Recycled Polymer Precipitation Using a Single Circulating Solvent
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for recycling polymers from waste resins consume excessive energy due to the need for solvent removal processes, particularly when using different solvents for dissolution and recrystallization, and require separate separation processes for solvent reuse.
Innovation Solution
A method using cycloalkyl alkyl ether as a single solvent in both dissolution and precipitation tanks, where the polymer is dissolved at a high temperature above its boiling point and then precipitated at a lower temperature in a separate tank, minimizing solvent residual amounts and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If different solvents are used for dissolution and recrystallization, then polymer precipitation efficiency is improved, but device complexity and energy consumption increase due to separate solvent separation processes
Solution Approach 1:
The patent merges the dissolution and recrystallization steps by using the same solvent (cycloalkyl alkyl ether) for both processes. The solvent is circulated from the dissolution tank to the recrystallization tank and back, eliminating the need for separate solvent separation equipment and reducing device complexity while maintaining high polymer precipitation efficiency.
Solution Approach 2:
The cycloalkyl alkyl ether solvent serves multiple functions: it acts as both the dissolution solvent and the recrystallization solvent, and also functions as a circulating medium that transfers polymer solution between tanks. This multi-functionality eliminates the need for separate solvent handling systems for different process stages.
2Manufacturing precision
If polymer solution is cooled for precipitation, then recrystallization is achieved, but energy consumption increases due to additional solvent removal processes
Solution Approach 1:
The patent changes the temperature parameter of the solvent to control polymer solubility. By cooling the cycloalkyl alkyl ether solvent in the recrystallization tank, the polymer precipitates due to reduced solubility at lower temperatures. This parameter change achieves purification without requiring additional solvent removal processes, as the low-boiling-point solvent evaporates easily.
Solution Approach 2:
The patent utilizes the phase transition of the solvent from liquid to vapor due to its low boiling point. The cycloalkyl alkyl ether solvent naturally evaporates after the precipitation process, eliminating the need for energy-intensive forced solvent removal while maintaining high polymer purity through the precipitation step.
3Productivity
If antisolvent is used for polymer precipitation, then polymer recovery is improved, but solvent separation complexity increases for reusing solvents
Solution Approach 1:
The patent combines the functions of dissolution solvent and precipitation solvent by using the same cycloalkyl alkyl ether in both tanks. The solvent circulates between dissolution and recrystallization stages, eliminating the need for antisolvent addition and subsequent solvent separation systems, thereby simplifying the overall process while maintaining effective polymer recovery.
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 enhances polymer precipitation efficiency, reduces energy use, simplifies the process by eliminating the need for solvent separation, and allows for direct reuse of the solvent, thereby lowering costs and environmental impact.
Implementation Method 1
heating to a dissolution temperature and dissolving a polymer included in the composite resin while maintaining the dissolution tank at the dissolution temperature
Implementation Method 2
dissolving a polymer included in the composite resin while maintaining the dissolution tank at the dissolution temperature to obtain a polymer solution
Implementation Method 3
supplying the polymer solution to a precipitation tank in which the solvent is maintained at a precipitation temperature and precipitating the polymer
Implementation Method 4
precipitating the polymer included in the polymer solution to obtain a solution including a polymer precipitate
Implementation Method 5
the polymer solution is brought into contact with an antisolvent to recrystallize the solution
Data Source
AI summary
Provided is a method of preparing a recycled polymer including: (S1) supplying cycloalkyl alkyl ether as a solvent to a dissolution tank and a precipitation tank, respectively; (S2) supplying a composite resin to the dissolution tank, heating to a dissolution temperature, and dissolving a polymer included in the composite resin while maintaining the dissolution tank at the dissolution temperature to obtain a polymer solution; (S3) supplying the polymer solution to the precipitation tank in which the solvent is maintained at a precipitation temperature and precipitating the polymer included in the polymer solution to obtain a solution including a polymer precipitate; and (S4) filtering the solution including the polymer precipitate to obtain the polymer precipitate.