Multi-Silica FCC Catalyst Composition for Attrition Resistance
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Solution Overview
Problem
Existing FCC catalysts face challenges in achieving a balance between high attrition resistance and effective accessibility of active sites, as well as sufficient physical strength, which are not adequately addressed by prior art methods using single silica sources.
Innovation Solution
A process involving a combination of two silica sources, namely sodium stabilized colloidal silica and ammonia stabilized colloidal silica, is used to create an FCC catalyst, with a specific composition and pH adjustment steps to enhance catalyst properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a conventional FCC catalyst is used, then initial run length is limited, but catalyst cost and regeneration frequency increase
Solution Approach 1:
The patent applies composite materials by combining multiple silica materials (amorphous silica and crystalline silica such as quartz, tridymite, or cristobalite) in the catalyst support structure. This composite approach creates a more durable support that resists degradation during regeneration cycles, thereby extending the initial run length and reducing regeneration frequency without sacrificing catalytic activity.
2Duration of action of stationary object
If catalyst durability is improved, then regeneration cycles are reduced, but catalyst complexity increases
Solution Approach 1:
The patent employs parameter changes by carefully controlling the silica-to-alumina ratio (specifically SDA ratios of 5:1 to 20:1), the crystallinity of the silica phase (5-50%), and the pore structure parameters. These parameter optimizations enhance catalyst durability and resistance to thermal degradation during regeneration, extending catalyst lifespan while maintaining a manageable structural complexity through systematic parameter control rather than introducing fundamentally new complex structures.
3Stability of the object's composition
If hydrothermal stability is enhanced, then catalyst activity is maintained longer, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-forming the multi-silica support structure with controlled crystallinity and pore characteristics before introducing the active catalyst components. The support is prepared with specific SDA ratios and silica phase compositions in advance, which then provides a stable foundation that maintains hydrothermal stability and catalytic activity over time, while simplifying the subsequent catalyst manufacturing process.
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 resulting catalyst exhibits improved attrition resistance and performance, particularly in reducing coke formation and enhancing bottoms upgrading, as demonstrated by laboratory tests.
Implementation Method 1
A fluid catalytic cracking (FCC) catalyst support comprising amorphous silica and crystalline silica
Implementation Method 2
The method comprises reacting a silica-alumina gel with an alkylalumoxane
Data Source
AI summary
Process for the preparation of a catalyst and a catalyst comprising more than one silica is provided herein. Thus, in one embodiment, the invention provides a particulate FCC catalyst comprising about 5 to about 60 wt% one or more zeolites, about 10 to about 45 wt% quasicrystalline boehmite (QCB), about 0 to about 35 wt% microcrystalline boehmite (MCB), greater than about 0 to about 15 wt% silica from sodium stabilized colloidal silica, greater than about 0 to about 30 wt% silica from ammonia stabilized or lower sodium colloidal silica, and the balance clay and the process for making the same. This process results in attrition resistant catalysts with good performance.