1,4-Butanediol Purification via Ion Exchange Resins
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Solution Overview
Problem
Current processes for producing 1,4-butanediol from renewable sources result in impurities that reduce the purity and stability of the final product, affecting the quality of biodegradable polyesters, particularly due to high contents of 2-pyrrolidone and 2-(4′-hydroxybutoxy)-tetrahydrofuran, which impact hydrolysis resistance and productivity.
Innovation Solution
A process involving the use of cationic and anionic exchange resins at specific pH ranges followed by distillation to purify 1,4-butanediol, reducing 2-pyrrolidone content to less than 6 ppm and 2-(4′-hydroxybutoxy)-tetrahydrofuran to less than 800 ppm, enhancing the purity and stability of the diol for polyester synthesis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If 1,4-butanediol is produced from renewable sources via fermentation, then the use of non-renewable resources decreases and CO2 emissions decrease, but the product contains high levels of impurities that reduce polyester quality
Solution Approach 1:
The purification process is divided into multiple sequential stages: first distillation to remove volatile impurities, followed by ion exchange to remove nitrogen-containing compounds, then a second distillation to remove 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran. This segmented approach achieves high purity while maintaining renewable source production
Solution Approach 2:
The process controls and adjusts various parameters including distillation temperatures, ion exchange resin types and quantities, pH levels during ion exchange, and residence times to optimize the removal of specific impurities while preserving the 1,4-butanediol product
2Ease of manufacture
If high contents of impurities such as 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran are present in 1,4-butanediol, then the fermentation process is simpler, but the resulting polyesters have reduced hydrolysis resistance and productivity
Solution Approach 1:
The process specifically extracts and removes harmful impurities: 2-pyrrolidone is removed through controlled distillation at specific temperature ranges, while 2-(4'-hydroxybutoxy)-tetrahydrofuran is removed through ion exchange resins and subsequent distillation, thereby improving polyester hydrolysis resistance without complicating the fermentation process
Solution Approach 2:
Ion exchange resins are introduced as intermediary materials to selectively bind and remove nitrogen-containing impurities and cyclic by-products from the 1,4-butanediol stream, protecting the final polyester product from hydrolysis degradation
3Device complexity
If conventional distillation is used to purify 1,4-butanediol, then the purification process is simpler, but it cannot effectively remove 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran impurities
Solution Approach 1:
The process merges multiple purification techniques: conventional distillation is combined with ion exchange treatment, followed by additional distillation steps. This combination achieves effective removal of 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran while maintaining overall process manageability
4Quantity of substance
If impurities are present in 1,4-butanediol from renewable sources, then the production cost is lower, but the polyester synthesis requires substantial changes in process conditions to adjust final viscosity
Solution Approach 1:
The purification process is performed preliminarily before polyester synthesis to remove impurities that would otherwise require adjustments in polymerization conditions. By pre-removing 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran, the polyester synthesis can proceed under standard conditions without requiring substantial changes to achieve desired viscosity
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 achieves a 1,4-butanediol composition with a concentration of 99.0% by weight and low impurity levels, maintaining stable APHA color values over time, eliminating the need for post-treatment purification and enabling the production of biodegradable polyesters with improved mechanical properties.
Implementation Method 1
A process involving the use of cationic and anionic exchange resins at specific pH ranges followed by distillation to purify 1,4-butanediol
Implementation Method 2
followed by distillation to purify 1,4-butanediol, reducing 2-pyrrolidone content to less than 6 ppm and 2-(4'-hydroxybutoxy)-tetrahydrofuran to less than 800 ppm
Implementation Method 3
1,4-butanediol may be obtained from renewable sources by means of fermentation processes starting from carbohydrates such as sugars and lignocellulose biomass
Data Source
AI summary
The invention relates to a process for the production of 1,4-butanediol comprising the preparation of a fermentation broth comprising 1,4-butanediol from renewable sources and water, separation of a liquid fraction comprising said 1,4-butanediol and water from one or more solid fractions, said liquid fraction comprising 2-pyrrolidone in an amount higher than 80 ppm, one or more passages of the resulting liquid fraction through a bed comprising one or more cation-exchange resins thereby providing an output pH of said liquid fraction from 4 to 2, one or more passages of the resulting liquid fraction through a bed comprising one or more anion-exchange resins thereby providing an output pH of said liquid fraction from 8 to 11, and the distillation of the liquid fraction thereby provided so as to obtain a composition having a concentration of said 1,4-butanediol higher than 99.0% by weight and comprising 2-pyrrolidone in an amount lower than 6 ppm. The resulting composition should exhibit an APHA color value after ageing of less than 30.