Saudi Arabia
Renewable Energy Market Analysis: Africa and its Regions
Jan 2022
Publication
An energy system centred on renewable energy can help resolve many of Africa’s social economic health and environmental challenges. A profound energy transition is not only feasible it is essential for a climate-safe future in which sustainable development prerogatives are met. Renewables are key to overcoming energy poverty providing needed energy services without damaging human health or ecosystems and enabling a transformation of economies in support of development and industrialisation.
Africa is extraordinarily diverse and no single approach will advance its energy future. But efforts must be made to build modern resilient and sustainable energy systems across the continent to avoid trapping economies and societies in increasingly obsolete energy systems that burden them with stranded assets and limited economic prospects.
This report from the International Renewable Energy Agency (IRENA) sets out the opportunities at hand while also acknowledging the challenges Africa faces. It lays out a pathway to a renewables-based energy system and shows that the transition promises substantial gains in GDP employment and human welfare in each region of the continent.
Among the findings:
A large part of Africa has so far been left out of the energy transition:
Africa is extraordinarily diverse and no single approach will advance its energy future. But efforts must be made to build modern resilient and sustainable energy systems across the continent to avoid trapping economies and societies in increasingly obsolete energy systems that burden them with stranded assets and limited economic prospects.
This report from the International Renewable Energy Agency (IRENA) sets out the opportunities at hand while also acknowledging the challenges Africa faces. It lays out a pathway to a renewables-based energy system and shows that the transition promises substantial gains in GDP employment and human welfare in each region of the continent.
Among the findings:
A large part of Africa has so far been left out of the energy transition:
- Only 2% of global investments in renewable energy in the last two decades were made in Africa with significant regional disparities
- Less than 3% of global renewables jobs are in Africa
- In Sub-Saharan Africa electrification rate was static at 46% in 2019 with 906 million people still lacking access to clean cooking fuels and technologies
- Africa has vast resource potential in wind solar hydro and geothermal energy and falling costs are increasingly bringing renewables within reach
- Central and Southern Africa have abundant mineral resources essential to the production of electric batteries wind turbines and other low-carbon technologies
- Renewable energy deployment has grown in the last decade with more than 26 GW of renewables-based generation capacity added. The largest additions were in solar energy
- Average annual investments in renewable energy grew ten-fold from less than USD 0.5 billion in the 2000-2009 period to USD 5 billion in 2010-2020
- Distributed renewable energy solutions including stand-alone systems and mini-grids are playing a steadily growing role in expanding electricity access in off-grid areas and strengthening supply in already connected areas
- The energy transition under IRENA’s 1.5°C Scenario pathway predicts 6.4% higher GDP 3.5% higher economy-wide jobs and a 25.4% higher welfare index than that realised under current plans on average up to 2050
- Jobs created in the renewable energy transition will outweigh those lost by moving away from traditional energy. Every million U.S. dollars invested in renewables between 2020 – 2050 would create at least 26 job-years; for every million invested in energy efficiency at least 22 job-years would be created annually; for energy flexibility the figure is 18
- A comprehensive policy package that combines the pursuit of climate and environmental goals; economic development and jobs creation; and social equity and welfare for society as a whole
- Strong institutions international co-operation (including South- South co-operation) and considerable co-ordination at the regional level
Earth-Abundant Electrocatalysts for Water Splitting: Current and Future Directions
Mar 2021
Publication
Of all the available resources given to mankind the sunlight is perhaps the most abundant renewable energy resource providing more than enough energy on earth to satisfy all the needs of humanity for several hundred years. Therefore it is transient and sporadic that poses issues with how the energy can be harvested and processed when the sun does not shine. Scientists assume that electro/photoelectrochemical devices used for water splitting into hydrogen and oxygen may have one solution to solve this hindrance. Water electrolysis-generated hydrogen is an optimal energy carrier to store these forms of energy on scalable levels because the energy density is high and no air pollution or toxic gas is released into the environment after combustion. However in order to adopt these devices for readily use they have to be low-cost for manufacturing and operation. It is thus crucial to develop electrocatalysts for water splitting based on low-cost and land-rich elements. In this review I will summarize current advances in the synthesis of low-cost earth-abundant electrocatalysts for overall water splitting with a particular focus on how to be linked with photoelectrocatalytic water splitting devices. The major obstacles that persist in designing these devices. The potential future developments in the production of efficient electrocatalysts for water electrolysis are also described.
