Integrated r-PET Production Using DMT-Based Chemical Recycling
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Solution Overview
Problem
Conventional recycling technologies face inefficiencies in recycling low-value waste plastics, leading to high operational costs and the production of additional waste streams, while existing chemical recycling processes for polyethylene terephthalate (PET) do not efficiently produce dimethyl terephthalate (DMT)-based PET with recycled content.
Innovation Solution
An integrated chemical recycling facility that combines plastics processing with solvolysis (methanolysis) and PET production, allowing for the production of high inherent viscosity, crystalline PET with up to 100% recycled content by integrating plastic processing, solvolysis, and PET production facilities, optimizing energy consumption and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional chemical recycling processes are used to break down waste plastics into monomers, then plastic waste can be recovered, but high energy consumption and operational costs offset the financial benefits
Solution Approach 1:
The patent combines the solvolysis process with PET production in an integrated facility, where waste PET is converted to monomers and directly repolymerized in the same facility. This integration eliminates the need for separate recycling and production facilities, reducing overall energy consumption and operational costs while maintaining waste recovery effectiveness.
Solution Approach 2:
The PET production facility is designed to accept both virgin monomers and recycled monomers from the solvolysis process, making it universally capable of producing PET from multiple feedstock sources. This multi-functionality allows the facility to optimize between different input sources based on availability and cost, reducing overall operational expenses.
2Productivity
If conventional PET facilities are configured to produce PET based on terephthalic acid (TPA), then production efficiency is maintained, but DMT-based PET with recycled content cannot be efficiently produced
Solution Approach 1:
The patent modifies the PET production process parameters to accommodate DMT as a feedstock instead of only TPA. This involves adjusting reaction conditions, catalyst selection, and process temperature to optimize for dimethyl terephthalate conversion, enabling the facility to efficiently produce DMT-based PET while maintaining overall production efficiency.
Solution Approach 2:
The production facility is designed with universal feedstock acceptance, capable of processing both TPA-based and DMT-based monomers. This versatility allows the facility to switch between different feedstock types depending on availability and economic considerations, maintaining productivity while adapting to different input materials.
3Loss of substance
If low-value waste plastic streams are processed with conventional recycling technologies, then some material recovery is achieved, but additional waste streams are produced that are not economically feasible to recover
Solution Approach 1:
The patent implements a comprehensive recovery system that captures and recycles all waste streams generated during the solvolysis process. Instead of discarding byproducts, the system recovers them and feeds them back into the process or converts them into usable products, eliminating additional waste streams while maintaining high material recovery rates.
Solution Approach 2:
The patent converts the waste streams and byproducts generated during solvolysis into beneficial products. By chemically processing these previously harmful waste streams, the system transforms them into valuable intermediates or end products, turning the harmful effect of waste generation into a benefit of additional material 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
The integrated facility efficiently produces high-quality, DMT-based PET with recycled content, reducing energy consumption and operational costs, and enhancing the properties of PET during processing and end use.
Implementation Method 1
Solvolysis can be used to decompose plastics such as polyethylene terephthalate (PET) into its component monomers (e.g., ethylene glycol and dimethyl terephthalate)
Implementation Method 2
these recycling processes can require high operation costs, specifically in terms of energy consumption, that may offset any financial benefit of utilizing waste plastics as a feedstock
Implementation Method 3
This permits more efficient production and chemical recycling with product formation. Additionally, this results in the production of high inherent viscosity (IV), crystalline PET formed from the recycled content EG (r-EG) and/or recycled content dimethyl terephthalate (r-DMT) formed during solvolysis
Data Source
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AI summary
Processes and systems for producing recycled content polyethylene terephthalate (r-PET) are provided. Integration of chemical recycling facilities with PET production facilities reduces energy consumption and helps minimize adverse environmental impacts, while providing valuable end products having up to 100 percent recycled content. Additionally, processes and systems described herein may provide high IV, crystalline PET based on dimethyl terephthalate, which can exhibit desirable properties during molding and other end use applications.