Advances in Renewable Hydrogen and Other Sustainable Energy Carriers

The share of renewable energies in the energy mix is gradually increasing. This transition brings many challenges in the management of electricity grids, especially because of the fluctuating and intermittent nature of renewable energies. Therefore, hydrogen represents one of the keystones for the sustainable exploitation of our energy resources. Hydrogen allows storing in the long term not consumed but available electricity, and hydrogen is a ‘fuel’ for mobile, nomadic and remote site applications. Once produced and awaiting consumption, the hydrogen must be stored in optimal conditions of safety and efficiency with regard to the application and its location. The most mature solution to date is the storage under the compressed form, which consists in keeping the hydrogen gas in a container at increasing pressures in order to increase the energy density; cryogenic storage is now well controlled but generally reserved for very specific applications for reasons inherent to the technology and because of significant costs; and finally the so-called ‘solid storage’, to which the scientific community has been showing a marked interest for several decades in the hope of identifying a lasting solution likely to replace advantageously other solutions. In this paper, these storage media are introduced by evoking their technological characteristics and their fields of application often justified by inherent limitations of the technology. We will also discuss the challenges still posed by these storage solutions today by linking them with the research work carried out in the Department of Applied Mechanics in FEMTO ST Institute.

This study is deducted to the treatment of wastewater from the organic pollutants and hydrogen production using a photocatalyst composed of Fe2O3 and ZrO2. The structural and photophysical properties of the catalysts have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) and UV–Vis diffuse reflectance spectrometry. The photocatalyst acquired p type conductivity, due to oxygen insertion in the layered lattice with an activation energy of 0.15 eV. The flat band potential (Efb, −0.44 VSCE), close to the photocurrent onset potential (−0.2 VSCE). A total degradation of Methyl orange is achieved within 90 min under sunlight irradiation. The total degradation of phenol is also achieved in less than 120 min. Based on the energy band positions, the detailed reaction mechanism has been discussed. The position of the conduction band in the energy diagram shows the possibility of H2 production under visible light.

In this work, we study the electrochemical performance of anode supported solid oxide fuel cells (SOFCs) based on perovskite-type materials: BaIn0.3Ti0.7O2.85 (BIT07) as an electrolyte, BIT07-Ni as a cermet anode and Pr2NiO4+δ as a cathode. Anode/electrolyte assemblies have been prepared by tape casting and co-firing and the cathode has been deposited by screen-printing. The performance of BIT07-Ni/BIT07/Pr2NiO4+δ cells has been determined between 600 and 750 °C under humidified (3% H2O) hydrogen as fuel and air as oxidant. The presence of an interfacial layer of gadolinia doped ceria (GDC) is also tested. Impedance Spectroscopy (EIS) measurements have also been carried out and allowed to differentiate between the series and polarization resistances. The power density obtained from the cell with GDC was 119.21 mW/cm2 at 700 °C, compared with 28.1 mW/cm2 for the cell without GDC thin layer. These results confirmed that the presence of a dense thin layer of GDC at the interface electrolyte/cathode is a very promising method for intermediate temperature SOFCs (IT-SOFCs) to increase the performance.

We reported for the first time a facile method for the preparation of the spinel CuCo2O4 at 140 °C by using sulfates of copper and cobalt in KOH. The compound crystallizes in a cubic system (SG: F d $$ \bar{3} $$ 3 ¯ m) with a lattice constant of 8.0590 Å. The material was characterized by physical and photo-electrochemical techniques. The X-ray diffraction (XRD) pattern confirms the single phase with a high purity. The UV–Visible spectroscopy of the black product revealed a direct optical transition of 1.38 eV. The capacitance-potential (C−2-E) displays a negative slope and a flat band potential (+0.28 VSCE) characteristic of p-type semiconductor behavior. Further, the Nyquist plot shows a semicircle followed by straight line at low frequencies, indicating a diffusion process. To show effectively the photocatalytic performance, we tested our product in the hydrogen production upon visible light irradiation. H2 evolution rate of 7 µmol h−1 mg−1 and a quantum efficiency of 1.1% were obtained upon visible light illumination.

A new spinel solid solution system of Ni1−xFexAl2O4 (0.0 ≤ x ≤ 0.5) was synthesized through sol-gel method. The effect of Fe doping on the electrocatalytic properties of nickel aluminate was investigated. The synthesized powders were characterized by means of X-ray diffraction, scanning electron microscopy and electrochemical measurements. From the preceding analysis, it can be shown that compounds show a single spinel phase in the temperature range of 650–1000 °C and the solubility of iron in the NiAl2O4 structure was limited to x ≤ 0.5. The electrochemical measurements indicate that the catalytic activity is strongly influenced by iron doping. The highest electrode performance is achieved with Ni0.7Fe0.3Al2O4 (i = 86.84 mA/cm2) which is ~27 times greater than that of NiAl2O4 (i = 3.22 mA/cm2) at E = +0.8 V. After one hundred cycles, the stability of the doped electrode with 30% of iron is much better than that of the undoped electrode. These results indicate clearly that Ni0.7Fe0.3Al2O4 electrode has promising potential for cost-effective potential generation.

The development of a safe and efficient storage method is a key to achieving hydrogen economy. The zeolites are crystalline and porous aluminosilicate. They are potential candidates for hydrogen storage. These materials are well known for their electrostatic fields due to the differences in electronegativity between the atoms of aluminum, silicon, oxygen and compensation cations. In addition to temperature and pressure, the adsorption of hydrogen on zeolites depends also on the crystal lattice topology and compensating cations. Several studies have illustrated the effect of exchange on the adsorption capacity of these materials. These properties promote the zeolite’s surface energy change leading to an increase in the hydrogen’s uptake capacity. Charge compensation ions in the zeolite’s framework are considered as adsorption centers and the structure’s oxygen bridges as minor adsorption sites. Indeed, the gained mass per unit of area reveals the effect of the ion’s exchange in terms of cation’s size and charge.

Lantanium and Cerium supported Nickel catalysts with Ni-loading close to 15 %wt were synthesized using sol-gel methods in order to design efficient catalysts for the dry reforming of methane to produce syngas (H2 + CO). The catalytic test was performed after calcining the as-prepared samples at 700 °C and subsequent in situ reduction was performed under hydrogen flow at 600 °C. The resulting catalysts were characterized by X-ray diffraction (XRD), Temperature Programmed Reduction (TPR), transmission electron microscopy (TEM) and N2 adsorption-desorption isotherm measurements. The investigation of the catalytic performances of Ni–CeO2 and Ni–La2O3 catalysts prepared by sol gel method (SG), for a duration of 12 h, under a reaction CH4/CO2 shows that, for the same synthesis method, the efficiency varies with according to the support nature. Indeed, conversions and yields are higher in the presence of the lanthanum than with the cerium support (XCO2 = 18% and YCo = 15% for Ni–La compared of XCO2 = 8% and YCo = 6% for Ni–Ce. Comparing the catalysts stability, we can notice that it is 100% (no deactivation) in the presence of Ni–La2O3 catalyst compared to Ni–CeO2, which showed a high deactivation (78% after 12 h of reaction). This difference in stability is probably related to the perovskite structure and to the strong interactions between the active phase and the support, reinforced by the basicity of lanthanum support which inhibits carbon deposition during the CH4/CO2 reaction.

The influence of the addition of hydrogen on the formation of soot in an ethylene-gas/air mixture of a counter-current laminar diffusion flame in the flameless regime and at atmospheric pressure has been studied. A detailed gas phase reaction mechanism, including aromatic chemistry up to four cycles and complex thermal and transport properties, was used. The soot is modeled by the moments method. The interactions between soot and gas phase chemistry have been taken into account. Losses by thermal radiation (from CO2, CO, H2O from CH4 and soot) modeled by a thin body. Adding hydrogen to the fuel eliminates the formation of soot. The calculations further suggest that the effect of the addition of hydrogen on soot formation is due to the absence of the concentration of hydrogen atoms in the surface growth regions of soot (stagnation plane) and at a higher concentration of molecular hydrogen in the flame zone. It also reduces the concentrations of C3H3, C6H6 as well as PAHs (for example, pyrene) which all suppress the process of soot formation.

