Brønsted Acid Ionic Liquid Catalyst for Bio-Polyol Synthesis
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Solution Overview
Problem
Current methods for producing bio-polyols from epoxidized fatty acid esters involve the use of strong acids and alkalis, leading to environmental issues such as carbonization, waste production, and high costs, as well as the non-recyclability of catalysts, which pose challenges in green manufacturing processes.
Innovation Solution
A method utilizing Brønsted acid ionic liquids synthesized with alkyl sulfonic acid, where the molar ratio of alkyl sulfonic acid and Brønsted strong acid is within 1.0 to 1.5, is used to catalyze the ring-opening hydroxylation of epoxidized fatty acid esters with alcohols, allowing for the recycling of ionic liquids and reducing environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If strong acids (sulfuric acid, boron trifluoride, tetrafluoroboric acid, phosphate) are used for ring-opening hydroxylation of epoxidized fatty acid esters, then the hydroxylation reaction can be carried out, but the process causes carbonization of raw materials or products, produces waste water, and the acids are non-recyclable and highly caustic
Solution Approach 1:
The patent changes the chemical state and properties of the catalyst from traditional strong acids to ionic liquids with adjustable acidity. By modifying the ionic liquid structure (changing cations and anions) and reaction parameters (temperature, time, catalyst loading), the process achieves effective hydroxylation while eliminating carbonization and enabling catalyst recycling, thus resolving the contradiction between reaction capability and harmful effects
Solution Approach 2:
The patent uses composite ionic liquid systems combining different cations (e.g., imidazolium, pyridinium) and anions (e.g., BF4-, PF6-, OTf-) to create catalysts with optimized properties. These composite ionic liquids provide both the necessary catalytic activity for hydroxylation and the stability/recyclability needed to eliminate waste and harmful effects, resolving the technical contradiction
2Reliability
If strong alkali solution is used after ring-opening hydroxylation to neutralize acids, then the pH can be adjusted, but the manufacture cost increases and waste water is produced
Solution Approach 1:
The ionic liquid catalyst system is designed to be inherently stable and non-corrosive, eliminating the need for post-reaction neutralization with strong alkalis. The catalyst maintains stable pH characteristics throughout the reaction and can be directly recycled without additional neutralization steps, thus achieving reliable pH control without the associated costs and waste water production
Solution Approach 2:
The patent enables direct recovery and recycling of the ionic liquid catalyst through simple separation and distillation processes, eliminating the need for neutralization and waste water treatment steps. The catalyst is recovered in high purity and reused in subsequent reactions, eliminating both the cost and environmental burden of alkali neutralization
3Ease of manufacture
If boron trifluoride is used as catalyst, then ring-opening hydroxylation can be achieved, but the catalyst makes smokes in humid air and is toxic
Solution Approach 1:
The patent replaces volatile, toxic gaseous catalysts like boron trifluoride with stable, non-volatile ionic liquid catalysts that do not produce smoke or toxic emissions. The ionic liquids can be handled safely without special precautions against vapor inhalation, eliminating the harmful effects while maintaining catalytic activity for hydroxylation
Solution Approach 2:
The ionic liquid acts as an intermediary catalyst that provides the necessary acid catalysis for ring-opening hydroxylation without the harmful volatility and toxicity of traditional gaseous acid catalysts. The ionic liquid structure allows tunable acidity while maintaining physical stability and safety, resolving the contradiction between reaction capability and harmful effects
4Object-affected harmful factors
If organic alkali is used to avoid corrosion to reaction tank or pipes, then corrosion is reduced, but the organic alkali must be neutralized by acidic substances and absorbed by adsorbent, thus increasing cost
Solution Approach 1:
The ionic liquid catalyst system is inherently stable and non-corrosive to reaction equipment, eliminating the need for protective measures or post-reaction neutralization with adsorbents. The catalyst can be directly separated and recycled without additional cost-incurring steps, achieving both corrosion resistance and cost efficiency
Solution Approach 2:
The patent enables direct recovery of the ionic liquid catalyst through simple separation and distillation without requiring neutralization by acidic substances or absorption by adsorbents. This eliminates the additional cost steps while maintaining corrosion resistance, as the ionic liquid itself is the non-corrosive element
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 enables the production of bio-polyols with high yields and reduced pollution, as the ionic liquids are recyclable, and the process minimizes corrosion and waste, achieving a more sustainable green manufacturing process for bio-polyols.
Implementation Method 1
Brønsted acid ionic liquids synthesized with alkyl sulfonic acid, where the molar ratio of alkyl sulfonic acid and Brønsted strong acid is within 1.0 to 1.5, is used to catalyze the ring-opening hydroxylation of epoxidized fatty acid esters with alcohols
Implementation Method 2
the reaction solution is heated within a temperature of 30° C. to 100° C. for 1 to 24 hours to cause ring-opening hydroxylation
Implementation Method 3
extracting and layering the reaction solution by using deionized water to acquire upper-layer solution and lower-layer solution
Data Source
AI summary
A method of preparing bio-polyols from epoxidized fatty acid esters, wherein the bio-polyols are synthesized via hydroxylation with epoxidized fatty acid esters and ring-opening reagent, using the acidic ionic liquids as catalysts. The bio-polyols are used to synthesize bio-polyurethane and bio-polyurethane foams. The acidic ionic liquids in this process is used in esterification, epoxidation, and ring-opening reaction to synthesize bio-polyols. The ionic liquids catalysts have several advantages such as easy to separate, reusable, and may reduce pollution.