Romania

A systematic method for obtaining a novel electrode structure based on PtCoMn ternary alloy catalyst supported on graphitic carbon nanofibers (CNF) for hydrogen evolution reaction (HER) in acidic media is proposed. Ternary alloy nanoparticles (Co0.6Mn0.4 Pt) with a mean crystallite diameter under 10 nm were electrodeposited onto a graphitic support material using a two-step pulsed deposition technique. Initially a surface functionalisation of the carbon nanofibers is performed with the aid of oxygen plasma. Subsequently a short galvanostatic pulse electrodeposition technique is applied. It has been demonstrated that if pulsing current is employed compositionally controlled PtCoMn catalysts can be achieved. Variations of metal concentration ratios in the electrolyte and main deposition parameters such as current density and pulse shape led to electrodes with relevant catalytic activity towards HER. The samples were further characterised using several physico-chemical methods to reveal their morphology structure chemical and electrochemical properties. X-ray diffraction confirms the PtCoMn alloy formation on the graphitic support and energy dispersive X-ray spectroscopy highlights the presence of the three metallic components from the alloy structure. The preliminary tests regarding the electrocatalytic activity of the developed electrodes display promising results compared to commercial Pt/C catalysts. The PtCoMn/CNF electrode exhibits a decrease in hydrogen evolution overpotential of about 250 mV at 40 mA cm⁻² in acidic solution (0.5 M H₂SO₄) when compared to similar platinum based electrodes (Pt/CNF) and a Tafel slope of around 120 mV dec−1 indicating that HER takes place under the Volmer-Heyrovsky mechanismm

This paper presents a case study concerning a plant for hydrogen production and storage having a daily capacity of 100kg. The plant is located in Cluj-Napoca Romania. It produces hydrogen by means of water electrolysis while the energy is provided using solar energy. We performed the calculations for four different technical solutions used for the hydrogen production and storage plant and also we considered three scenarios regarding the sub-systems of the hydrogen production and storage plant efficiency. The conclusion of this study is that one can maximize the conversion of solar radiation into chemical energy in the form of hydrogen by hybridizing the solar hydrogen production system namely using both electrical energy as well as thermal energy in the form of steam.

Purpose- To present an overview of the research and development carried out in a European funded framework 7 (FP7) project called SafeHPower for the implementation of neutron radiography to inspect fatigue cracks in vehicle and storage hydrogen fuel tanks. Project background– Hydrogen (H2) is the most promising replacement fuel for road transport due to its abundance efficiency low carbon footprint and the absence of harmful emissions. For the mass market of hydrogen to take off the safety issue surrounding the vehicle and storage hydrogen tanks needs to be addressed. The problem is the residual and additional stresses experienced by the tanks during the continuous cyclic loading between ambient and storage pressure which can result in the development of fatigue cracks. Steel tanks used as storage containers at service stations and depots and/or the composite tanks lined with steel are known to suffer from hydrogen embrittlement (HE). Another issue is the explosive nature of hydrogen (when it is present in the 18-59% range) where it is mixed with oxygen which can lead to catastrophic consequences including loss of life. Monitoring systems that currently exist in the market impose visual examination tests pressure tests and hydrostatic tests after the tank installation [1] [2]. Three inspection systems have been developed under this project to provide continuous monitoring solutions. Approach and scope- One of the inspection systems based on the neutron radiography (NR) technology that was developed in different phases with the application of varied strategies has been presented here. Monte Carlo (MCNP) simulation results to design and develop a bespoke collimator have been presented. A limitation of using an inertial electrostatic Deuterium-Tritium (D-T) pulsed neutron generator for fast neutron radiography has been discussed. Radiographs from the hydrogen tank samples obtained using thermal neutrons from a spallation neutron source at ISIS Rutherford laboratory UK have been presented. Furthermore radiograph obtained using thermal neutrons from a portable D-T neutron generator has been presented. In conclusion a proof in principle has been made to show that the defects in the hydrogen fuel tank can be detected using thermal neutron radiography.

