Applications & Pathways

This paper presents a Linear Joule Engine Generator (LJEG) powered by ammonia and hydrogen co-combustion to tackle decarbonisation in the electrification of transport propulsion systems. A dynamic model of the LJEG which integrates mechanics thermodynamics and electromagnetics sub-models as well as detailed combustion chemistry analysis for emissions is presented. The dynamic model is integrated and validated and the LJEG performance is optimised for improved performance and reduced emissions. At optimal conditions the engine could generate 1.96 kWe at a thermal efficiency of 34.3% and an electrical efficiency of 91%. It is found that the electromagnetic force of the linear alternator and heat addition from the external combustor and engine valve timing have the most significant influences on performance whereas the piston stroke has a lesser impact. The impacts of hydrogen ratio oxygen concentration inlet pressure and equivalence ratio of ammonia-air on nitric oxide (NO) formation and reduction are revealed using a detailed chemical kinetic analysis. Results indicated that rich combustion and elevated pressure are beneficial for NO reduction. The rate of production analysis indicates that the equivalence ratio significantly changes the relative contribution among the critical NO formation and reduction reaction pathways.

This paper presents a wind-methanol-fuel cell system with hydrogen storage. It can manage various energy flow to provide stable wind power supply produce constant methanol and reduce CO2 emissions. Firstly this study establishes the theoretical basis and formulation algorithms. And then computational experiments are developed with MATLAB/Simulink (R2016a MathWorks Natick MA USA). Real data are used to fit the developed models in the study. From the test results the developed system can generate maximum electricity whilst maintaining a stable production of methanol with the aid of a hybrid energy storage system (HESS). A sophisticated control scheme is also developed to coordinate these actions to achieve satisfactory system performance.

Present work investigates the potential of a long-range commercial blended wing body configuration powered by hydrogen combustion engines with future airframe and propulsion technologies. Future technologies include advanced materials load alleviation techniques boundary layer ingestion and ultra-high bypass ratio engines. The hydrogen combustion configuration was compared to the configuration powered by kerosene with respect to geometric properties performance characteristics energy demand equivalent CO2 emissions and Direct Operating Costs. In addition technology sensitivity studies were performed to assess the potential influence of each technology on the configuration. A multi-fidelity sizing methodology using low- and mid-fidelity methods for rapid configuration sizing was created to assess the configuration and perform robust analyses and multi-disciplinary optimizations. To assess potential uncertainties of the fidelity of aerodynamic analysis tools high-fidelity aerodynamic analysis and optimization framework MACHAero was used for additional verification. Comparison of hydrogen and kerosene blended wing body aircraft showed a potential reduction of equivalent CO2 emission by 15% and 81% for blue and green hydrogen compared to the kerosene blended wing body and by 44% and 88% with respect to a conventional B777-300ER aircraft. Advancements in future technologies also significantly affect the geometric layout of aircraft. Boundary layer ingestion and ultra-high bypass ratio engines demonstrated the highest potential for fuel reduction although both technologies conflict with each other. However operating costs of hydrogen aircraft could establish a significant problem if pessimistic and base hydrogen price scenarios are achieved for blue and green hydrogen respectively. Finally configurational problems featured by classical blended wing body aircraft are magnified for the hydrogen case due to the significant volume requirements to store hydrogen fuel.

Several countries have revised their targets in recent years to reach net-zero CO2 emissions across all sectors by 2050 and the transport sector is responsible for a significant share of these emissions. This study compares possible pathways to decarbonise the transport sector through electrification including passenger cars light commercial vehicles and heavy commercial vehicles. To do so we explore 125 scenarios by varying the share of battery and hydrogen-based fuel cell electric vehicles in each of the three categories above independently. We further model the decarbonisation of the industrial hydrogen demand using electrolysers with hydrogen storage. To explore the potential role of electric and hydrogen transport as well as their trade-offs we use GRIMSEL an open-source sector coupling energy system model of Switzerland which includes the residential commercial industrial and transport sectors with four energy carriers namely electricity heat hot water and hydrogen. The total costs are minimised from a social planner perspective. We find that the full electrification of the transport sector could lead on average to a 12% increase in costs by 2050 and 1.3 MtCO2/year which represents a 90% CO2 emissions reduction for the whole sector. Second the transport energy self-sufficiency (i.e. the share of domestic electricity generation in final transport demand) may reach up to 50% for the scenarios with the largest share of battery electric vehicles mainly due to a smaller energy demand than with hydrogen vehicles. Third more than three quarters of the industrial hydrogen production is met by local photovoltaic electricity coupled with battery at minimum costs i.e. green hydrogen. Finally the use of hydrogen as an energy carrier to store electricity over a long period is not cost-optimal.

