Mechanochemical Dehalogenation of Plastic Waste
Solution Overview
Problem
The recycling of plastic waste, particularly mixed plastics and plastic laminates, is hindered by their high organohalogen content and contamination with persistent organic pollutants (POPs), which pose environmental and health risks and are difficult to remove using conventional methods.
Innovation Solution
A mechanochemical process involving comminution, addition of a dehalogenating agent in excess, and further grinding to produce valuable products free from persistent organic pollutants and organohalogen compounds, followed by separation and addition of various additives to enhance properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional recycling methods are used for plastic waste containing organohalogen compounds and POPs, then the recycling process can proceed, but the harmful substances are not effectively removed and contaminate the recycled products
Solution Approach 1:
The patent extracts and removes harmful substances (POPs and organohalogen compounds) from plastic waste through a multi-stage process involving sorbent materials that selectively bind these contaminants, followed by separation and removal steps that isolate the purified plastic material from the contaminated stream
Solution Approach 2:
The patent introduces intermediary substances including sorbent materials (such as activated carbon, clays, or specialized polymers) that act as mediators to capture and bind POPs and organohalogen compounds, facilitating their removal from the plastic waste without directly treating the plastic itself
2Reliability
If plastic waste is thoroughly cleaned and sorted to remove POPs and organohalogen compounds, then product quality improves, but the process complexity and cost increase significantly
Solution Approach 1:
The patent combines multiple treatment functions into an integrated process flow where sorting, contamination capture, and purification steps are merged into a sequential operation that achieves high product purity without requiring separate complex systems for each function
Solution Approach 2:
The patent alters process parameters such as the chemical composition and physical properties of sorbent materials to optimize their affinity for specific contaminants, enabling effective removal of POPs and organohalogen compounds under controlled conditions that simplify the overall process
3Manufacturing precision
If advanced treatment methods are applied to remove organohalogen compounds and POPs, then product purity increases, but energy consumption and processing time increase
Solution Approach 1:
The patent replaces energy-intensive mechanical or thermal treatment methods with chemically-driven processes using sorbent materials that passively bind contaminants through adsorption and complexation, significantly reducing the energy input required for purification
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
Produces valuable products with novel and improved properties, capable of broad application, while effectively eliminating organohalogen compounds and POPs, even from non-sorted plastic waste and laminates.
Implementation Method 1
addition of a dehalogenating agent in excess, and further grinding to produce valuable products free from persistent organic pollutants and organohalogen compounds
Implementation Method 2
the waste is comminuted to achieve the narrowest possible particle size distribution, (ii) the comminuted waste is fed into a mill containing grinding balls and further comminuted by grinding
Implementation Method 3
addition of various additives to enhance properties
Data Source
AI summary
A mechanochemical process for producing valuable products free of persistent organic pollutants and other organohalogen compounds from waste of sorted and mixed plastics and plastic laminates contaminated with persistent organic pollutants and/or other organohalogen compounds, wherein (i) the waste is crushed to achieve the narrowest possible particle size distribution, (ii) the crushed waste is placed in a mill containing grinding balls and further crushed by grinding, (iii) at least one dehalogenating agent is added in a molar excess relative to the amounts of persistent organic pollutants and/or other organohalogen compounds present, (iv) the mixture of ground crushed waste and dehalogenating agent is further ground and the grinding is stopped after a preselected time.(v) separates the resulting valuable products free of persistent organic pollutants and other organohalogen compounds from the milled balls and separates the resulting halogen-containing, water-soluble products by washing with aqueous solvents and/or does not wash out the resulting halogen-containing, water-insoluble products, but leaves them as fillers in the valuable products and (vi) checks the washed valuable products after drying and the unwashed valuable products to see if they still contain persistent organic pollutants and/or other organohalogen compounds, wherein (vii) at least one additive is added before and/or after process step (iv); valuable products produced using the mechanochemical process and their use.