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![Types and applications of fuel cells [1].](publication/354604405/figure/fig5/AS:1068327787040769@1631720601053/Types-and-applications-of-fuel-cells-1.png)
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![Figure 5. Energy transition [7].](publication/354604405/figure/fig1/AS:1068327782842368@1631720600915/Energy-transition-7_Q320.jpg)
![Figure 5. Energy transition [7]. Energies 2021, 14, x FOR PEER REVIEW 8...](publication/354604405/figure/fig2/AS:1068327782862848@1631720600953/Energy-transition-7-Energies-2021-14-x-FOR-PEER-REVIEW-8-of-22_Q320.jpg)
![Figure 6. Types of reactions [7].](publication/354604405/figure/fig3/AS:1068327782846465@1631720600983/Types-of-reactions-7_Q320.jpg)
![Figure 10. Electrolytes of an Alkaline and a PEM fuel cell [17].](publication/354604405/figure/fig4/AS:1068327787061248@1631720601011/Electrolytes-of-an-Alkaline-and-a-PEM-fuel-cell-17_Q320.jpg)
![Figure 14. Types and applications of fuel cells [1].](publication/354604405/figure/fig5/AS:1068327787040769@1631720601053/Types-and-applications-of-fuel-cells-1_Q320.jpg)
This paper covers the hydrogen technologies regarding the role of hydrogen as an energy carrier and the possibilities of its production and use. It is initially presented the modalities and the efficiency of the current technologies of obtaining hydrogen, detailing its obtaining by the electrolysis of the water, the electrochemical efficiency and t...
Citations
... The constantly increasing global concern regarding climate change caused by anthropogenic CO 2 emission has resulted in great attention given to hydrogen as one of the possible solutions [1]. Hydrogen utilization is discussed and slowly implemented in almost every crucial area, e.g., automotive industry [2,3], railway transport [4], household applications [5,6], energy production and storage [7], and heavy industry [8]. In these scenarios, the most-common assumption is that the hydrogen origin is green, meaning it is produced with the use of electrolysis. ...
With the increasing role of hydrogen in the global market, new ways of hydrogen production are being sought and investigated. One of the possible solutions might be the plasma pyrolysis of methane. This approach provides not only the desired hydrogen, but also valuable carbon-containing products, e.g., carbon black of C2 compounds. This review gathers information from the last 20 years on different reactors that were investigated in the context of methane pyrolysis, emphasizing the different products that can be obtained through this process.
... Its calorific value is high, reaching 122 MJ/kg, which is almost three times higher than that of oil [4]. It can be used in direct combustion processes, cogeneration systems, fuel cells for electricity production, or hydrogenation processes of conventional fuels [5]. The final outcome of its energy conversion is water vapor, which is of great importance considering the need to reduce greenhouse gas emissions into the atmosphere [6]. ...
Though deemed a prospective method, the bioconversion of organic waste to biohydrogen via dark fermentation (DF) has multiple drawbacks and limitations. Technological difficulties of hydrogen fermentation may, in part, be eliminated by making DF a viable method for biohythane production. Aerobic granular sludge (AGS) is a little-known organic waste spurring a growing interest in the municipal sector; its characteristics indicate the feasibility of its use as a substrate for biohydrogen production. The major goal of the present study was to determine the effect of AGS pretreatment with solidified carbon dioxide (SCO2) on the yield of H2 (biohythane) production during anaerobic digestion (AD). It was found that an increasing dose of SCO2 caused an increase in concentrations of COD, N-NH4+, and P-PO43− in the supernatant at the SCO2/AGS volume ratios from 0 to 0.3. The AGS pretreatment at SCO2/AGS ratios within the range of 0.1–0.3 was shown to enable the production of biogas with over 8% H2 (biohythane) content. The highest yield of biohythane production, reaching 481 ± 23 cm3/gVS, was obtained at the SCO2/AGS ratio of 0.3. This variant produced 79.0 ± 6% CH4 and 8.9 ± 2% H2. The higher SCO2 doses applied caused a significant decrease in the pH value of AGS, modifying the anaerobic bacterial community to the extent that diminished anaerobic digestion performance.
... In this study, the system was designed to use recycled water in the step of washing plastics to save water. The amount of energy needed was calculated by collecting the data from previous studies (Badea, 2021;Gandia et al, 2013) and from the specs of the plastic washing recycling line machine LDW1500 and Baulin Aerobic Bioreactor. Aerobic microbial biodegradation rates of the plastics were obtained from the literature and presented in Table 2. ...
