Increasing production rates of the biomethane lead to increased generation of waste biogases. These gases should be utilized on-site to avoid pollutant emissions to the atmosphere. This study presents a flexible swirl burner (~100 kW) with an adiabatic chamber capable of burning unstable composition waste biogases. The main combustion parameters and chemiluminescence emission spectrums were examined by burning waste biogases containing from 5 to 30 vol% of CH₄ in CO₂ under air, O₂-enriched atmosphere, or with the addition of hydrogen. The tested burner ensured stable combustion of waste biogases with CH₄ content not less than 20 vol%. The addition of up to 5 vol% of H₂ expanded flammability limits, and stable combustion of the mixtures with CH₄ content of 15 vol% was achieved. The burner flexibility to work under O₂-enriched air conditions showed more promising results, and the flammability limit was expanded up to 5 vol% of CH₄ in CO₂. However, the combustion under O₂-enriched conditions led to increased NOx emissions (up to 1100 ppm). Besides, based on chemiluminescence emission spectrums, a linear correlation between the spectral intensity ratio of OH* and CH* (I_OH*/I_CH*) and CH₄ content in CO₂ was presented, which predicts blow-off limits burning waste biogases under different H₂ or O₂ enrichments.

In order to implement timely sustainability solutions, road transportation is gradually transitioning to electric power. However, the maritime sector faces challenges in finding ways to shift towards more sustainable fuel. From the perspective of long-distance shipping, electric transport is economically impractical. Therefore, alternative solutions or proposals contributing to the global reduction of pollutant gas emissions in maritime transport are vitally important. This investigation aims to find solutions that enhance the ecological efficiency of intercontinental cargo ships. In this study, an assessment of a magnesium hydride coating was conducted as it is a prospective coating capable of reducing hydrodynamic resistance to save fuel. Due to MgH₂’s ability to release hydrogen at higher temperatures or during a reaction with water, it is expected that this could contribute to an enhancement of the Leidenfrost effect, maintaining a vapor layer on the surface. Samples prepared in situ via reactive magnetron sputtering were submitted to thermal analysis for dehydrogenation range evaluation and the experimental rig for critical (Leidenfrost) temperature identification. In conclusion, thermogravimetric (TG) analysis indicated that the volatile content, primarily hydrogen, in the sample reached approximately 13% by mass. The TG curve exhibited variations in MgH₂ mass, with the most significant mass loss occurring at 300 °C. After conducting critical temperature experiments, the potential of MgO coating was observed to be greater than anticipated when compared to the main material, MgH₂.

European Union (EU) energy markets are changing rapidly. After the recent turmoil, a new wave of EU legislation is once again reshaping the way energy should be used in the EU, emphasizing not only the increasing importance of using renewable and local energy sources but also highlighting the importance of energy efficiency and decarbonization of high to abate sectors (including aviation and marine fuels). Heating and cooling account for about half of the total gross final energy consumption in the EU. This article explores the novel concept of using waste heat from the flexible Fischer–Tropsch (FT) process (FLEXCHX) in the existing district heating network, resulting in tri-generation: FT C5+ liquids, heat, and electricity. FLEXCHX provides operation flexibility and combines advanced biomass gasification, catalytic liquefaction, electrolysis, and waste heat recovery, allowing use of biomass residues in a more sustainable way. Our results, based on the Kaunas district heating (DH) system, show that this process could be integrated into the existing district heating network in Northern Europe and successfully compete with existing heat-only boilers and CHPs using biomass or municipal waste, resulting in more efficient use of biomass and savings accumulated up to EUR 200 million over the study period in the analysis (2020–2050), supplying up to 30% of the heat in the Kaunas DH system. Enriching the FT process with hydrogen (using electrolysis) could result in additional FLEXCHX utilization benefits by creating demand for cheap excess electricity that might otherwise be curtailed.