Hydrides have emerged as strong candidates for energy storage applications and their study has attracted wide interest in both the academic and industry sectors. With clear advantages due to the solid-state storage of hydrogen hydrides and in particular complex hydrides have the ability to tackle environmental pollution by offering the alternative of a clean energy source: hydrogen. However several drawbacks have detracted this material from going mainstream and some of these shortcomings have been addressed by nanostructuring/nanoconfinement strategies. With the enhancement of thermodynamic and/or kinetic behavior nanosized complex hydrides (borohydrides and alanates) have recently conquered new estate in the hydrogen storage field. The current review aims to present the most recent results many of which illustrate the feasibility of using complex hydrides for the generation of molecular hydrogen in conditions suitable for vehicular and stationary applications. Nanostructuring strategies either in the pristine or nanoconfined state coupled with a proper catalyst and the choice of host material can potentially yield a robust nanocomposite to reliably produce H2 in a reversible manner. The key element to tackle for current and future research efforts remains the reproducible means to store H2 which will build up towards a viable hydrogen economy goal. The most recent trends and future prospects will be presented herein.

Dry reforming of hydrocarbons alcohols and biological compounds is one of the most promising and effective avenues to increase hydrogen (H2 ) production. Catalytic dry reforming is used to facilitate the reforming process. The most popular catalysts for dry reforming are Ni-based catalysts. Due to their inactivation at high temperatures these catalysts need to use metal supports which have received special attention from researchers in recent years. Due to the existence of a wide range of metal supports and the need for accurate detection of higher H2 production in this study a systematic review and meta-analysis using ANNs were conducted to assess the hydrogen production by various catalysts in the dry reforming process. The Scopus Embase and Web of Science databases were investigated to retrieve the related articles from 1 January 2000 until 20 January 2021. Forty-seven articles containing 100 studies were included. To determine optimal models for three target factors (hydrocarbon conversion hydrogen yield and stability test time) artificial neural networks (ANNs) combined with differential evolution (DE) were applied. The best models obtained had an average relative error for the testing data of 0.52% for conversion 3.36% for stability and 0.03% for yield. These small differences between experimental results and predictions indicate a good generalization capability.

In this review we provide a short overview of the Molecular Dynamics (MD) method and how it can be used to model the water splitting process in photoelectrochemical hydrogen production. We cover classical non-reactive and reactive MD techniques as well as multiscale extensions combining classical MD with quantum chemical and continuum methods. Selected examples of MD investigations of various aqueous semiconductor interfaces with a special focus on TiO₂ are discussed. Finally we identify gaps in the current state-of-the-art where further developments will be needed for better utilization of MD techniques in the field of water splitting.

Among the many potential future energy sources hydrogen stands out as particularly promising. Because it is a green and renewable chemical process water electrolysis has earned much interest among the different hydrogen production techniques. Seawater is the most abundant source of water and the ideal and cheapest electrolyte. The first part of this review includes the description of the general theoretical concepts: chemical physical and electrochemical that stands on the basis of water electrolysis. Due to the rapid development of new electrode materials and cell technology research has focused on specific seawater electrolysis parameters: the cathodic evolution of hydrogen; the concurrent anodic evolution of oxygen and chlorine; specific seawater catalyst electrodes; and analytical methods to describe their catalytic activity and seawater electrolyzer efficiency. Once the specific objectives of seawater electrolysis have been established through the design and energy performance of the electrolyzer the study further describes the newest challenges that an accessible facility for the electrochemical production of hydrogen as fuel from seawater must respond to for sustainable development: capitalizing on known and emerging technologies; protecting the environment; utilizing green renewable energies as sources of electricity; and above all economic efficiency as a whole.

Hydrogen is the ultimate vector for a carbon-free sustainable green-energy. While being the most promising candidate to serve this purpose hydrogen inherits a series of characteristics making it particularly difficult to handle store transport and use in a safe manner. The researchers’ attention has thus shifted to storing hydrogen in its more manageable forms: the light metal hydrides and related derivatives (ammonia-borane tetrahydridoborates/borohydrides tetrahydridoaluminates/alanates or reactive hydride composites). Even then the thermodynamic and kinetic behavior faces either too high energy barriers or sluggish kinetics (or both) and an efficient tool to overcome these issues is through nanoconfinement. Nanoconfined energy storage materials are the current state-of-the-art approach regarding hydrogen storage field and the current review aims to summarize the most recent progress in this intriguing field. The latest reviews concerning H2 production and storage are discussed and the shift from bulk to nanomaterials is described in the context of physical and chemical aspects of nanoconfinement effects in the obtained nanocomposites. The types of hosts used for hydrogen materials are divided in classes of substances the mean of hydride inclusion in said hosts and the classes of hydrogen storage materials are presented with their most recent trends and future prospects.