To reduce combustion harmful emissions such as CH4, CO2 and NO, low calorific renewable biofuels are found to be the best candidate. Combustion of biofuels gives a weak unstable flame which can be enhanced by hydrogen addition. The latter can also be obtained from a renewable source like syngas. In this context the mixture biogas-syngas is studied to overcome combustion emissions issues. A two-dimensional numerical procedure has been used to investigate the opposed jet turbulent flame structure of biogas-syngas mixture. The standard k-ε model is adopted for turbulence modeling and the Steady Laminar Flammelettes Model (SLFM) to handle turbulent combustion. The combustion kinetics is modeled by the detailed Glarborg’s N-mechanism. Equimolar biogas-syngas mixture is considered, namely: biogas 0.25CH4 + 0.25CO2 and syngas 0.25H2 + 0.25CO. Injection velocity is equal for both jets and it is varied from 3 to 12 m/sec. It has been noticed that when injection velocity increases, the flow residence time and non-equilibrium effects are enhanced. This improves incomplete reaction species production and reduces final combustion products volume, temperature and NO species emission. As a summary, the NO emission can be avoided by using important injection velocities.

In the present study, the effect of composition, pressure and inlet temperature on NO production in non-premixed MILD (Moderate or Intense Low-oxygen Dilution) combustion of biogas-syngas mixture is evaluated numerically. Several pressures, compositions and inlet temperatures are considered. Results showed that NO formation increase highly with increasing pressure and oxidizer injection temperature (Tox). It is found that production of NO is more sensitive to increasing Tox than decreasing pressure. Moreover, effect of pressure is reduced as volume of hydrogen decreases in mixture. Also, increase of maximum NO mole fraction, as a function of injection temperature is important for the B50S25 mixture. Furthermore, effect of pressure and injection temperature on different NO production routes (thermal, prompt, N2O and NO2) were evaluated. It is noticed that at low pressure, NO is mainly produced by prompt path, whereas NO2 mechanism prevails when pressure is increased. When oxidizer temperature increases, most important mechanism that produces NO is prompt one followed by thermal route and finally NO2 path. It is noticed that N2O production route is trivial for all values of pressure and Tox. The reaction path diagram was presented to show the formation routes of NO for different pressures.

Energy conversion through combustion is one of main energy production processes. The research related to combustion has progressed enormously, leading to an improvement in energy performance in industrial combustion systems. Relative to strong growth in global energy demand, gradual depletion of fossil resources is reported. The latter generates an improvement in combustion processes and makes energy optimization a major challenge for researchers. On the other hand, the combustion emissions to the atmosphere are considered as one of main environmental and climate change concerns. This work analyzes the non-premixed flameless combustion of CH4-syngaz mixture in opposed jet configuration. Kinetics of combustion is described by Grimech 3.0 mechanism, calculations are achieved by Chemkin code. Several ratio values were considered, fuel injection temperature is T = 300 K, that of oxidant is 1200 K with a constant pressure equals to one atmosphere. It has been found that increasing H2/CO ratio does not affect combustion temperature and consequently NO emission. Furthermore, a large reduction in NO2 has been depicted. The replacement of N2 by CO2 in the oxidizer has a significant impact on the thermal field and species.

Variability and intermittency are some of the features renewable energies (REs). Due to their intermittent nature, it is very difficult to predict energy production, which requires either additional supply plants or new storage and control technologies. This work presents the sustainable development of a RE production chain. Reinforcement and optimization of the chain are also considered. At the same time, an energy management strategy (EMS) for a standalone photovoltaic (PV) and wind system integrated with fuel cell is presented. The EMS is aimed to coordinate the power flow of the system components while satisfying load demand and other constraints. System optimization and EMS are combined such that it is unusual to discuss them individually from a system-level design perspective. Therefore, optimization by a Chaotic Bacterial Foraging Optimization (CBFO) algorithm based on multi-cross learning (M-CL) mechanism is proposed to ensure an EMS of the system. The performance of the proposed system is validated by simulation and obtained results prove the efficacy and the feasibility of the proposed approach.

The hybrid organic-inorganic halide perovskite solar cells based on CH3NH3PbI3 have attracted enormous attention in the last few years due to their rapid improvement and high certified efficiencies over 20%. In this paper, the tetragonal structure of CH3NH3PbI3 hydrides was investigated by first-principles calculations based on density functional theory (DFT) with the generalized gradient approximation (GGA). The elastic constants for the tetragonal CH3NH3PbI3 hydride are successfully obtained from the stress-strain relationship calculations. The obtained equilibrium lattice parameters and elastic constant (Cij) are in good agreement with other theoretical values and experimental data available in the literature. The shear modulus (G), bulk modulus (B), Young’s modulus (E), Poisson’s ratio (ν) and the ratios (B/G) are also determined. The calculated bulk modulus and the ductility factor (B/G) shows that the CH3NH3PbI3 hydrides which indicates that this material is ductile behaviour. Also, the universal Poisson’s ratio (ν) is higher than the critical value.

Today, alternative and sustainable solutions are proposed to replace fossil fuels. Hydrogen production from renewable energy sources has gained special attention in recent years, especially biohydrogen production from biomass resources which is accepted as a sustainable ecofriendly approach, it is a colorless gas, tasteless, odorless, light and non-toxic. When this gas is used as fuel, air pollution will not be produced, only water is produced and considered as end-product. This work aims to develop a microbial biohydrogen electrosynthesis using Enterobacter cloacae strain bacteria isolated from Beni-Messous wastewater. Very little informations are available on the hydrogen production using E. cloacae, which is a gram negative, motile, facultative anaerobe. The present work deals an electrochemical study from linear and cyclic voltammetry tests examining the hydrogen evolution reduction in biocathode in order to optimize the biohydrogen production. The acetate fermentation, the proton H+ accumulation and reduction had allowed an increase in current density from −19 to −96.6 mA/m2 with the E. cloacae strain.

The spinel type compounds represent a new family of photocatalysts that can be used as photoelectrodes capable to produce hydrogen under visible light. In the current study, the CuFe2O4 spinel, which is prepared by the sole-gel method, is investigated as a possible candidate, and the structure, opto-electronic, electrochemical and photoactive properties are characterized. CuFe2O4 exhibits a p-type semiconductor; the conduction mechanism is assigned to the typical small polaron hopping of semiconductor conduction band ‘d’. Determining the potential of the flat strip electrochemically has established an energy digraph to predict the duality between the physico-chemical properties and photocatalytic activity. The production of hydrogen under visible light was selected to evaluate the photoactivity. Sensors holes: Na2S, Na2SO3 and oxalic acid were studied. The best performance was obtained by Na2Sin basic medium.

The structural stability of the SrAlH3 has been investigated using the density-functional theory with the generalized-gradient approximation, pseudo-potential and plane wave method, for hydrogen storage application. Indeed, we have predicted structures for hypothetical compounds SrAlH3 by considering 24 different guess structures possible and have been attained through energy minimization and force relaxation, for the above guess structures. The most stable arrangement being the tetragonal PCF3-type (tP40) structure, which contains distorted octahedral. At higher pressure this phase transform into the orthorhombic GdFeO3-type (oP20) at 31.8 GPa. We have fitted the total energy as function of cell volume using the so-called universal equation of state and we have found that SrAlH3 have a bulk modulus B equal to 37.11 and 44.88 Gpa for P42/nmc (space group n° 137) and Pnma (space group 62) respectively. The formation energy, the electronic density of states, charge density, charge transfer, electron-localization function and Born effective charge are investigated and discussed.

