assess the possible degradation quality sterling silver necklaces

To assess the possible degradation of sorbents after multiple hydration/dehydration cycles, the hydrated zeolite beads are then dried in an oven with controlled temperature, and the hydration test repeated. doi: 10.1016/j.pecs.2015.10.003, Zhao, R., Liu, J., and Gu, J. To this, we consider a portable electric power generator operating in cold climates, and envision the improvement of the efficiency of its Diesel engine during the cold-start using waste heat recovered from the exhaust gases and stored using the proposed TES system. Energy 258:114086. doi: 10.1016/j.apenergy.2019.114086, Narayanan, S., Kim, H., Umans, A., Yang, S., Li, X., Schiffres, S. N., et al. doi: 10.1016/j.pecs.2013.05.004, Zettl, B., Englmair, G., and Steinmaurer, G. (2014). Thermal energy storage: recent developments and practical aspects. Clim. 6:17. doi: 10.3389/fenrg.2018.00017, Heinke, L., Gu, Z., and Wll, C. (2014). (2016). Compendium of Chemical Terminology, Vol. Note that, at ambient pressure, the freezing points of pure ethanol and 30:70%wt. Int. Health, safety and environment, in Computer Aided Chemical Engineering, Vol. (2016b). Energy 203, 219239. Sci. (2010). However, both sensible and latent heat storage are prone to progressive degradation of the stored energy, which is due to thermal losses toward the surrounding environment and makes them unsuitable for long-term heat storage (Farid et al., 2004). 7:148. doi: 10.3389/fenrg.2019.00148. Energy Combust. J. Figure 3. Int. 30, 631638. (2017). (2016). TES has recently attracted particular attention in the renewable energy field, to match periodical or intermittent availability of renewable sources (e.g., solar) with continuous energy demand (Daz-Gonzlez et al., 2012; Engel et al., 2017; Bocca et al., 2018). In this work, we aim at characterizing the feasibility of a sorption TES cycle with liquid sorbates at ambient conditions, thus not requiring auxiliary systems for vapor generation. On the one side, the use of Winter or Arctic Diesels can prevent the risk of fuel gelling and filter clogging in cold weather conditions (Mitchell and Chandler, 1998); on the other side, cylinders are typically pre-heated by means of glowplugs (Lindl and Schmitz, 1999). Internal combustion engine cold-start efficiency: a review of the problem, causes and potential solutions. Thermal energy storage also finds application in the transport sector, for which a reduction of greenhouse gas emissions is foreseen by the recent international agreements on climate change mitigation (Schleussner et al., 2016; Xue et al., 2016). Low Temperature Thermal Energy Storage (TES) System for Improving Automotive HVAC Effectiveness. doi: 10.4271/982576, Morciano, M., Fasano, M., Bergamasco, L., Albiero, A., Lo Curzio, M., Asinari, P., et al. Ther. (2014). (2015). On the other hand, the water-zeolite pair presents the highest heat storage density; therefore, the mixture represents a good compromise between energy storage density and dehydration temperature. Loaded liquid fraction ( in Equation 1) obtained for twelve repetitions of the experimental characterization test at ambient pressure (p = 1 bar) and temperature (T = 20C) on pristine zeolite samples for the different tested fluids (water, ethanol and 30:70%wt. Daz-Gonzlez, F., Sumper, A., Gomis-Bellmunt, O., and Villaffila-Robles, R. (2012). Oxford: Blackwell Science. In fact, the amount of loaded sorbate depends on the affinity between its fluid molecules and the zeolite surface, and on the size of the fluid molecules with respect to that of the pores and cages in the zeolite framework. At fully hydrated conditions, the fraction between the mass of loaded liquid (mliq,fh) and the one of dry sorbent (mzeo) is here defined as. Energy Storage 17, 118128. (2018). In fact, the ideal performance of water vapor adsorption on 13XBFK zeolite are (Mette et al., 2014b; Pinheiro et al., 2018): heat of adsorption approximately equal to hads = 3,500 kJ/kg (released energy per kilogram of adsorbed water, that is 63 kJ/mol); maximum water vapor load on zeolite = 0.34. The suboptimal performance observed in our tests are due to the implemented hydration process, which employs part of the released heat of adsorption to drive the phase change of the sorbate from liquid to vapor. This example shows that liquid hydration may