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101.
《International Journal of Hydrogen Energy》2021,46(59):30267-30287
This work aims to improve the existing monitoring systems MS for two grid-connected PV stations GCPVS of URERMS ADRAR, to eliminate its limitations. This improvement consists of developing an MS which is used for two PV stations with different configurations. This MS contains new LabVIEW-based monitoring software for visualizing real-time measured data and evaluating GCPVS performance. In addition, it illustrates the 2D and 3D real-time relationships of PV system parameters, which allow us to understand the dynamic behavior of PV system components. This developed monitoring software synchronizes also the various data acquisition units DAU of GCPVS, allowing simultaneous data access.To perform a reliable performance analysis and a comparative study of different GCPVS based on accurate measurements, the sensor's calibration is performed with its DAU. The MS autonomy is ensured by integrating developed PV-UPS. A graphical user interface is provided for the evaluation of PV-UPS performance. 相似文献
102.
《International Journal of Hydrogen Energy》2021,46(67):33486-33495
Two-dimensional (2D) B2O monolayer is considered as a potential hydrogen storage material owing to its lower mass density and high surface-to-volume ratio. The binding between H2 molecules and B2O monolayer proceeds through physisorption and the interaction is very weak, it is important to improve it through appropriate materials design. In this work, based on density functional theory (DFT) calculations, we have investigated the hydrogen storage properties of Lithium (Li) functionalized B2O monolayer. The B2O monolayer decorated by Li atoms can effectively improve the hydrogen storage capacity. It is found that each Li atom on B2O monolayer can adsorb up to four H2 molecules with a desirable average adsorption energy (Eave) of 0.18 eV/H2. In the case of fully loaded, forming B32O16Li9H72 compound, the hydrogen storage density is up to 9.8 wt%. Additionally, ab initio molecular dynamics (AIMD) calculations results show that Li-decorated B2O monolayer has good reversible adsorption performance for H2 molecules. Furthermore, the Bader charge and density of states (DOS) analysis demonstrate H2 molecules are physically absorbed on the Li atoms via the electrostatic interactions. This study suggests that Li-decorated B2O monolayer can be a promising hydrogen storage material. 相似文献
103.
《International Journal of Hydrogen Energy》2021,46(69):34356-34361
This study investigates the ability of hydrogen (H2) to wet clay surfaces in the presence of brine, with implications for underground hydrogen storage in clay-containing reservoirs. Rather than measuring contact angles directly with hydrogen gas, a suite of other gases (carbon dioxide (CO2), argon (Ar), nitrogen (N2), and helium (He)) were employed in the gas-brine-clay system under storage conditions (moderate temperature (333 K) and high pressures (5, 10, 15, and 20 MPa)), characteristic of a subsurface environment with a shallow geothermal gradient. By virtue of analogies to H2 and empirical correlations, wettabilities of hydrogen on three clay surfaces were mathematically derived and interpreted. The three clays were kaolinite, illite, and montmorillonite and represent 1:1, 2:1 non-expansive, and 2:1 expansive clay groups, respectively. All clays showed water-wetting behaviour with contact angles below 40° under all experimental set-ups. It follows that the presence of clays in the reservoir (or caprock) is conducive to capillary and/or residual trapping of the gas. Another positive inference is that any tested gas, particularly nitrogen, is suitable as cushion gas to maintain formation pressure during hydrogen storage because they all turned out to be more gas-wetting than hydrogen on the clay surfaces; this allows easier displacement and/or retrieval of hydrogen during injection/production. One downside of the predominant water wettability of the clays is the upstaged role of biogeochemical reactions at the wetted brine-clay/silicate interface and their potential to affect porosity and permeability. Water-wetting decreased from kaolinite as most water-wetting clay over illite to montmorillonite as most hydrogen-wetting clay. Their wetting behaviour is consistent with molecular dynamic modelling that establishes that the accessible basal plane of kaolinite's octahedral sheet is highly hydrophilic and enables strong hydrogen bonds whereas the same octahedral sheet in illite and montmorillonite is not accessible to the brine, rendering these clays less water-wetting. 相似文献
104.
