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1.
《International Journal of Hydrogen Energy》2022,47(67):28932-28944
Cryo-compressed hydrogen (CcH2) is a promising hydrogen storage method with merits of high density with low power consumption. Thermodynamic analysis and comparison of several CcH2 processes are conducted in this paper, under hydrogen storage conditions of 10–100 MPa at 60–100 K. Mixed-refrigerant J-T (MRJT), nitrogen/neon reverse Brayton (RBC) and hydrogen expansion are employed for cooling hydrogen, respectively. Combined CcH2 processes such as MRJT + neon-RBC are proposed to reach higher CcH2 density at lower temperatures (<80 K). It was indicated that the specific power consumptions (SPC) of MRJT processes are obviously lower than those of nitrogen/neon-RBC or hydrogen expansion processes. For a typical storage condition of 50 MPa at 80 K, MRJT CcH2 process could achieve hydrogen density of 71.59 kg m?3, above liquid hydrogen. While its SPC of 6.42 kWh kg?1 is about 40% lower than current dual-pressure Claude hydrogen liquefaction processes (10.85 kWh kg?1). 相似文献
2.
Performances comparison of adsorption hydrogen storage tanks at a wide temperature and pressure zone
《International Journal of Hydrogen Energy》2023,48(69):26881-26893
Large-scale application of hydrogen requires safe, reliable and efficient storage technologies. Among the existing hydrogen storage technologies, cryo-compressed hydrogen (CcH2) storage has the advantages of high hydrogen storage density, low energy consumption and no ortho-para hydrogen conversion. But it still needs higher hydrogen storage pressure when reaching higher hydrogen storage density. In order to reduce hydrogen storage pressure and improve storage density, solid adsorption technology is introduced in CcH2. Activated carbon and metal-organic framework materials (MOFs) are employed as adsorbents in this paper. The gravimetric/volumetric hydrogen storage capacities of different adsorption tanks are studied and compared with the hydrogen storage conditions of 1–55 MPa at 77–298 K. The results show that the hydrogen storage density of CcH2 combined with adsorption is higher than that of pure adsorption hydrogen storage, and the storage pressure is lower than that of pure CcH2 under the same hydrogen storage capacity. And the combination of two hydrogen storage technologies can achieve a high hydrogen storage capacity equivalent to that of liquid hydrogen at a lower pressure. 相似文献
3.
《International Journal of Hydrogen Energy》2019,44(33):18179-18192
Hydrogen storage technology is essentially necessary to promote renewable energy. Many kinds of hydrogen storage materials, which are hydrogen storage alloys, inorganic chemical hydrides, carbon materials and liquid hydrides have been studied. In those materials, ammonia (NH3) is easily liquefied by compression at 1 MPa and 298 K, and has a highest volumetric hydrogen density of 10.7 kg H2/100 L. It also has a high gravimetric hydrogen density of 17.8 wt%. The theoretical hydrogen conversion efficiency is about 90%. NH3 is burnable without emission of CO2 and has advantages as hydrogen and energy carriers. 相似文献
4.
《International Journal of Hydrogen Energy》2023,48(75):29058-29070
A simple oxidative polymerization approach has been used to synthesize MoO3/PANI hybrid composite for energy conversion and storage application. In this carbon-free energy conversion process, as-developed electrocatalyst (MoO3/PANI hybrid composite) has significantly improved the molecular hydrogen generation via electro-reduction of protons. The hydrogen evolution kinetics parameters, overpotential at 10 mA cm−2 is ∼110 mV and Tafel slope 132 mV/dec have been obtained for the as-developed catalyst which suggests the reaction is controlled by Volmer-limited reaction step. Further the as-developed material has been tested for energy storage application and exhibited specific capacitance of 680 F. g−1. 相似文献
5.
