Quantification of the composition of pyrolysis oils of complex plastic waste by gas chromatography coupled with mass spectrometer detector.

Waste valorisation through pyrolysis generates solid, liquid and gaseous fractions that need to be deeply characterised in order to try to recover secondary raw materials or chemicals. Depending on the waste and the process conditions, the liquid fraction obtained (so-called pyrolysis oil) can be very complex. This work proposes a method to quantitatively measure the composition of pyrolysis oils coming from three types of polymeric waste: (1) plastic packaging from sorting plants of municipal solid waste, (2) plastic rich fractions rejected from sorting plants of waste of electrical and electronic equipment and (3) end-of-life carbon/glass fibre reinforced thermoset polymers. The proposed methodology uses a gas chromatography (GC) coupled with mass spectrometer detector (MS) analytical technique, a certified saturated alkanes' mix, an internal standard and fourteen model compounds. Validation of the methodology concluded that the average relative error was between -59 wt% and +62 wt% (with standard deviations between 0 wt% and 13 wt%). Considering that the state-of-the-art scenario to quantify complex plastic pyrolysis oils as a whole is almost none and that they are usually evaluated only qualitatively based on the area percentage of the GC-MS chromatograms, the presented quantification methodology implies a clear step forward towards complex pyrolysis oil compositional quantification in a cost-effective way. Besides, this quantification methodology enables determining what proportion is being detected by GC-MS with respect to the total oil. Finally, the presented work includes all the Kováts RI for complex temperature-program gas chromatography of all the signals identified in the analysed pyrolysis oils, to be readily available to other researchers towards the identification of chemical compounds in their studies.

Composite waste recycling: Predictive simulation of the pyrolysis vapours and gases upgrading process in Aspen plus.

Waste generation is one of the greatest problems of present times, and the recycling of carbon fibre reinforced composites one big challenge to face. Currently, no resin valorisation is done in thermal fibre recycling methods. However, when pyrolysis is used, additional valuable compounds (syngas or H2-rich gas) could be obtained by upgrading the generated vapours and gases. This work presents the thermodynamic and kinetic multi-reaction modelling of the pyrolysis vapours and gases upgrading process in Aspen Plus software. These models forecast the theoretical and in-between scenario of a thermal upgrading process of an experimentally characterised vapours and gases stream (a blend of thirty-five compounds). Indeed, the influence of temperature (500 °C-1200 °C) and pressure (ΔP = 0, 1 and 2 bar) operating parameters are analysed in the outlet composition, residence time and possible reaction mechanisms occurring. Validation of the kinetic model has been done comparing predicted outlet composition with experimental data (at 700 °C and 900 °C with ΔP = 0 bar) for H2 (g), CO (g), CO2 (g), CH4 (g), H2O (v) and C (s). Kinetic and experimental results show the same tendency with temperature, validating the model for further research. Good kinetic fit is obtained for H2 (g) (absolute error: 0.5 wt% at constant temperature and 0.3 wt% at variable temperature) and H2O (v) shows the highest error at variable T (8.8 wt%). Both simulation and experimental results evolve towards simpler, less toxic and higher generation of hydrogen-rich gas with increasing operating temperature and pressure.

Estudio ADENI-UCI: Análisis de las decisiones de no ingreso en UCI como medida de limitación de los tratamientos de soporte vital / ADENI-UCI Study: Analysis of non-income decisions in ICU as a measure of limitation of life support treatments

Objetivo: Analizar las variables asociadas a las decisiones de rechazo al ingreso en una Unidad de Cuidados Intensivos (UCI) como medida de limitación de tratamiento de soporte vital. Diseño: Prospectivo, multicéntrico. Ámbito: Sesenta y dos UCI de España entre febrero de 2018 y marzo de 2019. Pacientes: Mayores de 18 años a los que se les negó el ingreso a una UCI como medida de limitación de tratamiento de soporte vital. Intervenciones: Ninguna. Variables de interés principals: Comorbilidades de los pacientes, situación funcional previa medida por la escala KNAUS y Karnosfky; escalas pronósticas de Lee y Charlson; gravedad del enfermo medida por las escalas APACHE II y SOFA, motivo que justifica la toma de la decisión, persona a la cual es trasmitida la información; fecha de alta o fallecimiento intrahospitalario, destino al alta hospitalaria. Resultados: Se registraron un total de 2.312 decisiones de no ingreso como medida de limitación del tratamiento de soporte vital (LTSV), de las cuales se analizaron 2.284. El principal motivo de consulta fue la insuficiencia respiratoria (1.080 [47,29%]). La pobre calidad de vida estimada de los enfermos (1.417 [62,04%]), la presencia de una enfermedad crónica grave (1.367 [59,85%]) y la limitación funcional previa de los pacientes (1.270 [55,60%]) fueron los principales motivos esgrimidos para denegar el ingreso. La tasa de mortalidad intrahospitalaria fue del 60,33%. La futilidad del tratamiento se constató como factor de riesgo asociado a mortalidad (OR: 3,23; IC 95%: 2,62-3,99). Conclusiones: Las decisiones para limitar el ingreso en UCI como medida de LTSV se basan en los mismos motivos que las decisiones tomadas dentro de la UCI. La futilidad valorada por el intensivista se relaciona adecuadamente con el resultado final de muerte (AU)

