Effect of Methyl Groups at 4- and 6-Positions on Adsorption of Dibenzothiophenes over CoMo and NiMo Sulfide Catalysts

Xiaoliang Ma, Jae Hyung Kim, Chunshan Song

Research output: Contribution to journalConference article

4 Scopus citations


The major sulfur compounds existing in the current commercial diesel fuels are alkyl dibenzothiophenes (DBT), especially those with one or two alkyl groups at the 4- and/or 6-positions, e.g., 4-methyldibenzothiophene (4-MDBT) and dimethyldibenzothiophene (4,6-DMDBT), which are difficult to remove by the conventional HDS processes. The adsorption of DBT, 4-MDBT, and 4,6-DMDBT on two sulfided commercial catalysts, i.e., Cr344 (CoMo/Al2O3) and Cr424 (NiMo/Al2O3), was studied using a liquid-phase adsorption device. By comparing DBT, 4-MDBT, and 4,6-DMDBT, the increases of adsorption selectivity in the order of 4,6-DMDBT < 4-MBBT < DBT indicated that the methyl groups at the 4- and 6-positions inhibited the interaction between the S atom in DBT and the active sites on the catalyst, which led to the decrease of adsorption capacities of 4,6-DMDBT and 4-MDBT on the catalyst. The adsorption capacities corresponding to the saturation point of 4,6-DMDBT, 4-MDBT, and DBT were ∼ 0.062, ∼ 0.064, and ∼ 0.068 mmole/g, respectively. At least one tenth of the adsorptive sites on the catalyst adsorbed DBT, but failed to adsorb 4,6-DMDBT due to the steric hindrance of the methyl groups at the 4- and 6-positions.

Original languageEnglish (US)
Pages (from-to)135-137
Number of pages3
JournalACS Division of Fuel Chemistry, Preprints
Issue number1
Publication statusPublished - Mar 1 2003
EventProceedings of the 2003 SPE/EPA/DOE Exploration Production Environmental Conference - San Antonio, TX, United States
Duration: Mar 10 2003Mar 12 2003


All Science Journal Classification (ASJC) codes

  • Energy(all)

Cite this