Pyrolysis

nassar's picture

Thermogravimetric Studies on Catalytic ‎Effect of Metal Oxide Nanoparticles on ‎Asphaltene Pyrolysis Under Inert ‎Conditions

Journal Title, Volume, Page: 
Journal of Thermal Analysis and Calorimetry, Volume 110, Issue 3, pp 1327-133
Year of Publication: 
2012
Authors: 
Nashaat N. Nassar
Department of Chemical & Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada
Current Affiliation: 
Department of Chemical Engineering, Faculty of Engineering and Information Technology, An-Najah National University, Nablus, Palestine
Azfar Hassan
Department of Chemical & Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada
Pedro Pereira-Almao
Department of Chemical & Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada
Preferred Abstract (Original): 

This study investigated the catalytic effect of NiO, Co3O4 and Fe3O4 nanoparticles toward asphaltene thermal decomposition (pyrolysis) under inert conditions. Asphaltene adsorbed onto the selected nanoparticles were subjected to thermal decomposition up to 800 °C in a thermogravimetric analyzer. The presence of nanoparticles caused a significant decrease in the asphaltene decomposition temperature and activation energy. Activation energies for the process were calculated using the Ozawa–Flynn–Wall method. All the selected metal oxide nanoparticles showed high catalytic activity toward asphaltene decomposition in the following order NiO > Co3O4 > Fe3O4. This study confirms that metal oxide nanoparticles can significantly enhance the thermal decomposition of heavy hydrocarbons, like asphaltenes.

sjodeh's picture

Electrically Conducting Thin Films Obtained by Ion Implantation in Pyrolyzed ‎Polyacrylonitrile

Journal Title, Volume, Page: 
Material Research Innovations, Volume 4, Issue 2-3, pp 131-134
Year of Publication: 
2001
Authors: 
S. Jodeh
General Motors Research and Development, 30500 Mound Road, Warren, MI 48090-9055, USA
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
R. A. Basheer
General Motors Research and Development, 30500 Mound Road, Warren, MI 48090-9055, USA
Preferred Abstract (Original): 

Heat treatment of polyacrylonitrile (PAN) leads to products with semiconductor-to-metal range of conductivities. The electrical properties of these materials are further modified by ion implantation. The conductivity, 1×10–7 (Ω cm)–1, of heat treated PAN at 435°C (PAN435) increases upon ion implantation with As+, Kr+, Cl+ or F+, reaching the maximum value of 8.9×10–1 (Ω cm)–1 at a dose of 5×1016 ion/cm2 and an energy of 200 KeV for the case of F+ implantation. On the other hand, ion implantation in the more conducting heat-treated PAN at 750 °C (PAN750) leads to a decrease in the electrical conductivity. It is shown that the conductivity modifications are primarily due to structural rearrangements induced by the energetic ions. Specific chemical doping contribution to conductivity is noted for halogen implantation in PAN435. The temperature dependence of conductivity of PAN heat treated at 750°C suggests a two path conduction, namely a three dimensional variable range hopping conduction and a metallic conduction. After ion implantation, the conductivity-temperature dependence is interpreted in terms of a variable range hopping conduction mechanism.

sjodeh's picture

Chemical Structural Characterization of Pyrolyzed and Subsequently Ion-Implanted Poly(Acrylonitrile)

Journal Title, Volume, Page: 
Journal of Analytical and Applied Pyrolysis- J. Anal. Appl. Pyrolysis 82 (2008) 235–239
Year of Publication: 
2008
Authors: 
Shehdeh Jodeh
Department of Chemistry, Najah National University, P.O. Box 7, Nablus, Palestine
Current Affiliation: 
Department of Chemistry, An-Najah National University, P.O. Box 7, Nablus, Palestine
Preferred Abstract (Original): 

Infrared (IR), Auger electron spectroscopy (AES) and X-ray photoelectron spectra (XPS) of pristine, pyrolyzed, and ion-implanted poly(acrylonitrite) (PAN) samples were obtained in order to correlate the structural changes accompanying pyrolysis and implantation with the electrical properties of the respective PAN products. The results show that PAN is first converted to a polyconjugated heterocyclic ladder structure at a temperature of 435 °C and then to a graphite-like structure at temperature above 750 °C. Pyrolysis studies took place in a temperature range of 350–750 °C. IR studies showed that upon heat treatment at 435 °C, major structural changes occur as indicated by the complete disappearance of the nitrile and methylene absorption bands and the formation of new bands. The degree of conjugation in pyrolyzed PAN can be selectively controlled by the proper choice of the heat treatment temperature. From the studies, ion implantation causes extensive nitrogen depletion and the nitrogen chemical state in the implanted sample is different from that found in the pyrolyzed materials. Upon ion implantation, the component assigned to the nitrogen in a sigma bonding state (401.27 eV) increased in intensity (46%) relative to the intensity (27%) of the component for which nitrogen is in a hetroaromatic structure. Both AES and XPS analysis showed the variation of C:N ratio as a function of heat treatment.

Syndicate content