The environmental impact of fluorinated gases (F-gases) necessitates the development of green technologies to mitigate them. Fluorinated ionic liquids (FIL/ILs) emerged as an alternative absorbent ...due to their unique and exceptional properties. In this work, a COSMO-based/Aspen Plus methodology was used to evaluate the performance of FIL/ILs as absorbents in the process scale of two F-gases: 1,1,1,2-tetrafluoroethane (R-134a) and difluoromethane (R-32). Results of the absorption column in equilibrium mode revealed that the behavior of FIL/ILs is similar under the same conditions, reaching higher efficiencies in the case of absorbing R-134a at a high F-gas partial pressure. Rate-based calculations in packing column demonstrated a kinetic control with highly viscous FIL/ILs, revealing higher performance differences between FIL/IL absorbents. The regeneration stage was also evaluated in near-industrial conditions. Operating conditions of the absorption column were optimized with a column of height 10 m and diameter ranging from 1.1 to 1.2 m at 10 bar total pressure, reaching 90% F gas recovery with an L/G range of 6–10. Finally, preliminary economic analysis revealed operating costs to recover 90% of F-gas of 70 $/ton (R-134a) and 130 $/ton (R-32) with the FIL/IL that revealed the best behavior, 1-ethyl-3-methylimidazolium triflate.
Recent advances in ultrasound technology have made modern handheld ultrasound devices and are contributing to make bedside ultrasound evaluation a practice available to all physicians. A 46‐year‐old ...woman with history of systemic erythematosus presented to our hospital with 14 days of COVID‐19. The patient suddenly presented greater respiratory distress, tachycardia, hypotension, and increased supplemental oxygen requirements; so she required mechanical ventilation. Point‐of‐care ultrasound assessment with handheld ultrasound device was observed on the apical view an apical thrombus in the right ventricle, McConnell's sign. The patient underwent systemic thrombolysis with alteplase showing improvement in mechanical ventilation parameters and is currently continuing treatment for COVID‐19 in the intensive care unit of our hospital. Emerging technologies such as handheld ultrasound devices can provide high‐quality care to the patients. Routine screening of patients with COVID‐19 using handheld ultrasound is feasible, may be able to define prognosis and treatment of cardiovascular complications.
We present the image of a clinical case of right ventricular thrombus in a patient with COVID‐19, documented with portable ultrasound equipment connected to a cellular phone.
In recent years, the fight against climate change and the mitigation of the impact of fluorinated gases (F-gases) on the atmosphere is a global concern. Development of technologies that help to ...efficiently separate and recycle hydrofluorocarbons (HFCs) at the end of the refrigeration and air conditioning equipment life is a priority. The technological development is important to stimulate the F-gas capture, specifically difluoromethane (R-32) and 1,1,1,2-tetrafluoroethane (R-134a), due to their high global warming potential. In this work, the COSMO-RS method is used to analyze the solute–solvent interactions and to determine Henry’s constants of R-32 and R-134a in more than 600 ionic liquids. The three most performant ionic liquids were selected on the basis of COSMO-RS calculations, and F-gas absorption equilibrium isotherms were measured using gravimetric and volumetric methods. Experimental results are in good agreement with COSMO-RS predictions, with the ionic liquid tributyl(ethyl)phosphonium diethyl phosphate, P2444C2C2PO4, being the salt presenting the highest absorption capacities in molar and mass units compared to salts previously tested. The other two ionic liquids selected, trihexyltetradecylphosphonium glycinate, P66614C2NO2, and trihexyl(tetradecyl)phosphonium 2-cyano-pyrrole, P66614CNPyr, may be competitive as far as their absorption capacities are concerned. Future works will be guided on evaluating the performance of these ionic liquids at an industrial scale by means of process simulations, in order to elucidate the role in process efficiency of other relevant absorbent properties such as viscosity, molar weight, or specific heat.
The increasing awareness of the environmental impact of fluorinated gases (F-gases) used in refrigeration is instigating the development of technologies to recover and recycle them. With this goal in ...mind, single-component absorption equilibrium isotherms at 303.15 K of F-gases in different ionic liquids (ILs) were determined using a gravimetric method. The selected F-gases are the most used in domestic refrigeration (R-32: difluoromethane, R-125: pentafluoroethane, and R-134a: 1,1,1,2-tetrafluoroethane). The results show that ILs containing a fluorinated alkyl side chain with four carbon atoms, that is, fluorinated ILs (FILs), have higher gas absorption capacity than conventional fluoro-containing ILs. All studied ILs showed ideal selectivity toward R-134a. Conventional fluoro-containing ILs showed better selectivities for the separation of the binary mixtures R-134a/R-125 and R-32/R-125, and FILs showed better selectivities for the R-134a/R-32 mixture. These results provide fundamental knowledge of the behavior of these new alternative solvents and key information for their application in the separation of F-gas mixtures of commercial refrigerants.
According to the Food and Agriculture Organization of the United Nations, the world population will reach nine billion people in 2050, of which 75% will live in urban settlements. One of the biggest ...challenges will be meeting the demand for food, as farmland is being lost to climate change, water scarcity, soil pollution, among other factors. In this context, hydroponics, an agricultural method that dispenses with soil, provides a viable alternative to address this problem. Although hydroponics has proven its effectiveness on a large scale, there are still challenges in implementing this technique on a small scale, specifically in urban and suburban settings. Also, in rural communities, where the availability of suitable technologies is scarce. Paradigms such as the Internet of Things and Industry 4.0, promote Precision Agriculture on a small scale, allowing the control of variables such as pH, electrical conductivity, temperature, among others, resulting in higher production and resource savings.
The environmental impact resulting from the release of fluorinated gases (F-gases), commonly used in refrigeration, is prompting the development of technologies to recover and recycle them. ...Fluorinated ionic liquids (FILs) have been investigated as promising candidates for the absorption and selective separation of F-gases. In this work, we prepared deep eutectic solvents (DESs) composed of FILs and perfluorinated acids to explore the excellent gas solubilization properties of FILs with high melting points in a wider liquid range. A screening of DESs prepared from five different FILs was performed for the solubilization of 1,1,1,2-tetrafluoroethane (R-134a) at 303.15 K, using a stainless steel volumetric system. N4444C4F9SO3/C4F9CO2H and C2C1ImC8F17SO3/C4F9CO2H were selected as the systems with the best absorption capacities and were studied in three different molar ratios of FIL/perfluorinated acid. Then, the absorption of difluoromethane (R-32), pentafluoroethane (R-125), and R-134a were determined at 303.15, 313.15, and 323.15 K. All studied DESs have high selectivity for the separation of R-134a from their mixtures with the other two F-gases. The results presented here provide knowledge of the behavior of these new alternative solvents for the separation of F-gases from commercial refrigerants, at three different temperatures, and in a wide range of operating pressures.
PDF