This work presents a numerical study of hydrogen production via steam methane reforming (SMR) process in a monolithic reactor. Two parallel coated catalytic layers of order of micrometers consist of Nickel (Ni) supported on α- Al2O3 and structured in a rectangular channel are used to achieve more methane conversion and high levels of compactness. In order to find the influence of the copper foam, two configurations were numerically studied and compared. In the first case, the feed was introduced directly without using the metal foam. While in the second configuration, the reactor was fitted with copper foam. Indeed, SMR reaction is a high endothermic process requiring a great energy to achieve the activation condition. Although the Ni catalyst reduces this energy, it is recommended to increase the thermal efficiency improvement, thus the methane conversion, the hydrogen yield, and as a result pollution effects are minimized. It has been shown that using copper metal foam promotes the heat conduction, which is very small in gas phases. In addition, it has been found that the use of the copper foam enhances the hydrogen yield by 6.42%, and the catalyst length can be reduced by 9.67% while maintaining the same results. Therefore, the metal foam can positively impact the SMR reaction and reduces the process costs.

We investigated the technical feasibility of photochemical hydrogen release based on CuFe2O4 powder dispersion in an aqueous electrolyte containing a reducing agent ( $${\text{S}}_{2} {{\text{O}}_{3}}^{ - 2}$$ S 2 O 3 - 2 ). The oxide combines an average resistance to corrosion and an optimum inter-referred band Eg of 1.67 eV. The intercalation of a small amount of oxygen should be accompanied by partial oxidation of Cu+ to Cu2+ involving a p-type semi-conductivity. The oxidation S2− inhibits the photo-corrosion, and the evolution of H2 increases in parallel with the formation of polysulfides. Most of H2 is produced when p-CuFe2O4 is connected to n-ZnO formed in situ. The release of H2 is mainly on CuFe2O4, whereas, the oxidation of S2− takes place on the surface of ZnO and the hetero-system CuFe2O4/ZnO is optimized with respect to certain physical parameters. The photoelectrochemical production of H2 is a multi-step process whose decisive step is the arrival of electrons at the interface due to their low mobility. Remarkable performance with a rate of 6.74 (μmol g−1 min−1) cm3 h−1 hydrogen evolution in 0.1 M $${\text{S}}_{2} {{\text{O}}_{3}}^{ - 2}$$ S 2 O 3 - 2 (pH 13) is recorded.

In this paper, a numerical study has been conducted for analyzing the autothermal steam methane reforming reactor activated with a dual-bed catalyst (Pt–Ni). The fluid passes through two successive beds in which the first one is devoted for the oxidation reaction and consists of platinum (Pt) catalyst based on the Al2O3 support, while the reforming reaction was activated with the following bed that consists of nickel (Ni) catalyst based on the Al2O3 support. This configuration was validated, evaluated and the evolution of the different species are illustrated along the reactor length. The reactor was considered as a high thermally performed and well intensified process because the thermal source supplies directly the reforming reaction compared to the externally heated steam methane reforming. The results have shown good hydrogen yield with a generated hydrogen molar fraction of 22.16% as well as the reported conventional autothermal reformer (Wang et al. in Fuel Process Technol 91:723–728, 2010 [1]). Moreover, this dual-bed configuration shows more smoothly temperature profile, and less temperature gradient which can enhance the reactor stability. On the other hand, the temperature peak was about 1438.17 °C which is nearly the same in the conventional reformer (Wang et al. in Fuel Process Technol 91:723–728, 2010 [1]).

In this paper we analyzed an autothermal reformer for the hydrogen production from methane and vapor. The endothermic reforming reaction was heated with the exothermic reaction of methane combustion inside a rectangular reactor. The reforming reaction was activated with nickel (Ni) catalyst layer that coated on one wall of the reactor, while the second wall was coated with platinum (Pt) catalyst in order to activate the combustion reaction. The quantity of the catalysts used for each reaction has an important effect on the process. A low quantity of the catalysts can decrease the hydrogen yield, on the other hand, additional quantity can increase reactor conception costs. So that, the optimization of the process to find out an adequate quantity of catalysts is required to improve the process [1]. The Ni catalyst thickness was varied from 1 × 10−4 m to 4 × 10−4 m while the variation of the Pt catalyst was between 5 × 10−6 m and 4 × 10−5 m. The results showed that the hydrogen yield achieved an optimum value of 36.295% was obtained when the catalyst was operated under a catalyst thickness of 2 × 10−4 m for the Ni catalyst, while, the thickness of the Pt catalyst was of 2 × 10−5 m. the maximum temperature.

In this article, we proposed a more reliable architecture composed of five fuel cell modules (FC), a storage system composed of battery and supercapacitor was also proposed to support the operation of the fuel cell. The main objective of this work is to study the feasibility of using the global system for small marine applications. In this paper, the global system was modeled and then simulated using Matlab/Simulink. The fuel cell is used as the main power source; each fuel cell is connected with a DC bus via a DC–DC boost converter. The Energy Storage System (HESS) is controlled as a fast-bidirectional auxiliary power source, it contains a battery and supercapacitors and each source is connected to the DC bus via a bidirectional buck-boost DC–DC converter (BBDCC). In order to optimize the HESS, the supercapacitors and the batteries are designed to allow high-efficiency operation and minimal weight. The entire system’s energy management algorithm (PMA) is developed to satisfy the energy demand of the boat. Finally, simulation tests are presented in Matlab/Simulink and discussed, where the effectiveness of the proposed system with its control is confirmed.

The cogeneration system, studied in this paper, optimize the use of electricity and heat in a one source production system. The electricity and heat load profiles were determined for a subdivision of 50 single-family homes. It was noted that, annually the electricity demand represents 68% of total energy demand and the rest (32%) is a heat demand. To ensure the supply of energy, a photovoltaic generator coupled with a set of fuel cells was considered. Fuel cells are powered by hydrogen supplied by electrolyzers and stored at high pressure in containers. The system can produce electricity that will be converted for domestic use and heat that will be recovered for use as warm water or homes heating when necessary. The whole system is completely autonomous and does not require the grid in any way. The main issue is therefore the intelligent management of the whole through appropriate algorithms whose main objective is to provide energy without any interruption.

In this paper, we present a bibliographical review of tri-generation systems using renewable fuel. These systems are used to produce cold, heat and power from mainly one fuel source. This mode of operation increases overall efficiency and allows better use of the input fuel. Most tri-generation systems use a fuel cell for its reliability and performance. Furthermore, fuel cells produce heat and electricity at a very high efficiency compared to classical systems. A part of produced heat is recovered to produce cold by an absorption cycle when necessary. The fuel cell can be fed by various fuels, including natural gas, hydrogen produced from renewable or biomass gasification. The overall efficiency depends on the configuration and management of the entire system. The optimal sizing of tri-generation systems is a complicated task. It generally requires two optimization algorithms, one to optimize power flows within the system and the other to optimize the size of the elements. The optimal sizing of tri-generation systems requires two optimization algorithms, one to optimize power flows within the system and the other to optimize the size of each element of the system. Between 75 and 95%, efficiency can be attained depending on the choice of production system and energy management strategy.

According to the directive of the European Union on the incorporation of biodiesel in fuels by 2020, the aim of this study is to contribute to understanding the feasibility of using ester methyl of waste cooking oil (EMWC Oil) in diesel engine. However, biodiesel is a renewable environmental friendly fuel consisting of esters methyl of vegetable oil, generally produced by transesterification reaction of oils seeds and animal fats. In this study, biodiesel synthesis by transesterification of waste cooking oil has been realized. The biodiesel is produced via transesterification reaction using methanol (6:1 molar ration), 0.5% of sodium hydroxide at 55 °C for 60 min of duration and Stirring speed of 200 rpm. The application of design experiment methodology for response surface has allowed us to determine the optimum factors influencing on the transesterification reaction efficiency. The synthesized biodiesel has been subject to several characterizations in order to evaluate its quality by comparing its different physicochemical properties with those described in international norms.

