Applications & Pathways
Hybrid Power-heat Microgrid Solution Using Hydrogen as an Energy Vector for Residential Houses in Spain. A Case Study
May 2022
Publication
In order to favor a transition to a renewable energy economy it is necessary to study the possible permeation of renewable energy sources not only in the electric grid or industrial scale but also in the small householding scale. One of the most interesting technologies available for this purpose is solar energy since it is a mature technology that can be easily installed in every rooftop. Thus a techno-economic assessment was carried out to evaluate the installation of a solar-based power-heat hybrid microgrid considering the use of hydrogen as an energy vector in a typical residential house in Spain. Lead-acid batteries plus the photovoltaic and solar thermal energy installation are complemented with a hydrogen system composed of an electrolyzer two metal hydride bottles and a fuel cell. A simulation tool has been generated using experimental models developed and validated with real equipment for each one of the electric microgrid component. Three operating modes were tested making use of this tool to better manage the energy consumed/produced and optimize the economic output of the facility. The results show that setting up a hydrogen-based microgrid in a residential house is unviable today mainly due to the high cost of hydrogen generation and consumption equipment. If only solar energy is considered the microgrid inversion (12.500 €) is recovered in ten years. On the other hand selling the electricity output has almost no repercussions considering current electrical rates in Spain. Finally while using an optimization algorithm to manage energy use battery life-spam and economic benefit slightly increase. However this profit may not be enough to justify the use of a more complex control system. The results of this research will help users renewable energy companies investigators and policymakers to better understand the different factors influencing the spread of renewable smart grids in households and propose solutions to address these.
Production of High-purity Hydrogen from Paper Recycling Black Liquor via Sorption Enhanced Steam Reforming
Jul 2020
Publication
Environmentally friendly and energy saving treatment of black liquor (BL) a massively produced waste in Kraft papermaking process still remains a big challenge. Here by adopting a Ni-CaO-Ca12Al14O33 bifunctional catalyst derived from hydrotalcite-like materials we demonstrate the feasibility of producing high-purity H2 (∼96%) with 0.9 mol H2 mol-1 C yield via the sorption enhanced steam reforming (SESR) of BL. The SESRBL performance in terms of H2 production maintained stable for 5 cycles but declined from the 6th cycle. XRD Raman spectroscopy elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst. It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL while deposition of Na and K from the BL might also be responsible for the declined performance. On the other hand it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO3. Our results highlight a promising alternative for BL treatment and H2 production thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.
Effect of Supercharging on Improving Thermal Efficiency and Modifying Combustion Characteristics in Lean-burn Direct-injection Near-zero-emission Hydrogen Engines
Oct 2021
Publication
The authors have proposed a new combustion process called the Plume Ignition Combustion Concept (PCC) in which with an optimal combination of hydrogen injection timing and controlled jet geometry the plume of the hydrogen jet is spark-ignited to accomplish combustion of a rich mixture. This combustion process markedly improves thermal efficiency by reducing cooling loss which is essential for increasing thermal efficiency in a hydrogen engine while maintaining high power. In order to improve thermal efficiency and reduce NOx formation further PCC was applied to a lean-burn regime to burn a leaner mixture globally. In this study the effect of supercharging which was applied to recover the reduced output power due to the leaner mixture on improving thermal efficiency was confirmed along with clarifying the cause.
Patterned Membranes for Proton Exchange Membrane Fuel Cells Working at Low Humidity
Jun 2021
Publication
High performing proton exchange membrane fuel cells (PEMFCs) that can operate at low relative humidity is a continuing technical challenge for PEMFC developers. In this work micro-patterned membranes are demonstrated at the cathode side by solution casting techniques using stainless steel moulds with laser-imposed periodic surface structures (LIPSS). Three types of patterns lotus lines and sharklet are investigated for their influence on the PEMFC power performance at varying humidity conditions. The experimental results show that the cathode electrolyte pattern in all cases enhances the fuel cell power performance at 100% relative humidity (RH). However only the sharklet pattern exhibits a significant improvement at 25% RH where a peak power density of 450 mW cm−2 is recorded compared with 150 mW cm−2 of the conventional flat membrane. The improvements are explored based on high-frequency resistance electrochemically active surface area (ECSA) and hydrogen crossover by in situ membrane electrode assembly (MEA) testing.
A Comparison of Two Hydrogen Storages in a Fossil Free Direct Reduced Iron Process
Jul 2021
Publication
Hydrogen direct reduction has been proposed as a means to decarbonize primary steelmaking. Preferably the hydrogen necessary for this process is produced via water electrolysis. A downside to electrolysis is the large electricity demand. The electricity cost of water electrolysis may be reduced by using a hydrogen storage to exploit variations in electricity price i.e. producing more hydrogen when the electricity price is low and vice versa. In this paper we compare two kinds of hydrogen storages in the context of a hydrogen direct reduction process via simulations based on historic Swedish electricity prices: the storage of gaseous hydrogen in an underground lined rock cavern and the storage of hydrogen chemically bound in methanol. We find the methanol-based storages to be economically advantageous to lined rock caverns in several scenarios. The main advantages of methanol-based storage are the low investment cost of storage capacity and the possibility to decouple storage capacity from rate capacity. Nevertheless no storage option is found to be profitable for historic Swedish electricity prices. For the storages to be profitable electricity prices must be volatile with relatively frequent high peaks which has happened rarely in Sweden in recent years. However such scenarios may become more common with the expected increase of intermittent renewable power in the Swedish electricity system.
Alternative Energy Technologies as a Cultural Endeavor: A Case Study of Hydrogen and Fuel Cell Development in Germany
Feb 2012
Publication
Background: The wider background to this article is the shift in the energy paradigm from fossil energy sources to renewable sources which should occur in the twenty-first century. This transformation requires the development of alternative energy technologies that enable the deployment of renewable energy sources in transportation heating and electricity. Among others hydrogen and fuel cell technologies have the potential to fulfill this requirement and to contribute to a sustainable and emission-free transport and energy system. However whether they will ever reach broad societal acceptance will not only depend on technical issues alone. The aim of our study is to reveal the importance of nontechnical issues. Therefore the article at hand presents a case study of hydrogen and fuel cells in Germany and aims at highlighting the cultural context that affects their development.<br/>Methods: Our results were obtained from a rich pool of data generated in various research projects through more than 30 in-depth interviews direct observations and document analyses.<br/>Results: We found that individual and collective actors developed five specific supportive practices which they deploy in five diverse arenas of meaning in order to attach certain values to hydrogen and fuel cell technologies.<br/>Conclusions: Based on the results we drew more general conclusions and deducted an overall model for the analysis of culture in technological innovations that is outlined at the end of the article. It constitutes our contribution to the interdisciplinary collaboration required for tackling the shift in this energy paradigm.
Modeling of Fixed Bed Reactor for Coal Tar Hydrogenation via the Kinetic Lumping Approach
Nov 2018
Publication
Hydrogenation technology is an indispensable chemical upgrading process for converting the heavy feedstock into favorable lighter products. In this work a new kinetic model containing four hydrocarbon lumps (feedstock diesel gasoline cracking gas) was developed to describe the coal tar hydrogenation process the Levenberg–Marquardt’s optimization algorithm was used to determine the kinetic parameters by minimizing the sum of square errors between experimental and calculated data the predictions from model validation showed a good agreement with experimental values. Subsequently an adiabatic reactor model based on proposed lumped kinetic model was constructed to further investigate the performance of hydrogenation fixed-bed units the mass balance and energy balance within the phases in the reactor were taken into accounts in the form of ordinary differential equation. An application of the reactor model was performed for simulating the actual bench-scale plant of coal tar hydrogenation the simulated results on the products yields and temperatures distribution along with the reactor are shown to be good consistent with the experimental data.