High Purity, Self-sustained, Pressurized Hydrogen Production from Ammonia in a Catalytic Membrane Reactor
Dec 2021
Publication
The combination of catalytic decomposition of ammonia and in situ separation of hydrogen holds great promise for the use of ammonia as a clean energy carrier. However finding the optimal catalyst – membrane pair and operation conditions have proved challenging. Here we demonstrate that cobalt-based catalysts for ammonia decomposition can be efficiently 2 used together with a Pd-Au based membrane to produce high purity hydrogen at elevated pressure. Compared to a conventional packed bed reactor the membrane reactor offers several operational advantages that result in energetic and economic benefits. The robustness and durability of the combined system has been demonstrated for more than 1000 h on stream yielding a very pure hydrogen stream (>99.97 % H2) and recovery (>90 %). When considering the required hydrogen compression for storage/utilization and environmental issues the combined system offers the additional advantage of production of hydrogen at moderate pressures along with full ammonia conversion. Altogether our results demonstrate the possibility of deploying high pressure (350 bar) hydrogen generators from ammonia with H2 efficiencies of circa 75% without any external energy input and/or derived CO2 emissions.
Intelligent Natural Gas and Hydrogen Pipeline Dispatching Using the Coupled Thermodynamics-Informed Neural Network and Compressor Boolean Neural Network
Feb 2022
Publication
Natural gas pipelines have attracted increasing attention in the energy industry thanks to the current demand for green energy and the advantages of pipeline transportation. A novel deep learning method is proposed in this paper using a coupled network structure incorporating the thermodynamics-informed neural network and the compressor Boolean neural network to incorporate both functions of pipeline transportation safety check and energy supply predictions. The deep learning model is uniformed for the coupled network structure and the prediction efficiency and accuracy are validated by a number of numerical tests simulating various engineering scenarios including hydrogen gas pipelines. The trained model can provide dispatchers with suggestions about the number of phases existing during the transportation as an index showing safety while the effects of operation temperature pressure and compositional purity are investigated to suggest the optimized productions.
Converting Sewage Water into H2 Fuel Gas Using Cu/CuO Nanoporous Photocatalytic Electrodes
Feb 2022
Publication
This work reports on H2 fuel generation from sewage water using Cu/CuO nanoporous (NP) electrodes. This is a novel concept for converting contaminated water into H2 fuel. The preparation of Cu/CuO NP was achieved using a simple thermal combustion process of Cu metallic foil at 550 ◦C for 1 h. The Cu/CuO surface consists of island-like structures with an inter-distance of 100 nm. Each island has a highly porous surface with a pore diameter of about 250 nm. X-ray diffraction (XRD) confirmed the formation of monoclinic Cu/CuO NP material with a crystallite size of 89 nm. The prepared Cu/CuO photoelectrode was applied for H2 generation from sewage water achieving an incident to photon conversion efficiency (IPCE) of 14.6%. Further the effects of light intensity and wavelength on the photoelectrode performance were assessed. The current density (Jph) value increased from 2.17 to 4.7 mA·cm−2 upon raising the light power density from 50 to 100 mW·cm−2 . Moreover the enthalpy (∆H*) and entropy (∆S*) values of Cu/CuO electrode were determined as 9.519 KJ mol−1 and 180.4 JK−1 ·mol−1 respectively. The results obtained in the present study are very promising for solving the problem of energy in far regions by converting sewage water to H2 fuel.
Effect of Au Plasmonic Material on Poly M-Toluidine for Photoelectrochemical Hydrogen Generation from Sewage Water
Feb 2022
Publication
This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So this study has a dual benefit for hydrogen generation; at the same time it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min respectively. The complete analyses confirm the chemical structure such as XRD FTIR HNMR SEM and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm) and the number of H2 moles increases from 8.4 to 33.1 mmol h−1 cm−2 for using Na2S2O3 and sewage water as electrolyte respectively. Moreover all the thermodynamic parameters such as activation energy (Ea) enthalpy (∆H*) and entropy (∆S*) were calculated; additionally a simple mechanism is mentioned for the water-splitting reaction.
A Pathway to Decarbonise the Shipping Sector by 2050
Oct 2021
Publication
Urgent action is needed to accelerate the pace of the global energy transition and the decarbonisation of the global economy. International shipping is a key sector of the economy as much as 90% of worldwide trade is transacted via ocean going vessels. The sector is also one of the most challenging to decarbonise.
