Production & Supply Chain
Conceptual Design of an Offshore Hydrogen Platform
Feb 2024
Publication
Offshore green hydrogen emerges as a guiding light in the global pursuit of environmental sustainability and net-zero objectives. The burgeoning expansion of offshore wind power faces significant challenges in grid integration. This avenue towards generating offshore green hydrogen capitalises on its ecological advantages and substantial energy potential to efficiently channel offshore wind power for onshore energy demands. However a substantial research void exists in efficiently integrating offshore wind electricity and green hydrogen. Innovative designs of offshore hydrogen platforms present a promising solution to bridge the gap between offshore wind and hydrogen integration. Surprisingly there is a lack of commercially established offshore platforms dedicated to the hydrogen industry. However the wealth of knowledge from oil and gas platforms contributes valuable insights to hydrogen platform design. Diverging from the conventional decentralised hydrogen units catering to individual turbines this study firstly introduces a pioneering centralised Offshore Green Hydrogen Platform (OGHP) which seamlessly integrates modular production storage and offloading modulars. The modular design of facilitates scalability as wind capacity increases. Through a detailed case study centred around a 100-Megawatt floating wind farm the design process of offshore green hydrogen modulars and its floating sub-structure is elucidated. Stability analysis and hydrodynamic analysis are performed to ensure the safety of the OGHP under the operation conditions. The case study will enhance our understanding OGHP and its modularised components. The conceptual design of modular OGHP offers an alternative solution to ‘‘Power-to-X’’ for offshore renewable energy sector.
Techno-economic Analysis of the Effect of a Novel Price-based Control System on the Hydrogen Production of an Offshore 1.5 GW Wind-hydrogen System
Feb 2024
Publication
The cost of green hydrogen production is very dependent on the price of electricity. A control system that can schedule hydrogen production based on forecast wind speed and electricity price should therefore be advantageous for large-scale wind-hydrogen systems. This work presents a novel price-based control system integrated in a techno-economic analysis of hydrogen production from offshore wind. A polynomial regression model that predicts wind power production from wind speed input was developed and tested with real-world datasets from a 2.3 MW floating offshore wind turbine. This was combined with a mathematical model of a PEM electrolyzer and used to simulate hydrogen production. A novel price-based control system was developed to decide when the system should produce hydrogen and when it should sell electricity to the grid. The model and control system can be used in real-world wind-hydrogen systems and require only the forecast wind speed electricity price and selling price of hydrogen as inputs. 11 test scenarios based on 10 years of real-world wind speed and electricity price data are proposed and used to evaluate the effect the price-based control system has on the levelized cost of hydrogen (LCOH). Both current and future (2050) costs and technologies are used and the results show that the novel control system lowered the LCOH in all scenarios by 10–46%. The lowest LCOH achieved with current technology and costs was 6.04 $/kg H2. Using the most optimistic forecasts for technology improvements and cost reductions in 2050 the model estimated a LCOH of 0.96 $/kg H2 for a grid-connected offshore wind farm and onshore hydrogen production 0.82 $/kg H2 using grid electricity (onshore) and 4.96 $/kg H2 with an offgrid offshore wind-hydrogen system. When the electricity price from the period 2013–2022 was used on the 2050 scenarios the resulting LCOH was approximately twice as high.
Hydrogen from Waste Gasification
Feb 2024
Publication
Hydrogen is a versatile energy vector for a plethora of applications; nevertheless its production from waste/residues is often overlooked. Gasification and subsequent conversion of the raw synthesis gas to hydrogen are an attractive alternative to produce renewable hydrogen. In this paper recent developments in R&D on waste gasification (municipal solid waste tires plastic waste) are summarised and an overview about suitable gasification processes is given. A literature survey indicated that a broad span of hydrogen relates to productivity depending on the feedstock ranging from 15 to 300 g H2/kg of feedstock. Suitable gas treatment (upgrading and separation) is also covered presenting both direct and indirect (chemical looping) concepts. Hydrogen production via gasification offers a high productivity potential. However regulations like frame conditions or subsidies are necessary to bring the technology into the market.
