Acrylic Acid Recovery via Splitting Column Segmentation

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Solution Overview

Problem

Current processes for recovering acrylic acid are energy-intensive and require significant equipment, limiting efficiency in product yield and purity.

Innovation Solution

A process involving the division of a mother acid stream into two partial streams, with one fed as reflux to a cleavage column and the other to a condensation column, along with a stripping gas stream, to separate and recycle oligomeric acrylic acid into monomeric form, enhancing yield and purity by countercurrent rectification and heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional processes are used for recovering acrylic acid, then the separation and purification can be achieved, but the energy consumption is high and equipment requirements are significant

Engineering Contradiction:
Improveenergy consumptionVSAvoidyield and purity of acrylic acid
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The mother acid stream is divided into two partial streams: one is fed as reflux to the cleavage column and the other to the condensation column. This segmentation allows optimized processing in each column, reducing overall energy consumption while maintaining high yield and purity through specialized function distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mother acid stream is pre-heated to 50-100°C before division and processing. This preliminary heating reduces the energy required during subsequent separation and purification steps in both the cleavage and condensation columns, addressing the energy consumption issue while maintaining process efficiency.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If the mother acid stream is processed without division, then the process is simpler, but the yield and purity of acrylic acid are reduced

Engineering Contradiction:
Improveprocess complexityVSAvoidyield and purity of acrylic acid
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The mother acid stream is divided into two partial streams that are processed separately in different columns. This segmentation increases yield and purity by allowing optimized processing conditions in each column while keeping the overall process structure relatively simple through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The divided mother acid partial streams serve different functions: one stream is processed in the cleavage column for oligomer breakdown while the other is processed in the condensation column for purification. This multi-functionality approach maximizes yield and purity without requiring excessively complex equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If oligomeric acrylic acid is not separated and recycled, then the process is more straightforward, but the yield of desired product decreases

Engineering Contradiction:
Improveequipment requirementsVSAvoidyield of acrylic acid
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The process separates oligomeric acrylic acid handling into a dedicated cleavage column while maintaining a separate condensation column for purification. This segmentation enables effective oligomer recycling that increases yield without requiring overly complex integrated equipment systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Oligomeric acrylic acid is separated from the mother acid stream and fed to the cleavage column where it is broken down and recycled back into the process. This recovery approach increases the overall yield of acrylic acid by converting oligomers back to monomer form without significantly increasing equipment complexity.

Inventive Principle:
Principle #34Discarding and recovering

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 increases the yield and purity of acrylic acid by efficiently breaking down secondary components and reducing energy expenditure, with improved equipment utilization and reduced work-up loss.

Implementation Method 1

separating the secondary components contained in the secondary component stream by countercurrent rectification in the attached cleavage column

Methodology Applied
Scientific EffectCountercurrent rectification: Distillation

Implementation Method 2

dividing a mother acid stream from a crystallization device, which has been heated to a temperature of 50° C. to 100° C., into a first and a second mother acid partial stream

Methodology Applied
Scientific EffectThermal energy management: Heating

Implementation Method 3

fractional condensation of the product gas mixture of a gas-phase catalytic oxidative production

Methodology Applied
Scientific EffectFractional condensation: Condensation

Data Source

PatentEP3201167B1Method and system for recovering acrylic acid
Publication Date: 2020.08.05 BASF SE
  • EP3201167B1 patent drawingFigure 1

AI summary

The invention relates to a method for recovering acrylic acid, having the following steps a) separating a temperature-controlled mother acid stream from a crystallization device in the direction of an absorption column (201) and in the direction of a splitting column (205), b) supplying the first temperature-controlled mother acid sub-stream as a return flow to the top plate of the splitting column (205), c) supplying at least one strip gas stream below the bottom plate of the splitting column (205), d) supplying an auxiliary component stream, which comprises an oligomeric acrylic acid, from the condensation column (201) to a central base of the splitting column (205), e) splitting at least one part of the oligomeric acrylic acid from the auxiliary component stream in the splitting column (205), thereby obtaining monomeric acrylic acid, f) separating the auxiliary components contained in the auxiliary component stream by means of a counter-current rectification process in the splitting column (205), g) discharging the monomeric acrylic acid without condensation as a gas mixture together with the supplied strip circuit gas stream at the head of the splitting column (205), and h) supplying the gas mixture below the bottom plate of the condensation column (201). The invention further relates to a system (1) for recovering acrylic acid.