Egypt
Recent Application of Nanomaterials to Overcome Technological Challenges of Microbial Electrolysis Cells
Apr 2022
Publication
Microbial electrolysis cells (MECs) have attracted significant interest as sustainable green hydrogen production devices because they utilize the environmentally friendly biocatalytic oxidation of organic wastes and electrochemical proton reduction with the support of relatively lower external power compared to that used by water electrolysis. However the commercialization of MEC technology has stagnated owing to several critical technological challenges. Recently many attempts have been made to utilize nanomaterials in MECs owing to the unique physicochemical properties of nanomaterials originating from their extremely small size (at least <100 nm in one dimension). The extraordinary properties of nanomaterials have provided great clues to overcome the technological hurdles in MECs. Nanomaterials are believed to play a crucial role in the commercialization of MECs. Thus understanding the technological challenges of MECs the characteristics of nanomaterials and the employment of nanomaterials in MECs could be helpful in realizing commercial MEC technologies. Herein the critical challenges that need to be addressed for MECs are highlighted and then previous studies that used nanomaterials to overcome the technological difficulties of MECs are reviewed.
Exergy and Exergoeconomic Analysis for the Proton Exchange Membrane Water Electrolysis under Various Operating Conditions and Design Parameters
Nov 2022
Publication
Integrating the exergy and economic analyses of water electrolyzers is the pivotal way to comprehend the interplay of system costs and improve system performance. For this a 3D numerical model based on COMSOL Multiphysics Software (version 5.6 COMSOL Stockholm Sweden) is integrated with the exergy and exergoeconomic analysis to evaluate the exergoeconomic performance of the proton exchange membrane water electrolysis (PEMWE) under different operating conditions (operating temperature cathode pressure current density) and design parameter (membrane thickness). Further the gas crossover phenomenon is investigated to estimate the impact of gas leakage on analysis reliability under various conditions and criteria. The results reveal that increasing the operating temperature or decreasing the membrane thickness improves both the efficiency and cost of hydrogen exergy while increasing the gas leakage through the membrane. Likewise raising the current density and the cathode pressure lowers the hydrogen exergy cost and improves the economic performance. The increase in exergy destroyed and hydrogen exergy cost as well as the decline in second law efficiency due to the gas crossover are more noticeable at higher pressures. As the cathode pressure rises from 1 to 30 bar at a current density of 10000 A/m2 the increase in exergy destroyed and hydrogen exergy cost as well as the decline in second law efficiency are increased by 37.6 kJ/mol 4.49 USD/GJ and 7.1% respectively. The cheapest green electricity source which is achieved using onshore wind energy and hydropower reduces hydrogen production costs and enhances economic efficiency. The growth in the hydrogen exergy cost is by about 4.23 USD/GJ for a 0.01 USD/kWh increase in electricity price at the current density of 20000 A/m2. All findings would be expected to be quite useful for researchers engaged in the design development and optimization of PEMWE.
Prospects of Fuel Cell Combined Heat and Power Systems
Aug 2020
Publication
Combined heat and power (CHP) in a single and integrated device is concurrent or synchronized production of many sources of usable power typically electric as well as thermal. Integrating combined heat and power systems in today’s energy market will address energy scarcity global warming as well as energy-saving problems. This review highlights the system design for fuel cell CHP technologies. Key among the components discussed was the type of fuel cell stack capable of generating the maximum performance of the entire system. The type of fuel processor used was also noted to influence the systemic performance coupled with its longevity. Other components equally discussed was the power electronics. The thermal and water management was also noted to have an effect on the overall efficiency of the system. Carbon dioxide emission reduction reduction of electricity cost and grid independence were some notable advantages associated with fueling cell combined heat and power systems. Despite these merits the high initial capital cost is a key factor impeding its commercialization. It is therefore imperative that future research activities are geared towards the development of novel and cheap materials for the development of the fuel cell which will transcend into a total reduction of the entire system. Similarly robust systemic designs should equally be an active research direction. Other types of fuel aside hydrogen should equally be explored. Proper risk assessment strategies and documentation will similarly expand and accelerate the commercialization of this novel technology. Finally public sensitization of the technology will also make its acceptance and possible competition with existing forms of energy generation feasible. The work in summary showed that proton exchange membrane fuel cell (PEM fuel cell) operated at a lower temperature-oriented cogeneration has good efficiency and is very reliable. The critical issue pertaining to these systems has to do with the complication associated with water treatment. This implies that the balance of the plant would be significantly affected; likewise the purity of the gas is crucial in the performance of the system. An alternative to these systems is the PEM fuel cell systems operated at higher temperatures.
