- Home
- A-Z Publications
- Publications
Publications
Potential Role of Natural Gas Infrastructure in China to Supply Low-carbon Gases During 2020–2050
Oct 2021
Publication
As natural gas (NG) demand increases in China the question arises how the NG infrastructure fit into a low greenhouse gas (GHG) emissions future towards 2050. Herein the potential role of the NG infrastructure in supplying low-carbon gases during 2020–2050 for China at a provincial resolution was analyzed for different scenarios. In total four low-carbon gases were considered in this study: biomethane bio-synthetic methane hydrogen and low-carbon synthetic methane. The results show that the total potential of low-carbon gas production can increase from 1.21 EJ to 5.25 EJ during 2020–2050 which can replace 20%–67% of the imported gas. In particular Yunnan and Inner Mongolia contribute 17% of China’s low-carbon gas production. As the deployment of NG infrastructure can be very different three scenarios replacing imported pipeline NG were found to reduce the expansion of gas infrastructure by 35%–42% while the three scenarios replacing LNG imports were found to increase infrastructure expansion by 31%–53% as compared to the base case. The cumulative avoided GHG emissions for the 6 analyzed scenarios were 6.0–8.3 Gt CO2. The GHG avoidance costs were highly influenced by the NG price. This study shows that the NG infrastructure has the potential to supply low-carbon gases in China thereby significantly reducing GHG emissions and increasing both China’s short- and long-term gas supply independence.
Comparative Analysis of Energy and Exergy Performance of Hydrogen Production Methods
Nov 2020
Publication
The study of the viability of hydrogen production as a sustainable energy source is a current challenge to satisfy the great world energy demand. There are several techniques to produce hydrogen either mature or under development. The election of the hydrogen production method will have a high impact on practical sustainability of the hydrogen economy. An important profile for the viability of a process is the calculation of energy and exergy efficiencies as well as their overall integration into the circular economy. To carry out theoretical energy and exergy analyses we have estimated proposed hydrogen production using different software (DWSIM and MATLAB) and reference conditions. The analysis consolidates methane reforming or auto-thermal reforming as the viable technologies at the present state of the art with reasonable energy and exergy efficiencies but pending on the impact of environmental constraints as CO2 emission countermeasures. However natural gas or electrolysis show very promising results and should be advanced in their technological and maturity scaling. Electrolysis shows a very good exergy efficiency due to the fact that electricity itself is a high exergy source. Pyrolysis exergy loses are mostly in the form of solid carbon material which has a very high integration potential into the hydrogen economy.
The Future of Clean Hydrogen in the United States: Views from Industry, Market Innovators, and Investors
Sep 2021
Publication
This report The Future of Clean Hydrogen in the United States: Views from Industry Market Innovators and Investors sheds light on the rapidly evolving hydrogen market based on 72 exploratory interviews with organizations across the current and emerging hydrogen value chain. This report is part of a series From Kilograms to Gigatons: Pathways for Hydrogen Market Formation in the United States which will build on this study to evaluate policy opportunities for further hydrogen development in the United States. The goal of the interviews was to provide a snapshot of the clean hydrogen investment environment and better understand organizations’ market outlook investment rationale and areas of interest. This interview approach was supported by traditional research methods to contextualize and enrich the qualitative findings. This report should be understood as input to a more extensive EFI analysis of hydrogen market formation in the United States; the directions that companies are pursuing in hydrogen production transport and storage and end use at this early stage of value chain development will inform subsequent analysis in important ways.
Scientific Assessment in Support of the Materials Roadmap enabling Low Carbon Energy Technologies Hydrogen and Fuel Cells
Apr 2014
Publication
A group experts from European research organisations and industry have assessed the state of the art and future needs for materials' R&D for hydrogen and fuel cell technologies. The work was performed as input to the European Commission's roadmapping exercise on materials for the European Strategic Energy Technology Plan. The report summarises the results including key targets identified for medium term (2020/2030) and long term (2050) timescales.
Evaluation of Stability and Catalytic Activity of Ni Catalysts for Hydrogen Production by Biomass Gasification in Supercritical Water
Mar 2019
Publication
Supercritical water gasification is a promising technology for wet biomass utilization. In this paper Ni and other metal catalysts were synthesized by wet impregnation. The stability and catalytic activities of Ni catalysts were evaluated. Firstly catalytic activities of Ni Fe Cu catalysts supported on MgO were tested using wheat straw as raw material in a batch reactor at 723 K and water density of 0.07 cm3/g. Experimental results showed that the order of metal catalyst activity for hydrogen generation was Ni/MgO > Fe/MgO > Cu/MgO. Secondly the influence of different supports on Ni catalysts performance was investigated. The results showed that the order of the Ni catalysts’ activity with different supports was Ni/MgO > Ni/ZnO > Ni/Al2O3 > Ni/ZrO2. Finally the effects of Ni loading and the amount of Ni catalyst addition on hydrogen production and the stability of Ni/MgO catalyst were studied. It was found that serious deactivation of Ni catalyst in the process of supercritical water gasification took place. Even if carbon deposited on the catalyst surface was removed by high temperature calcination and the catalyst was reduced with hydrogen the activity of used catalyst was only partially restored.
