FLUIDIZED BED CATALYTIC CRACKING OF HYDROCARBON FEEDSTOCK PARTICULARLY FEEDSTOCK HAVING HIGH CONTENT OF BASIC NITROGENCOMPOUND

摘要

A fluid catalytic cracking (FCC) process for the cracking of a hydrocarbon charge, partic. one contg. a high basic N content in a tubular reaction zone comprises: - a supply of catalyst particles (at least in part regenerated) to the upper part of the reaction zone; - introduction and dispersion of the charge to be treated in the upper part of the reactor (beneath the entry pt. of the catalyst); - co-current circulation in mutual contact in the reaction zone of the catalyst and charge to be treated; - sepn. at the lower part of the reaction zone, of the deactivated catalyst from the reaction prods.; - stripping of the deactivated catalyst; - regeneration of at least part of the stripped catalyst in a regeneration zone; - recycling of the regenerated catalyst to the upper reaction zone, and - transfer of the cracked prods. to a sepn. zone. The process has the following characteristics: the catalyst circulates from top to bottom co-currently with the charge in the tubular zone; a catalyst is used which in equilibrium state (150 degrees C and 5 mbars) adsorbs less than 250 mu moles (pref. 50 mu moles)/g of pyridine and retains after heating at 350 degrees C in a vacuum, no more than 20% (pref. 10%) of the amt. absorbed.