Acid Vapor Decomposition of Composite Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current recycling methods for fiber-reinforced organic matrix composite materials are inefficient, as they either fail to recover intact fibers, are expensive, or degrade the fibers' mechanical properties, making them unsuitable for high-value applications and industrial-scale implementation.
Innovation Solution
A process using a vapor phase of acetic acid and hydrogen chloride to degrade the resin matrix at relatively low temperatures, allowing for the separation of intact or quasi-intact fibers and potentially degraded resin monomers/oligomers, with a two-stage reactor system and a perforated plate for efficient fiber recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pyrolysis is used to recover carbon fibers from composites, then the resin is eliminated, but the high temperatures destroy the fiber size and mechanical properties
Solution Approach 1:
The invention changes the temperature parameter from high (pyrolysis above 600°C) to low (100-200°C), and changes the chemical environment from oxidative to acidic vapor phase, enabling resin degradation without fiber damage and preserving tensile strength
Solution Approach 2:
The invention introduces acetic acid and hydrochloric acid vapors as intermediary substances that mediate the degradation of the resin matrix, allowing fiber separation without direct thermal contact that would cause fiber damage
2Productivity
If mechanical grinding is used to process composite parts, then the parts are reduced to smaller pieces, but fiber recovery is not possible and high value-added applications are lost
Solution Approach 1:
The invention replaces the mechanical grinding system with a chemical degradation system using acidic vapor phase, enabling non-mechanical separation that preserves fiber integrity while maintaining processing efficiency
3Reliability
If supercritical fluids are used for resin degradation, then the process can be performed, but high temperature and high pressure conditions are required
Solution Approach 1:
The invention changes the temperature parameter from supercritical (>374°C) to moderate (100-200°C), and changes the pressure from high (2.21 x 10^7 Pa) to atmospheric or slight positive pressure, by using acidic vapor phase instead of supercritical fluids
4Loss of substance
If conventional recycling methods are used, then resin elimination can be achieved, but solid by-products are produced making fiber washing difficult
Solution Approach 1:
The invention changes the chemical state of degradation products from solid residues to soluble/volatile species by using acidic vapor phase degradation, enabling easy fiber washing without difficult solid by-product removal
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 recovers fibers with preserved mechanical properties and avoids solid by-products, facilitating easy washing and potential reuse, while being cost-effective and scalable.
Implementation Method 1
a vapor phase formed of acetic acid and hydrogen chloride is acted on said composite material until the fibers become detached from the degradation products of said resin matrix thus formed
Implementation Method 2
said resin being a resin containing C-N and/or C-O bonds
Implementation Method 3
acetic acid and hydrochloric acid being placed in the bottom of the reactor and heated to provide the required vapor phase
Implementation Method 4
the degradation products in flowable form falling through the perforations of said plate and the separated fibers being recovered on said perforated plate
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention relates to a process for decomposing a composite material consisting of an organic resin matrix reinforced by fibers in order to recover said fibers and where applicable the degradation products of said resin matrix, said resin being a resin containing CN and/or CO bonds, characterized in that a vapor phase formed of acetic acid and hydrogen chloride is acted on said composite material until the fibers detach from the degradation products of said resin matrix thus formed and the latter are separated from said fibers.