A Comparison between Fuel Cells and Other Alternatives for Marine Electric Power Generation
Mar 2016
Publication
The world is facing a challenge in meeting its needs for energy. Global energy consumption in the last half-century has increased very rapidly and is expected to continue to grow over the next 50 years. However it is expected to see significant differences between the last 50 years and the next. This paper aims at introducing a good solution to replace or work with conventional marine power plants. This includes the use of fuel cell power plant operated with hydrogen produced through water electrolysis or hydrogen produced from natural gas gasoline or diesel fuels through steam reforming processes to mitigate air pollution from ships.
Synthesis and Characterization of Biogenic Iron Oxides of Different Nanomorphologies from Pomegranate Peels for Efficient Solar Hydrogen Production
Feb 2020
Publication
An eco-friendly green synthesis of mesoporous iron oxide (hematite) using pomegranate peels through a low-cost and massive product method was investigated. The mass of pomegranate peels was varied to control the morphology of the produced hematite (Fe2O3). The structures textures and optical properties of the products were investigated by FTIR XRD FE-SEM and UV–Vis spectroscopy. Three different Fe2O3 morphologies were obtained; Fe2O3(I) nanorod like shape Fe2O3(II) nanoparticles and Fe2O3(III) nanoporous structured layer. The bandgap values for Fe2O3 (I) (II) and (III) were 2.71 2.95 and 2.29 eV respectively. The newly hematite samples were used as promising photoelectrodes supported on graphite substrate for the photoelectrochemical (PEC) water splitting toward the efficient production of solar hydrogen. The number of generated hydrogen moles was calculated per active area to be 50 molh−1 cm−2 for electrode III which decreased to 15.3molh−1 cm−2 for electrode II. The effects of temperature (30–70 ◦C) on the PEC behavior of the three electrodes were addressed. Different thermodynamic parameters were calculated for the three electrodes which showed activation energies of 13.4 16.8 and 15.2 kJmol−1 respectively. The electrode stability was addressed as a function of the number of runs and exposure time in addition to electrochemical impedance study. Finally the conversion efficiency of the incident photon to-current(IPCE) was estimated under the monochromatic illumination. The optimum value was ∼11% @ 390nm for Fe2O3(III) electrode
Effect of Carbon Concentration and Carbon Bonding Type on the Melting Characteristics of Hydrogen-reduced Iron Ore Pellets
Oct 2022
Publication
Decarbonization of the steel industry is one of the pathways towards a fossil-fuel-free environment. The steel industry is one of the top contributors to greenhouse gas emissions. Most of these emissions are directly linked to the use of a fossil-fuelbased reductant. Replacing the fossil-based reductant with green H2 enables the transition towards a fossil-free steel industry. The carbon-free iron produced will cause the refining and steelmaking operations to have a starting point far from today’s operations. In addition to carbon being an alloying element in steel production carbon addition controls the melting characteristics of the reduced iron. In the present study the effect of carbon content and form (cementite/graphite) in hydrogen-reduced iron ore pellets on their melting characteristics was examined by means of a differential thermal analyser and optical dilatometer. Carburized samples with a carbon content < 2 wt % did not show any initial melting at the eutectic temperature. At and above 2 wt % the carburized samples showed an initial melting at the eutectic temperature irrespective of the carbon content. However the absorbed heat varies with varied carbon content. The carbon form does not affect the initial melting temperature but it affects the melting progression. Carburized samples melt homogenously while melting of iron-graphite mixtures occurs locally at the interface between iron and carbon particles and when the time is not long enough melting might not occur to any significant extent. Therefore at any given carbon content > 2 wt % the molten fraction is higher in the case of carburized samples which is indicated by the amount of absorbed melting heat.
