Bisphenol A Process Using Sulfur Cocatalyst to Tolerate Alpha-Methylstyrene

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Solution Overview

Problem

Current processes for producing bisphenol A are hindered by catalyst poisoning from alpha-methylstyrene impurities, leading to increased costs and reduced flexibility in raw material selection due to the need for low impurity levels and extensive purification, which affects catalyst performance and process efficiency.

Innovation Solution

A catalyst system comprising an ion exchange resin and a sulfur-containing cocatalyst, where the cocatalyst is not chemically bound to the resin, is used to condense phenol and acetone, allowing higher concentrations of alpha-methylstyrene without catalyst poisoning, enabling the use of cheaper raw phenol and reducing the need for extensive purification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If extensive purification of raw phenol is performed to remove alpha-methylstyrene impurities, then catalyst performance is maintained, but production costs increase and process flexibility decreases

Engineering Contradiction:
Improvecatalyst performanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent converts the harmful effect of alpha-methylstyrene impurities into a beneficial outcome by using a sulfur-containing cocatalyst system that not only tolerates but actually benefits from the presence of these impurities. The cocatalyst prevents catalyst poisoning while maintaining high conversion rates, thereby eliminating the need for expensive purification steps and allowing the use of cheaper, less purified raw phenol.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If extensive purification of raw phenol is performed to remove alpha-methylstyrene impurities, then catalyst performance is maintained, but process flexibility decreases

Engineering Contradiction:
Improvecatalyst performanceVSAvoidraw material selection flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The sulfur-containing cocatalyst system transforms the previously harmful alpha-methylstyrene impurity into a tolerable condition, enabling the process to accept a broader range of raw phenol qualities from different suppliers without purification. This increases adaptability and versatility in raw material selection while maintaining catalyst performance.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If sulfur-containing cocatalyst is used to tolerate alpha-methylstyrene impurities, then production costs decrease and process flexibility increases, but catalyst deactivation over time occurs

Engineering Contradiction:
Improveproduction costVSAvoidcatalyst dwell time
Core Design Contradiction:
Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by pre-regenerating the ion exchange resin catalyst in situ within the reaction system. The resin is periodically regenerated by treating it with a strong acid solution (such as sulfuric acid or hydrochloric acid) to restore its sulfonic acid groups, thereby extending the catalyst's operational life and maintaining high conversion rates over extended periods without requiring complete catalyst replacement.

Inventive Principle:
Principle #10Preliminary action

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 results in a more economical and flexible process with reduced energy consumption, allowing for the use of phenol with higher alpha-methylstyrene concentrations, thereby lowering production costs and environmental impact while maintaining catalyst performance.

Implementation Method 1

BPA is produced by reacting phenol with acetone in the presence of an acid catalyst to give the bisphenol

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

the reaction of phenol with acetone can be performed in the presence of suitable co-catalyst

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentUS20240076256A1Process for preparing bisphenol a (BPA) in the presence of alpha-methylstyrene
Publication Date: 2024.03.07 COVESTRO DEUTSCHLAND AG

AI summary

The present invention relates to a process for preparing bisphenol A in the presence of alpha-methylstyrene without poisoning the catalyst system comprising an ion exchange resin catalyst and a sulfur containing cocatalyst. Moreover, the present invention provides a process for preparing polycarbonate.