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Prof. Alberto Coronas is currently professor of thermal engineering in the Department of Mechanical Engineering at the Rovira i Virgili University, Tarragona, Spain, and Head of the Research Group on Applied Thermal Engineering (CREVER). He studied physics at the University of Valencia (1971-1974) and the University of Barcelona (1974-1976) where he majored in industrial physics. In 1983, he received his PhD in Physics from the University of Barcelona. Prof. Coronas began his research into absorption heat pumps during a postdoctoral stay under the supervision of Prof. Robert Bugarel at the Ecole Nationale Supérieure d’Ingénieurs en Génie Chimique (Toulouse, France). His research activity covers the field of absorption technology for industrial refrigeration and heat pumps, heat transfer and thermophysical properties of new working mixtures, and polygeneration technologies. He has supervised approximately 35 PhD theses and published more than 150 referenced technical publications.
The density and refractive index were experimentally determined for binary mixtures of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate throughout the ionic liquid mass fraction range, at atmospheric pressure and various temperatures between 293.15 K and 323.15 K. The refractive index was measured at five wavelengths between 589.2 nm and 935 nm. From the experimental data on density, volumetric properties such as the excess molar volume and thermal expansion coefficient were calculated. The excess molar volume was negative throughout the ionic liquid mass fraction range and its magnitude decreased with temperature. From the experimental data on the refractive index, the deviation in the refractive index and its coefficients of concentration, temperature and chromatic dispersion were obtained. The values of the deviation in the refractive index were positive and decreased with temperature. In order to simultaneously investigate the dependence of the refractive index on concentration, temperature and wavelength, we correlated the experimental data with a two-term Cauchy equation. Furthermore, a comparative study of 11 refractive index mixing rules was performed to assess their prediction ability. More advanced mixing rules do not lead to any improvement in comparison with the simple linear mixing rule (Arago-Biot) for estimating refractive index and the concentration contrast factor of the mixture studied. The results are expected to be useful for tuning the properties of an ionic liquid by adding water or selecting the temperature or optical region.
R. Rives; A. Mialdun; V. Yasnou; V. Shevtsova; A. Coronas. Density, refractive index, and derived properties of binary mixtures of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate. The Journal of Chemical Thermodynamics 2021, 160, 106484 .
AMA StyleR. Rives, A. Mialdun, V. Yasnou, V. Shevtsova, A. Coronas. Density, refractive index, and derived properties of binary mixtures of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate. The Journal of Chemical Thermodynamics. 2021; 160 ():106484.
Chicago/Turabian StyleR. Rives; A. Mialdun; V. Yasnou; V. Shevtsova; A. Coronas. 2021. "Density, refractive index, and derived properties of binary mixtures of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate." The Journal of Chemical Thermodynamics 160, no. : 106484.
The use of waste heat or low-exergy heat sources represents a strategic opportunity to reduce the environmental footprint and operation cost of industrial processes. The absorption heat transformer, also known as absorption heat pump type II, is a thermal machine which can boost the temperature of a heat flow by using a negligible amount of electrical power. However, owing to the lack of established technical knowledge and the absence of comprehensive recordings of successful heat transformer applications, the feasibility and reliability of absorption heat transformers have been questioned and the diffusion of this technology remained limited. Therefore, in this paper, all the industrial applications of the absorption heat transformer that are recorded in previous literature and yet unpublished reports are presented and discussed. In addition to literature research, intense knowledge exchange with three leading manufacturers of absorption heat transformers gave an accurate perspective on the technological level of commercial products and operative installations. It is shown that between 1981 and 2019, 48 absorption heat transformers have been installed in 42 plants with a total capacity of ≈134MW. Two main implementation periods, separated by 25 years of infrequent heat transformer installations, have been recognised. More than 74% of the installations were in Asia. Approximately 61% of the heat transformer installations were applied into the chemical industry. Therefore, through the analysis of the technical challenges and their solutions, along with related economical aspects of heat transformer installations, the effective state-of-the-art of this technology is presented and discussed.
Falk Cudok; Niccolò Giannetti; José L. Corrales Ciganda; Jun Aoyama; P. Babu; Alberto Coronas; Tatsuo Fujii; Naoyuki Inoue; Kiyoshi Saito; Seiichi Yamaguchi; Felix Ziegler. Absorption heat transformer - state-of-the-art of industrial applications. Renewable and Sustainable Energy Reviews 2021, 141, 110757 .
AMA StyleFalk Cudok, Niccolò Giannetti, José L. Corrales Ciganda, Jun Aoyama, P. Babu, Alberto Coronas, Tatsuo Fujii, Naoyuki Inoue, Kiyoshi Saito, Seiichi Yamaguchi, Felix Ziegler. Absorption heat transformer - state-of-the-art of industrial applications. Renewable and Sustainable Energy Reviews. 2021; 141 ():110757.
