Saudi Arabia
Techno-Economic Evaluation of Hydrogen Production via Gasification of Vacuum Residue Integrated with Dry Methane Reforming
Dec 2021
Publication
The continuous rise of global carbon emissions demands the utilization of fossil fuels in a sustainable way. Owing to various forms of emissions our environment conditions might be affected necessitating more focus of scientists and researchers to upgrade oil processing to more efficient manner. Gasification is a potential technology that can convert fossil fuels to produce clean and environmentally friendly hydrogen fuel in an economical manner. Therefore this study analyzed and examined it critically. In this study two different routes for the production of high-purity hydrogen from vacuum residue while minimizing the carbon emissions were proposed. The first route (Case I) studied the gasification of heavy vacuum residue (VR) in series with dry methane reforming (DMR). The second route studied the gasification of VR in parallel integration with DMR (Case II). After investigating both processes a brief comparison was made between the two routes of hydrogen production in terms of their CO2 emissions energy efficiency energy consumption and environmental and economic impacts. In this study the two vacuum-residue-to-hydrogen (VRTH) processes were simulated using Aspen Plus for a hydrogen production capacity of 50 t/h with 99.9 wt.% purity. The results showed that Case II offered a process energy efficiency of 57.8% which was slightly higher than that of Case I. The unit cost of the hydrogen product for Case II was USD 15.95 per metric ton of hydrogen which was almost 9% lower than that of Case I. In terms of the environmental analysis both cases had comparably low carbon emissions of around 8.3 kg of CO2/kg of hydrogen produced; with such high purity the hydrogen could be used for production of other products further downstream or for industrial applications.
Numerical Study on Hydrogen–Gasoline Dual-Fuel Spark Ignition Engine
Nov 2022
Publication
Hydrogen as a suitable and clean energy carrier has been long considered a primary fuel or in combination with other conventional fuels such as gasoline and diesel. Since the density of hydrogen is very low in port fuel-injection configuration the engine’s volumetric efficiency reduces due to the replacement of hydrogen by intake air. Therefore hydrogen direct in-cylinder injection (injection after the intake valve closes) can be a suitable solution for hydrogen utilization in spark ignition (SI) engines. In this study the effects of hydrogen direct injection with different hydrogen energy shares (HES) on the performance and emissions characteristics of a gasoline port-injection SI engine are investigated based on reactive computational fluid dynamics. Three different injection timings of hydrogen together with five different HES are applied at low and full load on a hydrogen– gasoline dual-fuel SI engine. The results show that retarded hydrogen injection timing increases the concentration of hydrogen near the spark plug resulting in areas with higher average temperatures which led to NOX emission deterioration at −120 Crank angle degree After Top Dead Center (CAD aTDC) start of injection (SOI) compared to the other modes. At −120 CAD aTDC SOI for 50% HES the amount of NOX was 26% higher than −140 CAD aTDC SOI. In the meanwhile an advanced hydrogen injection timing formed a homogeneous mixture of hydrogen which decreased the HC and soot concentration so that −140 CAD aTDC SOI implied the lowest amount of HC and soot. Moreover with the increase in the amount of HES the concentrations of CO CO2 and soot were reduced. Having the HES by 50% at −140 CAD aTDC SOI the concentrations of particulate matter (PM) CO and CO2 were reduced by 96.3% 90% and 46% respectively. However due to more complete combustion and an elevated combustion average temperature the amount of NOX emission increased drastically.
Hybrid Electric Vehicle: Design and Control of a Hybrid System (Fuel Cell/Battery/Ultra-Capacitor) Supplied by Hydrogen
Apr 2019
Publication
Due to its high efficiency and reduced emissions new zero-emission hybrid electric vehicles have been selected as an attractive challenge for future transport applications. New zero -emission hybrid electric on the other hand has some major drawbacks from the complicated charging process. The hybrid electrical fuel cell system is introduced as the main source to intelligently control multi-source activities. An ultra-capacitor system is selected as the energy recovery assistance to monitor the fuel cell’s fast transient and peak power during critical periods. To regulate energy demand and supply an intelligent energy management system is proposed and tested through several constraints. The proposed approach system aims to act quickly against sudden circumstances related to hydrogen depletion in the prediction of the required fuel consumption basis. The proposed strategy tends to define the proper operating system according to energy demand and supply. The obtained results show that the designed system meets the targets set for the energy management unit by referring to an experimental velocity database.
