Polyolefin Waste Sorting Plant for 2D Fraction Purity
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Solution Overview
Problem
Current methods for sorting polymer-based waste, particularly polyolefins, are inefficient in separating two-dimensional fractions suitable for chemical recycling, leading to high costs and limited application of chemical recycling due to contamination with unwanted materials.
Innovation Solution
A plant and method utilizing a series of mechanical sorting processes including magnetic and optical separators, shredding, and aeraulic separation to effectively separate two-dimensional polyolefin fractions from three-dimensional and non-polyolefin materials, ensuring high purity for chemical recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical recycling methods are used for sorting polymer waste, then processing costs are reduced, but the quality and purity of sorted fractions deteriorate, limiting applicability for chemical recycling
Solution Approach 1:
The sorting process is divided into multiple sequential stages: preliminary mechanical sorting, optical sorting, and aeraulic sorting. Each stage targets specific contaminants and progressively purifies the polyolefin fraction, allowing mechanical methods to handle bulk separation while more precise methods refine the final product.
Solution Approach 2:
The invention changes the separation parameter from purely mechanical properties (size, shape) to include aerodynamic properties (bulk density, air resistance). The aeraulic separator uses controlled air flows to separate materials based on their aerodynamic characteristics, enabling differentiation between 2D and 3D polyolefin structures that mechanical sorters cannot distinguish.
2Reliability
If chemical recycling is applied to contaminated waste fractions, then material recovery value increases, but process efficiency decreases due to contamination with unwanted materials
Solution Approach 1:
The patent implements comprehensive preliminary sorting actions before chemical recycling. Mechanical separators remove large contaminants, optical separators identify and remove non-polyolefin materials, and aeraulic separators eliminate remaining unwanted fractions. This preliminary purification ensures that only high-purity polyolefin fractions proceed to chemical recycling, maintaining process efficiency.
Solution Approach 2:
The invention replaces traditional mechanical sorting systems with an aeraulic separation system that uses controlled air flows instead of mechanical contact. This substitution enables separation based on aerodynamic properties rather than mechanical properties, achieving higher purity levels without the contact and contamination risks of mechanical systems.
3Manufacturing precision
If aeraulic separation is used to separate two-dimensional from three-dimensional polyolefin fractions, then purity for chemical recycling is improved, but device complexity increases
Solution Approach 1:
The sorting plant is segmented into modular units: feeding station, mechanical separation section, optical separation section, and aeraulic separation section. Each module performs a specific function and can be independently adjusted or maintained. The aeraulic separator itself is divided into multiple chambers with different air flow characteristics, allowing systematic separation without overwhelming complexity.
Solution Approach 2:
The aeraulic separator is designed to handle multiple types of polyolefin materials (polyethylene, polypropylene) and separate them based on their aerodynamic properties. The same device can process different input mixtures and produce consistently pure outputs, reducing the need for multiple specialized devices and thereby managing complexity.
4Manufacturing precision
If multiple sorting stages are implemented to remove unwanted materials, then contamination is reduced, but processing time and operational complexity increase
Solution Approach 1:
The sorting plant operates as a continuous flow system where material moves sequentially through mechanical separation, optical separation, and aeraulic separation without interruption. Each stage processes material at the same rate, eliminating batch processing delays and idle time. The continuous operation maintains high purification levels while minimizing total processing time.
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 solution enables efficient and reliable production of a two-dimensional polyolefin mixture suitable for chemical recycling, reducing contamination and increasing the applicability of chemical recycling processes.
Implementation Method 1
an aeraulic separator configured for separating the three-dimensional polyolefin fraction, comprising the polyolefin fragments with bulk density higher than a predefined threshold value, from the two-dimensional polyolefin fraction, comprising the polyolefin fragments with bulk density lower than the predefined threshold value
Implementation Method 2
at least one optical separator configured for removing from the flow of material to be treated the non-polyolefin polymers, the cellulosic components and the textile components
Implementation Method 3
a first station configured for removing the metal fragments from the flow of material to be treated
Data Source
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AI summary
The invention concerns a plant 20 for the production of a mixture of waste based on polyolefins and XPS suitable for feeding into a pyrolytic reactor. The plant comprises: a feeding station 22 that releases a flow of material to be treated 100; a first station 24 for removing the metal fragments 102; at least one optical separator 28 for removing the non-polyolefin polymers 106 and the textile and cellulosic fractions; a screen 30 for removing the foreign bodies 108 with dimensions smaller than a predefined minimum; a shredder 32 for reducing the particle size of the material to be treated; a second station 34 for removing the metal fragments; and an aeraulic separator 36 for separating the three-dimensional polyolefin fraction 110 from the two-dimensional polyolefin fraction 112. The invention also concerns a method for the production of a mixture of waste based on polyolefin and XPS, suitable for chemical recycling.