Fuel, Vol.77, No.1, 3-13, 1998
Medium severity hydrotreating and hydrocracking of Israeli shale oil - II. Testing of novel catalyst systems in a trickle bed reactor
Hydrotreating Israeli shale oil at 150 atm, an LHSV of 0.5-1.5 h(-1), a temperature of 340-400 degrees C, and a hydrogen to oil ratio of 1500 NL L-1 was studied in a trickle-bed reactor pilot plant packed with two novel catalysts in series. The first catalyst was Ni-Mo supported on wide-pore alumina and the second catalyst was Co-Mo-Cr supported an combined zeolite HY-alumina carrier. The desulfurization conversion was higher than 99% over the operating conditions tested while denitrogenation conversion varied over the range 74.3-99.9%. The pseudo-first-order denitrogenation rate constants measured at 380 degrees C increased from 1.9 to 2.9 h(-1) with increasing distillation temperatures of shale oil fractions from < 250 degrees C to > 380 degrees C. The apparent activation energy decreased from 29.8 to 23.1 kcal mol(-1). The effects of LHSV and temperature on the structure of shale oil components and hydrocarbons distribution was studied using H-1 and C-13 NMR and GC-MS methods. The yields of total liquid product, gasoline, jet and diesel fuels at 380 degrees C and LHSV = 0.5 h(-1) were 89.4, 9.3, 22.5 and 65.8 wt% of crude shale oil. The volume yield of liquid product per crude shale oil at those conditions was 106.9% It contained 160 ppm sulfur and 80 ppm nitrogen. The quality parameters of motor fuels produced from shale oil by hydrotreating with the two-catalyst system meets certain specifications except gasoline, which displayed low Reid vapor pressure and RON 72. A 400 h stability test at 380 degrees C indicated no catalysts deactivation.