Hydrogen Production by Solar Thermochemical Water-Splitting Cycle via a Beam Down Concentrator
May 2021
Publication
About 95% of the hydrogen presently produced is from natural gas and coal and the remaining 5% is generated as a by-product from the production of chlorine through electrolysis1 . In the hydrogen economy (Crabtree et al. 2004; Penner 2006; Marbán and Valdés-Solís 2007) hydrogen is produced entirely from renewable energy. The easiest approach to advance renewable energy production is through solar photovoltaic and electrolysis a pathway of high technology readiness level (TRL) suffering however from two downfalls. First of all electricity is already an energy carrier and transformation with a penalty into another energy carrier hydrogen is in principle flawed. The second problem is that the efficiency of commercial solar panels is relatively low. The cadmium telluride (CdTe) thin-film solar cells have a solar energy conversion efficiency of 17%. Production of hydrogen using the current best processes for water electrolysis has an efficiency of ∼70%. As here explained the concentrated solar energy may be used to produce hydrogen using thermochemical water-splitting cycles at much global higher efficiency (fuel energy to incident sun energy). This research and development (R&D) effort is therefore undertaken to increase the TRL of this approach as a viable and economical option.
Greenhouse Gas Emission Dynamics of Saudi Arabia: Potential of Hydrogen Fuel for Emission Footprint Reduction
Mar 2023
Publication
The growth of population gross domestic product (GDP) and urbanization have led to an increase in greenhouse gas (GHG) emissions in the Kingdom of Saudi Arabia (KSA). The leading GHG-emitting sectors are electricity generation road transportation cement chemicals refinery iron and steel. However the KSA is working to lead the global energy sustainability campaign to reach net zero GHG emissions by 2060. In addition the country is working to establish a framework for the circular carbon economy (CCE) in which hydrogen acts as a transversal facilitator. To cut down on greenhouse gas emissions the Kingdom is also building several facilities such as the NEOM green hydrogen project. The main objective of the article is to critically review the current GHG emission dynamics of the KSA including major GHG emission driving forces and prominent emission sectors. Then the role of hydrogen in GHG emission reduction will be explored. Finally the researchers and decision makers will find the helpful discussions and recommendations in deciding on appropriate mitigation measures and technologies.
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.
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.
Techno-Economic Analysis of the Hybrid Solar PV/H/Fuel Cell Based Supply Scheme for Green Mobile Communication
Nov 2021
Publication
Hydrogen has received tremendous global attention as an energy carrier and an energy storage system. Hydrogen carrier introduces a power to hydrogen (P2H) and power to hydrogen to power (P2H2P) facility to store the excess energy in renewable energy storage systems with the facts of large-scale storage capacity transportability and multiple utilities. This work examines the techno-economic feasibility of hybrid solar photovoltaic (PV)/hydrogen/fuel cell-powered cellular base stations for developing green mobile communication to decrease environmental degradation and mitigate fossil-fuel crises. Extensive simulation is carried out using a hybrid optimization model for electric renewables (HOMER) optimization tool to evaluate the optimal size energy production total production cost per unit energy production cost and emission of carbon footprints subject to different relevant system parameters. In addition the throughput and energy efficiency performance of the wireless network is critically evaluated with the help of MATLAB-based Monte-Carlo simulations taking multipath fading system bandwidth transmission power and inter-cell interference (ICI) into consideration. Results show that a more stable and reliable green solution for the telecommunications sector will be the macro cellular basis stations driven by the recommended hybrid supply system. The hybrid supply system has around 17% surplus electricity and 48.1 h backup capacity that increases the system reliability by maintaining a better quality of service (QoS). To end the outcomes of the suggested system are compared with the other supply scheme and the previously published research work for justifying the validity of the proposed system.
