Saudi Arabia

Power ultrasonic (> 100 kHz) splits water into free radicals and hydrogen. As a result water sonochemistry is considered as an alternative clean and fossil-fuel-free hydrogen production technique. In this research work the impact of rare gases (Xe Ar and He) on the sonochemical production of hydrogen as well as the population of active bubbles has been investigated computationally for various sonicated frequencies (213-515 kHz) and intensities (1-2 W/cm²). It has been found that both the H2 yielding and the bubble population size for H2 yielding are in the order Xe>Ar>He whatever the imposed sonolytic parameters (i.e. frequency and power). These findings were principally ascribed to the thermal conductivity of the saturating gases which is in the reverse order (He>Ar>Xe). Besides the difference between Ar and Xe is condensed in comparison with the He gas. For wave frequencies larger than 213 kHz however all saturating gases (Xe Ar and He) behave identically with the influence of thermal conductivity of these gases on the optimal radius muted. At 213 kHz however this impact is plainly visible (Ropt (Ar and Xe)>Ropt (He)). As per the results obtained helium's inefficiency as a saturating gas for hydrogen production is verified but xenon's maximal efficacy is reached when water is saturated with it. These results support the fewer experimental data reported in this emerging branch of sonochemistry while the discussed results in the present (i.e. noble gases effect on sono-hydrogen production) are treated for the first time consequently our work is considered as a guideline for increasing the efficacy of hydrogen production in a sonochemical reactor.

Hydrogen (H2) as a cleaner fuel has been suggested as a viable method of achieving the decarbonization objectives and meeting increasing global energy demand. However successful implementation of a full-scale hydrogen economy requires large-scale hydrogen storage (as hydrogen is highly compressible). A potential solution to this challenge is injecting hydrogen into geologic formations from where it can be withdrawn again at later stages for utilization purposes. The geostorage capacity of a porous formation is a function of its wetting characteristics which strongly influence residual saturations fluid flow rate of injection rate of withdrawal and containment security. However literature severely lacks information on hydrogen wettability in realistic geological and caprock formations which contain organic matter (due to the prevailing reducing atmosphere). We therefore measured advancing (θa) and receding (θr) contact angles of mica substrates at various representative thermo-physical conditions (pressures 0.1-25 MPa temperatures 308–343 K and stearic acid concentrations of 10−9 - 10−2 mol/L). The mica exhibited an increasing tendency to become weakly water-wet at higher temperatures lower pressures and very low stearic acid concentration. However it turned intermediate-wet at higher pressures lower temperatures and increasing stearic acid concentrations. The study suggests that the structural H2 trapping capacities in geological formations and sealing potentials of caprock highly depend on the specific thermo-physical condition. Thus this novel data provides a significant advancement in literature and will aid in the implementation of hydrogen geo-storage at an industrial scale.

Hydrogen (H₂) is a promising renewable energy source that can replace fossil fuels since it can solve several environmental and economic issues. However the widespread usage of H₂ is constrained by its storage and safety issues. Many researchers consider solid materials with an excellent capacity for H₂ storage and generation as the solution for most H₂-related issues. Among solid materials ammonia borane (abbreviated hereafter as AB) is considered one of the best hydrogen storage materials due to its extraordinary H₂ content and small density. However the process must be conducted in the presence of efficient catalysts to obtain a reasonable amount of generated H₂. Electrospun nanofibrous catalysts are a new class of efficient catalysts that involves the usage of polymers. Here a comprehensive review of the ceramic-supported electrospun NF catalysts for AB hydrolysis is presented with a special focus on catalytic and photolytic performance and preparation steps. Photocatalytic AB hydrolysis was discussed in detail due to its importance and promising results. AB photocatalytic hydrolysis mechanisms under light were also explained. Electrospun catalysts show excellent activity for AB hydrolysis with good recyclability. Kinetics studies show that the AB hydrolysis reaction is independent of AB concentration and the first-order reaction of NF catalysts.