Especially the electrification of the industry sector is highly complex and challenging mainly due to process-specific requirements. In this context there are several industrial processes where the direct and indirect use of electricity is subject to technical restrictions. In order to achieve the national climate goals the fossil energy consumption remaining after the implementation of efficiency and sufficiency measures as well as direct electrification has to be substituted through hydrogen and synthetic gaseous liquid and solid hydrocarbons. As the main research object the role of synthetic fuels in industrial transformation paths is investigated and analyzed by combining individual greenhouse gas abatement measures within the Sector Model Industry. Sector Model Industry is an energy consumption model that performs discrete deterministic energy and emission dynamic calculations with a time horizon up to 2050 at macroeconomic level. The results indicate that the use of synthetic fuels can be expected with a high level of climate protection. The industrial CO2 target in the model makes it necessary to replace CO2 -intensive fossil with renewable fuels. The model uses a total of 163 TWh of synthetic fuels in the climate protection scenario and thus achieves an 88% decrease in CO2 emissions in 2050 compared to 1990. This means that the GHG abatement achieved in industry is within the range of the targeted CO2 mitigation of the overall system in Germany of between 80 and 95% in 2050 compared to 1990. Due to technical restrictions the model mainly uses synthetic methane instead of hydrogen (134 TWh). The results show that despite high costs synthetic fuels are crucial for defossilization as a fall back option in the industrial scenario considering high climate ambition. The scenario does not include hydrogen technologies for heat supply. Accordingly the climate protection scenario uses hydrogen only in the steel industry for the direct reduction of iron (21 TWh). 8 TWh of synthetic oil substitute the same amount of fossil oil in the climate protection scenario. A further analysis conducted on the basis of the model results shows that transformation in the energy system and the use of smart ideas concepts and technologies are a basic prerequisite for enabling the holistic defossilisation of industry. The findings in the research can contribute to the cost-efficient use of synthetic fuels in industry and thus serve as a basis for political decision making. Moreover the results may have a practical relevance not only serving as a solid comparison base for the outcome of other studies but also as input data for further simulation of energy system transformation paths.

Global supply chains must be decarbonised as part of meeting climate targets set by the United Nations and world leaders. Rail networks are vital infrastructure in passenger and freight transport however have not received the same push for decarbonisation as road transport. In this investigation we used real world data from locomotives operating on seven rail corridors to identify optimal battery capacity and hydrogen fuel cell (HFC) power in hybrid systems. We found that the required battery capacity is dependent on both the available regenerative braking energy and on the capacity required to buffer surpluses and deficits from the HFC. The optimal system for each corridor was identified however it was found that one 3.6 MWh battery and 860 kW HFC system could service six of the seven corridors. The optimal systems presented in this work suggest an average of around 5 h of battery storage for the HFC power which is larger than the 2 h previously reported in literature. This may indicate a gap between purely theoretical works that use only route topography and speed and those that employ real world locomotive data.