Hydrogen is clean energy career that can be produced through renewable energies. Solar plant with parabolic trough concentrators systems is a one of the most promising renewable energies sources for producing energy. This technology is tightly related to the solar insolation levels. Algeria has a potential of Direct Normal Insolation (DNI) that exceeds 2000 kWh/m2/year with an average daily sunlight duration that exceeds 10 h. Thus are the key features for the development of Solar plant. This paper deals with numerical simulations of a small-scale electrolytic hydrogen production using solar plant with parabolic trough concentrators via an Organic Rankine Cycle. The city of Ghardaïa, located in south of Algeria was selected as a study site. The results have demonstrated among the three organic working fluids (Benzene, Toluene, R-123) selected, benzene is the fluid offering the best efficiency. Moreover, the amounts of hydrogen produced are closely related to the organic fluid used as well as the intensity of the solar radiation.

The object of the present work is the thermodynamic study of the proton ceramic fuel cell; particular attention is given to evaluate and maximize the generated power density by a single cell of Protonic Ceramic Fuel Cell (PCFC). In this work, the real potential is given by the difference between the Nernst potential and the reel polarizations generated during the PCFC operation. The activation polarization of the chemical reactions in the anode and the cathode, the losses due to the species concentration in both electrodes (anode and cathode) and the ohmic losses produced by the Joule’s effect in the electrolyte and both electrodes (anode and cathode) are considered as the reel polarizations. The obtained results show that the PCFC power density is proportional to the variations of the operating temperature and the oxygen concentration in the oxidizer; conversely, it is inversely proportional to the evolutions of the fuel humidification and the thicknesses of the electrolyte.

Proton Exchange Membrane Fuel cells (PEMFC) are used in many engineering applications as a power source. The device has a mathematical model by which the output voltage-current (V-I) characteristics can be estimated at various operating conditions. However, this model comprises several nonlinear coupled parameters, and that makes the identification problem as challenging task. Owing to that, some advanced techniques been employed to extract the optimal constants of a PEMFC including meta-heuristic optimization algorithms. At this point, this paper deals with a novel swarm-intelligence optimization method named Whale Optimization Algorithm for the purpose of extracting the exact parameters of the PEMFC. This investigation is conducted to examine the effectiveness of the method in providing better results compared to other methods presented in the literature. A commercial PEMFC from Heliocentris with rated power = 40 W is employed to conduct a series of experiments in the laboratory. Moreover, to confirm the effectuality of the method, the results are compared with Particle-Swarm-Optimization (PSO) algorithm. The proposed method showed a significant enhancement in terms of accuracy and convergence speed compared to PSO, where, the error between the predicted and real data was negligibly small (Mean Absolute Error = 0.0726 V).

The current study assesses, through a thermodynamic analysis, how well six alternative fuels, namely methanol, ethanol, LPG, biodiesel and hydrogen perform compared to LNG fuel in an HCCI engine. In addition to traditional energetic analysis, the second law of thermodynamics, through the concept of exergy, is used to provide detailed information on the thermodynamic processes during an engine cycle. In particular, the sources and magnitudes of the energy wasted in the system are evaluated and methods to reduce them can be afforded. Results indicate that the engine thermodynamic performances with the type of fuel used. The highest engine performance values are obtained using biodiesel as fuel, followed, in order, by ethanol, LPG, methanol, LNG and hydrogen. Furthermore, it is observed that the use of hydrogen in HCCI engine leads to increased exhaust gas temperature which. Thus, its overall performance can be effectively enhanced by using heat recovery techniques.

In this study, a mathematical model is used in order to analyse the influence of some usual engine parameters such as compression ratio, turbocharger compressor pressure ratio, equivalence ratio, and engine speed on the performances of a Diesel-hydrogen dual fuel marine engine. The model takes into account the gas composition resulting from the combustion process and the specific heat temperature dependency of the working fluid. The analysis is based on both the first and second laws of thermodynamics using the concept of exergy analysis. Results showed that, overall, the variation in the engine operating parameters (rc, rp, N and ϕ) affects considerably the engine performance. Furthermore, an exergy loss mapping of the system indicates that most of exergy losses (88.2%) occur in the engine due to due to the irreversible nature of the mixing and combustion processes. The remaining components (turbo-compressor, intercooler, mixer, catalytic converter and turbine) are responsible of only 11.2% of the total exergy loss of the system.

In this work, we study the effect of bluff body shape on the proprieties of Hydrogen-air flame propagating in a narrow channel, specially its stabilization. The study is conducted with a 3D CFD numerical simulation with detailed reactional mechanism. In this work, the Finite Volume Method is applied. In other hand, the k-ε turbulence model was adopted and no artificial flame anchoring boundary conditions was used. The results show dependence between flame structure and bluff body shape. This impact is particularly clear on its thermal properties. Indeed, it appears that the flame has a stretched appearance. This stretch increases particularly at the flame front. However, the heat losses determine the flame anchoring location. In other hand, results analyze shows a dependence between flame location and vortices dilatation of the turbulent flow in the narrow channel with bluff-bodies. The stability of the flame is increased when a triangular or semicircular bluff-body is applied.

Due to the increasing air pollution and growing demand for green energy, the most of research is focused on renewable and sustainable energy. In this work, the PEM fuel cell is proposed as a solution to reduce the impact of the internal combustion engines on air pollution. In this paper a PEM fuel cell, battery and supercapacitor energy conversion system is proposed to ensure the energy demand for an electric vehicle is achived. The storage system consisting of a battery and supercapacitor offers good performance in terms of autonomy and power availability. In this paper, an energy management of the PEM fuel cell electric vehicle has been first simulated in Matlab/Simulink environment and the results are discussed. Second, a Realtime experimental set up is used to test the performance of the proposed PEM fuel cell electric vehicle system. Experimental results have shown that the proposed system is able to satisfy the energy demand of the electric vehicle.

It is well known that an adequate choice of operating parameters can result in a high power density and an extension life of a proton exchange membrane fuel cell PEMFC. The aim of this study is to optimize the operating parameters at the inlet of a PEMFC. At first, objective functions are defined to study the problem, according to the desired objective. We have proposed three case studies of single-objective problems. These latter have been solved by the Particle Swarm Optimization algorithm PSO. In a second step, the objective is to simultaneously obtain the highest possible power density and to minimize the dispersion of the current density along the flow channel from its average value. The Non-dominated Sorting Genetic Algorithm NSGA-II is adopted for solving the multi-objective problem. The multi-objective approach allows finding several compromise solutions that allow the user to make the appropriate choice depending on the intended application. These solutions are presented by the Pareto front, containing the set of optimal solutions.

The aim of this paper focuses on optimal sizing of Energy Storage System (ESS) based on Fuel cell using different battery technologies for Fuel Cell Electric Vehicles (FCEV) applications. The main objective consists to optimize ESS sizes, cost with a longer lifecycle for a Fuel Cell Electric Vehicle with 650 km driving cycle range. In this way, we study the influence of battery technologies which is considered as a secondary source on the storage system characteristics. The obtained results show that considerable gains have been achieved in terms of weight, volume and cost using Ultra High Power (UHP) technology comparatively with high power and high energy technologies. Otherwise, an experimental validation is carried out to complement the simulation results via a 1 kW test bench with Hardware In the Loop approach. As expected, UHP technology confirms its capabilities of decreasing the applied stress on the fuel cell and consequently reduces the hydrogen consumption.