Thermal Management System Architecture for Hydrogen-Powered Propulsion Technologies: Practices, Thematic Clusters, System Architectures, Future Challenges, and Opportunities
Jan 2022
Publication
The thermal management system architectures proposed for hydrogen-powered propulsion technologies are critically reviewed and assessed. The objectives of this paper are to determine the system-level shortcomings and to recognise the remaining challenges and research questions that need to be sorted out in order to enable this disruptive technology to be utilised by propulsion system manufacturers. Initially a scientometrics based co-word analysis is conducted to identify the milestones for the literature review as well as to illustrate the connections between relevant ideas by considering the patterns of co-occurrence of words. Then a historical review of the proposed embodiments and concepts dating back to 1995 is followed. Next feasible thermal management system architectures are classified into three distinct classes and its components are discussed. These architectures are further extended and adapted for the application of hydrogen-powered fuel cells in aviation. This climaxes with the assessment of the available evidence to verify the reasons why no hydrogen-powered propulsion thermal management system architecture has yet been approved for commercial production. Finally the remaining research challenges are identified through a systematic examination of the critical areas in thermal management systems for application to hydrogen-powered air vehicles’ engine cooling. The proposed solutions are discussed from weight cost complexity and impact points of view by a system-level assessment of the critical areas in the field.
A Novel Remaining Useful Life Prediction Method for Hydrogen Fuel Cells Based on the Gated Recurrent Unit Neural Network
Jan 2022
Publication
The remaining useful life (RUL) prediction for hydrogen fuel cells is an important part of its prognostics and health management (PHM). Artificial neural networks (ANNs) are proven to be very effective in RUL prediction as they do not need to understand the failure mechanisms behind hydrogen fuel cells. A novel RUL prediction method for hydrogen fuel cells based on the gated recurrent unit ANN is proposed in this paper. Firstly the data were preprocessed to remove outliers and noises. Secondly the performance of different neural networks is compared including the back propagation neural network (BPNN) the long short-term memory (LSTM) network and the gated recurrent unit (GRU) network. According to our proposed method based on GRU the root mean square error was 0.0026 the mean absolute percentage error was 0.0038 and the coefficient of determination was 0.9891 for the data from the challenge datasets provided by FCLAB Research Federation when the prediction starting point was 650 h. Compared with the other RUL prediction methods based on the BPNN and the LSTM our prediction method is better in both prediction accuracy and convergence rate.
New Combustion Modelling Approach for Methane-Hydrogen Fueled Engines Using Machine Learning and Engine Virtualization
Oct 2021
Publication
The achievement of a carbon-free emissions economy is one of the main goals to reduce climate change and its negative effects. Scientists and technological improvements have followed this trend improving efficiency and reducing carbon and other compounds that foment climate change. Since the main contributor of these emissions is transportation detaching this sector from fossil fuels is a necessary step towards an environmentally friendly future. Therefore an evaluation of alternative fuels will be needed to find a suitable replacement for traditional fossil-based fuels. In this scenario hydrogen appears as a possible solution. However the existence of the drawbacks associated with the application of H2 -ICE redirects the solution to dual-fuel strategies which consist of mixing different fuels to reduce negative aspects of their separate use while enhancing the benefits. In this work a new combustion modelling approach based on machine learning (ML) modeling is proposed for predicting the burning rate of different mixtures of methane (CH4 ) and hydrogen (H2). Laminar flame speed calculations have been performed to train the ML model finding a faster way to obtain good results in comparison with actual models applied to SI engines in the virtual engine model framework.
Building Efficiency- Reducing Energy Demand in the Commercial Sector
Dec 2013
Publication
The report was formally launched on 2nd December in Parliament at a panel debate chaired by Lord Whitty and Oliver Colvile and featured representatives from Government and Industry. The report outlines the case for investment by businesses in the energy efficiency of their buildings and operations and highlights how this could help neutralise the threat to profitability posed by increasing energy bills energy price volatility and an increasing reliance on electricity in the commercial sector. The report highlights that business in the UK have the opportunity to not only reduce energy bills but increase their competitiveness and improve worker productivity through better designed buildings.
