Thermal decomposition kinetic of salt hydrates for heat storage systems

2015 ◽  
Vol 154 ◽  
pp. 447-458 ◽  
Author(s):  
Armand Fopah Lele ◽  
Frédéric Kuznik ◽  
Holger U. Rammelberg ◽  
Thomas Schmidt ◽  
Wolfgang K.L. Ruck
Author(s):  
Armand Fopah Lele ◽  
Fréderic Kuznik ◽  
Holger Urs Rammelberg ◽  
Thomas Schmidt ◽  
Wolfgang K. L. Ruck

Heat storage systems using reversible chemical solid-fluid reactions to store and release thermal energy operates in charging and discharging phases. During last three decades, discussions on thermal decomposition of several salt-hydrates were done (experimentally and numerically) [1,2]. A mathematical model of heat and mass transfer in fixed bed reactor for heat storage is proposed based on a set of partial differential equations (PDEs). Beside the physical phenomena, the chemical reaction is considered via the balances or conservations of mass, extent conversion and energy in the reactor. These PDEs are numerically solved by means of the finite element method using Comsol Multiphysics 4.3a. The objective of this paper is to describe an adaptive modeling approach and establish a correct set of PDEs describing the physical system and appropriate parameters for simulating the thermal decomposition process. In this paper, kinetic behavior as stated by the ICTAC committee [3] to understand transport phenomena and reactions mechanism in gas and solid phases is taking into account using the generalized Prout-Tompkins equation with modifications based on thermal analysis experiments. The model is then applied to two thermochemical materials CaCl2 and MgCl2 with experimental activation energies and a comparison is made with TGA-DSC measurement results.


2008 ◽  
Vol 24 (06) ◽  
pp. 1090-1094
Author(s):  
MA Wei ◽  
◽  
◽  
WANG Su ◽  
CUI Ji-Ping ◽  
...  

2012 ◽  
Vol 182-183 ◽  
pp. 1575-1580 ◽  
Author(s):  
Juan Wang ◽  
Da Bin Liu ◽  
Xin Li Zhou

The certain nitrate ester explosive has been tested by TG at the heating rates of 10, 15, 20, 25K•min-1. Basing on the TG experiment results the thermal decomposition activation energy has been calculated by the methods of Ozawa, KAS and iteration. And the thermal decomposition mechanism function of the explosive with 38 kinds of dynamic function was deduced by the method of integration. The results show that the thermal decomposition mechanism of the nitrate ester is chemical reaction mechanism. The thermal decomposition kinetic parameters such as average activation energy Ea and pre-exponential factor A are 133.23×103 J•mol-1 and 3.191×107 s-1 respectively.


2010 ◽  
Vol 152-153 ◽  
pp. 184-191 ◽  
Author(s):  
Dong Lian Chen ◽  
Shao Mei Ma ◽  
Hui Cheng Yu ◽  
Ai Qun Yuan ◽  
An Ping Liao ◽  
...  

Thermal decomposition kinetic reaction parameters of KZn2(PO4)(HPO4) was investigated by non-isothermal measurement used in a multivariate non-linear regression analysis. The anticorrosive performance of the phosphate extracts in different pH 3.5% NaCl was studied by polarization and open circuit potential measurements. Kinetics analysis shows that the decomposition of KZn2(PO4)(HPO4) acts as a double-step reaction of : a n order autocatalytic reaction (Cn) with n =1.0791, E1 = 365.06 kJ/ mol, A1 =8.69×1022s−1 is followed by a expended Prout-Tompkins reaction (Bna) with n=2.6548, E2 = 390.91 kJ /mol, A2 = 5.37×1024 s−1. In different pH 3.5% NaCl extracts, KZn2(PO4)(HPO4) functions as a cathodic inhibitor on steel and is even superior to other phosphates in efficiency. The inhibiting efficiency of the pigments on steel decrease in the order: KZn2(PO4)(HPO4) > aluminum zinc phosphate > zinc phosphate ≧ aluminum triphosphate


2014 ◽  
Vol 589 ◽  
pp. 270-277 ◽  
Author(s):  
I. Ben Talouba ◽  
N. Bensahlam ◽  
H. Medjkoune ◽  
N. Mouhab ◽  
L. Balland ◽  
...  

Author(s):  
Fatemeh Najarnia ◽  
Fatemeh Ahmadpoor ◽  
Samaneh Sahebian ◽  
Jacqueline A. Johnson ◽  
Saeed Kamali ◽  
...  

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