SAPO Material Selective Conversion of Acetaldehyde to Crotonaldehyde
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Solution Overview
Problem
Carbonylation processes for producing acetic acid often result in by-products such as aldehydes, which are difficult and costly to remove, with existing methods being inefficient and ineffective in selectively converting acetaldehyde to crotonaldehyde while avoiding paraldehyde formation.
Innovation Solution
Contacting methanol and carbon monoxide in the presence of a liquid reaction medium with rhodium, iridium, or palladium catalysts and water, followed by using a micro-porous silicoaluminophosphate (SAPO) material to selectively convert acetaldehyde to crotonaldehyde under specific conditions, avoiding paraldehyde formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to remove aldehyde by-products, then removal of by-products is achieved, but the process becomes difficult and costly
Solution Approach 1:
The patent changes the chemical parameters of the system by introducing a specific catalyst composition (metal complex with ligands) and controlling reaction conditions (temperature, pressure, solvent type) to enable selective conversion of acetaldehyde to crotonaldehyde. This transforms the removal process from a complex multi-step separation into a single selective chemical reaction, reducing process complexity while maintaining reliable by-product removal.
Solution Approach 2:
The patent uses crotonaldehyde as an intermediary substance. Instead of directly removing acetaldehyde through complex separation processes, the system converts acetaldehyde into crotonaldehyde using a catalyst, which then facilitates easier separation from the acetic acid product. This intermediary approach simplifies the overall process while achieving reliable by-products removal.
2Reliability
If conventional methods are used to remove aldehyde by-products, then removal of by-products is achieved, but the process becomes costly
Solution Approach 1:
The patent employs parameter changes by optimizing catalyst composition (metal choice, ligand types, catalyst concentration) and reaction conditions to achieve high conversion efficiency with minimal by-products. This reduces the need for expensive multi-step purification processes, lowering manufacturing costs while maintaining reliable by-products removal.
Solution Approach 2:
The patent converts the harmful acetaldehyde by-product into a beneficial intermediate (crotonaldehyde) that facilitates easier separation. By transforming the problematic by-product into a form that is more easily managed and separated, the process reduces overall costs while achieving reliable removal.
3Productivity
If acetaldehyde is converted to crotonaldehyde, then separation efficiency is improved, but paraldehyde formation occurs as an unwanted by-product
Solution Approach 1:
The patent applies local quality by designing a catalyst system with specific metal centers and ligand environments that create localized chemical conditions favorable for crotonaldehyde formation while unfavorable for paraldehyde formation. The catalyst structure provides specific active sites that selectivity promote the desired transformation, reducing harmful paraldehyde by-products while maintaining high separation efficiency.
Solution Approach 2:
The patent controls the reaction parameters (temperature, pressure, catalyst concentration, solvent type) to optimize the balance between crotonaldehyde formation and paraldehyde formation. By carefully adjusting these parameters, the system achieves high productivity through efficient separation while minimizing harmful paraldehyde by-products.
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
Achieves high conversion rates of acetaldehyde to crotonaldehyde (>60%) with minimal conversion to paraldehyde, facilitating efficient separation of impurities from acetic acid through distillation, thereby improving the acetic acid production process.
Implementation Method 1
contacting at least a portion of the carbonylation product or a derivative thereof with a micro-porous material to selectively convert at least a portion of the acetaldehyde to crotonaldehyde, wherein the micro-porous material includes a silicoaluminophosphate (SAPO)
Implementation Method 2
contacting methanol and carbon monoxide in the presence of a liquid reaction medium under carbonylation conditions sufficient to form a carbonylation product including acetic acid and acetaldehyde, wherein the liquid reaction medium includes: a carbonylation catalyst selected from rhodium catalysts, iridium catalysts and palladium catalysts
Implementation Method 3
facilitating efficient separation of impurities from acetic acid through distillation
Data Source
AI summary
The present technology discloses processes for producing carboxylic acid. In some embodiments, the processes include contacting methanol and carbon monoxide in the presence of a liquid reaction medium under carbonylation conditions sufficient to form a carbonylation product, including acetic acid and acetaldehyde. The liquid reaction medium may include a carbonylation catalyst selected from rhodium catalysts, iridium catalysts and palladium catalysts; and water in a water concentration in a range of 1 wt. % to 14 wt. % based on the total weight of the liquid reaction medium. In certain embodiments, the processes comprise contacting at least a portion of the carbonylation product or a derivative thereof with a micro-porous material such as a silicoaluminophosphate (SAPO) to selectively convert at least a portion of the acetaldehyde to crotonaldehyde.