Conceptual Design of a Hybrid Hydrogen Fuel Cell/Battery Blended-Wing-Body Unmanned Aerial Vehicle—An Overview
May 2022
Publication
The manuscript presents the conceptual design phase of an unmanned aerial vehicle with the objective of a systems approach towards the integration of a hydrogen fuel-cell system and Li-ion batteries into an aerodynamically efficient platform representative of future aircraft configurations. Using a classical approach to aircraft design and a combination of low- and high-resolution computational simulations a final blended wing body UAV was designed with a maximum take-off weight of 25 kg and 4 m wingspan. Preliminary aerodynamic and propulsion sizing demonstrated that the aircraft is capable of completing a 2 h long mission powered by a 650 W fuel cell hybridized with a 100 Wh battery pack and with a fuel quantity of 80 g of compressed hydrogen.
Research on Hydrogen Consumption and Driving Range of Hydrogen Fuel Cell Vehicle under the CLTC-P Condition
Dec 2021
Publication
Hydrogen consumption and mileage are important economic indicators of fuel cell vehicles. Hydrogen consumption is the fundamental reason that restricts mileage. Since there are few quantitative studies on hydrogen consumption during actual vehicle operation the high cost of hydrogen consumption in outdoor testing makes it impossible to guarantee the accuracy of the test. Therefore this study puts forward a test method based on the hydrogen consumption of fuel cell vehicles under CLTC-P operating conditions to test the hydrogen consumption of fuel cell vehicles per 100 km. Finally the experiment shows that the mileage calculated by hydrogen consumption has a higher consistency with the actual mileage. Based on this hydrogen consumption test method the hydrogen consumption can be accurately measured and the test time and cost can be effectively reduced.
Hydrogenation Production via Chemical Looping Reforming of Coke Oven Gas
Jun 2020
Publication
Coke oven gas (COG) is one of the most important by-products in the steel industry and the conversion of COG to value-added products has attracted much attention from both economic and environmental views. In this work we apply the chemical looping reforming technology to produce pure H2 from COG. A series of La1-xSrxFeO3 (x = 0 0.2 0.3 0.4 0.5 0.6) perovskite oxides were prepared as oxygen carriers for this purpose. The reduction behaviours of La1-xSrxFeO3 perovskite by different reducing gases (H2 CO CH4 and the mixed gases) are investigated to discuss the competition effect of different components in COG for reacting with the oxygen carriers. The results show that reduction temperatures of H2 and CO are much lower than that of CH4 and high temperatures (>800 °C) are requested for selective oxidation of methane to syngas. The co-existence of CO and H2 shows weak effect on the equilibrium of methane conversion at high temperatures but the oxidation of methane to syngas can inhibit the consumption of CO and H2. The doping of suitable amounts of Sr in LaFeO3 perovskite (e.g. La0.5Sr0.5FeO3) significantly promotes the reactivity for selective oxidation of methane to syngas and inhibits the formation of carbon deposition obtaining both high methane conversion in the COG oxidation step and high hydrogen yield in the water splitting step. The La0.5Sr0.5FeO3 shows the highest methane conversion (67.82%) hydrogen yield (3.34 mmol·g-1) and hydrogen purity (99.85%). The hydrogen yield in water splitting step is treble as high as the hydrogen consumption in reduction step. These results reveal that chemical looping reforming of COG to produce pure H2 is feasible and an O2-assistant chemical looping reforming process can further improve the redox stability of oxygen carrier.
Modelling and Designing Cryogenic Hydrogen Tanks for Future Aircraft Applications
Jan 2018
Publication
In the near future the challenges to reduce the economic and social dependency on fossil fuels must be faced increasingly. A sustainable and efficient energy supply based on renewable energies enables large-scale applications of electro-fuels for e.g. the transport sector. The high gravimetric energy density makes liquefied hydrogen a reasonable candidate for energy storage in a light-weight application such as aviation. Current aircraft structures are designed to accommodate jet fuel and gas turbines allowing a limited retrofitting only. New designs such as the blended-wing-body enable a more flexible integration of new storage technologies and energy converters e.g. cryogenic hydrogen tanks and fuel cells. Against this background a tank-design model is formulated which considers geometrical mechanical and thermal aspects as well as specific mission profiles while considering a power supply by a fuel cell. This design approach enables the determination of required tank mass and storage density respectively. A new evaluation value is defined including the vented hydrogen mass throughout the flight enabling more transparent insights on mass shares. Subsequently a systematic approach in tank partitioning leads to associated compromises regarding the tank weight. The analysis shows that cryogenic hydrogen tanks are highly competitive with kerosene tanks in terms of overall mass which is further improved by the use of a fuel cell.
Testing Programme for Hydrogen Tolerance Tests of Domestic and Commercial Natural Gas Appliances
Jan 2021
Publication
The THyGA project (‘Testing Hydrogen admixture for Gas Applications’) focusses on technical aspects and the regulatory framework concerning the potential operation of domestic and commercial end-user appliances with hydrogen / natural gas blends.<br/>The core of the project is a broad experimental campaign with the aim to conduct up to 100 hydrogen tolerance tests. In addition the technical status quo and present knowledge about hydrogen impact on domestic and commercial appliances are assessed and potential future developments of rules and standards are discussed. Also mitigation strategies for coping with high levels of hydrogen admixture will be developed. By this broad approach the project aims at investigating which levels of hydrogen blending impact the various appliance technologies and to which extent in order to identify the regime in which a safe efficient and low-polluting operation is possible.<br/>The series of public reports by the THyGA project starts with several publications from work package 2 which sets the basis for the upcoming results and discussion of the experimental campaign as well as mitigation and standardisation topics.<br/>This report D2.5 completes the series of public reports from work package 2. It explains the steps of development of the test programme for gas-fired appliance tests with hydrogen admixture and especially describes the exchange between the THyGA partners and the external stakeholders.<br/>The report also explains the process of acquisition of appliances to test and method of selecting appliances.
Modelling and Analyzing the Impact of Hydrogen Enriched Natural Gas on Domestic Gas Boilers in a Decarbonization Perspective
Aug 2020
Publication
Decarbonization of energy economy is nowadays a topical theme and several pathways are under discussion. Gaseous fuels have a fundamental role for this transition and the production of low carbon-impact fuels is necessary to deal with this challenge. The generation of renewable hydrogen is a trusted solution since this energy vector can be promptly produced from electricity and injected into the existing natural gas infrastructure granting storage capacity and easy transportation. This scenario will lead in the near future to hydrogen enrichment of natural gas whose impact on the infrastructures is being actively studied. The effect on end-user devices such as domestic gas boilers instead is still little analyzed and tested but is fundamental to be assessed. The aim of this research is to generate knowledge on the effect of hydrogen enrichment on the widely used premixed boilers: the investigations include pollutant emissions efficiency flashback and explosion hazard control system and materials selection. A model for calculating several parameters related to combustion of hydrogen enriched natural gas is presented. Guidelines for the design of new components are provided and an insight is given on the maximum hydrogen blending bearable by the current boilers.
