We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Synergistic Effects of Sulfuric Acid and Citric Acid in the Hydrolysis of Polyethylene Terephthalate Plastics
Summary
Adding citric acid to sulfuric acid-catalyzed PET hydrolysis produced more consistent terephthalic acid yields with lower variability compared to sulfuric acid alone, though overall PET conversion was higher with the single-acid approach. Reliable chemical recycling of PET back to its monomer terephthalic acid is essential for creating a closed-loop plastic economy that reduces the PET fragmentation responsible for widespread microplastic contamination.
This study investigated the hydrolysis of polyethylene terephthalate (PET) using sulfuric acid as the catalyst, with citric acid added as a potential modifier to improve terephthalic acid (TPA) yield and PET conversion due to its chelating and buffering properties. The research evaluated whether adding 10 mL of citric acid at varying concentrations (1 M, 3 M, and 5 M) could enhance hydrolysis efficacy compared to sulfuric acid alone, addressing inefficient PET hydrolysis and supporting plastic waste mitigation. Each setup used 5 g of PET in 100 mL of solution, including one control group with 80% sulfuric acid and three treatment groups with added citric acid. Hydrolysis was conducted at 100 °C for 30 minutes with constant stirring, followed by cooling, dilution, filtration, drying, and gravimetric analysis to determine TPA yield and PET conversion. Statistical analysis showed no significant difference in TPA yield between the sulfuric acid–only and citric acid–modified groups. However, significant differences were found in PET conversion, with post hoc results indicating superior conversion in the sulfuric acid–only group. Despite this, citric acid–treated samples produced more consistent TPA yields with lower variability and achieved near-complete conversion at higher concentrations. The sulfuric acid–only group showed highly variable yields, possibly due to increased viscosity and drying difficulty despite similar drying conditions, which may have affected statistical sensitivity. Overall, citric acid shows potential as a hydrolysis modifier, though further studies with improved drying protocols and larger sample sizes are recommended.