A thermodynamic combustion model developed in AVL BOOST software was used in order to evaluate the pollutant emissions performance and efficiency parameters of a spark ignition engine Renault K7M-710 fueled with compressed natural gas hydrogen and blends of compressed natural gas and hydrogen (hythane). Multiple research studies have concluded that for the near future hythane could be the most promising alternative fuel because it has the advantages of both its components. In our previous work the model was validated for the performance and efficiency parameters by comparison of simulation results with experimental data acquired when the engine was fueled with gasoline. In this work the model was improved and can predict the values of pollutant emissions when the engine is running with the studied alternative fuels. As the percentage of hydrogen in hythane is increased the power of the engine rises the brake specific fuel consumption carbon dioxide carbon monoxide and total unburned hydrocarbon emissions decrease while nitrogen oxides increase. The values of peak fire pressure maximum pressure derivative and peak fire temperature in cycle are higher leading to an increased probability of knock occurrence. To avoid this phenomenon an optimum correlation between the natural gas-hydrogen blend the air-fuel ratio the spark advance and the engine operating condition needs to be found.

Following the international trend of using hydrogen as combustible in many industry branches this paper investigates the impact of mixing methane gas with 23% hydrogen (G222) on condensing boilers’ operation. After modeling and testing several boilers with heat exchange surface different designs the authors gathered enough information to introduce a new concept namely High-Performance Condensing Boiler (HPCB). All the boilers that fit into this approach have the same operational parameters at nominal heat load including the CO2 concentrations in flue gases. After testing a flattened pipes condensing boiler a CO2 emission reduction coefficient of 1.1 was determined when converting from methane gas to G222 as combustible. Thus by inserting into the national grid a G222 mixture an important reduction in greenhouse gases can be achieved. For a 28 kW condensing boiler the annual reduction in CO2 emissions averages 1.26 tons value which was experimentally obtained and is consistent with the theoretical evaluation.

Considering the current environmental restrictions particularly those imposed on fossil fuel exploitation hydrogen stands out as a very promising alternative for the power and transportation sectors. This paper investigates the effects of the employment of hydrogen in a K9K automotive diesel engine. Experiments were conducted at a speed of 2000 min−1 with various engine load levels of 40% 55% 70% and 85%; several quantities were monitored to evaluate the performance with hydrogen use in terms of brake-specific energetic consumption (BSEC) fuel economy maximum pressure and heat-release characteristics. It was found that at 55% engine load the engine efficiency increased by 5.3% with hydrogen addition achieving a diesel fuel economy of 1.32 kg/h. The rate of increase of the peak pressure and maximum pressure started to increase as a consequence of the higher fuel quantity that burned in the premixed combustion phase while still remaining within reliable operational limits. The accelerated combustion and augmented heat release rate resulted in a combustion duration that was reduced by 3◦ CA (crank angle degree) achieving a mass fraction burned percentage of 10% to 90% earlier in the cycle and the combustion variability was also influenced. Hydrogen use assured the decrease of CO2 HC NOx and smoke emission levels in comparison with classic fueling.

