Papers by Keyword: Hydrogen Production

Abstract: Environmental concerns have driven the quest for clean energy solutions, with green hydrogen emerging as promising choice. This paper underscores various production methods for green hydrogen, examining their relevance and providing an overview of the utilization of Morocco's renewable energies in its production. Key challenges will be given, including water scarcity, storage, and transportation. Overall, this paper delivers a comprehensive assessment of the role of green hydrogen in Morocco’s energy transformation.

Abstract: In this study, a supercritical metal-water reactor for hydrogen production was designed, simulated, and analysed. As the world urgently seeks to transition towards sustainable energy, hydrogen stands out as a pivotal solution in this shift. This project aims to fill knowledge gaps related to the transition to supercritical conditions through comprehensive analysis, thereby contributing to the advancement of clean energy technologies. Mechanical and thermal properties suitable for a supercritical metal-water reactor were modelled and simulated in SolidWorks 2022, utilizing plots and mesh results. The reactor was designed to produce hydrogen gas and metal oxide as by-products, with the hydrogen gas being released through a pressure relief valve. The reactor cylinder, made of Ti-6AL-4V, was found suitable for operation at a constant pressure of 25 MPa and a temperature of 380°C. The reactor wall was observed to buckle at pressures exceeding 27 MPa and temperatures above 144,000°C, which are beyond the design conditions. The elastic limit of the cylinder was determined to be 868 MPa, and its ultimate tensile strength was 1,258 MPa, with fracture occurring at 620 MPa. The average damage percentage was calculated to be 0.001%, and the total lifecycle was estimated at 10,000,000 cycles. The integrity of the reactor designed for supercritical states was found to be structurally sound. Detailed insights into the effects of pressure and temperature on the selected material were analysed, enhancing understanding of the reactor's performance under various conditions.

Abstract: Solid polymer electrolyte (SPE) produces hydrogen and oxygen from pure water uses electrochemical reaction, and this process is believed to be the most promising and efficient way to produce hydrogen. For application and simulation, the electrical model of SPE is absolutely required, we intend to develop an electrical model. Where the model has been constructed based on the structure and characteristics of SPE. The electrical model of SPE battery like that consists of a voltage and resistance, that fulfil the equation v=1.936+ 0.0183I-0.013T, to ensure that this model is close to the character of the SPE, we conducted an experiment to validate it, based on the correlation analysis method we obtained those results of the experiment and results of calculation of the model have a correlation is > 0.9988, this meaning that the model is valid.

Abstract: Fossil fuels dependencies need to be stopped to safeguard the earth from further damage. This study focuses on the production of hydrogen (H₂) gas using waste aluminum (Al) cans. Al waste cans were fed into disintegrator to produce fine powder. The hydrolysis performance of disintegrated powdered Al cans were compared with the commercial Al powder. The effect of different reaction temperatures (25 - 100°C); type of alkalis (NaOH, KOH and Ba (OH)₂); and type of water sources (tap, deionized, ultrapure and distilled) for the hydrolysis process were analyzed. The Al powders were also characterized using different techniques to understand its behavior. It was found that powdered Al waste cans produced more H₂ compared to commercial Al reported in the literature. The higher the reaction temperature, the higher the rate of H₂ production. Deionized water maximizes the production of H₂ compared to other types of water. Ba (OH)₂ was found to be an unproductive alkaline for H₂ production using powdered Al waste cans. The successful hydrolysis of powdered Al waste can in alkaline condition in this research has demonstrated as a cost-effective, clean and green alternative hydrogen production method.

Abstract: Titanium dioxide, as a promising photocatalytic material, has been widely used in the fields of environmental pollution control and photocatalytic water splitting to generate hydrogen. In this paper, graphene and N-doping TiO₂ composite film (GR/N-TiO₂) electrode had been grown on titanium foil by one-step anodization, which was simple, time-saving and low cost. The electrode surface was lotusroot-like nanoclusters structure, which had a large specific surface area. The electrode exhibited an excellent optical absorption from ultraviolet to near infrared (200-2500 nm). This was due to the synergistic effects of graphene and N element, and the presence of oxygen vacancy defects. The results showed that the electrode had good electrochemical performances under simulated sunlight, its photocurrent density was about 0.7 mA/cm², the light conversion efficiency was 0.35 %, and the hydrogen production rate was 34 μmol h^-1cm^-2. Thus, the prepared GR/N-TiO₂ film electrode had an excellent hydrogen production activity under sunlight and the potential of converting solar energy into hydrogen energy directly.