In this study, Microbial electrolysis cells (MECs) are used for the treatment of actual paper and pulp industry wastewater and production of biohydrogen, for the evaluation of economical and low-cost cathodes. Nickel, Nickel-Cobalt and Nickel-Cobalt-Phosphate electroplating on SS and Cu rod are explored as-fabricated cathode catalysts in MECs for the estimation of their electrocatalytic activity in terms of energy recovery and treatment efficiency using paper-pulp industry real wastewater. Developed cathodes are explore in MECs in a controlled temperature of 30 ± 2 °C, under applied voltage of 0.6 V at neutral pH with paper-pulp industry wastewater and activated sludge as inoculum. Simultaneously treatment of paper pulp industry wastewater with hydrogen production rates (1.1–3.82 m3/m3-d) and 54–65% of initial COD removal. Obtained results suggest that fabricated cathodes have potential to become alternative to Pt. for the treatment of real industrial wastewater using MECs. It also indicates that the hydrogen production and MECs performance greatly depends on the composition of wastewater and inoculum. MECs performances ware evaluated in terms of hydrogen production rate, columbic efficiencies, overall energy efficiency, and volumetric current density.

The proton exchange membrane fuel cell (PEMFC), an electrochemical device for converting the chemical energy into electrical energy and heat, is currently considered one of the most promising systems for development of renewable and non-polluting energies. Water management in the PEMFC remains one of the major obstacles to be solved for the commercialization of this technique on a large scale. Flooding and drying are the two main degradation mechanisms that occur when water management is inadequate, and have a direct impact on the resistance and the fuel cell (FC) active area. Therefore, since the impact of these faults is known, the output fuel cell voltage is also predictable. This paper presents an improved fuel cell model that reproduce the output fuel cell voltage behavior in event of water management fault. A future solution is also proposed for fault tolerant system by using a new DC-DC converter with a high gain. Finally, model results are verified using MATLAB Simulink.

Microbial Fuel Cell (MFC) is an electrochemical device that converts polluted organic matter into electricity by using microorganisms as biocatalyst. Indeed, MFC can produce low renewable electric energy but preserve the environment. The aim of this study was to design a MFC-based biosensor using household wastes, in which anaerobes contained in the anolyte, are separated from the catholyte with a cation exchange membrane. This biosensor has been used to analyze biodegradable waste organic matter, where anaerobes act as biocatalyst for their oxidation and the transfer of electrons to the anode. Sodium acetate solution was used as substrate to obtain maximum energy. The MFC-based biosensor system was optimized by discharging it into an external circuit and phosphate solution buffer mixed with sodium chloride solution used as catholyte in the aerobic compartment. The anaerobic compartment was kept at room temperature to promote bacterial growth. It turned out that the MFC’s tension increased with the concentration of sodium acetate. It varied linearly with the substrate concentration, on a semi-logarithmic scale, thus making it possible to determine the minimum and maximum concentration thresholds. In addition, the electrochemical characterization by cyclic voltammetry of the bio-anode, revealed the oxidation current due to the degradation of the organic matter, which varied linearly with the scanning speed, highlighting the adsorption phenomenon on the surface of the porous electrode carbon felt. The MFC with a renewable aerobic bacterial source could therefore be used as a biosensor for on-line detection of pollution, in this case oxidized organic matter.

The increase of both energy demand and pollution makes essential the use of renewable energy. Green electricity production is one of numerous challenges of researches and the target is to obtain an economic clean energy with high performance and no emission of pollutants. Hydrogen fuel cell is an electrochemical process in which chemical energy is transformed into electrical energy. This reaction occurs by using hydrogen. A biological fuel cell is one of numerous types of fuel cell using living organisms to generate electricity. In a microbial fuel cell (MFC) the catalyst is the microorganisms and the most often bacteria. In plant microbial fuel cell (P-MFC), the rhizospheric microorganisms are the catalyst. Plants produce carbohydrates through photosynthesis and feed with rhizodeposits the rhizospheric microorganisms which generate electricity. This paper is a presentation of 2 P-MFC using two different plant species Arundo donax L. and Chlorophytum comosum L in the same experimental conditions. During 43 days we measured the electrical potential produced in Arundo donax-MFC and Chlorophytum comosum-MFC and we compare the 2 P-MFC system to evaluate plant species performances. Results show a different electrical potential for the two plants. The maximum tension registered for Arundo donax L. is +145.2 mV and for Chlorophytum comosum L. is +155.3 mV.

Today, electric vehicle (EV) appears as an evident solution for the future automotive market. The introduction of EV will lead to the reduction of greenhouse gas emissions and decrease the travelling cost. However, electric vehicle is truly an ecological solution only if the production of electricity necessary for its operation is produced from sustainable energy sources. In this paper, an Electric Vehicle Charging Station (EVCS) through sustainable energy sources via a DC micro-grid system has been proposed. The proposed system includes a fuel cell (FC), photovoltaic (PV) panels, storage battery and possibility of a connection to the grid. In this work a low power prototype of a micro-grid based EVCS has been first validated using a numerical simulation under Matlab/Simulink using variable irradiance and number of recharging vehicles. In the second part of this paper, an EVCS prototype has been realized in the laboratory. The tests are realized using an emulator of the PEM fuel cell with the concept of the hardware-in-the-loop (HIL). The objective of this emulation is to evaluate the performances of the whole system without the need for a real fuel cell. The whole system is implemented on the dSPACE 1103 platform and the results of the tests are discussed.

The Double layered hydroxides (LDH) called anionic clays are the most studied laminated materials. The CoAl-LDH and CoFe-LDH hydrotalcite-like compounds were successfully synthesized by co-precipitation method with Co2+/Al3+ = 2 and pH = 12. After calcination under air at 800 °C. The solids were characterized by means of XRD, BET area, N2 adsorption and desorption, TPR-H2, chemical analysis by ICPs. Reforming of methane with carbon dioxide to synthesis gas, which is also referred to as dry reforming of methane represents an industrially relevant process that meets the criteria of green chemistry and of environmental protection: In this respect, CO2 and CH4, both considered as one of the main greenhouse gases responsible for out planet’s global warming phenomenon, are converted to furnish a more useful mixture of gas containing H2 and CO, syngas. After reduction, the catalysts were evaluated in the reforming of methane reaction under continuous flow with CH4/CO2 ratio equal to 1, at atmospheric pressure and a temperature range [500–700 °C]. The catalytic activity was tested in a fixed bed reactor.

Environmental pollution has become a major issue due to the rapid growth of industrial and technological developments that requires a high consumption of fossil energy. A new route of treatment of pollutant molecules bases on the use of non-equilibrium thermodynamic reactive plasmas generated by electrical discharges at atmospheric pressure to neutralize or transform toxic oxides as CO2 [1–6]. This type of non-equilibrium reactive plasma can be used for the decontamination of gaseous effluents and is generally generated by a pulsed discharge which constitutes a chemically very active medium of low energy consumption. Our work will be based on a zero-dimensional model, to study the reduction of COx in the CO2/O2 gas mixture by dielectric barrier discharge of non-equilibrium plasma under typical operating conditions of the discharge. A model allows to calculate the temporal evolutions of chemical characteristics. The influence of certain discharge parameters such as the applied electric voltage, the gas pressure, the capacity of the dielectric, the discharge frequency and the concentration of oxygen in the gaseous mixture on the density variations of CO and CO2 compared to the initial density of CO2 in the gas mixture of the discharge have been analyzed.

The main interest of the Wankel rotary engine is its higher power density as compared to similar conventional engine. However, the unusual geometry of the Wankel engine affects negatively the engine economy and the exhaust emissions. The knowledge of the rotary Wankel engine drawbacks and fuel characteristics can help to choose which fuel can achieve the best performance with that kind of engine. The aim of this paper is to compare the experimental results of the performance of a monorotor Wankel engine fuelled with gasoline, ethanol and then after hydrogen addition to each fuel used, at lean operating condition and full load regime. Testing were carried out under constant engine speed of 3000 rpm, fixed spark timing of 15° BTDC, at lean to ultra lean and full load conditions. The test results have shown that pure ethanol burns more efficiently than gasoline. Moreover, the addition of hydrogen helps to achieve better brake mean effective pressure, thermal efficiency and reduce the fuel consumption for both fuel, however, this improvement is more significant for gasoline engine.

