Systematic Approach for Describing the HDS Phenomenon

Past reviews have described in detail the chemistry and mechanisms involved in the hydrodesulfurization of the most reactive organic species found in petroleum fuels (1-5). A vast amount of knowledge has been 

For highly substituted dibenzothiophenes, ring hydrogenation prior to sulfur extrusion is the major route to hydrocarbon production as, relative to the parent molecules, aliphatic substituents on aromatic ring carbons 

For proper kinetic evaluation of the conversion selectivity in such a case, it is necessary to find means for distinguishing the relative contributions of the various pathways to the formation of products. A systematic method for distinguishing parallel and sequential formation of products will be described, and results of HDS of such multiaromatic sulfur compounds will be discussed in these terms. For ease of understanding the following discussion, we define the various rate constants as follows. 

Rate constants such as kD represent rate constants involving sulfur removal from molecules, and rate constants such as kw and km represent rate constants involving hydrogenation of an aromatic ring. The subscripts 0, 1, and 2 indicate that, for the desulfurization process, the product is a 

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