《International Journal of Hydrogen Energy》2019,44(50):27214-27223
Transition metal phosphides are very attractive because of the remarkable performance in energy storage and conversion. Herein, a series of bimetallic phosphides are synthesized through a one-step solid-state reaction. The obtained bimetallic phosphides show outstanding properties as supercapacitor electrode materials. Results show that the incorporation of secondary metal into phosphides tunes composition, electronic structure and then the electrochemical performance. And electrochemical properties are closely associated with the secondary metal content. Notably, the obtained NiCoP shows the best performance with 2011 F g−1 at 1 A g−1. And an asymmetric supercapacitor (ASC) based on NiCoP shows energy density of 47.6 W h kg−1, along with 90.5% of capacitance maintained after 10000 cycles. In addition, the NiCoP also possesses great performance toward hydrogen evolution reaction (HER), which displays the lowest potential of 0.221 V vs. RHE and 0.173 V vs. RHE at 10 mA cm−2 in 0.5 M H2SO4 as well as 1.0 M KOH, respectively. The excellent properties may result from the enhanced electrical conductivity, synergistic effects among metal elements and the increased local electrical dipole. The regulation of electronic structure through introduction of secondary metal atom sheds considerable light on realization and preparation of the bimetallic transition metal compounds as electrode materials. 相似文献
6.
The production of hydrogen from Organic Fraction of Solid Municipal Waste (OFSMW) was studied on a semi-pilot scale. The potential of generating electricity using the process effluents was further assessed using a two-chambered Microbial Fuel Cell. A maximum hydrogen fraction of 46.7% and hydrogen yield of 246.93 ml H2 g−1 Total Volatile Solids was obtained at optimum operational setpoints of 7.9, 30.29 °C and 60 h for pH, temperature and hydraulic retention time (HRT) respectively. A maximum electrical power density of 0.21 W m-2 (0.74 A m−2) was recorded at 500 Ω and the chemical oxygen demand (COD) removal efficiency of 50.1% was achieved from the process. The process economics of energy generation from organic wastes could be significantly improved by integrating a two-stage process of fermentative hydrogen production and electricity generation. 相似文献
7.
《International Journal of Hydrogen Energy》2023,48(42):15809-15816
Herein, CoO and CoMoO4 heterostructure supported on nickel foam (CoO/CoMoO4@NF) are proposed as an effective bifunctional hydrogen evolution reaction (HER) and hydroxide reaction (HOR) electrocatalyst. The electron density distribution at the interface can be optimized by coupling CoO and CoMoO4, thereby improving conductivity and regulating the hydrogen binding energy (HBE) and hydroxyl binding energy (OHBE). CoO/CoMoO4@NF exhibits high stability and activity with an exchange current density of ∼3.67 mA cm−2. Co/CoMoO4@NF reaches the current density of −10 mA cm−2 at only −29 mV and the corresponding Tafel slope of 40.2 mV dec−1. This work provides a promising solution for non-precious metal catalyst for hydrogen reaction in energy storage. 相似文献
8.
《International Journal of Hydrogen Energy》2019,44(28):14258-14265
Exploring highly active and stable electrocatalysts toward hydrogen evolution reaction (HER) is vital for the production of green energy and storage of intermittently renewable electrical energy. In this study, we fabricate Pt-modified Ni(OH)2 on 3D nickel foam (Pt content: 1.5 wt %) via a one-step galvanic replacement reaction in aqueous solution to achieve a top performance of HER under alkaline conditions. It exhibits a negligible onset potential, a Tafel slope of 17 mV dec−1, and overpotentials of 38, 114, and 203 mV to deliver 10, 50, and 100 mA cm−2 current densities, respectively, which outperforms the commercial Pt/C and Pt sheet. Moreover, this catalyst shows enhanced durability towards HER, sustaining electrolysis at −20 mA cm−2 for 4, 500 min in 1 M KOH with little degradation. Its good performances come from the synergism of flake-like Pt and amorphous Ni(OH)2. This work provides not only a facile and easy scale-up approach to fabricate Pt−modified electrocatalysts with improved HER performance but also a new strategy to design self-supported high-performance hybrid materials of noble-metal and amorphous transitional metal hydroxides for sustainable energy conversion and storage. 相似文献
9.
We prepared activated carbons (ACs) that are among the best adsorbents for hydrogen storage. These ACs were prepared from anthracites and have surface areas (SBET) as high as 2772 m2 g−1. Anthracites activated with KOH presented the highest adsorption capacities with a maximum of 5.3 wt.% at 77 K and 4 MPa. Non-linearity between hydrogen uptake at 77 K and pore texture was confirmed, as soon as their SBET exceeded the theoretical limiting value of (geometrical) surface area, i.e., SBET > 2630 m2 g−1. We separated adsorption and compression contributions to total hydrogen storage. The amount of hydrogen stored is significantly increased by adsorption only at moderate pressure: 3 MPa and 0.15 MPa at 298 and 77 K, respectively. Hydrogen adsorption on ACs at high pressure, above 30 MPa at 298 K and 8 MPa at 77 K, has not interest because more gas can be stored by simply compression in the same tank volume. 相似文献
10.
