Steam Distillation for Odour Elimination in Recycled Plastics
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Solution Overview
Problem
Conventional washing methods are ineffective in eliminating volatile organic compounds (VOCs) that cause foul odors in recycled plastics, limiting their reuse as raw material for exterior products.
Innovation Solution
The method employs steam distillation to remove VOCs from recycled plastics, utilizing a deodorizing module with a distillation column, droplet separator, and isothermal tank to separate and recover VOCs, thereby eliminating odors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional washing methods are used to clean plastic waste, then the washing process is simple and cost-effective, but volatile organic compounds (VOCs) causing foul odors cannot be eliminated
Solution Approach 1:
The patent applies parameter changes by modifying the temperature and phase parameters of the washing system. Steam at elevated temperatures (above 100°C at atmospheric pressure, or higher at elevated pressure) is introduced to extract VOCs from the plastic matrix. This thermal parameter change enables the removal of odor-causing compounds that conventional cold or warm water washing cannot eliminate, while maintaining a relatively simple system configuration.
Solution Approach 2:
The patent utilizes phase transitions of water between liquid and vapor states. Water is heated to generate steam, which penetrates the plastic material and carries volatile organic compounds away from the matrix. The steam condenses back to liquid water in the extraction system, separating the VOCs from the water phase. This phase transition mechanism enables effective VOC removal without requiring complex chemical treatment systems.
2Object-generated harmful factors
If steam distillation is used to remove VOCs from recycled plastics, then VOCs are effectively eliminated, but energy consumption increases
Solution Approach 1:
The patent implements feedback by condensing the steam after it has extracted VOCs from the plastic material. The condensed water is then reused as the washing medium in subsequent batches of plastic waste treatment. This feedback loop recovers the thermal energy that would otherwise be lost, significantly reducing the energy required for continuous steam generation while maintaining effective VOC removal.
Solution Approach 2:
The patent applies discarding and recovering by capturing and condensing the steam-vapor mixture after VOC extraction. Instead of discarding the steam to atmosphere, the system condenses it back to liquid water, separates the extracted VOCs, and recycles the condensed water for reuse. This recovery process eliminates waste of both water and thermal energy, reducing overall energy consumption of the process.
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 process effectively removes VOCs from recycled plastics, improving their quality and enabling their reuse as raw material for exterior products, while also recovering valuable organic compounds that can be marketed or reused as fuel.
Implementation Method 1
The present invention relates to a method for the elimination of odours in recycled plastic materials based on the removal of volatile organic compounds by means of steam distillation
Implementation Method 2
removal of volatile organic compounds by means of steam distillation
Implementation Method 3
there is a droplet separator, downstream of the distillation column, for separating the organic phase from the water steam
Data Source
Figure 1
AI summary
The invention relates to a method and system for the elimination of odours in recycled plastic materials, which comprises the steps of: separating and conditioning the plastic; shredding the plastic by means of a bladed shredded, which reduces the plastic into powder-sized particles; chemically washing with a surfactant, which is carried out in a stirring tank; rinsing the plastic material to eliminate dirt and the chemicals used, which is carried out in a rinsing reactor; mechanically drying the clean material in a dryer; and deodorising the plastic, wherein volatile organic compounds (VOCs) are removed from the clean, dry material by means of steam distillation, deodorisation being performed in a steam distillation column, the VOC-free plastic exiting through the bottom part of the column.