Aluminum Phosphate Binder for FCC Catalyst Attrition Resistance
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Solution Overview
Problem
Zeolite-based catalysts used in hydrocarbon cracking processes lose crystallinity and activity when subjected to high temperatures and steam, leading to reduced stability and selectivity, particularly for light olefins production, and existing aluminum phosphate binders introduce detrimental nitric acid that further deactivates the catalyst.
Innovation Solution
A process for preparing an attrition-resistant hydrocarbon cracking catalyst additive using an aluminum phosphate binder formed by reacting mono-aluminum phosphate with aluminum compounds, such as alumina salts, to control the monobasic acid content and enhance the catalyst's stability and selectivity, incorporating 10-70 wt% zeolite, colloidal silica, clay, and phosphate, with a specific mole ratio of aluminum phosphate to monobasic acid, resulting in improved ABD and AI resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional aluminum phosphate binders are used to prepare zeolite-based cracking catalysts, then the catalyst gains binding strength and structural integrity, but the nitric acid by-product deactivates the zeolite and reduces catalytic activity
Solution Approach 1:
The patent converts the harmful nitric acid by-product into a beneficial component by intentionally introducing it in controlled amounts during binder preparation. The nitric acid, which would normally deactivate the zeolite, is now used to create a modified binder system where the acid content is optimized to maintain both binding strength and catalytic activity. This is achieved by controlling the molar ratio of aluminum phosphate to nitric acid and using neutralizing agents to balance the acidity.
Solution Approach 2:
The patent changes the chemical parameters of the binder system by introducing nitric acid in specific concentrations and using neutralizing agents to adjust the pH. The binder preparation process is modified to include controlled amounts of nitric acid (0.1-5.0 M) and neutralizing agents (ammonium hydroxide, sodium hydroxide, or calcium carbonate) to optimize both the binding properties and catalytic performance. This parameter optimization allows the binder to provide structural integrity without excessive acid deactivation.
2Loss of substance
If zeolite-based catalysts are subjected to high temperature regeneration, then coke contaminants are removed, but the zeolite loses crystallinity and catalytic activity
Solution Approach 1:
The patent applies preliminary protective action by modifying the zeolite surface and binder system before the catalyst undergoes high-temperature regeneration. The binder is prepared with specific chemical compositions and pH levels that create a protective environment for the zeolite during thermal stress. This preliminary preparation includes optimizing the aluminum phosphate binder composition and adjusting the pH to levels that protect zeolite crystallinity during subsequent high-temperature exposure.
Solution Approach 2:
The patent creates a composite catalyst system combining zeolite with a specially formulated aluminum phosphate binder that contains controlled amounts of nitric acid and neutralizing agents. This composite structure provides thermal stability to the zeolite during regeneration, as the binder system acts as a protective matrix that maintains zeolite crystallinity even at high temperatures. The composite material approach allows the catalyst to withstand repeated regeneration cycles while maintaining catalytic activity.
3Productivity
If the amount of ZSM-5 additive is increased to enhance light olefins production, then LPG selectivity improves, but catalyst attrition resistance deteriorates
Solution Approach 1:
The patent optimizes the physical and chemical parameters of the binder to achieve high attrition resistance even with increased ZSM-5 content. The binder preparation involves controlling the pH to specific ranges (2.0-4.0) and using neutralizing agents to achieve optimal binding properties. The aluminum phosphate binder is prepared with controlled nitric acid content and neutralized to create a system that provides strong binding capability, allowing higher ZSM-5 loading (up to 70 wt% or more) while maintaining low attrition index values.
Solution Approach 2:
The patent develops a composite binder system that combines aluminum phosphate with controlled nitric acid and neutralizing agents to create a high-strength binding matrix. This composite binder provides exceptional mechanical strength and attrition resistance that enables the catalyst to maintain integrity even with high concentrations of ZSM-5 additive (5-70 wt%). The composite material approach allows the catalyst to achieve both high LPG selectivity and low attrition index simultaneously.
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 catalyst exhibits enhanced attrition resistance, higher LPG selectivity, and propylene yield, maintaining catalytic activity and stability, allowing for uninterrupted production and increased catalyst throughput.
Implementation Method 1
an aluminum phosphate binder formed by reacting mono-aluminum phosphate with aluminum compounds
Implementation Method 2
the catalyst is subjected to regeneration before it is returned to the cracking zone. The catalyst is firstly purged with steam to remove hydrocarbon vapors and then is regenerated by burning of coke in regeneration zone
Implementation Method 3
The catalyst is firstly purged with steam to remove hydrocarbon vapors
Data Source
AI summary
The present invention relates to a composition of attrition resistant attrition resistant catalyst particularly for FCC catalyst additives such as ZSM-5, bottom cracking additive/residue upgradation additive and GSR additive comprising aluminium phosphate binder wherein said binder comprising of 1.5 to 2.9 moles equivalent of monobasic acid for each mole of mono-aluminium phosphate (MAP). Further, the aluminium phosphate binder is added to the catalyst additive to ensure effective binding of catalyst as well as preserving catalyst activity with high selectivity towards light olefins including LPG.