Metal hydride material properties required for on-board hydrogen storage for use with automotive polymer electrolyte fuel cell systems are discussed. Thermodynamic relationships between enthalpy and entropy of sorption are determined such that the storage system can be thermally integrated with the fuel cell system and be refueled at reasonable H2 supply pressures of 50–200 atm. Simple criteria are developed for specifying minimum discharge kinetic rates needed to satisfy hydrogen demand on automotive duty cycles. Simple criteria are also developed for specifying minimum charge kinetic rates needed to refuel metal hydride tanks in reasonable time. Accessible intrinsic capacity and bulk density of the metal hydride are determined for the storage system to achieve system level targets for gravimetric and volumetric capacities. Based on these analyses, it is recommended that the storage media properties be measured on samples prepared by mixing the metal hydride with a high thermal conductivity material, and compacted to 600 kg m−3 bulk density. The compact should have a minimum effective thermal conductivity of 8.5 W m−1 K−1. 相似文献
11.
《International Journal of Hydrogen Energy》2020,45(8):5202-5215
Biohydrogen is considered as fuel of future owing to its distinctive attribute for clean energy generation, waste management and high energy content. Suitable feedstock play important role for achieving high rate hydrogen production via dark fermentation process. In this regard, different organic wastes such as cane molasses, distillery effluent and starchy wastewater were examined as potential substrates for biohydrogen production by Enterobacter cloacae IIT-BT 08. Groundnut deoiled cake (GDOC) was considered as additional nutritional supplement to enhance biohydrogen yields. The maximum hydrogen yield of 12.2 mol H2 kg−1 CODremoved was obtained using cane molasses and GDOC as co-substrates. To further ensure reliability of the process, bench (50 L) and pilot scale (10000 L) bioreactors were customized and operated. The pilot scale study achieved 76.2 m3 hydrogen with a COD removal and energy conversion efficiency of 18.1 kg m−3 and 37.9%, respectively. This study provides an extensive strategy in moving from lab to pilot scale biohydrogen production thereby, providing further opportunity for commercial exploitation. 相似文献
12.
《International Journal of Hydrogen Energy》2019,44(13):6612-6617
The rational design of highly efficient electrocatalysts to generate hydrogen by catalyzing hydrogen evolution reaction still remains a challenge. Herein, we report a simple strategy to significantly enhance the catalytic activities of NiCo2O4 nanowire arrays by simply tuning the amount of oxygen vacancies. Remarkably, the oxygen-deficient NiCo2O4 catalysts obtained in Ar environment show significantly improved catalytic activities toward hydrogen evolution reaction with the requirement of 104 mV overpotential to afford 10 mA cm−2, 122 mV less than that for air-sintered NiCo2O4 (226 mV). Moreover, such catalysts also exhibit superior long-term durability for 24 h at 100 mA cm−2. The present study further promotes the application of NiCo2O4 in other energy storage and conversion system. 相似文献
13.
《International Journal of Hydrogen Energy》2019,44(51):27885-27895
Transition metals, including Ni, show good catalytic activity in the hydrogen storage reaction of Mg. In the present paper, first-principles calculation is performed to predict and analyze the hydriding reaction of Ni-incorporated Mg and experimental study is used to verify the accuracy of the forecast. Theoretical studies show that the hydriding reaction of Ni-incorporated Mg is a diffusion-controlled process. With Ni incorporation, the energy barrier of H2 dissociation is significantly decreased and the diffusion becomes the limiting step. Experimental studies confirm the results of theoretical studies. Besides, the material with Ni incorporation shows excellent activation performance and rapid absorption rates, leading to a high hydrogen content of 4.1 wt% in 60 s under 240 °C 3.0 MPa H2 and a low activation energy of 56.1 kJ mol−1 versus 0.4 wt% and 73.5 kJ mol−1 for the material without Ni incorporation. Atomic Ni only plays a role of catalyst. 相似文献
14.