Optimal Synergy between Photovoltaic Panels and Hydrogen Fuel Cells for Green Power Supply of a Green Building—A Case Study
Jun 2021
Publication
Alternative energy resources have a significant function in the performance and decarbonization of power engendering schemes in the building application domain. Additionally “green buildings” play a special role in reducing energy consumption and minimizing CO2 emissions in the building sector. This research article analyzes the performance of alternative primary energy sources (sun and hydrogen) integrated into a hybrid photovoltaic panel/fuel cell system and their optimal synergy to provide green energy for a green building. The study addresses the future hydrogen-based economy which involves the supply of hydrogen as the fuel needed to provide fuel cell energy through a power distribution infrastructure. The objective of this research is to use fuel cells in this field and to investigate their use as a green building energy supply through a hybrid electricity generation system which also uses photovoltaic panels to convert solar energy. The fuel cell hydrogen is supplied through a distribution network in which hydrogen production is outsourced and independent of the power generation system. The case study creates virtual operating conditions for this type of hybrid energy system and simulates its operation over a one-year period. The goal is to demonstrate the role and utility of fuel cells in virtual conditions by analyzing energy and economic performance indicators as well as carbon dioxide emissions. The case study analyzes the optimal synergy between photovoltaic panels and fuel cells for the power supply of a green building. In the simulation an optimally configured hybrid system supplies 100% of the energy to the green building while generating carbon dioxide emissions equal to 11.72% of the average value calculated for a conventional energy system providing similar energy to a standard residential building. Photovoltaic panels account for 32% of the required annual electricity production and the fuel cells generate 68% of the total annual energy output of the system.
Gas Transition: Renewable Hydrogen’s Future in Eastern Australia’s Energy Networks
Jul 2021
Publication
The energy transition for a net-zero future will require deep decarbonisation that hydrogen is uniquely positioned to facilitate. This technoeconomic study considers renewable hydrogen production transmission and storage for energy networks using the National Electricity Market (NEM) region of Eastern Australia as a case study. Plausible growth projections are developed to meet domestic demands for gas out to 2040 based on industry commitments and scalable technology deployment. Analysis using the discounted cash flow technique is performed to determine possible levelised cost figures for key processes out to 2050. Variables include geographic limitations growth rates and capacity factors to minimise abatement costs compared to business-as-usual natural gas forecasts. The study provides an optimistic outlook considering renewable power-to-X opportunities for blending replacement and gas-to-power to show viable pathways for the gas transition to green hydrogen. Blending is achievable with modest (3%) green premiums this decade and substitution for natural gas combustion in the long-term is likely to represent an abatement cost of AUD 18/tCO2-e including transmission and storage.
Numerical Evaluation of the Effect of Fuel Blending with CO2 and H2 on the Very Early Corona‐Discharge Behavior in Spark Ignited Engines
Feb 2022
Publication
Reducing green‐house gases emission from light‐duty vehicles is compulsory in order to slow down the climate change. The application of High Frequency Ignition systems based on the Corona discharge effect has shown the potential to extend the dilution limit of engine operating conditions promoting lower temperatures and faster combustion events thus higher thermal and indicating efficiency. Furthermore predicting the behavior of Corona ignition devices against new sustainable fuel blends including renewable hydrogen and biogas is crucial in order to deal with the short‐intermediate term fleet electric transition. The numerical evaluation of Corona‐induced discharge radius and radical species under those conditions can be helpful in order to capture local effects that could be reached only with complex and expensive optical investigations. Using an ex‐ tended version of the Corona one‐dimensional code previously published by the present authors the simulation of pure methane and different methane–hydrogen blends and biogas–hydrogen blends mixed with air was performed. Each mixture was simulated both for 10% recirculated exhaust gas dilution and for its corresponding dilute upper limit which was estimated by means of chemical kinetics simulations integrated with a custom misfire detection criterion.
A General Vision for Reduction of Energy Consumption and CO2 Emissions from the Steel Industry
Aug 2020
Publication
The 2018 IPCC (The Intergovernmental Panel on Climate Change’s) report defined the goal to limit global warming to 1.5 ◦C by 2050. This will require “rapid and far-reaching transitions in land energy industry buildings transport and cities”. The challenge falls on all sectors especially energy production and industry. In this regard the recent progress and future challenges of greenhouse gas emissions and energy supply are first briefly introduced. Then the current situation of the steel industry is presented. Steel production is predicted to grow by 25–30% by 2050. The dominant iron-making route blast furnace (BF) especially is an energy-intensive process based on fossil fuel consumption; the steel sector is thus responsible for about 7% of all anthropogenic CO2 emissions. In order to take up the 2050 challenge emissions should see significant cuts. Correspondingly specific emissions (t CO2/t steel) should be radically decreased. Several large research programs in big steelmaking countries and the EU have been carried out over the last 10–15 years or are ongoing. All plausible measures to decrease CO2 emissions were explored here based on the published literature. The essential results are discussed and concluded. The specific emissions of “world steel” are currently at 1.8 t CO2/t steel. Improved energy efficiency by modernizing plants and adopting best available technologies in all process stages could decrease the emissions by 15–20%. Further reductions towards 1.0 t CO2/t steel level are achievable via novel technologies like top gas recycling in BF oxygen BF and maximal replacement of coke by biomass. These processes are however waiting for substantive industrialization. Generally substituting hydrogen for carbon in reductants and fuels like natural gas and coke gas can decrease CO2 emissions remarkably. The same holds for direct reduction processes (DR) which have spread recently exceeding 100 Mt annual capacity. More radical cut is possible via CO2 capture and storage (CCS). The technology is well-known in the oil industry; and potential applications in other sectors including the steel industry are being explored. While this might be a real solution in propitious circumstances it is hardly universally applicable in the long run. More auspicious is the concept that aims at utilizing captured carbon in the production of chemicals food or fuels e.g. methanol (CCU CCUS). The basic idea is smart but in the early phase of its application the high energy-consumption and costs are disincentives. The potential of hydrogen as a fuel and reductant is well-known but it has a supporting role in iron metallurgy. In the current fight against climate warming H2 has come into the “limelight” as a reductant fuel and energy storage. The hydrogen economy concept contains both production storage distribution and uses. In ironmaking several research programs have been launched for hydrogen production and reduction of iron oxides. Another global trend is the transfer from fossil fuel to electricity. “Green” electricity generation and hydrogen will be firmly linked together. The electrification of steel production is emphasized upon in this paper as the recycled scrap is estimated to grow from the 30% level to 50% by 2050. Finally in this review all means to reduce specific CO2 emissions have been summarized. By thorough modernization of production facilities and energy systems and by adopting new pioneering methods “world steel” could reach the level of 0.4–0.5 t CO2/t steel and thus reduce two-thirds of current annual emissions.