Towards a Sustainable Future: Bio-hydrogen Production from Food Waste for Clean Energy Generation
Jan 2024
Publication
To address climate change energy security and waste management new sustainable energy sources must be developed. This study uses Aspen Plus software to extract bio-H2 from food waste with the goal of efficiency and environmental sustainability. Anaerobic digestion optimised to operate at 20-25°C and keep ammonia at 3% greatly boosted biogas production. The solvent [Emim][FAP] which is based on imidazolium had excellent performance in purifying biogas. It achieved a high level of methane purity while consuming a minimal amount of energy with a solvent flow rate of 13.415 m³/h. Moreover the utilization of higher temperatures (600-700°C) during the bio-H2 generation phase significantly enhanced both the amount and quality of hydrogen produced. Parametric and sensitivity assessments were methodically performed at every stage. This integrated method was practicable and environmentally friendly according to the economic assessment. H2 generation using steam reforming results in a TCC of 1.92×106 USD. The CO2 separation step has higher costs (TCC of 2.15×107 USD) due to ionic liquid washing and CO2 liquefaction. Compressor electricity consumption significantly impacts total operating cost (TOC) totaling 4.73×108 USD. showing its ability to reduce greenhouse gas emissions optimize resource utilization and promote energy sustainability. This study presents a sustainable energy solution that addresses climate and waste challenges.
Enhancing Waste-to-Energy and Hydrogen Production through Urban–Industrial Symbiosis: A Multi-Objective Optimisation Model Incorporating a Bayesian Best-Worst Method
Feb 2024
Publication
A surging demand for sustainable energy and the urgency to lower greenhouse gas emissions is driving industrial systems towards more eco-friendly and cost-effective models. Biogas from agricultural and municipal organic waste is gaining momentum as a renewable energy source. Concurrently the European Hydrogen Strategy focuses on green hydrogen for decarbonising the industrial and transportation sectors. This paper presents a multi-objective network design model for urban–industrial symbiosis incorporating anaerobic digestion cogeneration photovoltaic and hydrogen production technologies. Additionally a Bayesian best-worst method is used to evaluate the weights of the sustainability aspects by decision-makers integrating these into the mathematical model. The model optimises industrial plant locations considering economic environmental and social parameters including the net present value energy consumption and carbon footprint. The model’s functionalities are demonstrated through a real-world case study based in Emilia Romagna Italy. It is subject to sensitivity analysis to evaluate how changes in the inputs affect the outcomes and highlights feasible trade-offs through the exploration of the ϵ-constraint. The findings demonstrate that the model substantially boosts energy and hydrogen production. It is not only economically viable but also reduces the carbon footprint associated with fossil fuels and landfilling. Additionally it contributes to job creation. This research has significant implications with potential future studies intended to focus on system resilience plant location optimisation and sustainability assessment.
A Comparative Analysis of Different Hydrogen Production Methods and Their Environmental Impact
Nov 2023
Publication
This study emphasises the growing relevance of hydrogen as a green energy source in meeting the growing need for sustainable energy solutions. It foregrounds the importance of assessing the environmental consequences of hydrogen-generating processes for their long-term viability. The article compares several hydrogen production processes in terms of scalability costeffectiveness and technical improvements. It also investigates the environmental effects of each approach considering crucial elements such as greenhouse gas emissions water use land needs and waste creation. Different industrial techniques have distinct environmental consequences. While steam methane reforming is cost-effective and has a high production capacity it is coupled with large carbon emissions. Electrolysis a technology that uses renewable resources is appealing but requires a lot of energy. Thermochemical and biomass gasification processes show promise for long-term hydrogen generation but further technological advancement is required. The research investigates techniques for improving the environmental friendliness of hydrogen generation through the use of renewable energy sources. Its ultimate purpose is to offer readers a thorough awareness of the environmental effects of various hydrogen generation strategies allowing them to make educated judgements about ecologically friendly ways. It can ease the transition to a cleaner hydrogen-powered economy by considering both technological feasibility and environmental issues enabling a more ecologically conscious and climate-friendly energy landscape.
Global Land and Water Limits to Electrolytic Hydrogen Production Using Wind and Solar Resources
Sep 2023
Publication
Proposals for achieving net-zero emissions by 2050 include scaling-up electrolytic hydrogen production however this poses technical economic and environmental challenges. One such challenge is for policymakers to ensure a sustainable future for the environment including freshwater and land resources while facilitating low-carbon hydrogen production using renewable wind and solar energy. We establish a country-by-country reference scenario for hydrogen demand in 2050 and compare it with land and water availability. Our analysis highlights countries that will be constrained by domestic natural resources to achieve electrolytic hydrogen self-sufficiency in a net-zero target. Depending on land allocation for the installation of solar panels or wind turbines less than 50% of hydrogen demand in 2050 could be met through a local production without land or water scarcity. Our findings identify potential importers and exporters of hydrogen or conversely exporters or importers of industries that would rely on electrolytic hydrogen. The abundance of land and water resources in Southern and Central-East Africa West Africa South America Canada and Australia make these countries potential leaders in hydrogen export.
