Greece

An engineering tool is presented to predict steady state two-phase choked flow through a discharge line with variable cross section with account of friction and without wall heat transfer. The tool is able to predict the distribution of all relevant physical quantities along the discharge line. Choked flow is calculated using the possible-impossible flow algorithm implemented in a way to account for possible density discontinuities along the line. Physical propertie Read More

In the present work CFD simulations of a hydrogen deflagration experiment are performed. The experiment carried out by KIT was conducted in a 1 m3 enclosure with a square vent of 0.5 m2 located in the center of one of its walls. The enclosure was filled with homogeneous hydrogen-air mixture of 18% v/v before ignition at its back-wall. As the flame propagates away from the ignition point unburned mixture is forced out through the vent. This mixtur Read More

The rapid development of science technology and engineering in the 21st century has offered a remarkable rise in our living standards. However at the same time serious environmental issues have emerged such as acid rain and the greenhouse effect which are associated with the ever-increasing need for energy consumption 85% of which comes from fossil fuels combustion. From this combustion process except for energy the main greenhouse gases-carb Read More

Atomic hydrogen produced by corrosion of a low-carbon steel in NaCl – Water solution may markedly affect its certain tensile mechanical and magnetic properties in a complex and peculiar manner. This influence was investigated by employing the intrinsic micromagnetic emission (ME)-response as well as tensile mechanical response of this ferromagnetic material and also by introduction a relevant measurement parameter of specific micromagneti Read More

This paper explores the alternative roles hydrogen can play in the future European Union (EU) energy system within the transition towards a carbon-neutral EU economy by 2050 following the latest policy developments after the COP21 agreement in Paris in 2015. Hydrogen could serve as an end-use fuel a feedstock to produce carbon-neutral hydrocarbons and a carrier of chemical storage of electricity. We apply a model-based energy system analys Read More

Hydrogen cars are expected to play an important role in a decarbonised clean-transport future. Safety issues arise though in tunnels due to the possibility of accidental release and accumulation of hydrogen. This Computational Fluid Dynamics (CFD) study focuses on the effect of tunnel inclination and ventilation on hydrogen dispersion. A horseshoe shaped tunnel of 200 m length is considered in all seventeen cases examined. In most cases hydrogen is rel Read More

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 t Read More

During the past few years hydrogen use has come to be considered as an alternative energy carrier in a future decarbonized world. Many developed nations are undergoing a shift towards low-carbon energy sources driven by the excessive reliance on fossil fuels and the detrimental effects of climate change. This study aims to investigate the potential for hydrogen deployment in the Greek energy market during the next few decades. In this context green hy Read More

Extensive decarbonisation efforts result in major changes in energy demand for the extractive industry. In 2021 the extraction and primary processing of metals and minerals accounted for 4.5 Gt of CO2 eq. per year. The aluminium industry was responsible for 1.1 Gt CO2 eq. direct and indirect emissions. To reach the European milestone of zero emissions by 2050 a reduction of 3% annually is essential. To this end the industry needs to take a turn towa Read More

In April 2018 the International Maritime Organisation adopted an ambitious plan to contribute to the global efforts to reduce the Greenhouse Gas emissions as set by the Paris Agreement by targeting a 50% reduction in shipping’s Green House Gas emissions by 2050 benchmarked to 2008 levels. To meet these challenging goals the maritime industry must introduce environmentally friendly fuels with negligible or low SOX NOX and CO2 emissions. Ammoni Read More