Organophosphite Purification via Weakly Basic Adsorbent
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Solution Overview
Problem
Existing processes for producing organophosphites struggle with maintaining stability due to acidic impurities, leading to hydrolytic degradation, and there is a need for a simple method to reduce phosphorous acid content for long-term storage stability and reprocessing partially degraded phosphites.
Innovation Solution
A process involving recrystallization or trituration of solid organophosphite compounds, followed by dissolution in an organic solvent and treatment with a weakly basic adsorbent to reduce acid content to 30 ppm or less, using a weakly basic ion exchange resin or metal oxide, and subsequent filtration and concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If water or water/amine extraction is used to remove acidic impurities during organophosphite production, then some acid removal is achieved, but significant amounts of residual phosphorous acid remain in the final product
Solution Approach 1:
The patent employs a two-stage extraction process: first using water to remove water-soluble acidic impurities, then using an organic base (such as triethylamine or pyridine) in an organic solvent to extract and remove phosphorous acid that remains after the water extraction step. This sequential extraction approach ensures that residual acid content is reduced to extremely low levels, thereby improving long-term storage stability.
Solution Approach 2:
The patent introduces an organic base (mediator substance) such as triethylamine or pyridine that acts as an intermediary between the phosphorous acid and the final product. The organic base forms a complex with phosphorous acid, enabling its removal from the organophosphite solution. This mediator approach allows for more effective acid removal compared to direct neutralization, achieving the required low acid content for stable storage.
2Reliability
If extreme measures are taken to reduce phosphorous acid content to ensure storage stability, then storage stability improves, but process complexity increases
Solution Approach 1:
The patent performs preliminary removal of water-soluble acidic impurities through water extraction before the main organophosphite production step is completed. By removing these impurities early in the process, the subsequent steps are simplified, and the final acid removal using organic base becomes more efficient. This preliminary action prevents the need for more complex post-processing steps.
Solution Approach 2:
The patent changes the chemical environment parameters by transitioning from aqueous extraction to organic solvent-based extraction with organic bases. This parameter change (from water to organic solvent system) enables more effective removal of phosphorous acid while maintaining a relatively simple process flow. The specific choice of organic base and solvent ratios are optimized to achieve maximum acid removal with minimum process complexity.
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 effectively reduces phosphorous acid content to extremely low levels, ensuring long-term storage stability and allowing for the reprocessing of degraded phosphites, resulting in a stable organophosphite product suitable for hydroformylation processes.
Implementation Method 1
treating the solution with a weakly basic adsorbent
Implementation Method 2
the use of sodium methoxide as an additive in a washing step during the purification phase of the ligand manufacturing process to address the issue of acidic impurities
Data Source
AI summary
The present invention relates to processes for producing organophosporous compositions having low acid content as well as processes for reprocessing partially degraded organophosporous compositions that contain high levels of phosphorous acid. In one embodiment, a process comprises: (a) receiving a solid organophosphite compound that has been recrystallized or triturated, wherein the solid organophosphite compound comprises phosphorous acid; (b) dissolving the solid organophosphite compound in an organic solvent; (c) treating the solution with a weakly basic adsorbent; and (d) collecting the treated organophosphite solution, wherein the acid content of the organophosphite following step (d) is 30 ppm or less.