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Enhancing Waste-to-Energy and Hydrogen Production through Urban–Industrial Symbiosis: A Multi-Objective Optimisation Model Incorporating a Bayesian Best-Worst Method
Mar 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.
Electrochemical Devices to Power a Sustainable Energy Transition—An Overview of Green Hydrogen Contribution
Mar 2024
Publication
This work discusses the current scenario and future growth of electrochemical energy devices such as water electrolyzers and fuel cells. It is based on the pivotal role that hydrogen can play as an energy carrier to replace fossil fuels. Moreover it is envisaged that the scaled-up and broader deployment of the technologies can hold the potential to address the challenges associated with intermittent renewable energy generation. From a sustainability perspective this synergy between hydrogen and electricity from renewable sources is particularly attractive: electrolyzers convert the excess energy from renewables into green hydrogen and fuel cells use this hydrogen to convert it back into electricity when it is needed. Although this transition endorses the ambitious goal to supply greener energy for all it also entails increased demand for the materials that are essential for developing such cleaner energy technologies. Herein several economic and environmental issues are highlighted besides a critical overview regarding each technology. The aim is to raise awareness and provide the reader (a non-specialist in the field) with useful resources regarding the challenges that need to be overcome so that a green hydrogen energy transition and a better life can be fully achieved.
The Influence of the Changes in Natural Gas Supplies to Poland on the Amount of Hydrogen Produced in the SMR Reactor
Mar 2024
Publication
Thanks to investments in diversifying the supply of natural gas Poland did not encounter any gas supply issues in 2022 when gas imports from Russia were ceased due to the Russian Federation’s armed intervention in Ukraine. Over the past few years the supply of gas from routes other than the eastern route has substantially grown particularly the supplies of liquefied natural gas (LNG) via the LNG terminal in Swinouj´scie. The growing proportion of LNG in Poland’s gas supply ´ leads to a rise in ethane levels in natural gas as verified by the review of data taken at a specific location within the gas system over the years 2015 2020 and 2022. Using measurements of natural gas composition the effectiveness of the steam hydrocarbon reforming process was simulated in the Gibbs reactor via Aspen HYSYS. The simulations confirmed that as the concentration of ethane in the natural gas increased the amount of hydrogen produced and the heat required for reactions in the reformer also increased. This article aims to analyze the influence of the changes in natural gas quality in the Polish transmission network caused by changes in supply structures on the mass and heat balance of the theoretical steam reforming reactor. Nowadays the chemical composition of natural gas may be significantly different from that assumed years ago at the plant’s design stage. The consequence of such a situation may be difficulties in operating especially when controlling the quantity of incoming natural gas to the reactor based on volumetric flow without considering changes in chemical composition.
Drifting toward Alliance Innovation: Patent Collaboration Relationships and Development in China’s Hydrogen Energy Industry from a Network Perspective
Mar 2024
Publication
The hydrogen energy industry as one of the most important directions for future energy transformation can promote the sustainable development of the global economy and of society. China has raised the development of hydrogen energy to a strategic position. Based on the patent data in the past two decades this study investigates the collaborative innovation relationships in China’s hydrogen energy field using complex network theory. Firstly patent data filed between 2003 and 2023 are analyzed and compared in terms of time geography and institutional and technological dimensions. Subsequently a patent collaborative innovation network is constructed to explore the fundamental characteristics and evolutionary patterns over five stages. Furthermore centrality measures and community detection algorithms are utilized to identify core entities and innovation alliances within the network which reveal that China’s hydrogen energy industry is drifting toward alliance innovation. The study results show the following: (1) the network has grown rapidly in size and scope over the last two decades and evolved from the initial stage to the multi-center stage before forming innovation alliances; (2) core innovative entities are important supports and bridges for China’s hydrogen energy industry and control most resources and maintain the robustness of the whole network; (3) innovation alliances reveal the closeness of the collaborative relationships between innovative entities and the potential landscape of China’s hydrogen energy industry; and (4) most of the innovation alliances cooperate only on a narrow range of technologies which may hinder the overall sustainable growth of the hydrogen energy industry. Thereafter some suggestions are put forward from the perspective of an industrial chain and innovation chain which may provide a theoretical reference for collaborative innovation and the future development and planning in the field of hydrogen energy in China.