Variable renewable energy (VRE) has seen rapid growth in recent years. However VRE deployment requires a fleet of dispatchable power plants to supply electricity during periods with limited wind and sunlight. These plants will operate at reduced utilization rates that pose serious economic challenges. To address this challenge this paper presents the techno-economic assessment of flexible power and hydrogen production from integrated gasification combined cycles (IGCC) employing the gas switching combustion (GSC) technology for CO₂ capture and membrane assisted water gas shift (MAWGS) reactors for hydrogen production. Three GSC-MAWGS-IGCC plants are evaluated based on different gasification technologies: Shell High Temperature Winkler and GE. These advanced plants are compared to two benchmark IGCC plants one without and one with CO₂ capture. All plants utilize state-of-the-art H-class gas turbines and hot gas clean-up for maximum efficiency. Under baseload operation the GSC plants returned CO₂ avoidance costs in the range of 24.9–36.9 €/ton compared to 44.3 €/ton for the benchmark. However the major advantage of these plants is evident in the more realistic mid-load scenario. Due to the ability to keep operating and sell hydrogen to the market during times of abundant wind and sun the best GSC plants offer a 6–11%-point higher annual rate of return than the benchmark plant with CO₂ capture. This large economic advantage shows that the flexible GSC plants are a promising option for balancing VRE provided a market for the generated clean hydrogen exists.

The analysis aims to determine the most efficient and cost-effective way of providing power to a remote site. The two primary sources of power being considered are photovoltaics and small wind turbines while the two potential storage media are a battery bank and a hydrogen storage fuel cell system. Subsequently the hydrogen is stored within a reservoir and employed as required by the fuel cell. This strategy offers a solution for retaining surplus power generated during peak production phases subsequently utilizing it during periods when the renewable power sources are generating less power. To evaluate the performance of the hydrogen storage system the analysis included a sensitivity analysis of the wind speed and the cost of the hydrogen subsystem. In this analysis the capital and replacement costs of the electrolyzer and hydrogen storage tank were linked to the fuel cell capital cost. As the fuel cell cost decreases the cost of the electrolyzer and hydrogen tank also decreases. The optimal system type graph showed that the hydrogen subsystem must significantly decrease in price to become competitive with the battery bank.

In the global content regarding the impact on the environmental of the gases emissions resulted from the fossil fuels combustion aspect discussed on the 2015 Paris Climate Conference contribute to the necessity of searching of alternative energy from durable and renewable resources. The purpose of the paper is the use of hydrogen fuelling at truck diesel engine in order to improves engine efficiency and pollutant performance hydrogen being injected into the inlet manifold. Experimental results show better energetic and pollution performance of the dual fuelled engine due to the improvement of the combustion process and reduction of carbon content.

The increase in greenhouse gas emissions as well as the risk of fossil fuel depletion has prompted a transition to electric transportation. The European Union aims to substantially reduce pollutant emissions by 2035 through the use of renewable energies. In aviation this transition is particularly challenging mainly due to the weight of onboard equipment. Traditional electric motors with radial magnetic flux have been replaced by axial magnetic flux motors with reduced weight and volume high efficiency power and torque. These motors were initially developed for electric vehicles with in-wheel motors but have been adapted for aviation without modifications. Worldwide there are already companies developing propulsion systems for various aircraft categories using such electric motors. One category of aircraft that could benefit from this electric motor development is traditionally constructed training aircraft with significant remaining flight resource. Electric repowering would allow their continued use for pilot training preparing them for future electrically powered aircraft. This article presents a study on the feasibility of repowering a classic training aircraft with an electric propulsion system. The possibilities of using either a battery or a hybrid source composed of a battery and a fuel cell as an energy source are explored. The goal is to utilize components already in production to eliminate the research phase for specific aircraft components.

Hydrogen production from natural gas combined with advanced CO2 capture technologies such as iron-based chemical looping (CL) is considered in the present work. The processes are compared to the conventional base case i.e. hydrogen production via natural gas steam reforming (SR) without CO2 capture. The processes are simulated using commercial software (ChemCAD) and evaluated from a technical point of view considering important key performance indicators such as hydrogen thermal output net electric power carbon capture rate and specific CO2 emissions. The environmental evaluation is performed using Life Cycle Analysis (LCA) with the following system boundaries considered: i) hydrogen production from natural gas coupled to CO2 capture technologies based on CL ii) upstream processes such as: extraction and processing of natural gas ilmenite and catalyst production and iii) downstream processes such as: H2 and CO2 compression transport and storage. The LCA assessment was carried out using the GaBi6 software. Different environmental impact categories following here the CML 2001 impact assessment method were calculated and used to determine the most suitable technology. Sensitivity analyses of the CO2 compression transport and storage stages were performed in order to examine their effect on the environmental impact categories.

