Investigation of deep eutectic solvents as a reaction medium for metal chloride based chemical heat pumps

Download

index.pdf

Date

2019

Author

Gözde, Ezgi

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

321
views

169
downloads

Metal chlorides can react with gas phase ammonia and form complex compounds. Due to reversibility and high heat of reaction, these ionic reactions are attractive for the application of chemical heat pumps which can provide the ability to capture the rejected low-grade heat and to reuse it at increased temperature levels. The pressure and temperature interval of ammonia sorption into CaCl₂is suitable for heat upgrade of waste heat streams, geothermal energy and solar energy sources.However, heat and mass transfer limitation of the gas-solid phase is one of the major challenges. In order to overcome this challenge, in this thesis, the potential usage of the deep eutectic solvents(DES) as a reaction medium for the CaCl₂-NH3pair was studied. As DES, in different molar ratios,ZnCl2-ureaand ChCl-urea pairs were synthesized. From stability tests, it was found that ZnCl₂-ureaDES which has a maximum 30 days of a lifetime is significantly less stable than ChCl-urea DES which has a lifetime more than 6 months under ambient conditions. The solubilities of CaCl₂were determined as 3.7wt% and 5.3wt% for the ZnCl2-ureamolar ratio of 3.5:10 and 2.5:10 respectively. Ammonia sorption experiments revealed that higher amount of ammonia is absorbed into CaCl₂-ZnCl₂-ureasuspensionthan pure solid CaCl₂. Ammonia sorption takes place with a significant rate and extend in CaCl₂-ChCl-urea DES but much slower than the one observed for CaCl₂/ZnCl₂-urea samples.The desorption pressure-temperature equilibrium relationship exhibit more complex trend than the linear Clausius-Clapeyron equation because of the complex nature of sorption into CaCl₂/ZnCl₂-Urea mixture.

Subject Keywords

Solvents., Keywords: Deep Eutectic Solvents, Solubility of a Salt in DES, Chemical Heat Pumps.

URI

http://etd.lib.metu.edu.tr/upload/12624664/index.pdf
https://hdl.handle.net/11511/44501

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Application of semi conductor films over glass/ceramic surfaces and their low temperature photocatalytic activity Ersöz, Tuğçe İrfan; Karakaş, Gürkan; Department of Chemical Engineering (2009) Semiconductor metal oxides can be induced by light with proper wavelength resulting in oxidation and reduction reactions for the transformation of water and oxygen molecules into active radicals. With this method, it is possible to obtain self-cleaning surfaces and products having antimicrobial properties. The aim of this study is to develop semiconductor metal oxide thin films for multifunctional glass products and the characterization of photocatalytic self cleaning and antimicrobial properties. As semico...
Chemical vapor deposition of boron carbide Karaman, Mustafa; Özbelge, Önder; Department of Chemical Engineering (2007) Boron carbide was produced on tungsten substrate in a dual impinging-jet CVD reactor from a gas mixture of BCl3, CH4, and H2. The experimental setup was designed to minimise the effect of mass transfer on reaction kinetics, which, together with the on-line analysis of the reactor effluent by FTIR, allowed a detailed kinetic investigation possible. The phase and morphology studies of the products were made by XPS, XRD,micro hardness and SEM methods. XPS analysis showed the existence of chemical states attrib...
Modelling of non-uniform DC driven glow discharge in argon gas Rafatov, İsmail; BILIKMEN, S. (Elsevier BV, 2007-07-16) Physical properties of non-uniform DC-driven glow discharge in argon at pressure 1 torr are analyzed numerically. Spatially two-dimensional axial-symmetric model is based on the diffusion-drift theory of gas discharge. Results presented compare favorably with the classic theory of glow discharges and exhibit good agreement with the experimental result. Comparison with the result of spatially one-dimensional model is performed. (c) 2007 Elsevier B.V. All fights reserved.
ELECTROLYSIS OF MGCL2 WITH A TOP INSERTED ANODE AND AN MG PB CATHODE GUDEN, M; Karakaya, İshak (Springer Science and Business Media LLC, 1994-08-01) High energy consumption in the production of magnesium by molten salt electrolysis is mainly due to the recombination of magnesium and chlorine. The large interelectrode distance used, in conventional techniques, to reduce the extent of 'back reaction', results in a significant potential drop. A laboratory cell that enables the operation with smaller interelectrode distance and easy separation of electrode products has been used to study electrolytic magnesium production. The cell features a top inserted gr...
Application of the Pippard relations to ammonia near the melting point Yurtseven, Hasan Hamit (1999-09-01) This study gives our application of the Pippard relations to the ammonia near its melting point. The Pippard relations between the specific heat C-P, the thermal expansivity alpha(P) and the isothermal compressibility kappa(T), have been established for the ammonia near its melting point. We have obtained that the Pippard relations are valid for the ammonia. We give here an evidence that on the basis of the experimental data the critical transition in this system near its melting point can be considered as ...

Citation Formats

E. Gözde, “Investigation of deep eutectic solvents as a reaction medium for metal chloride based chemical heat pumps,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Chemical Engineering., Middle East Technical University, 2019.