Riser pilot plant

Increasing Motor Octanes by Using ZSM—5 in Catalytic Cracking Riser Pilot Plant Gasoline Composition Analyses... 

In this paper we will discuss the detailed compositional analyses generated in riser pilot plant studies with and without ZSM-5. In particular, we note the relative yields of both the branched and normal paraffins and the iso and normal olefins as a function of carbon number and relate these to the increase in motor octane. Two different base catalysts were used in this study to provide a wide range in the base gasoline composition. 

These catalysts were evaluated in an isothermal, bench-scale, riser pilot plant at 1000 F average riser temperature, 5 seconds oil residence time (ORT) and at least four different catalyst to oil ratios varying from 4 to 10. The feedstock used was a Nigerian gas oil with properties as shown in Table III. Gases were analyzed by GC. The liquids were analyzed by a GC to give the carbon number isomer breakdown. In addition there was enough sample to analyze for mini-micro Motor octane which has a reported reproducibility of 0.75 octane for a single determination. 

The coke deactivation exponent n, is typically estimated from riser pilot plant experiments at varying catalyst contact time for different catalyst types. A value of n of 0.2 was found for REY catalyst data base. For USY and RE-USY catalysts n was estimated to be 0.4. 

Long-Residue Processing in a Riser Pilot Plant... 

A riser pilot plant has been successfully used to process heavy feedstocks with Conradson carbon contents as high as 10%w. 

A number of different types of laboratory scale units have been developed to simulate commercial catalytic crackers. These include fixed bed (MAT), fluidized bed, and riser units.(1,2,3) In particular, for simulating commercial riser FCC units which process residue, a riser pilot plant is the preferred choice. 

This paper describes experience with residue processing in catalytic cracking units in the industry, both on a commercial and pilot plant scale. Specific changes which have been made to the design and operating procedures of the Shell Canada Oakville Research Centre (ORC) riser pilot plant are also discussed. 

Shell Canada s Oakville Research Centre has had a riser pilot plant in operation for about ten years. A series of modifications have been made to the unit over the years in order to improve its ability to process heavier feedstocks. In spite of a rather low feedrate of 0.52 g/s (approximately 0.3 B/D), poorer quality feedstocks have been processed than those described above. To date, feedstocks with Conradson carbon contents up to 9.9%w and viscosities up to 120 cSt at 100 C have been successfully run in the ORC pilot plant. Operating experience with the pilot plant is summarized in Table I, and a schematic is shown in Figure 2. 

M. Schlossman et al, "Riser Pilot Plant for Catalytic Cracking Studies", Katalistiks 7th Annual FCC Symposium, Venice, Italy, May 12-13, 1986. 

Pappal, D. A., and Schipper, P. H. Increasing motor octanes by using ZSM-5 in catalytic cracking, Riser pilot plant gasoline composition analyses. ACS Symp. Ser., 452, Fluid Catal. Cracking, pp. 45-55 (1991). 

The selectivity improvements of the SAM-200 containing ULTIMA catalysts are especially pronounced when the catalyst is metallated to simulate the equilibrium catalyst conditions in a high metals environment arising from processing of heavy feeds in the FCC Unit. Table 5 summarizes Riser Pilot Plant (DCR) results of a competitive Resid Catalyst versus ULTIMA-445 after Cyclic Metals Impregnation of the catalysts to 5000 ppm Ni+V. 

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