Chicago/Turabian StyleFalk Cudok; Niccolò Giannetti; José L. Corrales Ciganda; Jun Aoyama; P. Babu; Alberto Coronas; Tatsuo Fujii; Naoyuki Inoue; Kiyoshi Saito; Seiichi Yamaguchi; Felix Ziegler. 2021. "Absorption heat transformer - state-of-the-art of industrial applications." Renewable and Sustainable Energy Reviews 141, no. : 110757.
This paper presents an experimentally validated, dynamic model of a hybrid liquid desiccant system. For this purpose, we developed new components for the air-solution contactors, which are of the non-adiabatic falling-film type with horizontal tubes (made of improved polypropylene) and the solution tanks. We also provide new experimental correlations for both the tube-solution heat transfer coefficient and the mass transfer coefficient on the airside as a function of the air velocity. To validate the model, the results obtained from the dynamic simulations were compared with those obtained by monitoring a demonstration unit installed in a sports center in Taipei (Taiwan). Once validated, the model was used to perform a sensitivity analysis at different operational conditions, such as the inlet water temperatures in the air-solution contactors and the LiCl mass fraction at which the system operates. The results of the sensitivity analysis were used to optimize the seasonal performance in terms of comfort and energy required by the system. Compared with a conventional air-handling unit that controls air temperature and humidity, the annual energy savings of the liquid desiccant systems are 17%.
Juan Prieto; Antonio Atienza-Márquez; Alberto Coronas. Modeling and Dynamic Simulation of a Hybrid Liquid Desiccant System with Non-Adiabatic Falling-Film Air-Solution Contactors for Air Conditioning Applications in Buildings. Energies 2021, 14, 505 .
AMA StyleJuan Prieto, Antonio Atienza-Márquez, Alberto Coronas. Modeling and Dynamic Simulation of a Hybrid Liquid Desiccant System with Non-Adiabatic Falling-Film Air-Solution Contactors for Air Conditioning Applications in Buildings. Energies. 2021; 14 (2):505.
Chicago/Turabian StyleJuan Prieto; Antonio Atienza-Márquez; Alberto Coronas. 2021. "Modeling and Dynamic Simulation of a Hybrid Liquid Desiccant System with Non-Adiabatic Falling-Film Air-Solution Contactors for Air Conditioning Applications in Buildings." Energies 14, no. 2: 505.
Absorption chillers require precise models for their control and optimization. The present work analyzes the behavior of a 10-kW absorption chiller by means of four different methods that use the external fluid temperatures to situate the machine operating conditions, either through a characteristic temperature difference or through the COPcarnot. The studied models are of different physical insight levels: a semi-empirical method (the characteristic equation method), two empirical methods (the adapted characteristic equation method and the Carnot function model), and a thermodynamic model, here called the “effectiveness model,” based on thermal and mass effectivenesses. The COPcarnot is used for the first time as a common parameter to situate the results from the different models and the effectivenessses of the components. Different from previous models presented in the literature, the proposed effectiveness model is able to account for the non-equilibrium conditions of the solution with the vapor phase at the inlet and outlet of the sorption exchangers. Therefore, owing to a better understanding of the internal machine behavior, it allowed for the identification of thermal and electric COP improvement opportunities.
Amín Altamirano; Nolwenn Le Pierrès; Benoit Stutz; Alberto Coronas. Performance characterization methods for absorption chillers applied to an NH3-LiNO3 single-stage prototype. Applied Thermal Engineering 2020, 185, 116435 .
AMA StyleAmín Altamirano, Nolwenn Le Pierrès, Benoit Stutz, Alberto Coronas. Performance characterization methods for absorption chillers applied to an NH3-LiNO3 single-stage prototype. Applied Thermal Engineering. 2020; 185 ():116435.
Chicago/Turabian StyleAmín Altamirano; Nolwenn Le Pierrès; Benoit Stutz; Alberto Coronas. 2020. "Performance characterization methods for absorption chillers applied to an NH3-LiNO3 single-stage prototype." Applied Thermal Engineering 185, no. : 116435.