Integration of Different Storage Technologies towards Sustainable Development—A Case Study in a Greek Island
Mar 2024
Publication
The necessity for transitioning to renewable energy sources and the intermittent nature of the natural variables lead to the integration of storage units into these projects. In this research paper wind turbines and solar modules are combined with pumped hydro storage batteries and green hydrogen. Energy management strategies are described for five different scenarios of hybrid renewable energy systems based on single or hybrid storage technologies. The motivation is driven by grid stability issues and the limited access to fresh water in the Greek islands. A RES-based desalination unit is introduced into the hybrid system for access to low-cost fresh water. The comparison of single and hybrid storage methods the exploitation of seawater for the simultaneous fulfillment of water for domestic and agricultural purposes and the evaluation of different energy economic and environmental indices are the innovative aspects of this research work. The results show that pumped hydro storage systems can cover the energy and water demand at the minimum possible price 0.215 EUR/kWh and 1.257 EUR/m3 while hybrid storage technologies provide better results in the loss of load probability payback period and CO2 emissions. For the pumped hydro– hydrogen hybrid storage system these values are 21.40% 10.87 years and 2297 tn/year respectively.
Internal Combustion Engines and Carbon-Neutral Fuels: A Perspective on Emission Neutrality in the European Union
Mar 2024
Publication
Nowadays there is an intense debate in the European Union (EU) regarding the limits to achieve the European Green Deal to make Europe the first climate-neutral continent in the world. In this context there are also different opinions about the role that thermal engines should play. Furhermore there is no clear proposal regarding the possibilities of the use of green hydrogen in the transport decarbonization process even though it should be a key element. Thus there are still no precise guidelines regarding the role of green hydrogen with it being exclusively used as a raw material to produce E-fuels. This review aims to evaluate the possibilities of applying the different alternative technologies available to successfully complete the process already underway to achieve Climate Neutrality by about 2050 depending on the maturity of the technologies currently available and those anticipated to be available in the coming decades.
Carbon Footprint Enhancement of an Agricultural Telehandler through the Application of a Fuel Cell Powertrain
Mar 2024
Publication
The growing awareness about climate change and environmental pollution is pushing the industrial and academic world to investigate more sustainable solutions to reduce the impact of anthropic activities. As a consequence a process of electrification is involving all kind of vehicles with a view to gradually substitute traditional powertrains that emit several pollutants in the exhaust due to the combustion process. In this context fuel cell powertrains are a more promising strategy with respect to battery electric alternatives where productivity and endurance are crucial. It is important to replace internal combustion engines in those vehicles such as the those in the sector of NonRoad Mobile Machinery. In the present paper a preliminary analysis of a fuel cell powertrain for a telehandler is proposed. The analysis focused on performance fuel economy durability applicability and environmental impact of the vehicle. Numerical models were built in MATLAB/Simulink and a simple power follower strategy was developed with the aim of reducing components degradation and to guarantee a charge sustaining operation. Simulations were carried out regarding both peak power conditions and a typical real work scenario. The simulations’ results showed that the fuel cell powertrain was able to achieve almost the same performances without excessive stress on its components. Indeed a degradation analysis was conducted showing that the fuel cell system can achieve satisfactory durability. Moreover a Well-to-Wheel approach was adopted to evaluate the benefits in terms of greenhouse gases of adopting the fuel cell system. The results of the analysis demonstrated that even if considering grey hydrogen to feed the fuel cell system the proposed powertrain can reduce the equivalent CO2 emissions of 69%. This reduction can be further enhanced using hydrogen from cleaner production processes. The proposed preliminary analysis demonstrated that fuel cell powertrains can be a feasible solution to substitute traditional systems on off-road vehicles even if a higher investment cost might be required.
