Catalyst Regeneration via Oxychlorination and Chlorine Stripping
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Solution Overview
Problem
Conventional catalyst regeneration methods for Group 10 metal-containing zeolites with high metal-to-aluminum ratios are ineffective in redispersing noble metal particles within zeolite pores, leading to agglomeration and reduced catalyst activity.
Innovation Solution
A process involving oxychlorination and chlorine stripping steps is employed to regenerate deactivated catalysts, using a gaseous stream with chlorine and oxygen sources to disperse Group 10 metal particles on the catalyst surface and increase the O/Cl ratio of Group 10 metal chlorohydrates, effectively redispersing the metal within the microporous crystalline aluminosilicate structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional oxidative coke removal methods are used, then coke is effectively removed from the catalyst, but the supported metal particles agglomerate and catalyst activity is reduced
Solution Approach 1:
The invention changes the chemical environment parameters by introducing chlorine-containing compounds during the regeneration process. This creates a chlorinating atmosphere that prevents metal particle agglomeration while maintaining effective coke removal, thus resolving the contradiction between coke removal effectiveness and catalyst activity preservation
Solution Approach 2:
Chlorine-containing compounds act as an intermediary substance that mediates between the oxidative coke removal process and the metal particles. The chlorine forms volatile metal chlorides that prevent direct oxidation-induced agglomeration, enabling both effective coke removal and metal particle stability
2Ease of manufacture
If current redispersion methods are used, then metal particles can be redispersed on alumina and silica supports, but they are ineffective for zeolite supported catalysts with high metal-to-aluminum ratios
Solution Approach 1:
The invention develops a universal redispersion method using chlorine-containing compounds that works across multiple support types including alumina, silica, and zeolites. The method adapts to different metal-to-aluminum ratios and support structures, making it universally applicable to various catalyst systems rather than being limited to specific support materials
Solution Approach 2:
The invention changes the chemical parameters by introducing chlorine-containing compounds that enable redispersion on zeolite supports with high metal-to-aluminum ratios. This chemical modification allows the process to work on previously difficult-to-regenerate catalysts, expanding the method's versatility
3Productivity
If catalysts with high Group 10 metal-to-aluminum ratios are used, then catalyst activity is enhanced, but conventional regeneration methods fail to redispersing metal particles within zeolite pores
Solution Approach 1:
The invention changes the chemical environment by introducing chlorine-containing compounds during regeneration. This creates conditions that enable effective redispersion of metal particles even in catalysts with high metal-to-aluminum ratios, maintaining both high catalyst activity and reliable regeneration
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
This method effectively regenerates catalysts with restored activity and selectivity, maintaining or exceeding the performance of fresh catalysts by dispersing Group 10 metal particles within the zeolite pores, even for high metal-to-aluminum ratio materials.
Implementation Method 1
The processes comprise an oxychlorination step comprising contacting the catalyst with a first gaseous stream comprising a chlorine source and an oxygen source under conditions effective for dispersing at least a portion of the at least one Group 10 metal on the surface of the catalyst and for producing a first Group 10 metal chlorohydrate
Implementation Method 2
The processes further comprise a chlorine stripping step comprising contacting the catalyst with a second gaseous stream comprising an oxygen source, and optionally a chlorine source, under conditions effective for increasing the O/Cl ratio of the first Group 10 metal chlorohydrate to produce a second Group 10 metal chlorohydrate
Implementation Method 3
The processes for chemical conversion of a hydrocarbon feedstock comprise the step of contacting a hydrocarbon feedstock with a catalyst comprising at least one Group 10 metal and a microporous crystalline aluminosilicate in a reaction zone to form a hydrocarbon reaction product
Data Source
AI summary
Disclosed are processes for regenerating catalysts comprising at least one Group 10 metal and a microporous crystalline aluminosilicate having a having a molar ratio of Group 10 metal to Al of greater than or equal to about 0.007:1, and hydrocarbon conversion processes including such regeneration processes. In an aspect, the regeneration processes comprise an oxychlorination step comprising contacting the catalyst with a first gaseous stream comprising a chlorine source and an oxygen source under conditions effective for dispersing at least a portion of the at least one Group 10 metal on the surface of the catalyst and for producing a first Group 10 metal chlorohydrate. The processes further comprise a chlorine stripping step comprising contacting the catalyst with a second gaseous stream comprising an oxygen source, and optionally a chlorine source, under conditions effective for increasing the O/Cl ratio of the first Group 10 metal chlorohydrate to produce a second Group 10 metal chlorohydrate.