Cyclohexyl Hydroperoxide Extraction Column Segmentation

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Solution Overview

Problem

The existing processes for producing cyclohexyl hydroperoxide through the oxidation of cyclohexane suffer from poor selectivity in water extraction, leading to partial extraction of non-water-soluble oxidized products into the aqueous phase, which reduces yield and process economy.

Innovation Solution

A process involving the oxidation of cyclohexane with molecular oxygen, followed by countercurrent liquid-liquid extraction in a column where cyclohexane is fed downstream relative to the water circulation direction, significantly reducing the concentration of cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide in the aqueous phase, and incorporating an initial aqueous washing step to remove metal impurities from fresh cyclohexane before oxidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water extraction is used to separate oxidized products from the reaction medium, then water-soluble non-olonogenic products are removed, but water-insoluble olonogenic products (cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide) are partially extracted into the aqueous phase, reducing yield and process economy

Engineering Contradiction:
Improveselectivity of water extractionVSAvoidloss of olonogenic products
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The extraction column is divided into multiple sections with different feed injection points. The reaction medium is introduced at an intermediate level rather than the top, creating distinct zones: an upper section where water extracts non-olonogenic products, and a lower section where fresh cyclohexane co-currently extracts olonogenic products from the aqueous phase, preventing their loss in the wastewater stream

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Fresh cyclohexane acts as an intermediary substance introduced into the lower section of the extraction column. It performs a dual function: serves as the solvent for the oxidation reaction and acts as a co-extractant in the lower section to retrieve olonogenic products from the aqueous phase, thereby reducing their loss in wastewater

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If fresh cyclohexane is introduced into the oxidation reactors, then the oxidation reaction proceeds, but metal impurities in the fresh cyclohexane can catalyze unwanted side reactions or interfere with the process

Engineering Contradiction:
Improveoxidation reaction rateVSAvoidmetal impurity interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Aqueous washing is performed on the fresh cyclohexane before it is introduced into the oxidation reactors. This preliminary treatment removes metal impurities from the hydrocarbon feed, preventing them from catalyzing unwanted side reactions or interfering with the oxidation process while maintaining productivity

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If the reaction medium is washed with water to remove oxidized products, then non-olonogenic products are extracted, but the extraction is not perfectly selective and olonogenic products are partially lost

Engineering Contradiction:
Improvepurity of separationVSAvoidloss of cyclohexyl hydroperoxide
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The extraction column is segmented into functional zones with different feed introduction points. The reaction medium enters at an intermediate level, creating an upper extraction zone for non-olonogenic products and a lower zone where fresh cyclohexane recovers olonogenic products, thereby achieving high separation precision while minimizing product loss

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of discarding the aqueous phase after a single extraction step, the system recovers olonogenic products from the aqueous phase using fresh cyclohexane in the lower section of the column, converting what would be waste into a valuable product stream

Inventive Principle:
Principle #34Discarding and recovering

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 effectively reduces the concentration of cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide in the aqueous effluent to a few hundred ppm, enhancing process economy and reducing the need for aqueous washing capacity, while minimizing product losses and metal impurity-related issues.

Implementation Method 1

oxidation of cyclohexane with molecular oxygen

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

washing by water from the oxidation reaction medium recovered after the separation of at least part of the non-oxidized hydrocarbon, to extract the oxidized products formed during the oxidation and soluble in water

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

Data Source

PatentEP2526087B1Method for producing alkyl hydroperoxide
Publication Date: 2015.04.29 RHODIA OPERATIONS SAS

AI summary

The invention relates to a method for preparing an alkyl hydroperoxide obtained by the oxidation of a saturated hydrocarbon using oxygen, preferably of a saturated cyclic hydrocarbon. The invention more particularly relates to the production of cyclohexyl hydroperoxide obtained by oxidizing cyclohexane with molecular oxygen or a gas containing molecular oxygen preferably in the absence of a catalyst.