Plastic Waste Conversion via Selective Extraction and Hydrothermal Processing
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Solution Overview
Problem
Current methods for converting plastic waste into useful products are inefficient and costly, leading to high levels of plastic accumulation in landfills and oceans, with only a small percentage being recycled due to the lack of cost-effective technologies for processing mixed plastic waste.
Innovation Solution
The development of methods such as Selective Sequential Extraction and Adsorption (SSEA) and Hydrothermal Processing (HTP) that utilize solvent mixtures and subcritical or supercritical water to convert plastic waste into pristine polymers and hydrocarbon mixtures, allowing for the separation and recovery of high-value products from mixed plastic feedstocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical recycling is used to process sorted plastics, then useful products can be produced, but the process is not cost-effective and has limited product options
Solution Approach 1:
The patent changes the chemical parameters of the plastic waste by using depolymerization reactions that break down polymer chains into monomers or oligomers. This chemical transformation enables the production of multiple high-value products including fuels, chemicals, and raw materials for new plastic production, thereby increasing versatility while maintaining cost-effectiveness through a single processing method
Solution Approach 2:
The patent replaces the mechanical recycling process with a chemical depolymerization process. Instead of physically sorting and reprocessing plastics mechanically, the invention uses chemical reactions (such as pyrolysis, hydrolysis, or glycolysis) to break down plastic polymers into useful products, which resolves the limitation of limited product options and low cost-effectiveness
2Use of energy by moving object
If plastic waste is incinerated for energy recovery, then some energy can be obtained, but greenhouse gases and toxic pollutants are emitted
Solution Approach 1:
The patent converts the harmful plastic waste material into beneficial products through depolymerization. Instead of burning plastics and releasing harmful emissions, the chemical processes break down plastic into useful monomers, fuels, and chemicals, transforming the harmful waste stream into valuable resources while avoiding greenhouse gas emissions
3Ease of manufacture
If plastic waste is sent to landfills for disposal, then waste management is simple and low-cost, but plastic degrades slowly and pollutes the environment
Solution Approach 1:
The patent extracts value from plastic waste by depolymerizing it into useful products. Instead of simply disposing of plastic in landfills where it persists for centuries, the invention extracts monomers, fuels, and chemicals through chemical processes, eliminating the waste problem while generating valuable products
4Productivity
If sorted plastics are used as feedstock, then high-value products can be produced, but sorting costs are high
Solution Approach 1:
The patent segments the plastic waste processing at the molecular level through depolymerization, breaking down complex polymer structures into simpler monomer units. This molecular segmentation allows mixed plastic waste to be converted into uniform valuable products without requiring expensive mechanical sorting, as the chemical process handles diverse plastic types uniformly
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
These methods enable the efficient conversion of a significant portion of plastic waste into valuable polymers and hydrocarbon mixtures, reducing the need for petroleum-based products and minimizing CO2 emissions, while providing economic incentives for large-scale implementation.
Implementation Method 1
selecting a solvent mixture (SMi) from a plurality of solvents, wherein Hansen parameters of the selected solvent mixture are within the Hansen's sphere of a target plastic
Implementation Method 2
selectively heating the Mi to a temperature ranging from 5° C. to 180° C. corresponding to a schedule of temperature vs. known type of plastic
Implementation Method 3
heating the reactor to a temperature ranging from 200° C. to 550° C., forming subcritical or supercritical H2O within the reactor
Implementation Method 4
heating the reactor to a temperature ranging from 200° C. to 550° C., forming subcritical or supercritical H2O within the reactor, and waiting a predetermined amount of time, to allow thermal depolymerization of polymers in the feedstock
Implementation Method 5
treating the PPSlOi using one or more adsorbents for the organic additives to thereby remove organic additives forming a pristine polymer solution (PPSi)
Implementation Method 6
the step of separating the_prP from the PPS is by evaporating the S1
Data Source
AI summary
Methods of recovery of pristine polymers and hydrocarbon mixtures from a sorted waste feedstock or mixtures of waste feedstock, which are with or without organic additives are disclosed. The methods include Sequential Selective Extraction and Adsorption (SSEA), Hydrothermal Processing (HTP), and a combination of SSEA and HTP. Exemplarily, SSEA includes selecting a first solvent (S1), inputting the S1 and a sorted feedstock free of organic additives into an extractor, heating, waiting, and separating insolubles forming a pristine polymer solution. Exemplarily, HTP includes inputting a hydrothermal solvent and a sorted feedstock free of organic additives into a reactor, heating to form subcritical or supercritical H2O, waiting, causing thermal depolymerization to produce a slurry, cooling, venting formed gases and separating the hydrocarbon mixture.