Stage-Heated Distillation Column for High-Purity Alpha Olefins
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional separation processes struggle to achieve high purity levels of linear alpha olefins due to the wide range of boiling points in reactor effluents, leading to inefficient distillation column design and operation.
Innovation Solution
A stage-heated distillation column is used, where heat is added directly to specific stages of the column, and an aliphatic paraffin hydrocarbon solvent is introduced in the rectifying section to absorb linear alpha olefins, reducing the need for a conventional overhead condenser and enhancing column efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional distillation column is used to separate components with widely varying boiling points, then separation of linear alpha olefins can be achieved, but the temperature changes dramatically in the stripping section leading to large sensible heat duty and difficult efficient design
Solution Approach 1:
The distillation column is divided into multiple heating zones along the stripping section, with each zone independently controllable. This segmentation allows localized temperature control to manage the large boiling point differences between components, reducing the overall sensible heat duty while maintaining separation efficiency.
Solution Approach 2:
The system employs dynamic temperature control in the stripping section through multiple heating zones that can be independently adjusted. This dynamic control allows the column to adapt to varying operating conditions and maintain optimal separation performance without requiring excessive column diameter or complex structural modifications.
2Manufacturing precision
If conventional overhead condenser with reflux is used, then high purity linear alpha olefin can be obtained, but expensive refrigeration system is required
Solution Approach 1:
The invention extracts and removes the need for an overhead condenser with reflux by implementing an alternative separation mechanism in the stripping section. Multiple heating zones enable direct vaporization and separation of components without requiring the expensive refrigeration system that would be needed for conventional overhead condensation.
3Productivity
If column diameter is increased in the stripping section to account for steep liquid/vapor flow gradient, then separation efficiency can be maintained, but device complexity and cost increase
Solution Approach 1:
The stripping section is segmented into multiple heating zones with independent temperature control. This segmentation allows the column to maintain a more uniform liquid/vapor flow profile by distributing heat addition throughout the section, thereby reducing the need for large diameter variations and simplifying the overall column design.
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 allows for stable and efficient distillation column operation with minimal diameter changes, achieving high purity linear alpha olefins without the need for expensive refrigeration systems and complex column designs.
Implementation Method 1
an aliphatic paraffin hydrocarbon solvent is added to the rectifying section of the distillation column to absorb linear alpha olefin
Implementation Method 2
heat is added directly to certain stages of the column so that all sensible heat needed in the column is not required from the reboiler
Implementation Method 3
the effluent from the reactor used to produce the linear alpha olefins is directed to one or more distillation columns to separate the various fractions of linear alpha olefins
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The disclosure provides a method of purifying a linear alpha olefin product that includes feeding a linear alpha olefin feed stream comprising the linear alpha olefin product and ethylene into a feed stage of a distillation column, the distillation column having a plurality of stacked stages positioned between an overhead outlet and a bottoms reboiler including a stripping section and a rectifying section; feeding an aliphatic paraffin hydrocarbon solvent to the rectifying section of the distillation column to absorb linear alpha olefin; adding heat to at least one of said plurality of stacked stages in the stripping section of the distillation column between the feed stage and the bottoms reboiler; withdrawing an overhead stream comprising ethylene from the overhead outlet; and withdrawing a bottoms stream from the distillation column comprising the linear alpha olefin product.