Recent Advancements of Polymeric Membranes in Anion Exchange Membrane Water Electrolyzer (AEMWE): A Critical Review
Apr 2023
Publication
The formation of green hydrogen from water electrolysis is one of the supreme methodologies for understanding the well-organized consumption of sporadic renewable energies and the carbon-free future. Among the different electrolysis techniques the evolving anion exchange membrane water electrolysis (AEMWE) shows the utmost promise for manufacturing green hydrogen in an inexpensive way. In the present review we establish the most current and noteworthy achievements of AEMWE which include the advancements in increasing the ionic conductivity and understanding the mechanism of degradation of AEM and the most important topics regarding the designing of the electrocatalyst. The crucial issues that affect the AEMWE behavior are highlighted and future constraints and openings are also discussed. Furthermore this review article provides the appreciated strategies for producing extremely dynamic and robust electrocatalysts and evolving the construction of AEMWE equipment.
Modeling Green Hydrogen Production Using Power-to-x: Saudi and German Contexts
Apr 2024
Publication
This study assesses the competitiveness of producing green hydrogen (H2) in Saudi Arabia and Germany using a power-to-carrier (P2X) model in PLEXOS for 2030 and beyond. The target amount of H2 to be produced serves as the only exogenous input allowing the model which runs on an hourly temporal resolution to endogenously optimize the electrolyzer technology (alkaline proton exchange membrane or solid oxide electrolyzer cell) the capacity of the electrolyzer to be built and the optimal carbon-free energy mix. Results suggest the overall investment needs in Saudi Arabia are approximately 25% lower than those for wind-based hydrogen production in Germany with the best-case scenario to produce 0.213 Mt of green H2 costing a net present value of $6.20 billion in Saudi Arabia compared to $8.11 billion in Germany. The findings indicate that alkaline electrolyzers dominate the production process favored for their low cost despite the higher efficiencies of other electrolyzer types. Moreover the model opts to dump excess energy rather than construct battery storage. Based on 16 scenarios the study determines a levelized cost of hydrogen of 2.34–3.08 $/kg for Saudi Arabia compared with 3.06–3.69 $/kg in Germany. Subsequently a detailed sensitivity analysis considers various discount rates for both countries. It is concluded that even when considering shipment costs from Saudi Arabia to Germany (~1 $/kg) green H2 can still be competitively delivered from Saudi Arabia to Germany.
Hydrogen Production by Methane Pyrolysis in Molten Binary Copper Alloys
Sep 2023
Publication
The utilization of hydrogen as an energy carrier and reduction agent in important industrial sectors is considered a key parameter on the way to a sustainable future. Steam reforming of methane is currently the most industrially used process to produce hydrogen. One major drawback of this method is the simultaneous generation of carbon dioxide. Methane pyrolysis represents a viable alternative as the basic reaction produces no CO2 but solid carbon besides hydrogen. The aim of this study is the investigation of different molten copper alloys regarding their efficiency as catalytic media for the pyrolysis of methane in an inductively heated bubble column reactor. The conducted experiments demonstrate a strong influence of the catalyst in use on the one hand on the conversion rate of methane and on the other hand on the properties of the produced carbon. Optimization of these parameters is of crucial importance to achieve the economic competitiveness of the process.
Prediction of Transient Hydrogen Flow of Proton Exchange Membrane Electrolyzer Using Artificial Neural Network
Aug 2023
Publication
A proton exchange membrane (PEM) electrolyzer is fed with water and powered by electric power to electrochemically produce hydrogen at low operating temperatures and emits oxygen as a by-product. Due to the complex nature of the performance of PEM electrolyzers the application of an artificial neural network (ANN) is capable of predicting its dynamic characteristics. A handful of studies have examined and explored ANN in the prediction of the transient characteristics of PEM electrolyzers. This research explores the estimation of the transient behavior of a PEM electrolyzer stack under various operational conditions. Input variables in this study include stack current oxygen pressure hydrogen pressure and stack temperature. ANN models using three differing learning algorithms and time delay structures estimated the hydrogen mass flow rate which had transient behavior from 0 to 1 kg/h and forecasted better with a higher count (>5) of hidden layer neurons. A coefficient of determination of 0.84 and a mean squared error of less than 0.005 were recorded. The best-fitting model to predict the dynamic behavior of the hydrogen mass flow rate was an ANN model using the Levenberg–Marquardt algorithm with 40 neurons that had a coefficient of determination of 0.90 and a mean squared error of 0.00337. In conclusion optimally fit models of hydrogen flow from PEM electrolyzers utilizing artificial neural networks were developed. Such models are useful in establishing an agile flow control system for the electrolyzer system to help decrease power consumption and increase efficiency in hydrogen generation.
