FCC Catalyst Composition for Light Olefin Yield and Coke Reduction
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Solution Overview
Problem
Fluid catalytic cracking (FCC) units face challenges in maximizing light olefin production, particularly propylene, due to limitations in existing catalyst systems which require high severity operations, additional coke for heat balance, and inefficient light olefin selectivity, especially with hydrotreated VGO feeds.
Innovation Solution
A catalyst composition comprising 70-98% non-zeolitic material and 2-30% zeolite material, prepared by mixing, spray drying, and calcining, is used in a two-reactor FCC system, optimizing the catalyst-to-oil ratio, steam-to-hydrocarbon ratio, and residence time to enhance light olefin yields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high severity operation is used to increase light olefin yield, then propylene production increases, but additional coke is required to meet heat balance requirements
Solution Approach 1:
The patent changes the chemical composition parameters of the catalyst by incorporating specific zeolite materials (ZSM-5, ZSM-11, ZSM-22, SAPO-11) in optimized proportions within the catalyst structure. This compositional parameter change enables the catalyst to achieve high light olefin yields through modified reaction pathways that are more efficient in generating olefins while producing less coke, thereby resolving the contradiction between productivity and substance loss.
2Productivity
If ZSM-5 additive is used to increase light olefin yield, then propylene production increases, but gasoline yield decreases
Solution Approach 1:
The patent applies local quality by creating distinct functional zones within the catalyst structure. The catalyst contains specific zeolite components (ZSM-5, ZSM-11, ZSM-22, SAPO-11) distributed in optimized proportions that create localized active sites with different selectivity characteristics. This local differentiation allows the catalyst to selectively promote light olefin formation in specific regions while maintaining overall gasoline yield, resolving the contradiction between productivity and quantity of substance.
3Reliability
If conventional FCC catalyst is used, then catalyst activity is maintained, but light olefin selectivity is inefficient
Solution Approach 1:
The patent employs composite materials by combining multiple zeolite components (ZSM-5, ZSM-11, ZSM-22, SAPO-11) with matrix materials in a structured composite catalyst system. This composite structure integrates the benefits of different materials: the zeolite components provide high light olefin selectivity through their specific pore structures and acid sites, while the matrix material maintains catalyst activity and stability. The synergistic combination resolves the contradiction between reliability and manufacturing precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves increased yields of ethylene, propylene, and butylenes, with improved selectivity and reduced coke production, while maintaining catalyst activity under steam conditions, thus enhancing the overall efficiency of light olefin production in FCC units.
Implementation Method 1
a catalyst composition comprising: 70-98% of a non-zeolitic material; and 2-30% of at least one zeolite material
Implementation Method 2
spray drying, and calcining
Implementation Method 3
spray drying, and calcining
Data Source
AI summary
In accordance with the present subject matter there is provided a catalyst composition including 70-98% of a non-zeolitic material; and 2-30% of at least one zeolite material, the percentage being based on weight of the catalyst composition. The subject matter also relates to a method for preparation of the catalyst composition. The subject matter further relates to a process for the fluid catalytic cracking of a hydrocarbon feedstock.