ABSTRACT
The COVID-19 pandemic has created a new type of waste (surgical mask waste “WMs”) that presents a major challenge now and in the future, given the strong possibilities of similar epidemics to reoccur. In order to find an effective industrial solution to the millions of WMs produced daily, this research aims to develop a new eco-friendly strategy to convert WMs into H2-CH4-rich syngas, carbon nanoparticles (CNPs), and benzene-rich tar using an updraft gasifier system. The experiments started with the preparation of WM granules using shredding followed by granulation processes. Subsequently, the granules were processed in a lab-scale reactor with a capacity of 0.9–1 kg/h and consisted of a continuous WM feed system, a gasifier, a sampling system for syngas and tar, a ceramic filtration unit for separating the CNPs against the synthesis gas, and a burner. The gasification experiments were performed in ambient air with different air−fuel equivalence ratios (ER: 0.21, 0.25, and 0.29) and temperatures (700°C, 800°C, and 900°C) to determine the optimal conditions that yield the maximum amount of H2-CH4-rich syngas and CNPs with less impurities. The chemical composition and morphology of the obtained gasification products (syngas, tar, and CNPs) were observed using GC-FID, FTIR, and SEM. The results showed that the maximum production of syngas (4.29 ± 0.16 kg/h with HHV of 3804 kJ/kg) and CNPs (0.14 ± 0.011 kg/h) accompanied by a moderate tar rate (0.123 ± 0.009 kg/h with HHV of 41,139.88 kJ/kg) could be obtained at 900°C and ER = 0.29, while the highest H2 (16.93 ± 1.7 vol.%) and CH4 (10.44 ± 0.85 vol.%) contents in syngas product were synthesized at 900°C and ER = 0.19. Benzene and toluene were the major GC-FID compounds in the formulated tar product with abundance up to 25.6% and 11%, respectively. Meanwhile, gasification conditions of 900°C and ER = 0.24 allowed the best morphology to be formulated for spherical-shaped CNPs with a diameter of less than 200 nm.
Acknowledgements
This project has received funding from European Regional Development Fund (project No 13.1.1-LMT-K-718-05-0017) under grant agreement with the Research Council of Lithuania (LMTLT). Funded as European Union’s measure in response to Cov-19 pandemic.
Disclosure statement
No potential conflict of interest was reported by the authors.