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.
Hydrogen Double Compression-expansion Engine (H2DCEE): A Sustainable Internal Combustion Engine with 60%+ Brake Thermal Efficiency Potential at 45 Bar BMEP
May 2022
Publication
Hydrogen (H2) internal combustion engines may represent cost-effective and quick solution to the issue of the road transport decarbonization. A major factor limiting their competitiveness relative to fuel cells (FC) is the lower efficiency. The present work aims to demonstrate the feasibility of a H2 engine with FC-like 60%+ brake thermal efficiency (BTE) levels using a double compression-expansion engine (DCEE) concept combined with a high pressure direct injection (HPDI) nonpremixed H2 combustion. Experimentally validated 3D CFD simulations are combined with 1D GT-Power simulations to make the predictions. Several modifications to the system design and operating conditions are systematically implemented and their effects are investigated. Addition of a catalytic burner in the combustor exhaust insulation of the expander dehumidification of the EGR and removal of the intercooling yielded 1.5 1.3 0.8 and 0.5%-point BTE improvements respectively. Raising the peak pressure to 300 bar via a larger compressor further improved the BTE by 1.8%-points but should be accompanied with a higher injector-cylinder differential pressure. The λ of ~1.4 gave the optimum tradeoff between the mechanical and combustion efficiencies. A peak BTE of 60.3% is reported with H2DCEE which is ~5%-points higher than the best diesel-fueled DCEE alternative.
An Insight into Carbon Nanomaterial-Based Photocatalytic Water Splitting for Green Hydrogen Production
Dec 2022
Publication
At present the energy shortage and environmental pollution are the burning global issues. For centuries fossil fuels have been used to meet worldwide energy demand. However thousands of tons of greenhouse gases are released into the atmosphere when fossil fuels are burned contributing to global warming. Therefore green energy must replace fossil fuels and hydrogen is a prime choice. Photocatalytic water splitting (PWS) under solar irradiation could address energy and environmental problems. In the past decade solar photocatalysts have been used to manufacture sustainable fuels. Scientists are working to synthesize a reliable affordable and light-efficient photocatalyst. Developing efficient photocatalysts for water redox reactions in suspension is a key to solar energy conversion. Semiconductor nanoparticles can be used as photocatalysts to accelerate redox reactions to generate chemical fuel or electricity. Carbon materials are substantial photocatalysts for total WS under solar irradiation due to their high activity high stability low cost easy production and structural diversity. Carbon-based materials such as graphene graphene oxide graphitic carbon nitride fullerenes carbon nanotubes and carbon quantum dots can be used as semiconductors photosensitizers cocatalysts and support materials. This review comprehensively explains how carbon-based composite materials function as photocatalytic semiconductors for hydrogen production the water-splitting mechanism and the chemistry of redox reactions. Also how heteroatom doping defects and surface functionalities etc. can influence the efficiency of carbon photocatalysts in H2 production. The challenges faced in the PWS process and future prospects are briefly discussed.
Portable Prototype of Hydrogen Fuel Cells for Educational Training
Jan 2023
Publication
This paper presents an experimental prototype of hydrogen fuel cells suitable for training engineering students. The presented system is designed to teach students the V-I characteristics of the fuel cells and how to record the V-I characteristics curve in the case of a single or multiple fuel cells. The prototype contains a compact electrolyzer to produce hydrogen and oxygen to the fuel cell. The fuel cell generates electricity to supply power to various types of loads. The paper also illustrates how to calculate the efficiency of fuel cells in series and parallel modes of operation. In the series mode of operation it is mathematically proven that the efficiency is higher at lower currents. Still the fuel cell operating area is required where the power is the highest. According to experimental results the efficiency in the case of series connection is approximately 25% while in parallel operation mode the efficiency is about 50%. Thus a parallel connection is recommended in the high current applications because the efficiency is higher than the one resulted from series connection. As explained later in the study plan several other experiments can be performed using this educational kit.
