RESIDUUM HYDROTREATING/APPLICATION OF LIQUID- SOLID CHROMATOGRAPHY FOR THE STUDY OF HYDROTREATED PRODUCTS.

Iraqi reduced crude (above 350/sup 0/C) was hydrotreated in a fixed-bed reactor with commercial Ni-Mo-alumina catalyst. Reaction temperature varied from 320 to 400/sup 0/C over liquid hourly space velocity ranging from 0.82 to 2.6 h/sup -1/. Hydrogen pressure was kept constant throughout all the experiments at 6.1 MPa with hydrogen/oil ratio about 300 NL/L. Asphaltenes were precipitated from the reduced crude and hydrotreated products with 15 parts of n-pentane (by volume) to 1 part of sample. Then, the deasphaltened products were fractionated by liquid- solid chromatography for saturates, aromatics and polar- aromatics separation. The kinetic study of aromatics and polar- aromatics hydrogenation indicates that these reactions are well correlated with a second-order kinetics. The rate constants of aromatics and polar-aromatics hydrogenation were calculated. Finally, the apparent activation energy (Ea), enthalpy of activation (..delta..H) and entropy (..delta..S) were calculated for hydrogenation of aromatics and polar-aromatics of reduced crude during hydrotreating.