Hydrogen Energy Storage: New Techno-economic Emergence Solution Analysis
Aug 2015
Publication
The integration of various renewable energy sources as well as the liberalization of electricity markets are established facts in modern electrical power systems. The increased share of renewable sources within power systems intensifies the supply variability and intermittency. Therefore energy storage is deemed as one of the solutions for stabilizing the supply of electricity to maintain generation-demand balance and to guarantee uninterrupted supply of energy to users. In the context of sustainable development and energy resources depletion the question of the growth of renewable energy electricity production is highly linked to the ability to propose new and adapted energy storage solutions. The purpose of this multidisciplinary paper is to highlight the new hydrogen production and storage technology its efficiency and the impact of the policy context on its development. A comprehensive techno/socio/economic study of long term hydrogen based storage systems in electrical networks is addressed. The European policy concerning the different energy storage systems and hydrogen production is explicitly discussed. The state of the art of the techno-economic features of the hydrogen production and storage is introduced. Using Matlab-Simulink for a power system of rated 70 kW generator the excess produced hydrogen during high generation periods or low demand can be sold either directly to the grid owners or as filled hydrogen bottles. The affordable use of Hydrogen-based technologies for long term electricity storage is verified.
Optimal Multi-layer Economical Schedule for Coordinated Multiple Mode Operation of Wind-solar Microgrids with Hybrid Energy Storage Systems
Nov 2023
Publication
The aim of this paper is the design and implementation of an advanced model predictive control (MPC) strategy for the management of a wind–solar microgrid (MG) both in the islanded and grid-connected modes. The MG includes energy storage systems (ESSs) and interacts with external hydrogen and electricity consumers as an extra feature. The system participates in two different electricity markets i.e. the daily and real-time markets characterized by different time-scales. Thus a high-layer control (HLC) and a low-layer control (LLC) are developed for the daily market and the real-time market respectively. The sporadic characteristics of renewable energy sources and the variations in load demand are also briefly discussed by proposing a controller based on the stochastic MPC approach. Numerical simulations with real wind and solar generation profiles and spot prices show that the proposed controller optimally manages the ESSs even when there is a deviation between the predicted scenario determined at the HLC and the real-time one managed by the LLC. Finally the strategy is tested on a lab-scale MG set up at Khalifa University Abu Dhabi UAE.
Review on Ammonia as a Potential Fuel: From Synthesis to Economics
Feb 2021
Publication
Ammonia a molecule that is gaining more interest as a fueling vector has been considered as a candidate to power transport produce energy and support heating applications for decades. However the particular characteristics of the molecule always made it a chemical with low if any benefit once compared to conventional fossil fuels. Still the current need to decarbonize our economy makes the search of new methods crucial to use chemicals such as ammonia that can be produced and employed without incurring in the emission of carbon oxides. Therefore current efforts in this field are leading scientists industries and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector moving through all of the steps in the production distribution utilization safety legal considerations and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes legal barriers that will be faced to achieve its deployment safety and environmental considerations that impose a critical aspect for acceptance and wellbeing and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein this work sets the principles research practicalities and future views of a transition toward a future where ammonia will be a major energy player.
Recent Advances in High-Temperature Steam Electrolysis with Solid Oxide Electrolysers for Green Hydrogen Production
Apr 2023
Publication
Hydrogen is known to be the carbon-neutral alternative energy carrier with the highest energy density. Currently more than 95% of hydrogen production technologies rely on fossil fuels resulting in greenhouse gas emissions. Water electrolysis is one of the most widely used technologies for hydrogen generation. Nuclear power a renewable energy source can provide the heat needed for the process of steam electrolysis for clean hydrogen production. This review paper analyses the recent progress in hydrogen generation via high-temperature steam electrolysis through solid oxide electrolysis cells using nuclear thermal energy. Protons and oxygen-ions conducting solid oxide electrolysis processes are discussed in this paper. The scope of this review report covers a broad range including the recent advances in material development for each component (i.e. hydrogen electrode oxygen electrode electrolyte interconnect and sealant) degradation mechanisms and countermeasures to mitigate them.
