Conjugated Diene Production via Liquid Phase Dehydration
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Solution Overview
Problem
Current methods for producing conjugated dienes have low selectivity and high production costs due to the need for high temperatures and energy-intensive dehydration processes, which can lead to decomposition and inefficiencies.
Innovation Solution
A two-stage process involving the reaction of α-olefin and formaldehyde to produce γ,δ-unsaturated alcohol, followed by a dehydration reaction at 135 to 210°C in the presence of an acidic catalyst, with continuous feeding and intermittent removal of reactants and products, optimizing reaction conditions to enhance selectivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If vapor phase dehydration is performed at high temperatures to vaporize the raw material, then the dehydration reaction can proceed, but a large quantity of heat source is required and decomposition of the γ,δ-unsaturated alcohol may occur
Solution Approach 1:
The invention changes the physical state parameter of the reaction system from vapor phase to liquid phase, allowing the dehydration reaction to proceed at lower temperatures (100-180°C) without requiring vaporization of the raw material, thereby reducing heat source requirements and preventing decomposition
Solution Approach 2:
The invention introduces an acidic catalyst as an intermediary substance that enables the dehydration reaction to proceed efficiently at lower temperatures in the liquid phase, eliminating the need for high temperature vaporization while maintaining reaction effectiveness
2Temperature
If vapor phase dehydration is performed under reduced pressure to vaporize the raw material, then the dehydration reaction can proceed, but the method cannot be immediately applied from the industrial viewpoint due to complexity
Solution Approach 1:
The invention changes the pressure parameter from reduced pressure to atmospheric or elevated pressure, and changes the phase from vapor to liquid, simplifying the equipment requirements and making the process immediately applicable to industrial continuous production without complex vacuum systems
3Device complexity
If a one-stage reaction from α-olefin and formaldehyde is used to produce conjugated diene, then the production process is simple, but the selectivity of isoprene is low at about 73% and production amount of high boiling point byproducts is high
Solution Approach 1:
The invention segments the one-stage reaction into two distinct stages: first producing γ,δ-unsaturated alcohol from α-olefin and formaldehyde with high selectivity, then dehydrating it to produce conjugated diene. This segmentation improves overall selectivity while maintaining industrial applicability through continuous processing
4Use of energy by moving object
If liquid phase dehydration is performed at lower reaction temperatures, then energy consumption is reduced, but the disclosed method cannot be immediately applied from the industrial viewpoint due to lack of continuous reaction method description
Solution Approach 1:
The invention implements continuous liquid phase dehydration where γ,δ-unsaturated alcohol and water are continuously fed into the reactor and the produced conjugated diene and water are continuously removed, enabling industrial-scale production at lower temperatures with improved energy efficiency and manufacturability
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 achieves high selectivity and stability in producing conjugated dienes, reducing energy consumption and minimizing byproduct formation, thus improving industrial viability.
Implementation Method 1
subjecting the γ,δ-unsaturated alcohol to a dehydration reaction at 135 to 210° C. in the presence of an aqueous solution of an acidic catalyst
Data Source
AI summary
A method for producing a conjugated diene, including a step A of allowing an α-olefin and formaldehyde to react with each other to produce a γ,δ-unsaturated alcohol in the presence of an alcohol; and a step B of subjecting the γ,δ-unsaturated alcohol to a dehydration reaction at 135 to 210° C. in the presence of an aqueous solution of an acidic catalyst.