Rectification Column Separation of NMEDA from EDA Mixtures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for purifying ethylenediamine (EDA) to achieve low N-methylethylenediamine (NMEDA) content are energy-intensive and inefficient, failing to meet the required purity standards of 99.5% EDA with NMEDA content below 1000 ppm by weight.
Innovation Solution
A process involving rectification in a column with a bottom temperature of 155° C. or less, using a mixture with sufficient water to form a high-boiling azeotrope with EDA, and comprising 50 to 140 theoretical plates, effectively separates NMEDA from EDA, reducing energy demand and achieving the desired purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional rectification processes are used to purify EDA, then NMEDA content can be reduced, but energy consumption increases significantly
Solution Approach 1:
The patent changes the operating parameters of the rectification column, specifically maintaining a bottom temperature of 155°C or less and operating at reduced pressure (1.01-2.12 bar), which optimizes the separation efficiency while minimizing energy consumption compared to conventional high-temperature distillation processes
Solution Approach 2:
The patent introduces water as an intermediary substance that forms a high-boiling azeotrope with NMEDA, allowing the impurity to be selectively removed in the distillate phase while EDA remains in the bottoms, achieving purification with lower energy input
2Manufacturing precision
If rectification is conducted at higher temperatures to improve separation efficiency, then NMEDA removal is enhanced, but energy consumption increases
Solution Approach 1:
The patent optimizes the bottom temperature parameter to 155°C or less, which is sufficiently high to achieve effective separation of NMEDA from EDA but low enough to minimize energy consumption and avoid excessive vapor generation that would increase operational costs
3Manufacturing precision
If the rectification column has more theoretical plates to improve separation, then purification efficiency increases, but device complexity and capital cost increase
Solution Approach 1:
The patent specifies an optimal range of 50 to 140 theoretical plates, which provides sufficient separation stages to achieve the required purity (NMEDA content below 1000 ppm) while avoiding excessive column height and associated capital costs that would result from using more plates
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 method significantly reduces the NMEDA content in EDA, achieving the specified purity levels while minimizing energy consumption, making the process economically favorable and suitable for industrial applications.
Implementation Method 1
a process for separating N-methylethylenediamine from EDA-containing mixtures by rectification in a rectification column
Implementation Method 2
the mixture comprises at least the amount of water as required for the formation of a high-boiling azeotrope of EDA and water
Data Source
AI summary
The present invention relates to a process for removing NMEDA from a mixture comprising water (H2O), ethylenediamine (EDA) and N-methylethylenediamine (NMEDA) by a rectification in a rectification column (NMEDA removal), wherein the rectification is conducted at a bottom temperature TB of 155° C. or less and the mixture comprises at least the amount of water as required for the formation of a high-boiling azeotrope of EDA and water at the corresponding bottom temperature.