Thermodynamic Modeling of Hydrogen Storage Capacity in Mg-Na Alloys

Thermodynamic modeling of the H-Mg-Na system is performed for the first time in this work in order to understand the phase relationships in this system. A new thermodynamic description of the stable NaMgH3 hydride is performed and the thermodynamic models for the H-Mg, Mg-Na, and H-Na systems are reassessed using the modified quasichemical model for the liquid phase. The thermodynamic properties of the ternary system are estimated from the models of the binary systems and the ternary compound using CALPHAD technique. The constructed database is successfully used to reproduce the pressure-composition isotherms for MgH2 + 10 wt.% NaH mixtures. Also, the pressure-temperature equilibrium diagram and reaction paths for the same composition are predicted at different temperatures and pressures. Even though it is proved that H-Mg-Na does not meet the DOE hydrogen storage requirements for onboard applications, the best working temperatures and pressures to benefit from its full catalytic role are given. Also, the present database can be used for thermodynamic assessments of higher order systems

Assessment of Barriers to Wind Energy Development Using Analytic Hierarchy Process

Despite the vast potential of wind energy, it has yet to be implemented widely in Bangladesh. Several barriers play major roles in obstructing the wind energy sector’s development in Bangladesh. Hence, it is necessary to identify these barriers to progress this sector’s growth. The analytic hierarchy process (AHP) is a multi-criteria decision-making method that can rank alternatives by considering multiple factors. It is a valuable tool for complex decision-making problems with multiple criteria, and their relationships must be clarified. So, in this analysis, AHP is used to rank the barriers related to wind energy development in Bangladesh. First, six main barriers and eighteen sub-barriers have been identified from a detailed and comprehensive literature review. The main barriers are categorized into technical, administrative, policy and political, economic, social, and geographic. After that, a questionnaire was sent to experts to obtain their opinions on these barriers. Based on the analysis, it was found that, with a weighted score of 0.46, technical barriers were the most significant ones. Administrative barriers ranked second with a weighted score of 0.21, and social barriers ranked last with a weighted score of 0.03. Among the sub-barriers, risks associated with technology were found to be the most significant, while land use conflict was found to be the least significant. Finally, several recommendations are provided to overcome the wind energy barriers in Bangladesh. The findings of this study can help policymakers and stakeholders develop strategies to overcome the barriers to wind energy development in Bangladesh