At present, novel, small-to-large capacity absorption chillers with unique technical features have emerged on the global market, and laboratory and pre-industrial prototypes have also been developed. These chillers have been designed for the efficient use of low-grade heat sources; some are air-cooled, small capacity systems; compact water/LiBr chillers; or solar-gas-fired single/double-effect chillers. Also, some advanced commercial absorption chillers have an extensive temperature glide in the driving heat stream (>30 K) which extracts approximately twice as much heat (~200%) as the single-effect chiller. This large temperature glide means that the chillers are well suited to solar thermal collector installations and district heating networks, and the extra driving heat increases cold production. Moreover, recent advances in R718 turbo compressor technologies have helped to solve the problems water/LiBr absorption chillers have in adapting to extreme operating conditions (e.g., high ambient temperature, >35 °C) by using a compressor-boosted absorption chiller configuration. This review paper presents and discusses the developments and progress in these absorption chiller technologies. In summary, the new absorption chillers may be useful for developing efficient, cost-effective, and robust solar cooling solutions that are needed to mitigate the unsustainable impact of the rising global demand for space cooling.
Dereje Sendeku Ayou; Alberto Coronas. New Developments and Progress in Absorption Chillers for Solar Cooling Applications. Applied Sciences 2020, 10, 4073 .
AMA StyleDereje Sendeku Ayou, Alberto Coronas. New Developments and Progress in Absorption Chillers for Solar Cooling Applications. Applied Sciences. 2020; 10 (12):4073.
Chicago/Turabian StyleDereje Sendeku Ayou; Alberto Coronas. 2020. "New Developments and Progress in Absorption Chillers for Solar Cooling Applications." Applied Sciences 10, no. 12: 4073.
A solar-gas fired absorption cooling system has been installed and tested in a real environment at the University of Indonesia, Depok, Indonesia. The cooling system provides chilled water to the building of the Mechanical Research Center of the university. This system has a unique single/double-effect water/Lithium Bromide absorption chiller with a nominal cooling capacity of 239 kW. In addition, the system consists of evacuated tube solar collectors (~181 m2 total aperture area) and fan coil units installed in the building. The absorption chiller is driven by (i) hot water (75 – 90 °C) produced by the solar collectors which supply heat to the single-effect generator and (ii) by a direct gas-fired burner at the double-effect high-temperature generator when it is needed. The driving heat supply from the gas-burner is 113.2 kW and 93.3 kW (at 90 °C) from the solar collector field. This study focuses on the control strategy of the solar-gas fired absorption chiller system based on operational data obtained from the field test carried out in an Asian tropical climate, particularly Indonesia. The proposed and implemented control strategy consists of the control of both external and internal operation variables. The external control strategy includes the control of three water flow loops (hot water, cooling water, and chilled water) that are controlled according to the cooling load of the building and weather conditions (i.e., solar irradiation and ambient temperature). The internal operation variable (total solution flow rate) and gas flow rate are adjusted according to the required cooling capacity. The field tests of thermal and electrical COP are around 0.9–1.1 and 4.5–5.5, respectively. The field test results demonstrate the feasibility of the implemented control strategy for the optimum and safe operation of the system in an Indonesian climate, with the possibility of adapting to other similar Asian tropical climates.
M.I. Alhamid; Alberto Coronas; Arnas Lubis; Dereje S. Ayou; Nasruddin; Kiyoshi Saito; Hajime Yabase. Operation strategy of a solar-gas fired single/double effect absorption chiller for space cooling in Indonesia. Applied Thermal Engineering 2020, 178, 115524 .
AMA StyleM.I. Alhamid, Alberto Coronas, Arnas Lubis, Dereje S. Ayou, Nasruddin, Kiyoshi Saito, Hajime Yabase. Operation strategy of a solar-gas fired single/double effect absorption chiller for space cooling in Indonesia. Applied Thermal Engineering. 2020; 178 ():115524.
Chicago/Turabian StyleM.I. Alhamid; Alberto Coronas; Arnas Lubis; Dereje S. Ayou; Nasruddin; Kiyoshi Saito; Hajime Yabase. 2020. "Operation strategy of a solar-gas fired single/double effect absorption chiller for space cooling in Indonesia." Applied Thermal Engineering 178, no. : 115524.
The use of industrial excess heat in district heating networks is very attractive. The main issue is the transport of the heat from the point of generation to the local distribution network, in a way similar to the structure of electricity transport and distribution networks. Absorption systems have been proposed to transport and distribute waste heat using two absorption stations. In one of them (step-up station), industrial heat at a low temperature is pumped to a higher temperature to facilitate its transport and at the same time increase the temperature difference between the supply and return streams, in this way reducing the hot water mass flow rate circulating through the heat transport network. Heat is then used in a second absorption system (step-down station) to provide heat to a low temperature local district network. In this paper, several absorption system configurations are analyzed for both stations. A detailed thermodynamic analysis of each configuration is performed using selected energy performance indicators to calculate its global performance. The implementation of these kind of systems could enable the use of waste heat to produce heating and cooling for smart communities located a few dozens of kilometers away from industrial sites.
