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Waste artificial marble pyrolysis and hydrolysis.
Jacopo De Tommaso1, Federico Galli2, Tien Dat Nguyen1
1Génie Chimique, Polytechnique Montréal, 2500 ch. de Polytechnique Montréal, Québec, Canada.
Waste Management (New York, N.Y.)
|February 7, 2025
Summary
Recycling artificial marble (PMMA and aluminum hydroxide) is challenging. Pyrolysis and hydrolysis offer a viable solution, recovering 66% MMA and valuable alumina precursors.
Area of Science:
- Materials Science
- Chemical Engineering
- Sustainable Chemistry
Background:
- Artificial marble, a composite of Poly Methyl Methacrylate (PMMA) and aluminum hydroxide (Al(OH)3), is widely used but difficult to recycle due to cross-linking.
- Current recycling methods for artificial marble are either impossible (mechanical) or unprofitable (chemical).
- A need exists for economically viable recycling solutions that preserve the value of both organic and inorganic components.
Purpose of the Study:
- To investigate the pyrolysis and hydrolysis of end-of-life artificial marble for valorization.
- To identify optimal conditions for maximizing the recovery of valuable products from artificial marble waste.
- To assess the potential for retaining the value of the inorganic fraction during recycling.
Main Methods:
- Investigated pyrolysis and hydrolysis of post-consumer artificial marble under varying temperatures, water content, catalysts, and heating styles.
- Analyzed the decomposition pathways of PMMA and the transformation of Al(OH)3 under thermal and hydrolytic conditions.
- Determined optimal heating profiles for maximizing monomer recovery and inorganic fraction conversion.
Main Results:
- A dual-phase process involving controlled heating achieved a 66% yield of methyl methacrylate (MMA) from PMMA.
- The inorganic fraction transformed into a γ-alumina precursor (boehmite), with residual polymer enabling energy-self-sufficient calcination.
- Optimal conditions involved initial water release at 300°C followed by MMA production at 400°C.
Conclusions:
- Pyrolysis and hydrolysis present a sustainable and economically viable recycling method for artificial marble.
- This process effectively recovers valuable MMA and retains the value of the inorganic fraction as alumina precursors.
- The developed method addresses the recycling challenges of this widely used composite material.
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