Hybrid sulfur (HyS) cycle or Westinghouse cycle is among the main candidates for full-scale solar hydrogen production. This cycle is one of the most attractive and simplest thermochemical processes, because it comprises only two global reaction steps and has only fluid reactants. The decomposition of sulfuric acid is a vital step in the sulfuric hybrid cycle process for the production of hydrogen from water. For this, the temperature needed for SO3 to be converted into SO2 and O2 is very high. It requires operating temperatures above 800 °C. Thus, SO2 compound resulting from the decomposition reactor is the key compound used to feed the electrolyser where it is oxidized to regenerate H2SO4 and produce H2. This work focused on the sulfuric acid decomposition step in suggested tubular plug flow reactor with possible use of solar energy. A parametric study on the effects of temperature and pressure on the thermodynamics conversion of SO3 to SO2 was investigated. The theoretical sulfur trioxide conversion calculation was applied where a plug flow reactor model was assumed.

10% NiO/γ–Al2O3 was synthesized by wet impregnating γ–Al2O3 with Ni(NO3)2, 6H2O solution. After evaporation, the sample was calcined in air at 450 °C. The insulator γ–Al2O3 was used as support to offer a large distribution of NiO, leading to a higher specific surface area, an enhanced photosensibility. The sensitizer NiO was characterized by physical and photoelectrochemical techniques. The XRD pattern exhibits the peaks of both γ–Al2O3 and NiO. The particle size of NiO (18 nm) was calculated from the full width at half maximum. The optical gap was found at 1.51 eV and the transition is directly permitted. The capacitance measurement indicates n-type semiconductor and the potential of conduction band (−0.35 VSCE), is more cathodic than the H2O/H2 level (∼−0.3 VSCE) at pH ∼13. Such condition generates a direct water reduction under visible light illumination. The hydrogen yield of 10% NiO/γ–Al2O3 was compared with those produced with NiO alone.

Ternary oxides are practically employed in most technological fields and continue to attract much interest because of their low cost and simple preparation. In this work, we have synthesized La2NiO4 by sol-gel method and characterized by X-ray diffraction, BET surface area, SEM analysis, laser granulometry and electrical conductivity. The XRD pattern shows that the pure La2NiO4 is obtained beyond 900 °C. The BET measurements give relatively a small surface area (10 m2 g−1). The elemental chemical analysis by laser granulometry, confirmed the agglomerated nature of the synthesized powder observed by SEM analysis and attributed to the fine powder obtained by sol-gel method. The diffuse reflectance gives an optical gap of 1.3 eV, in agreement with the dark color. The transport properties show a semi-conductor behavior with p-type conductivity and activation energy of 44 meV. The results of the absorption analysis show that La2NiO4 exhibits an excellent chemical stability in the pH range (6–14). The capacitance measurement (C−2-E) in basic electrolyte reveals a linear behavior from which a flat band potential of 0.1 VSCE is obtained. La2NiO4 is tested successfully as photocatalyst for the hydrogen production upon visible light and the best performance is obtained in alkaline solution (NaOH 0.1 M, Na2S2O3 10−3 M) with an average rate of 23.6 μmol mn−1 (g catalyst)−1. The system shows a tendency toward saturation whose deceleration is the result of the competitive reduction of the end product S4O62−.

Algeria’s energy mix is almost exclusively based on fossil fuels (Meriem in Renewable Energy in Algeria Reality and Perspective, pp. 1–19, 2018) [1], especially natural gas. However, the country has enormous renewable energy potential, mainly solar, which the government is trying to harness by launching an ambitious renewable energy and energy efficiency programs (Ministry of Energy and Mining of Algeria in Renewable Energy and Energy Efficiency Program, 2011) [2]. Despite being a hydrocarbon-rich nation, Algeria is making efforts to harness its renewable energy potential. The renewable energies could represent an economic solution for the case of isolated sites, but their intermittency needs a storage system, that could be either by the use of batteries or hydrogen technologies. However, these two storage systems still face challenges, especially economic ones. This study deals with an economic study of several configurations of renewable energy systems, it aims to compare between the conventional storage systems and the new technologies of the hydrogen. In this study, HOMER will be used to simulate three configurations for a school on the high land region of Algeria named Had-Saharry. Many configurations will be simulated using HOMER in order to have an over view about the techno-economic feasibility and the use of hydrogen for the storage. The system has been designed according to the school’s load profile. Then compare between the costs of the systems and their performance on the Algerian high lands weather conditions. As result the systems with batteries proved to be less expensive than the hydrogen storage, as well as, the hybrid system (PV, WECS) proved to be cost effective.

This paper deals with the development of a single sensor neural network controller used to track the maximum power of proton exchange membrane fuel cell power system. The proposed single sensor neural network controller has been developed and trained using single sensor maximum power point tracking data obtained previously. The developed maximum power point tracking controller has been used to track the output power of the fuel cell power system composed of 7 kW proton exchange membrane fuel cell powering a resistive load via a DC-DC boost converter controlled using the proposed controller. Simulation results obtained using the developed MATLAB/Simulink model show that the proposed single sensor neural network maximum power point tracking controller can track effectively the maximum power using only one sensor compared to the classical power point tracking controllers using two sensors reducing by the way the cost and the complexity of the fuel cell maximum power tracking controller.

This paper proposes a modified perturb and observe based fuzzy type-2 maximum power point controller. In this study the fuzzy type-2 controller has been used to drive the variable step size of classical perturb and observe algorithm in order to track the maximum power point of the proton exchange membrane fuel cell power system. The proposed controller has been validated using the Matlab/Simulink environment where the whole fuel cell power system composed of 7 kW proton exchange membrane fuel cell powering a resistive load via a DC-DC boost converter controlled using the proposed controller have been implemented. The developed model has been investigated in case of temperature variation. Comparative simulation results obtained using the classical perturb and observe algorithm, the fuzzy type- 1 algorithm and the proposed fuzzy type-2 algorithm prove the superiority of the proposed controller to track effectively the maximum power regarding used dynamic and static performance metrics.

In this paper, an optimal design of a grid-connected PV-battery-hydrogen hybrid renewable energy system (HRES) at a University campus in Ouargla, Algeria is carried out. To achieve this goal, geographical information system (GIS), CAD software and multi-objective particle swarm optimization (MOPSO) are used. First, the rooftop’s solar energy potential, optimal zones to install PV panels and selection of the PV system’s best installation are determined, considering many design criteria. Thus, based on these outcomes, optimal sizing of the proposed hybrid system is then performed using MATLAB. Cost of energy, loss of power supply probability, and renewable usage are the objectives to be optimized. Here, an energy management strategy is adopted to select the most adequate storage option at each simulation time step. In this study, selling of the excess hydrogen gas has suggested instead of selling electricity to the grid. Results show that standard multi crystalline PV panels with an inclination angle of 17° is the best installation. In addition, the obtained optimal HRES, which includes PV/battery/hydrogen has a renewable usage of 90%, and cost of energy of only 0.22 $/kWh with high reliability.

The optimization of hydrogen storage within metal hydride reactors is one of the main issues in the recent works. The aim of this paper is to compare between two hydrogen injection modes within a hydrogen tank in terms of heat transport. The charging process in the cylindrical tank is releasing heat because it undergoes an exothermic reaction. In order to guarantee a maximum absorption of hydrogen from the alloy (LaNi5), a heat exchanger along the cylindrical walls is considered. Two hydrogen injection modes have been considered in this study: (1) injection from the top, (2) injection from the axis of the cylinder. The governing equations based on mass, heat and momentum balances are transient and two-dimensional. The results show that axial injection is more advantageous than the top one, since it ensures a better heat transfer within the hydride bed and therefore helps to absorb the maximum amount of hydrogen in a shorter time.

