Phosphorus-Modified Silica Composite Zeolite Catalyst
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Solution Overview
Problem
Catalysts used in propylene production, particularly those containing zeolite, suffer from dealumination in high-temperature steam environments and cause corrosion of stainless steel equipment, leading to reduced performance and operational issues.
Innovation Solution
A silica composite containing phosphorus, zeolite, and silica is developed, with a phosphorus content adjusted between 0.01% to 1.0% by mass, to prevent dealumination and minimize stainless steel corrosion, produced through a method involving drying, calcining, and contacting a phosphate solution with the zeolite to maintain its powdery state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If zeolite is used as a catalyst in high-temperature steam environment, then catalytic activity is improved, but dealumination occurs leading to reduced catalyst performance
Solution Approach 1:
Phosphorus is introduced as an intermediary substance that mediates between the zeolite and the high-temperature steam environment. The phosphorus forms a protective layer or interacts with the zeolite structure to prevent direct attack by steam on aluminum sites, thereby maintaining catalytic activity while preventing dealumination.
Solution Approach 2:
The invention changes the chemical composition parameter of the catalyst by adding phosphorus (0.01-1.0% by mass). This compositional modification alters the catalyst's resistance to dealumination while preserving its catalytic function, allowing operation in high-temperature steam environments without performance degradation.
2Reliability
If phosphate solution is added to increase phosphorus content, then dealumination is prevented, but stainless steel corrosion increases
Solution Approach 1:
The invention optimizes the phosphorus content parameter within a specific range (0.01-1.0% by mass). This parameter optimization achieves sufficient protection against dealumination while limiting the formation of highly corrosive phosphoric acid, thereby balancing catalyst stability with equipment corrosion resistance.
Solution Approach 2:
Rather than adding excessive phosphate to maximize dealumination prevention, the invention uses a controlled, partial amount of phosphorus (0.01-1.0% by mass). This partial action is sufficient to protect the zeolite while avoiding the harmful side effect of excessive phosphoric acid formation that would accelerate stainless steel corrosion.
3Duration of action of stationary object
If high phosphorus content is used to prevent dealumination, then catalyst stability is improved, but corrosion of industrial equipment worsens
Solution Approach 1:
The invention establishes an optimal parameter range for phosphorus content (0.01-1.0% by mass) that balances two opposing requirements: sufficient phosphorus to stabilize the zeolite structure and prevent dealumination, but limited phosphorus to avoid forming excessive phosphoric acid that would corrode stainless steel equipment.
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 silica composite effectively prevents zeolite dealumination in high-temperature steam and reduces stainless steel corrosion, maintaining catalyst performance and integrity in propylene production processes.
Implementation Method 1
the silica composite is hardly subject to dealumination of zeolite even in a high-temperature steam atmosphere
Implementation Method 2
calcining the dried product
Implementation Method 3
drying the raw material mixture to obtain a dried product
Implementation Method 4
bringing a solution of phosphate into contact with the zeolite and/or the dried product
Data Source
AI summary
The present invention provides a method for producing a silica composite by the steps of: preparing a raw material mixture containing silica and zeolite; drying the raw material mixture to obtain a dried product; and calcining the dried product, wherein the method comprising the step of allowing the raw material mixture to contain phosphoric acid and/or phosphate or bringing a solution of phosphoric acid and/or phosphate into contact with the zeolite and/or the dried product, or a combination thereof to thereby adjust a phosphorus content in the silica composite to 0.01 to 1.0% by mass based on the total mass of the silica composite.