Fiber Composite Ceramic Reactor Internals for High-Temperature Stability
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Solution Overview
Problem
Reactor systems for heterogeneously catalyzed gas-phase reactions at high temperatures face issues with thermal expansion and strength degradation of metal catalyst baskets, leading to gas bypass, catalyst particle crushing, and reduced operating times due to differential expansion between catalyst baskets and grating supports.
Innovation Solution
The use of fiber composite ceramic materials for internal elements within the reactor, which exhibit reduced thermal expansion and increased high-temperature strength, preventing gas bypass and maintaining structural integrity, and allowing for the use of dummy elements to maintain reactor performance across varying loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal alloys are used for catalyst baskets, then the baskets can be manufactured with sufficient strength at room temperature, but the baskets expand thermally at high reaction temperatures causing catalyst bed depression and gas bypass
Solution Approach 1:
The patent applies composite materials by combining ceramic fibers (such as alumina, silica, or mullite) with metal alloys to create a composite catalyst basket structure. The ceramic fiber component provides low thermal expansion and high-temperature stability, while the metal alloy component provides mechanical strength and structural integrity. This composite construction resolves the contradiction by integrating materials with complementary properties that individually cannot achieve both low thermal expansion and sufficient strength.
2Ease of manufacture
If metal catalyst baskets are used, then the structure is simple and easy to manufacture, but the baskets lose strength at high reaction temperatures leading to structural failure
Solution Approach 1:
The composite structure combines ceramic fibers embedded in a metal alloy matrix, where the ceramic component maintains structural stability at high temperatures while the metal matrix provides ductility and toughness. This composite approach maintains ease of manufacture through established composite fabrication techniques while dramatically improving high-temperature strength retention.
3Strength
If cooling tubes are used to support the catalyst grating, then the grating strength is maintained at high temperatures, but differential thermal expansion causes distortion and rupture of internals
Solution Approach 1:
The patent applies local quality by creating a distributed network of cooling tubes throughout the catalyst basket structure rather than relying on a few large support points. This distributes the thermal management function locally across the entire structure, allowing each local region to expand and contract uniformly with its surroundings, thereby preventing differential expansion and maintaining dimensional stability of the internals.
4Productivity
If the reactor operates at high temperatures, then the desired gas-phase reactions proceed efficiently, but the catalyst bed develops bypass paths reducing reaction efficiency
Solution Approach 1:
The composite catalyst basket structure prevents the thermal deformation that leads to catalyst bed bypass. The low thermal expansion ceramic fiber component maintains the basket's dimensional stability at high temperatures, ensuring uniform catalyst bed support and preventing the formation of bypass paths, thereby maintaining both reaction efficiency and catalyst bed integrity during prolonged high-temperature operation.
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 fiber composite ceramic materials ensure stable operation at high temperatures, reducing gas bypass and catalyst degradation, thereby extending reactor lifespan and maintaining yield and reducing economic losses.
Implementation Method 1
the linear expansion of a typical nickel-chromium alloy, for example the highly heat-resistant alloy InconelTM 600 (material number 2.4816) having a coefficient of linear expansion of 18-20×10−6 1/K, being about 80-90 mm at a reaction temperature of 1000° C.
Implementation Method 2
the one or more internal elements is/are at least partly, preferably entirely, made of a fiber composite ceramic material
Implementation Method 3
reactors for carrying out heterogeneously catalyzed gas-phase reactions
Data Source
AI summary
The invention relates to a reactor for carrying out heterogeneously catalyzed gas-phase reactions, having an internal element (11, 35) or a plurality of internal elements (11, 35) which are arranged in succession in the flow direction of the gas mixture of the heterogeneously catalyzed gas-phase reaction through the reactor (10), where the internal elements extend over the entire reactor cross section, wherein the one or more internal elements (11, 35) is/are at least partly made of a fiber composite ceramic material.