Continuous n-Butyl (Meth)acrylate Production With Catalyst Recirculation
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Solution Overview
Problem
Existing methods for producing n-butyl (meth)acrylate face challenges in catalyst recovery, water discharge, and energy efficiency, leading to unwanted emissions and secondary component formation, with limited applicability to n-butyl acrylate production.
Innovation Solution
A continuous process involving esterification with catalyst recycling, phase separation, and controlled azeotropic distillation, utilizing a rectification column and phase separators to minimize water content and optimize catalyst recovery, achieving greater conversion and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If water of esterification is removed by distillation to shift equilibrium, then conversion rate increases, but energy consumption increases and secondary components form
Solution Approach 1:
The patent utilizes azeotropic distillation where water forms a heterogeneous azeotrope with n-butyl (meth)acrylate and n-butanol. By controlling the phase transition and separation of this azeotrope, water is efficiently removed from the reaction mixture, shifting the esterification equilibrium forward to improve conversion rate while managing energy consumption through optimized distillation conditions.
Solution Approach 2:
The patent optimizes distillation parameters including temperature, pressure, and reflux ratio to efficiently remove water through azeotropic distillation. By carefully controlling these parameters, the process achieves high conversion rates while minimizing energy consumption and preventing excessive formation of secondary components from prolonged high-temperature exposure.
2Device complexity
If catalyst is discharged with water to simplify separation, then process complexity reduces, but catalyst recovery rate decreases and emissions increase
Solution Approach 1:
The patent implements a catalyst recovery system where the acidic catalyst is separated from the aqueous phase and recycled back to the esterification reactor. Instead of discharging the catalyst with water, the process captures and recovers the catalyst, maintaining high recovery rates while reducing SOx emissions from incineration and minimizing catalyst loss.
Solution Approach 2:
The patent establishes a feedback loop where catalyst activity is monitored and the recovered catalyst is returned to the reaction system. This closed-loop approach maintains catalyst concentration and activity, ensuring continuous efficient operation while reducing the need for fresh catalyst addition and minimizing environmental emissions.
3Productivity
If high temperature distillation is used to remove water quickly, then separation efficiency increases, but secondary components increase and energy consumption increases
Solution Approach 1:
The patent exploits the phase transition behavior of the heterogeneous azeotrope formed during distillation. By controlling the condensation and phase separation of the azeotrope, water is efficiently removed through phase change rather than requiring excessive high-temperature distillation, thereby reducing secondary component formation while maintaining separation efficiency.
4Productivity
If sulfuric or sulfonic acids are used as catalysts for esterification, then reaction rate increases, but SOx emissions increase when catalyst is incinerated
Solution Approach 1:
The patent recovers the acidic catalyst from the reaction mixture and prevents its incineration. By implementing catalyst recycling, the process eliminates the need to burn off sulfur-containing catalysts, thereby preventing SOx emissions while maintaining the high reaction rates provided by sulfuric or sulfonic acid catalysts.
Solution Approach 2:
The patent converts the potential harm of using sulfur-containing catalysts (which would generate SOx emissions upon incineration) into a benefit by implementing a recovery and recycling system. The catalyst that would otherwise be a source of pollution is instead recovered and reused, transforming an environmental liability into a sustainable process asset.
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 enhances catalyst recovery, reduces energy consumption, minimizes secondary components, and improves the yield of n-butyl (meth)acrylate by maintaining low water content and efficient phase separation.
