Process for cracking high-boiling hydrocarbons using high pore volume,

Abstract

A process for economically converting carbo-metallic oils to lighter products. The carbo-metallic oils contain 650.degree. F..sup.+ material, at least a portion of said 650.degree. F..sup.+ material containing components which will not boil before about 1025.degree. F., said 650.degree. F..sup.+ material further being characterized by a carbon residue on pyrolysis of at least about 1 and a Nickel Equivalents of heavy metals content of at least about 4 parts per million. This process comprises providing a cracking catalyst having an average pore volume of at least about 0.2 cc per gram and an average particle diameter in the range of about 20 microns to about 150 microns, flowing the carbo-metallic oil together with the cranking catalyst through a progressive flow type reactor having an elongated reaction chamber, which is at least in part vertical or inclined, for a predetermined vapor riser residence time in the range of about 0.5 to about 10 seconds, at a temperature of about 900.degree. to about 1400.degree. F., and under a pressure of about 10 to about 40 pounds per square inch absolute sufficient for causing a conversion per pass in the range of about 50% to about 90% while producing coke in amounts in the range of about 6 to about 14% by weight based on fresh feed, and laying down coke on the catalyst in amounts in the range of about 0.3 to about 3% by weight. At least a portion of the feed remains unvaporized and deposits as a liquid on the catalyst particles. The ratio by weight of catalyst to oil is sufficiently high so that the total pore volume of the catalyst is greater than the volume of feed which will not boil below about 1025.degree. F.