Green hydrogen is central to the energy transition, but its production often requires expensive materials and poses environmental risks due to the perfluorinated substances used in electrolysis. This study introduces a transformative approach to green hydrogen production via chemical looping, utilizing an iron-based oxygen carrier with yttrium-stabilized zirconium oxide (YSZ). A significant innovation is the replacement of Al₂O₃ with SiO₂ as an inert support pellet, enhancing process efficiency and reducing CO₂ contamination by minimizing carbon deposition by up to 700%. The major findings include achieving a remarkable hydrogen purity of 99.994% without the need for additional purification methods. The Fe-YSZ oxygen carrier possesses a significantly higher pore volume of 323 mm³/g and pore surface area of 18.3 m²/g, increasing the pore volume in the iron matrix by up to 50%, further improving efficiency. The catalytic system exhibits a unique self-cleaning effect, substantially reducing CO₂ contamination. Fe-YSZ-SiO₂ demonstrated CO₂ contamination levels below 100 ppm, which is particularly noteworthy. This research advances our understanding of chemical looping mechanisms and offers practical, sustainable solutions for green hydrogen production, highlighting the crucial synergy between support pellets and oxygen carriers. These findings underscore the potential of chemical looping hydrogen (CLH) technology for use in efficient and environmentally friendly hydrogen production, contributing to the transition to cleaner energy sources.

Tampons are widely used hygiene products, yet there remains a lack of engineering-focused research on their design and functionality. A critical factor in tampon performance is the pore structure of the material, which directly influences liquid absorption. While micro-computed tomography has provided valuable insights into overall pore volume, it falls short in accurately characterizing individual pore sizes. In this study, we employ the sub-network of an over-segmented watershed (SNOW) algorithm alongside PoreSpy to obtain a detailed pore size distribution within tampon proxy materials. Our findings reveal that tampon proxies made of trilobal cellulose viscose fibres exhibit significantly larger pores, with a 26-32% higher pore equivalent diameter (PED), than their round-fibre counterparts, despite comparable porosity, highlighting the influence of fibre geometry on expansion and liquid uptake. Although trilobal CV tampon proxies exhibit a 41% greater expanded volume and 18.7% higher absorbency compared to round fibres, their porosity increases only moderately, underscoring the need to investigate pore structure beyond bulk metrics. Kolmogorov–Smirnov distance analyses confirm that inter-fibre differences in pore structure exceed intra-sample variations, underlining the dominant role of fibre type on absorbency. While gradients along the tampon proxy length influence local pore formation, trilobal fibre tampon proxies consistently form larger pores, enhancing their liquid absorption properties. Additionally, we observe a systematic increase in pore size from top to bottom, likely influenced by one-sided liquid application and compression effects during production. These results offer a more detailed understanding of the mechanisms governing pore formation in tampon networks and provide a basis for future simulations of liquid imbibition, ultimately contributing to optimized tampon designs

The sorption and release of gases in complex porous materials often involves multiple simultaneous processes. It is difficult to distinguish the dynamics of individual processes from experiments that only allow access to the combined overall dynamics of all processes taking place. This works shows for the case of dimethyl sulfoxide (DMSO) vapor interacting with paper as a porous matrix that it is possible to distinguish experimentally the dynamics of the sorption and release processes of two populations of differently sorbed DMSO molecules, even though the temporal evolution of the sorbed concentration shows no evidence of multiple processes. The key to separating the processes lies in the release behavior. DMSO release from paper saturated with DMSO is a superposition of short- and long-term processes, with release rates of 3 $$\times$$ 10 $$^{-4}$$ s $$^{-1}$$ and 1.1 $$\times$$ 10 $$^{-6}$$ s $$^{-1}$$ , respectively. Such different rates indicate the presence of two types of sorbed populations with distinct release dynamics. This inspires a strategy to separate the sorption dynamics of the two populations as well. A sorption experiment was designed to determine the concentration of DMSO sorbed in the paper at a certain exposure time, and again after the short-term release was complete. This procedure yields the concentration of each sorbing species as a function of time. Successfully separating the process dynamics is important for clarifying the nature of the processes, such as determining activation energies, and for correctly describing the temporal evolution of sorption and release mathematically. This strategy may help reveal the dynamics of simultaneous, mutually obscuring processes in other systems as well. Graphical Abstract