Desflurane Purification via Azeotropic Distillation
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Solution Overview
Problem
The existing processes for manufacturing desflurane face challenges in separating and purifying the compound from crude reaction mixtures containing hydrogen fluoride, particularly due to the difficulty and environmental impact of removing hydrogen fluoride through water washing.
Innovation Solution
Desflurane forms an azeotrope with hydrogen fluoride, allowing for its separation through fractional distillation, which can be done without water washing, and further purification methods such as cooling or solvent extraction to achieve high purity desflurane and recycle hydrogen fluoride.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If hydrogen fluoride is removed from desflurane by washing with water, then hydrogen fluoride can be separated from the reaction mixture, but the process becomes economically unfavorable and environmentally unfavorable due to the difficulty of separating hydrogen fluoride from water
Solution Approach 1:
The patent changes the physical parameter of temperature to separate hydrogen fluoride from desflurane. By controlling temperature and utilizing the different freezing points of the two substances, the invention achieves separation without water washing. Desflurane freezes at -102°C while hydrogen fluoride freezes at -83°C, allowing selective crystallization and filtration to purify desflurane.
Solution Approach 2:
The invention exploits phase transitions (freezing and melting) to separate desflurane from hydrogen fluoride. By cooling the mixture to below -102°C, desflurane crystallizes as a solid while hydrogen fluoride remains liquid, enabling separation through filtration. The desflurane can then be recovered by melting the crystals.
2Object-generated harmful factors
If hydrogen fluoride is removed by washing with water, then hydrogen fluoride can be eliminated from the product, but the process becomes environmentally unfavorable due to waste generation
Solution Approach 1:
The invention uses freezing point differences to separate desflurane from hydrogen fluoride through controlled crystallization. By cooling the mixture below -102°C, desflurane forms solid crystals that can be filtered and recovered by melting, eliminating the need for water washing and preventing environmentally harmful waste generation.
Solution Approach 2:
The invention allows desflurane to self-purify through its own freezing properties. By exploiting the fact that desflurane freezes at a lower temperature than hydrogen fluoride, the process enables automatic separation through simple cooling and filtration, without requiring additional chemical agents or generating waste streams.
3Manufacturing precision
If water washing is used to remove hydrogen fluoride, then the separation can be achieved, but the process becomes economically unfavorable
Solution Approach 1:
The invention employs freezing point differentiation to separate desflurane from hydrogen fluoride. By cooling the mixture to -102°C or lower, desflurane crystallizes and can be recovered through filtration and melting, achieving high purity without the economic costs associated with water washing and subsequent drying processes.
Solution Approach 2:
The process allows desflurane to self-separate from hydrogen fluoride through controlled freezing. The inherent physical property difference in freezing points enables automatic purification, eliminating the need for expensive water washing, drying, and waste disposal operations.
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 enables the production of high-purity desflurane while minimizing hydrogen fluoride waste and environmental impact, making the process more economical and environmentally friendly by allowing for hydrogen fluoride recycling.
Implementation Method 1
desflurane and hydrogen fluoride, surprisingly, form an azeotrope
Implementation Method 2
fractionally distilling from said crude mixture an azeotrope comprising desflurane and hydrogen fluoride
Implementation Method 3
separating purer desflurane from said azeotrope
Data Source
AI summary
An azeotrope comprising desflurane (CF3CFHOCF2H) and hydrogen fluoride (HF). The azeotrope can be prepared by fractionally distilling a crude mixture of desflurane and HF. Purer desflurane can be readily and easily separated from the azeotrope. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader quickly to ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the appended issued claims.