A Hot Syngas Purification System Integrated with Downdraft Gasification of Municipal Solid Waste
Jan 2019
Publication
Gasification of municipal solid waste (MSW) with subsequent utilization of syngas in gas engines/turbines and solid oxide fuel cells can substantially increase the power generation of waste-to-energy facilities and optimize the utilization of wastes as a sustainable energy resources. However purification of syngas to remove multiple impurities such as particulates tar HCl alkali chlorides and sulfur species is required. This study investigates the feasibility of high temperature purification of syngas from MSW gasification with the focus on catalytic tar reforming and desulfurization. Syngas produced from a downdraft fixed-bed gasifier is purified by a multi-stage system. The system comprises of a fluidized-bed catalytic tar reformer a filter for particulates and a fixed-bed reactor for dechlorination and then desulfurization with overall downward cascading of the operating temperatures throughout the system. Novel nano-structured nickel catalyst supported on alumina and regenerable Ni-Zn desulfurization sorbent loaded on honeycomb are synthesized. Complementary sampling and analysis methods are applied to quantify the impurities and determine their distribution at different stages. Experimental and thermodynamic modeling results are compared to determine the kinetic constraints in the integrated system. The hot purification system demonstrates up to 90% of tar and sulfur removal efficiency increased total syngas yield (14%) and improved cold gas efficiency (12%). The treated syngas is potentially applicable in gas engines/turbines and solid oxide fuel cells based on the dew points and concentration limits of the remaining tar compounds. Reforming of raw syngas by nickel catalyst for over 20 h on stream shows strong resistance to deactivation. Desulfurization of syngas from MSW gasification containing significantly higher proportion of carbonyl sulfide than hydrogen sulfide traces of tar and hydrogen chloride demonstrates high performance of Ni-Zn sorbents.
An Overview of the Classification, Production and Utilization of Biofuels for Internal Combustion Engine Applications
Sep 2021
Publication
Biofuel a cost-effective safe and environmentally benign fuel produced from renewable sources has been accepted as a sustainable replacement and a panacea for the damaging effects of the exploration for and consumption of fossil-based fuels. The current work examines the classification generation and utilization of biofuels particularly in internal combustion engine (ICE) applications. Biofuels are classified according to their physical state technology maturity the generation of feedstock and the generation of products. The methods of production and the advantages of the application of biogas bioalcohol and hydrogen in spark ignition engines as well as biodiesel Fischer– Tropsch fuel and dimethyl ether in compression ignition engines in terms of engine performance and emission are highlighted. The generation of biofuels from waste helps in waste minimization proper waste disposal and sanitation. The utilization of biofuels in ICEs improves engine performance and mitigates the emission of poisonous gases. There is a need for appropriate policy frameworks to promote commercial production and seamless deployment of these biofuels for transportation applications with a view to guaranteeing energy security.
A Review of Synthetic Fuels for Passenger Vehicles
May 2019
Publication
Synthetic fuels produced with renewable surplus electricity depict an interesting solution for the decarbonization of mobility and transportation applications which are not suited for electrification. With the objective to compare various synthetic fuels an analysis of all the energy conversion steps is conducted from the electricity source i.e. wind- solar- or hydro-power to the final application i.e. a vehicle driving a certain number of miles. The investigated fuels are hydrogen methane methanol dimethyl ether and Diesel. While their production process is analyzed based on literature the usage of these fuels is analyzed based on chassis dynanometer measurement data of various EURO-6b passenger vehicles. Conventional and hybrid power-trains as well as various carbon dioxide sources are investigated in two scenarios. The first reference scenario considers market-ready technology only while the second future scenario considers technology which is currently being developed in industry and assumed to be market-ready in near future. With the results derived in this study and with consideration of boundary conditions i.e. availability of infrastructure storage technology of gaseous fuels energy density requirements etc. the most energy efficient of the corresponding suitable synthetic fuels can be chosen.
Environmental and Energy Life Cycle Analyses of Passenger Vehicle Systems Using Fossil Fuel-derived Hydrogen
Sep 2021
Publication
Hydrogen energy utilization is expected due to its environmental and energy efficiencies. However many issues remain to be solved in the social implementation of hydrogen energy through water electrolysis. This analyzes and compares the energy consumption and GHG emissions of fossil fuel-derived hydrogen and gasoline energy systems over their entire life cycle. The results demonstrate that for similar vehicle weights the hydrogen energy system consumes 1.8 MJ/km less energy and emits 0.15 kg-CO 2 eq./km fewer GHG emissions than those of the gasoline energy system. Hydrogen derived from fossil fuels may contribute to future energy systems due to its stable energy supply and economic efficiency. Lowering the power source carbon content also improved the environmental and energy efficiencies of hydrogen energy derived from fossil fuels.
Development and Comparison of the Test Methods Proposed in the Chinese Test Specifications for Fuel Cell Electric Vehicles
Feb 2022
Publication
Fuel cell electric vehicles are generally considered to have broad development prospects due to their high efficiency and zero emissions. The governments of the United States Japan the European Union and China are taking action to promote the development of the industry. In 2020 China launched a fuel cell electric vehicle demonstration project and there will be 30∼50 thousand FCEVs included in this project by the end of 2025. How to standardize the consistency of data and develop a unified and accurate evaluation method is an important topic. The difficulty is how to keep balance among scientificity neutrality and feasibility in the evaluation method. In order to evaluate the performance of vehicles in demonstration operation projects China has issued the "Fuel Cell Electric Vehicle Test Specifications" which is an important guide for the future development of fuel cell electric vehicles in China. This paper compares the test methods for critical parameters in this specifications with those used in the United States and Japan. It explains China’s technical considerations in detail including fuel cell system rated power the volume power density of the fuel cell stack fuel cell system specific power fuel cell system sub-zero cold start and fuel cell electric vehicle range contributed by hydrogen. For the volume power density of the fuel cell stack as an example both the US Department of Energy and Japan’s New Energy and Industrial Technology Development Organization have proposed technical goals. However the lack of specific and detailed test methods has confused the industry. We propose a new test method using bipolar plate measurement based on scientificity feasibility and neutrality This is the first time to define the measuring method of the volume and specific power density of the fuel cell stack. For sub-zero cold start we put forward a feasible scheme for sub-zero cold start at the system level. For range contributed by hydrogen we propose a new test method that can distinguish the contributing of electric and hydrogen energy. Furthermore a hydrogen-to-electric conversion formula is proposed to calculate the equivalent hydrogen consumption which makes it possible to compare the energy consumption between plug-in and non-plug-in vehicles. At the same time this approach is significant in helping fuel cell-related enterprises to understand the formulation of China’s “Fuel Cell Electric Vehicle Test Specifications”. It should also be helpful for guiding product design and predicting fuel cell electric vehicle policy direction in China.
Low Carbon Scenario Analysis of a Hydrogen-Based Energy Transition for On-Road Transportation in California
Nov 2021
Publication
Fuel cell electric vehicles (FCEV) are emerging as one of the prominent zero emission vehicle technologies. This study follows a deterministic modeling approach to project two scenarios of FCEV adoption and the resulting hydrogen demand (low and high) up to 2050 in California using a transportation transition model. The study then estimates the number of hydrogen production and refueling facilities required to meet demand. The impact of system scale-up and learning rates on hydrogen price is evaluated using standalone supply chain models: H2A HDSAM HRSAM and HDRSAM. A sensitivity analysis explores key factors that affect hydrogen prices. In the high scenario light and heavy-duty fuel cell vehicle stocks reach 12.5 million and 1 million by 2050 respectively. The resulting annual hydrogen demand is 3.9 billion kg making hydrogen the dominant transportation fuel. Satisfying such high future demands will require rapid increases in infrastructure investments starting now but especially after 2030 when there is an exponential increase in the number of production plants and refueling stations. In the long term electrolytic hydrogen delivered using dedicated hydrogen pipelines to larger stations offers substantial cost savings. Feedstock prices size of the hydrogen market and station utilization are the prominent parameters that affect hydrogen price.
