Mixed Phosphate Catalyst for Lactic Acid Dehydration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for converting lactic acid to acrylic acid result in high amounts of undesired by-products, leading to catalyst fouling, premature deactivation, and increased production costs due to the need for complex purification processes, making them non-viable commercially.
Innovation Solution
A mixed phosphate catalyst comprising at least two different phosphate salts, specifically selected from certain formulas, is used in the catalytic dehydration of lactic acid to produce acrylic acid with high molar yield and selectivity, while minimizing by-products, and is characterized by a surface acidity density of 0.35 mmol/m² or less and a surface basicity density of at least 2 mmol/m².
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional acidic catalysts are used to convert lactic acid to acrylic acid, then conversion can be achieved, but high amounts of undesired by-products are formed leading to catalyst fouling and premature deactivation
Solution Approach 1:
The patent fundamentally changes the catalyst's chemical properties by using basic catalysts (alkali metal hydroxides, carbonates, or bicarbonates) instead of conventional acidic catalysts. This parameter change in catalyst acidity/basicity transforms the reaction mechanism to minimize by-product formation while maintaining high acrylic acid yield, directly resolving the contradiction between productivity and catalyst reliability
Solution Approach 2:
The patent employs composite catalyst systems combining basic catalysts with specific carriers (such as alumina, silica, or magnesia) to create a composite material that enhances both activity and stability. The carrier provides structural support and additional basic sites, improving catalyst reliability while maintaining high productivity
2Manufacturing precision
If conventional purification methods are used to remove by-products, then acrylic acid purity can be achieved, but production costs increase due to complex multi-stage processes
Solution Approach 1:
The patent converts the harmful effect of by-product formation into a benefit by using basic catalysts that inherently suppress unwanted side reactions. The basic catalyst environment prevents decarbonylation and decarboxylation reactions that produce impurities, turning what would be a purification problem into a prevention solution, thereby achieving high purity without complex processing
Solution Approach 2:
The patent extracts and eliminates the source of the problem by removing acidic catalysts that promote by-product formation. By taking out the harmful acidic component and replacing it with basic catalysts, the need for complex purification stages is eliminated, achieving both high purity and simplified manufacturing
3Productivity
If contact time is increased to improve acrylic acid yield, then molar yield increases, but the process becomes impractical for commercial manufacturing
Solution Approach 1:
The patent changes the reaction parameters by using basic catalysts that enable high acrylic acid yields at significantly reduced contact times. The basic catalyst system accelerates the desired dehydration reaction while suppressing side reactions, allowing commercial-scale operation with practical residence times while maintaining high molar yields
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 process achieves a high molar yield and selectivity for acrylic acid, reducing the formation of undesired by-products, thus eliminating the need for complex purification and enhancing the stability and efficiency of the catalyst, making the process commercially viable.
Implementation Method 1
a mixed phosphate catalyst that includes at least two different phosphate salts... in the catalytic dehydration of lactic acid to produce acrylic acid
Implementation Method 2
characterized by a surface acidity density of 0.35 mmol/m² or less and a surface basicity density of at least 2 mmol/m²
Data Source
Figure 1
AI summary
Disclosed herein is the catalytic dehydration of lactic acid to acrylic acid, which is characterized by a high conversion of lactic acid, a high selectivity for acrylic acid, a high yield of acrylic acid, and correspondingly low selectivity and molar yields for undesired by-products. This is achieved with a particular class of catalysts defined by a mixture of metal-containing phosphate salts that together provide the catalyst with a very high basicity density and low acidity density. Further, the catalyst is believed to be stable and active for lengthy periods heretofore unseen in the art for such dehydration processes.