Most thermochemical cycles require complex thermal processes at very high temperatures, which restrict the production and the use of hydrogen on a large scale. Recently, thermochemical cycles producing hydrogen at relatively low temperatures have been developed in order to be competitive with other kinds of energies, especially those of fossil origin. The low temperatures required by those cycles allow them to work with heats recovered by thermal, nuclear and solar power plants. In this work, a new thermochemical cycle is proposed. This cycle uses the chemical elements Magnesium-Chlorine (Mg-Cl) to dissociate the water molecule. The configuration consists of three chemical reactions or three physical steps and uses mainly thermal energy to achieve its objectives. The highest temperature of the process is that of the production of hydrochloric acid, HCl, estimated between 350-450℃. A thermodynamic analysis was performed according to the first and second laws by using Engineering Equation Solver (EES) software and the efficiency of the proposed cycle was found to be 12.7%. In order to improve the efficiency of this cycle and make it more competitive, an electro-thermochemical version should be studied.

The purpose of this work is to study sand grains transport for the saltation mode. A numerical simulation approach is adopted with the introduction of a density distribution function. That aims to quantify the transported sand grains, according to the continuum theory. Making a prediction model for transported quantities. In this study, a fine sand grain size is taken into consideration as d=0. 295mm. The inlet wind velocities vary between 8 &18 m/s. The simulation results of sand flux are validated using previous experimental results. The mean horizontal velocity profiles are shown and discussed. It is noted that the sand flux can be described as a Gaussian function which is in good agreement with the experimental results in tunnels for the fine sand groups. This results lead to deduce the lift-off velocity and incident angles profiles distribution. From the sand-coupled wind velocity profile; it can be found that the wind velocity profile near to the surface is modified from logarithmic to a linear function. The variation of the turbulent kinetic energy with increasing wind velocity is further discussed. Finally the energy dissipation is shown. This model will find application in studies of saltation mode on both Earth and Mars.