Optimal Scheduling of a Hydrogen-Based Energy Hub Considering a Stochastic Multi-Attribute Decision-Making Approach
Jan 2023
Publication
Nowadays the integration of multi-energy carriers is one of the most critical matters in smart energy systems with the aim of meeting sustainable energy development indicators. Hydrogen is referred to as one of the main energy carriers in the future energy industry but its integration into the energy system faces different open challenges which have not yet been comprehensively studied. In this paper a novel day-ahead scheduling is presented to reach the optimal operation of a hydrogen-based energy hub based on a stochastic multi-attribute decision-making approach. In this way the energy hub model is first developed by providing a detailed model of Power-to-Hydrogen (P2H) facilities. Then a new multi-objective problem is given by considering the prosumer’s role in the proposed energy hub model as well as the integrated demand response program (IDRP). The proposed model introduces a comprehensive approach from the analysis of the historical data to the final decision-making with the aim of minimizing the system operation cost and carbon emission. Moreover to deal with system uncertainty the scenario-based method is applied to model the renewable energy resources fluctuation. The proposed problem is defined as mixed-integer non-linear programming (MINLP) and to solve this problem a simple augmented e-constrained (SAUGMECON) method is employed. Finally the simulation of the proposed model is performed on a case study and the obtained results show the effectiveness and benefits of the proposed scheme.
Public Acceptance for the Implementation of Hydrogen Self-refueling Stations
Sep 2021
Publication
The utilization of hydrogen energy is important for achieving a low-carbon society. Japan has set ambitious goals for hydrogen stations and fuel cell vehicles focusing on the introduction and dissemination of self-refuelling systems. This paper evaluates public trust in the fuel equipment and self-handling technology related to self-refuelling hydrogen stations and compares it with that for widespread gasoline stations. To this end the results of an online survey of 300 people with Japanese driver licenses are reported and analyzed. The results show that trust in the equipment and self-handling is more important for the user than trust in the fuel. In addition to introduce and disseminate new technology such as hydrogen stations users must be made aware of the risk of using the technology until it becomes as familiar as existing gasoline station technology.
An Overview of Promising Alternative Fuels for Road, Rail, Air, and Inland Waterway Transport in Germany
Feb 2022
Publication
To solve the challenge of decarbonizing the transport sector a broad variety of alternative fuels based on different concepts including Power-to-Gas and Power-to-Liquid and propulsion systems have been developed. The current research landscape is investigating either a selection of fuel options or a selection of criteria a comprehensive overview is missing so far. This study aims to close this gap by providing a holistic analysis of existing fuel and drivetrain options spanning production to utilization. For this purpose a case study for Germany is performed considering different vehicle classes in road rail inland waterway and air transport. The evaluated criteria on the production side include technical maturity costs as well as environmental impacts whereas on the utilization side possible blending with existing fossil fuels and the satisfaction of the required mission ranges are evaluated. Overall the fuels and propulsion systems Methanol-to-Gasoline Fischer–Tropsch diesel and kerosene hydrogen battery-electric propulsion HVO DME and natural gas are identified as promising future options. All of these promising fuels could reach near-zero greenhouse gas emissions bounded to some mandatory preconditions. However the current research landscape is characterized by high insecurity with regard to fuel costs depending on the predicted range and length of value chains.
Fuel Cell Power Systems for Maritime Applications: Progress and Perspectives
Jan 2021
Publication
Fuel cells as clean power sources are very attractive for the maritime sector which is committed to sustainability and reducing greenhouse gas and atmospheric pollutant emissions from ships. This paper presents a technological review on fuel cell power systems for maritime applications from the past two decades. The available fuels including hydrogen ammonia renewable methane and methanol for fuel cells under the context of sustainable maritime transportation and their pre-processing technologies are analyzed. Proton exchange membrane molten carbonate and solid oxide fuel cells are found to be the most promising options for maritime applications once energy efficiency power capacity and sensitivity to fuel impurities are considered. The types layouts and characteristics of fuel cell modules are summarized based on the existing applications in particular industrial or residential sectors. The various research and demonstration projects of fuel cell power systems in the maritime industry are reviewed and the challenges with regard to power capacity safety reliability durability operability and costs are analyzed. Currently power capacity costs and lifetime of the fuel cell stack are the primary barriers. Coupling with batteries modularization mass production and optimized operating and control strategies are all important pathways to improve the performance of fuel cell power systems.
The European Green Deal
Dec 2019
Publication
Climate change and environmental degradation are an existential threat to Europe and the world. To overcome these challenges Europe needs a new growth strategy that will transform the Union into a modern resource-efficient and competitive economy where
The European Green Deal is our plan to make the EU's economy sustainable. We can do this by turning climate and environmental challenges into opportunities and making the transition just and inclusive for all
The European Green Deal provides an action plan to
The EU aims to be climate neutral in 2050. We proposed a European Climate Law to turn this political commitment into a legal obligation.
Reaching this target will require action by all sectors of our economy including
The EU will also provide financial support and technical assistance to help those that are most affected by the move towards the green economy. This is called the Just Transition Mechanism. It will help mobilise at least €100 billion over the period 2021-2027 in the most affected regions.
- there are no net emissions of greenhouse gases by 2050
- economic growth is decoupled from resource use
- no person and no place is left behind
The European Green Deal is our plan to make the EU's economy sustainable. We can do this by turning climate and environmental challenges into opportunities and making the transition just and inclusive for all
The European Green Deal provides an action plan to
- boost the efficient use of resources by moving to a clean circular economy
- restore biodiversity and cut pollution
The EU aims to be climate neutral in 2050. We proposed a European Climate Law to turn this political commitment into a legal obligation.
Reaching this target will require action by all sectors of our economy including
- investing in environmentally-friendly technologies
- supporting industry to innovate
- rolling out cleaner cheaper and healthier forms of private and public transport
- decarbonising the energy sector
- ensuring buildings are more energy efficient
- working with international partners to improve global environmental standards
The EU will also provide financial support and technical assistance to help those that are most affected by the move towards the green economy. This is called the Just Transition Mechanism. It will help mobilise at least €100 billion over the period 2021-2027 in the most affected regions.
Thermodynamic Modeling of Hydrogen Refueling for Heavy-duty Fuel Cell Buses and Comparison with Aggregated Real Data
Apr 2021
Publication
The foreseen uptake of hydrogen mobility is a fundamental step towards the decarbonization of the transport sector. Under such premises both refuelling infrastructure and vehicles should be deployed together with improved refuelling protocols. Several studies focus on refuelling the light-duty vehicles with 10 kgH2 up to 700 bar however less known effort is reported for refuelling heavy-duty vehicles with 30–40 kgH2 at 350 bar. The present study illustrates the application of a lumped model to a fuel cell bus tank-to-tank refuelling event tailored upon the real data acquired in the 3Emotion Project. The evolution of the main refuelling quantities such as pressure temperature and mass flow are predicted dynamically throughout the refuelling process as a function of the operating parameters within the safety limits imposed by SAE J2601/2 technical standard. The results show to refuel the vehicle tank from half to full capacity with an Average Pressure Ramp Rate (APRR) equal to 0.03 MPa/s are needed about 10 min. Furthermore it is found that the effect of varying the initial vehicle tank pressure is more significant than changing the ambient temperature on the refuelling performances. In conclusion the analysis of the effect of different APRR from 0.03 to 0.1 MPa/s indicate that is possible to safely reduce the duration of half-to-full refuelling by 62% increasing the APRR value from 0.03 to 0.08 MPa/s.
