Epsilon-Caprolactam Recovery Process Segmentation

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Solution Overview

Problem

Existing processes for recovering ε-caprolactam from extract water are inflexible in meeting varying purity requirements, leading to increased costs and energy consumption, as they struggle to remove highly volatile impurities and inefficiently handle different product quality demands.

Innovation Solution

An additional distillation step is introduced to separate highly volatile impurities, allowing for adaptable purity control and energy optimization by branching off intermediate product streams, which can be combined or used separately based on quality requirements, thereby optimizing energy consumption and product quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the existing recovery process (steps a-d) is used, then the process is simple and energy consumption is moderate, but highly volatile impurities cannot be removed and purity requirements cannot be sufficiently satisfied

Engineering Contradiction:
Improvepurity of recovered ε-caprolactamVSAvoidcomplexity of recovery process
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The recovery process is segmented into two distinct pathways: a simplified process (steps a-d) for cases where high purity is not critical, and an extended process (steps a-e) with an additional distillation step for cases requiring highest purity. This segmentation allows the system to adapt to different purity requirements without always incurring the complexity and energy cost of the full process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The process design allows dynamic selection between different operational modes based on purity requirements. The additional distillation step (step e) can be activated or deactivated depending on the specific purity needs, making the process flexible and adaptable rather than fixed and rigid.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the existing recovery process (steps a-d) is used, then the process operates efficiently for low purity requirements, but it cannot satisfy highest purity requirements and leads to increased costs

Engineering Contradiction:
Improveenergy efficiency of recovery processVSAvoidpurity of recovered ε-caprolactam
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The process allows changing the operational parameters by selectively activating or deactivating the additional distillation step (step e) based on the required purity level. When high purity is needed, the extra distillation is activated; when moderate purity suffices, it is deactivated, thereby optimizing energy efficiency while meeting purity requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of always performing the complete purification sequence, the process applies partial action by executing only the necessary steps (a-d) when high purity is not required, and adding step e only when needed. This avoids the excessive energy consumption of always performing the full purification process.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If the additional distillation step (step e) is always performed, then highest purity requirements are satisfied, but energy consumption increases and economic efficiency decreases

Engineering Contradiction:
Improvepurity of recovered ε-caprolactamVSAvoidenergy consumption of recovery process
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The process design enables dynamic adjustment of the purification level by selectively activating the additional distillation step (step e) only when highest purity requirements exist. This dynamic approach prevents unnecessary energy consumption when high purity is not required, optimizing the balance between purity and energy use.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The operational parameters of the recovery process are changed based on purity requirements. The system can switch between a standard mode (steps a-d) and an enhanced purification mode (steps a-e), allowing parameter optimization that reduces energy consumption while maintaining adequate purity levels for each application.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If the recovery process is optimized for high purity, then product quality is high, but the process cannot flexibly adapt to low purity requirements and vice versa

Engineering Contradiction:
Improvepurity of recovered ε-caprolactamVSAvoidflexibility to purity requirements
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The recovery process is divided into modular segments where the additional distillation step (step e) can be independently activated or deactivated. This segmentation provides flexibility to adapt the process to different purity requirements, allowing the system to serve both high-purity and moderate-purity applications with a single integrated process design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The recovery process is designed with multi-functionality, capable of operating in two modes: standard purification (steps a-d) for moderate purity requirements and enhanced purification (steps a-e) for highest purity requirements. This universal design allows the same process infrastructure to adapt to varying purity needs without requiring separate dedicated processes.

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 process achieves flexible purity control and reduced energy consumption by separating highly volatile impurities and utilizing intermediate product streams, enabling the production of specification-compliant products with optimized energy efficiency.

Implementation Method 1

By a single- or multistage distillation, the extract water is concentrated by separation of water

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 2

the concentrated extract water is separated by distillation into a vaporous ε-caprolactam-water phase and a liquid oligomer-ε-caprolactam phase

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

into the liquid oligomer-ε-caprolactam phase steam is introduced in the presence of a catalyst, wherein the oligomers are hydrolytically depolymerized to ε-caprolactam, and ε-caprolactam is stripped out of the phase by the steam

Methodology Applied
Scientific EffectSteam stripping: Sparging

Implementation Method 4

into the liquid oligomer-ε-caprolactam phase steam is introduced in the presence of a catalyst, wherein the oligomers are hydrolytically depolymerized to ε-caprolactam

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP3019471B1Process for the recovery of epsilon-caprolactam from extract water
Publication Date: 2018.06.27 TECHNIP ZIMMER
  • EP3019471B1 patent drawingFigure 1

AI summary

A process for the recovery of ε-caprolactam from extract water of polycaprolactam obtained by hydrolytic polymerization, wherein the extract water is concentrated, subsequently contained oligomers are depolymerized, non-depolymerizable impurities are separated, water and low-boiling impurities are removed, wherein for adjusting the purity of the recovered ε-caprolactam and the energy consumption used for the process a part of the product is removed from the process as intermediate products.