Domed Heterogeneous Catalysts for Steam Reforming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shaped heterogeneous catalysts with through holes and flutes experience reduced effective geometric surface area and increased pressure drop when packed in a bed due to misalignment and turbulent flow, which affects catalytic performance.
Innovation Solution
Designing catalyst units with domed ends and strategically positioned circular holes, along with optional flutes, to optimize geometric surface area, strength, and reduce pressure drop by minimizing turbulence and enhancing radial mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If catalyst particles are made smaller to increase surface area and catalytic activity, then catalytic activity is improved, but pressure drop through the catalyst bed increases and throughput decreases
Solution Approach 1:
The catalyst is segmented into multiple small particles, each containing multiple through-holes. This segmentation increases the total surface area for catalytic activity while the through-holes in each particle allow reactants to pass through more easily, reducing the overall pressure drop in the catalyst bed.
Solution Approach 2:
The invention adds a third dimension to the catalyst particles by creating through-holes that extend through the particle depth. This dimensional change allows reactants to access catalytic sites from both external and internal surfaces, increasing effective surface area without requiring smaller particle sizes that would increase pressure drop.
2Productivity
If through-holes are added to catalyst particles to increase geometric surface area and reduce pressure drop, then throughput is improved, but effective geometric surface area is reduced due to misalignment in packed beds
Solution Approach 1:
The catalyst particles are given a spherical or spheroidal shape with curved surfaces. This curvature allows the particles to pack more uniformly in the catalyst bed, reducing misalignment issues and ensuring that through-holes remain properly oriented for reactant flow, thereby maintaining effective geometric surface area while improving throughput.
3Area of stationary object
If flutes and holes are added to increase theoretical geometric surface area, then surface area is improved, but pressure drop increases due to turbulent flow and misalignment in packed beds
Solution Approach 1:
The through-holes are strategically positioned and sized differently within each catalyst particle to optimize local flow characteristics. This local quality variation ensures that reactants experience smoother flow through the particles, reducing turbulence and pressure drop while still providing increased geometric surface area for catalysis.
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 catalyst units with domed ends and circular holes exhibit improved effective geometric surface area and reduced pressure drop, leading to enhanced catalytic performance and radial heat transfer in packed beds.
Implementation Method 1
the flowing medium to display less turbulent behaviour and reduce the overall energy losses experienced in the bed
Implementation Method 2
the domed surfaces will encourage radial mixing of the flow in the tube to compensate for the loss in turbulent mixing with respect to the overall radial heat transfer performance of the bed
Implementation Method 3
the domed surfaces will encourage radial mixing of the flow in the tube to compensate for the loss in turbulent mixing with respect to the overall radial heat transfer performance of the bed
Data Source
Figure 1~2
AI summary
A catalyst unit is described in the form of a cylinder having a length C and diameter D, which has one or more holes extending therethrough, wherein said cylinder has domed ends of lengths A and B, such that (A+B+C)/D is in the range 0.50 to 2.00, and (A+B)/C is in the range 0.40 to 5.00. The catalyst or catalyst unit preferably has one or more flutes running along its length. The catalyst may be used particularly in steam reforming reactors.