Dividing Wall Distillation for Stable Methylenebis(Cyclohexylamine)
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Solution Overview
Problem
Existing methods for producing methylenebis(cyclohexylamine) face issues such as high temperature stress, longer residence time, and crystallization problems during distillation, leading to operational inefficiencies and inconsistent isomer ratios.
Innovation Solution
A process involving catalytic hydrogenation of MDA followed by catalyst separation and distillation using a dividing wall column to reduce temperature stress, residence time, and prevent crystallization, while maintaining a consistent isomer ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional distillation methods are used to separate methylenebis(cyclohexylamine), then separation can be achieved, but high temperature stress and long residence time cause crystallization and isomer ratio changes
Solution Approach 1:
The patent applies segmentation by dividing the distillation process into two separate stages: a first distillation column for initial separation and a second distillation column for final purification. This segmentation allows each column to operate under optimized temperature conditions, reducing overall temperature stress on the product while maintaining separation efficiency and isomer ratio consistency.
Solution Approach 2:
The patent introduces an intermediary approach by using a condenser system that controls the phase transition of the distillate. The condenser acts as a mediator to carefully manage the temperature at which methylenebis(cyclohexylamine) transitions from vapor to liquid phase, preventing excessive temperature stress that would cause crystallization and isomer ratio changes.
2Loss of energy
If conventional distillation is used, then separation occurs, but energy consumption is high due to prolonged heating and residence time
Solution Approach 1:
The patent segments the distillation process into two columns, each optimized for specific separation tasks. The first column handles bulk separation at lower energy input, while the second column performs final purification. This segmentation reduces total energy consumption compared to a single prolonged distillation process, as each column operates more efficiently at its designated separation stage.
Solution Approach 2:
The patent implements continuous operation of both distillation columns in series, maintaining continuous useful action throughout the separation process. This continuous operation eliminates idle time and ensures that energy input is constantly productive, improving overall energy efficiency while maintaining high separation throughput and productivity.
3Manufacturing precision
If simple filtration is used after hydrogenation, then catalyst removal is achieved, but product purification is insufficient leading to impurities in final product
Solution Approach 1:
The patent segments the purification process into multiple stages: initial filtration to remove catalyst particles, followed by two sequential distillation columns for progressive purification. This segmentation achieves high product purity by removing impurities at different stages, with each stage targeting specific types of contaminants that simple filtration cannot eliminate.
Solution Approach 2:
The patent applies preliminary action by performing catalyst filtration before the distillation process. This preliminary removal of solid catalyst particles prevents interference with the distillation operation and protects the distillation columns from fouling, enabling the subsequent distillation stages to focus on molecular separation and achieve high product purity more effectively.
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 more efficient separation of methylenebis(cyclohexylamine) with reduced energy consumption and higher product purity, minimizing crystallization and maintaining isomer ratios, thus improving operational efficiency and product quality.
Implementation Method 1
catalytic hydrogenation of MDA
Implementation Method 2
hydrogenation of MDA
Implementation Method 3
subsequent distillation of the hydrogenation product using a dividing wall column
Data Source
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AI summary
The present invention relates to a process for the production of methylenebis(cyclohexylamine) comprising 1) catalytic hydrogenation of MDA, 2) separation of the catalyst and 3) subsequent distillation of the hydrogenation product, wherein at least one dividing wall column is used in step 3).