Socio-environmental and Technical Factors Assessment of Photovoltaic Hydrogen Production in Antofagasta, Chile
Apr 2024
Publication
This study introduces a method for identifying territories ideal for establishing photovoltaic (PV) plants for green hydrogen (GH2 ) production in the Antofagasta region of northern Chile a location celebrated for its outstanding solar energy potential. Assessing the viability of PV plant installation necessitates a balanced consideration of technical aspects and socio-environmental constraints such as the proximity to areas of ecological importance and indigenous communities to identify potential zones for solar and non-conventional renewable energy (NCRE)-based hydrogen production. To tackle this challenge we propose a methodology that utilizes geospatial analysis integrating Geographic Information System (GIS) tools with sensitivity analysis to determine the most suitable sites for PV plant installation in the Antofagasta region. Our geospatial analysis employs the QGIS software to identify these optimal locations while sensitivity analysis uses the Sørensen–Dice coefficient method to assess the similarity among chosen socio-environmental variables. Applying this methodology to the Antofagasta region reveals that a significant area within a 15 km radius of existing road networks and electrical substations is favorable for photovoltaic projects. Our sensitivity analysis further highlights the limiting effects of socio-environmental factors and their interactions. Moreover our research finds that enlarging areas of socio-environmental importance could increase the total hydrogen production by about 10% per commune indicating the impact of these factors on the potential for renewable energy production.
Alkaline Electrolysis for Hydrogen Production at Sea: Perspectives on Economic Performance
May 2023
Publication
Alkaline electrolysis is already a proven technology on land with a high maturity level and good economic performance. However at sea little is known about its economic performance toward hydrogen production. Alkaline electrolysis units operate with purified water to split its molecules into hydrogen and oxygen. Purified water and especially that sourced from the sea has a variable cost that ultimately depends on its quality. However the impurities present in that purified water have a deleterious effect on the electrolyte of alkaline electrolysis units that cause them to drop their energy efficiency. This in turn implies a source of economic losses resulting from the cost of electricity. In addition at sea there are various options regarding the electrolyte management of which the cost depends on various factors. All these factors ultimately impact on the levelized cost of the produced hydrogen. This article aims to shed some light on the economic performance of alkaline electrolysis units operating under sea conditions highlighting the knowledge gaps in the literature and initiating a debate in the field.
Hydrogen Environmental Benefits Depend on the Way of Production: An Overview of the Main Processes Production and Challenges by 2050
Jun 2021
Publication
Hydrogen (H2) is presented as an important alternative for clean energy and raw material in the modern world. However the environmental benefits are linked to its process of production. Herein the chemical aspects advantages/disadvantages and challenges of the main processes of H2 production from petroleum to water are described. The fossil fuel (FF)-based methods and the state-of-art strategies are outlined to produce hydrogen from water (electrolysis) wastewater and seawater. In addition a discussion based on a color code to classify the cleanliness of hydrogen production is introduced. By the end a summary of the hydrogen value chain addresses topics related to the financial aspects and perspective for 2050: green hydrogen and zero-emission carbon.
Selection Criteria and Ranking for Sustainable Hydrogen Production Options
Aug 2022
Publication
This paper aims to holistically study hydrogen production options essential for a sustainable and carbon-free future. This study also outlines the benefits and challenges of hydrogen production methods to provide sustainable alternatives to fossil fuels by meeting the global energy demand and net-zero targets. In this study sixteen hydrogen production methods are selected for sustainability investigation based on seven different criteria. The criteria selected in the comparative evaluation cover various dimensions of hydrogen production in terms of economic technical environmental and thermodynamic aspects for better sustainability. The current study results show that steam methane reforming with carbon capture could provide sustainable hydrogen in the near future while the other technologies’ maturity levels increase and the costs decrease. In the medium- and long-terms photonic and thermal-based hydrogen production methods can be the key to sustainable hydrogen production.