Optimising Air Quality Co-benefits in a Hydrogen Economy: A Case for Hydrogen-specific Standards for NOx Emissions
Jun 2021
Publication
A global transition to hydrogen fuel offers major opportunities to decarbonise a range of different energyintensive sectors from large-scale electricity generation through to heating in homes. Hydrogen can be deployed as an energy source in two distinct ways in electrochemical fuel cells and via combustion. Combustion seems likely to be a major pathway given that it requires only incremental technological change. The use of hydrogen is not however without side-effects and the widely claimed benefit that only water is released as a by-product is only accurate when it is used in fuel cells. The burning of hydrogen can lead to the thermal formation of nitrogen oxides (NOx – the sum of NO + NO2) via a mechanism that also applies to the combustion of fossil fuels. NO2 is a key air pollutant that is harmful in its own right and is a precursor to other pollutants of concern such as fine particulate matter and ozone. Minimising NOx as a by-product from hydrogen boilers and engines is possible through control of combustion conditions but this can lead to reduced power output and performance. After-treatment and removal of NOx is possible but this increases cost and complexity in appliances. Combustion applications therefore require optimisation and potentially lower hydrogen-specific emissions standards if the greatest air quality benefits are to derive from a growth in hydrogen use
Porosity and Thickness Effect of Pd–Cu–Si Metallic Glasses on Electrocatalytic Hydrogen Production and Storage
Aug 2021
Publication
This contribution places emphasis on tuning pore architecture and film thickness of mesoporous Pd–Cu–Si thin films sputtered on Si/SiO2 substrates for enhanced electrocatalytic and hydrogen sorption/desorption activity and their comparison with the state-of-the-art thin film electrocatalysts. Small Tafel slope of 43 mV dec–1 for 1250 nm thick coatings with 2 µm diameter pores with 4.2 µm interspacing (H2) electrocatalyst with comparable hydrogen overpotentials to the literature suggests its use for standard fuel cells. The largest hydrogen sorption has been attained for the 250 nm thick electrocatalyst on 5 µm pore diameter and 12 µm interspacing (2189 µC cm–2 per CV cycle) making it possible for rapid storage systems. Moreover the charge transfer resistance described by an equivalent circuit model has an excellent correlation with Tafel slopes. Along with its very low Tafel slope of 42 mV dec–1 10 nm thick H2 pore design electrocatalyst has the highest capacitive response of ∼0.001 S sn cm–2 and is promising to be used as a nano-charger and hydrogen sensor.
Fundamentals, Materials, and Machine Learning of Polymer Electrolyte Membrane Fuel Cell Technology
Jun 2020
Publication
Polymer electrolyte membrane (PEM) fuel cells are electrochemical devices that directly convert the chemical energy stored in fuel into electrical energy with a practical conversion efficiency as high as 65%. In the past years significant progress has been made in PEM fuel cell commercialization. By 2019 there were over 19000 fuel cell electric vehicles (FCEV) and 340 hydrogen refueling stations (HRF) in the U.S. (~8000 and 44 respectively) Japan (~3600 and 112 respectively) South Korea (~5000 and 34 respectively) Europe (~2500 and 140 respectively) and China (~110 and 12 respectively). Japan South Korea and China plan to build approximately 3000 HRF stations by 2030. In 2019 Hyundai Nexo and Toyota Mirai accounted for approximately 63% and 32% of the total sales with a driving range of 380 and 312 miles and a mile per gallon (MPGe) of 65 and 67 respectively. Fundamentals of PEM fuel cells play a crucial role in the technological advancement to improve fuel cell performance/durability and reduce cost. Several key aspects for fuel cell design operational control and material development such as durability electrocatalyst materials water and thermal management dynamic operation and cold start are briefly explained in this work. Machine learning and artificial intelligence (AI) have received increasing attention in material/energy development. This review also discusses their applications and potential in the development of fundamental knowledge and correlations material selection and improvement cell design and optimization system control power management and monitoring of operation health for PEM fuel cells along with main physics in PEM fuel cells for physics-informed machine learning. The objective of this review is three fold: (1) to present the most recent status of PEM fuel cell applications in the portable stationary and transportation sectors; (2) to describe the important fundamentals for the further advancement of fuel cell technology in terms of design and control optimization cost reduction and durability improvement; and (3) to explain machine learning physics-informed deep learning and AI methods and describe their significant potentials in PEM fuel cell research and development (R&D).