Objective: To analyze the variables associated with ICU refusal decisions as a life support treatment limitation measure. Design: Prospective, multicentrico. Scope: 62 ICU from Spain between February 2018 and March 2019. Patients: Over 18 years of age who were denied entry into ICU as a life support treatment limitation measure. Interventions: None. Main interest variables: Patient comorities, functional situation as measured by the KNAUS and Karnosfky scale; predicted scales of Lee and Charlson; severity of the sick person measured by the APACHE II and SOFA scales, which justifies the decision-making, a person to whom the information is transmitted; date of discharge or in-hospital death, destination for hospital discharge. Results: A total of 2312 non-income decisions were recorded as an LTSV measure of which 2284 were analyzed. The main reason for consultation was respiratory failure (1080 [47.29%]). The poor estimated quality of life of the sick (1417 [62.04%]), the presence of a severe chronic disease (1367 [59.85%]) and the prior functional limitation of patients (1270 [55.60%]) were the main reasons for denying admission. The in-hospital mortality rate was 60.33%. The futility of treatment was found as a risk factor associated with mortality (OR: 3.23; IC95%: 2.62-3.99). Conclusions: Decisions to limit ICU entry as an LTSV measure are based on the same reasons as decisions made within the ICU. The futility valued by the intensivist is adequately related to the final result of death (AU)

Production of hydrogen-rich gases in the recycling process of residual carbon fiber reinforced polymers by pyrolysis.

In this work, a novel method to valorize the polymeric matrix of residual carbon fiber reinforced polymers (CFRP) in the recycling process of carbon fibers by pyrolysis is presented. The experiments have been carried out with an expired epoxy-based pre-preg and in a lab-scale installation composed of two reactors. In the first one, pyrolysis and oxidation have been carried out, while in the second one, the gases and vapors resulting from the thermal decomposition of the polymeric resin have been thermally treated. The following operating parameters have been studied in the pyrolysis step: dwell time, the use of N2 (N2 flow, no N2 flow and not even to inert the reaction medium) and the solid bed material of the second reactor. In the oxidation step, temperature and time have been optimized by using the theory of experiments based on 2 k factorial design was used. It has been demonstrated that clean carbon fibers and a gaseous fraction with 75% by volume of H2 can be obtained. This is possible through a combined process of (1) CFRP thermal decomposition at 500 °C, (2) thermal treatment of gases and vapors at 900 °C in a solid bed tubular reactor filled with a waste refractory material and (3) oxidation of pyrolysis solid at 500 °C during 165 min in presence of 1.3 L air min-1.

Linking the scientific knowledge on marine frontal systems with ecosystem services.

Primary production hotspots in the marine environment occur where the combination of light, turbulence, temperature and nutrients makes the proliferation of phytoplankton possible. Satellite-derived surface chlorophyll-a distributions indicate that these conditions are frequently associated with sharp water mass transitions named "marine fronts". Given the link between primary production, consumers and ecosystem functions, marine fronts could play a key role in the production of ecosystem services (ES). Using the shelf break front in the Argentine Sea as a study case, we show that the high primary production found in the front is the main ecological feature that supports the production of tangible (fisheries) and intangible (recreation, regulation of atmospheric gases) marine ES and the reason why the provision of ES in the Argentine Sea concentrates there. This information provides support to satellite chlorophyll as a good indicator of multiple marine ES. We suggest that marine fronts could be considered as marine ES hot spots.

Young green turtles, Chelonia mydas, exposed to plastic in a frontal area of the SW Atlantic.

Ingestion of anthropogenic debris represents an important threat to marine turtle populations. Information has been limited to inventories of debris ingested and its consequences, but why ingestion occurs and the conditions that enable it are less understood. Here we report on the occurrence of plastic ingestion in young green turtles (Chelonia mydas) inhabiting the Río de la Plata (SW Atlantic). This estuarine area is characterized by a frontal system that accumulates anthropogenic debris. We explored exposure of green turtles to plastic and its ingestion via debris distribution, habitat use and digestive tract examination. Results indicated that there is considerable overlap of frontal accumulated plastic and core foraging areas of the animals. Exposure results in ingestion, as shown by the high frequency of plastic found in the digestive tracts. The Río de la Plata estuarine front is an area of conservation concern for young green turtles.