Zeolite Catalyst Extrusion with Inorganic Binder
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Zeolite-based catalysts face challenges in extrusion due to their specific properties and morphology, requiring higher binder proportions for mechanical stability, which reduces catalytic activity per unit volume.
Innovation Solution
A process involving diatomaceous earth particles with mesoporosity, treated through hydrothermal crystallization and ion-exchange to form a zeolite-based catalyst composition with a high proportion of ion-exchanged zeolite as a binder, enhancing mechanical stability and catalytic activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If higher proportions of binder are used to achieve sufficient mechanical stability of zeolite-based catalysts, then mechanical stability is improved, but the proportion of catalytically active component decreases, reducing specific catalytic activity per unit volume
Solution Approach 1:
The patent changes the chemical composition parameters of the binder from conventional organic binders to inorganic binder components (such as water glass, alumina, or silica) that can serve dual functions: providing mechanical stability and contributing to catalytic activity. This parameter change allows the binder to replace part of the catalytically active zeolite material while maintaining or enhancing mechanical strength.
Solution Approach 2:
The inorganic binder components are designed to perform multiple functions simultaneously: they provide mechanical stability as a binder, contribute to the structural integrity of the extruded catalyst body, and when catalytically activated through hydrothermal treatment, they also provide catalytic activity for SCR reactions. This multi-functionality reduces the need for separate catalytically active materials.
2Quantity of substance
If zeolites are used as catalytically active component, then catalytic activity is improved, but extrusion becomes more difficult and mechanical stability is reduced
Solution Approach 1:
The patent creates a composite material system where inorganic binder components (water glass, alumina, silica) are combined with catalytically active zeolite materials. The inorganic binders provide the necessary mechanical strength and extrudability, while the zeolite components provide catalytic activity. The composite structure allows both properties to coexist without compromising either.
Solution Approach 2:
The patent modifies the rheological and mechanical parameters of the catalyst composition by introducing inorganic binder components that improve extrudability and green strength. These binders adjust the flow characteristics of the extrusion mass and provide sufficient mechanical strength during the extrusion process, making manufacturing easier while maintaining high catalytic activity.
3Quantity of substance
If inorganic binder components are catalytically activated through hydrothermal treatment, then catalytic activity is improved, but additional processing steps and time are required
Solution Approach 1:
The patent merges the binder activation process with the catalyst formation process. The inorganic binder components are catalytically activated through hydrothermal treatment at temperatures of 80-200°C over periods of 1-10 days, which simultaneously activates the catalytic activity of the binder and completes the formation of the extruded catalyst body. This combined approach eliminates separate activation steps.
Solution Approach 2:
The inorganic binder components are prepared and positioned in the extruded catalyst body before final catalytic activation. The binders are already in place providing mechanical strength during extrusion and drying, and then the catalytic activation is performed as a preliminary treatment before the catalyst enters service. This preliminary action allows the catalyst to be structurally ready before catalytic functionality is fully developed.
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 enables the production of an extrudable catalyst with high stability and catalytic activity, ensuring efficient nitrogen oxide reduction in exhaust gases while optimizing the use of zeolitic material.
Implementation Method 1
hydrothermal crystallisation at a temperature of 80 to 200°C, autogenous pressurisation over a reaction time of one to ten days to form crystalline material
Implementation Method 2
ion-exchanging the zeolite with iron or copper to form an ion-exchanged zeolite
Implementation Method 3
extruding a catalyst composition to produce a catalyst body
Implementation Method 4
calcining the crystalline material to form a zeolite, wherein the crystalline material is calcined at a temperature of 400 to 800°C
Data Source
Figure 1
Figure 2~4
AI summary
To be able to produce an SCR catalyst (2), in particular one having a zeolite fraction (Z) as catalytically active fraction, in a reliable process and at the same time achieve good catalytic activity of the catalyst (2), an inorganic binder fraction (B) which is catalytically inactive in the starting state and has been treated to develop catalytic activity is mixed into a catalyst composition (4). The inorganic binder component for the binder fraction (B) is, in the starting state, preferably porous particles (10), in particular diatomaceous earth, which display mesoporosity. To effect catalytic activation, the individual particles (10) are either coated with a catalytically active layer (12) or transformed into a catalytically active zeolite (14) with maintenance of the mesoporosity.