The Ion conductors are used as electrolytes in high temperature Solid Oxide Fuel Cells SOFCs. The preparation route has an important role on their structural and electrical properties. In this study, we used a modified Pechini method to prepare an ionic conductor based on lanthanum aluminate doped with strontium La1−xSrxAlO3−δ (x = 0.0.05, 0.1, 0.15). The effect of two complexing agents on structural and electrical properties was studied, we used Ethylene Diamine Tetra Acetic EDTA, and tartaric acid TA as complexing agents. The perovskite phases were obtained at 900 °C and characterized by different techniques; SEM images show that grain size is in the nanometer range, XRD analysis shows that the compounds prepared by use of the two complexing agents crystallize in a perovskite structure with an orthorhombic system and an R3m space group, the doped phases prepared by EDTA have a secondary phase LaSrAl3O7 which is absent in the compounds prepared by tartaric acid. The determination of the ionic conductivity by electrochemical impedance spectroscopy shows clearly the effect of the complexing agent. Indeed we have found that the value of the ionic conductivity is higher for the phases produced by the Pichini method in the presence of tartaric acid as complexing agent.

Flash pyrolysis is used for chemical valorization of lignocellulosic biomass in an entrained bed reactor for the bio-oil production from wood particles of 350 µm diameter. The experimental conditions were selected by predicting the spatio-temporal temperature profile of the biomass particles. These calculations are used to compare different tests carried out under different operating conditions. The experiments were implemented in the temperature range between 400 and 550 °C and at different residence times (1.07, 1.64 and 2.74 s). The quality of the bio-oil depends essentially on the heating rate, temperature and the effective residence time of the particles at gas temperature. Long residence time slows down the heating rate of the particles and extends the effective residence time of the condensable gases. The secondary reactions intensify the cracking of the condensable vapors and induce the production of CO and CH4 from furan decomposition and primary lignin degradation products.

Hydrogen production driven by renewable energy sources (RES) represents an attractive energy solution to global warming. This paper deals with site selection problems for wind hydrogen production and aims to propose a structural procedure for determining the suitable sites. The study area is Algeria. The methodology focuses on the combined use of geographic information systems (GIS) and multi-criteria decision making (MCDM), aiming to provide a decision tool for wind hydrogen production sites. The first stage excludes sites that are infeasible for wind hydrogen production, based on land use, water bodies, water ways, roads, railways, power lines, and also their buffer around these zones. The second stage weighting criteria will be chosen according to the objective to be reached, in this case they will be distance to roads, to railways, to power lines, hydrogen demand, wind hydrogen potential, digital elevation models (DEMs), and slope. Through the use of MCDM the criteria mentioned will be weighted in order to evaluate potential sites to produce hydrogen from wind energy. Analysis and calculation of the weights of these criteria will be conducted using SWING weighting method. The overlaid result map showed that 23.59% (561,836 km2) of the study area is promising and suitable for deploying wind hydrogen farms while the most suitable areas to be in the southwest of the Algeria. It has been found that suitable lands are following the pattern of the wind hydrogen potential. The integration of the GIS with MCDM methods is a powerful tool to deal with a geographical information data and vast area as well as manipulate criteria importance towards introducing the best sites for wind hydrogen production.

Hydrogen, under atmospheric pressure, becomes liquid at 20.3 K. The liquefaction is carried out by extracting of 4914 kJ/kg of heat. This liquefaction requires the use of some high level cryogenic technology whether to liquefy it or to keep it in the liquid state. In general, three processes are applied: Claude cycle, Brayton cycle and liquefaction by magnetocaloric effects (Magnetic Refrigeration). The present work aims at performing comparison between conventional liquefaction and magnetic liquefaction systems. It deals with a comparison between performances and energy consumption evaluated for the two systems at similar operating conditions. Precooled Claude liquefaction cycle has been considered for the first one. Here, energy and material balances has been performed by use of Aspen Hysys simulator. However, the second one is based on a multistage Active Magnetic Regenerator (AMR) cycles operating with real magnetic materials. A new simulation method has been proposed to use Aspen Hysys simulator for thermal analysis of the AMR liquefier.

In this work, we studied numerically the two dimensional phenomena of heat and mass transfer during the exothermic chemical reaction of hydrogen absorption. These phenomena take place within a thin disk drive filled with a metallic powder of LaNi5 and crossed by cooling and injection tubes of hydrogen gas. A cooling jacket, surrounding its peripheral surface has been added. The commercial ANSYS FLUENT R17.2 CFD simulation code has been used to perform a series of numerical investigations of the arrangement effect of the incorporated cooling tubes, on the heat and mass transfers during the storage process of hydrogen. For the selected optimal configuration, we illustrated the temperature contours for the four configurations proposed at different times and the time average of temperature bed as well as the fraction hydrogen absorbed are assessed in the history curves. Our simulation results have been validated by experimental results found in the literature, and a good agreement has been noticed, which confirms the reliability of our simulation procedure.

The hetero-junction 5% CuO/ZnO elaborated by co-precipitation is studied by thermal analysis, X-ray diffraction, ATR spectroscopy, and optical reflectance to assess its performance for the H2 photoproduction. The specific surface area averages ~7 m2 g−1 while the crystallite size varies from 20 to 50 nm. The diffuse reflectance spectra shows an indirect transition at 3.13 eV for ZnO and a direct transition at 1.60 eV for CuO. The capacitance-potential plot of the sensitizer CuO exhibits p-type conduction, due copper deficiency, with a flat band potential of 0.075 VSCE. ZnO works as an electron bridge; its conduction band of ZnO (−0.68 VSCE) is cathodically localized with respect to that of CuO and CuOH2O/H2 level (~−0.5 VSCE), yielding H2 evolution under visible light illumination. H2 liberation rate of 340 µmol h−1 (g catalyst)−1 and a quantum yield of 0.38% were obtained under full light (27 mW cm−2) for a catalyst dose of 0.25 mg/mL and pH ~ 7 in presence of $${{\text{SO}}_{3}}^{2 - }$$ SO 3 2 - as reducing agent; H2 liberation rate of 340 µmol h−1 (g catalyst)−1 and a quantum yield of 0.38% are determined.

The improvement in the electromagnetic field energy density around planar surfaces of hydrogen-absorbing metals is necessary for the development of effective hydrogen storage technologies. We explore in this research the possibility to substitute the planar metal by a planar metamaterial in order to enhance the field enhancement factor. Metamaterials are artificial materials with, in a certain frequency region, simultaneously negative effective electric permittivity and negative effective magnetic permeability. A comparison of the field enhancement factor is undertaken for structures with a planar metamaterial and a planar metal with, respectively, negative and positive real part of refractive indices. This research takes into account the reflectivity at the metamaterial hydrogen interface. This reflectivity is determined by the Transfer Matrix Method. The dependence of the field enhancement factor on the metamaterial thickness is also discussed. The computational results show an increasing of the field enhancement factor of the planar metamaterial compared to the field enhancement factor of the planar metal.

The NiAl and NiAlSi were prepared by coprecipitation method at constant basic pH, calcined at 800 °C, and characterized by ICP analysis, XRD, FTIR, SEM, BET method and (TPR). The CH4/CO2 reaction was carried out in a fixed-bed tubular reactor at 750 °C. A reactant mixture CH4 and CO2 were mixed at a ratio of 1 diluted in He (10:10:80). The XRD patterns of the “as prepared” materials exhibit the characteristic diffractions of hydrotalcite-like layered double hydroxide materials, although were not clearly evidenced in the Si containing samples. Nevertheless, after calcination this hydroltacite-like structure is destroyed. We have studied the reaction of dry reforming of methane by carbon dioxide in presence of various catalysts at 750 °C. In the case of NiAlSi, the CH4 conversions were close to 70%, with a H2/CO ratio close to 0.9. Nevertheless, the NiAl sample presented a very variable conversion and a high carbon formation, what resulted in a blocking of the reactor at the end of the experience and a decrease in the H2/CO ratio, which indicates that probably the CO2 is consumed in parallel in the reverse water gas shift reaction (RWGS). We have shown that Ni/Al/Si mixed oxides obtained through the thermal decomposition of layered double hydroxide-type precursors are promising catalysts in the reforming of methane with CO2.