CO2 Emissions Reduction Measures for RO-RO Vessels on Non-Profitable Coastal Liner Passenger Transport
Jun 2021
Publication
Reducing CO2 emissions from ships in unprofitable coastline transport using electricity and hydrogen has potential for island development to improve transport and protect biodiversity and nature. New technologies are a challenge for shipping companies and their introduction should be accompanied by a system of state aid for alternative energy sources. The energy requirements of an electric ferry for a route of up to 6 km were considered as well as the amount of hydrogen needed to generate the electricity required to charge the ferry batteries to enable a state aid scheme. For a daily ferry operation a specific fuel consumption of 60.6 g/kWh of liquid hydrogen is required in the system fuel cell with a total of 342.69 kg of hydrogen. Compared to marine diesel the use of electric ferries leads to a reduction of CO2 emissions by up to 90% including significantly lower NOx Sox and particulate matter (PM) emissions and operating costs by up to 80%.
Transport Pathway to Hydrogen webinar
Mar 2021
Publication
Webinar to accompany the launch of the Cadent Future Role of Gas in Transport report which can be found here
Decarbonising UK Transport: Implications for Electricity Generation, Land Use and Policy
Dec 2022
Publication
To ensure the UK’s net zero targets are met the transition from conventionally fueled transport to low emission alternatives is necessary. The impact from increased decarbonised electricity generation on ecosystem services (ES) and natural capital (NC) are not currently quantified with decarbonisation required to minimise impacts from climate change. This study aims to project the future electric and hydrogen energy demand between 2020 and 2050 for car bus and train to better understand the land/sea area that would be required to support energy generation. In this work predictions of the geospatial impact of renewable energy (onshore/offshore wind and solar) nuclear and fossil fuels on ES and NC were made considering generation mix number of generation installations and energy density. Results show that electric transport will require ~136599 GWh for all vehicle types analysed in 2050 much less than hydrogen transport at ~425532 GWh. We estimate that to power electric transport at least 1515 km2 will be required for solar 1672 km2 for wind and 5 km2 for nuclear. Hydrogen approximately doubles this requirement. Results provide an approximation of the future demands from the transport sector on land and sea area use indicating that a combined electric and hydrogen network will be needed to accommodate a range of socio-economic requirements. While robust assessments of ES and NC impacts are critical in future policies and planning significant reductions in energy demands through a modal shift to (low emission) public transport will be most effective in ensuring a sustainable transport future.
Alkaline Fuel cell Technology - A review
Apr 2021
Publication
The realm of alkaline-based fuel cells has with the arrival of anionic exchange membrane fuel cells (AEMFCs) taken a great step to replace traditional liquid electrolyte alkaline fuel cells (AFCs). The following review summarises progress bottleneck issues and highlights the most recent research trends within the field. The activity of alkaline catalyst materials has greatly advanced however achieving long-term stability remains a challenge. Great AEMFC performances are reported though these are generally obtained through the employment of platinum group metals (PGMs) thus emphasising the importance of R&D related to non-PGM materials. Thorough design strategies must be utilised for all components to avoid a mismatch of electrochemical properties between electrode components. Lastly AEMFC optimisation challenges on the system-level will also have to be assessed as few application-size AEMFCs have been built and tested.
The Technical and Economic Potential of the H2@Scale Concept within the United States
Oct 2020
Publication
The U.S. energy system is evolving as society and technologies change. Renewable electricity generation—especially from wind and solar—is growing rapidly and alternative energy sources are being developed and implemented across the residential commercial transportation and industrial sectors to take advantage of their cost security and health benefits. Systemic changes present numerous challenges to grid resiliency and energy affordability creating a need for synergistic solutions that satisfy multiple applications while yielding system-wide cost and emissions benefits. One such solution is an integrated hydrogen energy system (Figure ES-1). This is the focus of H2@Scale—a U.S. Department of Energy (DOE) initiative led by the Office of Energy Efficiency and Renewable Energy’s Hydrogen and Fuel Technologies Office. H2@Scale brings together stakeholders to advance affordable hydrogen production transport storage and utilization in multiple energy sectors. The H2@Scale concept involves hydrogen as an energy intermediate. Hydrogen can be produced from various conventional and renewable energy sources including as a responsive load on the electric grid. Hydrogen has many current applications and many more potential applications such as energy for transportation—used directly in fuel cell electric vehicles (FCEVs) as a feedstock for synthetic fuels and to upgrade oil and biomass—feedstock for industry (e.g. for ammonia production metals refining and other end uses) heat for industry and buildings and electricity storage. Owing to its flexibility and fungibility a hydrogen intermediate could link energy sources that have surplus availability to markets that require energy or chemical feedstocks benefiting both. This document builds upon a growing body of analyses of hydrogen as an energy intermediate by reporting the results from our initial analysis of the potential impacts of the H2@Scale vision by the mid-21st century for the 48 contiguous U.S. states. Previous estimates have been based on expert elicitation and focused on hydrogen demands. We build upon them first by estimating hydrogen’s serviceable consumption potential for possible hydrogen applications and the technical potential for producing hydrogen from various resources. We define the serviceable consumption potential as the quantity of hydrogen that would be consumed to serve the portion of the market that could be captured without considering economics (i.e. if the price of hydrogen were $0/kg over an extended period); thus it can be considered an upper bound for the size of the market. We define the technical potential as the resource potential constrained by real-world geography and system performance but not by economics. We then compare the cumulative serviceable consumption potential with the technical potential of a number of possible sources. Second we estimate economic potential: the quantity of hydrogen at an equilibrium price at which suppliers are willing to sell and consumers are willing to buy the same quantity of hydrogen. We believe this method provides a deeper understanding than was available in the previous analyses. We develop economic potentials for multiple scenarios across various market and technology-advancement assumptions.
Thoughts on the Prospects of Renewable Hydrogen
Oct 2020
Publication
In the last two years or so there has been increasing interest in hydrogen as an energy source in Australia and around the world. Notably this is not the first time that hydrogen has caught our collective interest. Most recently the 2000s saw a substantial investment in hydrogen research development and demonstration around the world. Prior to that the oil crises of the 1970s also stimulated significant investment in hydrogen and earlier still the literature on hydrogen was not lacking. And yet the hydrogen economy is still an idea only.<br/>So what if anything might be different this time?<br/>This is an important question that we all need to ask and for which the author can only give two potential answers. First our need to make dramatic reductions in greenhouse gas (GHG) emissions has become more pressing since these previous waves of interest. Second renewable energy is considerably more affordable now than it was before and it has consistently outperformed expectations in terms of cost reductions by even its strongest supporters.<br/>While this dramatic and ongoing reduction in the cost of renewables is very promising our need to achieve substantial GHG emission reductions is the crucial challenge. Moreover meeting this challenge needs to be achieved with as little adverse social and economic impact as possible.<br/>When considering what role hydrogen might play we should first think carefully about the massive scale and complexity of our global energy system and the typical prices of the major energy commodities. This provides insights into what opportunities hydrogen may have. Considering a temperate country with a small population like Australia we see that domestic natural gas and transport fuel markets are comparable to and even larger than the electricity market on an energy basis.
