Both Ru,(CO),, and [H,Ru,(CO),,] react rapidly with cyclopentadiene in the absence of oxygen to yield [RuH(CO),(q-C,H,)],(11; M = Ru), quantitatively, characterised in part via high-yield conversion into [RuH(CO)(PPh,) (q-C5H5)]. In the presence of oxygen [{Ru(CO),(q-C5H5)},], (111; M = Ru), is obtained in ca. 70% yield. The complex [Ru(CO),(q-C,H,)],( I ; M = Ru), has been isolated and shown to be a direct precursor of (11). Treatment of ( I ; M = Ru) with [Ph,C] [BF,] gives [Ru(CO),(q-C5H5)] [BF,], while triphenylphosphine displaces C5H6 forming [Ru(CO),(PPh,),]. Carbonylation (1 00 atm) of [RuH(CO) (PPh,) (q-C5H5)] in the presence of Et,O.BF, gives [Ru(CO),(PPh,) (-q-C5H5)] [BF,] in high yield. A minor product of the reaction of Ru,(CO),, and C5H6 is tentatively identified as [ R U , H ( C O ) ~( ~~-C ~H ~) ] , (IV) ; a related fluxional osmium complex, [Os,H,(CO),(q2-C5H4)],is obtained on treating [H20s3(CO),,] with C5H6. Low-yield formation of ( I ; M = 0 s ) and (11; M = 0 s ) from reaction of Os,(CO),,, [H,Os,(CO),,],or [H,Os(CO),] with C5H6 is described.IT has been suggested 1,2 that the reaction of iron pentacarbonyl with cyclopentadiene proceeds to the observed product [{Fe(CO),(q-C,H,)},], (111; M = Fe),, via intermediate ?-C,H, and q-C,H, iron complexes, as shown in the Scheme. This is now generally accepted, following the subsequent isolation of [Fe(CO),(q-C,H,)], ( I ; M =

This paper demonstrates the important roles of feedstock and catalyst in determining the yield structure during fluid catalytic cracking (FCC) of bitumen-derived vacuum gas oils (VGOs). Three nonconventional VGOs, derived from Canadian oil-sands bitumen, were catalytically cracked in a fluid-bed microactivity test (MAT) reactor. Two commercial equilibrium catalysts were used:  a bottoms-cracking catalyst containing rare earth exchanged Y zeolite (REY), and an octane-barrel catalyst containing rare earth ultrastable Y zeolite (REUSY) mixed with a small amount of ZSM-5. Both catalysts were embedded in active matrixes. Results indicated that the REY catalyst was more active, producing higher yields of valuable distillates and less coke for the same feed, whereas the catalyst containing REUSY/ZSM-5 gave more light gases and less gasoline (although the quality of this gasoline might be better). These results could be related to catalyst properties including zeolite type, rare earth content, matrix pore structure, zeolite-to-matrix ratio, and surface characteristics. The three feeds were ranked based on their yield structures, which could be explained through feed analyses, precursor concentrations determined by GC-MS, and product characterization data from a PIONA analyzer. MAT results were compared with riser pilot plant data at 55 and 65 wt % conversion. In general, at the same conversion, the difference in a given product yield from the two units could be maintained within 15%. Coke yield showed a greater disagreement, however, due to methodological differences in the analysis.

This study was conducted in an effort to learn more about the roles of feedstock and catalyst in the distributions of sulfur and nitrogen in liquid products after catalytic cracking. A hydrotreated coker gas oil, a hydrotreated deasphalted oil, a virgin gas oil, all derived from Canadian oil-sands bitumen, were catalytically cracked in a fluid bed microactivity test (MAT) unit with two commercial catalysts. These were the equilibrium catalysts, bottoms-cracking and octane-barrel catalysts, respectively, both containing active matrixes. The cracked liquid products were analyzed for sulfur and nitrogen distributions with boiling point, from which the sulfur and nitrogen contents of gasoline, light cycle oil (LCO), and heavy cycle oil (HCO) fractions were determined. Variations of concentrations in each product cut with conversion were discussed, along with the hydrogen transfer indices of catalysts and the hydrogen yields of feeds. The overall distribution of feed sulfur in cracked products, and the relationship of the sulfur content of feed with that of LCO, confirmed the findings reported in the literature. The same three feeds were also cracked with the octane-barrel catalyst in a riser pilot plant. The sulfur and nitrogen concentrations in each product fraction from MAT were found to be in reasonably good agreement with those obtained from the riser pilot plant operation. Results from this study will provide the scientific community with a better understanding about the cracking chemistry of sulfur- and nitrogen-containing species in gas oils under different test environments.

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