The effect of charge on the dihydrogen storage capacity of Sc2–C6H6 has been investigated at B3LYP-D3/6-311G(d,p) level. The neutral system Sc2–C6H6 can store 8H2 with gravimetric density of 8.76 wt %, and one H2 dissociates and bonds atomically on the scandium atom. The adsorption of 8H2 on Sc2–C6H6 is energetically favorable below 155 K. The atom-centered density matrix propagation (ADMP) molecular dynamics simulations show that Sc2–C6H6 can adsorb 3H2 within 1000 fs at 300K. Compared with Sc2–C6H6, the charged systems can adsorb more hydrogen molecules with higher gravimetric density, and all the H2 are adsorbed in the molecular form. The gravimetric densities of Sc2–C6H6+ and Sc2–C6H62+ are 9.75 and 10.71 wt%. Moreover, the maximum adsorption of charged systems are favorable in wider temperature range. Most importantly, the ADMP-MD simulations indicate that Sc2–C6H62+ can adsorb 6 hydrogen molecules within 1000 fs at 300K. It can be found that the gravimetric density (6.72 wt%) of Sc2–C6H62+ still exceeds the target of US Department of Energy (DOE) under ambient conditions. 相似文献
105.
Hongwei Shang Yaqin Li Yanghuan Zhang Dongliang Zhao Yan Qi Xiaoyi Xu 《International Journal of Hydrogen Energy》2021,46(34):17840-17852
In order to improve the hydrogen storage performances of TiFe-based alloys, a new type of TiFe0.8-mNi0.2Com (m = 0, 0.03, 0.05 and 0.1) alloys were prepared through vacuum medium-frequency induction melting. XPS results showed that the composition of surface oxide film contains TiO2, FeO and NiO for the cobalt-free alloy, and it also includes CoO and Co3O4 besides the above oxides for the cobalt-containing alloys. The activation temperature is 523, 403, 383 and 373 K for the TiFe0.8-mNi0.2Com (m = 0, 0.03, 0.05 and 0.1) alloys, respectively. The changes of the composition and microstructure of the surface oxide film are the root causes of the reduction of the activation temperature. XRD and SEM analyses showed that all the alloys are composed of the majority phase of TiFe phase and non-hydrogenated phase of Ti2Fe phase. Adding appropriate amount of cobalt is beneficial to inhibiting the generation of Ti2Fe phase and increasing the cell volume of TiFe phase. The hydrogenation capacity is proportional to the content of TiFe phase, which is 1.11, 1.48, 1.54 and 1.29 wt% for the TiFe0.8-mNi0.2Com (m = 0, 0.03, 0.05 and 0.1) alloys at 313 K, respectively. The hydrogenation plateau performance also is improved correspondingly. 相似文献
106.
Ionela-Dorina Dumbrava Calin-Cristian Cormos 《International Journal of Hydrogen Energy》2021,46(45):23149-23163
Hydrogen production by biogas conversion represent a promising solution for reduction of fossil CO2 emissions. In this work, a detailed techno-economic analysis was performed for decarbonized hydrogen production based on biogas conversion using calcium and chemical looping cycles. All evaluated concepts generate 100,000 Nm3/h high purity hydrogen. As reference cases, the biogas steam reforming design without decarbonization and with CO2 capture by gas-liquid chemical absorption were also considered. The results show that iron-based chemical looping design has higher energy efficiency compared with the gas-liquid absorption case by 2.3 net percentage points as well as a superior carbon capture rate (99% vs. 65%). The calcium looping case shows a lower efficiency than chemical scrubbing, with about 2.5 net percentage points, but the carbon capture rate is higher (95% vs. 65%). The hydrogen production cost increases with decarbonization, the calcium looping shows the most favourable situation (37.14 €/MWh) compared to the non-capture steam reforming case (33 €/MWh) and MDEA and iron looping cases (about 42 €/MWh). The calcium looping case has the lowest CO2 avoidance cost (10 €/t) followed by iron looping (20 €/t) and MDEA (31 €/t) cases. 相似文献
107.
