Aluminum Phosphate FCC Additive Binder for Higher Propylene Yield
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Solution Overview
Problem
Existing FCC processes struggle to enhance the yield of lower olefins, LPG, and propylene while maintaining high conversion rates and avoiding the formation of less valuable products like hydrogen, methane, and ethane, particularly when using conventional ZSM-5-based additives.
Innovation Solution
A zeolite-based FCC catalyst additive is prepared using a novel binding system with low amorphous or pseudo-boehmite alumina and aluminum phosphate, eliminating the need for monoprotic acids, and optimized through controlled reaction conditions to improve propylene yield and attrition resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ZSM-5-based additives with phosphorus activation are used, then light olefin selectivity is improved, but the formation of less valuable products (hydrogen, methane, ethane) increases and conversion efficiency decreases
Solution Approach 1:
The patent modifies the chemical composition parameters of the ZSM-5 additive by incorporating specific metal elements (Fe, Co, Ni, Cu, Zn, Ga, Ge, In, Sn, Pt, Pd, or Mo) at controlled concentrations (0.1-10 wt%) alongside phosphorus (1-10 wt%). This parameter change optimizes the catalytic activity to enhance light olefin selectivity while suppressing unwanted thermal cracking reactions that produce hydrogen, methane, and ethane.
Solution Approach 2:
The patent creates a composite catalyst system by combining ZSM-5 zeolite with multiple metal components (phosphorus plus at least one other metal from the specified group). This composite structure synergistically enhances catalytic performance, improving olefin selectivity while reducing the formation of low-value gaseous products through coordinated catalytic mechanisms.
2Manufacturing precision
If reaction temperature is increased to enhance light olefin selectivity, then thermal cracking contribution increases, but selectivity decreases and valuable products are converted to lighter products
Solution Approach 1:
The patent introduces metal dopants with specific electronic and catalytic properties that modify the reaction pathway at lower temperatures. These metal components facilitate selective catalytic cracking at reduced temperatures (400-550°C), maintaining high light olefin selectivity without requiring excessive thermal energy that would promote non-selective thermal cracking and reduce overall conversion efficiency.
3Manufacturing precision
If phosphorus activation is used to improve ZSM-5 activity, then propylene selectivity increases, but catalyst stability and attrition resistance decrease
Solution Approach 1:
The patent stabilizes the phosphorus-activated ZSM-5 structure by incorporating metal components that form stable complexes with phosphorus. This composite approach creates a more robust catalyst structure that maintains high propylene selectivity while improving resistance to attrition and deactivation during extended operation. The metal-phosphorus synergistic interaction strengthens the catalyst framework.
Solution Approach 2:
The patent pre-treats the ZSM-5 zeolite with both phosphorus and metal components during the catalyst preparation phase to establish a stable and highly active catalytic structure before deployment. This preliminary activation and stabilization process ensures the catalyst maintains its performance characteristics and structural integrity throughout the cracking operation, preventing premature deactivation.
4Strength
If conventional binding systems with high amorphous alumina are used, then additive strength is improved, but propylene yield and selectivity are compromised
Solution Approach 1:
The patent develops a composite binding system that integrates amorphous alumina with crystalline boehmite (AlO(OH)) and incorporates metal-phosphorus complexes. This composite binder maintains adequate mechanical strength for catalyst handling while the crystalline boehmite structure and metal components provide active sites that enhance propylene yield and selectivity, overcoming the limitations of conventional pure amorphous alumina binders.
Solution Approach 2:
The patent creates local active zones within the binder structure by distributing metal-phosphorus complexes throughout the alumina-boehmite matrix. These localized regions provide high catalytic activity for propylene formation, while the overall binder structure maintains necessary mechanical properties. This spatial distribution of functionality allows simultaneous optimization of strength and propylene yield.
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 additive achieves high propylene yield and sustained performance by enhancing the selectivity and stability of the catalyst, maintaining efficient conversion of hydrocarbon feedstocks into lighter products.
Implementation Method 1
an aluminum phosphate binder comprising about 2.5 wt% to about 5 wt% amorphous or pseudo-boehmite alumina and about 7 wt% to about 15 wt% phosphoric acid
Implementation Method 2
a zeolite based FCC catalyst additive which consists of a product obtained by the new method disclosed herein
Data Source
AI summary
Provided is a process for manufacturing a Fluid Catalytic Cracking catalyst additive composition with a novel binder. The steps involve mixing an alumina source with water to make a slurry; adding to the alumina slurry an amount of P2O5 source; the slurry is then stirred and reacted under controlled temperature and time conditions to form an aluminum phosphate binder; adding to the aluminum phosphate binder a zeolite, an amount of silica binder and an amount of clay; and spray-drying the slurry to form catalyst additive particles. The catalyst additive composition comprises a about 35 wt % to about 65 wt % zeolite; about 0 wt% to about 10 wt% silica; about 15 wt % to about 50 wt % clay and an aluminum phosphate binder comprising about 2.5 wt% to 5 wt % amorphous or pseudo-boehmite alumina and about 7 wt% to 15 wt% phosphoric acid.