Dynamic Melt Crystallization for Dicyclopentadiene Purification
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Solution Overview
Problem
Conventional processes for purifying dicyclopentadiene from mixed liquid hydrocarbon streams are energy-intensive and inefficient, particularly in achieving high purities due to small boiling point differences between co-dimers and trimer impurities, making it challenging to achieve purities above 94% using fractional distillation.
Innovation Solution
A dynamic method involving melt crystallization, sweating, and recycling of impure crystalline phases to separate and purify dicyclopentadiene, where the mixed liquid hydrocarbon stream is divided and contacted with the inner wall of a separation/purification unit to form an impure crystalline slurry, followed by sweating to partially melt and separate dicyclopentadiene crystals from impurities, with optional multiple stages and auxiliary separation units for enhanced purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fractional distillation is used to separate dicyclopentadiene from co-dimers and trimers, then separation is achieved based on boiling point differences, but the small boiling point differences make it very energy intensive to achieve purities above 94%
Solution Approach 1:
The patent changes the separation parameter from boiling point (distillation) to melting point (crystallization). By cooling the mixture to temperatures below the melting point of dicyclopentadiene (approximately 33.6°C), the desired compound crystallizes while impurities remain in the liquid phase, enabling high purity separation without energy-intensive heating
Solution Approach 2:
The patent utilizes the phase transition of dicyclopentadiene from liquid to solid through controlled cooling and crystallization. The compound is cooled to form crystals, then melted to separate pure dicyclopentadiene from impurities, leveraging phase changes rather than relying on boiling point differences
2Manufacturing precision
If conventional distillation processes operate at high temperatures of 150°C to 250°C, then separation of hydrocarbon components is achieved, but the processes become very energy intensive
Solution Approach 1:
The patent fundamentally changes the operating temperature parameter from high (150-250°C distillation) to low (below 33.6°C crystallization). This parameter change enables separation based on melting point differences rather than boiling point differences, dramatically reducing energy consumption while maintaining separation efficiency
Solution Approach 2:
The patent replaces the thermal field (heating and vaporization) with a thermal field operating in reverse (cooling and crystallization). Instead of using heat to vaporize and condense components, the process uses controlled cooling to induce crystallization, substituting a high-energy thermal process with a low-energy thermal process
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 reduces energy consumption and achieves higher purity dicyclopentadiene with lower operational temperatures, requiring simpler and less costly equipment, while minimizing thermal degradations and byproduct formation, and can produce dicyclopentadiene with purities exceeding 99%.
Implementation Method 1
continuously contacting the plurality of mixed liquid hydrocarbon streams with an inner wall of the separation/purification unit to form an impure crystalline slurry comprising an impure crystalline phase, and an excess liquid phase, wherein dicyclopentadiene crystals are present in the impure crystalline phase
Implementation Method 2
sweating the impure crystalline phase at least once to a sweating temperature to at least partially melt the impure crystalline phase and/or an low melting impurity present in the impure crystalline phase to form a purified crystalline phase comprising the dicyclopentadiene crystals and a molten impurity phase
Data Source
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AI summary
A dynamic process for purifying dicyclopentadiene from a mixed liquid hydrocarbon stream comprising dicyclopentadiene and one or more of a C5 paraffin, a C5 olefin, co-dimers, cyclopentadiene, benzene, vinyl norbornene, bicyclononadiene, propenyl noibornene, isopropenyl norbornene, methylbicyclononadiene, methyldicyclopentadiene, and various minor organic impurities is introduced, wherein the dicyclopentadiene is separated from the mixed liquid hydrocarbon stream by melt crystallizing sweating and collecting dicyclopentadiene.