A Review of Hydrogen Production and Supply Chain Modeling and Optmization
Jan 2023
Publication
This paper reviews recent optimization models for hydrogen supply chains and production. Optimization is a central component of systematic methodologies to support hydrogen expansion. Hydrogen production is expected to evolve in the coming years to help replace fossil fuels; these high expectations arise from the potential to produce low-carbon hydrogen via electrolysis using electricity generated by renewable sources. However hydrogen is currently mainly used in refinery and industrial operations; therefore physical infrastructures for transmission distribution integration with other energy systems and efficient hydrogen production processes are lacking. Given the potential of hydrogen the greenfield state of infrastructures and the variability of renewable sources systematic methodologies are needed to reach competitive hydrogen prices and design hydrogen supply chains. Future research topics are identified: 1) improved hydrogen demand projections 2) integrated sector modeling 3) improving temporal and spatial resolutions 4) accounting for climate change 5) new methods to address sophisticated models.
Demonstration of Green Hydrogen Production Using Solar Energy at 28% Efficiency and Evaluation of its Economic Viability
Jan 2021
Publication
The solar to hydrogen (STH) efficiency of photovoltaic-electrolysis (PV-E) setups is a key parameter to lower the cost of green hydrogen produced. Commercial c-Si solar cells have neared saturation with respect to their efficiency which warrants the need to look at alternative technologies. In this work we report a concentrator photovoltaic-electrolysis (CPV-E) setup with a STH efficiency of 28% at 41 suns (without the use of Fresnel lenses) the highest reported efficiency using an alkaline system to date. Using this as a base case we carried out a detailed techno-economic (TEA) analysis which showed that despite the high cost associated with CPV cells the levelized cost of hydrogen (LCOH) is at $5.9 kg1 close to that from c-Si solar farms ($4.9 kg1 ) primarily due to the high STH efficiency. We also report sensitivity analysis of factors affecting both CPV and alkaline electrolyser systems such as the CPV module efficiency and installed capacity electrolyser stack lifetime operating current density and working hours. Our results indicate that in a scenario where the installed capacity of CPV technology matches that of silicon and with an electrolyser operating current density of 0.7 A cm2 the LCOH from CPV electrolysis systems can be.
A Review on Hydrogen-Based Hybrid Microgrid System: Topologies for Hydrogen Energy Storage, Integration, and Energy Management with Solar and Wind Energy
Oct 2022
Publication
Hydrogen is acknowledged as a potential and appealing energy carrier for decarbonizing the sectors that contribute to global warming such as power generation industries and transportation. Many people are interested in employing low-carbon sources of energy to produce hydrogen by using water electrolysis. Additionally the intermittency of renewable energy supplies such as wind and solar makes electricity generation less predictable potentially leading to power network incompatibilities. Hence hydrogen generation and storage can offer a solution by enhancing system flexibility. Hydrogen saved as compressed gas could be turned back into energy or utilized as a feedstock for manufacturing building heating and automobile fuel. This work identified many hydrogen production strategies storage methods and energy management strategies in the hybrid microgrid (HMG). This paper discusses a case study of a HMG system that uses hydrogen as one of the main energy sources together with a solar panel and wind turbine (WT). The bidirectional AC-DC converter (BAC) is designed for HMGs to maintain power and voltage balance between the DC and AC grids. This study offers a control approach based on an analysis of the BAC’s main circuit that not only accomplishes the function of bidirectional power conversion but also facilitates smooth renewable energy integration. While implementing the hydrogen-based HMG the developed control technique reduces the reactive power in linear and non-linear (NL) loads by 90.3% and 89.4%.
