Titanium Zeolite Catalyst Regeneration via Water Washing
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Solution Overview
Problem
Current methods for regenerating titanium-containing zeolites used in olefin epoxidation are complex, costly, and inefficient, often requiring expensive solvents like methanol and hydrogen peroxide, which are difficult to handle and recover.
Innovation Solution
A process involving continuous propylene oxide production using a titanium-containing zeolite catalyst, followed by washing with a high-water liquid aqueous system and optional calcination, allows for effective regeneration of the catalyst without the need for expensive solvent recovery and with maintained catalytic activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If expensive solvents like methanol and hydrogen peroxide are used for catalyst regeneration, then catalytic activity can be restored, but the process becomes costly and complex with difficult solvent recovery
Solution Approach 1:
The patent replaces expensive, difficult-to-recover solvents (methanol, hydrogen peroxide) with water, which is inexpensive and easily handled. The washing step uses water to remove organic residues from the catalyst, eliminating the need for complex solvent recovery systems while effectively restoring catalytic activity.
Solution Approach 2:
The patent changes the chemical parameter of the washing medium from organic solvents (methanol, hydrogen peroxide) to water. This parameter change simplifies the regeneration process, reduces costs, and eliminates recovery complexity while maintaining effective catalyst regeneration through water washing followed by optional calcination.
2Reliability
If multiple sequential steps including pretreatment with water or alcohol followed by hydrogen peroxide mixture are used, then regeneration can be achieved, but the process becomes time-consuming and requires work-up procedures
Solution Approach 1:
The patent extracts the essential regeneration function to a single water washing step, removing unnecessary intermediate steps. The water washing effectively removes organic residues and restores catalytic activity, making subsequent hydrogen peroxide treatment and work-up procedures unnecessary, thus significantly reducing regeneration time.
Solution Approach 2:
The water washing step performs multiple functions simultaneously: it removes organic residues, cleans the catalyst surface, and prepares the catalyst for reuse. This self-service approach eliminates the need for sequential pretreatment and hydrogen peroxide mixture steps, reducing overall regeneration time while maintaining effectiveness.
3Reliability
If catalyst replacement is performed instead of regeneration, then fresh catalytic activity is obtained, but the cost and environmental impact increase
Solution Approach 1:
The patent recovers the spent catalyst by washing it with water to remove organic residues, then optionally calcining to restore active sites. This recovery process allows the catalyst to be reused multiple times, preventing catalyst waste and reducing the need for continuous replacement, thereby lowering costs and environmental impact.
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 process simplifies catalyst regeneration, reduces costs, and maintains or enhances catalytic activity, enabling the reuse of titanium-containing zeolites in olefin epoxidation reactions.
Implementation Method 1
washing the catalyst in the reactor containing the catalyst with a liquid aqueous system containing at least 95 weight-% water
Implementation Method 2
calcining the catalyst obtained from (c) after having repeated the sequence of steps (a) to (c) n times, wherein the calcining is performed at a temperature of the catalyst in the range of from 300 to 600 °C using a gas stream comprising oxygen
Implementation Method 3
introducing a feed stream comprising propene, hydrogen peroxide or a hydrogen peroxide source, and an organic solvent into a reactor containing a catalyst comprising the titanium containing zeolite of MWW framework structure as catalytically active material
Data Source
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AI summary
The invention relates to process for the regeneration of a catalyst comprising a titanium containing zeolite as catalytically active material comprising a stage comprising introducing a feed stream comprising propene, hydrogen peroxide or a hydrogen peroxide source, and an organic solvent into a reactor containing a catalyst comprising the titanium containing zeolite, subjecting the feed stream in the reactor to epoxidation conditions in the presence of the catalyst, removing a product steam comprising propylene oxide and the organic solvent from the reactor, stopping introducing the feed stream, washing the catalyst with a liquid aqueous system and calcining the washed catalyst.