... Therefore, the amount of hydrogen produced can meet electricity demand. According to Badea (2021), the electricity requirement is 50 kWh to produce 1 kg of hydrogen. In this study, it was found that the total energy requirement for the electrolysis process was 3.07 × 10 12 kWh. ...
Plastic waste collected from the landfills may be washed, shredded, digested by plastic-eating microorganisms centrifuged and sent back to the landfill. If the generated water should be electrolysed, in the case of processing 10% of the annually generated plastic waste, 24.2 Mt of plastic may be eliminated and 2.4 × 103 kWh of energy may be recovered with the energy recovery ratio of 0.8. This ratio would be 2 in the case of pyrolysis, indicating that pyrolysis may be 2.5 folds more efficient than the microbial process. Moreover, pyrolysis occurs at high temperatures and is much faster than the microbial process. If we can find a safe way to innoculate the dump sides with the plastic digesting microorganisms, hydrogen may be generated without the production of carbon dioxide and water; the plastic waste may be reduced in the long run.
... Hydrogen also has a higher energy density on a mass basis compared to other fuels and it emits very low levels of global greenhouse gas emissions (CO 2 , NO x , etc.) when used as a fuel. Moreover, it has 3.06 times higher average heating value than methane, gasoline, and coal [6,7]. Hydrogen can be obtained from both renewable and nonrenewable sources, and it can be converted the chemical energy of hydrogen into electrical energy via fuel cells (FCs) [8]. ...
Additive manufacturing (AM), a three-dimensional (3D) printing method has attracted great attention in manufacturing technology because of the low cost of fabrication of medium to small sizes of products, fast prototyping, and high precision. The 3D printing method has emerged as an innovative interface in electrode applications due to the opportunity to use conductive Polylactic Acid (PLA) filaments. In this study, Nickel (Ni)
and Platinum (Pt) with different metal ratios were deposited on 3D printed electrodes and prepared using conductive graphene-based PLA filament. Then, the NiPt coated 3D printed graphene-based electrodes were modified by different metal ratios of Ni/Pt: 1:1, 1:2, and 1:3, called NiPt1, NiPt2, and NiPt3, respectively. The physical properties of the NiPt coated 3D printed electrodes were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), FE-SEM/Energy Dispersive X-ray Spectroscopy (FE-SEM/EDX), FE-SEM mapping, X-ray Powder Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS) techniques. Electrochemical measurements of the electrodes were examined by using Linear Sweep Voltammetry (LSV), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS), Tafel polarization analysis and Chronoamperometry (CA) techniques. The results showed that on NiPt3 3D printed electrode surface, the current density was improved by 25% compared to the other electrode samples. Moreover, it was found that the NiPt3 coated 3D printed electrode had 1.5 times higher current density than the NiPt1 coated 3D printed electrode for HER.
... In this study, the system was designed to use recycled water in the step of washing plastics to save water. The amount of energy needed was calculated by collecting the data from previous studies (Badea, 2021;Gandia et al, 2013) and from the specs of the plastic washing recycling line machine LDW1500 and Baulin Aerobic Bioreactor. Aerobic microbial biodegradation rates of the plastics were obtained from the literature and presented in Table 2. ...
... Therefore, the amount of hydrogen produced can meet electricity demand. According to Badea (2021), the electricity requirement is 50 kWh to produce 1 kg of hydrogen. In this study, it was found that the total energy requirement for the electrolysis process was 3.07 × 10 12 kWh. ...
Plastic waste collected from the landfills may be washed, shredded, digested by plastic-eating microorganisms centrifuged and sent back to the landfill. If the generated water should be electrolyzed, in the case of processing 10% of the annually generated plastic waste, 24.2 Mt of plastic may be eliminated and 2.4 x103 kWh of energy may be recovered with the energy recovery ratio of 0.8. This ratio would be 2 in the case of pyrolysis, indicating that pyrolysis may be 2.5 folds more efficient than the microbial process. Moreover, pyrolysis occurs at high temperatures and is much faster than the microbial process. If we can find a safe way to innoculate the dump sides with the plastic digesting microorganisms, hydrogen may be generated without the production of carbon dioxide and water, the plastic waste may be reduced in the long run.