Rapid industrialization is consuming too much energy and non-renewable energy resources are currently supplying the world’s majority of energy requirements. As a result the global energy mix is being pushed towards renewable and sustainable energy sources by the world’s future energy plan and climate change. Thus hydrogen has been suggested as a potential energy source for sustainable development. Currently the production of hydrogen from fossil fuels is dominant in the world and its utilization is increasing daily. As discussed in the paper a large amount of hydrogen is used in rocket engines oil refining ammonia production and many other processes. This paper also analyzes the environmental impacts of hydrogen utilization in various applications such as iron and steel production rocket engines ammonia production and hydrogenation. It is predicted that all of our fossil fuels will run out soon if we continue to consume them at our current pace of consumption. Hydrogen is only ecologically friendly when it is produced from renewable energy. Therefore a transition towards hydrogen production from renewable energy resources such as solar geothermal and wind is necessary. However many things need to be achieved before we can transition from a fossil-fuel-driven economy to one based on renewable energy

A general rise in environmental and anthropogenically induced greenhouse gas emissions has resulted from worldwide population growth and a growing appetite for clean energy industrial outputs and consumer utilization. Furthermore well-established advanced and emerging countries are seeking fossil fuel and petroleum resources to support their aviation electric utilities industrial sectors and consumer processing essentials. There is an increasing tendency to overcome these challenging concerns and achieve the Paris Agreement’s priorities as emerging technological advances in clean energy technologies progress. Hydrogen is expected to be implemented in various production applications as a fundamental fuel in future energy carrier materials development and manufacturing processes. This paper summarizes recent developments and hydrogen technologies in fuel refining hydrocarbon processing materials manufacturing pharmaceuticals aircraft construction electronics and other hydrogen applications. It also highlights the existing industrialization scenario and describes prospective innovations including theoretical scientific advancements green raw materials production potential exploration and renewable resource integration. Moreover this article further discusses some socioeconomic implications of hydrogen as a green resource.

Promoting green hydrogen has emerged as a pivotal discourse in the contemporary energy landscape driven by pressing environmental concerns and the quest for sustainable energy solutions. This paper delves into the multifaceted domain of C-Suite issues about green hydrogen encompassing both technological advancements and policy considerations. The question of whether green hydrogen is poised to become the focal point of the upcoming energy race is explored through an extensive analysis of its potential as a clean and versatile energy carrier. The transition from conventional fossil fuels to green hydrogen is considered a fundamental shift in energy paradigms with far-reaching implications for global energy markets. The paper provides a comprehensive overview of state-of-the-art green hydrogen technologies including fuel cells photocatalysts photo electrocatalysts and hydrogen panels. In tandem with technological advancements the role of policy and strategy in fostering the development of green hydrogen energy assumes paramount significance. The paper elucidates the critical interplay between government policies market dynamics and corporate strategies in shaping the green hydrogen landscape. It delves into policy mechanisms such as subsidies carbon pricing and renewable energy mandates shedding light on their potential to incentivize the production and adoption of green hydrogen. This paper offers a nuanced exploration of C-Suite issues surrounding green hydrogen painting a comprehensive picture of the technological and policy considerations that underpin its emergence as a transformative energy source. As the global community grapples with the imperatives of climate change mitigation and the pursuit of sustainable energy solutions understanding these issues becomes imperative for executives policymakers and stakeholders alike.

Background: Sustainable development requires access to afordable reliable and efcient energy to lift billions of people out of poverty and improve their standard of living. The development of new and renewable forms of energy that emit less CO2 may not materialize quickly enough or at a price point that allows people to attain the standard of living they desire and deserve. As a result a parallel path to sustainability must be developed that uses both renewable and clean carbon-based methods. Hybrid microgrids are promoted to solve various electrical and energy-related issues that incorporate renewable energy sources such as photovoltaics wind diesel generation or a combination of these sources. Utilizing microgrids in electric power generation has several benefts including clean energy increased grid stability and reduced congestion. Despite these advantages microgrids are not frequently deployed because of economic concerns. To address these fnancial concerns it is necessary to explore the ideal confguration of micro-grids based on the quantity quality and availability of sustainable energy sources used to install the microgrid and the optimal design of microgrid components. These considerations are refected in net present value and levelized energy cost. Methods: HOMER was used to simulate numerous system confgurations and select the most feasible solution according to the net present value levelizied cost of energy and hydrogen operating cost and renewable fraction. HOMER performed a repeated algorithm process to determine the most feasible system configuration and parameters with the least economic costs and highest benefits to achieve a practically feasible system configuration. Results: This article aimed to construct a cost-effective microgrid system for Saudi Arabia’s Yanbu city using five configurations using excess energy to generate hydrogen. The obtained results indicate that the optimal configuration for the specified area is a hybrid photovoltaic/wind/battery/generator/fuel cell/hydrogen electrolyzer microgrid with a net present value and levelized energy cost of $10.6 billion and $0.15/kWh. Conclusion: With solar photovoltaic and wind generation costs declining building electrolyzers in locations with excellent renewable resource conditions such as Saudi Arabia could become a low-cost hydrogen supply option even when accounting for the transmission and distribution costs of transporting hydrogen from renewable resource locations to end-users. The optimum confguration can generate up to 32132 tons of hydrogen per year (tH2/year) and 380824 tons per year of CO2 emissions can be avoided.

