Dialkyl Ester Preparation via Countercurrent Vapor-Liquid Contact
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Solution Overview
Problem
Current methods for preparing dialkyl esters of 2,5-furandicarboxylic acid face challenges such as incomplete purification, sub-optimal yield, and high energy consumption due to the removal of water and alcohol vapor streams, which complicates separation and reduces the efficiency of the esterification reaction.
Innovation Solution
A countercurrent contact process between a vaporous alkanol and 2,5-furandicarboxylic acid in a liquid phase is employed, where the alkanol vapor entrains water, shifting the esterification equilibrium and allowing for efficient separation of dialkyl esters, with methanol being preferred for its low boiling point and ease of separation, and using a reactive stripping column with inert or catalytically active packing to enhance contact and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If water and alcohol are removed from the reaction mixture by vaporization, then the esterification equilibrium is shifted towards product formation, but the vapor stream becomes large requiring high energy consumption and complicating rectification
Solution Approach 1:
The patent extracts only water from the reaction mixture using a drying agent, leaving alcohol in the reaction system. This selective removal shifts the esterification equilibrium toward product formation without requiring vaporization and rectification of large vapor streams containing both alcohol and water, thereby reducing energy consumption while maintaining high esterification yield
Solution Approach 2:
The patent changes the physical state parameter of water by using a drying agent to absorb water from the liquid reaction mixture. This approach transforms the water removal process from vaporization (high energy) to absorption (low energy), maintaining equilibrium shift while dramatically reducing energy requirements
2Productivity
If water and alcohol are removed by vaporization, then the reaction equilibrium shifts, but the separation becomes complicated due to the range of boiling points of components
Solution Approach 1:
The patent uses a drying agent to selectively extract water from the reaction mixture, avoiding the need for vaporization and rectification. This eliminates the complexity associated with separating components having different boiling points (water, alcohol, monoester, diester) while still achieving equilibrium shift through water removal
Solution Approach 2:
The patent introduces a drying agent as an intermediary substance that facilitates water removal without requiring thermal energy input or complex separation equipment. The drying agent acts as a mediator between the reaction mixture and water removal, simplifying the overall process while maintaining high productivity
3Ease of operation
If monoester is removed together with alcohol and water, then the vapor stream is easier to handle, but the production of desired diester becomes sub-optimal
Solution Approach 1:
The patent extracts only water from the reaction mixture using a drying agent, leaving both alcohol and monoester in the liquid phase. This selective extraction maintains optimal conditions for diester formation by keeping all reactants and intermediates in the reaction system, while still achieving water removal to shift equilibrium
Solution Approach 2:
The patent maintains homogeneity in the liquid reaction phase by keeping alcohol, monoester, and diester together in the same phase. This avoids the separation of monoester into the vapor phase, ensuring it remains available for further esterification to diester, thereby optimizing diester production
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 process improves the yield of dialkyl esters by effectively removing water vapor, reducing energy consumption, and simplifying separation, resulting in a more efficient and purified product compared to existing methods.
Implementation Method 1
contacting a vaporous stream of an alkanol countercurrently with the at least partially liquid starting material comprising the 2,5-furandicarboxylic acid in a reaction zone to conduct an esterification reaction to the dialkyl ester of 2,5-furandicarboxylic acid and water
Implementation Method 2
the alkanol vapor entrains water, shifting the esterification equilibrium and allowing for efficient separation of dialkyl esters
Implementation Method 3
withdrawing a reaction vapor comprising the alkanol and water from the reaction zone
Implementation Method 4
A countercurrent contact process between a vaporous alkanol and 2,5-furandicarboxylic acid in a liquid phase is employed
Implementation Method 5
using a reactive stripping column with inert or catalytically active packing to enhance contact and separation
Data Source
Figure 1~2
AI summary
Dialkyl esters of 2,5-furandicarboxylic acid are prepared from a 2,5-furandicarboxylic acid-containing starting materialin a process, which comprises: -contacting a vaporous stream of an alkanol countercurrently with the at least partially liquid starting material comprising the 2,5-furandicarboxylic acid, in a reaction zone to conduct an esterification reaction to yield the dialkyl ester of 2,5-furandicarboxylic acid and water; - withdrawing a reaction vapor comprising the alkanol and water from the reaction zone; - discharging a liquid phase comprising at least the dialkyl ester of 2,5-furandicarboxylic acid, from the bottom part of the reaction zone, to obtain the dialkyl ester of 2,5-furandicarboxylic acid.