Publications

NREL has been developing compliance verification tools for allowable hydrogen levels prescribed by the Global Technical Regulation Number 13 (GTR-13) for hydrogen fuel cell electric vehicles (FCEVs). As per GTR-13 FCEV exhaust is to remain below 4 vol% H2 over a 3-second moving average and shall not at any time exceed 8 vol% H2 and that this requirement is to be verified with an analyzer that has a response time of less than 300 ms. To be enforceable a means to verify regulatory requirements must exist. In response to this need NREL developed a prototype analyzer that meets the GTR metrological requirements for FCEV exhaust analysis. The analyzer was tested on a commercial fuel cell electric vehicle (FCEV) under simulated driving conditions using a chassis dynamometer at the Emissions Research and Measurement Section of Environment and Climate Change Canada and FCEV exhaust was successfully profiled. Although the prototype FCEV Exhaust Analyzer met the metrological requirements of GTR-13 the stability of the hydrogen sensor was adversely impacted by condensed water in the sample gas. FCEV exhaust is at an elevated temperature and nearly saturated with water vapor. Furthermore condensed water is present in the form of droplets. Condensed water in the sample gas collected from FCEV exhaust can accumulate on the hydrogen sensing element which would not only block access of hydrogen to the sensing element but can also permanently damage the sensor electronics. In the past year the design of the gas sampling system was modified to mitigate against the transport of liquid water to the sensing element. Laboratory testing confirmed the effectiveness of the modified sampling system water removal strategy while maintaining the measurement range and response time required by GTR-13. Testing of the upgraded analyzer design on an FCEV operating on a chassis dynamometer is scheduled for the summer of 2021.

The conversion to renewable energy can be achieved when cities and communities start to depend on sustainable resources capable of providing for the basic needs of the community along with a reduction in the daily problems and issues that people face. These issues such as poverty hunger sanitation and economic difficulties are highlighted in the Sustainable Development Goals (SDGs) which aim to limit and eradicate these problems along with other environmental obstacles including climate change and Greenhouse Gases (GHGs). These SDGs containing 17 goals target each sector and provide propositions to solve such devastating problems. Hydrogen contributes to the targets of these sustainable developments since through its implementation in different industries the levels of GHG will drop and thus contribute to the climate change which Earth is facing. Further through the usage of such resources many job opportunities will also be developed thus enhancing the economy and lifting the status of society. This paper classifies the four different types of hydrogen and outlines the differences between them. The paper then emphasizes the importance of green hydrogen use within the shipping industry transportation and infrastructure along with economic and social development through job opportunities. Furthermore this paper provides case studies tackling green hydrogen status in the United Kingdom United States of America and European Union as well as Africa United Arab of Emirates and Asia. Finally challenges and recommendations concerning the green hydrogen industry are addressed. This paper aims to relate the use of green hydrogen to the direct and indirect goals of SDG.

The coupling of renewable energy and hydrogen technologies represents in the mid-term a very interesting way to match the tasks of increasing the reliable exploitation of wind and sea wave energy and introducing clean technologies in the transportation sector. This paper presents two different feasibility studies: the first proposes two plants based on wind and sea wave resource for the production storage and distribution of hydrogen for public transportation facilities in the West Sicily; the second applies the same approach to Pantelleria (a smaller island) including also some indications about solar resource. In both cases all buses will be equipped with fuel-cells. A first economic analysis is presented together with the assessment of the avoidable greenhouse gas emissions during the operation phase. The scenarios addressed permit to correlate the demand of urban transport to renewable resources present in the territories and to the modern technologies available for the production of hydrogen from renewable energies. The study focuses on the possibility of tapping the renewable energy potential (wind and sea wave) for the hydrogen production by electrolysis. The use of hydrogen would significantly reduce emissions of particulate matter and greenhouse gases in urban districts under analysis. The procedures applied in the present article as well as the main equations used are the result of previous applications made in different technical fields that show a good replicability.

As the demand for alternative fuels to solve environmental problems increases worldwide due to the greenhouse gas problem this study predicted the demand for liquid hydrogen fuel in aviation to achieve ‘zero‐emission flight’. The liquid hydrogen fuel models of an aircraft and all aviation sectors were produced based on the prediction of aviation fleet growth through the classification of currently operated aircraft. Using these models the required amount of liquid hydrogen fuel and the total cost of liquid hydrogen were also calculated when various environmental regulations were satisfied. As a result it was found to be necessary to convert approximately 66% to 100% of all aircraft from existing aircraft to liquid hydrogen aircraft in 2050 according to regulations. The annual liquid hydrogen cost was 4.7–5.2 times higher in the beginning due to the high production cost but after 2030 it will be maintained at almost the same price and it was found that the cost was rather low compared to jet fuel.