《International Journal of Hydrogen Energy》2020,45(32):16239-16253
The present study discusses the thermodynamic compatibility criteria for the selection of metal hydride pairs for the application in coupled metal hydride based thermal energy storage systems. These are closed systems comprising of two metal hydride beds – a primary bed for energy storage and a secondary bed for hydrogen storage. The performance of a coupled system is analyzed considering Mg2Ni material for energy storage and LaNi5 material for hydrogen storage. A 3-D model is developed and simulated using COMSOL Multiphysics® at charging and discharging temperatures of 300 °C and 230 °C, respectively. The LaNi5 bed used for hydrogen storage is operated close to ambient temperature of 25 °C. The results of the first three consecutive cycles are presented. The thermal storage system achieved a volumetric energy storage density of 156 kWh m−3 at energy storage efficiency of 89.4% during third cycle. 相似文献
15.
《International Journal of Hydrogen Energy》2022,47(98):41648-41662
Hydrogen has the highest gravimetric energy density of all fuels; however, it has a low volumetric energy density, unfavorable for storage and transportation. Hydrogen is usually liquefied to meet the bulk transportation needs. The exothermic interconversion of its spin isomers is an additional activity to an already energy-intensive process. The most significant temperature drop occurs in the precooling cycle (between ?150 °C and up to ?180 °C) and consumes more than 50% of the required energy. To reduce the energy consumption and improve the exergy efficiency of the hydrogen liquefaction process, a new high-boiling component, Hydrofluoroolefin (HFO-1234yf), is added to the precooled mixed refrigerant. As a result, the specific energy consumption of precooling cycle reduces by 41.8%, from 10.15 kWh/kgLH2 to 5.90 kWh/kgLH2, for the overall process. The exergy efficiency of the proposed case increases by 43.7%; however, the total equipment cost is also the highest. The inflated cost is primarily due to the added ortho-to-para hydrogen conversion reactor, boosting the para-hydrogen concentration. From the perspective of bulk storage and transportation of liquid hydrogen, the simplicity of design and low energy consumption build a convincing case for considering the commercialization of the process. 相似文献
16.
《International Journal of Hydrogen Energy》2022,47(54):22832-22839
The gravimetric H2 densities and the heats of combustion of tanks stored ammonia (ammonia storage tanks) were similar to those of the liquid H2 tanks at the weight of 20–30ton, although the gravimetric H2 density of liquid H2 is 100 wt%. The volumetric H2 densities and the heats of combustion of ammonia storage tanks were about 2 times higher than those of liquid H2 tanks at 1–4 × 104 m3. Gray ammonia is synthesized from hydrogen through process known as steam methane reforming, nitrogen separated from air and Haber-Bosch process. Blue ammonia is the same as gray ammonia, but with CO2 emissions captured and stored. Green ammonia is produced by reacting hydrogen produced by electrolysis of water and nitrogen separated from air with Haber-Bosch process using renewable energies. The energy efficiencies of gray, blue and green ammonia were better than those of liquid hydrogen and methylcyclohexane (MCH) with high H2 density and similar to the efficiency of H2 gas. The energy efficiencies of ammonia decreased in the order, gray ammonia > blue ammonia > green ammonia. The production costs of green hydrogen energy carried increased in the order, ammonia < liquid H2<MCH. The amounts of energy consumption by N2 production and Haber-Bosch process were below 10% compared with the value of H2 production from water electrolysis. 相似文献
17.
《International Journal of Hydrogen Energy》2019,44(23):11695-11704
Hydrogen production through photocatalytic water splitting attracts great attention in fields of energy conversion. To improve the hydrogen evolution efficiency, narrowing the bandgap of photocatalysts by introducing dopant atoms is widely investigated for increasing light absorption. Herein, Mo-doped BaTiO3 samples are synthesized by a traditional solid-state reaction method and all the samples are modified with Pt by a photo-reduction method. Compared with pure BaTiO3, Mo doping into BaTiO3 samples realizes the band-to-band visible-light absorption and shows remarkable improvement in hydrogen production efficiency. Under simulated sunlight irradiation and with 0.4 wt% Pt deposition, BaTiO3 doped with 2 at% Mo exhibits a hydrogen evolution rate of 63 μmol g−1 h−1, about 2 times improvement in comparison to pure BaTiO3 (35 μmol g−1 h−1). Further first-principles calculations based on density-function theory demonstrates an apparent downward movement of the conduction band minimum due to the coupling between the Ti 3d and Mo 3d states, leading to the significant bandgap narrowing and enhancement of the visible-light photocatalytic activity. 相似文献
18.
