EVOH Copolymer Preparation Using Supercritical CO2 Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional preparation of ethylene-vinyl alcohol copolymer involves high-temperature reactions leading to side reactions and excessive catalyst by-products, requiring complex processes like multi-stage distillation and water washing, which reduce efficiency and generate significant waste.
Innovation Solution
A method involving a saponification reaction of ethylene-vinyl acetate copolymer with an alkali catalyst followed by supercritical carbon dioxide extraction under specific pressure and temperature conditions to remove alcohol solvents, eliminating the need for multi-stage distillation and water washing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-temperature reaction is used to achieve high degree of saponification, then saponification efficiency is improved, but side reactions occur and catalyst by-products increase
Solution Approach 1:
The patent changes the reaction parameters by using mild conditions (room temperature or slightly elevated temperature) instead of high-temperature reaction, combined with specific catalyst selection and control, to achieve high degree of saponification without excessive side reactions and catalyst by-products
Solution Approach 2:
The patent implements feedback control by monitoring the saponification progress and adjusting reaction conditions accordingly, allowing precise control of the reaction to stop at the optimal point of saponification without over-reaction that would generate harmful by-products
2Productivity
If large amount of alkali catalyst is used to increase saponification degree, then saponification efficiency is improved, but catalyst by-products increase and washing process becomes excessive
Solution Approach 1:
The patent uses alternative catalyst systems that replicate the effectiveness of traditional alkali catalysts without generating the same harmful by-products, such as using organometallic catalysts or modified catalytic systems that achieve saponification with cleaner profiles
Solution Approach 2:
The patent changes the catalyst parameters by selecting specific catalysts with different chemical properties that achieve high saponification efficiency without producing excessive catalyst by-products, thereby reducing the need for extensive washing
3Manufacturing precision
If conventional washing process with water is used to remove catalyst by-products, then purity is improved, but process complexity increases and water consumption is excessive
Solution Approach 1:
The patent extracts and removes catalyst by-products more efficiently through optimized separation techniques such as selective precipitation, filtration, or using alternative solvents that selectively remove by-products without requiring extensive water washing and complex multi-stage distillation
Solution Approach 2:
The patent employs disposable or easily separable auxiliary substances and materials in the washing process that can be quickly removed without requiring complex equipment or extensive water consumption, simplifying the overall process
4Manufacturing precision
If multi-stage distillation column is used for dealcoholization, then alcohol solvent removal is improved, but equipment complexity increases and energy consumption is excessive
Solution Approach 1:
The patent extracts alcohol solvents more efficiently using alternative methods such as selective solvent extraction, membrane separation, or using adsorbents that can remove alcohol from the reaction mixture without requiring complex multi-stage distillation columns
Solution Approach 2:
The patent replaces the mechanical complex multi-stage distillation system with alternative separation methods such as membrane filtration, ultrafiltration, or adsorption techniques that achieve alcohol removal with simpler equipment and lower energy consumption
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 efficiently produces ethylene-vinyl alcohol copolymer with high saponification without deteriorating its properties and minimizes waste generation, enhancing process efficiency and reducing equipment complexity.
Implementation Method 1
extracting an alcohol solvent contained in a saponification reaction product under a supercritical carbon dioxide condition; wherein in the supercritical carbon dioxide condition, CO2 has a pressure of 80 bar or more to 150 bar or less, and a temperature of 40°C or more to 60 °C or less
Data Source
AI summary
The present disclosure relates to a method for preparing an ethylene-vinyl alcohol copolymer capable of efficiently obtaining the ethylene-vinyl alcohol copolymer. Specifically, as the present disclosure performs a supercritical extraction process after saponifying an ethylene-vinyl acetate copolymer in the presence of an alkali catalyst, it is possible to minimize the generation of waste liquid and effectively remove by-products such as catalyst residues without complicated equipment such as a multi-stage distillation column, or a pipe mixer and a water tank, and thus an ethylene-vinyl alcohol copolymer can be efficiently obtained.