Thermal Sprayed Protective Coatings for Bipolar Plates of Hydrogen Fuel Cells and Water Electrolysis Cells
Mar 2024
Publication
As one core component in hydrogen fuel cells and water electrolysis cells bipolar plates (BPs) perform multiple important functions such as separating the fuel and oxidant flow providing mechanical support conducting electricity and heat connecting the cell units into a stack etc. On the path toward commercialization the manufacturing costs of bipolar plates have to be substantially reduced by adopting low-cost and easy-to-process metallic materials (e.g. stainless steel aluminum or copper). However these materials are susceptible to electrochemical corrosion under harsh operating conditions resulting in long-term performance degradation. By means of advanced thermal spraying technologies protective coatings can be prepared on bipolar plates so as to inhibit oxidation and corrosion. This paper reviews several typical thermal spraying technologies including atmospheric plasma spraying (APS) vacuum plasma spraying (VPS) and high-velocity oxygen fuel (HVOF) spraying for preparing coatings of bipolar plates particularly emphasizing the effect of spraying processes on coating effectiveness. The performance of coatings relies not only on the materials as selected or designed but also on the composition and microstructure practically obtained in the spraying process. The temperature and velocity of in-flight particles have a significant impact on coating quality; therefore precise control over these factors is demanded.
Research on Fast Frequency Response Control Strategy of Hydrogen Production Systems
Mar 2024
Publication
With the large-scale integration of intermittent renewable energy generation presented by wind and photovoltaic power the security and stability of power system operations have been challenged. Therefore this article proposes a control strategy of a hydrogen production system based on renewable energy power generation to enable the fast frequency response of a grid. Firstly based on the idea of virtual synchronous control a fast frequency response control transformation strategy for the grid-connected interface of hydrogen production systems for renewable energy power generation is proposed to provide active power support when the grid frequency is disturbed. Secondly based on the influence of VSG’s inertia and damping coefficient on the dynamic characteristics of the system a VSG adaptive control model based on particle swarm optimization is designed. Finally based on the Matlab/Simulink platform a grid-connected simulation model of hydrogen production systems for renewable energy power generation is established. The results show that the interface-transformed electrolytic hydrogen production device can actively respond to the frequency disturbances of the power system and participate in primary frequency control providing active support for the frequency stability of the power system under high-percentage renewable energy generation integration. Moreover the system with parameter optimization has better fast frequency response control characteristics.
Experimental Study of a Homogeneous Charge Compression Ignition Engine Using Hydrogen at High-Altitude Conditions
Feb 2024
Publication
One of the key factors of the current energy transition is the use of hydrogen (H2 ) as fuel in energy transformation technologies. This fuel has the advantage of being produced from the most primary forms of energy and has the potential to reduce carbon dioxide (CO2 ) emissions. In recent years hydrogen or hydrogen-rich mixtures in internal combustion engines (ICEs) have gained popularity with numerous reports documenting their use in spark ignition (SI) and compression ignition (CI) engines. Homogeneous charge compression ignition (HCCI) engines have the potential for substantial reductions in nitrogen oxides (NOx) and particulate matter (PM) emissions and the use of hydrogen along with this kind of combustion could substantially reduce CO2 emissions. However there have been few reports using hydrogen in HCCI engines with most studies limited to evaluating technical feasibility combustion characteristics engine performance and emissions in laboratory settings at sea level. This paper presents a study of HCCI combustion using hydrogen in a stationary air-cooled Lombardini 25 LD 425-2 modified diesel engine located at 1495 m above sea level. An experimental phase was conducted to determine the intake temperature requirements and equivalence ratios for stable HCCI combustion. These results were compared with previous research carried out at sea level. To the best knowledge of the authors this is the first report on the combustion and operational limits for an HCCI engine fueled with hydrogen under the mentioned specific conditions. Equivalence ratios between 0.21 and 0.28 and intake temperatures between 188 ◦C and 235 ◦C effectively achieved the HCCI combustion. These temperature values were on average 100 ◦C higher than those reported in previous studies. The maximum value for the indicated mean effective pressure (IMEPn) was 1.75 bar and the maximum thermal efficiency (ITEn) was 34.5%. The achieved results are important for the design and implementation of HCCI engines running solely on hydrogen in developing countries located at high altitudes above sea level.
