Laser-Stimulated Desorption of Hydrogen in Palladium for Dynamic Hydrogen Sorption Microanalysis

The reaction conditions in industrial scale chemical reactors can differ markedly from the ones in a small laboratory scale reactor. The differences are both conceptual and practical, and can at best be analysed by studying a full reactor, which requires an analytical method capable of quantifying the distribution of reactants and products in a running reactor. For this, we introduce non-destructive operando neutron imaging in combination with modelling. As a representative reaction, we studied the hydrogenation of carbon dioxide to methane selected due to the large neutron cross-section of hydrogen and hydrogen-containing species. The integration of the measurement setup/reactor into the neutron beamline enables the temporally resolved measurement of the distribution of adsorbed water on the catalyst under operating conditions (p, T). The resulting quantitatively determined partial pressure of the water thus indirectly enables the spatial and temporal conversion of the processes. The knowledge gained from this experimental approach, combined with modelling, allows the design of reactor dimensions under optimized reaction conditions. The good agreement between simulation and experimental neutron imaging warrants the method as a reliable instrument for reactor characterization and design, with the prospect of its application on reactors on the industrial scale.

Growing demand for air travel and limited scalable solutions pose significant challenges to the mitigation of aviation’s climate change impact. Direct air capture (DAC) may gain prominence due to its versatile applications for either carbon removal (direct air carbon capture and storage, DACCS) or synthetic fuel production (direct air carbon capture and utilization, DACCU). Through a comprehensive and time-dynamic techno-economic assessment, we explore the conditions for synthetic fuels from DACCU to become cost-competitive with an emit-and-remove strategy based on DACCS under 2050 CO2 and climate neutrality targets. We find that synthetic fuels could achieve climate neutrality at lower cost than an emit-and-remove strategy due to their ability to cost-effectively mitigate contrails. Under demand reductions, contrail avoidance, and CO2 neutrality targets the cost advantage of synthetic fuels weakens or disappears. Low electricity cost (€0.02 kWh-1) and high fossil kerosene prices (€0.9 l-1) can favor synthetic fuels’ cost-competitiveness even under these conditions. Strategic interventions, such as optimal siting and the elimination of fossil fuel subsidies, can thus favor a shift away from fossil-reliant aviation.