HMDA Extraction and Vacuum Distillation for Energy-Efficient Separation

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Solution Overview

Problem

Existing industrial methods for separating hexamethylene diamine (HMDA) from an aqueous solution obtained from microbial fermentation processes are energy-inefficient.

Innovation Solution

A method involving extraction of HMDA with a monovalent alcohol having 4 to 8 carbon atoms, followed by distillation of the HMDA-containing alcoholic phase at a pressure of 1-1000 mbar, using a single distillation column, to separate HMDA from the alcohol.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If distillation is performed at conventional pressure to separate HMDA from aqueous solution, then separation is achieved, but energy consumption is high

Engineering Contradiction:
Improveenergy consumptionVSAvoidseparation efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent applies parameter changes by performing distillation at reduced pressure (1-1000 mbar) instead of conventional atmospheric pressure. This pressure parameter change lowers the boiling point of HMDA and the extractant, enabling separation at lower temperatures and significantly reducing energy consumption while maintaining effective separation efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions by employing vacuum distillation where HMDA transitions from liquid to vapor phase at reduced pressure and temperature, then condenses back to liquid. This phase transition mechanism at lower energy input levels enables energy-efficient separation of HMDA from the aqueous fermentation broth.

Inventive Principle:
Principle #36Phase transitions

2Manufacturing precision

If multiple distillation columns are used to concentrate aqueous raw product or isolate HMDA, then separation purity is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improveseparation purityVSAvoidnumber of distillation columns
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple distillation operations into a single distillation column by performing vacuum distillation of the HMDA-containing alcoholic phase. This combined approach achieves both concentration of the aqueous raw product and isolation of pure HMDA in one integrated unit operation, reducing device complexity from multiple columns to a single column while maintaining separation purity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single distillation column performs multiple functions simultaneously: it concentrates the aqueous phase, separates HMDA from the extractant, and purifies the final product. This multi-functional approach replaces what would traditionally require multiple specialized distillation columns, reducing overall device complexity while achieving the same separation purity goals.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The method achieves improved energy efficiency in the separation process by optimizing the distillation pressure, reducing energy consumption and enhancing the separation efficiency of HMDA from the aqueous solution.

Implementation Method 1

extracting the HMDA-containing aqueous solution with a monovalent alcohol having 4 to 8 carbon atoms

Methodology Applied
Scientific EffectLiquid-liquid extraction: Liquid-Liquid Extraction

Implementation Method 2

distilling the HMDA-containing alcoholic phase at a pressure of 1-1000 mbar and separating the HMDA from the monovalent alcohol

Methodology Applied
Scientific EffectDistillation: Distillation

Data Source

PatentEP4685134A1Method for separating hexamethylene diamine from an aqueous solution obtained from a microbial fermentation process
Publication Date: 2026.01.28 COVESTRO AG
  • EP4685134A1 patent drawingFigure 1
  • EP4685134A1 patent drawingFigure 2~3
  • EP4685134A1 patent drawingFigure 4~5

AI summary

The present invention provides a method for separating hexamethylene diamine (HMDA) from an aqueous solution, comprising the steps: a) providing an HMDA-containing aqueous solution, wherein said aqueous solution is a fermentation broth, b) extracting the HMDA-containing aqueous solution with a monovalent alcohol having 4 to 8 carbon atoms, c) obtaining an HMDA-containing alcoholic phase, and d) distilling the HMDA-containing alcoholic phase at a pressure of 1-1000 mbar and separating the HMDA from the monovalent alcohol.