be adopted as a simple and low-cost alternative to more efficientyet more expensivetechniques for long-term energy storage. A review on long-term sorption solar energy storage. All tests are carried out for the three considered fluids, that is, water, ethanol and their mixture. Assessment of adsorbate density models for numerical simulations of zeolite-based heat storage applications. Ther. Cold Start Equipment for Diesel Direct Injection Engines. At 100C, for example, the amount of water released from the zeolite is about 45% respect to fully hydrated conditions, while this quantity is close to 60% for the ethanol and mixture sorbates. The Use of Flow Improved Diesel Fuel at Extremely Low Temperatures. Eng. Typically, materials such as rock, concrete, steel, thermal oil and water are used for sensible heat storage (Hoogendoorn and Bart, 1992). Process intensification principles applied to thermal energy storage systemsa brief review. In these experiments, hydrated zeolite samples have been regenerated at 250C for 20 min. Ouden, C. (1981). Besides chemical reactions (Donkers et al., 2016), thermo-chemical storage can be based also on sorption processes. Flick, E. W. (1998). Solar energy: a common-sense vision. Severe cold-start conditions are considered, namely an ambient temperature equal to 20C, which is anyway above the freezing point of both ethanol and mixture. Phys. Frazzica, A., and Freni, A. Zeolite 13X has average pore size around 9 , which allows intrusion of both molecules; however, also because of their smaller size, water molecules can achieve larger adsorption on the zeolite structure. Latent heat storage shows typically larger energy density than sensible one (about 30100 kWh/m3, Lizana et al., 2017) and, thus, has been widely explored in solar (Andreozzi et al., 2018; Buonomo et al., 2018) and automotive applications (Jaguemont et al., 2018). Renew. doi: 10.1039/C8TA00827B, Roberts, A., Brooks, R., and Shipway, P. (2014). This calculation also proofs that the higher water load observed in our experiments ( = 0.50) could be explained by a residual quantity of liquid water on the surface of the zeolite bead after the hydration process, which is not involved in the adsorption process. Nat. 13, 23852396. 1:3. doi: 10.3389/fenrg.2013.00003. 138, 849860. The sorbent hydration by liquid sorbates shows lower heat storage performance than vapor hydration; yet, it provides similar heat storage density to that obtainable by latent heat storage (4050 kWh/m3) at comparable costs, robustness and simplicity of the system, while gaining the long-term storage capabilities of sorption-based technologies. Given their auxiliary scope, these generators are not typically subject to frequent start-stop cycling, which makes them lend to a TES system able to store thermal energy for long periods with negligible losses. Energy Convers. PA, EC, and MF contributed conception and design of the study. Sustainable freshwater production using passive membrane distillation and waste heat recovery from portable generator sets. Membranes 9:76. doi: 10.3390/membranes9070076, Lehmann, C., Beckert, S., Glser, R., Kolditz, O., and Nagel, T. (2017). 116, 364371. Eng. The heat storage density has been also evaluated for zeolite samples regenerated up to 10 times, to assess the cyclability of the hydration/dehydration process. Adsorption heat storage: state-of-the-art and future perspectives. Front. Technical report, SAE Technical Paper, BERU AG. 20, 913923. doi: 10.4271/2017-01-0150, Stritih, U., and Bomba, A. Thermal Energy Storage (TES) systems allow to store excess thermal energy and to use it at a later time (Zhang et al., 2016). In this work, we characterize the heat storage potential of various liquid sorbates (distilled water, ethanol and a mixture thereof) on a commercial 13X zeolite sorbent at ambient pressure. As reported in Table 1, this would lead to a potential increase of approximately 40C in the fuel temperature, which would sharply decrease its kinematic viscosity from 16.82 mm2/s (20C) to either 3.46 mm2/s (23.5C, zeolite hydrated by mixture) or 3.94 mm2/s (18.1C, zeolite hydrated by ethanol) (Dauk et al., 2008). Sorption heat storage for long-term low-temperature applications: a review on the advancements at material and prototype scale. Eng. Sci. Coffee-based colloids for direct solar absorption. Eng. doi: 