermally treated.}, language = {en} }