Polyether Carbonate Polyol Preparation via DMC Catalyst Washing
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Solution Overview
Problem
Existing processes for preparing polyether carbonate polyols using double metal cyanide catalysts do not achieve high carbon dioxide incorporation efficiently, especially under mild reaction conditions, and often result in a high ratio of cyclic carbonate to linear product.
Innovation Solution
A process involving the synthesis of a double metal cyanide catalyst using an organic complexing agent and a polyether polyol ligand, followed by washing with an aqueous solution containing only polyether polyol, which enhances the catalyst's activity and selectivity for carbon dioxide incorporation, allowing for higher CO2 content in polyether carbonate polyols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing DMC catalyst preparation processes are used, then the catalyst can be obtained, but the carbon dioxide incorporation efficiency is low and cyclic carbonate ratio is high
Solution Approach 1:
The patent changes the chemical composition parameters of the washing solution used in catalyst preparation. Specifically, it uses an aqueous solution containing only polyether polyol (without other organic complexing agents like TBA), which fundamentally alters the catalyst's chemical properties to achieve high CO2 incorporation efficiency and low cyclic carbonate formation.
Solution Approach 2:
The patent applies preliminary action by modifying the catalyst preparation process before the actual copolymerization reaction. The washing step with the specific aqueous polyether polyol solution is performed in advance to pre-condition the catalyst, ensuring it has the optimal properties for high CO2 incorporation and low cyclic carbonate formation during the subsequent reaction.
2Use of energy by moving object
If mild reaction conditions are used, then energy consumption is reduced, but carbon dioxide incorporation content decreases
Solution Approach 1:
The patent changes the catalyst's chemical composition parameters through the specific washing process, which enables the catalyst to maintain high CO2 incorporation efficiency even under mild reaction conditions (lower temperature, pressure, and longer reaction time), thus reducing energy consumption while preserving product quality.
Solution Approach 2:
The patent creates a modified version of the conventional DMC catalyst through the washing process, which copies the essential catalytic function but with enhanced properties for CO2 incorporation. This 'copied' catalyst behavior allows mild reaction conditions to be effective.
3Ease of manufacture
If conventional washing procedures are used, then catalyst preparation is simple, but catalyst activity and selectivity for CO2 incorporation are insufficient
Solution Approach 1:
The patent modifies the washing solution composition parameter by eliminating organic complexing agents and using only aqueous polyether polyol. This simple parameter change maintains ease of manufacture while dramatically improving catalyst activity and selectivity for CO2 incorporation.
Solution Approach 2:
The patent applies the extraction principle by removing other organic complexing agents (like TBA) from the washing solution, keeping only the polyether polyol component. This extraction of unnecessary components simplifies the process while enhancing catalyst performance for CO2 incorporation.
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 a higher content of incorporated carbon dioxide in polyether carbonate polyols compared to previous methods, with a lower ratio of cyclic carbonate to linear product, even under mild reaction conditions.
Implementation Method 1
double metal cyanide (DMC) catalysts which are highly active in the polymerization of alkylene oxides to obtain polyols... allows the incorporation of high contents of CO2 when the alkylene oxides are copolymerized with carbon dioxide
Implementation Method 2
synthesizing a solid double metal cyanide catalyst in the presence of an organic complexing agent and a polyether polyol ligand
Implementation Method 3
first washing the catalyst obtained in step a) with an aqueous solution comprising 90-100% by weight of water and 0-10% by weight of a polyether polyol ligand
Data Source
AI summary
The present invention relates to a process for the preparation of polyether carbonate polyols in the presence of a double metal cyanide catalysts that can be obtained by a process comprising (a) synthesizing a solid double metal cyanide catalyst in the presence of an organic complexing agent and a polyether polyol ligand; and (b) first washing the catalyst obtained in step a) with an aqueous solution comprising 90-100% by weight of water and 0-10% by weight of a polyether polyol ligand, to form a slurry, wherein the aqueous solution does not contain any organic complexing agent other than the polyether polyol ligand.