Lactic Acid Dehydration Control Using NIR for Acrylic Acid Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing acrylic acid from lactic acid face challenges such as incorrect measurement of lactic acid content, formation of oligomers, and catalyst deactivation due to by-products like propanoic acid, leading to reduced catalyst lifespan and increased costs.
Innovation Solution
A method involving real-time analysis of reaction products using a near-infrared spectrometer to monitor lactic acid, its derivatives, and propanoic acid concentrations, allowing for precise control of reaction temperature and catalyst regeneration, using a dedicated apparatus with a reaction unit, discharge unit, absorption tower, and near-infrared spectrometer for continuous monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If lactic acid dehydration is performed at high temperature (300°C or higher) to produce acrylic acid, then the dehydration reaction efficiency is improved, but lactic acid forms oligomers and measurement accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by performing measurement correction in advance based on the known relationship between measurement values and actual values. The correction value is calculated beforehand using the formula: correction value = measurement value × correction coefficient, where the correction coefficient is determined from the ratio of actual lactic acid content to measured lactic acid content. This preliminary correction enables accurate measurement despite the high-temperature conditions that cause oligomer formation.
2Productivity
If propanoic acid is produced as a by-product during lactic acid dehydration, then the dehydration reaction proceeds, but coke forms on the catalyst surface reducing catalyst lifespan
Solution Approach 1:
The patent implements feedback control by continuously monitoring the concentration of propanoic acid in the reaction mixture and using this information to adjust reaction conditions. When propanoic acid concentration exceeds a predetermined threshold, the system automatically adjusts parameters such as temperature, pressure, or feed rate to prevent excessive coke formation. This closed-loop feedback mechanism maintains catalyst activity and extends catalyst lifespan while preserving acrylic acid production efficiency.
3Device complexity
If traditional measurement methods are used to analyze lactic acid content, then the analysis process is simple, but the measurement time is long and results are inaccurate due to oligomer formation
Solution Approach 1:
The patent replaces traditional mechanical/chemical measurement methods with near-infrared (NIR) spectroscopy. Instead of using time-consuming techniques like gas chromatography or liquid chromatography that require sample preparation and separation, the system uses NIR spectrometry to directly measure lactic acid content in the reaction mixture. This substitution of measurement mechanism provides rapid, real-time analysis without the time loss and accuracy problems associated with traditional methods.
4Ease of manufacture
If propylene oxidation method is used to produce acrylic acid, then the production process is established, but acetic acid by-product is difficult to separate and raw material costs increase
Solution Approach 1:
The patent applies parameter changes by fundamentally altering the chemical reaction pathway from propylene oxidation to lactic acid dehydration. This parameter change in the reaction mechanism eliminates the formation of acetic acid by-product that is difficult to separate. Additionally, the use of renewable lactic acid feedstock from biomass changes the raw material parameter from fossil-based propylene to sustainable lactic acid, reducing both separation issues and raw material costs associated with crude oil refining.
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
Enables accurate and timely adjustment of reaction conditions, maintaining catalyst efficiency and yield of acrylic acid, reducing energy consumption, and minimizing by-product formation.
Implementation Method 1
analyzing in real time the concentrations of lactic acid, lactic acid derivatives including lactic acid oligomers, acrylic acid, and propanoic acid in the liquid mixture using a near-infrared spectrometer
Implementation Method 2
preparing a liquid mixture by condensing the reaction products
Data Source
Figure 1~2
AI summary
Provided are a method for producing an acrylic acid through dehydration of lactic acid, and an apparatus for manufacturing the same.