Fluid catalytic cracking experimental

They began reduced crude cracking experimentation in a small 12,000 barrel per day (B/D) Fluid Catalytic Cracking (FCC) operating unit at Louisville, Ky. The RCC process was born from these goals, concepts and a small operating unit. The development and attributes of this process have been described in a number of articles and patents (1-6). 

Several reactor types have been described [5, 7, 11, 12, 24-26]. They depend mainly on the type of reaction system that is investigated gas-solid (GS), liquid-solid (LS), gas-liquid-solid (GLS), liquid (L) and gas-liquid (GL) systems. The first three arc intended for solid or immobilized catalysts, whereas the last two refer to homogeneously catalyzed reactions. Unless unavoidable, the presence of two reaction phases (gas and liquid) should be avoided as far as possible for the case of data interpretation and experimentation. Premixing and saturation of the liquid phase with gas can be an alternative in this case. In homogenously catalyzed reactions continuous flow systems arc rarely encountered, since the catalyst also leaves the reactor with the product flow. So, fresh catalyst has to be fed in continuously, unless it has been immobilized somehow. One must be sure that in the analysis samples taken from the reactor contents or product stream that the catalyst docs not further affect the composition. Solid catalysts arc also to be fed continuously in rapidly deactivating systems, as in fluid catalytic cracking (FCC). 

We have in our files about 500 published papers that report studies or contain kinetic equations of deactivation of solid catalysts of which about 50 contain kinetic equations of deactivation of the catalysts for the FCC (fluid catalytic cracking) process. Thus, much could be said on the subject especially since each author in the field uses his own approach and experimental technique. In addition, the literature used is different from one author to another which, in turn, makes possible a lot of different bases and approaches. Thus, for the FCC process each author and oil company lend to use their own model and kinetics, making it difficult to arrive at new approaches and optimum parameters of deactivation, especially if one is already comfortable with an approach and its corresponding parameters. 

The first three samples in Table 4 are ECO cuts from the FCC (fluid catalytic cracking) process. They all have relatively low levels of olefins (between 2.0 and 4.5wt% determined by SPE). Conversion of the Bromine numbers to olefin content by using high (2.9) and low (1.8) ratio values produced results that were close to those experimentally found by the SPE... 

On a graph of h tanh h vs. h we read that h = 0.94, and Fig. 6 tells us that for this value of h the fraction of surface available is 78%. This is in good agreement with experimental data on catalytic cracking since it predicts that fluid bed and fixed bed performance should be substantially the same. In other words, the cracking reaction is slow enough to use 30 A. unit pores in J -inch pellets with about 80% efficiency. 

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