Zeolite Catalysts

Zeolite Catalysts azs2 Wed, 05/07/2014 - 14:05

One of the significant developments in FCC practice was the introduction of zeolite catalysts in 1965. Catalysts and additives play a major role in the selectivity and flexibility of FCC processes. FCC catalyst consists of a fine powder with an average particle size of 60–75 μm and a size distribution ranging from 20 to 120 μm. Four major components make up the catalysts: zeolite, active matrix, filler, and binder. Each of these constituents has a unique role to play, but zeolite is the key component that is more active and selective for high-octane number gasoline production [4]. Table 7.4 compares the octane numbers of some refinery products and FCC gasoline.

Components of FCC catalyst: binder, clay, pores, pseudocrystalline matrix systems, zeolite (60-70um)

Figure 7.9. Components of FCC catalyst [4].

Credit: Dr. Semih Eser © Penn State is licensed under CC BY-NC-SA 4.0

Table 7.4: Gasoline Octane Number
Product	RON (600 rpm)	MON (900 rpm)
Regular - Premium Gasoline	90-100	80-90
Straight Run Gasoline	60-68	60-68
FCC Gasoline (light)	93	82
FCC Gasoline (heavy)	95	85

Exercise 8

Exercise 8 azs2 Wed, 05/07/2014 - 14:08

Solve a problem on the material balance for the regenerator in Fluid Catalytic Cracking Process.

Material Balance for FCC Regenerator Problem

Burning the coke deposited on the catalyst particles generates all the heat necessary for catalytic cracking. Therefore, the coke burning rate is a critical parameter to control the rate of cracking. The composition of dry flue gas from the regenerator of an FCC unit is given in vol% as follows:

N₂: 81.6

CO₂:15.7

CO: 1.5

O₂: 1.2

The dry air flow rate to the regenerator is given as 593 SCMM (standard cubic meters per minute). Considering that a significant portion of coke is carbon, calculate the carbon burning rate in the regenerator in kg/min. Remember: 1 kgmole at STP = 22.4 m³)