Antonio Atienza-Márquez; Joan Carles Bruno; Alberto Coronas. Recovery and Transport of Industrial Waste Heat for Their Use in Urban District Heating and Cooling Networks Using Absorption Systems. Applied Sciences 2019, 10, 291 .
AMA StyleAntonio Atienza-Márquez, Joan Carles Bruno, Alberto Coronas. Recovery and Transport of Industrial Waste Heat for Their Use in Urban District Heating and Cooling Networks Using Absorption Systems. Applied Sciences. 2019; 10 (1):291.
Chicago/Turabian StyleAntonio Atienza-Márquez; Joan Carles Bruno; Alberto Coronas. 2019. "Recovery and Transport of Industrial Waste Heat for Their Use in Urban District Heating and Cooling Networks Using Absorption Systems." Applied Sciences 10, no. 1: 291.
Mutual diffusion coefficients of a binary mixture of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate have been investigated by means of experimental and predictive approaches. Optical digital interferometry has been employed to determine the mutual diffusion coefficients over the full ionic liquid mass fraction range and at four temperatures between 298.15 and 313.15 K. Moreover, the prediction ability of four different models has been tested. The influence of using different excess Gibbs energy (gE) models to calculate the relevant thermodynamics properties was also addressed. The mutual diffusion coefficient has a strong dependence on concentration and varies from 2 × 10−10 to 1.27 × 10−9 m2 s−1. The concentration and temperature dependencies of the present experimental diffusion coefficients were correlated using empirical and predictive equations. The use of binary interaction parameter regressed from diffusion data instead of vapor-liquid equilibria improves considerably the prediction ability of the employed predictive models. Among the studied predictive models, the modified group contribution model provides the best results with an absolute relative deviation of 2.1%. Throughout the paper, thermodynamic and kinetic behavior of the mixture are analyzed for establishing an appropriate criterion for the screening of ionic liquids as working fluids for absorption refrigeration systems.
R. Rives; A. Mialdun; V. Yasnou; V. Shevtsova; A. Coronas. Experimental determination and predictive modelling of the mutual diffusion coefficients of water and ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate. Journal of Molecular Liquids 2019, 296, 111931 .
AMA StyleR. Rives, A. Mialdun, V. Yasnou, V. Shevtsova, A. Coronas. Experimental determination and predictive modelling of the mutual diffusion coefficients of water and ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate. Journal of Molecular Liquids. 2019; 296 ():111931.
Chicago/Turabian StyleR. Rives; A. Mialdun; V. Yasnou; V. Shevtsova; A. Coronas. 2019. "Experimental determination and predictive modelling of the mutual diffusion coefficients of water and ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate." Journal of Molecular Liquids 296, no. : 111931.
Compression/resorption refrigeration systems are similar to conventional vapor compression systems but using zeotropic mixtures with large boiling temperature difference, similar to the refrigerant/absorbent mixtures used in absorption technology. A resorber and a desorber replace the conventional condenser and evaporator, respectively. As the saturation temperature in both desorber and resorber change with the composition, there is a gliding temperature that can reduce the irreversibility of the heat transfer with external sensible heat and sink sources. Another advantage of these systems is that they operate at lower pressures and pressure ratios than the conventional ones. CO2/acetone mixture was proposed for automotive air-conditioning with compression/resorption systems. In this paper, different methods are evaluated for modelling the thermodynamic properties, using experimental data. The selected thermodynamic model will be used to study the performance of the compression/resorption refrigeration cycle.
R J B Moreira-Da-Silva; D Salavera; A Coronas. Modelling of CO2/acetone fluid mixture thermodynamic properties for compression/resorption refrigeration systems. IOP Conference Series: Materials Science and Engineering 2019, 595, 012030 .
AMA StyleR J B Moreira-Da-Silva, D Salavera, A Coronas. Modelling of CO2/acetone fluid mixture thermodynamic properties for compression/resorption refrigeration systems. IOP Conference Series: Materials Science and Engineering. 2019; 595 (1):012030.
Chicago/Turabian StyleR J B Moreira-Da-Silva; D Salavera; A Coronas. 2019. "Modelling of CO2/acetone fluid mixture thermodynamic properties for compression/resorption refrigeration systems." IOP Conference Series: Materials Science and Engineering 595, no. 1: 012030.
