Ozone Odour Removal for Recycled Plastic Regranulate Purity
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Solution Overview
Problem
Conventional methods for recycling post-consumer plastic waste are energy-intensive and inefficient in removing odors and microbial contaminants, leading to impurities that prevent the production of high-purity, food-grade regranulate.
Innovation Solution
A process and device utilizing a pre-treatment unit, melting extruder, degassing extruder, granulating device, and odour removal unit with ozone-enriched gas to effectively remove odors from shredded and washed plastic flakes, controlled by an inline measurement system to optimize ozone use and minimize environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional degassing systems are used to decontaminate post-consumer waste, then the decontamination process can be completed, but the process becomes particularly energy- and time-intensive
Solution Approach 1:
The patent changes the chemical parameter of the gas stream by introducing ozone (O3) instead of conventional hot air or vacuum. This chemical parameter change enables more effective decontamination and odour removal while reducing energy consumption, as ozone actively oxidizes contaminants rather than requiring prolonged thermal exposure or vacuum processing.
Solution Approach 2:
The patent employs ozone as a strong oxidant to accelerate the decomposition of organic contaminants and removal of odours from plastic waste. This oxidation process breaks down contaminants more efficiently than conventional thermal drying, significantly reducing both energy consumption and processing time while maintaining effective decontamination.
2Reliability
If conventional degassing systems are used to decontaminate post-consumer waste, then the decontamination process can be completed, but the process becomes particularly time-intensive
Solution Approach 1:
The patent changes the chemical parameter of the gas stream by introducing ozone (O3) instead of conventional hot air or vacuum. This chemical parameter change enables more effective decontamination and odour removal while reducing energy consumption, as ozone actively oxidizes contaminants rather than requiring prolonged thermal exposure or vacuum processing.
Solution Approach 2:
The patent employs ozone as a strong oxidant to accelerate the decomposition of organic contaminants and removal of odours from plastic waste. This oxidation process breaks down contaminants more efficiently than conventional thermal drying, significantly reducing both energy consumption and processing time while maintaining effective decontamination.
3Manufacturing precision
If optical pre-sorting is performed before shredding to achieve certain colour purity, then the sorting process can be completed, but the overall process complexity increases
Solution Approach 1:
The patent performs optical pre-sorting of plastic waste by colour and type before the shredding process. This preliminary action ensures that homogeneous materials are processed together, preventing contamination during subsequent processing steps and eliminating the need for complex post-processing sorting operations, thereby achieving high colour purity with manageable process complexity.
4Object-generated harmful factors
If flakes are extruded into regranulates and aerated for extended periods to reduce odour, then the odour reduction can be achieved, but the processing time increases significantly
Solution Approach 1:
The patent employs ozone as a strong oxidant to accelerate the decomposition of organic contaminants and removal of odours from plastic waste. This oxidation process breaks down contaminants more efficiently than conventional thermal drying, significantly reducing both energy consumption and processing time while maintaining effective decontamination.
Solution Approach 2:
The patent changes the chemical parameter of the gas stream by introducing ozone (O3) instead of conventional hot air or vacuum. This chemical parameter change enables more effective decontamination and odour removal while reducing energy consumption, as ozone actively oxidizes contaminants rather than requiring prolonged thermal exposure or vacuum processing.
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
Achieves efficient odor removal from post-consumer plastic waste, producing high-purity regranulate suitable for food packaging by ensuring complete odorant oxidation while minimizing ozone emissions.
Implementation Method 1
a pre-treatment unit (2) for drying and homogenizing the flakes from shredded and washed post-consumer plastic waste
Implementation Method 2
a melting extruder (3) located downstream of the pre-treatment unit (2) for melting the plastic waste dried and homogenized in the pre-treatment unit (2)
Implementation Method 3
a degassing extruder (5) arranged downstream of the melting extruder (3) and having a connection to a vacuum source for degassing the plastic melt
Implementation Method 4
a granulating device (6) arranged downstream of the degassing extruder (5) for granulating the plastic melt
Implementation Method 5
an odour removal unit (8) disposed downstream of the granulating device (6) for subjecting the granules to odour removal, having a process gas inlet (10) and a gas outlet (11) for discharging an exhaust gas stream, the process gas inlet (10) of the odour removal unit (8) being connected to an ozone source (12) or an ozone generating device (13), whereby process gas enriched with ozone can be supplied to the odour removal unit (8)
Data Source
AI summary
The device for recycling flakes from shredded and washed post-consumer plastic waste comprises—seen in the processing direction of the plastic waste—a pre-treatment unit (2) for drying and homogenising the flakes from shredded and washed post-consumer plastic waste, a melting extruder (3) for melting the plastic waste dried and homogenized in the pre-treatment unit (2), a degassing extruder (5) having a connection (5a) to a vacuum source for degassing the plastic melt, a granulating device (6) for granulating the plastic melt, and an odour removal unit (8) to subject the granules an odour removal.The odour removal unit (8) has a process gas feed (10) and a gas discharge (11) for discharging an exhaust gas stream, wherein the process gas feed (10) of the odour removal unit (8) is connected to an ozone source (12) or an ozone generating device (13), whereby the odour removal unit (8) may be supplied with process gas enriched with ozone.