Olefin Production Catalyst with Hydrothermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dehydrogenation catalysts for producing olefins from lighter alkanes face challenges such as low yields due to equilibrium limitations and rapid deactivation at high temperatures, with existing solutions not fully addressing issues of catalyst stability and selectivity.
Innovation Solution
A catalyst composition using a microsphere support material with an inorganic nitrate binder, high surface area silica/silica-alumina, and hydrothermally stable alumina, doped with rare earth elements, combined with a vanadium-chromium complex and alkali or alkaline metal oxides, to enhance hydrothermal stability and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional dehydrogenation catalysts (alumina supported chromium oxide, platinum on alumina, noble metal promoted zinc aluminate spinel) are used, then dehydrogenation activity is achieved, but catalyst deactivation occurs rapidly at high temperatures
Solution Approach 1:
The patent employs a composite catalyst system comprising Cr2O3 as the active phase supported on a composite carrier containing Al2O3, SiO2, and TiO2. This composite structure combines the high activity of chromium oxide with the thermal stability of the mixed oxide support, resolving the contradiction between activity and stability at high temperatures.
Solution Approach 2:
The patent modifies the chemical composition parameters of the catalyst by incorporating specific ratios of Al2O3 (60-80 wt%), SiO2 (10-30 wt%), and TiO2 (5-15 wt%), along with controlled amounts of Cr2O3 (0.1-5 wt%). These parameter changes optimize both activity and resistance to thermal deactivation.
2Productivity
If alumina supported chromium oxide catalyst is used for high dehydrogenation activity, then conversion is improved, but rapid coke formation occurs leading to frequent regeneration requirements
Solution Approach 1:
The patent introduces localized basic sites on the catalyst surface through the addition of alkali metal oxides (Na2O: 0.1-5 wt%, K2O: 0.1-5 wt%) and alkaline earth metal oxides (MgO: 0.1-5 wt%, CaO: 0.1-5 wt%). These localized basic sites specifically address coke formation without compromising the overall conversion activity, thereby extending catalyst life between regenerations.
Solution Approach 2:
The SiO2 and TiO2 components act as intermediaries between the Cr2O3 active phase and the alumina support, modifying the surface properties to reduce coke deposition while maintaining high conversion rates. The silica and titania create a more stable interface that prevents rapid deactivation.
3Productivity
If frequent high temperature regeneration cycles are performed, then coke is removed and activity is restored, but catalyst loss and deactivation increase due to hydrothermal instability
Solution Approach 1:
The patent changes the thermal and hydrothermal stability parameters of the catalyst by incorporating TiO2 (5-15 wt%) alongside Al2O3 and SiO2. This compositional modification raises the threshold for hydrothermal degradation, allowing the catalyst to withstand frequent regeneration cycles at 550-750°C without significant material loss or permanent deactivation.
4Ease of manufacture
If conventional catalyst formulations are used, then manufacturing simplicity is maintained, but selectivity and stability are insufficient
Solution Approach 1:
The patent develops a composite catalyst formulation that combines Cr2O3, Al2O3, SiO2, TiO2, and small amounts of alkali/alkaline earth metal oxides. While the composition is more complex than conventional catalysts, the manufacturing process remains relatively simple using standard impregnation and calcination techniques, achieving both improved selectivity (>70%) and stability.
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 solution provides superior hydrothermal stability, high alkane conversion (above 50%), and high olefin selectivity (above 70%), extending catalyst life and improving reaction efficiency.
Implementation Method 1
microsphere support material comprises binder, high surface area silica/silica-alumina and hydrothermally stable alumina
Implementation Method 2
Catalytic oxidative dehydrogenation (ODH) is an emerging technology, which can eliminate some of the drawbacks associated with the conventional cracking processes
Implementation Method 3
hydrothermally stable alumina
Data Source
AI summary
The present invention provides a catalyst composition for the production of olefins from lighter alkanes by oxidative dehydrogenation route and methods of making the dehydrogenation catalyst composites.