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Herein, a robust microporous aluminum tetracarboxylate framework, MIL‐120(Al)‐AP, (MIL, AP: Institute Lavoisier and Ambient Pressure synthesis, respectively) is reported, which exhibits high CO2 uptake (1.9 mmol g−1 at 0.1 bar, 298 K). In situ Synchrotron X‐ray diffraction measurements together with Monte Carlo simulations reveal that this structure offers a favorable CO2 capture configuration with the pores being decorated with a high density of µ2‐OH groups and accessible aromatic rings. Meanwhile, based on calculations and experimental evidence, moderate host‐guest interactions Qst (CO2) value of MIL‐120(Al)‐AP (−40 kJ mol−1) is deduced, suggesting a relatively low energy penalty for full regeneration. Moreover, an environmentally friendly ambient pressure green route, relying on inexpensive raw materials, is developed to prepare MIL‐120(Al)‐AP at the kilogram scale with a high yield while the Metal‐ Organic Framework (MOF) is further shaped with inorganic binders as millimeter‐sized mechanically stable beads. First evidences of its efficient CO2/N2 separation ability are validated by breakthrough experiments while operando IR experiments indicate a kinetically favorable CO2 adsorption over water. Finally, a techno‐economic analysis gives an estimated production cost of ≈ 13 $ kg−1, significantly lower than for other benchmark MOFs. These advancements make MIL‐120(Al)‐AP an excellent candidate as an adsorbent for industrial‐scale CO2 capture processes. [ABSTRACT FROM AUTHOR]

Several industrial sectors, such as for example cement manufacturers and lime producers, produce so-called “unavoidable” CO2 emissions because these ones are intrinsically linked to the industrial process itself (decarbonation of calcium carbonate). In order to reduce these emissions, it is necessary to implement a Carbon Capture, Utilization and/or Storage (CCUS) process chain, whose step of capture, although already technologically mature (especially the absorption-regeneration process using amine(s)-based solvents), leads to very high energy consumption. Three pathways to reduce this consumption have been investigated (experimentally and/or through the development of Aspen PlusTM simulations), namely: (i) upstream of the process thanks to the increase of the flue gas CO2 content (by partial oxy-combustion and/or flue gas recirculation), (ii) within the process (using more efficient and innovative mixtures of solvents such as demixing solutions), and (iii) at the configurational level by using advanced configurations in the capture process. It emerged that the use of a demixing process such as the mixture composed of diethylethanolamine (DEEA) and methylamino-propylamine (MAPA), or the implementation of an advanced process configuration (InterCooling Absorber + Rich Vapor Compression + Rich Solvent Splitting and Preheating, with methyldiethanolamine (MDEA) + piperazine (PZ) as a solvent) are the most energy reducing pathways for the absorption-regeneration process, i.e. more than 40% in comparison with a conventional process using monoethanolamine (MEA). Moreover, from an economical point of view, and compared to a basic configuration with MEA, the demixing technology has the advantage of being able to achieve such energy performance with a more limited investment (CAPEX) (+1.6%) than with advanced process configurations (+8.8%).

Fouling is one of the barriers to developing more efficient and near-zero emission internal combustion engines. The micron-sized particulate matter is one of the roots of this fouling phenomenon in exhaust gas recirculation (EGR) coolers. This fouling is inadequately evaluated quantitatively, and its deposition mechanism is unknown. To investigate the effect of gravity on the deposition of micron-sized particles, an original nondestructive sampling fouling method and experiment apparatus have been developed to effectively obtain the upper and lower bottom fouling in the cooler in the direction of airflow, and the area proportion, count, and diameter of large particles in the fouling using image processing software. It was found that (i) the area proportion of large particles in the lower bottom fouling was almost 2.5 times higher than the upper bottom fouling; (ii) the count of large particles in the lower bottom fouling was higher, and the maximum diameter was larger, up to 639mm; (iii) the mass of the lower bottom fouling was 1.5 times higher than the upper bottom fouling; (iv) gravity can significantly promote the deposition of micron-sized particles and should be considered in the design and arrangement of the EGR cooler to prevent fouling. [ABSTRACT FROM AUTHOR]

Iron(III) carboxylate based metal organic frameworks (MOFs)/porous coordination polymers (PCPs) have sparked great interest owing to their high structural diversity and tunable porosity, excellent stability, tailored functionality and their scalability as well as green synthesis associated with their biocompatible and biodegradable character. Herein, we present a new robust Fe(III) based PCP (labelled MIL-178(Fe)) built up from chains of corner sharing Fe octahedra interconnected by 1,2,4-benzene tricarboxylic acid, delimiting one dimensional narrow pore channels (pore diameter < 4.5 Å) decorated with polar groups (μ2-OH and --CO2H functions). These structural and chemical features are suitable for the selective adsorption of CO2. MIL-178(Fe) was synthesized following a simple and green protocol in water under near ambient conditions using non-toxic reactants, allowing the production of sub-micrometer sized MIL-178(Fe) particles in a large amount (30 g). As shown by single-gas isotherms and CO2/N2 co-adsorption experiments as well as molecular simulations, this material exhibits a moderate CO2 capacity at low pressure but a high CO2/N2 selectivity. This is fully consistent with the presence of μ2-OH groups acting as CO2 adsorption sites, as revealed from both molecular simulations and in situ PXRD experiments. Finally, the good compatibility of this MOF with the elastomer block copolymer Pebax®-3533 allowed the processing of homogeneous and defect-free mixed matrix membranes with a MIL-178(Fe) loading of up to 25 wt% that outperformed pure Pebax®-3533 membranes for CO2/N2 separation. [ABSTRACT FROM AUTHOR]