Catalyst Pore Depth Distribution for Flue Gas Reactivation
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Solution Overview
Problem
Catalyst bases used for reducing nitrogen oxides in flue gases experience a decrease in desired catalytic activity and an increase in undesired side reactions over time, leading to the need for reactivation, where existing methods result in uneven distribution of catalytically relevant substances, favoring undesired reactions in deeper pore regions.
Innovation Solution
A method where catalytically relevant substances are introduced into the pores of the catalyst base using a transport fluid, with a controlled distribution that decreases with pore depth, ensuring higher activity in regions closer to the contact area and reducing undesired reactions in deeper regions, using a combination of blocking and transport fluids to achieve an unequal distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If catalytically relevant substances are introduced uniformly into all pores, then the catalyst base achieves initial catalytic activity, but undesired side reactions increase in deeper pore regions over time
Solution Approach 1:
The patent applies local quality by creating a non-uniform distribution of catalytically relevant substances within the pore structure. The substance concentration is highest near the contact area and decreases with pore depth, ensuring that active centers are predominantly located in regions where flue gas actually flows. This localized distribution maintains catalytic activity while minimizing undesired side reactions in deeper pore regions that are not accessible to the gas stream.
Solution Approach 2:
The patent segments the pore system into different depth zones with different substance concentrations. By introducing the catalytically relevant substance in a controlled manner that creates depth-dependent distribution, the pore structure is effectively divided into active regions (near contact area) and inactive regions (deep pores), allowing the system to benefit from catalysis while avoiding the harmful effects of over-saturation in inaccessible regions.
2Duration of action of moving object
If the catalyst base is used for an extended period, then production experience gains are achieved, but catalytic activity decreases and reactivation becomes necessary
Solution Approach 1:
The patent applies preliminary action by pre-distributing the catalytically relevant substance in an optimized non-uniform pattern before the catalyst enters service. This preliminary configuration ensures that the catalyst maintains high activity throughout its service life, as the substance is already positioned in the optimal locations (near contact areas) where it is most needed. This prevents the rapid deactivation that would occur with uniform distribution and extends the catalyst's operational lifespan.
3Ease of manufacture
If uniform substance distribution is used in reactivation, then manufacturing simplicity is maintained, but substance accumulation in deeper pores favors undesired reactions
Solution Approach 1:
The patent applies local quality during reactivation by using a transport fluid that naturally penetrates pores to different extents based on depth. The catalytically relevant substance dissolved in this fluid is deposited preferentially in regions closer to the contact area, creating the desired non-uniform distribution without requiring complex application equipment or multiple processing steps. This maintains manufacturing simplicity while achieving the beneficial localized concentration profile.
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 method maintains high catalytic activity while minimizing undesired side reactions, extending the catalyst's life, reducing operational risks, and avoiding additional maintenance costs by ensuring catalytically active centers are predominantly in regions accessible to the flue gas, thus reducing sulfur trioxide production and its associated issues.
Implementation Method 1
catalytically relevant substances are introduced into the pores of the catalyst base using a transport fluid
Implementation Method 2
introducing at least one catalytically relevant substance into pores of the catalyst base (100) by use of a transport fluid (200)
Implementation Method 3
the catalytically relevant substance remains on pore wall areas after removal of the transport fluid
Implementation Method 4
NOx is transformed to water and nitrogen using NH3 (ammonia). In the presence of catalysts, the reaction runs faster and/or at a lower temperature
Implementation Method 5
The streaming fluid and the reactants (within the fluid) enter (diffuse) into the pore system
Implementation Method 6
they come into contact with the active centers located at the pore wall areas and there they are adsorbed
Data Source
AI summary
A method for treating a catalyst base that comprises a contact area of porous material. A fluid, such as a flue gas stream, can be conducted along the contact area. A catalytically relevant substance is introduced into pores of the catalyst base using a transport fluid and remains on pore wall areas after removal of the transport fluid. The introduction is carried out such that an amount of the catalytically relevant substance relative to the surface remains on the pore wall areas as a function of location within the pore and decreases within the pore after exceeding a specific pore depth. A blocking fluid can first be introduced into pore regions beyond the specific pore depth, thus blocking these regions when transport fluid containing the catalytically relevant substance is introduced.