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.

Adjustments of the oxygen diffusing capacity to energetic demands during the development of the quail (Coturnix coturnix japonica).

One of the hypotheses that attempt to explain physiological limitations of energy budgets is the symmorphosis hypothesis, which proposes that if matching structures to functional needs were combined with the strict economy of energy and materials, the result would be an optimal organ design for the specific function it serves. Evidence in favor of symmorphosis in adults is as abundant as evidence against it, but the plasticity of some morphological traits may be dependent on the ontogenetic stage at which acclimation acts. Thus, here we studied the adjustment of structure and function in lungs at different stages of development in the quail Coturnix coturnix japonica under two thermal regimes. Our main results show that i) resting metabolic rate, maximum thermogenic oxygen consumption and oxygen diffusion capacity did not exhibit developmental plasticity for two thermal environments; and ii) oxygen diffusion capacity fully adjusted to resting metabolic rate and maximum oxygen consumption during development. C. coturnix has a low safety factor close to 1 which is consistent with the symmorphosis hypothesis.

Renal effect of gentamicin in diabetic rats.

To evaluate the protective effect of diabetes mellitus (DM) on renal function of rats treated with gentamicin (GM), male Wistar-EPM rats (250-350 g) were treated with streptozotocin (SZ; 45 mg/kg) and starting 10 days after induction of diabetes, GM was given for ten consecutive days at a daily dose of 40 mg/kg. In the GM-treated group (G), a significant fall in inulin and sodium-p-amino-hippurate clearance was obtained (3.57 +/- 0.16 and 12.59 +/- 0.61 ml min-1 kg-1 vs 6.43 +/- 0.21 and 17.98 +/- 0.47 ml min-1 kg-1 in control rats (C), respectively) while in the animals previously injected with SZ (diabetic+gentamicin, DG group) these changes were not observed. The diabetic (D), G and DG groups showed a significant rise in urinary flow compared to C (0.165 +/- 0.009, 0.145 +/- 0.007 and 0.173 +/- 0.009 ml min-1 kg-1 vs 0.109 +/- 0.003 ml min-1 kg-1, respectively); however, only in G was the U/P inulin ratio significantly decreased when compared to C. The fractional excretion (FE) of sodium and potassium was significantly augmented in G when compared to C, D and DG. Thus, diabetes protected against gentamicin nephrotoxicity at both the glomerular and tubular level, although it did not promote a reduction in urinary flow.

Renal effect of gentamicin in diabetic rats

To evaluate the protective effect of diabetes mellitus (DM) on renal function of rats treated with gentamicin (GM), male Wistar-EPM rats (250-350 g) were treated with streptozotocin (SZ; 45 mg/kg) and starting 10 days after induction of diabetes, GM was given for ten consecutive days at a daily dose of 40 mg/kg. In the GM-treated group (G), a significant fall in inulin and sodium-p-aminohippurate clearance was obtained (3.57 + or - 0.16 and 12.59 + or - 0.61 ml min-1kg-1 vs 6.43 + or - 0.21 and 17.98 + or - 0.47 ml min-1 kg-1 in control rats (C), respectively) while in the animals previously injected with SZ (diabetic + gentamicin, DG group) these changes injected with SZ (diabetic + gentamicin, DG group) these changes were not observed. The diabetic (D), g and DG group showed a significant rise in urinary flow compared to C (0.165 + or - 0.009, 0.145 + or - 0.007 and 0.173 + or - 0.009 ml min-1kg-1 vs 0.109 + or - 0.003 ml min-1kg-1, respectively); however, only in G was the U/P inulin ration significantly decreased when compared to C. The fractional excretion (FE) of sodium and postassium was significantly augmented in G when compared to C, D and DG. Thus, diabetes protected against gentamicin nephrotoxicity at both the glomerular and tubular level, although it did not promote a reduction in urinary flow