Hydrogen Balloon Transportation: A Cheap and Efficiency Mode to Transport Hydrogen
Nov 2023
Publication
The chances of a global hydrogen economy becoming a reality have increased significantly since the COVID pandemic and the war in Ukraine and for net zero carbon emissions. However intercontinental hydrogen transport is still a major issue. This study suggests transporting hydrogen as a gas at atmospheric pressure in balloons using the natural flow of wind to carry the balloon to its destination. We investigate the average wind speeds atmospheric pressure and temperature at different altitudes for this purpose. The ideal altitudes to transport hydrogen with balloons are 10 km or lower and hydrogen pressures in the balloon vary from 0.25 to 1 bar. Transporting hydrogen from North America to Europe at a maximum 4 km altitude would take around 4.8 days on average. Hydrogen balloon transportation cost is estimated at 0.08 USD/kg of hydrogen which is around 12 times smaller than the cost of transporting liquified hydrogen from the USA to Europe. Due to its reduced energy consumption and capital cost in some locations hydrogen balloon transportation might be a viable option for shipping hydrogen compared to liquefied hydrogen and other transport technologies.
An Estimation of Green Hydrogen Generation from Wind Energy: A Case Study from KSA
Sep 2023
Publication
Actually green hydrogen is viewed as a fundamental component in accelerating energy transition and empowering a sustainable future. The current study focuses on the estimation of green hydrogen generation by using wind energy via electrolysis in four sites located in Saudi Arabia. Results showed that the yearly amount of hydrogen that could be generated by using wind turbine ranges between 2542877 kg in Rafha and 3676925 kg in Dhahran. The hydrogen generated could be used to fuel vehicles and decrease the amount of GHG emission from vehicles in KSA. Also hydrogen may be used to store the excess of wind energy and to support the achievement of vision 2030 of the Kingdom. An economic assessment is carried out also in this paper. Results showed that the LCOH by using wind energy in KSA ranges from 2.82 $/kg to 3.81 $/kg.
An Overview on the Technologies Used to Storage Hydrogen
Aug 2023
Publication
Hydrogen energy has a significant potential in mitigating the intermittency of renewable energy generation by converting the excess of renewable energy into hydrogen through many technologies. Also hydrogen is expected to be used as an energy carrier that contribute to the global decarbonization in transportation industrial and building sectors. Many technologies have been developed to store hydrogen energy. Hydrogen can be stored to be used when needed and thus synchronize generation and consumption. The current paper presents a review on the different technologies used to store hydrogen. The storage capacity advantages drawbacks and development stages of various hydrogen storage technologies were presented and compared.
Advancing Hydrogen: A Closer Look at Implementation Factors, Current Status and Future Potential
Dec 2023
Publication
This review article provides a comprehensive analysis of the hydrogen landscape outlining the imperative for enhanced hydrogen production implementation and utilisation. It places the question of how to accelerate hydrogen adoption within the broader context of sustainable energy transitions and international commitments to reduce carbon emissions. It discusses influencing factors and policies for best practices in hydrogen energy application. Through an in-depth exploration of key factors affecting hydrogen implementation this study provides insights into the complex interplay of both technical and logistical factors. It also discusses the challenges of planning constructing infrastructure and overcoming geographical constraints in the transition to hydrogen-based energy systems. The drive to achieve net-zero carbon emissions is contingent on accelerating clean hydrogen development with blue and green hydrogen poised to complement traditional fuels. Public–private partnerships are emerging as catalysts for the commercialisation of hydrogen and fuel-cell technologies fostering hydrogen demonstration projects worldwide. The anticipated integration of clean hydrogen into various sectors in the coming years signifies its importance as a complementary energy source although specific applications across industries remain undefined. The paper provides a good reference on the gradual integration of hydrogen into the energy landscape marking a significant step forward toward a cleaner greener future.
Energy Futures and Green Hydrogen Production: Is Saudi Arabia Trend?
May 2023
Publication
This paper explores the potential for hydrogen energy to become a future trend in Saudi Arabia energy industry. With the emergence of hydrogen as a promising clean energy source there has been growing interest and investment in this area globally. This study investigated whether the country is likely to pursue this trend given its current energy mix and policies. A study was conducted to provide an overview of the global trends and best practices in hydrogen energy adoption and investment. The outcomes of the analysis show that the country current energy mix has the potential to produce green hydrogen energy. The evaluation of its readiness and potential obstacles for hydrogen energy adoption has been drowned and there are several challenges that need to be addressed. The study outcomes also conclude with policy implications and recommendations for the country energy industry.
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