Relating feedstock composition to product slate and composition in catalytic cracking. 5. Feedstocks derived from Lagomedio, a Venezuelan crude

The fluid catalytic cracking (FCC) behavior of compound types present in th e >650 degrees F resid from Lagomedio crude was investigated. Distillation and liquid chromatography were employed for separation of selected compound type fractions from the resid; the resulting fractions were then cracked u sing a bench-scale FCC unit. The FCC behavior for each compound type was de fined in terms of the resulting product distribution (yields of gas, gasoli ne, etc.); sulfur, nitrogen, nickel, and vanadium partitioning; and in sele cted cases, gasoline composition. Results obtained from Lagomedio fractions were compared to those obtained from earlier FCC studies of compound types from Wilmington, CA, Maya (Mexican), and Brass River (Nigerian) >650 degre es F resids, An equation is presented for prediction of gasoline yield for feedstocks derived from Lagomedio as well as other crudes. Gasoline yield ( wt % of feed) is calculated from these feedstock parameters: the atomic rat io of hydrogen divided by carbon plus sulfur (H/(C + S)), the fraction of t he feed volatilized at the cracking temperature f(c)T, effective metal cont ent (M-eff = Ni + V/4) expressed in mu equiv/g, basic nitrogen (N-B, wt %) and amide-type nitrogen (N-Am, wt %). The relation is G = 10.25[H/(C + S) log(f(c)T)] - 1.5M(eff) - 29(N-B + N-Am) + 30.2. Calculated and experiment al gasoline yields typically agreed within 1.5 wt %, which is the pooled st andard deviation for the experimental data. An infrared spectrophotometric method is provided for determination of N-Am; the other parameters are meas ured using standard methods or previously published procedures.