In this context A Pathway to Decarbonise the Shipping Sector by 2050 by the International Renewable Energy Agency (IRENA) analyses the technology readiness of the renewable fuels suitable for international shipping. This report also explores the options and actions needed to progress towards a decarbonised maritime shipping sector by 2050 and seeks to identify a realistic mitigation pathway to reach the climate goal of limiting global temperature rise to 1.5°C and bringing CO2 emissions closer to net zero by mid-century.
Key messages:
In this context A Pathway to Decarbonise the Shipping Sector by 2050 by the International Renewable Energy Agency (IRENA) analyses the technology readiness of the renewable fuels suitable for international shipping. This report also explores the options and actions needed to progress towards a decarbonised maritime shipping sector by 2050 and seeks to identify a realistic mitigation pathway to reach the climate goal of limiting global temperature rise to 1.5°C and bringing CO2 emissions closer to net zero by mid-century.
Key messages:
- The sector’s decarbonisation strategy must involve a combination of energy efficiency and renewable fuels. Starting now the active adoption of energy efficiency measures will be critical to reduce energy demand and thus CO2 emissions in the immediate term.
- In the short term advanced biofuels will play a key role in the reduction of CO2 emissions. In the medium and long-term green hydrogen-based fuels are set to be the backbone for the sector’s decarbonisation.
- Renewable e-ammonia will play a pivotal role; where 183 million tonnes of renewable ammonia for international shipping alone will be needed by 2050 - a comparable amount to today’s ammonia global production.
- While renewable fuels production costs are currently high in the next decades renewable fuels will become cost competitive and can shield the shipping sector from the volatility that characterises the fossil fuels market.
- Taking early action is vital. Sector decarbonisation can be accelerated and ambition raised beyond the climate goals by fostering investment in the production of renewable fuels. Stakeholders need to develop broader business models and establish strategic partnerships involving energy-intensive industries as well as power suppliers and the petrochemical sector.
Hydrogen Effect on the Cyclic Behavior of a Superelastic NiTi Archwire
Mar 2019
Publication
In this work we are interested in examining the strain rate effect on the mechanical behavior of Ni–Ti superelastic wires after hydrogen charging and ageing for 24 h. Specimens underwent 50 cycles of loading-unloading reaching an imposed deformation of 7.6%. During loading strain rates from 10−4 s−1 to 10−2 s−1 were achieved. With a strain rate of 10−2 s−1 the specimens were charged by hydrogen for 6 h and aged for one day showed a superelastic behavior marked by an increase in the residual deformation as a function of the number of cycles. In contrast after a few number of cycles with a strain rate of 10−4 s−1 the Ni-Ti alloy archwire specimens fractured in a brittle manner during the martensite transformation stage. The thermal desorption analysis showed that for immersed specimens the desorption peak of hydrogen appeared at 320 °C. However after annealing the charged specimens by hydrogen at 400 °C for 1 h an embrittlement took place at the last cycles for the lower strain rates of 10−4 s−1. The present study suggests that the embrittlement can be due to the development of an internal stress in the subsurface of the parent phase during hydrogen charging and due to the creation of cracks and local zones of plasticity after desorption.
