ABSTRACT
To predict real-time performance of metal hydride-based systems, La0.9Ce0.1Ni5 and LaNi4.7Al0.3 alloys are opted to investigate the influence of operating temperature and supply pressure on absorption kinetics. For the same, the pressure ratio is varied from 1.5 to 4 by keeping the temperature constant. Later, the operating temperature is varied (20–80°C) for the above range of pressure ratio. The study revealed that the absorption kinetics of metal hydrides is substantially influenced by operating temperature and supply pressure. It is observed that with an increase in pressure ratio (1.5, 2, 2.5, 3, and 3.5), the hydrogen supply pressure increases (9.75, 13, 16.25, 19.5, and 22.75), which creates high driving potential consequently results in faster reaction rates. However, increase in operating temperature (20°C and 40°C) at constant supply pressure (25 bar) results in slower reaction rates due to decrease in driving potential because the equilibrium pressure of La0.9Ce0.1Ni5 is higher at high temperature. The similar effect is obtained for LaNi4.7Al0.3. The experimental measurements are carried out using an in-house Sievert’s apparatus and are compared with numerical results obtained through a mathematical model that results in good agreement.
Nomenclature
Cp | = | Specific heat (kJ/kg K) |
E | = | Activation energy; (kJ/mol of H2) |
R | = | Gas constant; (kJ/kmol K of H2) |
T | = | Temperature; (K) |
V | = | Volume; (m3) |
fa | = | Fraction absorbed |
mi,s,a | = | Mass of hydrogen in supply volume; (g) |
mi,t,a | = | Mass of hydrogen after absorption at any time t; (g) |
mt,a | = | Mass of hydrogen absorbed at any time t; (g) |
Vs | = | Supply volume; (m3) |
p | = | Pressure; (bar) |
ΔH | = | Reaction enthalpy; (kJ/mol) |
ΔS | = | Reaction entropy; (kJ/mol K) |
Pmid/Peq | = | Equilibrium pressure; (bar) |
Pr | = | Pressure ratio |
Ps | = | Supply pressure (bar) |
x | = | Hydrogen concentration |
λ | = | Thermal conductivity, W/m K |
φ, φ0 | = | Slope factors |
ρ | = | Density (kg/m3) |
β | = | Hysteresis factor |
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Manoj S. Choudhari
Manoj Shyamrao Choudhari is working as an Assistant Professor in the Department of Mechanical Engineering at Tulsiramji Gaikwad Patil College of Engineering and Technology, Nagpur, Maharashtra, India. His areas of research are Hydrogen Energy, Solar Energy Storage, CO2 Capture and Sequestration, Renewable Energy, Phase Change Material based Thermodynamic Systems and Computational Fluid Dynamics. He has completed his PhD from the Vellore Institute of Technology, Vellore, India and M-Tech from Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal, India. He has more than 4 years of experience in the field of energy technologies. He has published several research articles (5+) in international peer-reviewed journals. In addition, he has published several conference proceedings (3+), book chapters (02) and patents (02).
Josy James
Josy James is persuing PhD in the Department of Mechanical Engineering at National Institute of Technology Calicut, India. His areas of research are Hydrogen Energy, Renewable Energy, Heat Transfer, Refrigeration, and Computational Fluid Dynamics. He has completed his MTech in Thermal Engineering from Teerthanker Mahaveer University College of Engineering, Moradabad, Uttar Pradesh, India. He has completed Bachelor of Engineering from Chhattisgarh Swami Vivekananda Technical University, Bhilai, India. He has 2 years of experience in the field of energy technology.
Man Mohan
Man Mohan currently working as postdoctoral researcher at AJOU university, Korea. He holds a Ph.D. in Mechanical Engineering from VIT University in Vellore, India. He completed his master's in Thermal Engineering from CSVTU Bhilai, India. Also his bachelor’s degree in mechanical engineering was obtained from CSVTU Bhilai India. He has contributed to few publications focusing on various aspects of energy storage, thermodynamics, and heat transfer, including the prospects of hydrogen storage, solar photovoltaic modules using phase change materials, and hybrid nano-enhanced phase change materials for thermal energy storage applications. He has also conducted studies on sorption heat transformers, metal hydride-based cooling and heat transformation systems, and multi-stage multi-effect sorption thermodynamic systems.
Vinod Kumar Sharma
Vinod Kumar Sharma is working as an Assistant Professor in the Department of Mechanical Engineering at National Institute of Technology Calicut, India. His areas of research are Hydrogen Energy, CO2 Capture and Sequestration, Renewable Energy, Heat Transfer, Refrigeration and Air-Conditioning, and Computational Fluid Dynamics. He has completed his PhD from the Indian Institute of Technology Indore, India and MTech from Visvesaraya National Institute of Technology Nagpur, India. He has more than 10 years of experience in the field of energy technologies. He has guided 4 PhD scholars in the field of energy systems and 4 on going. He has completed several sponsored and consultancy projects. He has published several research articles (40+) in international peer-reviewed journals. In addition, he has published several conference proceedings (20+), book chapters (04) and patents (02).
E. Anil Kumar
E. Anil Kumar is currently working as Professor in the Department of Mechanical Engineering and Dean Sponsored Research and Consultancy at IIT Tirupati. He obtained his PhD Degree from the Department of Mechanical Engineering, IIT Madras. Later he worked as Assistant professor and Associate Professor in the Discipline of Mechanical Engineering at IIT Indore. He also served the Institute as Associate Dean of Academic Affairs. He is founding Head of Mechanical Engineering Departments at two IIT’s i.e. IIT Indore and IIT Tirupati. His research interests are measurement of thermodynamic and thermophysical properties of solid-state hydrogen storage materials, Thermal energy storage, carbon dioxide capture and sorption heating and cooling systems. He has published more than hundred papers in peer reviewed international journals and proceedings of international and national conferences. He executed many sponsored projects. He has guided 7 PhD and 1 MS Scholars and currently 4 PhDs are working under his guidance. He is editorial board member of Wiley Journal “Energy Storage” and Guest editor for the Journal of Thermal Science and Engineering Progress.
Prem Kumar Chaurasiya
Prem Kumar Chaurasiya is working as an Assistant Professor in Department of Mechanical Engineering, with additional charge of NAAC, NIRF & NBA Coordinator at Bansal Institute of Science and Technology, Bhopal, India. His nature of experience is Teaching and Research (Science, Technology, Society, and Sustainable Development). His areas of specializations are; Energy Technology, Renewable Energy, Solar Energy Applications, Energy Economics, Heat Transfer, and Environmental Issues. He has completed four research funded projects in these areas. He has more than 5 years of experience in the field of energy technology. He has published papers in International peer-reviewed journals like Renewable Energy, Fuel, Energy Conversion and Management. His paper is being cited in all the reputed relevant journals. He is an author of 2 books. He has been granted 4 Patent. Dr. Prem has also served as a Managing Guest Editor for Materials Today Proceeding (Elsevier) and Leading Guest Editor for Lecture Notes in Mechanical Engineering (Springer). He is also an active reviewer for various international journal of repute. He has also organized International Conference entitled “Technology Innovation in Mechanical Engineering- TIME 2021.