Evaluation of Zero-Energy Building and Use of Renewable Energy in Renovated Buildings: A Case Study in Japan
Apr 2022
Publication
Following the Paris Agreement in 2015 the worldwide focus on global warming countermeasures has intensified. The Japanese government has declared its aim at achieving carbon neutrality by 2050. The concept of zero-energy buildings (ZEBs) is based on measures to reduce energy consumption in buildings the prospects of which are gradually increasing. This study investigated the annual primary energy consumption; as well as evaluated renewed and renovated buildings that had a solar power generation system and utilized solar and geothermal heat. It further examines the prospects of hydrogen production from on-site surplus electricity and the use of hydrogen fuel cells. A considerable difference was observed between the actual energy consumption (213 MJ/m2 ) and the energy consumption estimated using an energy simulation program (386 MJ/m2 ). Considerable savings of energy were achieved when evaluated based on the actual annual primary energy consumption of a building. The building attained a near net zero-energy consumption considering the power generated from the photovoltaic system. The study showed potential energy savings in the building by producing hydrogen using surplus electricity from on-site power generation and introducing hydrogen fuel cells. It is projected that a building’s energy consumption will be lowered by employing the electricity generated by the hydrogen fuel cell for standby power water heating and regenerating heat from the desiccant system.
Thermodynamic Analysis of Solid Oxide Electrolyzer Integration with Engine Waste Heat Recovery for Hydrogen Production
Jul 2021
Publication
Water electrolysis based on solid oxide electrolysis cell (SOEC) exhibits high conversion efficiency due to part of energy demand can be derived from thermal energy. Therefore it can be integrated with other sources of thermal energy to reduce the consumption of electrical energy. In this paper a diesel engine is integrated with the SOEC stacks for heat recovery steam generator (HRSG). The thermal energy from the engine exhaust gas used to heat the inlet H2O of the SOEC is carried out as the integration case. A SOEC plant using electricity as the thermal heat input is selected as the base case. Thermodynamic analysis of the benchmark and integration scheme reveals that an electrical efficiency of 73.12% and 85.17% can be achieved respectively. The diesel to power efficiency can be increased to 70% when the exhaust gas is completely utilized by the SOEC system. The impacts of some key parameters including current density and operating temperature on system performance have also been conducted and found that the system has optimized parameters of current density and operating temperature to achieve better performance.
Hydrogen vs. Batteries: Comparative Safety Assessments for a High-Speed Passenger Ferry
Mar 2022
Publication
Batteries and hydrogen constitute two of the most promising solutions for decarbonising international shipping. This paper presents the comparison between a battery and a proton-exchange membrane hydrogen fuel cell version of a high-speed catamaran ferry with a main focus on safety. The systems required for each version are properly sized and fitted according to the applicable rules and their impact on the overall design is discussed. Hazards for both designs were identified; frequency and consequence indexes for them were input qualitatively following Novel Technology Qualification and SOLAS Alternative Designs and Arrangements while certain risk control options were proposed in order to reduce the risks of the most concerned accidental events. The highest ranked risks were analysed by quantitative risk assessments in PyroSim software. The gas dispersion analysis performed for the hydrogen version indicated that it is crucial for the leakage in the fuel cell room to be stopped within 1 s after being detected to prevent the formation of explosive masses under full pipe rupture of 33 mm diameter even with 120 air changes per hour. For the battery version the smoke/fire simulation in the battery room indicated that the firefighting system could achieve a 30% reduction in fire duration with firedoors closed and ventilation shut compared to the scenario without a firefighting system.
Opportunities for Low-carbon Generation and Storage Technologies to Decarbonise the Future Power System
Feb 2023
Publication
Alternatives to cope with the challenges of high shares of renewable electricity in power systems have been addressed from different approaches such as energy storage and low-carbon technologies. However no model has previously considered integrating these technologies under stability requirements and different climate conditions. In this study we include this approach to analyse the role of new technologies to decarbonise the power system. The Spanish power system is modelled to provide insights for future applications in other regions. After including storage and low-carbon technologies (currently available and under development) batteries and hydrogen fuel cells have low penetration and the derived emission reduction is negligible in all scenarios. Compressed air storage would have a limited role in the short term but its performance improves in the long term. Flexible generation technologies based on hydrogen turbines and long-duration storage would allow the greatest decarbonisation providing stability and covering up to 11–14 % of demand in the short and long term. The hydrogen storage requirement is equivalent to 18 days of average demand (well below the theoretical storage potential in the region). When these solutions are considered decarbonising the electricity system (achieving Paris targets) is possible without a significant increase in system costs (< € 114/MWh).