During the last few years electric and hydrogen vehicles have become an alternative to cars that use internal combustion engines. The number of electric and hydrogen vehicles sold has increased due to support from local governments and because car manufacturers will stop the production of internal combustion engines in the near future. The emissions of these vehicles while being driven are zero but they still have an impact on the environment due to their fuel. In this article an analysis of carbon dioxide (CO2 ) emissions for two types of vehicles: battery electric vehicles (BEVs) powered by electricity and fuel cell electric vehicles (FCEVs) powered by hydrogen is presented. The analysis considers different values for the mix of power generation and hydrogen production options in comparison to other studies. The CO2 emissions were calculated and compared for the two types of vehicles. The results show that the CO2 emissions of BEVs are lower when compared to FCEVs if the hydrogen is obtained from pollutant sources and is higher if the hydrogen is obtained from nuclear power and renewable energy sources. When compared to conventional combustion engine vehicles BEVs have lower CO2 emissions while the emissions of FCEVs are dependent on the hydrogen production method.

The article examines the role of green hydrogen in reducing CO2 emissions in the transition to climate neutrality highlighting both its benefits and challenges. It starts by discussing the production of green hydrogen from renewable sources and provides a brief analysis of primary resource structures for energy production in European countries including Romania. Despite progress there remains a significant reliance on fossil fuels in some countries. Economic technologies for green hydrogen production are explored with a note that its production alone does not solve all issues due to complex and costly compression and storage operations. The concept of impure green hydrogen derived from biomass gasification pyrolysis fermentation and wastewater purification is also discussed. Economic efficiency and future trends in green hydrogen production are outlined. The article concludes with an analysis of hydrogen-methane mixture combustion technologies offering a conceptual framework for economically utilizing green hydrogen in the transition to a green hydrogen economy.

To inject green hydrogen (H2) into the existing natural gas (NG) infrastructure is one way to decarbonize the European energy system. However asset readiness is necessary to be successful. Preliminary analysis and experimental results about the compatibility of hydrogen and natural gas mixtures (H2NG) with the actual gas grids make the scientific community confident about the feasibility. Nevertheless specific technical questions need more research. A significant topic of debate is the impact of H2NG mixtures on the performance of state-ofthe-art fiscal measuring devices which are essential for accurate billing. Identifying and addressing any potential degradation in their metrological performance due to H2NG is critical for decision-making. However the literature lacks data about the gas meters’ technologies currently installed in the NG grids such as a comprehensive overview of their readiness at different concentrations while data are fragmented among different sources. This paper addresses these gaps by analyzing the main characteristics and categorizing more than 20000 gas meters installed in THOTH2 project partners’ grids and by summarizing the performance of traditional technologies with H2NG mixtures and pure H2 based on literature review operators experience and manufacturers knowledge. Based on these insights recommendations are given to stakeholders on overcoming the identified barriers to facilitate a smooth transition.

Oceanic energy sources notably offshore wind and wave power present a significant opportunity to generate green hydrogen through water electrolysis. This approach allows for offshore hydrogen production which can be efficiently transported through existing pipelines and stored in various forms offering a versatile solution to tackle the intermittency of renewable energy sources and potentially revolutionize the entire electrical grid infrastructure. This research focusses on assessing the technical and economic feasibility of this method in six strategic coastal regions in Morocco: Laayoune Agadir Essaouira Eljadida Casablanca and Larache. Our proposed system integrates offshore wind turbines oscillating water column wave energy converters and PEM electrolyzers to meet energy demands while aligning with global sustainability objectives. Significant electricity production estimates are observed across these regions ranging from 14 MW to 20 MW. Additionally encouraging annual estimates of hydrogen production varying between 20 and 40 tonnes for specific locations showcase the potential of this approach. The system’s performance demonstrates promising efficiency rates ranging from 13% to 18% while maintaining competitive production costs. These findings underscore the ability of oceanic energy-driven green hydrogen to diversify Morocco’s energy portfolio bolster water resilience and foster sustainable development. Ultimately this research lays the groundwork for comprehensive energy policies and substantial infrastructure investments positioning Morocco on a trajectory towards a decarbonized future powered by innovative and clean technologies.