Implementation Method 1
removing the azeotropes water/n-butyl (meth)acrylate, n-butanol/n-butyl (meth)acrylate, n-butanol/water, and n-butanol/n-butyl (meth)acrylate/water by distillation in a rectification column
Implementation Method 2
separates water, n-butanol and n-butyl (meth)acrylate from each other by distillation
Implementation Method 3
condensing the vapor stream to form an organic phase and an aqueous phase, and continuously separating the organic phase from the aqueous phase
Implementation Method 4
condensing the vapor stream to form an organic phase and an aqueous phase
Implementation Method 5
performing an esterification with (meth)acrylic acid and n-butanol to obtain water and n-butyl (meth)acrylate
Data Source
AI summary
The invention relates to a method for continuously producing n-butyl(meth)acrylate by reacting (meth)acrylic acid with n-butanol in the presence of an acid catalyst and a polymerization inhibitor. In a first embodiment, the method has the steps of: *carrying out an esterification within a reactor (A) comprising a column (B) installed thereon, wherein the components (meth)acrylic acid and n-butanol are used in a molar ratio ranging from 1.0:1.0 to 10:2.0, preferably 1.0:1.1 to 1.0:1.5, and the esterification is carried out at a temperature ranging from 80 to 150° C., preferably 100 to 130° C., and an absolute pressure ranging from 0.2 to 5.0 bar, preferably 0.4 to 1.5 bar, whereby a resulting reaction product (6) and a vapor flow are obtained at the head of the column (B), *discharging the vapor flow at the head of the column (B), *condensing the vapor flow in a condenser (C), thereby forming an organic phase, which is enriched with n-butyl(meth)acrylate, and an aqueous phase, *continuously separating the organic phase from the aqueous phase by means of a phase separator (D), *supplying the resulting reaction product (6) to a rectification column (E), *separating the azeotrope within the rectification column (E) consisting of: a) water and n-butyl(meth)acrylate, b) n-butanol and n-butyl(meth)acrylate, c) n-butanol and water, and d) n-butanol, n-butyl(meth)acrylate, and water, wherein the rectification column (E) is operated at a sump temperature ranging from 80 to 150° C. and at a temperature at the head ranging from 70 to 130° C. and an absolute pressure ranging from 0.2 to 5 bar, preferably 0.4 to 1.5 bar, *discharging a gas flow enriched with the azeotrope at the head of the rectification column (E), *condensing the gas flow in a condenser (F), thereby forming an organic phase, which is enriched with n-butyl(meth)acrylate, and an aqueous phase, *continuously separating the organic phase from the aqueous phase by means of a phase separator (G), *continuously discharging at least one part of the organic phase out of the phase separator (G), said discharged part of the n-butyl(meth)acrylate-enriched organic phase constituting the raw product flow (15), *discharging a high-boiling sump discharge (23) out of the sump of the rectification column (E), the mass flow ratio of the high-boiling sump discharge (23) to the (meth)acrylic acid supplied to the reactor (A) as a reactant ranging from 0.5 to 5, *supplying a high-boiling sub-flow (7) of the discharged high-boiling sump discharge (23) to a mixer (H), the mass flow ratio of the high-boiling sub-flow (7) to the high-boiling sump discharge (23) ranging from 0.01 to 0.5, preferably 0.05 to 0.08, *supplying a mixture (10) resulting from the mixer (H) to an extraction phase separator (I) arranged downstream thereof, and *continuously separating the mixture in the extraction phase separator (I), thereby obtaining an organic raffinate (11) and an aqueous catalyst-containing extract (12), said aqueous extract (12) being at least partly recirculated to the reactor (A) and/or the rectification column (E), wherein—a sub-flow of the aqueous phase (18) from the phase separator (G), —a sub-flow of the aqueous phase (26) from the phase separator (D) and/or —a sub-flow of the aqueous phase (5) from the phase separator (D) is supplied to the phase separator (G), and subsequently a sub-flow of the aqueous phase (18) from the phase separator (G) is supplied to the mixer (H). The mass flow ratio of the sub-flow of the aqueous phase (18) to the high-boiling sub-flow (7) of the discharged high-boiling sump discharge (23) ranges from 0.08 to 0.50, and the mass flow ratio of the sub-flow of the aqueous phase (5) to the high-boiling sub-flow (7) of the discharged high-boiling sump discharge (23) ranges from 0.08 to 0.50.