Diaryl Carbonate Production Catalyst Stability

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Solution Overview

Problem

The production of diaryl carbonates is hindered by low reaction efficiency due to equilibrium bias in transesterification and disproportionation reactions, catalyst deactivation, and apparatus clogging, leading to fluctuations in productivity and increased costs for overhaul and purification.

Innovation Solution

A method involving a metal-containing catalyst composition with controlled by-product ratios and recycling of high boiling components to maintain catalyst stability and prevent clogging, utilizing a titanium-containing catalyst with specific aryloxytitanium composition and controlled reaction conditions to enhance diaryl carbonate production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If transesterification and disproportionation reactions are used to produce diaryl carbonate, then diaryl carbonate can be obtained through established chemical pathways, but the reaction efficiency is low due to equilibrium bias and slow reaction rates

Engineering Contradiction:
Improvereaction efficiencyVSAvoidequilibrium stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by optimizing reaction conditions including temperature (150-250°C), pressure control, and catalyst concentration to shift the equilibrium position and accelerate reaction rates. The continuous removal of by-products through distillation also dynamically changes reaction parameters to favor product formation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts by-products (alcohols and water) from the reaction system through continuous distillation and separation processes. This removal of products from the equilibrium system drives the reaction forward according to Le Chatelier's principle, improving overall reaction efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If catalysts are used to improve reaction rate, then productivity increases, but catalyst deactivation occurs leading to fluctuating productivity

Engineering Contradiction:
Improvereaction rateVSAvoidcatalyst stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements feedback control by continuously monitoring catalyst activity and adjusting operational parameters accordingly. When catalyst deactivation is detected through productivity fluctuations, the system responds by optimizing reaction conditions or replenishing catalyst to maintain stable performance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by pre-treating catalysts to enhance their stability before use, and by designing the reaction system to prevent conditions that would accelerate deactivation. The catalyst is prepared and activated under controlled conditions prior to the main reaction process.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If high temperature conditions are used for purification, then separation efficiency improves, but catalyst function decreases due to pyrolysis

Engineering Contradiction:
Improvepurification efficiencyVSAvoidcatalyst activity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent segments the thermal processing into distinct stages: mild heating for reaction (150-250°C) and controlled distillation for purification. This segmentation allows separation of catalyst-sensitive steps from high-temperature purification steps, preventing catalyst exposure to pyrolytic conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses an intermediary approach by performing purification on reaction mixtures that have been cooled and stabilized, rather than directly heating catalyst-containing mixtures to high temperatures. The separation process uses temperature gradients and phase differences without subjecting the catalyst to destructive temperatures.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If continuous production methods are implemented, then productivity increases, but apparatus clogging occurs requiring overhauls

Engineering Contradiction:
Improvecontinuous outputVSAvoidapparatus maintenance
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent implements periodic action by designing the continuous production system with regular maintenance intervals and periodic flushing procedures. The system operates continuously for optimized production periods, then undergoes scheduled maintenance to prevent clogging accumulation, balancing productivity with ease of manufacture.

Inventive Principle:
Principle #19Periodic 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 method stabilizes diaryl carbonate production over long periods with high productivity, suppresses catalyst deactivation, and prevents apparatus clogging, ensuring efficient and continuous production.

Implementation Method 1

a method for producing a diaryl carbonate, using a metal-containing catalyst composition as a reaction catalyst

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

subjecting the alkylaryl carbonate obtained in the step (1) to a transesterification or disproportionation reaction so as to obtain a reaction product including the diaryl carbonate

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

a step (3) of distilling the reaction product obtained in the step (2) to separate the reaction product into a low boiling component including the diaryl carbonate and a high boiling component including the reaction catalyst

Methodology Applied
Scientific EffectDistillation: Distillation

Data Source

PatentEP2540697B1Method for producing diaryl carbonate
Publication Date: 2022.04.20 ASAHI KASEI KOGYO KABUSHIKI KAISHA
  • EP2540697B1 patent drawingFigure 1
  • EP2540697B1 patent drawingFigure 2
  • EP2540697B1 patent drawingFigure 3

AI summary

The present invention provides a method for continuously producing a diaryl carbonate stably for a long time with high productivity. The method for producing a diaryl carbonate according to the present invention comprises a step (1) of obtaining an alkylaryl carbonate; a step (2) of obtaining a reaction product from the alkylaryl carbonate; a step (3) of separating the diaryl carbonate and a high boiling component from the reaction product; and a step (4) of recycling the high boiling component into the steps (1) and/or (2), wherein the high boiling component recycled in the step (4) includes a particular compound, and the particular compound satisfies a particular condition.