Large-scale Underground Hydrogen Storage: Integrated Modeling of a Reservoir-wellbore System
Jan 2023
Publication
Underground Hydrogen Storage (UHS) has received significant attention over the past few years as hydrogen seems well-suited for adjusting seasonal energy gaps. We present an integrated reservoir-well model for “Viking A00 the depleted gas field in the North Sea as a potential site for UHS. Our findings show that utilizing the integrated model results in more reasonable predictions as the gas composition changes over time. Sensitivity analyses show that the lighter the cushion gas the more production can be obtained. However the purity of the produced hydrogen will be affected to some extent which can be enhanced by increasing the fill-up period and the injection rate. The results also show that even though hydrogen diffuses into the reservoir and mixes up with the native fluids (mainly methane) the impact of hydrogen diffusion is marginal. All these factors will potentially influence the project's economics.
Precise Dynamic Modelling of Real-World Hybrid Solar-Hydrogen Energy Systems for Grid-Connected Buildings
Jul 2023
Publication
Hybrid renewable hydrogen energy systems could play a key role in delivering sustainable solutions for enabling the Net Zero ambition; however the lack of exact computational modelling tools for sizing the integrated system components and simulating their real-world dynamic behaviour remains a key technical challenge against their widespread adoption. This paper addresses this challenge by developing a precise dynamic model that allows sizing the rated capacity of the hybrid system components and accurately simulating their real-world dynamic behaviour while considering effective energy management between the grid-integrated system components to ensure that the maximum possible proportion of energy demand is supplied from clean sources rather than the grid. The proposed hybrid system components involve a solar PV system electrolyser pressurised hydrogen storage tank and fuel cell. The developed hybrid system model incorporates a set of mathematical models for the individual system components. The developed precise dynamic model allows identifying the electrolyser’s real-world hydrogen production levels in response to the input intermittent solar energy production while also simulating the electrochemical behaviour of the fuel cell and precisely quantifying its real-world output power and hydrogen consumption in response to load demand variations. Using a university campus case study building in Scotland the effectiveness of the developed model has been assessed by benchmarking comparison between its results versus those obtained from a generic model in which the electrochemical characteristics of the electrolyser and fuel cell systems were not taken into consideration. Results from this comparison have demonstrated the potential of the developed model in simulating the real-world dynamic operation of hybrid solar hydrogen energy systems for grid-connected buildings while sizing the exact capacity of system components avoiding oversizing associated with underutilisation costs and inaccurate simulation.
Thermochemical Looping Technologies for Clean Hydrogen Production – Current Status and Recent Advances
Nov 2022
Publication
This review critically analyses various aspects of the most promising thermochemical cycles for clean hydrogen production. While the current hydrogen market heavily relies on fossil-fuel-based platforms the thermochemical water-splitting systems based on the reduction-oxidation (redox) looping reactions have a significant potential to significantly contribute to the sustainable production of green hydrogen at scale. However compared to the water electrolysis techniques the thermochemical cycles suffer from a low technology readiness level (TRL) which retards the commercial implementation of these technologies. This review mainly focuses on identifying the capability of the state-of-the-art thermochemical cycles to deploy large-scale hydrogen production plants and their techno-economic performance. This study also analyzed the potential integration of the hybrid looping systems with the solar and nuclear reactor designs which are evidenced to be more cost-effective than the electrochemical water-splitting methods but it excludes fossil-based thermochemical processes such as gasification steam methane reforming and pyrolysis. Further investigation is still required to address the technical issues associated with implementing the hybrid thermochemical cycles in order to bring them to the market for sustainable hydrogen production.
