Separate Dimerization and Alkylation Catalysts for Ethylene Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current commercial alkylation processes cannot effectively utilize ethylene due to its low reactivity and the deactivation of dimerization catalysts by coke formation, which requires impractical regeneration conditions, limiting the production of high octane alkylate.
Innovation Solution
A method involving separate dimerization and alkylation catalysts, where the dimerization catalyst converts ethylene to butene, and the alkylation catalyst reacts butene with isobutane, using distinct catalysts to prevent coke formation and enable regeneration, allowing for the production of high octane alkylate from ethylene and isobutane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single catalyst is used for both dimerization and alkylation, then the process can convert ethylene to high octane alkylate, but the dimerization catalyst deactivates due to coke formation requiring impractical regeneration conditions
Solution Approach 1:
The patent divides the catalytic function into two separate catalysts: a dimerization catalyst (e.g., nickel, palladium, or chromium-based) and an alkylation catalyst (e.g., solid acid catalyst like zeolite or sulfonated resin). This segmentation prevents coke deactivation of the dimerization catalyst because the alkylation catalyst handles the olefin consumption, reducing oligomerization side reactions that cause coking.
Solution Approach 2:
The patent introduces butene as an intermediate product that bridges the dimerization and alkylation steps. Ethylene is first dimerized to butene by the dimerization catalyst, then butene is alkylated with isobutane by the alkylation catalyst. This intermediary approach allows each catalyst to operate optimally without the other's deactivation issues.
2Ease of repair
If oxygen is introduced to regenerate the dimerization catalyst, then coke can be removed, but hazards and harsh conditions are introduced
Solution Approach 1:
The patent changes the regeneration parameters by using mild oxidation conditions or alternative methods such as hydrogen treatment or thermal treatment in inert atmosphere, avoiding harsh oxygen-based regeneration. This maintains catalyst activity while eliminating safety hazards associated with oxygen introduction.
Solution Approach 2:
The patent converts the harmful effect of coke formation into a manageable issue by using the separate catalyst configuration, where the alkylation catalyst's presence reduces further coking, and regeneration can be performed under milder conditions that convert the coke slowly and safely without introducing oxygen hazards.
3Productivity
If liquid acid catalysts are used for alkylation, then ethylene cannot be activated due to stable ethyl ether formation, but high octane alkylate can be produced from other olefins
Solution Approach 1:
The patent changes the catalyst type from liquid acid (HF, H2SO4) to solid acid catalysts or metal-based dimerization catalysts that can activate ethylene without forming stable ethyl ethers. This allows ethylene to be converted to butene, which then undergoes alkylation to produce high octane alkylate, expanding the process versatility to include ethylene feedstock.
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
This approach enables efficient production of high octane alkylate, maintaining catalyst activity over time and simplifying regeneration, while avoiding the hazards of oxygen introduction and harsh conditions.
Implementation Method 1
reacting ethylene and isobutane under catalytic conversion conditions in the presence of a first catalytic material which includes a dimerization catalyst
Implementation Method 2
a second catalytic material which includes an alkylation catalyst, wherein the first and second catalytic materials are separate and distinct from each other
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A method of producing a high octane alkylate from ethylene and isobutane by reacting ethylene and isobutane under catalytic conversion conditions. The ethylene and isobutane are contacted with a first catalytic material comprising a dimerization catalyst (i.e, for dimerizing ethylene) and a second catalytic material comprising an alkylation catalyst. The first and second catalytic materials are separate and distinct from each other. A high octane alkylate is recovered as a result of reacting the ethylene and isobutane in the presence of the first and second catalytic materials.