Catalytic cracking of Arabian Light VGO over novel zeolites as FCC catalyst additives for maximizing propylene yield

Mathematical modelling of catalytic cracking riser reactor

“…The operating efficiency of catalytic cracking units is determined by a broad range of operation indicators of non-stationary conjugate "riser-regenerator" system [1][2][3][4]. The quality and the yield of the light fractions in the catalytic cracking depend on the feedstock composition, the process conditions of the reactor and regenerator unit, the type and activity of the catalyst circulated continuously between the reactor and regenerator, etc.…”

Maximization of propylene in an industrial FCC unit

“…(28)- (53) [2,19]. Equations (28) and (29) describe the catalyst and gas velocity profiles across the riser [2]. Equations (30) and (31) describe the gas volume fraction, ɛ g , and catalyst volume fraction, ɛ c ; they provide a hydrodynamic constrain such that the summation of the volume fractions is unity.…”

“…Where propylene is required as a separate lump, this eightlumped model may not be useful. Some kinetic models for the propylene production are based on catalytic cracking, such as the four-lumped model which includes propylene as a component of a gas lump [29]; the ten-lumped model with propylene as a distinct lump [30] and six-lumped model with distinct propylene lump [15]. To maximize the yield of propylene in a lumped kinetic model, propylene has to be a separate lump.…”

“…To maximize the yield of propylene in a lumped kinetic model, propylene has to be a separate lump. The gas lump in Hussain et al [29] is a mixture of propylene, butylene and some dry gas; hence, it is unsuitable for use to maximize propylene because maximizing gas lump would mean maximizing other gases along.…”

“…The boundaries for the mass flow rates of gas oil and catalyst are chosen such that it reflects the typical industrial FCC unit limits for C/O ratios of 4:1-10:1 by weight [48], Sadeghbeigi [49], [9]. C/O ratios for propylene production in high severity units and riser-downer are higher [18] than the C/O ratios used in conventional FCC units, which vary between 1 and 6 [16,29,50] (68)…”