The catalytic cracking behavior of compound types in the >650°F resid from a Wilmington, CA, 14.2°API crude was investigated. Liquid Chromatography (LC) was used to sepm'ate the resid into eight fractions. These fractions were used as feedstocks for a bench scale fluidized catalytic cracking (FCC) unit. Gasoline was produced almost exclusively from neutral (65 % of whole resid) components. Acidic and basic types were partially converted to coke plus small amounts of C! and C2 gases, with the balance primarily carrying over as heavy liquid products. Gasoline composition depended on the type and quantity of polar compounds present in the feed because both acidic and basic compounds inhibited cracking reactions (13-scission, hydrogen transfer, etc.) to varying degrees. In accordance with prior work, basic nitrogen compounds exhibited the largest inhibitory effect on cracking. Their effect is dependent on concentrations up to a limiting value which may correspond to saturation of susceptible catalyst sites. On an equal weight basis, the effect of high boiling (high molecular weight) bases was less than those occurring in the 650-1000°F distillate range. Pm'titioning of nitrogen present in acidic (e.g. carbazole) forms in the feed into liquid products was greater than for basic nitrogen. Thiophenic forms of sulfur partitioned more into liquid and less into gaseous (H2S) products than sulfide-type sulfur. Coke yield was approximately proportional to microcarbon residue test results for all feeds. Ongoing work with additional feedstocks has indicated behavior similar to that of Wilmington. Selected Wilmington liquid products are undergoing detailed analysis in order to determine relationships between feed versus product composition, particularly with respect to acidic and basic types.

The fluid catalytic cracking (FCC) behavior of compound types present in the >650 °F resid from Brass River (Nigerian) crude was investigated. Liquid chromatography and distillation were employed for separation of selected compound type fractions from the resid; the resulting fractions were then cracked using a bench scale FCC unit. The FCC behavior for each compound type was defined in terms of the resulting product distribution (yields of gas, gasoline, etc.) sulfur and nitrogen partitioning, and in selected cases, gasoline composition. Results obtained from Brass River fractions were compared to those obtained from an earlier FCC study of compound types from Wilmington, CA, >650 °F resid. Correlations were derived for gasoline and coke yields from feedstocks derived from either crude. Brass River is a sweet, paraffinic crude which gives rise to a >650 °F resid with very favorable FCC characteristics. Although the bulk of the FCC gasoline was produced from cracking hydrocarbon types present, significant gasoline production also occurred from heteroatomic compounds (acids/bases) in Brass River. Conversely, negligible gasoline production was observed previously from cracking Wilmington acid/base types. However, feedstocks from both crudes exhibited greater conversion of sulfide sulfur to H2S compared to thiophenic forms of sulfur, and greater carryover of acidic forms of nitrogen (e.g., carbazole) compared to basic forms (e.g., quinoline). Overall gasoline composition depended on hydrocarbon type composition of feedstocks but was also influenced by presence of acids and/or bases in the feed. On the other hand, the detailed distribution of isomers within a given gasoline homolog, e.g., C3-benzenes or C9 isoparaffins, was nearly independent of feed composition. Results obtained for Brass River will serve as benchmarks for future FCC data obtained from low-quality feedstocks.

The fluid catalytic cracking (FCC) behavior of compound types present in the >650°F resid from Maya 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 using a bench-scale FCC unit. The FCC behavior for each compound type was defined in terms of the resulting product distribution (yields of gas, gasoline, etc.); sulfur, nitrogen, nickel, and vanadium partitioning; and, in selected cases, gasoline composition. Results obtained from Maya fractions were compared to those obtained from earlier FCC studies of compound types from Wilmington, CA, and Brass River, Nigeria, >650°F resids. A conceptual model was proposed that adequately predicted FCC product slates obtained from >650°F neutral fractions from Maya and the other crudes. An important premise of the model was primary production of gasoline and C 3 /C 4 gases from alkyl side chains and acyclic paraffins in feeds with concurrent conversion of aromatic and naphthenic cores to cycle oils. The product slates calculated from the model agreed well with those determined experimentally. Highly aromatic feedstock constituents presumably formed only coke and light gases. A calculation of hydrogen transfer resulting from cracking indicated no significant hydrogen exchange between aliphatic gasoline or C 3 /C 4 gas precursors and naphthenic/aromatic cores. Implications of the model toward improving FCC feed pretreatment and performance evaluation are discussed.

The fluid catalytic cracking (FCC) behavior of compound types present in the >650°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 using a bench-scale FCC unit. The FCC behavior for each compound type was defined in terms of the resulting product distribution (yields of gas, gasoline, etc.); sulfur, nitrogen, nickel, and vanadium partitioning; and in selected 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°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 ratio of hydrogen divided by carbon plus sulfur (H/(C + S)), the fraction of the feed volatilized at the cracking temperature f c T, effective metal content (M eff ) Ni + V/4) expressed in µequiv/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 experimental gasoline yields typically agreed within 1.5 wt %, which is the pooled standard deviation for the experimental data. An infrared spectrophotometric method is provided for determination of N Am ; the other parameters are measured using standard methods or previously published procedures.

The fluid catalytic cracking (FCC) behavior of compound types present in the >650 °F resid from Merey crude was investigated. Distillation and liquid chromatography were used to separate selected compound-type fractions from the resid; the resulting fractions were then cracked using a benchscale FCC unit. The FCC behavior for each compound type was defined in terms of the resulting product distribution (yields of gas, gasoline, etc.); sulfur, nitrogen, nickel, and vanadium partitioning; and, in selected cases, gasoline composition. Results obtained from the Merey fractions were compared to those obtained from earlier FCC studies of compound types from Lagomedio (Venezuelan), Wilmington (Californian), Maya (Mexican), and Brass River (Nigerian) >650 °F resids. Correlations using the five sets of data were developed for light gas, light cycle oil, and heavy cycle oil, as a function of five feed parameters (metals, microcarbon residue, sulfur, basic nitrogen, and hydrogen contents). The correlations are consistent with the data and have a standard error of 2 wt %.