Liquefied Natural Gas (LNG) is becoming vital in relation to energy transition and fighting climate change. Because of its cryogenic temperature (111 K), LNG is an exergy “mine” that can be exploited in the regasification process for multiple industrial applications. But this exergy is usually wasted. This research presents a Combined Cold and Power (CCP) system with exergy recovery from LNG-regasification. This exergy is exploited for the combined production of electricity and low-temperature refrigeration distributed through a CO2 District Cooling Network. These systems entail many benefits, but also pending challenges. The CCP system is modelled using real operation data, and its performance is analyzed and benchmarked against that of a cryogenic power plant, both at design and off-design operating conditions. The proposed CCP system reports an equivalent electricity saving of 139 kWh/t-LNG with an exergetic efficiency of 40%, turning into useful energy up to 64% of the maximum cold recoverable in the regasification process. The performance enhances as the heat source temperature rises. Higher LNG flow rates contribute to increase the electricity and refrigeration production, but irreversibilities also increase. Finally, findings show that a low LNG regasification pressure is preferable in spite of the negative effect on the power generation.
Antonio Atienza-Márquez; Joan Carles Bruno; Atsushi Akisawa; Alberto Coronas. Performance analysis of a combined cold and power (CCP) system with exergy recovery from LNG-regasification. Energy 2019, 183, 448 -461.
AMA StyleAntonio Atienza-Márquez, Joan Carles Bruno, Atsushi Akisawa, Alberto Coronas. Performance analysis of a combined cold and power (CCP) system with exergy recovery from LNG-regasification. Energy. 2019; 183 ():448-461.
Chicago/Turabian StyleAntonio Atienza-Márquez; Joan Carles Bruno; Atsushi Akisawa; Alberto Coronas. 2019. "Performance analysis of a combined cold and power (CCP) system with exergy recovery from LNG-regasification." Energy 183, no. : 448-461.
Liquefied Natural Gas (LNG) is a valuable exergetic source due to its low-temperature (−162 °C). However, LNG is regasified using seawater as heat source and without exergy recovery in most of LNG terminals worldwide. In this paper we model a polygeneration plant that recovers the low-temperature and pressure exergy from LNG-regasification to generate simultaneously power and refrigeration in a District Cooling network at three different temperature levels. The plant is divided into different subsystems arranged in cascade. The objective of this research is the selection of the most suitable working fluids and heat transfer fluids for operating in each subsystem. The performance of the system is analyzed from the thermodynamic and environmental point of view. Although neither of the candidate fluids satisfies all the desirable features, the selected fluids are: methane, carbon dioxide and propane. The plant achieves an equivalent electricity production of 125 kWh for metric ton of LNG regasified with an exergetic efficiency of 40.6%. Besides, the seawater utilized in the plant is 60% lower than the required by the common LNG regasification process and an annual emission of 75 thousand tons of CO2 is avoided.
Antonio Atienza-Márquez; Joan Carles Bruno; Atsushi Akisawa; Masayuki Nakayama; Alberto Coronas. Fluids selection and performance analysis of a polygeneration plant with exergy recovery from LNG-regasification. Energy 2019, 176, 1020 -1036.
AMA StyleAntonio Atienza-Márquez, Joan Carles Bruno, Atsushi Akisawa, Masayuki Nakayama, Alberto Coronas. Fluids selection and performance analysis of a polygeneration plant with exergy recovery from LNG-regasification. Energy. 2019; 176 ():1020-1036.
Chicago/Turabian StyleAntonio Atienza-Márquez; Joan Carles Bruno; Atsushi Akisawa; Masayuki Nakayama; Alberto Coronas. 2019. "Fluids selection and performance analysis of a polygeneration plant with exergy recovery from LNG-regasification." Energy 176, no. : 1020-1036.
Ammonia/water absorption-resorption refrigeration systems are an interesting technological alternative to conventional absorption systems thanks to their additional degree of freedom, which makes operation more flexible and can significantly reduce the typically high working pressure, so cheaper assembly materials can be used. This paper aims to review the theoretical and experimental works carried out so far on these systems, paying special attention to the experimental plants currently operating and recent progress in improving system control. This paper reports how to determine the operational pressure range when the temperatures of the main components of the ammonia/water single-stage cycle are fixed and how the pressure range changes when these working temperatures are varied. As a result of the theoretical study of the base case selected, the cycle performance was evaluated without rectification after the generator in order to reduce the size and cost of the system without reducing the performance. Finally, it should be pointed out that the effectiveness of the resorption solution heat exchanger plays an important role in the performance and operating conditions of the cycle because the cycle cannot work below certain values of effectiveness.
M. Berdasco; M. Vallès; A. Coronas. Thermodynamic analysis of an ammonia/water absorption–resorption refrigeration system. International Journal of Refrigeration 2019, 103, 51 -60.
AMA StyleM. Berdasco, M. Vallès, A. Coronas. Thermodynamic analysis of an ammonia/water absorption–resorption refrigeration system. International Journal of Refrigeration. 2019; 103 ():51-60.
