Artificial Turf Recycling via Pyrolysis and Density Separation
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Solution Overview
Problem
The limited options for recycling artificial turf are hindered by its composite nature, including thermoplastic and thermoset components, and contamination with inorganic fillers, making mechanical recycling difficult and inefficient.
Innovation Solution
A method involving thermal treatment of artificial turf to produce hydrocarbons, where the turf feed is subjected to pyrolysis or cracking, followed by separation and hydrotreatment to manage contaminants and segregate inorganic materials into char, producing suitable feed for steam crackers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical recycling is used for artificial turf, then the process is simple and low-cost, but the recycling efficiency is low and the output value is low due to the composite nature of the turf materials
Solution Approach 1:
The patent applies thermal treatment parameters (temperature, heating rate, atmosphere control) to transform the physical and chemical properties of the turf materials. The thermoplastic components are heated above their melting points to enable flow and separation, while the thermoset components undergo thermal decomposition to release bound materials. This parameter change approach converts the difficult-to-recycle composite into separable streams that can be processed independently.
Solution Approach 2:
The patent replaces mechanical recycling methods with thermal treatment processes. Instead of using mechanical force to physically separate and reprocess the composite materials, the invention uses controlled thermal energy to induce phase changes and chemical transformations that facilitate separation. This substitution allows for more effective handling of the thermoplastic/thermoset composite structure.
2Ease of operation
If mechanical recycling is used for artificial turf, then the process is straightforward, but the output value is low and the quality of recycled materials is poor
Solution Approach 1:
The patent segments the composite turf material into distinct components through thermal treatment. The thermoplastic carpet portion, thermoset backing material, and infill materials are separated into different streams based on their thermal behavior. This segmentation allows each component to be processed and recovered independently, maintaining high purity and quality of the recycled materials.
Solution Approach 2:
By controlling thermal parameters (temperature profiles, residence time, atmosphere composition), the patent achieves selective transformation of different turf components. The thermoplastic materials melt and can be filtered to remove contaminants, while thermoset materials decompose to release bound polymers. These parameter changes enable production of high-quality recycled materials suitable for various applications.
3Reliability
If pre-washing is performed to remove inorganic fillers before recycling, then the contamination is reduced, but the process becomes more complex and costly
Solution Approach 1:
The patent replaces mechanical pre-washing operations with thermal treatment. Instead of using water and mechanical agitation to remove inorganic fillers, the invention uses controlled heating to melt thermoplastic components and decompose thermoset components, causing the inorganic fillers to separate naturally during the thermal process. This eliminates the need for separate washing equipment and water management systems.
Solution Approach 2:
The patent converts the presence of inorganic fillers and contaminants into a benefit. During thermal treatment, the inorganic fillers act as heat transfer media and eventually separate as inert residues that can be easily removed. The contaminants that would normally require complex removal processes are instead utilized as part of the thermal treatment mechanism, simplifying the overall process.
4Ease of manufacture
If thermoset rubbers are mechanically recycled, then the process is simple, but the recycling is difficult especially when contaminated with inorganic filler material
Solution Approach 1:
The patent applies thermal parameters to transform the crosslinked thermoset rubber structure. By heating above the decomposition temperature of the thermoset bonds, the patent breaks the crosslinked network and releases the bound polymer chains. This parameter change converts the otherwise irreversibly cured thermoset into processable material that can be separated from inorganic fillers and reused.
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 enables the recycling of artificial turf into valuable hydrocarbons while managing inorganic fillers, reducing the need for costly pre-washing and enhancing the quality of the liquid stream for downstream processing.
Implementation Method 1
subjecting the turf feed to thermal treatment to produce hydrocarbons; wherein the turf feed is subjected to pyrolysis or cracking
Implementation Method 2
subjecting the turf feed to thermal treatment to produce hydrocarbons; wherein the turf feed is subjected to pyrolysis or cracking
Implementation Method 3
removing heavies and entrained solids from the effluent via a separator, wherein an average density of the heavies is greater than an average density of the effluent that enters the separator
Implementation Method 4
hydrotreating the liquid to give a cracker feed for a steam cracker, wherein olefin content of the cracker feed as measured by bromine number is less than 50% of the olefin content of the liquid upstream of the hydrotreating
Data Source
AI summary
Systems and methods are provided for recycling of artificial turf, including, in one embodiment, a method comprising: providing a turf feed including a sized carpet composition; subjecting the turf feed to thermal treatment to produce a liquid effluent including hydrocarbons; and removing entrained solids and heavies from the liquid effluent via a separator, wherein the heavies have an average density greater than the average density of the liquid effluent that enters the separator.