Hierarchical Model Predictive Control for Islanded and Grid-connected Microgrids with Wind Generation and Hydrogen Energy Storage Systems
Aug 2023
Publication
This paper presents a novel energy management strategy (EMS) to control a wind-hydrogen microgrid which includes a wind turbine paired with a hydrogen-based energy storage system (HESS) i.e. hydrogen production storage and re-electrification facilities and a local load. This complies with the mini-grid use case as per the IEA-HIA Task 24 Final Report where three different use cases and configurations of wind farms paired with HESS are proposed in order to promote the integration of wind energy into the grid. Hydrogen production surpluses by wind generation are stored and used to provide a demand-side management solution for energy supply to the local and contractual loads both in the grid-islanded and connected modes with corresponding different control objectives. The EMS is based on a hierarchical model predictive control (MPC) in which long-term and short-term operations are addressed. The long-term operations are managed by a high-level MPC in which power production by wind generation and load demand forecasts are considered in combination with day-ahead market participation. Accordingly the hydrogen production and re-electrification are scheduled so as to jointly track the load demand maximize the revenue through electricity market participation and minimize the HESS operating costs. Instead the management of the short-term operations is entrusted to a low-level MPC which compensates for any deviations of the actual conditions from the forecasts and refines the power production so as to address the real-time market participation and the short time-scale equipment dynamics and constraints. Both levels also take into account operation requirements and devices’ operating ranges through appropriate constraints. The mathematical modeling relies on the mixed-logic dynamic (MLD) framework so that the various logic states and corresponding continuous dynamics of the HESS are considered. This results in a mixed-integer linear program which is solved numerically. The effectiveness of the controller is analyzed by simulations which are carried out using wind forecasts and spot prices of a wind farm in center-south of Italy.
Developments in Hydrogen Fuel Cells
Mar 2023
Publication
The rapid growth in fossil fuels has resulted in climate change that needs to be controlled in the near future. Several methods have been proposed to control climate change including the development of efficient energy conversion devices. Fuel cells are environmentally friendly energy conversion devices that can be fuelled by green hydrogen with only water as a by-product or by using different biofuels such as biomass in wastewater urea in wastewater biogas from municipal and agricultural wastes syngas from agriculture wastes and waste carbon. This editorial discusses the fundamentals of the operation of the fuel cell and their application in various sectors such as residential transportation and power generation.
Climate Action for the Shipping Industry: Some Perspectives on the Role of Nuclear Power in Maritime Decarbonization
Feb 2023
Publication
The shipping industry is a major enabler of globalization trade commerce and human welfare. But it is still heavily served by fossil fuels which make it one of the foremost greenhouse gas emitting sectors operational today. It is also one of the hardest to abate segments of the transport industry. As part of the economy-wide climate change mitigation and adaptation efforts it is necessary to consider a low carbon energy transition for this segment as well. This study examines the potential role of nuclear power and cogeneration towards greening this sector and identifies the associated techno-commercial and policy challenges associated with the transition. Quantitative estimates of the economics and investments associated with some of the possible routes are also presented. Alternatives such as nuclear-powered ships along commercial maritime trading routes ships working on nuclear derived green hydrogen ammonia or other sustainable power fuels will enable not only decarbonization of the shipping industry but also allow further diversification of the nuclear industry through non-electric applications of nuclear power and new sector coupling opportunities. In the run-up to the UNFCCC-COP28 meeting in 2023 in UAE nuclear equipped nations heavily engaged in and dependent on maritime trade and commerce should definitely consider nuclear driven decarbonization of shipping and some of the options presented here as part of their climate action strategies.
Techno-Economic Potential of Wind-Based Green Hydrogen Production in Djibouti: Literature Review and Case Studies
Aug 2023
Publication
Disputed supply chains inappropriate weather and low investment followed by the Russian invasion of Ukraine has led to a phenomenal energy crisis especially in the Horn of Africa. Accordingly proposing eco-friendly and sustainable solutions to diversify the access of electricity in the Republic of Djibouti which has no conventional energy resources and is completely energy dependent on its neighboring countries has become a must. Therefore the implementation of sustainable renewable and energy storage systems is nationally prioritized. This paper deals for the first time with the exploitation of such an affordable and carbon-free resource to produce hydrogen from wind energy in the rural areas of Nagad and Bara Wein in Djibouti. The production of hydrogen and the relevant CO2 emission reduction using different De Wind D6 Vestas and Nordex wind turbines are displayed while using Alkaline and Proton Exchange Membrane (PEM) electrolyzers. The Bara Wein and Nagad sites had a monthly wind speed above 7 m/s. From the results the Nordex turbine accompanied with the alkaline electrolyzer provides the most affordable electricity production approximately 0.0032 $/kWh for both sites; this cost is about one per hundred the actual imported hydroelectric energy price. Through the ecological analysis the Nordex turbine is the most suitable wind turbine with a CO2 emission reduction of 363.58 tons for Bara Wein compared to 228.76 tons for Nagad. While integrating the initial cost of wind turbine implementation in the capital investment the mass and the levelized cost of the produced green hydrogen are estimated as (29.68 tons and 11.48 $/kg) for Bara Wein with corresponding values of (18.68 tons and 18.25 $/kg) for Nagad.
