Esterification Recirculation Loop for Alkyl Acrylate Purity
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Solution Overview
Problem
The complexity of purification steps in the manufacture of C 4 -C 10 alkyl (meth)acrylates by direct esterification with a cationic resin catalyst leads to low productivity and high impurity levels, making it difficult to achieve high purity products.
Innovation Solution
A process involving direct esterification of (meth)acrylic acid with alcohol using a cationic resin catalyst, where the alcohol/acid molar ratio is between 1.4 and 3, and the reaction water is eliminated as an azeotrope with the esterifying alcohol, utilizing a recirculation loop including a distillation column to simplify purification and minimize secondary reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex purification steps are used to obtain high purity product, then product purity is improved, but productivity deteriorates
Solution Approach 1:
The invention changes the reaction parameters by using an excess of alcohol (molar ratio alcohol/acid between 1.4 and 3) and implementing a specific recirculation rate (mass ratio between 6 and 25). These parameter changes shift the reaction equilibrium and minimize secondary reactions, resulting in high purity products while maintaining high productivity through simplified purification steps.
Solution Approach 2:
The invention implements a continuous recirculation loop where the reaction mixture is continuously circulated between the esterification reactor and the distillation column. This continuous action ensures complete elimination of water as an azeotrope with the esterifying alcohol, driving the reaction to completion and producing high purity ester with minimal impurities, thereby simplifying downstream purification while maintaining high productivity.
2Productivity
If excess alcohol is used to simplify purification, then productivity is improved, but separation complexity increases
Solution Approach 1:
The invention extracts water from the reaction mixture by forming and eliminating an azeotrope with the excess alcohol in a distillation column. This selective removal of water simplifies the separation process because the excess alcohol and ester have similar boiling points and are difficult to separate, but water forms a distinct azeotrope that can be easily removed, thereby simplifying the overall separation complexity while maintaining high productivity.
3Quantity of substance
If recirculation loop is implemented to eliminate water, then yield is optimized, but process complexity increases
Solution Approach 1:
The invention merges the esterification reactor and the distillation column into a single integrated recirculation loop system. The reaction mixture flows continuously from the reactor to the distillation column and back to the reactor, combining the reaction and water removal functions in one system. This integration optimizes yield by continuously driving the equilibrium toward product formation while the added complexity is manageable due to the straightforward recirculation configuration.
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 simplifies downstream purification, reduces heavy by-product formation, and achieves high-purity alkyl (meth)acrylates with improved yield and reduced impurities, facilitating easier separation and treatment.
Implementation Method 1
direct esterification of (meth)acrylic acid with the corresponding alcohol, this reaction being catalyzed by a cationic resin
Implementation Method 2
the reaction water being eliminated in the form of an azeotrope with the esterifying alcohol from a distillation column
Implementation Method 3
reaction water being eliminated in the form of an azeotrope with the esterifying alcohol from a distillation column
Data Source
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AI summary
The present invention relates to a method for producing a C4-C10 alkyl (meth)acrylate, by direct esterification of (meth)acrylic acid by the corresponding alcohol, the reaction water being removed in the form of an azeotrope with the esterification alcohol from a distillation column mounted over the esterification reactor comprising a cationic resin as a catalyst. Said method is characterized in that the molar ratio of alcohol to acid at the inlet of the reactor is between 1.4 and 3, and in that the crude reaction mixture circulates in a recirculation loop joining the reactor and the water removal column, at a recirculation rate of between 6 and 25, expressed by the mass ratio between the flow fed into the loop and the flow sent to a purification treatment.