Propylene Oxide Purification Using Amine-Functionalized Resin

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Solution Overview

Problem

Current methods for purifying propylene oxide to achieve low aldehyde impurity levels are energy-intensive and costly, particularly when aiming for levels below 10 ppm, as they require significant energy input through distillation processes.

Innovation Solution

Contacting propylene oxide with an amine-functionalized ion exchange resin in the liquid phase to reduce aldehyde impurities from 25-100 ppm to 10 ppm or less, utilizing a macroporous polystyrene divinylbenzene cross-linked copolymer with amine groups, such as Lewatit® VP OC 1065, in a continuous process with controlled temperature and flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If distillation processes are used to reduce aldehyde impurity levels to 10 ppm or lower, then manufacturing precision is improved, but use of energy worsens significantly

Engineering Contradiction:
Improvealdehyde impurity levelVSAvoidenergy input
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent employs a macroporous polymeric adsorbent material with specific pore structure and surface chemistry to selectively adsorb aldehyde impurities from propylene oxide. The porous structure provides high surface area for impurity capture while allowing propylene oxide to pass through, achieving low aldehyde levels without energy-intensive distillation

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent replaces the mechanical/thermal distillation system with a chemical adsorption system. Instead of using heat and mass transfer through phase change, the invention uses selective chemical adsorption on a porous polymer material to remove aldehydes, substituting a low-energy chemical process for a high-energy mechanical separation process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If multiple stage distillation processes are used to purify propylene oxide, then manufacturing precision is improved, but device complexity worsens

Engineering Contradiction:
Improvealdehyde impurity levelVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the aldehyde impurity removal function from the complex multi-stage distillation system and concentrates it into a single adsorption step using a specifically designed polymeric adsorbent. This single-step extraction achieves the same purification effect that previously required multiple distillation stages

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fundamental separation mechanism from thermal distillation based on boiling point differences to adsorption based on chemical affinity and pore structure. This parameter change in the separation mechanism allows for simpler equipment and lower operating conditions while achieving equivalent or superior purification

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces aldehyde impurities to 10 ppm or less with lower energy requirements and production costs compared to traditional distillation methods, achieving exceptional purity while maintaining operational efficiency.

Implementation Method 1

contacting the propylene oxide in the liquid phase with an amine-functionalized ion exchange resin

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2552897B1Purification of propylene oxide
Publication Date: 2014.08.20 LYONDELL CHEMICAL TECHNOLOGY LP

AI summary

The invention is a method of purifying propylene oxide containing 25-100 ppm aldehyde impurities. The method comprises contacting the propylene oxide in the liquid phase with an amine-functionalized ion exchange resin, and recovering a purified propylene oxide product containing 10 ppm, or less, aldehydes.