Oligomerization Process for C8 Olefins with Low Isoindex
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Solution Overview
Problem
The existing oligomerization processes for producing C8 olefins with low isoindex are inefficient when the C4 stream has a low 1-butene content, as they require high conversion rates and specific raw materials, limiting their adaptability to current raw material availability and increasing costs.
Innovation Solution
A process that limits the conversion of butenes in the first reaction zone to a specific range (5-40% by weight) and uses a high recycle rate, combined with low reaction temperatures, to produce C8 olefins with an isoindex less than 1.2, even when the 1-butene concentration is below thermodynamic equilibrium, allowing for the use of C4 streams with minimal 1-butene content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high conversion rates are used in existing oligomerization processes, then C8 olefin production is improved, but the process becomes inefficient when C4 stream has low 1-butene content
Solution Approach 1:
The patent changes the conversion rate parameter to a specific range (5-40% by weight) and introduces a recycle rate parameter (≥100%) to adapt the process to C4 streams with low 1-butene content. This allows the process to maintain C8 olefin production efficiency while becoming adaptable to varying raw material compositions, resolving the contradiction between productivity and adaptability.
2Productivity
If high conversion rates are used, then C8 olefin production is improved, but process costs increase
Solution Approach 1:
The patent optimizes the conversion rate parameter to a moderate range (5-40% by weight) rather than using high conversion rates, and introduces a high recycle rate (≥100%) to maintain productivity. This parameter optimization reduces process costs while preserving C8 olefin production efficiency, resolving the contradiction between productivity and ease of manufacture.
3Adaptability or versatility
If 1-butene concentration is below thermodynamic equilibrium, then adaptability to low 1-butene streams is improved, but C8 olefin selectivity may be affected
Solution Approach 1:
The patent changes the conversion rate parameter to a specific range (5-40% by weight) and introduces a high recycle rate (≥100%) to maintain C8 olefin selectivity even when 1-butene concentration is below thermodynamic equilibrium. This allows the process to adapt to low 1-butene streams while preserving manufacturing precision for C8 olefin production.
Solution Approach 2:
The high recycle rate creates a feedback mechanism where unconverted butenes are recycled back to the reaction zone, maintaining adequate reactant concentration and ensuring consistent C8 olefin selectivity even when the feed stream has low 1-butene content. This feedback loop resolves the contradiction between adaptability and manufacturing precision.
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 achieves high selectivity for C8 olefins (>80% by weight) and a low isoindex, making it suitable for plasticizer production, while being adaptable to C4 streams with low 1-butene content, thus improving the economic viability and raw material utilization.
Implementation Method 1
oligomerizing a portion of the butenes contained in the hydrocarbon mixture to C8 olefins and to C12 olefins by bringing the hydrocarbon mixture into contact with an oligomerization catalyst
Implementation Method 2
the conversion of butenes balanced directly via the first reaction zone is limited to a first limit value between 5 and 40 wt.-% lies
Data Source
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AI summary
The invention relates to an OCTOL process, which, because of the limitation of the reaction in individual oligomerization steps of the OCTOL process, is designed particularly for the processing of C4 feed mixtures having a low 1-butene content and which nevertheless provides a C8 product mixture having an iso index suitable for the production of plasticizer alcohols.