Understanding Degradation Effects of Elevated Temperature Operating Conditions in Polymer Electrolyte Water Electrolyzers
Apr 2021
Publication
The cost of polymer electrolyte water electrolysis (PEWE) is dominated by the price of electricity used to power the water splitting reaction. We present a liquid water fed polymer electrolyte water electrolyzer cell operated at a cell temperature of 100 °C in comparison to a cell operated at state-of-the-art operation temperature of 60 °C over a 300 h constant current period. The hydrogen conversion efficiency increases by up to 5% at elevated temperature and makes green hydrogen cheaper. However temperature is a stress factor that accelerates degradation causes in the cell. The PEWE cell operated at a cell temperature of 100 °C shows a 5 times increased cell voltage loss rate compared to the PEWE cell at 60 °C. The initial performance gain was found to be consumed after a projected operation time of 3500 h. Elevated temperature operation is only viable if a voltage loss rate of less than 5.8 μV h−1 can be attained. The major degradation phenomena that impact performance loss at 100 °C are ohmic (49%) and anode kinetic losses (45%). Damage to components was identified by post-test electron-microscopic analysis of the catalyst coated membrane and measurement of cation content in the drag water. The chemical decomposition of the ionomer increases by a factor of 10 at 100 °C vs 60 °C. Failure by short circuit formation was estimated to be a failure mode after a projected lifetime 3700 h. At elevated temperature and differential pressure operation hydrogen gas cross-over is limiting since a content of 4% hydrogen in oxygen represents the lower explosion limit.
A Comprehensive Review on the Power Supply System of Hydrogen Production Electrolyzers for Future Integrated Energy Systems
Feb 2024
Publication
Hydrogen energy is regarded as an ideal solution for addressing climate change issues and an indispensable part of future integrated energy systems. The most environmentally friendly hydrogen production method remains water electrolysis where the electrolyzer constructs the physical interface between electrical energy and hydrogen energy. However few articles have reviewed the electrolyzer from the perspective of power supply topology and control. This review is the first to discuss the positioning of the electrolyzer power supply in the future integrated energy system. The electrolyzer is reviewed from the perspective of the electrolysis method the market and the electrical interface modelling reflecting the requirement of the electrolyzer for power supply. Various electrolyzer power supply topologies are studied and reviewed. Although the most widely used topology in the current hydrogen production industry is still single-stage AC/DC the interleaved parallel LLC topology constructed by wideband gap power semiconductors and controlled by the zero-voltage switching algorithm has broad application prospects because of its advantages of high power density high efficiency fault tolerance and low current ripple. Taking into account the development trend of the EL power supply a hierarchical control framework is proposed as it can manage the operation performance of the power supply itself the electrolyzer the hydrogen energy domain and the entire integrated energy system.
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.
Model for Hydrogen Production Scheduling Optimisation
Feb 2024
Publication
This scientific article presents a developed model for optimising the scheduling of hydrogen production processes addressing the growing demand for efficient and sustainable energy sources. The study focuses on the integration of advanced scheduling techniques to improve the overall performance of the hydrogen electrolyser. The proposed model leverages constraint programming and satisfiability (CP-SAT) techniques to systematically analyse complex production schedules considering factors such as production unit capacities resource availability and energy costs. By incorporating real-world constraints such as fluctuating energy prices and the availability of renewable energy the optimisation model aims to improve overall operational efficiency and reduce production costs. The CP-SAT was applied to achieve more efficient control of the electrolysis process. The optimisation of the scheduling task was set for a 24 h time period with time resolutions of 1 h and 15 min. The performance of the proposed CP-SAT model in this study was then compared with the Monte Carlo Tree Search (MCTS)-based model (developed in our previous work). The CP-SAT was proven to perform better but has several limitations. The model response to the input parameter change has been analysed.
Towards a Multi-color Hydrogen Production Network? Competing Imaginaries of Development in Northern Patagonia, Argentina
Feb 2024
Publication
Green hydrogen has recently gained importance as a key element in the transition to a low-carbon energy future sparking a boom in possible production regions. This article aims at situating incipient hydrogen production in the Argentine province of Río Negro within a global production network (GPN). The early configuration of the hydrogen-GPN includes several stakeholders and is contested in many ways. To explore the possible materialization of the hydrogen economy in Argentina this article links GPN literature to the concept of sociotechnical imaginaries. In so doing this study finds three energy imaginaries linked to hydrogen development: First advocates of green hydrogen (GH2) project a sociotechnical imaginary in which GH2 is expected to promote scientific and technological progress. Second proponents of blue hydrogen point to Vaca Muerta and the role of natural gas for energy autonomy. Third opponents of the GH2 project question the underlying growth and export model emphasizing conservation and domestic energy sovereignty. The competition between different capital fractions i.e. green and fossil currently poses the risk of pro-fossil path decisions and lock-in effects. Current power constellations have led to the replacement of green with low-emission resulting in the promotion of multi-colored hydrogen. This is particularly evident in the draft for the new national hydrogen law and the actors involved in defining the national hydrogen strategy. The conceptual combination of actors and their interests their current power relations and the sociotechnical imaginaries they deploy illustrates how Argentina's energy future is already being shaped today.
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