Hydrogen has a significant importance through its benefit for sustainable energy producing that can respond to the worldwide demand and address environmental problems. It can be used as an alternative resource for the generation of clean and renewable fuels via Fischer-Tropsch synthesis (FT). In this context, our investigation focuses on studying the impact of injected amount of hydrogen on reactor outlet for assuring readily control and manage of the distribution of the products. For this purpose, a simulation study by using a mathematical model of FT synthesis carried out in a packed bed reactor was established under various values of molar flow rate of hydrogen at constant carbon monoxide flow rate. It was found that increasing the inlet hydrogen to carbon monoxide molar ratio was able to shift the distribution of hydrocarbons towards the production of paraffins. Either, the optimal reactor performances were also could be achieved at high injection of hydrogen.

Due to the use of nonlinear loads, the current quality at the point of common coupling (PCC) is degraded. To improve this, a three-phase double-stage multifunctional grid-connected inverter interfaced with a fuel cell–photovoltaic based hybrid system is proposed with embedded active filter function. The studied system consists of a fuel cell stack, a photovoltaic array, a dc-dc boost converter and a three-phase voltage source inverter connected to the utility at the PCC. The objective of the proposed system is to supply the nonlinear currents by the fuel cell–photovoltaic inverter, and thus, the grid current will become sinusoidal with low harmonics. The control of system is performed via P&O MPPT and predictive current control, which uses a discrete-time model of the system to predict the future value of the filter current for different voltage vectors. Simulation in MATLAB is carried out to verify the operation and the control principle. The results are obtained for different operating conditions to prove the effectiveness of the entire system.

Efficiency of photo-hydrogen production is highly dependent on the culture conditions. Initial pH, temperature were optimized for maximal hydrogen production using response surface methodology with central composite design. Photo fermentative hydrogen production is influenced by several parameters, including pH and temperature. Rhodobacter sp. KKU-PS1 was isolated from the methane fermentation broth of an UASB reactor. This study presents the experimental results obtained from Rhodobacter sp. KKU-PS1 cultures as a function of temperature and pH. For this purpose, a complete factorial design was used, for the temperatures of 26, 30 and 34 °C and the pH of 6.5; 7 and 7.5. Rhodobacter sp. KKU-PS1 has been isolated from the fermentation of methane. Optimum conditions for maximizing cumulative hydrogen production (Hmax) were an initial value of pH 7.0 and a temperature of 25 °C. The regression models revealed a maximum hydrogen production of 1623 ml at these conditions. KKU-PS1 can produce hydrogen from organic acids. By optimizing the pH and the temperature, a maximal production of hydrogen by this strain was obtained. Validation experiments at calculated optima confirmed these results.

Great increasing interest in both commercial community and research on the production of hydrogen in the energy sector as an energy carrier. In addition, protecting our earth from global warming and the depletion of crude oils and gasses are the main objectives for our energy strategies worldwide. The Westinghouse Corporation proposed a new method known as the Hybrid Sulphur (HyS) cycle, which forms part of the so-called thermo-chemical cycles. Two sub-reactions in this system are used to complete the functionality of this process: thermochemical and electrochemical reactions. In the second sub-reaction, several parameters can affect the electrochemical reaction and electrolysis efficiency such as: cell temperature, membrane thickness and catalyst loading … etc. This study will focus on the influence solar irradiation and ambient temperature on hydrogen production in three cities in the north of Algeria. According to the study, it was found that the power consumption to produce a flow 8 Nm3/h is 31 kWh for Algiers and 32 kWh for Constantine and Oran.

Algeria is endowed with one of the world’s largest solar potential. Therefore, photovoltaic effect is one of the most common techniques used in exploiting this huge potential. Nevertheless, the amount of energy generated by solar PV panels is influenced by several factors. Indeed, PV cells technologies, site location and weather (solar radiation, temperature and wind speed) and system design (tracking and orientation) determine the output power of PV solar systems. This paper investigated PV-Hydrogen production by two water electrolyzers technologies, alkaline and PEM. Indeed, four different PV systems configurations, two fixed PV panels and two solar tracking system, have been considered. All these cases are studied using meteorological data of the site of Ghardaïa, in the south of Algeria. Thus, a photovoltaic system of about 1.6 kW supplies an electrolysis system of about 1.35 kW across an MPPT (Maximum Power Point Tracking) and buck DCDC converters. The annual hydrogen production shows the advantage of PEM technology in hydrogen production as well as that of sun trackers for PV systems.

Wind energy is one of the most competitive renewable energy sources for providing energy to isolated area where the extension of the national grid is prohibitively expensive, or fossil fuel supply is difficult. The present work aims to evaluate the amount of energy and hydrogen produced from wind energy source over the site of Hassi R’mel, using hourly wind data (speed and direction) stretching from 2003 to 2017. As well as, estimating the cost of energy and hydrogen for large wind turbines. To this end, a model of wind-hydrogen system has been developed under Simulink environment, the main components are, a wind turbine to produce electricity from wind energy, an electrolyzer unit to produce hydrogen from the produced electricity by electrolysis technique, and a tank for hydrogen storage. The study pointed out, that the site of Hassi R’mel has an important wind potential with mean speed exceeding 6 m/s, and more profitable and adapted for wind energy conversion systems installation. The low cost of energy and hydrogen of 0.053 $/kWh, and 25.27 $/kg H2 respectively, is obtained by the Nordex N100 wind turbine at 100 m.

This paper seeks to address an application using a small PEM fuel cell system (Heliocentris FC50), this one uses a solar hydrogen fuel in order to power a known electric load, hence, a series of experiments have been conducted in LAGE Laboratory at Ouargla University, that the effect of operating temperature on (I-V) fuel cell characteristics have been investigated, another tests were conducted to determine the relation between the hydrogen input flow and the available output power from the fuel cell, hence the photovoltaic-hydrogen system components are properly sized in order to fulfil the daily cycle energy needs, a computer program also has been developed to size system components in order to match the load of the site in the most effective way. Consequently, one scenario configuration is proposed, which covered the right balance and no power supply interruption to the proposed load.

In this paper, a novel system for hydrogen production is presented. Usually, an Organic Rankine Cycle (ORC) machine driven by geothermal energy is used to produce electric energy and then hydrogen. This method is efficient for high geothermal enthalpy only. In our system, we use thermoelectric generators TEG instead of ORC machine. For low geothermal temperature resources, (temperature below 100 °C), the thermoelectric generator TEG can provide electricity with a low heat source temperature, it has no moving parts, and is compact, quiet, highly reliable and environmentally friendly as it has no greenhouse gas emissions. Therefore, the system can operate over an extended period with minimal maintenance. This new model of electric generator allows us to configure the voltage and the current according to the type of electrolyze by using some TEG connected in parallel and in series. For this study, we used the thermoelectric module TEC1-12706. The simulation of the system show that the production of hydrogen depend of the temperature difference between hot side and cold side of the thermoelectric module. As example, the result show that for ∆T = 40 °C, produced hydrogen is 0.02 m3/h.

“Chaurasia, A.K., Mondal, P. (2021). Simultaneous Removal of Organic Load and Hydrogen Gas Production Using Electrodeposits Cathodes in MEC. In: Khellaf, A. (eds) Advances in Renewable Hydrogen and Other Sustainable Energy Carriers. Springer Proceedings in Energy. Springer, Singapore. https://doi.org/10.1007/978-981-15-6595-3_34