Chicago/Turabian StyleM. Berdasco; M. Vallès; A. Coronas. 2019. "Thermodynamic analysis of an ammonia/water absorption–resorption refrigeration system." International Journal of Refrigeration 103, no. : 51-60.
The purpose of this paper is to determine the amount of water in ionic liquid aqueous solutions that does not form hydrogen bonds (that is to say, free water). Here, the amount of free water was determined in mixtures of water and four ionic liquids based on the imidazolium cation: 1-Butyl-3methylimidazolium acetate, 1-Butyl-3methylimidazolium bromide, 1-Butyl-3methylimidazolium chloride, and 1–3, dimethyl-imidazolium chloride. Their ionic liquid mass fraction was between 0 and 80%. The amount of free water in the mixtures was determined from the concentration profiles obtained by analysing the near infrared spectra of the mixtures between 800 and 1070 nm using multivariate curve resolution-alternating least squares. The absorption band characteristic of the OH- group in the water is present in the spectral region considered. The analysis was done at three temperatures: 298.15, 313.15 and 333.15 K. The major conclusions obtained from a comparative analysis of the results are these: a) the length of the alkyl chain significantly affects the hydrophobicity of the cations when the molality of the ionic liquid in the solutions is higher than 1.435 mol/kg. b) for the solutions with the same cation, the amount of free water in the chloride solutions is lower than in the acetate and bromide solutions when the temperature is lower than 333.15 K. At this temperature, the capacity of acetate and bromide solutions to interact with water is the same. Between 298.15 and 333.15 K, the ionic liquid concentration at which there is no free water in the solutions ranges between 62.70 and 59.59% for the 1–3, dimethylimidazolium chloride, 66.72 and 87.75% for the 1-Butyl-3methylimidazolium chloride, 69.76 and 78.36% for the -1-Butyl-3methylimidazolium bromide and between 69.77 and 78.26% for the 1-Butyl-3methylimidazolium acetate. So, the ionic liquid with the greatest capacity to retain water is the 1–3, dimethylimidazolium chloride.
M. Isabel Barba; M. Soledad Larrechi; Alberto Coronas. Quantitative analysis of free water in ionic liquid-water mixtures. Talanta 2019, 199, 407 -414.
AMA StyleM. Isabel Barba, M. Soledad Larrechi, Alberto Coronas. Quantitative analysis of free water in ionic liquid-water mixtures. Talanta. 2019; 199 ():407-414.
Chicago/Turabian StyleM. Isabel Barba; M. Soledad Larrechi; Alberto Coronas. 2019. "Quantitative analysis of free water in ionic liquid-water mixtures." Talanta 199, no. : 407-414.
We rank the expected solubilities of ammonia in three hydroxyl ionic liquids – [HOEMIm][BF4], [HOEMIm][NTf2] and [Ch][NTf2] – in the temperature range 20–105 °C by analyzing the cations and anions available for interaction with ammonia. As this availability depends on ion-pair formation in ionic liquids, in this paper it is evaluated using the concentration and spectral profiles recovered in the analysis of their near infrared spectra by the multivariate resolution curve - alternating least squares method. The results indicate that the main effect of temperature on ion pairs is to decrease the number of structural configurations with cooperative hydrogen bonds between cation and cation, although in a lesser extent the number of cation-anion interactions increases. Regardless of the type of ionic liquid cation, the cation-anion interactions are higher in the tetrafluorborate ionic liquid than in the imide ionic liquid, hydroxyl imidazolium or choline. Assuming that the solubility of ammonia is limited by the concentration profile values representative of the cation-cation interactions, we deduce that at temperatures higher than 80 °C, ammonia solubility increases in the following order [HOEMIm][BF4] < [HOEMIm][NTf2] < [Ch][NTf2]. At lower temperatures, this order varies with the ammonia concentration in the NH3/ILs mixtures considered. We deduce that if the ammonia concentration is relatively low, the ammonia solubility will be governed by the evolution of cation-anion interaction in the ionic liquids and the solubility order is the same as at higher temperatures. However, when the ammonia concentration is higher, the ammonia solubility in the [Ch][NTf2] ionic liquid is lower than in the hydroxyl-ionic liquids. This conclusion is supported by the experimental vapor-liquid equilibria (VLE) data of ammonia-/ILs mixtures with ammonia mass fractions between 0.2 and 0.8.
M. Soledad Larrechi; Andry Cera-Manjarres; Alberto Coronas. Ranking the solubility of ammonia in ionic liquids using near infrared spectroscopy and multivariate curve resolution. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2019, 215, 88 -96.