This research work is the novel state-of-the-art technology performed on multi-cylinder SI engine fueled compressed natural gas emulsified fuel and hydrogen as dual fuel. This work predicts the overall features of performance combustion and exhaust emissions of individual fuels based on AVL Boost simulation technology. Three types of alternative fuels have been compared and analyzed. The results show that hydrogen produces 20% more brake power than CNG and 25% more power than micro-emulsion fuel at 1500 r/min which further increases the brake power of hydrogen CNG and micro-emulsions in the range of 25% 20% and 15% at higher engine speeds of 2500–4000 r/min respectively. In addition the brake-specific fuel consumption is the lowest for 100% hydrogen followed by CNG 100% and then micro-emulsions at 1500 r/min. At 2500– 5000 r/min there is a significant drop in brake-specific fuel consumption due to a lean mixture at higher engine speeds. The CO HC and NOx emissions significantly improve for hydrogen CNG and micro-emulsion fuel. Hydrogen fuel shows zero CO and HC emissions and is the main objective of this research to produce 0% carbon-based emissions with a slight increase in NOx emissions and CNG shows 30% lower CO emissions than micro-emulsions and 21.5% less hydrocarbon emissions than micro-emulsion fuel at stoichiometric air/fuel ratio.

Several research works have investigated the direct supply of renewable electricity to electrolysis particularly from photovoltaic (PV) and wind generator (WG) systems. Hydrogen (H2 ) production based on solar energy is considered to be the newest solution for sustainable energy. Different technologies based on solar energy which allow hydrogen production are presented to study their benefits and inconveniences. The technology of water decomposition based on renewable energy sources to produce hydrogen can be achieved by different processes (photochemical systems; photocatalysis systems photo-electrolysis systems bio-photolysis systems thermolysis systems thermochemical cycles steam electrolysis hybrid processes and concentrated solar energy systems). A comparison of the different methods for hydrogen production based on PV and WG systems was given in this study. A comparative study of different types of electrolyzers was also presented and discussed. Finally an economic assessment of green hydrogen production is given. The hydrogen production cost depends on several factors such as renewable energy sources electrolysis type weather conditions installation cost and the productivity of hydrogen per day. PV/H2 and wind/H2 systems are both suitable in remote and arid areas. Minimum maintenance is required and a power cycle is not needed to produce electricity. The concentrated CSP/H2 system needs a power cycle. The hydrogen production cost is higher if using wind/H2 rather than PV/H2 . The green energy sources are useful for multiple applications such as hydrogen production cooling systems heating and water desalination.

Photocatalysts lead vitally to water purifications and decarbonise environment each by wastewater treatment and hydrogen (H2 ) production as a renewable energy source from waterphotolysis. This work deals with the photocatalytic degradation of ciprofloxacin (CIP) and H2 production by novel silver-nanoparticle (AgNPs) based ternary-nanocomposites of thiolated reducegraphene oxide graphitic carbon nitride (AgNPs-S-rGO2%@g-C3N4 ) material. Herein the optimised balanced ratio of thiolated reduce-graphene oxide in prepared ternary-nanocomposites played matchlessly to enhance activity by increasing the charge carriers’ movements via slowing down charge-recombination ratios. Reduced graphene oxide (rGO) >2 wt.% or < 10 nm. Therefore AgNPs-S-rGO2%@g-C3N4 has 3772.5 µmolg−1 h −1 H2 production which is 6.43-fold higher than g-C3N4 having cyclic stability of 96% even after four consecutive cycles. The proposed mechanism for AgNPs-S-rGO2%@g-C3N4 revealed that the photo-excited electrons in the conduction-band of g-C3N4 react with the adhered water moieties to generate H2 .