10.1016/S0035-3159(99)80020-8, Vasta, S., Brancato, V., La Rosa, D., Palomba, V., Restuccia, G., Sapienza, A., et al. doi: 10.1016/j.energy.2017.12.037, Andreozzi, A., Buonomo, B., Ercole, D., and Manca, O. Energy 144, 341378. doi: 10.1016/B978-0-444-62700-1.00016-4, Donkers, P., Pel, L., and Adan, O. Energy Rev. In this section, we provide an illustrative example application of the proposed thermal energy storage system in practice. Energy Storage 5, 2532. A. Influence of different adsorbates on the efficiency of thermochemical energy storage. In the followings, a TES system based on the tested 13X zeolite hydrated by ethanol (E = 49 kWh/m3; = 0.40 after multiple regenerations at 250C) or the 30:70%wt. doi: 10.1039/c1cp21731c, Fleming, E., Wen, S., Shi, L., and da Silva, A. K. (2013). doi: 10.1016/j.est.2017.06.001, Farid, M. M., Khudhair, A. M., Razack, S. A. K., and Al-Hallaj, S. (2004). Clearly, the liquid hydration is inefficient with respect to the typical vapor one; however, it does not require vacuum reactors and cumbersome auxiliary systems therefore allowing a simpler assembly. Note that the first regeneration cycle reports the heat storage density and hydration capacity of pristine zeolite samples, as provided by the manufacturer. (2019). Although the thermal performance of zeolite-liquid hydration is lower than those typically reported for vapor hydration, using liquids may still represent an option when simple design and long-term storage are required. The authors acknowledge funding from DENSO Thermal Systems (Technical European Centre, Italy). Eng. Technical report, SAE Technical Paper, The University of Leeds. The energy provided to the engine fluids is equal to Qd. Chem. 7:12762. doi: 10.1038/ncomms12762, First, E. L., Gounaris, C. E., Wei, J., and Floudas, C. A. Experimental and numerical investigations on the water vapor adsorption isotherms and kinetics of binderless zeolite 13x. Insulated expansion tank (iet) and thermal storage for engine cold start, in 1995 SAE International Congress and Exposition, SAE Technical Paper, 950994. doi: 10.4271/950994. doi: 10.1016/j.apenergy.2016.06.147, Mitchell, K., and Chandler, J. J. doi: 10.1109/SDPC.2017.131, Keywords: thermal energy storage, adsorption, zeolite, water, ethanol, experimental characterization, Citation: Fasano M, Bergamasco L, Lombardo A, Zanini M, Chiavazzo E and Asinari P (2019) Water/Ethanol and 13X Zeolite Pairs for Long-Term Thermal Energy Storage at Ambient Pressure. doi: 10.1016/j.apenergy.2015.10.126. Heat is stored in a narrow temperature range; therefore, PCM must have phase-transition temperature in the range of practical interest, besides being chemically stable, non-toxic and non-corrosive (Farid et al., 2004). (2018). Figure 5. These results confirm that the employed dehydration process (20 min at 250C) is suitable to (almost) fully regenerate the zeolite from ethanol and mixture; whereas, a substantial amount of water remains in the zeolite pores after the regeneration. A thermophysical battery for storage-based climate control. In particular, the negligible heat losses of sorption technologies during the storing period make them ideal for applications where long-term storage is required. IEA-ETSAP and IRENA (2013). Appl. For all the tested sorbates and temperatures, the experimental data on the regeneration grade show a clear trend as a function of time, which can be accurately recoveredat least for the considered duration of experimentsby the following exponential expression. (A) Heat discharge phase: the liquid sorbate (S) is released into the chamber containing the zeolite (Z), thus hydrating it (Z/S). Three laboratory tests are set up to characterize the zeolite properties for heat storage, namely: liquid sorbate hydration, dehydration and heat storage density. Technical report, SAE Technical Paper; Shell Canada Limited; Exxon Chemical Company. In general, thermo-chemical heat storage relies on the sorbent hydration by sorbate vapor to achieve larger heat storage density. (2014). Commun. Sustain. J. Phys. Sci. Qr is obtained via calorimetric measurements, while Vzeo = mzeo/zeo with zeo = 800 kg/m3. doi: 10.1016/S1359-4311(99)00061-7, Vasiliev, L. L., Burak, V. S., Kulakov, A. G., Mishkinis, D. A., and Bohan, P. V. (1999). Note that the considered dehydration temperature is kept far from the autoignition temperature of ethanol, that is 425C (Dimian