Sidestream Distillation of Unsaturated Anhydrides Without Repurification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for producing unsaturated carboxylic anhydrides require additional purification steps to separate the target product from high-boiling secondary components and risk polymerization, leading to impurities and reduced purity.
Innovation Solution
The process involves discharging unsaturated carboxylic anhydride in gaseous form from a sidestream and condensing it in a cooled liquid circulating stream, eliminating the need for further purification steps and preventing polymerization by using a polymerization inhibitor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If further purification and distillation steps are used to separate the target product from high-boiling secondary components, then the purity of the unsaturated carboxylic anhydride is improved, but the process complexity and the risk of polymerization increase
Solution Approach 1:
The invention extracts and removes high-boiling secondary components (including process stabilizers) from the reaction mixture through a single distillation step, obtaining the unsaturated carboxylic anhydride in high purity form at a sidestream between the middle and lower regions of the rectification column, thereby eliminating the need for multiple subsequent purification steps
Solution Approach 2:
The invention changes the operating parameters of the distillation process, specifically operating at elevated temperatures (180-220°C) and utilizing the specific boiling point differences between the unsaturated carboxylic anhydride and high-boiling components, allowing direct obtention of high-purity product in a single step
2Manufacturing precision
If multiple purification steps are performed to achieve high purity, then the purity of the product is improved, but the time required for the process increases
Solution Approach 1:
The invention combines the separation of high-boiling components and the obtention of high-purity unsaturated carboxylic anhydride into a single integrated distillation process, where the product is obtained at a sidestream between the middle and lower regions of the rectification column, eliminating the need for sequential purification steps and significantly reducing process time
3Ease of manufacture
If the unsaturated carboxylic anhydride is obtained in liquid form from the bottom of the rectification column, then the collection process is simplified, but the purity is reduced due to contamination with high-boiling components
Solution Approach 1:
The invention segments the rectification column into different functional zones, with the unsaturated carboxylic anhydride being obtained at a sidestream between the middle and lower regions, separating it from the high-boiling components that continue to the bottom of the column, thus achieving both high purity and efficient collection
Solution Approach 2:
The invention uses an intermediary sidestream take-off point in the rectification column that acts as a mediator between the vapor phase containing the unsaturated carboxylic anhydride and the liquid phase containing high-boiling components, allowing selective withdrawal of the pure product while leaving contaminants in the bottom stream
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
Achieves high-purity unsaturated carboxylic anhydride production without additional purification steps and polymerization, ensuring the product's stability and purity.
Implementation Method 1
the unsaturated carboxylic anhydride is discharged in gaseous form from a sidestream take-off and is condensed in an atomized liquid circulating stream of this unsaturated carboxylic anhydride
Implementation Method 2
during distillative purification, the unsaturated carboxylic anhydride is discharged in gaseous form by side take-off
Data Source
AI summary
The invention relates to a process for distillative removal of a unsaturated carboxylic anhydride of the general formula (I) R—C(O)—O—C—(O)—R in which R is an unsaturated organic radical having 2 to 12 carbon atoms, wherein said unsaturated carboxylic anhydride is discharged in gaseous form from a sidestream take-off and is condensed in an atomized liquid circulating stream of said unsaturated carboxylic anhydride.