Explaining Varying Speeds of Low-carbon Reorientation in the United Kingdom's Steel, Petrochemical, and Oil Refining Industries: A Multi-dimensional Comparative Analysis and Outlook
Feb 2024
Publication
Accelerated decarbonisation of steelmaking oil refining and petrochemical industries is essential for climate change mitigation. Drawing on three longitudinal case studies of these industries in the UK this synthesis article makes a comparative analysis of their varying low-carbon reorientation speeds. The paper uses the triple embeddedness framework to analyse five factors (policy support international competition financial health technical feasibility corporate strategy and mindset) that explain why UK oil refineries have in recent years been comparatively the fastest in their low-carbon reorientation and UK steelmakers the slowest. We find that policy support has been more beneficial for refining and petrochemicals than for steel although recent government deals with steelmakers addressed this imbalance. International competition has been high for steel and petrochemicals and comparatively lower for refining (meaning that decarbonisation costs are less detrimental for international competitiveness). Financial performance has comparatively been worst for steel and best for oil refining which shapes the economic feasibility of low-carbon options. Hydrogen and carbon-capture-and-storage are technologically feasible for refining and petrochemicals while Electric Arc Furnaces are technically feasible for steelmakers but face wider feasibility problems (with scrap steel supply electricity grids and electricity prices) which is why we question the recent government deals. Corporate strategy and perceptions changed in oil refining with firms seeing economic opportunities in decarbonisation while steelmakers and petrochemical firms still mostly see decarbonisation as a burden and threat. The paper ends with comparative conclusions a discussion of political considerations and future outlooks for the three UK industries policy and research.
Benchmark of J55 and X56 Steels on Cracking and Corrosion Effects Under Hydrogen Salt Cavern Boundary Conditions
Feb 2024
Publication
Salt caverns have great potential to store relevant amounts of hydrogen as part of the energy transition. However the durability and suitability of commonly used steels for piping in hydrogen salt caverns is still under research. In this work aging effects focusing on corrosion and cracking patterns of casing steel API 5CT J55 and “H2ready” pipeline steel API 5L X56 were investigated with scanning electron microscopy and energy dispersive X-ray spectroscopy after accelerated stress tests with pressure/temperature cycling under hydrogen salt cavern-like conditions. Compared to dry conditions significant more corrosion by presence of salt ions was detected. However compared to X56 only for J55 an intensification of corrosion and cracking at the surface due to hydrogen atmosphere was revealed. Pronounced surface cracks were observed for J55 over the entire samples. Overall the results strongly suggest that X56 is more resistant than J55 under the conditions of a hydrogen salt cavern.
Hydrogen Fuel Cell as an Electric Generator: A Case Study for a General Cargo Ship
Feb 2024
Publication
In this study real voyage data and ship specifications of a general cargo ship are employed and it is assumed that diesel generators are replaced with hydrogen proton exchange membrane fuel cells. The effect of the replacement on CO2 NOX SOX and PM emissions and the CII value is calculated. Emission calculations show that there is a significant reduction in emissions when hydrogen fuel cells are used instead of diesel generators on the case ship. By using hydrogen fuel cells there is a 37.4% reduction in CO2 emissions 32.5% in NOX emissions 37.3% in SOX emissions and 37.4% in PM emissions. If hydrogen fuel cells are not used instead of diesel generators the ship will receive an A rating between 2023 and 2026 a B rating in 2027 a C rating in 2028–2029 and an E rating in 2030. On the other hand if hydrogen fuel cells are used the ship will always remain at an A rating between 2023 and 2030. The capital expenditure (CAPEX) and operational expenditure (OPEX) of the fuel cell system are USD 1305720 and USD 2470320 respectively for a 15-year lifetime and the hydrogen fuel expenses are competitive at USD 260981 while marine diesel oil (MDO) fuel expenses are USD 206435.