Abstract: This study employed statistically based experimental designs to optimize environmental factors for H₂ production from sugarcane bagasse hydrolysate by K. pneumoniae subsp. Pneumonia DSM 30104(T) isolated from wastewater sludge using statistical method. The 12 runs of Plackett-Burman design were used to classify important factors influencing the H₂ production from sugarcane bagasse hydrolysate by K. pneumonia subsp. pneumonia DSM 30104(T). Mutual interaction between the significant factor and their optimal values that brought the maximum H₂ production (mL H₂/L) were further investigated using Box-Behnken design of response surface method. Experimental results indicated that yeast extract, ammonium chloride, potassium chloride, calcium chloride, iron (II) sulfate and total sugar of sugarcane bagasse had an interdependent effect on the maximum H₂ production while only interaction effect between yeast extract and calcium chloride had statistically significant (P≤0.05) influences on the maximum H₂ production. Optimal conditions for the predicted maximal H₂ production were 7.50 g/L yeast extract, 0.50 g/L ammonium chloride, 15.0 g/L potassium chloride, 0.75 g/L calcium chloride, and 10.0 g/L total sugar. At the optimal condition, the maximum H₂ production of 277 mL H₂/L was estimated from Box-Behnken design that more than 9 times compared to Plackett-Burman design. The highest ratio of butyric acid to acetic acid (B/A ratio) of 1.47 was indicated the high performance of H₂ fermentation of sugarcane bagasse hydrolysate by K. pneumoniae subsp. Pneumonia DSM 30104(T) under the optimal condition obtained.

Abstract: Developing a photocatalysis system to generate hydrogen from water is a topic of great interest for fundamental and practical importance. In this study, hydrogen production by a new Z-scheme photocatalysis water splitting system was examined over Rh modified K₄Nb₆O₁₇ nanosheets and Pt/WO₃ photocatalysts for H₂ evolution and O₂ evolution with I^-/IO₃^- electron mediator under UV light irradiation. The H₂ evolution photocatalyst, Rh/K₄Nb₆O₁₇ nanosheets with a slit like framework, was prepared by exfoliation of and proton exchange reaction. Pt/WO₃ prepared by incipient-wetness impregnation method was used as O₂ evolution photocatalyst. The catalysts were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy analysis (XPS), and ultraviolet-visible spectroscopy (UV-vis). These catalysts characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-Vis). In this study, we developed a facile method of preparing K₄Nb₆O₁₇ nanosheets containing Rh nanoparticles. Our results show that I^- concentration and pH of reaction solution significantly influenced the photocatalytic activity. The combination of Rh modified K₄Nb₆O₁₇ nanosheets with Pt/WO₃ achieves a very high photoactivity (H₂: 4240 O₂: 1622 (μmol g^-1 h^-1)).

Abstract: In this study, computational fluid dynamics (CFD) simulation was used to predict the performance of photoelectrocatalytic (PEC) reactors with surface reactions. PEC process is a promising and sustainable method that is capable for simultaneous organic degradation and hydrogen production. However, the overall PEC process efficiency is still unsatisfactory and not ready for scale-up application. Preliminary study using CFD model can help to reduce development time, money and effort in experimental work while providing comprehensive analysis and optimum PEC reactor design prior to its real physical fabrication. CFD model integrates irradiance distribution, hydrodynamics, species mass transport and chemical reaction kinetics within the reactor. The performance of PEC reactor for organic degradation depends on reactor configurations and hydrodynamic conditions. Thus, the main aim of this study was to optimize different PEC reactor designs using CFD modelling by varying the reactor configurations and hydrodynamic flow conditions for improved efficiency in degrading the sample organic pollutant of formic acid. The CFD modelling showed higher formic acid degradation efficiency for the simulated convex surface photoreactor than the flat surface photoreactor due to the former possess the ability to concentrate the absorbed light onto the photoanode surface. Besides, the CFD modelling showed that the formic acid degradation rate increased with decreasing inlet fluid flow velocity. This was due to the uniform flow distribution that enables evenly coverage of photoanode surface for subsequent degradation of formic acid in the PEC reactors. Further experimental work is required to validate the CFD simulation to allow better understanding and improvement of the overall efficiency of PEC reactors.

Abstract: As the hydrogen-rich gas produced by autothermal reforming from ethanol is utilized for the power generation via fuel cell, the change in amount of ethanol and water fed into the autothermal reformer has significant effects on the control of electricity generation and autothermal reaction temperature. The change of water and ethanol amounts affecting on the autothermal reformer temperature control system was studied in this work. An internal model control (IMC) method was designed to control the adiabatic reaction temperature of autothermal reformer by manipulating the input air flow rate. Theoretical analysis demonstrated that IMC method can realize desired performance to control the autothermal reaction temperature when the feed amounts were changed. The results of autothemal reformer control system with and without the feed temperature controller of the preheater unit were compared to offer the suitable control system.

Abstract: This contribution describes a design of experime ntal reactor for decomposing the process of gasses with different contents of hydrocarbons (CH ₄ , C ₂ H ₄ , C ₂ H ₆ , C ₃ H ₆ , C ₃ H ₈ ) . It shows pyrolysis process as a possible source for synthesis gas production . The mathematical modeling ( Ansys Fluent) was used to predict maximal temperature and velocity in three designs and the best result was chosen for manufacturing. Optimal dimensions and material s were chos en basing on the analysis. The ch emical analysis is a second step of research and it is not used in this article .