et al., 2014). Technology Brief. Since the capped flask has negligible heat losses with the surrounding environment (less than 5%), the system can be reasonably approximated as adiabatic. The characteristic regeneration time is the time constant of the exponential-decay term in the above equation, and represents the time at which the regeneration grade is around 63% its maximum value. In general, TES techniques are mainly divided into three types: sensible, latent and thermo-chemical heat storage (Cabeza, 2015; Guo and Goumba, 2018). Chemiewerk Bad Kstritz Gmbh, Germany. (2017). doi: 10.1016/j.rser.2009.05.008. In the third application case, the whole tank of the coolant (11.4 L) could be pre-heated by the zeolite at the engine starting. Prog. ethanol-water mixture. Manage. ethanol-water mixture). Nat. Kauranen, P., Elonen, T., Wikstrm, L., Heikkinen, J., and Laurikko, J. Energy 179, 284301. Since no vacuum systems are needed to handle the liquid sorbents, this solution may be particularly suitable for robust, long-term, low-cost and electricity-free thermal energy storage systems. with Rg,max being the maximum regeneration grade and the characteristic regeneration time per each sorbent-sorbate pair and temperature. (2018). Table 1. Ethanol and water are both polar liquids; yet, the kinetic diameter of water molecules is about 2.96 , while ethanol ones about 4.30 (La Rocca et al., 2019). doi: 10.1016/j.egypro.2017.08.229, Fasano, M., Borri, D., Chiavazzo, E., and Asinari, P. (2016a). For the sake of simplicity, heat losses are estimated parametrically as Qloss = 0.5 E Vzeo (to be conservative). Experimental studies for the cyclability of salt hydrates for thermochemical heat storage. Energy Rev. doi: 10.1016/j.applthermaleng.2014.04.069, Zhang, H., Baeyens, J., Caceres, G., Degreve, J., and Lv, Y. 6, 124137. The energy provided to the TES system is equal to Qc. doi: 10.1021/ef3016574, Risti, A., Fischer, F., Hauer, A., and Logar, N. Z. doi: 10.1016/j.est.2018.02.014. 15, 32203228. Heat Transf. In this field, the design of efficient, reliable and economically-sustainable systems for thermal energy storage represents a major technological challenge to increase the renewable share on the global energy production (Ginley and Parilla, 2013). (B) Overview of the material and instruments used for the experimental characterization of the sorption working pairs: (1) Dewar flask, (2) insulated tap, (3) K-type thermocouple, (4) zeolite containers, (5) precision balance. Technical report, SAE Technical Paper, Valeo Climate Control; CNRS/IMP. doi: 10.1016/j.est.2015.11.005, Engel, G., Asenbeck, S., Kll, R., Kerskes, H., Wagner, W., and van Helden, W. (2017). Appl. Development and characterization of silane-zeolite adsorbent coatings for adsorption heat pump applications. ethanol-water mixture (E = 56 kWh/m3; = 0.47 after multiple regenerations at 250C) is considered. Eng. McNaught, A. D., and McNaught, A. D. (1997). Note that the heat storage density of water vapor on 13XBFK zeolite shown in previous works (Mette et al., 2014a; Lehmann et al., 2017) is 23 times higher with respect to the values measured here. 16, 52075224. The zeolite samples are supplied as spherical beads with diameter in the range 2.53.5 mm (see Figure 1A). doi: 10.1016/j.apenergy.2013.05.058. Commun. Energy Combust. Adsorbent working pairs for solar thermal energy storage in buildings. However, after this initial drop in heat storage performance, E presents only slight decreases in the successive hydration/dehydration cycles, in average: 0.81 kWh/m3 per cycle for the water sorbate; 0.38 kWh/m3 per cycle for the ethanol; 0.59 kWh/m3 per cycle for the mixture. Appl. Appl. During the hydration test, the dry zeolite beads (10 g per test) are placed in a container, which is then completely filled by the considered sorbate. Prog. This different release rate could be attributed to the different affinity of the fluid molecules with the surface of the zeolite pores. Figure 5C reports the fraction of loaded sorbate with respect to the sorbent mass for 10 successive hydration/dehydration cycles. Cold Regions Eng. Technical report, SAE Technical Paper, Mahle Behr Troy Inc.; Oak Ridge National Laboratory; Ford Motor Company. Appl. doi: 10.1016/j.ijheatmasstransfer.2013.12.061, Mir, L., Gasia, J., and Cabeza, L. F. (2016). In the second application case, the whole tank of