Ten new insights in climate science 2020 – a horizon scan

Non-technical summary We summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding of Earth's sensitivity to carbon dioxide, finds that permafrost thaw could release more carbon emissions than expected and that the uptake of carbon in tropical ecosystems is weakening. Adverse impacts on human society include increasing water shortages and impacts on mental health. Options for solutions emerge from rethinking economic models, rights-based litigation, strengthened governance systems and a new social contract. The disruption caused by COVID-19 could be seized as an opportunity for positive change, directing economic stimulus towards sustainable investments. Technical summary A synthesis is made of ten fields within climate science where there have been significant advances since mid-2019, through an expert elicitation process with broad disciplinary scope. Findings include: (1) a better understanding of equilibrium climate sensitivity; (2) abrupt thaw as an accelerator of carbon release from permafrost; (3) changes to global and regional land carbon sinks; (4) impacts of climate change on water crises, including equity perspectives; (5) adverse effects on mental health from climate change; (6) immediate effects on climate of the COVID-19 pandemic and requirements for recovery packages to deliver on the Paris Agreement; (7) suggested long-term changes to governance and a social contract to address climate change, learning from the current pandemic, (8) updated positive cost–benefit ratio and new perspectives on the potential for green growth in the short- and long-term perspective; (9) urban electrification as a strategy to move towards low-carbon energy systems and (10) rights-based litigation as an increasingly important method to address climate change, with recent clarifications on the legal standing and representation of future generations. Social media summary Stronger permafrost thaw, COVID-19 effects and growing mental health impacts among highlights of latest climate science

Simultaneous modeling of VLE, LLE and VLLE of CO2 and 1, 2, 3 and 4 alkanol containing mixtures using GC-PPC-SAFT EOS

International audienceA polar version of the group contribution PC-SAFT equation of state (GC-PPC-SAFT; Tamouza et al., 2004; NguyenHuynh et al., 2008) combined with a method for correlation/prediction of binary interaction parameters kij (NguyenHuynh et al., 2008) is here applied to model vapor–liquid, liquid–liquid and vapor–liquid–liquid phase equilibria of CO2 + alkanol mixtures simultaneously.A cross-association interaction between CO2 and alkanol had to be taken into account to model/predict the mixtures equilibria accurately. The cross-association parameters were evaluated using the so-called CR1 mixing rules supported by ab initio computations.Extensive prediction tests on CO2 + alkanol mixtures involving linear and branched alkanols are carried out. The results obtained showed that in most cases, the correlation and prediction calculations are qualitatively and quantitatively satisfactory: the overall deviations on liquid phase and vapor phase are respectively ΔX = 3–4% and ΔY = 1–2%

Photocatalytic Nanoparticulate ZrxTi1-xO2 Coatings with Controlled Homogeneity of Elemental Composition

International audienc

Modeling VLE of H₂ + Hydrocarbon Mixtures Using a Group Contribution SAFT with a <i>k</i>_<i>ij</i> Correlation Method Based on London’s Theory

A group contribution perturbed-chain statistical associating fluid theory (GC-PC-SAFT) equation of state (Tamouza et al. <i>Fluid Phase Equilib</i>. <b>2004</b>, <i>222</i>−<i>223</i>, 67−76) combined with a recent method for correlating <i>k_ij</i> using only pure compound parameters (NguyenHuynh et al. <i>Ind. Eng. Chem. Res.</i>, <b>2008</b>. <i>47(22)</i>, 8847−8858) is extended here to model vapor−liquid phase equilibria of H₂ + alkanes and H₂ + aromatics mixtures. The correlation of <i>k_ij</i> is inspired by London’s theory of dispersive interactions, and uses “pseudo-ionization energies” <i>J</i>_<i>i</i> and <i>J</i>_<i>j</i> of compounds <i>i</i> and <i>j</i> as adjustable parameters. The GC-PC-SAFT parameters for alkanes and aromatics were reused from previous works when available. Otherwise, the missing parameters were estimated by regression of corresponding pure vapor−liquid equilibrium (VLE) data. Those of H₂ were determined in this work by correlating some VLE data of H₂ + n-alkane systems. Using the parameters thus obtained, the phase envelopes of other H₂ + alkane and H₂ + aromatic systems were fully predicted. The prediction tests were as comprehensive as possible. Correlations and predictions are qualitatively and quantitatively satisfactory. The deviations are within 5−6%, that is, comparable to those obtained on previously investigated systems. Mixtures containing H₂ are modeled here with deviations that compare well with those of the Grayson−Streed model (Grayson, H.G.; Streed, C.W.; <i>Proc., 6</i>^<i>th</i> <i>World Pet. Congress</i>, 1963, 169−181), which is often used by process engineers for hydrogen and hydrocarbon mixtures