% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @PHDTHESIS{Qi:989675, author = {Qi, Jia}, othercontributors = {Spatschek, Robert and Müller, Michael and Schneider, Jochen M.}, title = {{T}hermodynamics of salt system: ${L}i^+$, ${K}^+$, ${N}a^+$ // ${C}l^-$, ${CO}_3$ $^{2-}$.}, school = {Rheinisch-Westfälische Technische Hochschule Aachen}, type = {Dissertation}, address = {Aachen}, publisher = {RWTH Aachen University}, reportid = {RWTH-2024-06931}, pages = {1 Online-Ressource : Illustrationen}, year = {2024}, note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen University; Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2024}, abstract = {In this work, a new thermodynamic database of the Li+, Na+, K+//Cl-, CO32- system was generated using the Calphad method with FactSage. After collecting and analyzing the available thermodynamic data in the literature, experiments were designed to improve the comprehensiveness of the new database. Differential Thermal Analysis (DTA) and high temperature X-ray diffraction (HTXRD) were used to determine the phase transition temperatures. Different types of Differential Scanning Calorimetry (DSC) were used to investigate the heat capacity of pure salts and intermediate compounds. The controversial solid-solid phase transition of Li2CO3 was proved to be caused by impurities. The accuracy of the heat capacity of Li2CO3, LiKCO3 was improved, the heat capacity of LiNaCO3 was measured for the first time. The eutectic temperature of the K2CO3-KCl system was measured, the solid solubility in the K2CO3-Li2CO3 system based on K2CO3 was checked. The phase diagram of the subsystem Li2CO3-Na2CO3 was further completed, three solid solution phases based on the three solid modifications of pure Na2CO3 were determined. For the reciprocal systems Li+, K+//Cl-, CO32- and Li+, Na+//Cl-, CO32-, phase diagrams of diagonal systems Li2CO3-K2Cl2, K2CO3-Li2Cl2, Li2Cl2-Na2CO3 and Li2CO3-Na2Cl2 were measured. The Gibbs energy data of stoichiometric compounds (Li2CO3, LiKCO3 and LiNaCO3) and the Gibbs energy functions of the solutions (liquid and solid solutions) of the mentioned systems were reassessed according to the literature and own experimental data for the new database. Mainly based on the literature data, the Gibbs energy of pure salt LiCl, the Gibbs energy of the liquid phase of binary LiCl-NaCl, LiCl-KCl, LiCl-Li2CO3, KCl-K2CO3, NaCl-Na2CO3 systems and the reciprocal system Na+, K+//Cl-, CO32- and the ternary systems Li+, K+, Na+//Cl- and Li+, K+, Na+//CO32- were reassessed. A new database was developed, which can calculate and predict the thermodynamic properties of the whole system more precisely and reliably.}, cin = {525820 / 520000}, ddc = {620}, cid = {$I:(DE-82)525820_20160614$ / $I:(DE-82)520000_20140620$}, pnm = {PCM-Screening: Evaluierung eutektischer Gemische f. d. Einsatz als PCM: thermodynamische Modellierung und experimentelle Methoden. Teilvorhaben: Thermochemie wasserfreier Salzsysteme für PCM (03ET1441D) / Verbundvorhaben: PCM-Screening-2 - Evaluierung von Salzsystemen für den Einsatz als PCM: thermodynamische Modellierung und experimentelle Methoden - 2; Teilvorhaben: Thermochemie wasserfreier Salzsysteme für PCM (01GW0623)}, pid = {G:(BMWi)03ET1441D / G:(BMWK)01GW0623}, typ = {PUB:(DE-HGF)11}, doi = {10.18154/RWTH-2024-06931}, url = {https://publications.rwth-aachen.de/record/989675}, }