The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This work investigates the feasibility of ultra-deep hydrodesulfurization (i.e. ⩽1ppm of sulfur content) of several diesel feedstocks, viz., regular (R), premium (P) and hydrotreated straight-run (HSR) at low pressures, i.e. 10bar, to lower significantly the operation costs. The premium and regular diesel contain additive packages with several components such as cetane boosters, antioxidants that...
The distribution of coke inside the pellets of several industrial spent hydroprocessing catalysts was analyzed using Raman spectroscopy. The shape of the coke profiles gives us information on the deactivation mechanism and the magnitude of diffusion limitations. Samples taken at the end of run showed the most pronounced coke profiles. Typical M-shaped profiles observed in a guard bed catalyst suggest...
Heavy oil residua contain large amounts of hetero-atoms, such as sulfur, nitrogen, oxygen and metals. The metals, mainly vanadium and nickel, are removed by catalytic hydrotreatment. Sulfur, nitrogen and oxygen containing compounds present in heavy oil residua can influence the rate at which the metals are removed, since they can adsorb competitively on the active site of the catalyst. Hence, the...
The oxidation of carbon black in the presence of catalytically active compounds has been studied under isothermal conditions in a flow reactor. In the presence of metal oxides, oxidation rates of the carbon black are found to be up to a few hundred times higher compared with the non-catalysed oxidation. Alkali metal carbonates increase this oxidation rate even up to a factor of over 100 000. The...
The kinetics of the uncatalysed oxidation of a flame soot and diesel soot were studied. Oxidation of the flame soot could be described by an nth-order model, with an order in carbon of 0.7. The order in molecular oxygen concentration was found to be 1 for the flame soot and slightly lower than 1 for the diesel soot. This order in oxygen concentration was also found to be a function of conversion...
X-ray photoelectron spectroscopy (XPS) was used to investigate the nitrogen functional forms present in several coals and their chars. The chars were prepared under different severity conditions to capture transformations in nitrogen functionality occurring during pyrolysis. It has been demonstrated that nitrogen present in coal in pyrrolic forms is converted into pyridinic functionalities upon...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.