Boosting the H2 Production Efficiency via Photocatalytic Organic Reforming: The Role of Additional Hole Scavenging System
Nov 2021
Publication
The simultaneous photocatalytic H2 evolution with environmental remediation over semiconducting metal oxides is a fascinating process for sustainable fuel production. However most of the previously reported photocatalytic reforming showed nonstoichiometric amounts of the evolved H2 when organic substrates were used. To explain the reasons for this phenomenon a careful analysis of the products and intermediates in gas and aqueous phases upon the photocatalytic hydrogen evolution from oxalic acid using Pt/TiO2 was performed. A quadrupole mass spectrometer (QMS) was used for the continuous flow monitoring of the evolved gases while high performance ion chromatography (HPIC) isotopic labeling and electron paramagnetic resonance (EPR) were employed to understand the reactions in the solution. The entire consumption of oxalic acid led to a ~30% lower H2 amount than theoretically expected. Due to the contribution of the photoKolbe reaction mechanism a tiny amount of formic acid was produced then disappeared shortly after the complete consumption of oxalic acid. Nevertheless a much lower concentration of formic acid was generated compared to the nonstoichiometric difference between the formed H2 and the consumed oxalic acid. Isotopic labeling measurements showed that the evolved H2 HD and/or D2 matched those of the solvent; however using D2O decreased the reaction rate. Interestingly the presence of KI as an additional hole scavenger with oxalic acid had a considerable impact on the reaction mechanism and thus the hydrogen yield as indicated by the QMS and the EPR measurements. The added KI promoted H2 evolution to reach the theoretically predictable amount and inhibited the formation of intermediates without affecting the oxalic acid degradation rate. The proposed mechanism by which KI boosts the photocatalytic performance is of great importance in enhancing the overall energy efficiency for hydrogen production via photocatalytic organic reforming.
Optimal Energy Management in a Standalone Microgrid, with Photovoltaic Generation, Short-Term Storage, and Hydrogen Production
Mar 2020
Publication
This paper addresses the energy management of a standalone renewable energy system. The system is configured as a microgrid including photovoltaic generation a lead-acid battery as a short term energy storage system hydrogen production and several loads. In this microgrid an energy management strategy has been incorporated that pursues several objectives. On the one hand it aims to minimize the amount of energy cycled in the battery in order to reduce the associated losses and battery size. On the other hand it seeks to take advantage of the long-term surplus energy producing hydrogen and extracting it from the system to be used in a fuel cell hybrid electric vehicle. A crucial factor in this approach is to accommodate the energy consumption to the energy demand and to achieve this a model predictive control (MPC) scheme is proposed. In this context proper models for solar estimation hydrogen production and battery energy storage will be presented. Moreover the controller is capable of advancing or delaying the deferrable loads from its prescheduled time. As a result a stable and efficient supply with a relatively small battery is obtained. Finally the proposed control scheme has been validated on a real case scenario.
Energy Storage Systems: A Review
Jul 2022
Publication
The world is rapidly adopting renewable energy alternatives at a remarkable rate to address the ever-increasing environmental crisis of CO2 emissions. Renewable Energy Systems (RES) offers enormous potential to decarbonize the environment because they produce no greenhouse gases or other polluting emissions. However the RES relies on natural resources for energy generation such as sunlight wind water geothermal which are generally unpredictable and reliant on weather season and year. To account for these intermittencies renewable energy can be stored using various techniques and then used in a consistent and controlled manner as needed. Several researchers from around the world have made substantial contributions over the last century to developing novel methods of energy storage that are efficient enough to meet increasing energy demand and technological break-throughs. This review attempts to provide a critical review of the advancements in the Energy Storage System (ESS) from 1850–2022 including its evolution classification operating principles and comparison
Study of Heat Loss Mechanism in Argon-circulated Hydrogen Engine Combustion Chamber Wall Surface Conditions
Jul 2022
Publication
Hydrogen fuel in internal combustion engine gives a very big advantage to the transportation sector especially in solving the greenhouse emission problem. However there are only few research discovered the ability of argon as a working gas in hydrogen combustion in internal combustion engine. The high temperature rises from the argon compression tend to result in heat loss problem. This research aims to study the heat loss mechanism on wall surface condition in the combustion chamber. Experiments were conducted to study the effects of different heat flux sensor locations and the effect of ignition delay on heat flux. Local heat flux measurement was collected and images were observed using high speed shadowgraph images. The ignition delay that occurred near the combustion wall will result in larger heat loss throughout the combustion process. Higher ambient pressure results in a bigger amount of heat flux value. Other fundamental characteristics were obtained and discussed which may help in contributing the local heat loss data of an argon-circulated hydrogen engine in future engine operation.
No more items...