AMA StyleM. Soledad Larrechi, Andry Cera-Manjarres, Alberto Coronas. Ranking the solubility of ammonia in ionic liquids using near infrared spectroscopy and multivariate curve resolution. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2019; 215 ():88-96.
Chicago/Turabian StyleM. Soledad Larrechi; Andry Cera-Manjarres; Alberto Coronas. 2019. "Ranking the solubility of ammonia in ionic liquids using near infrared spectroscopy and multivariate curve resolution." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 215, no. : 88-96.
This paper studies a hybrid system for cold production consisting of a compression cycle combined with a thermochemical process by sharing the same condenser, evaporator and refrigerant fluid. The aim of this hybridization is to solve mismatch issues between the demand of cold and the source of energy (availability and/or price) with a system as compact as possible. One important side benefit is that the interaction between the compressor and the thermochemical reactor reduces the activation temperature for ammonia desorption in the thermochemical reactor. To study this interaction a quasi-steady simulation model for both storage and de-storage phases has been developed and experimentally validated by means of a small scale (approx. 300 Wh of cold storage) experimental bench with ammonia as refrigerant and barium chloride (BaCl2) as reactant salt. Experiments proved a 35 K reduction in the activation temperature of the desorption reaction with respect to desorption without compressor. Model validation by adjusting permeability and thermal conductivity of the reactive composite showed an acceptable agreement between predicted and experimental reaction advancement-time curves. The validated model was used for simulation of the system in a preliminary case study, representative in power (40 kW) and temperature (−25 °C) of an industrial cold demand. It is shown that during ammonia de-storage, the hybrid achieves a higher COP than a conventional mechanical vapor compression system. It increases exponentially with the relative share of thermochemical storage in the cold production.
Jaume Fitó; Alberto Coronas; Sylvain Mauran; Nathalie Mazet; Maxime Perier-Muzet; Driss Stitou. Hybrid system combining mechanical compression and thermochemical storage of ammonia vapor for cold production. Energy Conversion and Management 2018, 180, 709 -723.
AMA StyleJaume Fitó, Alberto Coronas, Sylvain Mauran, Nathalie Mazet, Maxime Perier-Muzet, Driss Stitou. Hybrid system combining mechanical compression and thermochemical storage of ammonia vapor for cold production. Energy Conversion and Management. 2018; 180 ():709-723.
Chicago/Turabian StyleJaume Fitó; Alberto Coronas; Sylvain Mauran; Nathalie Mazet; Maxime Perier-Muzet; Driss Stitou. 2018. "Hybrid system combining mechanical compression and thermochemical storage of ammonia vapor for cold production." Energy Conversion and Management 180, no. : 709-723.
Andry Cera-Manjarres; Daniel Salavera; Alberto Coronas. Vapour pressure measurements of ammonia/ionic liquids mixtures as suitable alternative working fluids for absorption refrigeration technology. Fluid Phase Equilibria 2018, 476, 48 -60.
AMA StyleAndry Cera-Manjarres, Daniel Salavera, Alberto Coronas. Vapour pressure measurements of ammonia/ionic liquids mixtures as suitable alternative working fluids for absorption refrigeration technology. Fluid Phase Equilibria. 2018; 476 ():48-60.
Chicago/Turabian StyleAndry Cera-Manjarres; Daniel Salavera; Alberto Coronas. 2018. "Vapour pressure measurements of ammonia/ionic liquids mixtures as suitable alternative working fluids for absorption refrigeration technology." Fluid Phase Equilibria 476, no. : 48-60.
This paper proposes a novel hybrid refrigeration system with energy storage, driven by low-grade solar heat and consisting of a single-stage absorption cycle coupled with a thermochemical process by sharing the same condenser, evaporator and refrigerant fluid. A first screening of ammonia-based working pairs for evaporation temperatures of −10 °C, condensation temperatures of 30 °C and heat source temperatures of 80 °C reveals LiNO3 as suitable sorbent salt for the absorption subsystem, and BaCl2, PbBr2, SrCl2, LiCl, NH4Br and SnCl2 as candidate reactive salts in the thermochemical subsystem. The subsequent parametric study indicates that the absorption subsystem with NH3/LiNO3 reaches close-to-maximum COP at the indicated conditions, and the thermochemical subsystem delivers its highest COP with the NH3/BaCl2 pair. Then, the power-storage and performance-storage relationships of the thermochemical subsystem are analyzed for the NH3/BaCl2 pair with respect to variations in operating conditions and several implementation parameters of the reactive composite. Finally, the performance of the hybrid system with the (NH3/LiNO3 + NH3/BaCl2) pair combination is compared to its subsystems against a variable demand profile calculated from climatic data of July in Barcelona, Spain. A novel indicator is defined to assess demand coverage: the Coefficient of Satisfaction of Demand (CSD). Depending on solar collector field area and amount of refrigerant storable by the thermochemical subsystem, the hybrid system reaches up to 24% higher CSD than the reference system (a solar single-stage absorption refrigerator with no storage), and at least 14% higher COP than the thermochemical process.
