New Gas-Phase Catalytic Oxidative Processes for Desulfurization of Diesel Fuel

Abstract

<p>An effective gas-phase oxidative desulfurization (ODS) process was proposed. The process was studied in a laboratory reactor with a proprietary catalyst at 300-400 ºС and ambient pressure with model fuels represented by thiophene, dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) dissolved in octane, isooctane or toluene. The reactivity of different sulfur containing molecules in ODS was shown to increase in the sequence: thiophene < DBT < DMDBT. The main sulfur containing product of oxidation of these compounds was SO<sub>2</sub>. During the gas-phase ODS both processes of sulfur species oxidation and processes of their adsorption were observed and studied. Based on the conducted studies, different ODS process designs comprising its integration with adsorption and regeneration processes and with conventional hydrodesulfurization (HDS) process were proposed. One scheme is based on alternating regimes of ODS and catalyst regeneration in two reactors: sulfur is removed from organic feedstock by oxidation and adsorption in one reactor while simultaneous regeneration of the catalyst that has accumulated sulfur compounds takes place in another reactor. Two other schemes are based on joint use of ODS and HDS. The conventional HDS process is most effective for removal of low-boiling sulfur containing compounds reactive with respect to hydrogen, while removal of refractory sulfur compounds, such as DMDBT is more easily achieved by gas phase ODS. Thus the combination of these processes is expected to be most efficient for deep desulfurization of diesel fuel.</p>

Preparation of Carbon Nanotubes with Supported Metal Oxide Nanoparticles: Effect of Metal Precursor on Thermal Decomposition Behavior of the Materials

“…These properties of CNMs, as well as adsorption capacity, the absence of strong acid sites and ability to activate oxygen have drawn attention to their use in the process of selective oxidation of sulfur-containing compounds in fuels [17][18][19][20][21][22][23]. In contrast to oxide supports for which different compositions of active components were studied and favorable compositions were selected [24][25][26][27] the open literature on supported active species on CNMs for oxidative desulfurization is quite limited and their optimal type, content and dispersion is not fully understood so far.…”

Environmental and Economic Efficiency of Comprehensive Technology of Sulfur Oxides, Nitrogen Oxides and Mercury Removal from Flue Gases

“…The analysis of scientific, technical and patent literature has shown that in order to reduce the content of sulfur and nitrogen oxides in the flue gases from the combustion of coal fuels three main technological methods are used [6,7,8,9,10,11,12,13]:  Reduction of the concentration of sulfur in the original coal coming to power and steam stations;  Reduction of the concentration of sulfur oxides formed during combustion of coal fuel containing sulfur by introducing Sulphur Capture Agents (SCA) in the combustion zone;  Reduction of the concentration of sulfur and nitrogen oxides in flue gases by means of purification of the latter using a number of known methods, most effective of which are methods of sorption and catalytic purification of flue gases.…”

The Development of Metal-Carbon Catalysts for Oxidative Desulfurization of Diesel Fractions

“…Economical advisability of this method decreases with stiffening of environmental requirements to the fuel quality, which makes it necessary to develop new approaches to the purification of hydrocarbon feedstock. Oxidative desulfurization (ODS) is among promising alternative methods for the removal of sulfur compounds and has considerable advantages over hydrodesulfurization [5][6][7][8][9][10][11][12][13][14][15]. The ODS process can be performed at lower temperatures and pressures and does not require the use of hydrogen, which is an expensive reagent.…”