I.FLUID CATALYTIC CRACKING: www,wissenschaftler-avh.in
B.CATALYST/ADDITIVES:
Q-48:
Can Catalyst Matrix Properties Improve Octane and Cetane in FCC Operation?
A-48:
Catalyst Matrix Properties Can Improve FCC Octane & Cetane
Background
The matrix of a FCC catalyst serves both physical and catalytic functions. Physical functions include providing particle integrity and attrition resistance, acting as a heat transfer medium, and providing a porous structure to allow diffusion of hydrocarbons into and out of the catalyst microspheres. The matrix can also affect catalytic selectivity product qualities, and resistance to poisons.
The matrix tends to exert its strongest influence on overall catalytic properties for those reactions which directly involve large molecules.
Here reference is made at various times to matrix type, as it refers to the matrix surface areas of fresh catalysts. The following summary should be used to correlate matrix type with actual fresh catalyst matrix area measurements:
Increasing a catalyst's matrix surface area will have a positive effect in upgrading product quality. Gasoline octane increases of 0.5 to 1.5 RON have been commercially demonstrated and attributed directly to increasing matrix surface area. Similarly improvements in cetane index of 1.7 to 2.9 numbers have been gained in commercial units. Increasing matrix surface area within a given family of catalysts can have the drawback of some increase in coke and gas make. Therefore, the optimal situation for a refiner is to take
full advantage of matrix cracking up to the limits of his particular unit.
In a commercial operation at refinery B. simultaneous improvements in both the gasoline octane and light cycle oil cetane index were observed as illustrated in Figure 1. At this refinery a rare earth exchanged zeolite catalyst with moderate matrix surface area replaced one with a low matrix surface area. The selective cracking of high boiling range molecules and the reduced hydrogen transfer associated with matrix cracking resulted in a gasoline octane improvement of approximately two RON and a light cycle oil cetane index increase of almost three numbers. The changes in qualities were proportional to the increase in matrix surface area in the circulating inventory. This is a processing advantage since most operational changes that improve octane, such as increased conversion or increased feed aromaticity will have a negative effect on LCO quality and depress the cetane value.
Increases in octane observed in a number of commercial operations are summarized in Table 1. Additional commercial data illustrating improvements in the light cycle oil cetane index gained with increased matrix
Data from commercial operations have verified the result of this study. Improvements of up to a 40% reduction in bottoms yield have been commercially realized when changing from a low to high surface area catalyst.
B.CATALYST/ADDITIVES:
Q-48:
Can Catalyst Matrix Properties Improve Octane and Cetane in FCC Operation?
A-48:
Catalyst Matrix Properties Can Improve FCC Octane & Cetane
Background
The matrix of a FCC catalyst serves both physical and catalytic functions. Physical functions include providing particle integrity and attrition resistance, acting as a heat transfer medium, and providing a porous structure to allow diffusion of hydrocarbons into and out of the catalyst microspheres. The matrix can also affect catalytic selectivity product qualities, and resistance to poisons.
The matrix tends to exert its strongest influence on overall catalytic properties for those reactions which directly involve large molecules.
Here reference is made at various times to matrix type, as it refers to the matrix surface areas of fresh catalysts. The following summary should be used to correlate matrix type with actual fresh catalyst matrix area measurements:
Increasing a catalyst's matrix surface area will have a positive effect in upgrading product quality. Gasoline octane increases of 0.5 to 1.5 RON have been commercially demonstrated and attributed directly to increasing matrix surface area. Similarly improvements in cetane index of 1.7 to 2.9 numbers have been gained in commercial units. Increasing matrix surface area within a given family of catalysts can have the drawback of some increase in coke and gas make. Therefore, the optimal situation for a refiner is to take
full advantage of matrix cracking up to the limits of his particular unit.
In a commercial operation at refinery B. simultaneous improvements in both the gasoline octane and light cycle oil cetane index were observed as illustrated in Figure 1. At this refinery a rare earth exchanged zeolite catalyst with moderate matrix surface area replaced one with a low matrix surface area. The selective cracking of high boiling range molecules and the reduced hydrogen transfer associated with matrix cracking resulted in a gasoline octane improvement of approximately two RON and a light cycle oil cetane index increase of almost three numbers. The changes in qualities were proportional to the increase in matrix surface area in the circulating inventory. This is a processing advantage since most operational changes that improve octane, such as increased conversion or increased feed aromaticity will have a negative effect on LCO quality and depress the cetane value.
activity are summarized in Table 2.
Data from commercial operations have verified the result of this study. Improvements of up to a 40% reduction in bottoms yield have been commercially realized when changing from a low to high surface area catalyst.
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