《International Journal of Hydrogen Energy》2023,48(47):17868-17881
In this article, we report the preparation of novel cobalt iron phosphate nanoparticles which are self-assembled for energy storage, energy conversion, and sustainability. The self-assembled nanoparticles provide an efficient pathway for the transfer of electrons from the bulk of the materials to the interface of the electrode. This hypothesis has been derived from the analysis based on the electrochemical results for the supercapacitor-based energy storage and hydrogen evolution. The electrode consisting of self-assembled nanoparticles exhibits a maximum specific capacity of 280 C g−1 at a specific current of 1 A g−1. The cyclic voltammetric results suggest the prominent charge storage is by the faradaic reaction which has been concluded from Dunn's approach. The supercapattery device utilizing activated carbon (AC) as the negative electrode and cobalt iron phosphate as the positive electrode exhibit a specific capacity of 210 C g−1 at 2 A g−1 while the specific energy of 47.6 Wh kg-1 at 1.6 kW kg−1. Furthermore, the electrode actively catalyzes the electrochemical hydrogen evolution reaction and it can be lowering the overpotential required by the hydrogen generation. It exhibits the overpotential of 197 mV while the electrode represents the long-time (24 h) consistency for hydrogen production. These results indicate that the novel cobalt iron phosphate nanoparticles could be a potential candidate for energy storage and conversion purposes. 相似文献
19.
《International Journal of Hydrogen Energy》2019,44(12):5940-5947
Hydrogen oxidation reaction (HOR) can be applied to proton exchange membrane fuel cells to generate electrical energy and anode discharge. Due to its special properties, RuO2 has been applied to supercapacitors, phenolic wastewater, textile industry wastewater, and degrading organic substances. However, there is few reports on the application of the RuO2 catalyst to hydrogen oxidation reaction (HOR). In this study, we successfully obtained RuO2 NPs using a simple and eco-friendly hydrothermal method. Furthermore, the electrochemical activity of RuO2 NPs prepared at different concentration (0.15 M, 0.20 M) and different hydrothermal temperature (150 °C, 160 °C, and 170 °C) was evaluated by the hydrogen oxidation reaction. The particle size, composition, dispersion and morphology of the obtained RuO2 catalysts were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). In addition, cyclic voltammograms (CV) were utilized to investigate the electrochemical activity of the RuO2 catalysts. The results showed that the obtained catalyst at a hydrothermal temperature of 160 °C and a concentration of 0.15 M displayed a Brunauer-Emmett-Teller (BET) surface area of 26.74 m2 g−1. Meanwhile, the catalyst had a uniform distribution. The hydrogen oxidation current density of the obtained RuO2 catalysts is upto 6 mA cm−2, showing a good electrochemical activity for hydrogen oxidation reaction. 相似文献
20.
《International Journal of Hydrogen Energy》2020,45(58):33832-33845
Mechanical milling is widely recognized as the best method to prepare nano-structured magnesium based hydrogen storage materials. The composites La7Sm3Mg80Ni10 + 5 wt% TiO2 (named La7Sm3Mg80Ni10–5TiO2) whose structures are nano-crystal and amorphous accompanied by great hydrogen absorption and desorption properties were fabricated by mechanical milling. The research focuses on the effect of milling duration on the thermodynamics and dynamics. The instruments of researching the gaseous hydrogen storing performances include Sievert apparatus, DSC and TGA. The calculation of dehydrogenation activation energy was realized by applying Arrhenius and Kissinger formulas. The calculation results show the specimen milled for 10 h exhibits the optimal activation performance and hydrogenation and dehydrogenation kinetics. Extending or shrinking the milling duration will lead to the degradation of hydrogen storage performances. The as-milled (10 h) alloy at the full activated state can absorb 4 wt% hydrogen in 87 s at 473 K and 3 MPa and release 3 wt% H2 in 288 s at 573 K and 1 × 10−4 MPa. The changed milling durations have little impact on the thermodynamic properties of experimental samples and the enthalpy change (ΔH) of the alloy milled for 10 h is 74.23 kJ/mol. Moreover, it is found that the as-milled (10 h) alloy displays the minimum apparent activation energy of dehydrogenation (59.1 kJ/mol), suggesting the optimal hydrogen storing property of the as-milled (10 h) alloy. 相似文献