Fe-K-Ce-Rare Earth Dehydrogenation Catalyst for Styrene
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Solution Overview
Problem
Current catalysts for dehydrogenating ethylbenzene to produce styrene monomer lack high activity in low-temperature regions, leading to reduced reaction yield and mechanical strength, and are not cost-effective or environmentally friendly.
Innovation Solution
A catalyst comprising iron, potassium, cerium, and a rare earth element such as yttrium or dysprosium, which maintains high activity and selectivity across a wide temperature range, reducing activity loss over time and enhancing mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional Fe-K-Ce catalysts are used, then high activity in high-temperature regions is achieved, but activity in low-temperature regions is insufficient
Solution Approach 1:
The patent applies composite materials by combining Fe-K-Ce catalyst with rare earth elements (yttrium, dysprosium, or a mixture) to create a multi-component catalyst system. This composite structure enables the catalyst to maintain high activity across both high-temperature and low-temperature regions, resolving the contradiction between temperature range coverage and productivity.
Solution Approach 2:
The patent changes the chemical composition parameters of the catalyst by introducing rare earth elements at specific concentrations (0.01-1% for individual rare earths, or 0.005-0.5% for mixtures). This parameter modification transforms the catalyst's temperature-dependent activity profile, enabling high performance across a broader temperature range while maintaining productivity.
2Productivity
If additional elements are added to improve activity, then catalytic performance is enhanced, but production cost increases
Solution Approach 1:
The patent optimizes the concentration parameters of rare earth elements to achieve the lowest effective dosage (0.01-1% for individual rare earths, 0.005-0.5% for mixtures). This parameter optimization reduces material costs while maintaining enhanced catalytic activity, resolving the contradiction between productivity improvement and manufacturing cost.
Solution Approach 2:
The patent uses small quantities of rare earth elements as catalyst additives rather than bulk materials. This approach incorporates expensive elements in minimal amounts necessary to achieve performance enhancement, making the overall catalyst economically viable despite the high unit cost of rare earth elements.
3Strength
If catalyst pellets are shaped to withstand stress, then mechanical strength is improved, but flow interruption may occur
Solution Approach 1:
The patent creates a composite catalyst structure incorporating rare earth elements that enhance both mechanical strength and flow characteristics. The multi-component composition (Fe-K-Ce-rare earth) provides improved pellet integrity under stress while maintaining adequate flow continuity, resolving the contradiction between strength and operational ease.
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 achieves high conversion and selectivity in both high- and low-temperature regions, improving reaction yield and productivity while maintaining mechanical strength and reducing energy consumption.
Implementation Method 1
a dehydrogenation catalyst to be used in a process for producing an alkenylaromatic compound through dehydrogenation reaction by contacting an alkylaromatic compound diluted with water vapor with the catalyst
Implementation Method 2
The dehydrogenation reaction of ethylbenzene is an endothermic reaction accompanied by volume expansion as represented by reaction formula (1) below
Implementation Method 3
it is believed that potassium oxide maintains the activity through the facilitation of water gas shift reactions between the carbonaceous substance deposited on the surface of the catalyst and steam
Data Source
Figure 1
AI summary
[Problem to be Solved] The object of the present invention is to provide a catalyst which is highly active in dehydrogenation reaction of an alkylaromatic hydrocarbon not only in high-temperature regions (e.g. 600 to 650°C) as found in the inlet of a catalyst bed in an apparatus for the production of SM but also in low-temperature regions (e.g. under 600°C) as found in the outlet of a catalyst bed in an apparatus for the production of SM, where the temperature decreases as a result of endothermic reaction; and a process for producing the catalyst; and a dehydrogenation process using the catalyst. [Solution] The object is achieved through a catalyst for dehydrogenating an alkylaromatic hydrocarbon, the catalyst containing iron (Fe), potassium (K), and cerium (Ce), and at least one rare earth element other than cerium.