Laurolactam Purification via Melt Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for purifying crude lactam mixtures, particularly those containing laurolactam, face challenges due to high boiling points leading to thermal stress and decomposition during distillation, resulting in reduced yield and purity.
Innovation Solution
The method employs controlled melt crystallization, specifically layer or suspension crystallization, to selectively crystallize laurolactam, reducing thermal stress by lowering the process temperature and minimizing thermal separating steps, allowing for the separation of laurolactam from secondary components with enhanced purity and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multistage distillation is used to remove laurolactam from crude mixture, then separation efficiency is improved, but thermal stress causes material decomposition and yield reduction
Solution Approach 1:
The invention changes the fundamental separation parameter from thermal vaporization (distillation) to solid-liquid phase separation (crystallization). By controlling the temperature to induce crystallization of laurolactam at lower temperatures, the process avoids high-temperature thermal stress while achieving effective separation from secondary components through selective crystallization and filtration.
Solution Approach 2:
The invention utilizes phase transition from liquid to solid through controlled crystallization. By cooling the crude lactam mixture to temperatures where laurolactam crystallizes selectively, the process separates the target component from the liquid mother liquor containing secondary components, eliminating the need for high-temperature distillation and its associated thermal decomposition.
2Manufacturing precision
If high vacuum distillation is applied due to high boiling point of laurolactam, then separation is achieved, but thermal stress leads to decomposition
Solution Approach 1:
The invention changes the separation mechanism from vapor-phase (distillation requiring high temperature and vacuum) to solid-phase (crystallization at lower temperatures). This parameter change eliminates thermal stress as the primary separation driver, using instead temperature-controlled crystallization to achieve high purity without thermal decomposition.
Solution Approach 2:
The invention replaces the mechanical/thermal system of vacuum distillation with a thermal field-based crystallization system. Instead of using vacuum and high temperature to achieve separation, the process uses controlled temperature reduction to induce crystallization, substituting thermal vaporization with solid formation to eliminate harmful thermal stress.
3Productivity
If multiple evaporation steps are used in distillation, then separation is improved, but cumulative thermal stress reduces overall yield
Solution Approach 1:
The invention segments the separation process into distinct stages: crystallization of laurolactam, filtration of crystals from mother liquor, and optional recrystallization. This segmentation replaces multiple cumulative evaporation steps with a more efficient single-stage crystallization process, reducing total thermal exposure while maintaining separation efficiency.
Solution Approach 2:
The invention maintains continuous useful action through controlled crystallization where laurolactam continuously forms crystals as the mixture cools, followed by continuous filtration. This continuous process replaces discontinuous evaporation steps, ensuring maximum recovery of the target component while minimizing thermal stress accumulation.
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 approach reduces thermal decomposition, eliminates the need for high vacuum distillation, lowers energy costs, and simplifies the process by achieving high selectivity and purity with fewer steps, while maintaining the quality of the target product.
Implementation Method 1
selectively crystallizing laurolactam present in said crude lactam mixture by melt crystallization through controlled cooling of said crude lactam mixture
Implementation Method 2
controlled increase in the wall temperature to partially melt a crystal layer which contains the laurolactam and intercalated secondary components to sweat adhering secondary components out of the crystal layer
Implementation Method 3
the movement of the melt is generated on the inside of a cooled tube by means of a trickle film
Implementation Method 4
the movement of the melt is generated on the outside of a cooled tube by means of a trickle film
Implementation Method 5
particles generated during said suspension crystallization are removed from the mother liquor by a solid/liquid separation and are washed with a molten product
Data Source
AI summary
The present invention provides a method for purifying laurolactam from a crude lactam mixture. In the method of the present invention, laurolactam is selectively crystallized by melt crystallization with controlled cooling of the crude lactam mixture.