Reaction of nitrogen and sulphur compounds during catalytic hydrotreatmentof shale oil

Pyrolysis oil derived from oil shale was hydrotreated in a stirred reactor at 400 degreesC for a hydrotreatment time of 12 h. The influence of hydroge n pressure at 7, 9, 11 and 15 MPa and the role of catalyst type in the form of nickel-molybdenum and cobalt-molybdenum types was investigated in relat ion to the yield and composition of the products. The results showed that n itrogen and sulphur contents of the hydrotreated oils were significantly de creased after hydrotreatment and were further decreased with increasing pre ssure of hydrogen. Correspondingly, detailed analysis of the oils showed th at the aromatic nitrogen and sulphur containing compounds were decreased in concentration in the oils as the hydrogen pressure was increased. The comp arison of catalyst types showed that there was little difference in the den itrogenation and desulphurisation efficiency of the two catalysts. (C) 2001 Elsevier Science Ltd. All rights reserved.