Bio-based Acrylic Acid Purification via Extraction and Crystallization
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Solution Overview
Problem
There is a need for commercially viable processes to purify bio-based acrylic acid produced from the dehydration of hydroxypropionic acid or its derivatives to achieve high purity levels comparable to petroleum-based acrylic acid, as existing methods do not effectively remove impurities to meet industrial standards for applications such as superabsorbent polymers and water treatment.
Innovation Solution
The process involves a series of steps including extraction, drying, distillation, cooling, partial melting, and decanting to produce glacial acrylic acid with at least 98 wt% purity, using a catalyst system comprising monohydrogen and dihydrogen monophosphate anions with specific cations, and employing solvents like ethyl acetate to remove impurities like lactic acid and propanoic acid, while maintaining a high bio-based content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multistage distillations and extraction steps are employed to remove side products from petroleum-based acrylic acid, then purity of acrylic acid is improved, but process complexity and cost increase
Solution Approach 1:
The patent employs liquid-liquid extraction using water as an extracting solvent to selectively remove impurities (aldehydes, carboxylic acids, and other side products) from the acrylic acid reaction mixture. This extraction step efficiently separates impurities into the aqueous phase while maintaining acrylic acid in the organic phase, achieving high purity without requiring complex multistage distillation systems.
2Manufacturing precision
If multistage distillations are used to purify acrylic acid to glacial purity levels, then purity is improved, but energy consumption increases
Solution Approach 1:
The patent introduces water as an intermediary extracting solvent that selectively partitions impurities from the acrylic acid mixture. This intermediary extraction step performs the purification function that would otherwise require energy-intensive distillation, significantly reducing energy consumption while achieving glacial purity levels (≥98% acrylic acid).
3Manufacturing precision
If conventional purification methods are used for bio-based acrylic acid, then impurity removal is improved, but bio-based content is reduced due to loss of renewable material
Solution Approach 1:
The patent converts the typically harmful effect of water (which can cause polymerization of acrylic acid) into a beneficial extracting solvent. Water selectively dissolves and removes impurities such as aldehydes and carboxylic acids from the bio-based acrylic acid mixture, achieving effective purification while preserving the bio-based content since water extraction does not cause the substantial material losses associated with conventional distillation methods.
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 method effectively purifies bio-based acrylic acid to glacial purity levels, reducing impurities to less than 2 wt% and achieving a bio-based content greater than 3%, enabling its use in high-performance applications while minimizing environmental impact by utilizing renewable resources.
Implementation Method 1
using a catalyst system comprising monohydrogen and dihydrogen monophosphate anions with specific cations
Implementation Method 2
employing solvents like ethyl acetate to remove impurities like lactic acid and propanoic acid
Implementation Method 3
The process involves a series of steps including extraction, drying, distillation, cooling, partial melting, and decanting
Implementation Method 4
cooling, partial melting, and decanting to produce glacial acrylic acid with at least 98 wt% purity
Data Source
AI summary
Processes for the purification of bio-based acrylic acid to crude and glacial acrylic acid are provided. The bio-based acrylic acid is produced from hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof. The purification includes some or all of the following processes: extraction, drying, distillation, and melt crystallization. The produced glacial or crude acrylic acid contains hydroxypropionic, hydroxypropionic acid derivatives, or mixtures thereof as an impurity.