... In this study, the system was designed to use recycled water in the step of washing plastics to save water. The amount of energy needed was calculated by collecting the data from previous studies (Badea, 2021;Gandia et al, 2013) and from the specs of the plastic washing recycling line machine LDW1500 and Baulin Aerobic Bioreactor. Aerobic microbial biodegradation rates of the plastics were obtained from the literature and presented in Table 2. ...
... Therefore, the amount of hydrogen produced can meet electricity demand. According to Badea (2021), the electricity requirement is 50 kWh to produce 1 kg of hydrogen. In this study, it was found that the total energy requirement for the electrolysis process was 3.07 × 10 12 kWh. ...
Plastic waste collected from the landfills may be washed, shredded, digested by plastic-eating microorganisms centrifuged and sent back to the landfill. If the generated water should be electrolyzed, in the case of processing 10% of the annually generated plastic waste, 24.2 Mt of plastic may be eliminated and 2.4 x103 kWh of energy may be recovered with the energy recovery ratio of 0.8. This ratio would be 2 in the case of pyrolysis, indicating that pyrolysis may be 2.5 folds more efficient than the microbial process. Moreover, pyrolysis occurs at high temperatures and is much faster than the microbial process. If we can find a safe way to innoculate the dump sides with the plastic digesting microorganisms, hydrogen may be generated without the production of carbon dioxide and water, the plastic waste may be reduced in the long run.
... Currently, the contradiction between the decreasing of global fossil energy and the infinite demand for energy is the main factor that restricts the sustainable development of society [1,2]. Hydrogen energy is considered to be the most potential energy carrier for replacing traditional fossil fuels in the future because of its advantages such as abundant reserves, high energy density (142 MJ/kg), environmental protection, and renewability [3][4][5][6]. Hydrogen fuel cell is the most attractive new energy, and its "fuel" is hydrogen, so efficient and safe hydrogen generation technology is particularly important [7]. Hydrogen generation by hydrolysis is a kind of on-site hydrogen generation method, which can be easily applied to various mobile devices [8][9][10]. ...
As a most promising material for hydrogen generation by hydrolysis, magnesium hydride (MgH2) is also trapped by its yielded byproduct Mg(OH)2 whose dense passivated layers prevent the further contact of intimal MgH2 with water. In this work, LiH, as a destroyer, has been added to promote the hydrogen properties of MgH2. The results demonstrate that even 3 wt % LiH was added into MgH2-G, the hydrogen generation yield can increase about 72% compared to the hydrogen generation yield of MgH2-G. The possible mechanism is that Mg2+ from the hydrolysis of MgH2 preferentially bound with OH− ions from the hydrolysis of LiH to form Mg(OH)2 precipitation, which is dispersed in water rather than coated on the surface of MgH2. Moreover, adding MgCl2 into hydrolysis solution, using ball milling technology, and increasing the hydrolysis temperature can make the hydrolysis rate higher and reaction process more complete. It is noted that a too high weight ratio of LiH with too high of a hydrolysis temperature will make the reaction too violent to be safe in the experiment. We determinate the best experimental condition is that the LiH ratio added into MgH2 is 3 wt %, the hydrolysis temperature is 60 °C, and the concentration of MgCl2 hydrating solution is 1 M. MgH2-LiH composite hydrogen generation technology can meet the needs of various types of hydrogen supply and has broad application prospects.
The paper adopts an interdisciplinary approach to comprehensively review the current knowledge in the field of porous geological materials for hydrogen adsorption. It focuses on detailed analyses of the adsorption characteristics of hydrogen in clay minerals, shale, and coal, considering the effect of factors such as pore structure and competitive adsorption with multiple gases. The fundamental principles underlying physically controlled hydrogen storage mechanisms in these porous matrices are explored. The findings show that the adsorption of hydrogen in clay minerals, shale, and coal is predominantly governed by physical adsorption that follows the Langmuir adsorption equation. The adsorption capacity decreases with increasing temperature and increases with increasing pressure. The presence of carbon dioxide and methane affects the adsorption of hydrogen. Pore characteristics—including specific surface area, micropore volume, and pore size—in clay minerals, shale, and coal are crucial factors that influence the adsorption capacity of hydrogen. Micropores play a significant role, allowing hydrogen molecules to interact with multiple pore walls, leading to increased adsorption enthalpy. This comprehensive review provides insights into the hydrogen storage potential of porous geological materials, laying the groundwork for further research and the development of efficient and sustainable hydrogen storage solutions.