Plastic and Waste Tire Pyrolysis Focused on Hydrogen Production—A Review
Dec 2022
Publication
In this review we compare hydrogen production from waste by pyrolysis and bioprocesses. In contrast the pyrolysis feed was limited to plastic and tire waste unlikely to be utilized by biological decomposition methods. Recent risks of pyrolysis such as pollutant emissions during the heat decomposition of polymers and high energy demands were described and compared to thresholds of bioprocesses such as dark fermentation. Many pyrolysis reactors have been adapted for plastic pyrolysis after successful investigation experiences involving waste tires. Pyrolysis can transform these wastes into other petroleum products for reuse or for energy carriers such as hydrogen. Plastic and tire pyrolysis is part of an alternative synthesis method for smart polymers including semi-conductive polymers. Pyrolysis is less expensive than gasification and requires a lower energy demand with lower emissions of hazardous pollutants. Short-time utilization of these wastes without the emission of metals into the environment can be solved using pyrolysis. Plastic wastes after pyrolysis produce up to 20 times more hydrogen than dark fermentation from 1 kg of waste. The research summarizes recent achievements in plastic and tire waste pyrolysis development.
Hydrogen Production, Storage, Utilisation and Environmental Impacts: A Review
Oct 2021
Publication
Dihydrogen (H2) commonly named ‘hydrogen’ is increasingly recognised as a clean and reliable energy vector for decarbonisation and defossilisation by various sectors. The global hydrogen demand is projected to increase from 70 million tonnes in 2019 to 120 million tonnes by 2024. Hydrogen development should also meet the seventh goal of ‘affordable and clean energy’ of the United Nations. Here we review hydrogen production and life cycle analysis hydrogen geological storage and hydrogen utilisation. Hydrogen is produced by water electrolysis steam methane reforming methane pyrolysis and coal gasification. We compare the environmental impact of hydrogen production routes by life cycle analysis. Hydrogen is used in power systems transportation hydrocarbon and ammonia production and metallugical industries. Overall combining electrolysis-generated hydrogen with hydrogen storage in underground porous media such as geological reservoirs and salt caverns is well suited for shifting excess of-peak energy to meet dispatchable on-peak demand.
Optimal Parameter Determination of Membrane Bioreactor to Boost Biohydrogen Production-Based Integration of ANFIS Modeling and Honey Badger Algorithm
Jan 2023
Publication
Hydrogen is a new promising energy source. Three operating parameters including inlet gas flow rate pH and impeller speed mainly determine the biohydrogen production from membrane bioreactor. The work aims to boost biohydrogen production by determining the optimal values of the control parameters. The proposed methodology contains two parts: modeling and parameter estimation. A robust ANIFS model to simulate a membrane bioreactor has been constructed for the modeling stage. Compared with RMS thanks to ANFIS the RMSE decreased from 2.89 using ANOVA to 0.0183 using ANFIS. Capturing the proper correlation between the inputs and output of the membrane bioreactor process system encourages the constructed ANFIS model to predict the output performance exactly. Then the optimal operating parameters were identified using the honey badger algorithm. During the optimization process inlet gas flow rate pH and impeller speed are used as decision variables whereas the biohydrogen production is the objective function required to be maximum. The integration between ANFIS and HBA boosted the hydrogen production yield from 23.8 L to 25.52 L increasing by 7.22%.
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