Selective Hydrogenation Catalyst Shell Structure for C4 Olefin Purification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metathesis catalysts used in industrial processes for C4-olefin mixtures deactivate quickly due to impurities, particularly 1,2-dienes, which hinders the production of high 1-butene content necessary for producing 3-hexene, leading to inefficient and costly operations.
Innovation Solution
A C4-olefin mixture with reduced 1,2-dienes content (less than 10 ppm) and controlled 1,3-butadiene levels (100-500 ppm) is achieved through selective hydrogenation using a catalyst with a metal of group VIII and a promoter, such as palladium and silver, distributed in a shell structure on an oxidic support, minimizing catalyst deactivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If selective hydrogenation is used to remove 1,2-dienes, then 1,2-dienes content is reduced, but 1-butene is isomerized to 2-butene
Solution Approach 1:
The catalyst has a specific shell structure with hydrogenation metal (Group VIII) and promoter (silver) distributed in a shell around the support core, creating local active sites with selective properties that favor 1,2-diene hydrogenation over 1-butene isomerization
Solution Approach 2:
The patent specifies precise operating conditions including temperature range (20-100°C), pressure (5-50 barg), and catalyst composition parameters that optimize the selectivity of the hydrogenation reaction to remove 1,2-dienes while preserving 1-butene
2Productivity
If metathesis catalysts are used for C4-olefin mixtures, then 3-hexene production is enabled, but catalyst deactivates quickly due to impurities
Solution Approach 1:
The selective hydrogenation process is performed as a pretreatment step before metathesis to remove deactivating impurities (1,2-dienes and acetylenic compounds) from the C4 feed, preventing catalyst deactivation in the subsequent metathesis reaction
Solution Approach 2:
The patent converts the potentially harmful effect of 1,2-dienes (which cause catalyst deactivation) into a controlled process by selectively hydrogenating them to useful products while maintaining 1-butene content, thus transforming a problem into a solution
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 process maintains catalyst activity and achieves a high 1-butene content, enabling prolonged metathesis reaction efficiency and increased production of 2-pentene and/or 3-hexene without substantial deactivation, thus optimizing industrial processes.
Implementation Method 1
a) carrying out selective hydrogenation of a C4 stream from a steam cracker over a hydrogenation catalyst
Implementation Method 2
b) reacting the C4-olefin mixture in a metathesis reaction over a metathesis catalyst to give 2-pentene and/or 3-hexene
Data Source
AI summary
A C4-olefin mixture having a 1,3-butadiene content of from 100 to 500 ppm and a content of 1,2-dienes of less than 10 ppm is described. The present invention further provides a process for preparing this C4-olefin mixture and provides for its use in a metathesis reaction for preparing 2-pentene and/or 3-hexene.