Gas oil conversion

Coke-Conversion Kinetics. Coke formation kinetics and gas oil conversion are represented by the following irreversible reactions (cracking and coking) ... 

Blanding (10) first proposed the second order cracking kinetics for FCC. Krambeck (11) theoretically demonstrated that conversion in systems with a large number of parallel reactions can be approximated by simple second order kinetics. More recently, Ho and Aris (12) have developed a further mathematical treatment of this concept. An inhibition term was incorporated into the second order cracking kinetics for gas oil conversion to account for competitive adsorption. The initial cracking rate is then given by ... 

Effect of Composition and Pretreatment on Coke and H2 Selectivity. We examined the effect of catalyst composition and pretreatment on the selectivity for coke and H2. Results (Figures 5 and 6) indicate higher yields of coke and H2 at constant conversion for SA-59 relative to catalysts with lower alumina content. Pretreatment conditions influenced coke, H2 yields indirectly by influencing surface area and gas oil conversion. Thus, coke and H2 selectivity was not influenced by pretreatment conditions. We conclude that coke and H2 selectivity does not correlate with the concentration of A1 species of a particular coordination (eg., tetrahedral). 

Figure 1. Cross section of typical gas oil conversion catalyst (a) aluminum, (b) silicon, (c) lanthanum. Continued on next page.

Pillared rectorites are expanded clay minerals with a surface area in the 150-220 mVg range, and thermal and hydrothermal stability similar to that of zeolites with the faujasite structure (1-4). After steaming at 760°C/5h (100% steam, 1 atm), these materials retain their pillared structure, and at microactivity test conditions (MAT) they are as active as commercial fluid cracking catalysts (FCC) for gas oil conversion... 

Figure 3 shows a comparison between experimental and predicted gasoline yields as a function of gas oil conversion in the range of 480-520°C for GO-2 feedstock. Conversion is defined as the sum of gasoline, LPG, dry gas and coke yields. The effect of the type of feedstock on gasoline yield at 500 C is shown in Figure 4. 

This paper describes the physicochemical properties of natural rectorite samples pillared with aluminum chlorhydroxide (ACH) solutions containing (Aljj) the [A1j2 4(0H)24(H20) 2 cation. Stability, acidity, cracking activity and product selectivities from gas oil conversion will be compared to those of similarly prepared pillared montmorilIonite catalysts. 

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