(Meth)acrylic Acid Purification via Eutectic Crystallization
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Solution Overview
Problem
Current methods for purifying (meth)acrylic acid, such as crystallization followed by washing, face challenges with high hydraulic pressure and energy consumption, especially in large-scale industrial use, and often require multiple steps to achieve high purity, which can be costly and inefficient.
Innovation Solution
A process involving crystallization of (meth)acrylic acid and water at temperatures around the eutectic point to form crystals, which are then separated and partially melted for washing, reducing the need for additional purification steps and energy consumption, while maintaining high purity through a simple and cost-effective method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If (meth)acrylic acid crystals are crystallized from an aqueous melt and washed with crystal melt, then purification effectiveness is improved, but hydraulic pressure becomes too high for large-scale industrial use
Solution Approach 1:
The patent changes the temperature parameter during crystallization to operate near the eutectic point, which modifies the physical properties of the crystal bed and reduces hydraulic pressure while maintaining purification effectiveness
Solution Approach 2:
The patent introduces an intermediary washing step using a small amount of crystal melt to wash the crystals after separation, which effectively removes impurities without requiring high hydraulic pressure for continuous washing
2Manufacturing precision
If (meth)acrylic acid crystals are melted and washed in prior art processes, then purification is achieved, but energy consumption becomes too high
Solution Approach 1:
The patent applies partial melting rather than complete melting of the crystal bed, and uses a small amount of crystal melt for washing instead of large volumes, thereby achieving sufficient purification with reduced energy input
Solution Approach 2:
The patent operates at temperatures near the eutectic point and controls the melting temperature range to minimize energy consumption while still achieving effective crystal washing and purification
3Manufacturing precision
If multiple crystallization and washing steps are performed, then high purity is achieved, but process complexity and cost increase
Solution Approach 1:
The patent combines crystallization, separation, and washing steps into an integrated process that operates near the eutectic point, achieving high purity in a single unified operation rather than through multiple separate steps
Solution Approach 2:
The process uses the crystals themselves to generate the washing melt, eliminating the need for external washing agents or additional complex purification equipment
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 effectively purifies (meth)acrylic acid by cooling to eutectic temperatures, separating and melting crystals at slightly higher temperatures for washing, resulting in a purified phase with reduced energy use and minimal equipment complexity, enabling efficient large-scale industrial application.
Implementation Method 1
the unpurified phase is cooled to crystallize (meth)acrylic acid and water at temperatures around the eutectic point to form a suspension containing crystals and a mother liquor
Implementation Method 2
crystallization taking place at a temperature T1 in the range of Te-15°C ≤ T1 ≤ Te+3°C (Te = eutectic temperature of the unpurified phase)
Implementation Method 3
the crystals are at least partially separated from the mother liquor
Implementation Method 4
at least some of the separated crystals are melted into a melt, this melting taking place at a temperature T2 in the range of T1+3°C ≤ T2 ≤ Tm-10°C (Tm = melting point of the target product)
Implementation Method 5
part of this melt is used to wash the crystals obtained in this way
Data Source
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AI summary
The present invention relates to a method for purifying an unpurified phase, containing a target product, preferably (meth)acrylic acid, water, and at least one contamination differing from the target product and from water, to obtain a purified phase, comprising a process stage comprising the following process steps: a) the target product and water are crystallized from the unpurified phase while forming a suspension containing a mother liquor and crystals, wherein said crystallizing is carried out at a temperature T1 within the range of Te - 15°C = T1 = Te + 3°C (Te = eutectic temperature of the unpurified phase); b) the crystals are at least partially separated from the mother liquor; c) at least part of the separated crystals is melted to form a melt, wherein said melting is carried out at a temperature T2 within the range of T1 2 = T1 + 20°C; and d) at least part of the melt is returned to step b), wherein the part of the melt that is not returned is present as a purified phase. The invention further relates to a method for the production of a purified phase, containing a target product and water, a method for the production of a polymer based on (meth) acrylic acid, polymers that may be obtained by means of said method, chemical products, such as fibers or molded bodies, and the use of polymers.