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Papers by G. Cacciola
International Journal of Hydrogen Energy, 1993
In this paper the flow diagram for a high-temperature chemical heat pump (HTCHP) based on the rev... more In this paper the flow diagram for a high-temperature chemical heat pump (HTCHP) based on the reversible cyclohexane dehydrogenation-benzene hydrogenation reactions is analyzed. The peculiarity of this diagram is a multipurpose use of hydrogen-permeable membranes. A thermodynamic analysis of the proposed flow diagram is undertaken in order to examine the influence of different factors on the coefficient of performance of the heat pump and on the pressure in the dehydrogenation reactor. It is shown that the new flow diagram with the hydrogenpermeable membranes allows us to improve the performance of the HTCHPs and to extend the field of their practical application.
International Journal of Hydrogen Energy, 2009
ABSTRACT In this paper, a novel 3D flexible tool for simulation of metal hydrides-based (LaNi5) h... more ABSTRACT In this paper, a novel 3D flexible tool for simulation of metal hydrides-based (LaNi5) hydrogen storage tanks is presented. The model is Finite Element-Based and considers coupled heat and mass transfer resistance through a non-uniform pressure and temperature metal hydride reactor. The governing equations were implemented and solved using the COMSOL Multiphysics simulation environment. A cylindrical reactor with different cooling system designs was simulated. The shortest reactor fill time (15min) was obtained for a cooling design configuration consisting of twelve inner cooling tubes and an external cooling jacket. Additional simulations demonstrated that an increase of the hydride thermal conductivity can further improve the reactor dynamic performance, provided that the absorbent bed is sufficiently permeable to hydrogen.
Studies in Surface Science and Catalysis - STUD SURF SCI CATAL, 1999
ABSTRACT
Reaction Kinetics and Catalysis Letters, 1998
Journal of Power Sources, 2001
This paper reports the state of art on fuel cells technology, outlines the most significant resul... more This paper reports the state of art on fuel cells technology, outlines the most significant results reached all over the world and summarises the strategies developed by researchers and producers to get the commercialisation of these systems. In particular, the authors have examined three potential application fields for fuel cells: (i) stationary power plant for electricity production; (ii) portable power applications; (iii) electric vehicles.
International Journal of Energy Research, 1987
Applied Thermal Engineering, 2002
In this communication a family of new working materials, so called selective water sorbents, is p... more In this communication a family of new working materials, so called selective water sorbents, is presented for sorption air conditioning. These materials are composites``hygroscopic salt inside porous matrix with open pores'' and possess intermediate behaviour between solid adsorbents, salt hydrates and liquid absorbents, so that their water sorption properties can be controllably modi®ed by varying (a) porous structure of the host matrix, (b) chemical nature of the impregnated salt and (c) the amount of the salt inside the pores. For these materials the water sorption equilibrium and speci®c heat have been measured in a wide temperature and uptake range. This study shows that composites based on CaCl 2 and LiBr as impregnated salts and dierent micro-and mesoporous silica gels as host matrices are able to absorb up to 0.75 g H 2 O per 1 g of the dry sorbent. After presentation of sorption equilibrium curves, the thermodynamic performance for their utilisation in heat pump and refrigeration systems, is calculated. The results show that these new materials can be operated with cycles whose maximum temperature is about 95°C (for cooling) and 140°C (for heating) that are lower than those for other pairs known so far. The values of coecient of performance are considerably higher than those reported for silica gel/water system at the same temperature of the heat source. Ó
Journal of Chemical and Engineering Data - J CHEM ENG DATA, 1995
ABSTRACT
International Journal of Hydrogen Energy, 1993
In this paper the flow diagram for a high-temperature chemical heat pump (HTCHP) based on the rev... more In this paper the flow diagram for a high-temperature chemical heat pump (HTCHP) based on the reversible cyclohexane dehydrogenation-benzene hydrogenation reactions is analyzed. The peculiarity of this diagram is a multipurpose use of hydrogen-permeable membranes. A thermodynamic analysis of the proposed flow diagram is undertaken in order to examine the influence of different factors on the coefficient of performance of the heat pump and on the pressure in the dehydrogenation reactor. It is shown that the new flow diagram with the hydrogenpermeable membranes allows us to improve the performance of the HTCHPs and to extend the field of their practical application.
International Journal of Hydrogen Energy, 2009
ABSTRACT In this paper, a novel 3D flexible tool for simulation of metal hydrides-based (LaNi5) h... more ABSTRACT In this paper, a novel 3D flexible tool for simulation of metal hydrides-based (LaNi5) hydrogen storage tanks is presented. The model is Finite Element-Based and considers coupled heat and mass transfer resistance through a non-uniform pressure and temperature metal hydride reactor. The governing equations were implemented and solved using the COMSOL Multiphysics simulation environment. A cylindrical reactor with different cooling system designs was simulated. The shortest reactor fill time (15min) was obtained for a cooling design configuration consisting of twelve inner cooling tubes and an external cooling jacket. Additional simulations demonstrated that an increase of the hydride thermal conductivity can further improve the reactor dynamic performance, provided that the absorbent bed is sufficiently permeable to hydrogen.
Studies in Surface Science and Catalysis - STUD SURF SCI CATAL, 1999
ABSTRACT
Reaction Kinetics and Catalysis Letters, 1998
Journal of Power Sources, 2001
This paper reports the state of art on fuel cells technology, outlines the most significant resul... more This paper reports the state of art on fuel cells technology, outlines the most significant results reached all over the world and summarises the strategies developed by researchers and producers to get the commercialisation of these systems. In particular, the authors have examined three potential application fields for fuel cells: (i) stationary power plant for electricity production; (ii) portable power applications; (iii) electric vehicles.
International Journal of Energy Research, 1987
Applied Thermal Engineering, 2002
In this communication a family of new working materials, so called selective water sorbents, is p... more In this communication a family of new working materials, so called selective water sorbents, is presented for sorption air conditioning. These materials are composites``hygroscopic salt inside porous matrix with open pores'' and possess intermediate behaviour between solid adsorbents, salt hydrates and liquid absorbents, so that their water sorption properties can be controllably modi®ed by varying (a) porous structure of the host matrix, (b) chemical nature of the impregnated salt and (c) the amount of the salt inside the pores. For these materials the water sorption equilibrium and speci®c heat have been measured in a wide temperature and uptake range. This study shows that composites based on CaCl 2 and LiBr as impregnated salts and dierent micro-and mesoporous silica gels as host matrices are able to absorb up to 0.75 g H 2 O per 1 g of the dry sorbent. After presentation of sorption equilibrium curves, the thermodynamic performance for their utilisation in heat pump and refrigeration systems, is calculated. The results show that these new materials can be operated with cycles whose maximum temperature is about 95°C (for cooling) and 140°C (for heating) that are lower than those for other pairs known so far. The values of coecient of performance are considerably higher than those reported for silica gel/water system at the same temperature of the heat source. Ó
Journal of Chemical and Engineering Data - J CHEM ENG DATA, 1995
ABSTRACT