Recent Advances in Biomass Pretreatment Technologies for Biohydrogen Production
Jan 2022
Publication
Hydrogen is an economical source of clean energy that has been utilized by industry for decades. In recent years demand for hydrogen has risen significantly. Hydrogen sources include water electrolysis hydrocarbon steam reforming and fossil fuels which emit hazardous greenhouse gases and therefore have a negative impact on global warming. The increasing worldwide population has created much pressure on natural fuels with a growing gap between demand for renewable energy and its insufficient supply. As a result the environment has suffered from alarming increases in pollution levels. Biohydrogen is a sustainable energy form and a preferable substitute for fossil fuel. Anaerobic fermentation photo fermentation microbial and enzymatic photolysis or combinations of such techniques are new approaches for producing biohydrogen. For cost-effective biohydrogen production the substrate should be cheap and renewable. Substrates including algal biomass agriculture residue and wastewaters are readily available. Moreover substrates rich in starch and cellulose such as plant stalks or agricultural waste or food industry waste such as cheese whey are reported to support dark- and photo-fermentation. However their direct utilization as a substrate is not recommended due to their complex nature. Therefore they must be pretreated before use to release fermentable sugars. Various pretreatment technologies have been established and are still being developed. This article focuses on pretreatment techniques for biohydrogen production and discusses their efficiency and suitability including hybrid-treatment technology
A Review on Underground Hydrogen Storage: Insight into Geological Sites, Influencing Factors and Future Outlook
Dec 2021
Publication
Without remorse fossil fuels have made a huge contribution to global development in all of its forms. However the recent scientific outlooks are currently shifting as more research is targeted towards promoting a carbon-free economy in addition to the use of electric power from renewable sources. While renewable energy sources may be a solution to the anthropogenic greenhouse gas (GHG) emissions from fossil fuel they are yet season-dependent faced with major atmospheric drawbacks which when combined with annually varying but steady energy demand results in renewable energy excesses or deficits. Therefore it is essential to devise a long-term storage medium to balance their intermittent demand and supply. Hydrogen (H2) as an energy vector has been suggested as a viable method of achieving the objectives of meeting the increasing global energy demand. However successful implementation of a full-scale H2 economy requires large-scale H2 storage (as H2 is highly compressible). As such storage of H2 in geological formations has been considered as a potential solution where it can be withdrawn again at the larger stage for utilization. Thus in this review we focus on the potential use of geological formations for large-scale underground hydrogen storage (UHS) where both conventional and non-conventional UHS options were examined in depth. Also insights into some of the probable sites and the related examined criteria for selection were highlighted. The hydrodynamics of UHS influencing factors (including solid fluid and solid–fluid interactions) are summarized exclusively. In addition the economics and reaction perspectives inherent to UHS have been examined. The findings of this study show that UHS like other storage systems is still in its infancy. Further research and development are needed to address the significant hurdles and research gaps found particularly in replaceable influencing parameters. As a result this study is a valuable resource for UHS researchers.
Geopolitics of the Energy Transformation: The Hydrogen Factor
Jan 2022
Publication
As countries around the world rally behind net zero targets hydrogen is increasingly seen as a missing piece of the energy transformation puzzle to decarbonise harder-to-abate sectors. The possible pathway on which hydrogen might evolve still involves many uncertainties. With the growing momentum to establish a global hydrogen market comes the need for a deeper understanding of its broader effects including geopolitical aspects. IRENA has carried out an in-depth analysis of the geopolitics of hydrogen as part of the work of the Collaborative Framework on the Geopolitics of Energy Transformation (CF-GET). The report builds on IRENA’s substantial body of work in hydrogen and benefits from a wide range of expert input in the fields of energy and geopolitics.
This report considers whether and how hydrogen may disrupt future energy systems reflecting on many of the key themes discussed in the Global Commission’s report A New World – The Geopolitics of the Energy Transformation. The analysis offers insights into how countries and stakeholders can navigate the uncertainties and shape the development of hydrogen markets and outlines policy considerations to help mitigate the geopolitical risks and capitalise on opportunities. Some of the key findings of the report include:
This report considers whether and how hydrogen may disrupt future energy systems reflecting on many of the key themes discussed in the Global Commission’s report A New World – The Geopolitics of the Energy Transformation. The analysis offers insights into how countries and stakeholders can navigate the uncertainties and shape the development of hydrogen markets and outlines policy considerations to help mitigate the geopolitical risks and capitalise on opportunities. Some of the key findings of the report include:
- Hydrogen is part of a much bigger energy transition picture and its development and deployment strategies should not be considered in isolation.
- Setting the right priorities for hydrogen use will be essential for its rapid scale-up and long-term contribution to decarbonisation efforts.
- The 2020s could become the era of a big race for technology leadership as costs are likely to fall sharply with learning and scaling-up of needed infrastructure. Equipment manufacturing offers an opportunity to capture value in the coming years and decades.
- Hydrogen trade and investment flows will spawn new patterns of interdependence and bring shifts in bilateral relations.
- Countries with an abundance of low-cost renewable power could become producers of green hydrogen with commensurate geoeconomic and geopolitical consequences.
- Hydrogen could be an attractive avenue for fossil fuel exporters to help diversify their economies and develop new export industries.
- Supporting the advancement of renewable energy and green hydrogen in developing countries is critical for decarbonising the energy system and can contribute to global equity and stability.
- International co-operation will be necessary to devise a transparent hydrogen market with coherent standards and norms that contribute to climate change efforts meaningfully.
