Halogenated Polymer Recycling via Solvent Phase Separation
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Solution Overview
Problem
Current methods for recycling halogenated polymers, such as PVC, face challenges including the need for efficient removal of heavy metals like Pb and Cd to comply with REACh regulations, especially for mechanical recycling, and the difficulty in reusing solvents without extensive separation processes.
Innovation Solution
A process involving mixing ground halogenated polymer materials with a solvent to create a continuous and discontinuous phase, separating and evaporating the solvent to produce a halogenated polymer product with reduced heavy metal content, which can then be reused or directly processed into new polymer articles, allowing for the recycling of rigid PVC articles and compliance with REACh regulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heavy metals are removed from halogenated polymers to comply with REACh regulations, then the polymer can be recycled mechanically, but the removal process is complex and requires multiple separation steps
Solution Approach 1:
The patent segments the removal process into distinct phases: dissolving the polymer in a solvent, separating the solution from insoluble heavy metal compounds, and evaporating the solvent. This segmentation allows each step to be optimized independently and simplifies the overall process compared to attempting complete removal in a single complex operation.
Solution Approach 2:
The patent extracts heavy metal compounds from the polymer matrix through selective dissolution. By choosing a solvent that dissolves the polymer but leaves heavy metal compounds insoluble, the method selectively removes the harmful substances while preserving the polymer material, enabling compliance with REACh regulations.
2Ease of manufacture
If a solvent is used to dissolve halogenated polymer for processing, then the polymer can be treated and heavy metals removed, but the solvent requires extensive separation and reprocessing
Solution Approach 1:
The patent applies self-service by evaporating the solvent to recover it in its original form, which can then be reused in the dissolution step without extensive separation or reprocessing. This closes the solvent loop and eliminates the need for complex solvent recovery operations, significantly reducing time and resource losses.
Solution Approach 2:
The patent utilizes phase transition (evaporation) to separate the solvent from the treated polymer. By evaporating the solvent, it transitions from liquid to gas and can be condensed and reused, providing a simple and efficient method to recover the solvent without requiring complex separation equipment or extensive processing time.
3Use of energy by moving object
If mechanical recycling is used for halogenated polymer articles, then the process is cost and energy efficient, but heavy metals must be removed to comply with future REACh regulations
Solution Approach 1:
The patent applies preliminary action by removing heavy metals from the polymer before the mechanical recycling process. The polymer is dissolved, heavy metal compounds are separated, and the polymer is recovered and stabilized before being fed into the mechanical recycling line. This ensures that the energy-efficient mechanical recycling process receives material that is already compliant with REACh regulations.
Solution Approach 2:
The patent changes the physical and chemical parameters of the polymer by dissolving it in a solvent, which alters its state from solid to solution. This parameter change enables the heavy metal removal process to proceed effectively, and after evaporation and stabilization, the polymer is ready for mechanical recycling with reduced heavy metal content.
4Adaptability or versatility
If rigid PVC articles are recycled, then the recycling process can address a major polymer category, but current methods do not support rigid PVC recycling
Solution Approach 1:
The patent creates a universal treatment process that can handle different types of halogenated polymers, including rigid PVC, flexible PVC, and other formulations. By using a solvent-based dissolution approach followed by general separation and evaporation steps, the method provides multi-functional applicability across various polymer types, making rigid PVC recycling feasible.
Solution Approach 2:
The patent introduces dynamic processing steps including dissolution, separation, and evaporation that can be adjusted to handle the specific characteristics of rigid PVC. The process parameters (temperature, solvent type, evaporation conditions) can be optimized dynamically to accommodate the rigidity and processing challenges of rigid PVC articles.
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 process effectively reduces heavy metal content in halogenated polymers, enabling their recycling and reuse, while minimizing solvent reprocessing steps, thus facilitating the recycling of halogenated polymers in compliance with REACh regulations and allowing for the production of new polymer articles.
Implementation Method 1
mixing a ground halogenated polymer starting material with a solvent to provide a composition comprising a continuous phase and a discontinuous phase, wherein the continuous phase comprises at least part of the halogenated polymer and at least part of the solvent, and wherein the continuous phase is a solution
Implementation Method 2
separating the continuous phase and the discontinuous phase
Implementation Method 3
evaporating the solvent from the continuous phase to provide a halogenated polymer product
Data Source
Figure 1~2
AI summary
The present invention relates to a process for making a polymer article comprising providing a halogenated polymer product obtained by a process comprising mixing a ground halogenated polymer starting material comprising a halogenated polymer and one or more further components with a solvent to provide a composition comprising a continuous phase and a discontinuous phase, separating the continuous phase and the discontinuous phase, and evaporating the solvent from the continuous phase to provide a halogenated polymer product; and processing the halogenated polymer product to obtain a polymer article.