Dionissios D. Papadias Jui-Kun Peng Rajesh K. Ahluwalia 《International Journal of Hydrogen Energy》2021,46(47):24169-24189
Recognizing the potential role of liquid hydrogen carriers in overcoming the inherent limitations in transporting and storing gaseous and liquid hydrogen, a complete production and use scenario is postulated and analyzed for perspective one-way and two-way carriers. The carriers, methanol, ammonia and toluene/MCH (methylcyclohexane), are produced at commercially viable scales in a central location, transmitted by rail or pipelines for 2000 miles, and decomposed near city gates to generate fuel-cell quality hydrogen for distribution to refueling stations. In terms of the levelized cost of H2 distributed to the stations, methanol is less expensive to produce ($1.22/kg-H2) than MCH ($1.35/kg-H2) or ammonia ($2.20/kg-H2). Levelized train transmission cost is smaller for methanol ($0.63/kg-H2) than ammonia ($1.29/kg-H2) or toluene/MCH system ($2.07/kg-H2). Levelized decomposition cost is smaller for ammonia ($0.30–1.06/kg-H2) than MCH ($0.54–1.22/kg-H2) or methanol ($0.43–1.12/kg-H2). Over the complete range of demand investigated, 10–350 tpd-H2, the levelized cost of H2 distributed to stations is aligned as methanol « ammonia ~ MCH. With pipelines at much larger scale, 6000 tpd-H2, the levelized cost decreases by ~1 $/kg-H2 for ammonia and MCH and much less for methanol. Methanol is a particularly attractive low-risk carrier in the transition phase with lower than 50-tpd H2 demand. 相似文献
108.
Peng Gao Ji-wen Li Jie Zhang Guangzhao Wang 《International Journal of Hydrogen Energy》2021,46(42):21739-21747
Density functional theory (DFT) computational studies were conducted to explore the hydrogen storage performance of a monolayer material that is built on the base of carbon nitride (g-C3N4, heptazine structure) with decoration by magnesium (Mg). We found that a 2 × 2 supercell can bind with four Mg atoms. The electronic charges of Mg atoms were transferred to the g-C3N4 monolayer, and thus a partial electropositivity on each adsorbed Mg atom was formed, indicating a potential improvement in conductivity. This subsequently causes the hydrogen molecules’ polarization, so that these hydrogen molecules can be efficiently adsorbed via both van der Waals and electrostatic interactions. To note, the configurations of the adsorbed hydrogen molecules were also elucidated, and we found that most adsorbed hydrogen molecules tend to be vertical to the sheet plane. Such a phenomenon is due to the electronic potential distribution. In average, each adsorbed Mg atom can adsorb 1–9 hydrogen molecules with adsorption energies that are ranged from ?0.25 eV to ?0.1 eV. Moreover, we realised that the nitrogen atom can also serve as an active site for hydrogen adsorption. The hydrogen storage capacity of this Mg-decorated g-C3N4 is close to 7.96 wt %, which is much higher than the target value of 5.5 wt % proposed by the U.S. department of energy (DOE) in 2020 [1]. The finding in this study indicates a promising carbon-based material for energy storage, and in the future, we hope to develop more advanced materials along this direction. 相似文献
109.
Luhui Han Huogen Huang Pengguo Zhang Ce Ma Xuefeng Wang Ge Sang Wenhua Luo 《International Journal of Hydrogen Energy》2021,46(2):2312-2321
To further explore the application feasibility of Zr2Co alloy in tritium-related fields, hydrogenation/dehydrogenation properties of this material of crystalline or amorphous structure, prepared by arc melting or melt spinning, were studied by pressure-composition temperature measurement, X-ray diffraction, differential scanning calorimeter, thermal desorption spectroscopy. It was found that the two kinds of Zr2Co alloys can absorb hydrogen in a close full concentration of ~9 mmol/g, and may have similar equilibrium hydrogen pressure in the order of 10?6 Pa at room temperature. In their hydrogenated samples various hydrides were observed to form, including ZrH2, Zr2CoH5, ZrCoH3 and an amorphous one with gradually decreasing general thermostability. The amorphous alloy exhibited easier hydrogen induced disproportionation caused by highly stable ZrH2 and much slower hydrogen absorption kinetics. This disproportionation behavior of the crystalline alloy was found to be entirely suppressed by changing heating process. The results firmly indicate that crystalline Zr2Co alloy could be more favorable for tritium treatment due to very low equilibrium pressure and the feasibility of eliminating the disproportionation. 相似文献
110.