A Thorough Economic Evaluation by Implementing Solar/Wind Energies for Hydrogen Production: A Case Study
Jan 2022
Publication
A technical–economic assessment was carried out in this study to determine the possibilities for wind and solar power generation in Afghanistan’s Helmand province. The results showed that most of the province has a solar irradiance of over 400 W/m2 and also showed that wind and solar power generated in the province can be up to twice as cheap as the official price of renewable power in Afghanistan. The most suitable site for solar and hydrogen production was found to be Laškar Gah where solar and hydrogen can be produced at a cost of 0.066 $/kWh and 2.1496 $/kg-H ¯ 2 respectively. In terms of wind power production and hydrogen production from wind the most suitable site was Sang¯ın where wind power and hydrogen could be produced at costs of 0.057 $/kWh and 1.4527 $/kg-H2 respectively. Despite the high potential of wind and solar energy in the Helmand province the most suitable place in this region to produce hydrogen from wind/solar energy was evaluated from technical economic and environmental perspectives with the Multi-Criteria DecisionMaking (MCDM) method. The Stepwise Weight Assessment Ratio Analysis (SWARA) method was used for weighting criteria and the Weighted Aggregated Sum Product Assessment (WASPAS) method was used to prioritize locations. The results show that Sang¯ın is the most suitable place for the construction of a wind hydrogen power plant and Laškar Gah is the most suitable place for the ¯ construction of a solar hydrogen power plant.
TM-doped Mg12O12 Nano-cages for Hydrogen Storage Applications: Theoretical Study
Feb 2022
Publication
DFT calculations at B3LYP/6-31g(dp) with the D3 version of Grimme’s dispersion are performed to investigate the application of TM-encapsulated Mg12O12 nano-cages (TM= Mn Fe and Co) as a hydrogen storage material. The molecular dynamic (MD) calculations are utilized to examine the stability of the considered structures. TD-DFT method reveals that the TM-encapsulation converts the Mg12O12 from an ultraviolet into a visible optical active material. The adsorption energy values indicate that the Mn and Fe atoms encapsulation enhances the adsorption of H2 molecules on the Mg12O12 nano-cage. The pristine Mg12O12 and CoMg12O12 do not meet the requirements for hydrogen storage materials while the MnMg12O12 and FeMg12O12 obey the requirements. MnMg12O12 and FeMg12O12 can carry up to twelve and nine H2 molecules respectively. The hydrogen adsorption causes a redshift for the λmax value of the UV-Vis. spectra of the MnMg12O12 and FeMg12O12 nano-cages. The thermodynamic calculations show that the hydrogen storage reaction for MnMg12O12 nano-cage is a spontaneous reaction while for FeMg12O12 nano-cage is not spontaneous. The results suggested that the MnMg12O12 nano-cage may be a promising material for hydrogen storage applications.
A Developed Plasmatron Design to Enhance Production of Hydrogen in Synthesis Gas Produced by a Fuel Reformer System
Jan 2022
Publication
Feeding IC engines with hydrogen‐rich syngas as an admixture to hydrocarbon fuels can decrease pollutant emissions particularly NOx. It offers a potential technique for low‐environmen‐ tal impact hydrocarbon fuel use in automotive applications. However hydrogen‐rich reformate gas (syngas) production via fuel reforming still needs more research and optimization. In this paper we describe the effect of a plasma torch assembly design on syngas yield and composition during plasma‐assisted reforming of gasoline. Additionally erosion resistance of the cathode‐emitting ma‐ terial under the conditions of gasoline reforming was studied using hafnium metal and lanthanated tungsten alloy. The gasoline reforming was performed with a noncatalytic nonthermal low‐current plasma system in the conditions of partial oxidation in an air and steam mixture. To find the most efficient plasma torch assembly configuration in terms of hydrogen production yield four types of anode design were tested i.e. two types of the swirl ring and two cathode materials while varying the inlet air and fuel flow rates. The experimental results showed that hydrogen was the highest proportion of the produced syngas. The smooth funnel shape anode design in Ring 1 at air/fuel flow rates of 24/4 27/4.5 and 30/5 g/min respectively was more effective than the edged funnel shape. Lanthanated tungsten alloy displayed higher erosion resistance than hafnium metal.
Clean Hydrogen Production by Ultrasound (Sonochemistry): The Effect of Noble Gases
Feb 2022
Publication
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.
