1,3-Butadiene Purification via Dividing Wall Column and Extractive Distillation
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Solution Overview
Problem
The recovery of pure 1,3-butadiene from C4 cuts is complex due to the small differences in relative volatilities of components, leading to high costs and safety risks from the formation of popcorn polymers, which require frequent and costly maintenance to prevent system damage.
Innovation Solution
A process involving the separation of low and high boiler fractions from crude C4 cuts by distillation, followed by extractive distillation with a selective solvent, specifically using a dividing wall column to achieve high purity of 1,3-butadiene while reducing the content of impurities like propyne, 1,2-butadiene, and C5+ hydrocarbons, and removing reactive oligomers and polymers to prevent accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If extractive distillation is used to separate 1,3-butadiene from C4 cuts, then separation efficiency is improved, but system complexity and maintenance costs increase due to popcorn polymer formation
Solution Approach 1:
The patent applies preliminary action by removing reactive components (propyne, 1,2-butadiene, C5+ hydrocarbons) from the C4 cut before the extractive distillation process. This pre-treatment prevents these components from forming popcorn polymers during the main separation process, thereby reducing maintenance requirements and system complexity while maintaining separation efficiency.
2Manufacturing precision
If multiple distillation steps are performed to achieve high purity 1,3-butadiene, then product purity is improved, but processing time and energy consumption increase
Solution Approach 1:
The patent applies the extraction principle by removing specific impurity components (propyne, 1,2-butadiene, C5+ hydrocarbons) from the C4 cut before the main extractive distillation process. This pre-extraction of problematic components reduces the burden on subsequent distillation steps, allowing high purity 1,3-butadiene to be achieved with fewer and more efficient distillation operations, thereby reducing processing time and energy consumption.
3Reliability
If frequent maintenance is performed to prevent popcorn polymer accumulation, then system reliability is improved, but productivity decreases
Solution Approach 1:
The patent applies preliminary action by removing reactive components that form popcorn polymers before the extractive distillation process. This pre-treatment significantly reduces polymer accumulation in the system, extending maintenance intervals and reducing the frequency of shutdowns for cleaning and maintenance, thereby improving productivity while maintaining system reliability.
4Manufacturing precision
If selective solvent is used to increase relative volatility differences, then separation effectiveness is improved, but operating costs increase due to solvent loading and regeneration requirements
Solution Approach 1:
The patent applies the extraction principle by removing components with high solvent affinity (propyne, 1,2-butadiene, C5+ hydrocarbons) from the C4 cut before the extractive distillation process. This pre-removal reduces the amount of impurities that would otherwise be loaded onto the selective solvent during the main separation process, thereby reducing solvent regeneration requirements and associated energy costs while maintaining separation effectiveness.
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 process effectively reduces the content of impurities below specification limits, minimizing the formation of popcorn polymers and associated risks, thereby simplifying the system, reducing maintenance costs, and achieving high-purity 1,3-butadiene production with improved safety and efficiency.
Implementation Method 1
a low boiler fraction and a high boiler fraction are separated from a crude C 4 cut by distillation
Implementation Method 2
subjecting the purified C 4 cut to at least one extractive distillation with a selective solvent
Data Source
Figure 1
AI summary
The invention relates to a method for obtaining pure 1,3-butadiene from a raw C4 cut, said 1,3-butadiene having a specified maximum content of at least one low-boiling fraction and a specified maximum content of 1,2-butadiene, in each case based on 1,3-butadiene, wherein (a) a light-boiling fraction and a high-boiling fraction are separated from the raw C4 cut by distillation, a purified C4 cut being obtained, the content of the at least one low-boiling fraction of which is equal to or is less than the specified maximum content of the at least one low-boiling fraction, based on 1,3-butadiene, and the content of 1,2-butadiene of which is equal to or less than the specified maximum content of 1,2-butadiene, based on 1,3-butadiene, and (b) the purified C4 cut undergoes at least one extractive distillation using a selective solvent, wherein at least one butane- and butene-containing fraction and a pure 1,3-butadiene fraction are obtained. The method renders a pure distillation column unnecessary.