the lubricant (4.1 L) could be pre-heated by the TES system during the engine starting. (2019). Change 6:827. doi: 10.1038/nclimate3096, Shere, L., Trivedi, S., Roberts, S., Sciacovelli, A., and Ding, Y. Different application cases of a TES system based on 13X zeolite and liquid sorbate (MIX: 30:70%wt. Sensible heat storage finds application in domestic systems, district heating, industrial plants (Alva et al., 2018), solar (Andreozzi et al., 2012) and automotive systems (Ap and Golm, 1995; Aguiar et al., 2013). doi: 10.4271/2013-36-0246, Alberghini, M., Morciano, M., Bergamasco, L., Fasano, M., Lavagna, L., Humbert, G., et al. However, the low heat storage density of sensible heat storagewhich is typically in the range 070 kWh/m3 (Lizana et al., 2017)represents a severe bottleneck in applications with limited free volume available, e.g., in case of automobiles. Advances in Thermal Energy Storage Systems: Methods and Applications. Heat storage device for pre-heating internal combustion engines at start-up. The cap is then positioned on the top of the flask, with a thin paper sheet preventing the zeolite beads from falling into the flask. MF and LB analyzed the data and wrote the manuscript. The experiments are performed according to the following protocol. As a representative application example of long-term storage, we verify the feasibility of a sorption heat storage system with liquid sorbate, which could be used to improve the cold-start of stand-by generators driven by internal combustion engines. Phys. The editor and reviewer's affiliations are the latest provided on their Loop research profiles and may not reflect their situation at the time of review. In the schematics reported in Figure 6, the heat discharge and charge phases of the TES system are depicted. doi: 10.1016/j.applthermaleng.2016.02.015, Fasano, M., Humplik, T., Bevilacqua, A., Tsapatsis, M., Chiavazzo, E., Wang, E. N., et al. The experimental characterization of a commercially-available zeolite for sorption heat storage has been carried out and reported. Twelve repetitions have been performed, using a new sample of zeolite for each test. (2017). 1669. A review on phase change energy storage: materials and applications. The ethanol and related mixture in water have been chosen for their low freezing point (114C and 20C, respectively), which makes them suitable for utilization in severe low temperatures. The sorbent reacts with the liquid sorbate, producing an exothermic reaction that releases heat (hydration process). Jaguemont, J., Omar, N., Van den Bossche, P., and Mierlo, J. Figure 4A shows that the best-fitted Rg,max are linearly dependent on temperature; whereas, no significant differences are observed between the three tested fluids. Development and Optimization of PCM Based Technology for Cooling Applications for Improvement of Fuel Efficiency in Commercial Vehicle. Renew. The different sorption pairs have been experimentally characterized in terms of hydration capacity, dehydration dynamics and heat storage density at ambient pressure. Sci. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). 126, 509516. The excess sorbate is successively removed from the container; whereas, the loaded mass of sorbate is estimated as the difference in weight between the zeolite beads before and after full hydration, using the precision balance shown in Figure 1B (Radwag PS 1000_R2, 0.001 g resolution). 70, 4249. Results in Figures 5A,B show that water hydration provides higher heat storage density (80 kWh/m3) with respect to ethanol (49 kWh/m3) and mixture (56 kWh/m3) ones. Appl. Nanomaterials 8:522. doi: 10.3390/nano8070522, Wang, M., Craig, T., Wolfe, E., LaClair, T. J., Gao, Z., Levin, M., et al. Figures 3A,B allow to appreciate this effect for the two pure fluids (water and ethanol), while Figure 3C shows the intermediate behavior of the mixture. Energy Res. Appl. Solar energy latent thermal storage by phase change materials (PCMS) in a honeycomb system. Renew. In very cold climates indeed, low temperatures may lead to several issues, such as a large concentration of CO and CnHn in the exhausts, reduced engine resource time, high load on starter and accumulator and increased fuel consumption during the cold-start (Diemand, 1992), due to the high viscosity of fuel and lubricant and to the difficult ignition at low temperatures (Piperel et al., 2013).