Upcycling of Plastic Wastes for Hydrogen Production: Advances and Perspectives
Feb 2024
Publication
The abundant plastic wastes become an imperative global issue and how to handle these organic wastes gains growing scientific and industrial interest. Recently converting plastic wastes into hydrogen fuel has been investigated and the “waste-to-value” practice accelerates the circular economy. To accelerate the development of plastic-to-hydrogen conversion in this review recent advances in plastic-to-hydrogen conversion via thermochemical photocatalytic and electrocatalytic routes are analyzed. All of the thermo- photo- and electrochemical processes can transform different plastic wastes into hydrogen and the hydrogen production efficiency depends heavily on the selected techniques operating parameters and applied catalysts. The application of rational-designed catalysts can promote the selective production of hydrogen from plastic feedstocks. Further studies on process optimization cost-effective catalyst design and mechanism investigation are needed.
Levelized Cost of Biohydrogen from Steam Reforming of Biomethane with Carbon Capture and Storage (Golden Hydrogen)—Application to Spain
Feb 2024
Publication
The production of biohydrogen with negative CO2 emissions through the steam methane reforming of biomethane coupled with carbon capture and storage represents a promising technology particularly for industries that are difficult to electrify. In spite of the maturity of this technology which is currently employed in the production of grey and blue hydrogen a detailed cost model that considers the entire supply chain is lacking in the literature. This study addresses this gap by applying correlations derived from actual facilities producing grey and blue hydrogen to calculate the CAPEX while exploring various feedstock combinations for biogas generation to assess the OPEX. The analysis also includes logistic aspects such as decentralised biogas production and the transportation and storage of CO2 . The levelized cost of golden hydrogen is estimated to range from EUR 1.84 to 2.88/kg compared to EUR 1.47/kg for grey hydrogen and EUR 1.93/kg for blue hydrogen assuming a natural gas cost of EUR 25/MWh and excluding the CO2 tax. This range increases to between 3.84 and 2.92 with a natural gas cost of EUR 40/MWh with the inclusion of the CO2 tax. A comparison with conventional green hydrogen is performed highlighting both prices and potential thereby offering valuable information for decision-making.
Experimental Investigations of the Hydrogen Injectors on the Combustion Characteristics and Performance of a Hydrogen Internal Combustion Engine
Feb 2024
Publication
Hydrogen is regarded as an ideal zero-carbon fuel for an internal combustion engine. However the low mass flow rate of the hydrogen injector and the low volume heat value of the hydrogen strongly restrict the enhancement of the hydrogen engine performance. This experimental study compared the effects of single-injectors and double-injectors on the engine performance combustion pressure heat release rate and the coefficient of variation (CoVIMEP) based on a singlecylinder 0.5 L port fuel injection hydrogen engine. The results indicated that the number of hydrogen injectors significantly influences the engine performance. The maximum brake power is improved from 4.3 kW to 6.12 kW when adding the injector. The test demonstrates that the utilization of the double-injector leads to a reduction in hydrogen obstruction in the intake manifold consequently minimizing the pumping losses. The pump mean effective pressure decreased from −0.049 MPa in the single-injector condition to −0.029 MPa in the double-injector condition with the medium loads. Furthermore the double-injector exhibits excellent performance in reducing the coefficient of variation. The maximum CoVIMEP decreased from 2.18% in the single-injector configuration to 1.92% in the double-injector configuration. This result provides new insights for optimizing hydrogen engine injector design and optimizing the combustion process.
