NMEDA Separation from EDA Mixtures in Single-Column Rectification
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Solution Overview
Problem
Existing processes for separating N-methylethylenediamine (NMEDA) from ethylenediamine (EDA) mixtures are inefficient, requiring multiple columns and significant equipment, which increases investment costs and does not meet the market demand for high-purity EDA with low NMEDA content.
Innovation Solution
A process that operates a rectification column at a top pressure of 5.0 to 7.5 bar to efficiently separate NMEDA and water from EDA in a single column, reducing the number of required columns and equipment size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple rectification columns are used to separate NMEDA from EDA mixtures, then the purity of EDA can be improved, but the device complexity and investment costs increase
Solution Approach 1:
The patent combines multiple separation functions into a single rectification column by operating at a specific pressure range (5-7.5 bar). This single column simultaneously separates NMEDA from EDA and removes water, achieving the same purification effect that would traditionally require multiple columns, thereby reducing device complexity and investment costs while maintaining high EDA purity
Solution Approach 2:
The patent changes the operating pressure parameter to a specific range (5-7.5 bar) to optimize the separation process. This pressure adjustment modifies the vapor-liquid equilibrium relationships, enabling efficient separation of NMEDA and water from EDA in a single column, thus resolving the contradiction between purity requirements and device complexity
2Manufacturing precision
If multiple rectification columns are used to separate NMEDA from EDA mixtures, then the separation efficiency can be improved, but the productivity decreases due to increased processing time and complexity
Solution Approach 1:
By merging multiple separation stages into one rectification column operating at 5-7.5 bar, the patent eliminates the need for sequential processing through multiple columns. This integration maintains high separation efficiency for NMEDA removal while simultaneously improving productivity by reducing the overall processing time and operational complexity
Solution Approach 2:
The single-column design enables continuous operation for both NMEDA separation and water removal simultaneously. The useful action of purification continues without interruption through multiple stages within one column, maintaining high separation efficiency while improving productivity compared to discrete multi-column operations
3Manufacturing precision
If the rectification column operates at lower pressure to separate NMEDA, then the purity of EDA can be improved, but the equipment size and investment costs increase
Solution Approach 1:
The patent optimizes the pressure parameter to a moderate range (5-7.5 bar) rather than using very low pressures. This pressure optimization achieves the necessary vapor-liquid equilibrium for high-purity EDA separation while avoiding the excessively large column sizes and high investment costs that would result from operating at much lower pressures
4Manufacturing precision
If more theoretical plates are added to the rectification column to improve separation, then the purity of EDA can be improved, but the device complexity and cost increase
Solution Approach 1:
The patent uses pressure optimization (5-7.5 bar) to enhance separation efficiency, which allows achieving high EDA purity with a moderate number of theoretical plates. The pressure change modifies the relative volatility of components, improving separation effectiveness without requiring an excessive number of plates, thus avoiding increased device complexity and cost
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-purity EDA with NMEDA content below 1000 ppm by weight, reducing investment costs and optimizing the separation process.
Implementation Method 1
a mixture consisting of ethylenediamine, water and one or more alkylethyleneamines is subjected to such conditions that an azeotrope is formed between the water and the alkylethyleneamines, which is separated from the remaining composition
Implementation Method 2
an azeotrope is formed between the water and the alkylethyleneamines, which is separated from the remaining composition
Data Source
AI summary
A process for producing EDA from a mixture comprising water (H2O), ethylenediamine (EDA) and N-methylethylenediamine (NMEDA) by feeding the mixture into a rectification column, wherein the rectification column is operated at the top pressure in the range of 5.0 to 7.5 bar.