68 research outputs found

    Thermal Methane Cracking on Molten Metal: Techno-economic Assessment

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    Close to 80% of hydrogen is currently produced through emissions-intensive natural gas reforming and coal gasification, with almost all the rest being by-product hydrogen produced in facilities designed for other products. To significantly contribute to the clean energy transition, it is critical to develop low-carbon hydrogen production routes that can replace current production and at the same time expand production capacity to meet new demands. The two main low-carbon production routes are Steam Methane Reforming coupled with CCUS (blue H2) or water electrolysis (green H2); however, a new path based on methane pyrolysis is becoming more and more interesting in the last years. This process involves producing H2 with solid carbon instead of CO2 (turquoise H2). The aim of this article is to present a new scheme for Hydrogen production through the cracking of methane using renewable energy. The process is based on a molten metal reactor where the main reaction takes place inside the liquid bath: the molten metal bath in fact enhances heat transfer and can facilitate carbon removal. A techno-economic assessment for distributed H2 is analysed and reported. Finally, methane cracking performances are compared to conventional H2 production processes

    Regeneration of Exhausted Palladium-Based Membranes: Recycling Process and Economics

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    The aim of the present work is the recycling treatment of tubular α-Al2O3-supported ceramic membranes with a Pd/Ag selective layer, employed in hydrogen production with integrated CO2 capture. A nitric acid leaching treatment was investigated, and recovered ceramic supports were characterized, demonstrating their suitability for the production of novel efficient membranes. The main objective was the metal dissolution that preserved the support integrity in order to allow the recovered membrane to be suitable for a new deposition of the selective layer. The conditions that obtained a satisfactory dissolution rate of the Pd/Ag layer while avoiding the support to be damaged are as follows: nitric acid 3 M, 60 °C and 3.5 h of reaction time. The efficiency of the recovered supports was determined by nitrogen permeance and surface roughness analysis, and the economic figures were analysed to evaluate the convenience of the regeneration process and the advantage of a recycled membrane over a new membrane. The experimentation carried out demonstrates the proposed process feasibility both in terms of recycling and economic results.This research has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 760944 (MEMBER project)

    Nutrition therapy for critically ill patients across the Asia-Pacific and Middle East Regions: a consensus statement

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    Background & Aims: Guidance on managing the nutritional requirements of critically ill patients in the intensive care unit (ICU) has been issued by several international bodies. While these guidelines are consulted in ICUs across the Asia Pacific and Middle East, there is little guidance available that is tailored to the unique healthcare environments and demographics across these regions. Furthermore, the lack of consistent data from randomized controlled clinical trials, reliance on expert consensus, and differing recommendations in international guidelines necessitate further expert guidance on regional best practice when providing nutrition therapy for critically ill patients in ICUs in Asia Pacific and the Middle East. Methods: The Asia-Pacific and Middle East Working Group on Nutrition in the ICU has identified major areas of uncertainty in clinical practice for healthcare professionals providing nutrition therapy in Asia Pacific and Middle East and developed a series of consensus statements to guide nutrition therapy in the ICU in these regions. Results: Accordingly, consensus statements have been provided on nutrition risk assessment and parenteral and enteral feeding strategies in the ICU, monitoring adequacy of, and tolerance to, nutrition in the ICU and institutional processes for nutrition therapy in the ICU. Furthermore, the Working Group has noted areas requiring additional research, including the most appropriate use of hypocaloric feeding in the ICU. Conclusions: The objective of the Working Group in formulating these statements is to guide healthcare professionals in practicing appropriate clinical nutrition in the ICU, with a focus on improving quality of care, which will translate into improved patient outcomes

    Attosecond state-resolved carrier motion in quantum materials probed by soft x-ray XANES

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    Recent developments in attosecond technology led to table-top x-ray spectroscopy in the soft x-ray range, thus uniting the element- and state-specificity of core-level x-ray absorption spectroscopy with the time resolution to follow electronic dynamics in real-time. We describe recent work in attosecond technology and investigations into materials such as Si, SiO2, GaN, Al2O3, Ti, and TiO2, enabled by the convergence of these two capabilities. We showcase the state-of-the-art on isolated attosecond soft x-ray pulses for x-ray absorption near-edge spectroscopy to observe the 3d-state dynamics of the semi-metal TiS2 with attosecond resolution at the Ti L-edge (460 eV). We describe how the element- and state-specificity at the transition metal L-edge of the quantum material allows us to unambiguously identify how and where the optical field influences charge carriers. This precision elucidates that the Ti:3d conduction band states are efficiently photo-doped to a density of 1.9 x 1021 cm 3. The light-field induces coherent motion of intra-band carriers across 38% of the first Brillouin zone. Lastly, we describe the prospects with such unambiguous real-time observation of carrier dynamics in specific bonding or anti-bonding states and speculate that such capability will bring unprecedented opportunities toward an engineered approach for designer materials with pre-defined properties and efficiency. Examples are composites of semiconductors and insulators like Si, Ge, SiO2, GaN, BN, and quantum materials like graphene, transition metal dichalcogens, or high-Tc superconductors like NbN or LaBaCuO. Exiting are prospects to scrutinize canonical questions in multi-body physics, such as whether the electrons or lattice trigger phase transitions

    Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

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    Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
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