Performance analysis of the sulfur cycle for nuclear-hydrogen production

Abstract

The goal of this study is to analyze the performance of the sulfur cycle for nuclear-hydrogen production. Among the whole steps of the Westinghouse sulfur cycle, this study focused on the 2 steps, “Vaporization” and “Decomposition” processes which are coupled with the nuclear reactor, VHTR (Very High Temperature Reactor). In the present study, the main focus has been on the decomposition rate and correlation functions about VLE data. After reproduction of the previous study, we proposed the modified and developed correlation functions. Based on those correlations, we established the system analyzing code $\mdash Gamma$ S $\mdash$ by Matlab. In decomposition process, the range of temperature was about 850 - 1100℃. Pressure range was from 1 bar to 90bar. In vaporization process, the ranges of temperature and pressure are 0-350℃, 1-90bar, respectively. The suggested correlation functions are derived from the inverse first order partial pressure equation. So they contained the physical meaning, furthermore the relative deviation errors were reduced than previous correlation. And in case of decomposition model, we combined the equilibrium and transient conversion concepts. So the combined conversion yield concept corresponded with experiment. Conclusively, this present study recommends the following model and correlation functions. 1. Vaporization a) Boiling temperature: $\frac{1}{T_{boil}}=C+D\mdot(log_{10}P_{tot})$ b) Partial pressure : $log_{10}P_i=A_i+\frac{B_i}{T}$

2. Decomposition a) Combined conversion concepts : $X=X_e(1-exp(-k\mdott))$ b) Catalysts beds packed effect : $\frac{dp}{L_{decom}}=\frac{150\mu(1-\varepsilon)^2V_s}{\varepsilon^3{D_p}^{2}}+\frac{1.75\low(1-\varepsilon){V_s}^{2}}{{\varepsilon}^3D_p}$