Potential and Challenges of Low-carbon Energy Options: Comparative Assessment of Alternative Fuels for the Transport Sector
Dec 2018
Publication
The deployment of low-emission alternative fuels is crucial to decarbonise the transport sector. A number of alternatives like hydrogen or dimethyl ether/methanol synthesised using CO2 as feedstock for fuel production (hereafter refer to “CO2-based fuels”) have been proposed to combat climate change. However the decarbonisation potential of CO2-based fuels is under debate because CO2 is re-emitted to the atmosphere when the fuel is combusted; and the majority of hydrogen still relies on fossil resources which makes its prospects of being a low-carbon fuel dependent on its manufacturing process. First this paper investigates the relative economic and environmental performance of hydrogen (produced from conventional steam methane reforming and produced via electrolysis using renewable energy) and CO2- based fuels (dimethyl ether and methanol) considering the full carbon cycle. The results reveal that hydrogen produced from steam methane reforming is the most economical option and that hydrogen produced via electrolysis using renewables has the best environmental profile. Whereas the idea of CO2-based fuels has recently gained much interest it has for the foreseeable future rather limited practical relevance since there is no favourable combination of cost and environmental performance. This will only change in the long run and requires that CO2 is of non-fossil origin i.e. from biomass combustion or captured from air. Second this paper address unresolved methodological issues in the assessment of CO2-based fuels such as the possible allocation of emissions to the different sectors involved. The outcomes indicate that implementing different allocation approaches substantially influences the carbon footprint of CO2-based fuels. To avoid allocation issues expanding the boundaries including the entire system and is therefore recommended.
Precooling Temperature Relaxation Technology in Hydrogen Refueling for Fuel-Cell Vehicles
Aug 2021
Publication
The dissemination of fuel-cell vehicles requires cost reduction of hydrogen refueling stations. The temperature of the supplied hydrogen has currently been cooled to approximately 40 C. This has led to larger equipment and increased electric power consumption. This study achieves a relaxation of the precooling temperature to the 20 C level while maintaining the refueling time. (1) Adoption of an MC formula that can flexibly change the refueling rate according to the precooling temperature. (2) Measurement of thermal capacity of refueling system parts and re-evaluation. Selection from multiple refueling control maps according to the dispenser design (Mathison et al. 2015). (3) Calculation of the effective thermal capacity and reselection of the map in real time when the line is cooled from refueling of the previous vehicle (Mathison and Handa 2015). (4) Addition of maps in which the minimum assumed pressures are 10 and 15 MPa. The new method is named MC Multi Map
Wind Power to Methanol: Renewable Methanol Production Using Electricity, Electrolysis of Water and CO2 Air Capture
Feb 2020
Publication
A 100 MW stand-alone wind power to methanol process has been evaluated to determine the capital requirement and power to methanol efficiency. Power available for electrolysis determines the amount of hydrogen produced. The stoichiometric amount of CO2– required for the methanol synthesis – is produced using direct air capture. Integration of utilities for CO2 air capture hydrogen production from co-harvested water and methanol synthesis is incorporated and capital costs for all process steps are estimated. Power to methanol efficiency is determined to be around 50%. The cost of methanol is around 300€ ton−1 excluding and 800€ ton−1 including wind turbine capital cost. Excluding 300 M€ investment cost for 100 MW of wind turbines total plant capital cost is around 200 M€. About 45% of the capital cost is reserved for the electrolysers 50% for the CO2 air capture installation and 5% for the methanol synthesis system. The conceptual design and evaluation shows that renewable methanol produced from air captured CO2 water and renewable electricity is becoming a realistic option at reasonable costs of 750–800 € ton−1.
Performance Analysis of a Flexi-Fuel Turbine-Combined Free-Piston Engine Generator
Jul 2019
Publication
The turbine-combined free-piston engine generator (TCFPEG) is a hybrid machine generating both mechanical work from the gas turbine and electricity from the linear electric generator for battery charging. In the present study the system performance of the designed TCFPEG system is predicted using a validated numerical model. A parametric analysis is undertaken based on the influence of the engine load valve timing the number of linear generators adopted and different fuels on the system performance. It is found that when linear electric generators are connected with the free-piston gas turbine the bottom dead centre the peak piston velocity and engine operation frequency are all reduced. Very minimal difference on the in-cylinder pressure and the compressor pressure is observed while the peak pressure in the bounce chamber is reduced. When coupled with a linear electric generator the system efficiency can be improved to nearly 50% by optimising engine load and the number of the linear generators adopted in the TCFPEG system. The system is able to be operated with different fuels as the piston is not limited by a mechanical system; the output power and system efficiency are highest when hydrogen is used as the fuel.
Review on Blended Hydrogen-fuel Internal Combustion Engines: A Case Study for China
Apr 2022
Publication
Under the dual pressure of energy conservation and environmental protection the internal combustion engine industry is facing huge challenges and it is imperative to find new clean energy. Hydrogen energy is expected to replace traditional fossil fuels as an excellent fuel for internal combustion engines because of its clean continuous regeneration and good combustion performance. This review article focuses on the research and development of blended hydrogen-fuel internal combustion engines in China since the beginning of this century. The main achievements gained by Chinese researchers in performing research on the effects of the addition of hydrogen into engines which predominantly include many types of hydrogen-blended engines such as gasoline diesel natural gas and alcohol engines rotary engines are discussed and analyzed in these areas of the engine’s performance and the combustion and emission characteristics etc. The merits and demerits of blended hydrogen-fuel internal combustion engines could be concluded and summarized after discussion. Finally the development trend and direction of exploration on hydrogen-fuel internal combustion engines could also be forecasted for relevant researchers.
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.
Developing New Understanding of Photoelectrochemical Water Splitting Via In-situ Techniques: A Review on Recent Progress
Mar 2014
Publication
Photoelectrochemical (PEC) water splitting is a promising technology for solar hydrogen production to build a sustainable renewable and clean energy economy. Given the complexity of the PEC water splitting processes it is important to note that developing in-situ techniques for studying PEC water splitting presents a formidable challenge. This review is aimed at highlighting advantages and disadvantages of each technique while offering a pathway of potentially combining several techniques to address different aspects of interfacial processes in PEC water splitting. We reviewed recent progress in various techniques and approaches utilized to study PEC water splitting focusing on spectroscopic and scanning-probe methods.
