Pyrolysis recovery and product distribution of shrimp shell waste: Insights from thermogravimetric-Fourier transform infrared spectroscopy and pyrolysis–gas chromatography/mass spectrometry characterization

Abstract

Shrimp consumption is increasing owing to its rich nutrition and delicious taste. As a result, the generation of shrimp shell waste is also increasing, while the current disposal method such as landfilling causes pollution and produces harmful leachate to living organisms and the environment. Therefore, a proper management strategy is needed to dispose of shrimp shell waste to mitigate the adverse effects caused to the environment. This study presents an in-depth approach to reveal the properties of shrimp shell waste and explore its potential for use in various applications. The shrimp shell waste was subjected to pyrolysis–gas chromatography/mass spectrometry and thermogravimetric-Fourier transform infrared spectroscopy pyrolysis to evaluate the gas composition from pyrolysis. Thermogravimetric-Fourier transform infrared spectroscopy analysis reveals that when the optimal temperature for pyrolysis is 400 °C–600 °C, the predominant functional group of gases produced are –CH, –OH, and –NH. On the other hand, the results of pyrolysis–gas chromatography/mass spectrometry indicate that hydrocarbon (51.86%) is the main product of shrimp shell waste pyrolysis at 900 °C, which can be used in paints, paint thinners, rubber, printing inks, adhesives (glue). Although it has a calorific value of 15.113 MJ/kg, it cannot be directly burned because of its high nitrogen concentration (10.85 wt.%) which may generate harmful pollutants such as nitrogen oxides. Overall, pyrolysis is recommended as a viable method for converting shrimp shell waste into versatile products.