A Process for Hydrogen Production from the Catalytic Decomposition of Formic Acid over Iridium—Palladium Nanoparticles
Jun 2021
Publication
The present study investigates a process for the selective production of hydrogen from the catalytic decomposition of formic acid in the presence of iridium and iridium–palladium nanoparticles under various conditions. It was found that a loading of 1 wt.% of 2% palladium in the presence of 1% iridium over activated charcoal led to a 43% conversion of formic acid to hydrogen at room temperature after 4 h. Increasing the temperature to 60 °C led to further decomposition and an improvement in conversion yield to 63%. Dilution of formic acid from 0.5 to 0.2 M improved the decomposition reaching conversion to 81%. The reported process could potentially be used in commercial applications.
Hydrogen Diffusion in Coal: Implications for Hydrogen Geo-storage
Oct 2021
Publication
Hypothesis: Hydrogen geo-storage is considered as an option for large scale hydrogen storage in a full-scale hydrogen economy. Among different types of subsurface formations coal seams look to be one of the best suitable options as coal’s micro/nano pore structure can adsorb a huge amount of gas (e.g. hydrogen) which can be withdrawn again once needed. However literature lacks fundamental data regarding H2 diffusion in coal. Experiments: In this study we measured H2 adsorption rate in an Australian anthracite coal sample at isothermal conditions for four different temperatures (20 C 30 C 45 C and 60 C) at equilibrium pressure 13 bar and calculated H2 diffusion coefficient (DH2 ) at each temperature. CO2 adsorption rates were measured for the same sample at similar temperatures and equilibrium pressure for comparison. Findings: Results show that H2 adsorption rate and consequently DH2 increases by temperature. DH2 values are one order of magnitude larger than the equivalent DCO2 values for the whole studied temperature range 20–60 C. DH2 / DCO2 also shows an increasing trend versus temperature. CO2 adsorption capacity at equilibrium pressure is about 5 times higher than that of H2 in all studied temperatures. Both H2 and CO2 adsorption capacities at equilibrium pressure slightly decrease as temperature rises.
Influence of Pressure, Temperature and Organic Surface Concentration on Hydrogen Wettability of Caprock; Implications for Hydrogen Geo-storage
Sep 2021
Publication
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.
Ranking Locations for Hydrogen Production Using Hybrid Wind-Solar: A Case Study
Apr 2021
Publication
Observing the growing energy demand of modern societies many countries have recognized energy security as a looming problem and renewable energies as a solution to this issue. Renewable hydrogen production is an excellent method for the storage and transfer of energy generated by intermittent renewable sources such as wind and solar so that they can be used at a place and time of our choosing. In this study the suitability of 15 cities in Fars province Iran for renewable hydrogen production was investigated and compared by the use of multiple multi-criteria decision-making methods including ARAS SAW CODAS and TOPSIS. The obtained rankings were aggregated by rank averaging Borda method and Copeland method. Finally the partially ordered set ranking technique was used to reach a general consensus about the ranking. The criteria that affect hydrogen production were found to be solar energy potential wind energy potential population air temperature natural disasters altitude relative humidity land cost skilled labor infrastructure topographic condition and distance from main roads. These criteria were weighted using the best–worst method (BWM) based on the data collected by a questionnaire. Solar energy potential was estimated using the Angstrom model. Wind energy potential was estimated by using the Weibull distribution function for each month independently. The results of the multi-criteria decision-making methods showed Izadkhast to be the most suitable location for renewable hydrogen production in the studied area.
A Critical Review of Renewable Hydrogen Production Methods: Factors Affecting Their Scale-Up and Its Role in Future Energy Generation
Feb 2022
Publication
An increase in human activities and population growth have significantly increased the world’s energy demands. The major source of energy for the world today is from fossil fuels which are polluting and degrading the environment due to the emission of greenhouse gases. Hydrogen is an identified efficient energy carrier and can be obtained through renewable and non-renewable sources. An overview of renewable sources of hydrogen production which focuses on water splitting (electrolysis thermolysis and photolysis) and biomass (biological and thermochemical) mechanisms is presented in this study. The limitations associated with these mechanisms are discussed. The study also looks at some critical factors that hinders the scaling up of the hydrogen economy globally. Key among these factors are issues relating to the absence of a value chain for clean hydrogen storage and transportation of hydrogen high cost of production lack of international standards and risks in investment. The study ends with some future research recommendations for researchers to help enhance the technical efficiencies of some production mechanisms and policy direction to governments to reduce investment risks in the sector to scale the hydrogen economy up.
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