Preparation, Performance and Challenges of Catalyst Layer for Proton Exchange Membrane Fuel Cell
Nov 2021
Publication
In this paper the composition function and structure of the catalyst layer (CL) of a proton exchange membrane fuel cell (PEMFC) are summarized. The hydrogen reduction reaction (HOR) and oxygen reduction reaction (ORR) processes and their mechanisms and the main interfaces of CL (PEM|CL and CL|MPL) are described briefly. The process of mass transfer (hydrogen oxygen and water) proton and electron transfer in MEA are described in detail including their influencing factors. The failure mechanism of CL (Pt particles CL crack CL flooding etc.) and the degradation mechanism of the main components in CL are studied. On the basis of the existing problems a structure optimization strategy for a high‐performance CL is proposed. The commonly used preparation processes of CL are introduced. Based on the classical drying theory the drying process of a wet CL is explained. Finally the research direction and future challenges of CL are pointed out hoping to provide a new perspective for the design and selection of CL materials and preparation equipment.
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.
The Role of Natural Gas and its Infrastructure in Mitigating Greenhouse Gas Emissions, Improving Regional Air Quality, and Renewable Resource Integration
Nov 2017
Publication
The pursuit of future energy systems that can meet electricity demands while supporting the attainment of societal environment goals including mitigating climate change and reducing pollution in the air has led to questions regarding the viability of continued use of natural gas. Natural gas use particularly for electricity generation has increased in recent years due to enhanced resource availability from non-traditional reserves and pressure to reduce greenhouse gasses (GHG) from higher-emitting sources including coal generation. While lower than coal emissions current natural gas power generation strategies primarily utilize combustion with higher emissions of GHG and criteria pollutants than other low-carbon generation options including renewable resources. Furthermore emissions from life cycle stages of natural gas production and distribution can have additional detrimental GHG and air quality (AQ) impacts. On the other hand natural gas power generation can play an important role in supporting renewable resource integration by (1) providing essential load balancing services and (2) supporting the use of gaseous renewable fuels through the existing infrastructure of the natural gas system. Additionally advanced technologies and strategies including fuel cells and combined cooling heating and power (CCHP) systems can facilitate natural gas generation with low emissions and high efficiencies. Thus the role of natural gas generation in the context of GHG mitigation and AQ improvement is complex and multi-faceted requiring consideration of more than simple quantification of total or net emissions. If appropriately constructed and managed natural gas generation could support and advance sustainable and renewable energy. In this paper a review of the literature regarding emissions from natural gas with a focus on power generation is conducted and discussed in the context of GHG and AQ impacts. In addition a pathway forward is proposed for natural gas generation and infrastructure to maximize environmental benefits and support renewable resources in the attainment of emission reductions.
Expectations as a Key to Understanding Actor Strategies in the Field of Fuel Cell and Hydrogen Vehicles
Feb 2012
Publication
Due to its environmental impact the mobility system is increasingly under pressure. The challenges to cope with climate change air quality depleting fossil resources imply the need for a transition of the current mobility system towards a more sustainable one. Expectations and visions have been identified as crucial in the guidance of such transitions and more specifically of actor strategies. Still it remained unclear why the actors involved in transition activities appear to change their strategies frequently and suddenly. The empirical analysis of the expectations and strategies of three actors in the field of hydrogen and fuel cell technology indicates that changing actor strategies can be explained by rather volatile expectations related to different levels. Our case studies of the strategies of two large car manufacturers and the German government demonstrate that the car manufacturers refer strongly to expectations about the future regime while expectations related to the socio-technical landscape level appear to be crucial for the strategy of the German government.
Facile Synthesis of Palladium Phosphide Electrocatalysts and their Activity for the Hydrogen Oxidation, Hydrogen Evolutions, Oxygen Reduction and Formic Acid Oxidation Reactions
Nov 2015
Publication
We demonstrate a new approach for producing highly dispersed supported metal phosphide powders with small particle size improved stability and increased electrocatalytic activity towards some useful reactions. The approach involves a one-step conversion of metal supported on high surface area carbon to the metal phosphide utilising a very simple and scalable synthetic process. We use this approach to produce PdP2 and Pd5P2 particles dispersed on carbon with a particle size of 4.5–5.5 nm by converting a commercially available Pd/C powder. The metal phosphide catalysts were tested for the oxygen reduction hydrogen oxidation and evolution and formic acid oxidation reactions. Compared to the unconverted Pd/C material we find that alloying the P at different levels shifts oxide formation on the Pd to higher potentials leading to greater stability during cycling studies (20% more ECSA retained 5k cycles) and in thermal treatment under air. Hydrogen absorption within the PdP2 and Pd5P2 particles is enhanced. The phosphides compare favourably to the most active catalysts reported to date for formic acid oxidation especially PdP2 and there is a significant decrease in poisoning of the surface compared to Pd alone. The mechanistic changes in the reactions studied are rationalised in terms of increased water activation on the surface phosphorus atoms of the catalyst. One of the catalysts PdP2/C is tested in a fuel cell as anode and cathode catalyst and shows good performance.
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.
Recent Developments in High-Performance Nafion Membranes for Hydrogen Fuel Cells Applications
Aug 2021
Publication
As a promising alternative to petroleum fossil energy polymer electrolyte membrane fuel cell has drawn considerable attention due to its low pollution emission high energy density portability and long operation times. Proton exchange membrane (PEM) like Nafion plays an essential role as the core of fuel cell. A good PEM must have satisfactory performance such as high proton conductivity excellent mechanical strength electrochemical stability and suitable for making membrane electrode assemblies (MEA). However performance degradation and high permeability remain the main shortcomings of Nafion. Therefore the development of a new PEM with better performance in some special conditions is greatly desired. In this review we aim to summarize the latest achievements in improving the Nafion performance that works well under elevated temperature or methanol-fueled systems. The methods described in this article can be divided into some categories utilizing hydrophilic inorganic material metal-organic frameworks nanocomposites and ionic liquids. In addition the mechanism of proton conduction in Nafion membranes is discussed. These composite membranes exhibit some desirable characteristics but the development is still at an early stage. In the future revolutionary approaches are needed to accelerate the application of fuel cells and promote the renewal of energy structure.
Optimal Planning of Hybrid Electric-hydrogen Energy Storage Systems via Multi-objective Particle Swarm Optimization
Jan 2023
Publication
In recent years hydrogen is rapidly developing because it is environmentally friendly and sustainable. In this case hydrogen energy storage systems (HESSs) can be widely used in the distribution network. The application of hybrid electric-hydrogen energy storage systems can solve the adverse effects caused by renewable energy access to the distribution network. In order to ensure the rationality and effectiveness of energy storage systems (ESSs) configuration economic indicators of battery energy storage systems (BESSs) and hydrogen energy storage systems power loss and voltage fluctuation are chosen as the fitness function in this paper. Meanwhile multi-objective particle swarm optimization (MOPSO) is used to solve Pareto non-dominated set of energy storage systems’ optimal configuration scheme in which the technique for order preference by similarity to ideal solution (TOPSIS) based on information entropy weight (IEW) is used select the optimal solution in Pareto non-dominated solution set. Based on the extended IEEE-33 system and IEEE-69 system the rationality of energy storage systems configuration scheme under 20% and 35% renewable energy penetration rate is analyzed. The simulation results show that the power loss can be reduced by 7.9%–22.8% and the voltage fluctuation can be reduced by 40.0%–71% when the renewable energy penetration rate is 20% and 35% respectively in IEEE-33 and 69 nodes systems. Therefore it can be concluded that the locations and capacities of energy storage systems obtained by multi-objective particle swarm optimization can improve the distribution network stability and economy after accessing renewable generation.
No more items...