Study of Hydrodesulfurization by the Use of 35S-Labeled Dibenzothiophene. 2. Behavior of Sulfur in HDS, HDO, and HDN on Sulfided Mo/Al2O3 Catalyst

Article abstract of DOI:10.1021/j100054a028

To investigate the behavior of sulfur during the hydrodesulfurization (HDS), 35S-labeled dibenzothiophene (<35S>DBT) was reacted on sulfided Mo/Al2O3.It was found that 35S in <35S>DBT was accommodated on the catalyst and the concentration of 35S on the catalyst always reached a steady state under fixed reaction conditions. 35S accommodated on the catalyst cannot be removed without the incorporation of sulfur from HDS of sulfur compounds such as DBT, benzothiophene, thiophene, and thiophenol.The removal rate of 35S from the catelyst depended upon the rate of HDS of these compounds, that is, the amount of sulfur incorporated into the catalyst.It was suggested that H2S is formed from some portion of sulfur on the surface of the catalyst othe than from that in the sulfur compounds.When hydrodenitrogenation (HDN) and hydrodeoxygenation (HDO) reactions were carried out on the catalyst containing 35S, some portion of 35S could be replaced by oxygen atoms and released as <35S>H2S; in contrast to this, 35S was hardly replaced by N atoms.