Recycle Light Phase to Break Emulsion Rag in Extraction
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Solution Overview
Problem
The recovery of diphosphite-containing compounds from hydrocyanation reaction product mixtures is hindered by the formation of an interfacial rag layer in multistage countercurrent liquid-liquid extractors, which inhibits phase separation and catalyst extraction efficiency.
Innovation Solution
A process involving a multistage countercurrent liquid-liquid extractor with a recycling mechanism, where a portion of the light phase is recycled back to the mixing section to enhance settling and reduce rag layer formation, using an aliphatic or cycloaliphatic hydrocarbon solvent and optionally a Lewis base to improve extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If liquid-liquid extraction is performed in a multistage countercurrent extractor to recover diphosphite-containing compounds, then extraction efficiency is improved, but an interfacial rag layer forms that inhibits phase separation and halts the process
Solution Approach 1:
The patent introduces an intermediary substance (rafficinate from a previous stage or fresh solvent) to interact with the rag layer at the interface. This intermediary displaces or dissolves the rag-forming compounds, allowing phase separation to proceed without interruption while maintaining extraction efficiency.
Solution Approach 2:
The patent changes operational parameters such as solvent composition, flow rates, or temperature to prevent rag layer formation or to facilitate its removal. By adjusting these parameters, the system maintains reliable phase separation while continuing to achieve high extraction efficiency.
2Productivity
If continuous extraction is performed to maintain productivity, then the process operates without interruption, but the rag layer accumulates and must be continuously removed to avoid shutdown
Solution Approach 1:
The patent designs the extraction system to continuously remove or neutralize the rag layer through the intermediary substance, ensuring that phase separation continues uninterrupted. This maintains continuous operation without requiring periodic shutdowns for manual cleaning.
Solution Approach 2:
The system uses a portion of its own output (rafficinate or recycled solvent) as the intermediary substance to automatically clean the interface. This self-service mechanism eliminates the need for external intervention or complex additional equipment to remove the rag layer.
3Quantity of substance
If extraction solvent is used to recover diphosphite-containing compounds, then catalyst recovery is achieved, but emulsion phase forms that reduces settling rate and increases separation time
Solution Approach 1:
The intermediary substance acts as a breaking agent for the emulsion phase, facilitating faster separation of the extracted compounds from the solvent. This reduces the settling time while maintaining complete recovery of the diphosphite-containing compounds.
Solution Approach 2:
The patent adjusts extraction parameters such as solvent-to-feed ratio, mixing intensity, or temperature to optimize the balance between extraction efficiency and settling rate. By controlling these parameters, the system achieves rapid phase separation without compromising compound recovery.
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 reduces the size and formation rate of the emulsion phase, increases the rate of settling, and enhances the recovery of diphosphite-containing compounds, thereby improving the extraction efficiency and preventing process shutdowns due to rag layer buildup.
Implementation Method 1
recovery of diphosphite-containing compounds from a mixture comprising diphosphite-containing compounds and organic dinitriles using liquid-liquid extraction
Implementation Method 2
a light phase separates from a heavy phase in the settling section, wherein the light phase comprises extraction solvent and extracted diphosphite-containing compounds, wherein the heavy phase comprises organic mononitriles and organic dinitriles
Data Source
AI summary
Disclosed herein are methods for recovering diphosphite-containing compounds from mixtures comprising organic mononitriles and organic dinitriles, using liquid-liquid extraction. Also disclosed are treatments to enhance extractability of the diphosphite-containing compounds.