Upgrading Pyrolytic Oil via Catalytic Co-Pyrolysis of Beechwood and Polystyrene.

This study aims to investigate the catalytic co-pyrolysis of beech wood with polystyrene as a synergic and catalytic effect on liquid oil production. For this purpose, a tubular semi-continuous reactor under an inert nitrogen atmosphere was used. Several zeolite catalysts were modified via incipient wetness impregnation using iron and/or nickel. The liquid oil recovered was analyzed using GC-MS for the identification of the liquid products, and GC-FID was used for their quantification. The effects of catalyst type, beechwood-to-polystyrene ratio, and operating temperature were investigated. The results showed that the Fe/Ni-ZSM-5 catalyst had the best deoxygenation capability. The derived oil was mainly constituted of aromatics of about 92 wt.% for the 1:1 mixture of beechwood and polystyrene, with a remarkably high heating value of around 39 MJ/kg compared to 18 MJ/kg for beechwood-based bio-oil. The liquid oil experienced a great reduction in oxygen content of about 92% for the polystyrene-beechwood 50-50 mixture in comparison to beechwood alone. The catalytic and synergetic effects were more realized for high beechwood percentages as a 75-25 beechwood-polystyrene mix. Regarding the temperature variation between 450 and 600 °C, the catalyst seemed to deactivate faster at higher temperatures, thus constituting a quality reduction in the pyrolytic oil in high-temperature ranges.

Development of two-dimensional gas chromatography (GC×GC) coupled with Orbitrap-technology-based mass spectrometry: Interest in the identification of biofuel composition.

Comprehensive gas chromatography (GC) has emerged in recent years as the technique of choice for the analysis of volatile and semivolatile compounds in complex matrices. Coupling it with high-resolution mass spectrometry (MS) makes a powerful tool for identification and quantification of organic compounds. The results obtained in this study showed a significant improvement by using GC×GC-EI-MS in comparison with GC-EI-MS; the separation of chromatogram peaks was highly improved, which facilitated detection and identification. However, the limitation of Orbitrap mass analyzer compared with time-of-flight analyzer is the data acquisition rate; the frequency average was about 25 Hz at a mass resolving power of 15.000, which is barely sufficient for the proper reconstruction of the narrowest chromatographic peaks. On the other hand, the different spectra obtained in this study showed an average mass accuracy of about 1 ppm. Within this average mass accuracy, some reasonable elemental compositions can be proposed and combined with characteristic fragment ions, and the molecules can be identified with precision. At a mass resolving power of 7.500, the scan rate reaches 43 Hz and the GC×GC-MS peaks can be represented by more than 10 data points, which should be sufficient for quantification. The GC×GC-MS was also applied to analyze a cellulose bio-oil sample. Following this, a highly resolved chromatogram was obtained, allowing EI mass spectra containing molecular and fragment ions of many distinct molecules present in the sample to be identified.

Removal of hazardous chlorinated VOCs over Mn-Cu mixed oxide based catalyst.

MnCuO(x)/TiO(2) supported catalyst was synthesized by the incipient wetness impregnation method. The catalyst was then tested for the oxidation of chlorobenzene (CB) used as a Cl-VOC model. The results showed that MnCuO(x)/TiO(2) is very active for CB oxidation since a total conversion (exclusively into H(2)O, CO(2) and Cl(2)) was reached at 350 degrees C without formation of any other harmful organic compounds and no catalyst deactivation was observed. This performance was attributed to the formation Mn(1.6)Cu(1.4)O(4) spinel phase. However, at lower temperatures, some deactivation occurred before a steady-state is reached. At 300 degrees C, the CB conversion decreased and stabilised at 75% after 5h and a small amount of HCl and traces of CO were detected. The reason why HCl was not detected at temperatures higher than 350 degrees C was explained by Deacon reaction. SEM/EDS analysis revealed the presence of chlorine uniformly dispersed on the catalyst surface. The formation of chlorinated compound (MnCuO(x-a)Cl(2a)/TiO(2)), which is presumed to be responsible of the catalyst partial deactivation, was confirmed by other analysis experiments (TG/DTA, TPR). The catalyst regeneration under air at 350 degrees C allowed the system to recover the initial activity in spite of the fact that the chlorine was not completely removed from the catalyst.