The European Union’s target to reach greenhouse gas neutrality by 2050 calls for a sharp decrease in the consumption of natural gas. This study assesses impacts of greenhouse gas neutrality on the gas system taking France and Germany as two case studies which illustrate a wide range of potential developments within the European Union. Based on a review of French and German GHG-neutral scenarios it explores impacts on gas infrastructure and estimates the changes in end-user methane price considering a business-as-usual and an optimised infrastructure pathway. Our results show that gas supply and demand radically change by mid-century across various scenarios. Moreover the analysis suggests that deep transformations of the gas infrastructure are required and that according to the existing pricing mechanisms the end-user price of methane will increase driven by the switch to low-carbon gases and intensified by infrastructure costs.

Hydrogen has emerged as a new energy vector beyond its usual role as an industrial feedstock primarily for the production of ammonia methanol and petroleum refining. In addition to environmental sustainability issues energy-scarce developed countries such as Japan and Korea are also facing an energy security issue and hydrogen or hydrogen carriers such as ammonia and methylcyclohexane seem to be options to address these long-term energy availability issues. China has been eagerly developing renewable energy and hydrogen infrastructure to meet their sustainability goals and the growing energy demand. In this review we focus on hydrogen electrification through proton-exchange membrane fuel cells (PEMFCs) which are widely believed to be commercially suitable for automotive applications particularly for vehicles requiring minimal hydrogen infrastructure support such as fleets of taxies buses and logistic vehicles. This review covers all the key components of PEMFCs thermal and water management and related characterization techniques. A special consideration of PEMFCs in automotive applications is the highlight of this work leading to the infrastructure development for hydrogen generation storage and transportation. Furthermore national strategies toward the use of hydrogen are reviewed thereby setting the rationale for the hydrogen economy.

As the backbone of global trade international maritime transport connects the world and facilitates economic growth and development especially in developing countries. However producing around three percent of global greenhouse gas (GHG) emissions and emitting around 15 percent of some of the world’s major air pollutants shipping is a major contributor to climate change and air pollution. To mitigate its negative environmental impact shipping needs to abandon fossil-based bunker fuels and turn to zero-carbon alternatives. This report the “Summary for Policymakers and Industry” summarizes recent World Bank research on decarbonizing the maritime sector. The analysis identifies green ammonia and hydrogen as the most promising zero-carbon bunker fuels within the maritime industry at present. These fuels strike the most advantageous balance of favorable features relating to their lifecycle GHG emissions broader environmental factors scalability economics and technical and safety implications. The analysis also identifies that LNG will likely only play a limited role in shipping’s energy transition due to concerns over methane slip and stranded assets. Crucially the research reveals that decarbonizing maritime transport offers unique business and development opportunities for developing countries. Developing countries with large renewable energy resources could take advantage of the new and emerging future zero-carbon bunker fuel market estimated at over $1 trillion to establish new export markets while also modernizing their own domestic energy and industrial infrastructure. However strategic policy interventions are needed to hasten the sector’s energy transition.

Hydrogen (H2) is currently used mainly in the chemical industry for the production of ammonia and methanol. Nevertheless in the near future hydrogen is expected to become a significant fuel that will largely contribute to the quality of atmospheric air. Hydrogen as a chemical element (H) is the most widespread one on the earth and as molecular dihydrogen (H2) can be obtained from a number of sources both renewable and nonrenewable by various processes. Hydrogen global production has so far been dominated by fossil fuels with the most significant contemporary technologies being the steam reforming of hydrocarbons (e.g. natural gas). Pure hydrogen is also produced by electrolysis of water an energy demanding process. This work reviews the current technologies used for hydrogen (H2) production from both fossil and renewable biomass resources including reforming (steam partial oxidation autothermal plasma and aqueous phase) and pyrolysis. In addition other methods for generating hydrogen (e.g. electrolysis of water) and purification methods such as desulfurization and water-gas shift reactions are discussed.

Hydrogen is a key cornerstone of the green transformation of the global economy and a major lever to diversify energy supplies and accelerate the clean energy transition. Hydrogen will be essential to replace natural gas coal and oil in hard-to-decarbonise sectors in industry mobility and energy. Hydrogen Valleys will become an important cornerstone in producing importing transporting and using clean hydrogen in Europe.

Hydrogen is one of the main alternative fuels with the greatest potential to replace fossil fuels due to its renewable and environmentally friendly nature. Due to this the present investigation aims to evaluate the combustion characteristics performance parameters emissions and variations in the characteristics of the lubricating oil. The investigation was conducted in a spark-ignition engine fueled by gasoline and hydrogen gas. Four engine load conditions (25% 50% 75% and 100%) and three hydrogen gas mass concentration conditions (3% 6% and 9%) were defined for the study. The investigation results allowed to demonstrate that the injection of hydrogen gas in the gasoline engine causes an increase of 3.2% and 4.0% in the maximum values of combustion pressure and heat release rates. Additionally hydrogen causes a 2.9% increase in engine BTE. Hydrogen's more efficient combustion process allowed for reducing CO HC and smoke opacity emissions. However hydrogen gas causes an additional increase of 14.5% and 30.4% in reducing the kinematic viscosity and the total base number of the lubricating oil. In addition there was evidence of an increase in the concentration of wear debris such as Fe and Cu which implies higher rates of wear in the engine's internal components.