The effect of testing conditions on the time of establishing a steady-state activity of the catalysts for the second hydrocracking step

Abstract

Catalysts for the second hydrocracking step were tested under different conditions in order to reduce the time of establishing their steadystate activity. The tests were carried out at a laboratory bench under the conditions close to industrial operation and typical of the second hydrocracking step. The introduction of an additional step at the onset of testing with the increased temperature and feed space velocity as well as the use of a dimethyl disulfide solution in decane as a sulfurization mixture were shown to considerably reduce the duration of experiment. Conditions of the preliminary step were selected so as to preserve the catalyst selectivity toward the diesel fraction.