@misc{11808, abstract = {{The application of hydrogen for energy storage and as a vehicle fuel necessitates efficient and effective storage technologies. In addition to traditional cryogenic and high-pressure tanks, an alternative approach involves utilizing porous materials such as activated carbons within the storage tank. The adsorption behaviour of hydrogen in porous structures is described using the Dubinin-Astakhov isotherm. To model the flow of hydrogen within the tank, we rely on the equations of mass conservation, the Navier-Stokes equations, and the equation of energy conservation, which are implemented in a computational fluid dynamics code and additional terms account for the amount of hydrogen involved in sorption and the corresponding heat release. While physical models are valuable, data-driven models often offer computational advantages. Based on the data from the physical adsorption model, a data-driven model is derived using various machine learning techniques. This model is then incorporated as source terms in the governing conservation equations, resulting in a novel hybrid formulation which is computationally more efficient. Consequently, a new method is presented to compute the temperature and concentration distribution during the charging and discharging of hydrogen tanks and identifying any limiting phenomena more easily.}}, author = {{Klepp, Georg Heinrich}}, booktitle = {{Energy : the international journal ; technologies, resources, reserves, demands, impact, conservation, management, policy}}, issn = {{1873-6785}}, keywords = {{Hydrogen storage, Adsorption, Activated carbon, Machine learning, Simulation, Computational fluid dynamics}}, publisher = {{Elsevier BV}}, title = {{{Modelling activated carbon hydrogen storage tanks using machine learning models}}}, doi = {{10.1016/j.energy.2024.132318}}, volume = {{306}}, year = {{2024}}, } @misc{10784, abstract = {{Replacing carbon-based fuels with hydrogen will not sustainably prevent an ice cube from melting, as CO2 is just one of the (many) causes of human-caused climate change. From an energetic and climatic point of view, it does not matter whether the heat input into the atmosphere occurs through the combustion of fossil carbon or through the combustion of hydrogen (which is difficult to produce): The desired decarbonization alone cannot slow the speed of climate change in our time. Whether global primary energy consumption is based on carbon or hydrogen remains irrelevant to the lifetime of the heat-storing CO2 molecules in atmosphere. Several literature sources on the lifetime of CO2 in the atmosphere vary between a few decades and 1000 years. It is possible that the differences in lifetime are due to the fact that different system boundaries are taken into account. The start of slowing climate change the day after CO2 is no longer released into the atmosphere will certainly only have noticeable consequences several generations later. From today's perspective, the hydrogen-based energy economy cannot be an equivalent replacement for a carbon-based energy economy, but rather only an intermediate step on the way to greater energy efficiency. Energy efficiency means that the ratio between the effort for “energy production” (actually energy conversion) and the benefit as “energy use” (proportion of energy that can be converted into work) must decrease significantly. How? For example, by developing more energy-efficient processes and machines, improving heat storage, using CO2-free renewable energies and using waste heat as much as possible. Sustainability is nothing more than common sense and concerning the use of energy it means daring to be more energetically truthful through greater energy efficiency. }}, author = {{Sietz, Manfred}}, keywords = {{Grüner Wasserstoff, Decarbonisierung, Klimawandel, Meeresspiegelerhöhung, Nachhaltigkeit, green hydrogen, decarbonization, climate change, sea level rise, sustainability}}, pages = {{8}}, publisher = {{Technische Hochschule Ostwestfalen-Lippe}}, title = {{{Von grünem Wasserstoff und farblosem CO2}}}, year = {{2023}}, } @misc{12787, abstract = {{Vapor phase hydrogen peroxide (H2O2) can be utilized to inactivate murine norovirus (MNV), a surrogate of human norovirus, on surface areas. However, vapor phase H2O2 inactivation of virus on fruits and vegetables has not been characterized. In this study, MNV was used to determine whether vaporized H2O2 inactivates virus on surfaces of various fruits and vegetables (apples, blueberries, cucumbers, and strawberries). The effect of vapor phase H2O2 decontamination was investigated with two application systems. Plaque assays were performed after virus recovery from untreated and treated fresh produce to compare the quantity of infective MNV. The Mann-Whitney U test was applied to the test results to evaluate the virus titer reductions of treated food samples, with significance set at P <= 0.05. The infective MNV populations were significantly reduced on smooth surfaces by 4.3 log PFU (apples, P < 0.00001) and 4 log PFU or below the detection limit (blueberries, P = 0.0074) by treatment with vapor phase H2O2 (60 min, maximum of 214 ppm of H2O2). Similar treatments of artificially contaminated cucumbers resulted in a virus titer reduction of 1.9 log PFU. Treatment of inoculated strawberries resulted in 0.1and 2.8-log reductions of MNV. However, MNV reduction rates on cucumbers (P = 0.3809) and strawberries (P = 0,7414) were not significant. Triangle tests and color measurements of untreated and treated apples, cucumbers, blueberries, and strawberries revealed no differences in color and consistency after H2O2 treatment. No increase of the H2O2 concentration in treated fruits and vegetables compared with untreated produce was observed. This study reveals for the first time the conditions under which vapor phase H2O2 inactivates MNV on selected fresh fruit and vegetable surfaces.}}, author = {{Becker, Barbara and Dabisch-Ruthe, Mareike and Pfannebecker, Jens}}, booktitle = {{ Journal of food protection }}, issn = {{1944-9097}}, keywords = {{Fruits, Inactivation, Murine norovirus, Vapor phase hydrogen peroxide, Vegetables}}, number = {{1}}, pages = {{45--51}}, publisher = {{IAFP}}, title = {{{Inactivation of Murine Norovirus on Fruit and Vegetable Surfaces by Vapor Phase Hydrogen Peroxide}}}, doi = {{10.4315/0362-028X.JFP-19-238}}, volume = {{83}}, year = {{2020}}, } @article{1721, abstract = {{In this contribution, the effect of the presence of a presumed inert gas like N2 in the feed gas on the biological methanation of hydrogen and carbon dioxide with Methanothermobacter marburgensis was investigated. N2 can be found as a component besides CO2 in possible feed gases like mine gas, weak gas, or steel mill gas. To determine whether there is an effect on the biological methanation of CO2 and H2 from renewable sources or not, the process was investigated using feed gases containing CO2, H2, and N2 in different ratios, depending on the CO2 content. A possible effect can be a lowered conversion rate of CO2 and H2 to CH4. Feed gases containing up to 47N2 were investigated. The conversion of hydrogen and carbon dioxide was possible with a conversion rate of up to 91 but was limited by the amount of H2 when feeding a stoichiometric ratio of 4:1 and not by adding N2 to the feed gas.}}, author = {{Hoffarth, Marc Philippe and Broeker, Timo and Schneider, Jan}}, issn = {{2311-5637}}, journal = {{Fermentation}}, keywords = {{biological methanation, CSTR, Methanothermobacter marburgensis, methane, carbon dioxide, dinitrogen, hydrogen, power-to-gas}}, number = {{3}}, publisher = {{MDPI }}, title = {{{Effect of N2 on Biological Methanation in a Continuous Stirred-Tank Reactor with Methanothermobacter marburgensis}}}, doi = {{10.3390/fermentation5030056}}, volume = {{5}}, year = {{2019}}, }