Jaume Fitó; Alberto Coronas; Sylvain Mauran; Nathalie Mazet; Driss Stitou. Definition and performance simulations of a novel solar-driven hybrid absorption-thermochemical refrigeration system. Energy Conversion and Management 2018, 175, 298 -312.
AMA StyleJaume Fitó, Alberto Coronas, Sylvain Mauran, Nathalie Mazet, Driss Stitou. Definition and performance simulations of a novel solar-driven hybrid absorption-thermochemical refrigeration system. Energy Conversion and Management. 2018; 175 ():298-312.
Chicago/Turabian StyleJaume Fitó; Alberto Coronas; Sylvain Mauran; Nathalie Mazet; Driss Stitou. 2018. "Definition and performance simulations of a novel solar-driven hybrid absorption-thermochemical refrigeration system." Energy Conversion and Management 175, no. : 298-312.
It has been estimated that the world’s consumption of liquefied natural gas (LNG) will increase significantly over the next 20 years, thus making exergy recovery from the regasification process a fundamental issue. When LNG is regasified in order to distribute the fuel through a pipeline network, a large amount of exergy is released. Three combined cycle schemes for energy generation have been analysed in this paper: the first one is a direct expansion cycle, combined with a Rankine cycle, the second one presents a double expansion with reheating and a recovery heat exchanger, and the last one shows two parallel Rankine cycles working under different turbine pressures. The performance of the three cycles has been compared, and the effects of using working fluids with different characteristics have been analysed in detail. Twelve working fluids were selected, according to their thermodynamic, ambient and safety proprieties. The working pressure and temperature that maximise the specific work have been found for each cycle and fluid.
Marco Badami; Joan Carles Bruno; Alberto Coronas; Gabriele Fambri. Analysis of different combined cycles and working fluids for LNG exergy recovery during regasification. Energy 2018, 159, 373 -384.
AMA StyleMarco Badami, Joan Carles Bruno, Alberto Coronas, Gabriele Fambri. Analysis of different combined cycles and working fluids for LNG exergy recovery during regasification. Energy. 2018; 159 ():373-384.
Chicago/Turabian StyleMarco Badami; Joan Carles Bruno; Alberto Coronas; Gabriele Fambri. 2018. "Analysis of different combined cycles and working fluids for LNG exergy recovery during regasification." Energy 159, no. : 373-384.
The water activities of sodium molybdate in aqueous solutions at T = (303.15, 313.15, 323.15 and 333.15) K were determined, using vapor pressure osmometry. The range of salt concentration was from 0.06 to 2.2 mol kg−1. The results show that sodium molybdate has a significant effect on the water activity. Values of the vapor pressure, osmotic and activity coefficient of the solutions were determined from the activity data. Finally, the studied system was modeled with the Pitzer model which allowed correlating the properties of these aqueous solutions obtaining a good agreement between the experimental data and the correlated values.
Yecid P. Jimenez; Alberto Coronas; Felipe Hernández-Luis. Water activities of sodium molybdate solutions at different temperatures. Fluid Phase Equilibria 2018, 476, 131 -138.
AMA StyleYecid P. Jimenez, Alberto Coronas, Felipe Hernández-Luis. Water activities of sodium molybdate solutions at different temperatures. Fluid Phase Equilibria. 2018; 476 ():131-138.
Chicago/Turabian StyleYecid P. Jimenez; Alberto Coronas; Felipe Hernández-Luis. 2018. "Water activities of sodium molybdate solutions at different temperatures." Fluid Phase Equilibria 476, no. : 131-138.
Miguel Berdasco; Alberto Coronas; M. Vallès. Study of the adiabatic absorption process in polymeric hollow fiber membranes for ammonia/water absorption refrigeration systems. Applied Thermal Engineering 2018, 137, 594 -607.
AMA StyleMiguel Berdasco, Alberto Coronas, M. Vallès. Study of the adiabatic absorption process in polymeric hollow fiber membranes for ammonia/water absorption refrigeration systems. Applied Thermal Engineering. 2018; 137 ():594-607.
Chicago/Turabian StyleMiguel Berdasco; Alberto Coronas; M. Vallès. 2018. "Study of the adiabatic absorption process in polymeric hollow fiber membranes for ammonia/water absorption refrigeration systems." Applied Thermal Engineering 137, no. : 594-607.