Effects of Hydrogen, Methane, and Their Blends on Rapid-Filling Process of High-Pressure Composite Tank
Feb 2024
Publication
Alternative fuels such as hydrogen compressed natural gas and liquefied natural gas are considered as feasible energy carriers. Selected positive factors from the EU climate and energy policy on achieving climate neutrality by 2050 highlighted the need for the gradual expansion of the infrastructure for alternative fuel. In this research continuity equations and the first and second laws of thermodynamics were used to develop a theoretical model to explore the impact of hydrogen and natural gas on both the filling process and the ultimate in-cylinder conditions of a type IV composite cylinder (20 MPa for CNG 35 MPa and 70 MPa for hydrogen). A composite tank was considered an adiabatic system. Within this study based on the GERG-2008 equation of state a thermodynamic model was developed to compare and determine the influence of (i) hydrogen and (ii) natural gas on the selected thermodynamic parameters during the fast-filling process. The obtained results show that the cylinder-filling time depending on the cylinder capacity is approximately 36–37% shorter for pure hydrogen compared to pure methane and the maximum energy stored in the storage tank for pure hydrogen is approximately 28% lower compared to methane whereas the total entropy generation for pure hydrogen is approximately 52% higher compared to pure methane.
Multi-Objective Robust Optimization of Integrated Energy System with Hydrogen Energy Storage
Feb 2024
Publication
A novel multi-objective robust optimization model of an integrated energy system with hydrogen storage (HIES) considering source–load uncertainty is proposed to promote the low-carbon economy operation of the integrated energy system of a park. Firstly the lowest total system cost and carbon emissions are selected as the multi-objective optimization functions. The Pareto front solution set of the objective function is applied by compromise planning and the optimal solution among them is obtained by the maximum–minimum fuzzy method. Furthermore the robust optimization (RO) approach is introduced to cope with the source–load uncertainty effectively. Finally it is demonstrated that the illustrated HIES can significantly reduce the total system cost carbon emissions and abandoned wind and solar power. Meanwhile the effectiveness of the proposed model and solution method is verified by analyzing the influence of multi-objective solutions and a robust coefficient on the Chongli Demonstration Project in Hebei Province.
A Review of Gas Phase Inhibition of Gaseous Hydrogen Embrittlement in Pipeline Steels
Feb 2024
Publication
The addition of small amounts of certain gases such as O2 CO and SO2 may mitigate hydrogen embrittlement in high-pressure gas transmission pipelines that transport hydrogen. To practically implement such inhibition in gas transmission pipelines a comprehensive understanding and quantification of this effect are essential. This review examines the impact of various added gases to hydrogen including typical odorants on gaseous hydrogen embrittlement of steels and evaluates their inhibition effectiveness. O2 CO and SO2 were found to be effective inhibitors of hydrogen embrittlement. Yet the results in the literature have not always been consistent partly because of the diverse range of mechanical tests and their parameters. The absence of systematic studies hinders the evaluation of the feasibility of using gas phase inhibitors for controlling gaseous hydrogen embrittlement. A method to quantify the effectiveness of gas phase inhibition is proposed using gas phase permeation studies.
Hopes and Fears for a Sustainable Energy Future: Enter the Hydrogen Acceptance Matrix
Feb 2024
Publication
Hydrogen-fuelled technologies for home heating and cooking may provide a low-carbon solution for decarbonising parts of the global housing stock. For the transition to transpire the attitudes and perceptions of consumers must be factored into policy making efforts. However empirical studies are yet to explore potential levels of consumer heterogeneity regarding domestic hydrogen acceptance. In response this study explores a wide spectrum of consumer responses towards the prospect of hydrogen homes. The proposed spectrum is conceptualised in terms of the ‘domestic hydrogen acceptance matrix’ which is examined through a nationally representative online survey conducted in the United Kingdom. The results draw attention to the importance of interest and engagement in environmental issues knowledge and awareness of renewable energy technologies and early adoption potential as key drivers of domestic hydrogen acceptance. Critically strategic measures should be taken to convert hydrogen scepticism and pessimism into hope and optimism by recognising the multidimensional nature of consumer acceptance. To this end resources should be dedicated towards increasing the observability and trialability of hydrogen homes in proximity to industrial clusters and hubs where the stakes for consumer acceptance are highest. Progress towards realising a net-zero society can be supported by early stakeholder engagement with the domestic hydrogen acceptance matrix.
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