Dearomatization, cetane improvement and deep desulfurization of diesel feedstock in a single-stage reactor

Abstract

Hydrotreating of light cycle oil over CoMo/AI20.~, NiMo/AI~O3 and NiW/AI203 catalysts has shown that the type of catalyst has a critical influence on the composition and properties of the product. Divergent effects of aromatics content and molecular weight on the eetane index by these catalysts occurred. Data show that it was not possible to obtain a diesel product that meets stringent specifications using one type of catalyst in a single-stage reactor even under severe operating conditions.

Naphthalene Hydrogenation over Silica Supported Nickel Phosphide in the Absence and Presence of N-Containing Compounds

“…Conventional hydroprocessing technology is used to reduce aromatics in the fuels through the hydrodearomatization reaction. , Typical catalysts in aromatic hydrogenation are sulfides based on Mo or W and promoted with Ni or Co supported on alumina or Al 2 O 3 . ,− The drawbacks of these catalysts include severe operating conditions such as high temperature and high pressure. Furthermore, only moderate levels of saturation of aromatic content under typical hydrotreating conditions can be obtained due to equilibrium limitations. ,,, Supported noble metal catalysts showed high catalytic activity for aromatic hydrogenation at low temperature. However, the presence of sulfur strongly influences their catalytic activity due to the poisoning of active sites. ,, …”

Hydrogenation of tetralin on silica–alumina-supported Pt catalysts II. Influence of the support on catalytic activity

“…Currently, hydrogenation is one of the most important routes for reducing the concentration of aromatics, leading to fuel components with high cetane numbers. Conventional diesel hydrotreating based on sulfided NiMo, CoMo, and NiW/Al 2 O 3 catalysts is effective in decreasing the concentration of S-and N-compounds; however, insufficient reduction levels of aromatics in the diesel fraction are obtained unless severe operating conditions are applied (i.e., high temperature and hydrogen partial pressure, low space velocity) [2][3][4].…”

Solvent extraction of aromatic components from petroleum derived fuels: a perspective review

“…Typical conventional catalysts for fuel hydroprocessing are sulfided Co-Mo and Ni-Mo supported on alumina. Some studies 16,51,54 have recognized that dearomatization is more difficult than hydrodesulfurization under conditions that are normally used for hydrotreating due to the type and amount of aromatic species present in the diesel fuel as well as the complexity of the reactions. Moreover, it is not possible to obtain a diesel product that meets stringent specifications with respect to aromatics or achieves complete hydrogenation of aromatics by using conventional middle distillate hydrotreaters due to equilibrium limitations under typical hydrotreating conditions.…”