Pyrolysis behaviour of shellfish waste via TG-FTIR and Py-GC/MS

Abstract

Shellfish waste (SW), a by-product of seafood processing and consumption, poses ecological concerns from improper management, resulting adverse effects such as water pollution, habitat degradation, and destruction of local ecosystems. Furthermore, the inefficient disposal of SW goes against the principles of circular economy and resource utilization. Therefore, this study is conducted to convert and reuse SW and transform it into value-added products, thereby contributing to sustainable waste management practices. Shellfish waste was characterized for its elemental and proximate contents, followed by performing pyrolysis of SW to study the pyrolysis behaviors and chemical composition of pyrolytic products. Thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) was employed to identify the optimal pyrolysis temperature range (660–780 °C). Additionally, pyrolysis combined with gas chromatography/mass spectrometry (Py-GC/MS) was utilized to analyze gaseous products generated from SW pyrolysis. The analysis revealed that SW possesses a low high calorific value (5.57–8.05 MJ/kg) and high H/C (0.3–1.3) and O/C (3.2–5.2) ratios, rendering it unsuitable for direct use as fuel. Optimal pyrolysis conditions were identified within the temperature range of 660–780 °C through TG-FTIR analysis. Py-GC/MS analysis at 700 °C and a heating rate of 30 °C/min indicated that carboxyl compounds (37.3–87.0%) constituted the dominant components of gaseous products generated during SW pyrolysis. In conclusion, the study underscores the promise of pyrolysis as a viable method for transforming SW into value-added chemicals. The findings of this study contribute to the advancement of sustainable waste management strategies and the utilization of waste materials for valuable purposes in various industries.