Catalytic effect of MCM-41 in the pyrolysis of tobacco and several substances used as additives in the preparation of commercial cigarettes

Comunicación presentada en forma de póster en el "12th Mediterranean Congress of Chemical Engineering", Barcelona (Spain), November 15-18, 2011.

Evolution of extracellular polymeric substances produced in two submerged membrane bioreactors working at high sludge age

This research paper deals with the evolution of the extracellular polymeric substances (EPS) produced in the mixed liquor of two 25 L bench-scale membrane bioreactors (MBRs), with micro (MF-MBR) and ultrafiltration (UF-MBR) submerged membranes. The conclusion focuses on the relationship between the operation and how EPS respond, demonstrating that significant changes in EPS concentration were commonly observed when abrupt changes in the operational conditions took place. Bound EPS (EPSb) showed moderate positive statistical correlations with sludge age and MLSS for the two MBRs. Soluble EPS (EPSs), on the other hand, showed a moderate negative statistical correlation between EPSs with the two parameters analyzed for MF-MBR and no correlation with the UF-MBR was found. With respect to the composition of EPS, EPSb were mostly made up of proteins (44–46%) whereas in EPSs, the three components (proteins, carbohydrates, and humic substances) appeared in approximately the same proportion. The statistical analysis exhibited strong positive correlations between EPSb and their constituents, however for EPSs, the correlation was strong only with carbohydrates and moderate with humic substances.

Kinetic study and thermal decomposition behavior of viscoelastic memory foam

A systematic investigation of the thermal decomposition of viscoelastic memory foam (VMF) was performed using thermogravimetric analysis (TGA) to obtain the kinetic parameters, and thermogravimetric analysis coupled to Fourier Transformed Infrared Spectrometry (TGA-FTIR) and thermogravimetric analysis coupled to Mass Spectrometry (TGA-MS) to obtain detailed information of evolved products on pyrolysis and oxidative degradations. Two consecutive nth-order reactions were employed to correlate the experimental data from dynamic and isothermal runs performed at three different heating rates (5, 10 and 20 K/min) under an inert atmosphere. On the other hand, for the kinetic study of the oxidative decomposition, the data from combustion (synthetic air) and poor oxygen combustion (N2:O2 = 9:1) runs, at three heating rates and under dynamic and isothermal conditions, were correlated simultaneously. A kinetic model consisting of three consecutive reactions presented a really good correlation in all runs. TGA-FTIR analysis showed that the main gases released during the pyrolysis of VMF were determined as ether and aliphatic hydrocarbons, whereas in combustion apart from the previous gases, aldehydes, amines and CO2 have also been detected as the main gases. These results were confirmed by the TGA-MS.