Amorphous Phosphate Catalysts for Selective Hydroxypropionic Acid Dehydration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for converting hydroxypropionic acid or its derivatives to acrylic acid suffer from low yield and selectivity, significant formation of undesired side products, long residence times, and catalyst deactivation, making them commercially non-viable.
Innovation Solution
A method using amorphous phosphate salts, such as partially dehydrated dihydrogen monophosphates of monovalent cations, in the presence of water vapor at elevated partial pressure and temperature, to catalyze the dehydration of hydroxypropionic acid to acrylic acid, maintaining Brønsted acid sites for high yield and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional catalysts (sulfate salts, phosphate salts, metal oxides, zeolites) are used for dehydration, then dehydration activity is achieved, but yield and selectivity to acrylic acid remain low with significant side product formation
Solution Approach 1:
The invention changes the chemical composition parameters of the catalyst by using amorphous phosphate salts with specific cations (alkali metals, alkaline earth metals, or transition metals) in combination with water vapor at controlled partial pressures, achieving high yield (≥80%) and selectivity (≥90%) to acrylic acid while minimizing side products
Solution Approach 2:
The invention creates a composite catalytic system combining amorphous phosphate salts with water vapor under elevated partial pressure conditions, where the interaction between the phosphate salt framework and water molecules generates enhanced Brønsted acid sites that improve both yield and selectivity
2Productivity
If conventional dehydration conditions are used, then conversion occurs, but residence time is long and catalyst deactivates
Solution Approach 1:
The invention optimizes reaction parameters including water partial pressure (≥0.5 bar, preferably ≥1 bar), temperature (200-400°C), and space velocity to achieve short residence times (≤5 seconds) while maintaining catalyst stability and preventing deactivation through the unique amorphous phosphate salt structure
Solution Approach 2:
The amorphous phosphate salt catalyst maintains its own structural integrity and catalytic activity through the presence of water vapor, which prevents catalyst deactivation by maintaining the amorphous structure and regenerating active sites, enabling prolonged catalyst longevity without external intervention
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
The method achieves high yield and selectivity for acrylic acid with minimal side products, efficient performance in short residence times, and prolonged catalyst longevity.
Implementation Method 1
A method using amorphous phosphate salts, such as partially dehydrated dihydrogen monophosphates of monovalent cations, in the presence of water vapor at elevated partial pressure and temperature, to catalyze the dehydration of hydroxypropionic acid to acrylic acid
Implementation Method 2
catalyze the dehydration of hydroxypropionic acid to acrylic acid, maintaining Brønsted acid sites for high yield and selectivity
Data Source
Figure 1~2
AI summary
Hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof are dehydrated using a catalyst and a method to produce bio-acrylic acid, acrylic acid derivatives, or mixtures thereof. A method to produce the dehydration catalyst is also provided.