Liquid Solvent Treatment for Polymer Volatile Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for treating plastic materials with steam or inert gas at elevated temperatures are inefficient in removing volatile components, leading to persistent emissions, taste, and odor issues, particularly in applications like drinking water pipes and automobile parts, and result in the generation of unwanted fines and streamers during conveying.
Innovation Solution
A process using a liquid solvent at a temperature below its boiling point to contact and treat plastic materials, allowing for efficient removal of volatile components without the need for massive air or inert gas, reducing energy consumption, and minimizing the generation of fines and streamers, with water being a preferred solvent due to its low solubility of monomers and hydrocarbons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If steam or inert gas at elevated temperature is used to treat plastic material, then volatile components are removed to some extent, but removal efficiency is insufficient and emissions, taste and odor are not sufficiently improved
Solution Approach 1:
The patent changes the physical state parameter of the treatment medium from gas (steam or inert gas) to liquid (water). This parameter change enables much more efficient removal of volatile components from plastic pellets. The liquid water phase allows for superior contact and extraction of volatile substances compared to gas phase, thereby significantly reducing emissions, taste, and odor problems.
Solution Approach 2:
The patent employs hydraulic principles by using liquid water instead of pneumatic methods (steam or inert gas). The liquid phase provides better hydraulic contact with the plastic pellets, enabling more effective removal of volatile components. This hydraulic approach fundamentally improves the treatment efficiency compared to traditional pneumatic methods.
2Quantity of substance
If hot polymer pellets are pneumatically conveyed for removing volatile components, then treatment can be performed, but generation of unwanted fines and streamers occurs due to friction
Solution Approach 1:
The patent replaces pneumatic conveying with hydraulic conveying using liquid water. Instead of using gas flow to transport and treat the pellets, the invention uses liquid water as both the treatment medium and conveying medium. This eliminates the high-velocity gas-particle interactions that cause friction, preventing the generation of fines and streamers while maintaining effective volatile component removal.
3Productivity
If steam is used for removing volatile components, then treatment efficiency is improved, but handling becomes more difficult and additional condensation equipment is required
Solution Approach 1:
The patent uses liquid water, which is inexpensive and readily available, replacing expensive and complex steam generation and handling systems. Water can be easily pumped, distributed, and disposed of or recycled without requiring complex condensation equipment. This principle of using simple, inexpensive media (liquid water) instead of complex systems (steam generation and condensation infrastructure) significantly improves ease of operation while maintaining or enhancing treatment efficiency.
4Quantity of substance
If massive amounts of air or inert gas are used for removing volatile components, then removal efficiency is improved, but energy consumption increases
Solution Approach 1:
The patent replaces pneumatic methods requiring massive gas flows with hydraulic methods using liquid water. The liquid phase provides much higher density and better contact efficiency, achieving superior volatile component removal with minimal water consumption. This eliminates the need for energy-intensive gas generation, heating, and circulation systems, dramatically reducing energy consumption while improving removal efficiency.
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 process effectively removes a high percentage of volatile components, improving energy efficiency and reducing emissions, while avoiding the need for additional drying steps and costly safety precautions, achieving significant reductions in volatile content within a short treatment time.
Implementation Method 1
contacting plastic material with a solvent in liquid form... the use of a liquid instead of steam according to the invention not only removes volatile components more efficiently from the plastic material
Implementation Method 2
The volatile components comprise monomers, hydrocarbons and hydrocarbon derivatives... The process particularly removes volatile components containing 2 to 20 carbon atoms
Implementation Method 3
In the inventive process and plant vaporized liquid may be used to heat the liquid, whereby the amount of vaporized liquid which has to be recondensed is much less compared with prior art processes
Implementation Method 4
Energy savings additionally originate from the facilitated heat transfer from liquid to solid plastic material compared to the heat transfer from gas to solid plastic material
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention is directed to a process for the treatment of plastic material comprising a) providing a liquid; b) contacting the plastic material with the liquid; c) keeping the plastic material in the liquid at Tb-25 °C to Tb of the liquid, wherein Tb is the boiling point of the liquid at the applied pressure; and d) removing the plastic material from the liquid. Furthermore, the invention is directed to the use of a liquid for the treatment of plastic material and to a plant for treating plastic material with a liquid.