To maximize the utilization of renewable energy (RE) as much as possible in cold areas while reducing traditional energy use and carbon dioxide emissions a three-layer configuration optimization and scheduling model considering a multi-park integrated energy system (MPIES) a shared energy storage power station (SESPS) and a hydrogen refueling station (HRS) cooperation based on the Wasserstein generative adversarial networks the simultaneous backward reduction technique and the Quantity-Contour (WGAN-SBR_QC) method is proposed. Firstly the WGAN-SBR_QC method is used to generate typical scenarios of RE output. Secondly a three-layer configuration and schedule optimization model is constructed using MPIES SESPS and HRS. Finally the model’s validity is investigated by selecting a multi-park in Eastern Mongolia. The results show that: (1) the typical scenario of RE output improved the overall robustness of the system. (2) The profits of the MPIES and HRS increased by 1.84% and 52.68% respectively and the SESPS profit increased considerably. (3) The proposed approach increased RE utilization to 99.47% while reducing carbon emissions by 32.67%. Thus this model is a reference for complex energy system configuration and scheduling as well as a means of encouraging RE use.

Hydrogen eliminates carbon emissions from compression ignition (CI) engines while noble gases eliminate nitrogen oxide (NOx) emissions by replacing nitrogen. Noble gases can increase the in-cylinder temperature during the compression stroke due to their high specific heat ratio. This paper aims to find the optimum parameters for hydrogen combustion in an argon–oxygen atmosphere and to study hydrogen combustion in all noble gases providing hydrogen combustion data with suitable engine parameters to predict hydrogen ignitability under different conditions. Simulations are performed with Converge CFD software based on the Yanmar NF19SK direct injection CI (DICI) engine parameters. The results are validated with the experimental results of hydrogen combustion in an argon–oxygen atmosphere with a rapid compression expansion machine (RCEM) and modifications of the hydrogen injection timing and initial temperature are proposed. Hydrogen ignition in an argon atmosphere is dependent on a minimum initial temperature of 340 K but the combustion is slightly unstable. Helium and neon are found to be suitable for hydrogen combustion in low compression ratio (CR) engines. However krypton and xenon require temperature modification and a high CR for stable ignition. Detailed parameter recommendations are needed to improve hydrogen ignitability in conventional diesel engines with the least engine modification.

The state of environmental pollution brought about as a result of the modern civilization has been monitored in the interests of the environment and human health since the seventies of the last century. Ensuring the energy security is one of the most basic existential requirements for a functional civilized society. The growing civilizational needs caused by broadly understood development generate demand for the production of all kinds of goods in all sectors of the economy as well as world-wide information transfer. The current energy demand is mostly covered using fossil fuels such as coal oil and natural gas. Some of the energy demand is covered by the energy generated in nuclear reactions and a small part of it comes from renewable energy sources. Energy derived from fossil fuels is inevitably associated with fuel oxidation processes. These processes in addition to generating heat are responsible for the emission of harmful compounds to the atmosphere: carbon monoxide carbon dioxide nitrogen oxides hydrocarbons and particulate matter. These pollutants pose a serious threat to the people as well as the environment in which they live. Due to the large share of fossil fuel energy generation in the process of combustion it becomes necessary to seek other means of obtaining the so-called "clean energy". Fuel cells may have a very high potential in this respect. Their development has enabled attempts to use them in all modes of transport. An important factor in the development of fuel cells is their relatively high efficiency and the coinciding strictening of the emission norms from internal combustion engines used to power maritime transport. Therefore the aim of this article has been to assess the potential of fuel cells as a main source of propulsion power source. A review of the designs of fuel cell systems and their use was performed. The article summarizes the assessment of the potential role of fuel cells as a power source of maritime transport.

With a relatively high energy density hydrogen is attracting increasing attention in research commercial and political spheres specifically as a fuel for residential heating which is proving to be a difficult sector to decarbonise in some circumstances. Hydrogen production is dependent on the power system so any scale use of hydrogen for residential heating will impact various aspects of the power system including electricity prices and renewable generation curtailment (i.e. wind solar). Using a linearised optimal power flow model and the power infrastructure on the island of Ireland this paper examines least cost optimal investment in electrolysers in the presence of Ireland's 70% renewable electricity target by 2030. The introduction of electrolysers in the power system leads to an increase in emissions from power generation which is inconsistent with some definitions of green hydrogen. Electricity prices are marginally higher with electrolysers whereas the optimal location of electrolysers is driven by a combination of residential heating demand and potential surplus power supplies at electricity nodes.