Czech Republic

Hydrogen energy is essential in the transition to sustainable transportation planning providing a clean and efficient alternative to traditional fossil fuels. As a versatile energy carrier hydrogen facilitates the decarbonization of diverse transportation modes including passenger vehicles heavy-duty trucks trains and maritime vessels. To justify and clarify the role of hydrogen energy in sustainable transportation planning this study conducts a comprehensive techno-economic and environmental assessment of hydrogen production in the USA Europe and China. Utilizing the Shlaer–Mellor method for policy modeling the analysis highlights regional differences and offers actionable insights to inform strategic decisions and policy frameworks for advancing hydrogen adoption. Hydrogen production potential was assessed from solar and biomass resources with results showing that solar-based hydrogen production is significantly more efficient producing 704 tons/yr/km2 compared to 5.7 tons/yr/km2 from biomass. A Monte Carlo simulation was conducted to project emissions and market share for hydrogen and gasoline vehicles from 2024 to 2050. The results indicate that hydrogen vehicles could achieve near-zero emissions and capture approximately 30% of the market by 2050 while gasoline vehicles will decline to a 60% market share with higher emissions. Furthermore hydrogen production using solar energy in the USA yields a per capita output of 330513 kg/yr compared to 6079 kg/yr from biomass. The study concludes that hydrogen particularly from renewable sources holds significant potential for reducing greenhouse gas emissions with policy frameworks in the USA Europe and China focused on addressing energy dependence air pollution and technological development in the transportation sector.

In the ongoing effort to reduce carbon emissions on a worldwide scale green hydrogen which is generated through environmentally responsible processes has emerged as a significant driving force. As the demand for clean energy continues to rise it is becoming increasingly important to have a solid understanding of the technological and economic elements of modern techniques of producing green hydrogen. In the context of green hydrogen generation understanding green hydrogen production's techno-economic features is necessary to reduce carbon emissions and transition to a low-carbon economy. associated with breakthroughs in technology the present study examines the most fascinating and relevant aspects of techno-economic analysis. Despite challenges green hydrogen can help the world move to a cleaner more sustainable energy future with solid analytical frameworks and legislation.

Hydrogen blending offers significant potential for decarbonizing natural gas-based thermal processes particularly in the steel and cement sectors. Due to its distinct combustion properties compared to natural gas – such as lower minimum air requirements and altered flame speeds – the hydrogen fraction of the fuel must be monitored for combustion control. In this study we present an ultrasonic time-of-flight measurement system for hydrogen concentrations of 0–40% in natural gas. The system is verified with test gas mixtures at laboratory scale and validated in a technical-scale setup using a real blower burner (< 60 kW). We evaluate uncertainty of the hydrogen fraction measurement and analyze the influence of varying natural gas compositions. We show that standard uncertainties below 4% can be achieved without knowledge of the specific natural gas composition. Our results provide insights for measurement system design and support the safe application of hydrogen in thermal systems for industrial processes.

From an environmental standpoint carbon-free energy carriers such as ammonia and hydrogen are essential for future energy systems. However their hightemperature chemical behavior remains insufficiently understood posing challenges for the development and optimization of advanced combustion technologies. Ammonia in particular is globally available and cost-effective especially for energy-intensive industries. The addition of ammonia or hydrogen to methane significantly reduces the accuracy of existing predictive models. Therefore validated and detailed data are urgently needed to enable reliable design and performance predictions. This review highlights the compatibility of ammonia with existing combustion infrastructure facilitating a smoother transition to more sustainable heating methods without the need for entirely new systems. Applications in high-temperature heating processes such as metal processing ceramics and glass production and power generation are of particular interest. This review focuses on the systematic assessment of alternative fuel mixtures comprising ammonia and hydrogen as well as natural gas with particular consideration of existing safety-related parameters and combustion characteristics. Fundamental quantities such as the laminar burning velocity are discussed in the context of their relevance for fuel mixtures and their scalability toward turbulent flame propagation which is of critical importance for industrial burner and reactor design. The influence of fuel composition on ignition limits is examined as these are essential parameters for safety margin definitions and operational boundary conditions. Furthermore flame stability in mixed-fuel systems is addressed to evaluate the practical feasibility and robustness of combustion under varying process conditions. A detailed overview of current diagnostic and analysis methods follows encompassing both pollutant measurement techniques and the detection of key radical species. These diagnostics form the experimental basis for reaction kinetics modeling and mechanism validation. Given the importance of emission formation in combustion systems a dedicated subsection summarizes major emission trends even though a comprehensive treatment would exceed the scope of this review. Thermal radiation effects which are highly relevant for heat transfer and system efficiency in large-scale applications are then reviewed. In parallel current developments in numerical simulation approaches for industrial-scale combustion systems are presented including aspects of model accuracy boundary conditions and computational efficiency. The review also incorporates insights from materials engineering particularly regarding high-temperature material performance corrosion resistance and compatibility with combustion products. Based on these interdisciplinary findings operational strategies for high-temperature furnaces are outlined and selected industrial reference systems are briefly presented. This integrated approach aims to support the design optimization and safe operation of next-generation combustion technologies utilizing carbon-free or low-carbon fuels.