Acrylic Acid Crystallization Water Concentration Control

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Solution Overview

Problem

Existing methods for producing acrylic acid face challenges in maintaining high purity and yield, especially during unsteady states characterized by high water concentrations in the acrylic acid-containing solution, leading to reduced yield and increased costs due to additional water separation operations.

Innovation Solution

The method involves mixing the acrylic acid-containing solution with purified acrylic acid or a solution containing 10 mass % or less water to adjust the water concentration to 10 mass % or less, allowing for smooth crystallization and production of high-purity acrylic acid, even when the initial solution has more than 10 mass % water, and using the high-water solution as an absorption liquid to circulate and dilute it appropriately.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the acrylic acid-containing solution is directly subjected to crystallization process, then the production process is easy and simple, but when the concentration of water is high, the crystallization process cannot be carried out smoothly and the yield is lower

Engineering Contradiction:
Improveease of production processVSAvoidyield of acrylic acid
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The invention changes the water concentration parameter of the acrylic acid-containing solution from above 10 mass% to 10 mass% or less by mixing with a solution having low water concentration, thereby enabling smooth crystallization and improving both ease of manufacture and productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces an intermediary solution having low water concentration (10 mass% or less) as a mediator to mix with the high-water-concentration solution, transforming it into a suitable feed for crystallization without requiring complex water separation operations

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the acrylic acid-containing solution with high water concentration is subjected to water separation operation, then the concentration of water can be lowered, but the cost increases and the yield is lowered

Engineering Contradiction:
Improveconcentration of waterVSAvoidyield of acrylic acid
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

Instead of using complex water separation operations, the invention uses a low-water-concentration solution as an intermediary to dilute the high-water-concentration solution, achieving the desired water concentration while minimizing acrylic acid loss and cost increase

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the acrylic acid-containing solution with high water concentration is disposed of, then the operational complexity is reduced, but the yield of acrylic acid is lowered

Engineering Contradiction:
Improveoperational complexityVSAvoidyield of acrylic acid
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention converts the harmful high-water-concentration solution that would otherwise need to be disposed of into a useful feed stream by mixing it with a low-water-concentration solution, thereby improving yield while maintaining operational simplicity

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 approach enables the production of high-purity acrylic acid in good yield without increasing costs, by ensuring the crystallization process can proceed smoothly and efficiently, even in unsteady states, and reduces losses and operational complexities.

Implementation Method 1

subjecting the (meth)acrylic acid-containing solution to a crystallization process

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 2

a method in which an acrylic acid-containing gas is brought in contact with an aqueous solution for absorption in an absorption column

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP1903025B1Method for producing (meth)acrylic acid
Publication Date: 2011.03.09 NIPPON SHOKUBAI CO LTD
  • EP1903025B1 patent drawingFigure 1

AI summary

In a production method in which an acrylic acid-containing solution obtained from an acrylic acid-containing gas (or an acrylic acid-containing liquid obtained simply by subjecting the acrylic acid-containing solution to a separation process of reaction by-products) is directly subjected to a crystallization process, the crystallization process can't be carried out smoothly in an unsteady state (when the concentration of water in the acrylic acid-containing solution is high). The present invention aims to provide a method for collecting the purified acrylic acid having high purity in good yield even in an unsteady state. When the acrylic acid-containing solutions 18 and 16 have a concentration of water higher than 10 mass % (unsteady state), the purified acrylic acid 20 and 22 or the acrylic acid-containing solution 23 containing 10 mass % or less of water is mixed therewith to make the concentration of water 10 mass % or less[a][b]. Alternatively, when the acrylic acid-containing solutions 18 and 16 have a concentration of water higher than 10 mass %, it is used as an absorption liquid [c]. Thereafter, the crystallization process is carried out.