Hydrogen-rich gas production from disposable COVID-19 mask by steam gasification

Carbon dioxide gasification characteristics of disposable COVID-19 masks using bubbling fluidized bed reactor

The global demand for masks has increased significantly owing to COVID-19 and mutated viruses, resulting in a massive amount of mask waste of approximately 490,000 tons per month. Mask waste recycling is challenging because of the composition of multicomponent polymers and iron, which puts them at risk of viral infection. Conventional treatment methods also cause environmental pollution. Gasification is an effective method for processing multicomponent plastics and obtaining syngas for various applications. This study investigated the carbon dioxide gasification and tar removal characteristics of an activated carbon bed using a 1-kg/h laboratory-scale bubble fluidized bed gasifier. The syngas composition was analyzed as 10.52 vol% of hydrogen, 6.18 vol% of carbon monoxide, 12.05 vol% of methane, and 14.44 vol% of hydrocarbons (C2-C3). The results of carbon dioxide gasification with activated carbon showed a tar-reduction efficiency of 49%, carbon conversion efficiency of 45.16%, and cold gas efficiency of 88.92%. This study provides basic data on mask waste carbon dioxide gasification using greenhouse gases as useful product gases.

Laboratory investigation on added-value application of the COVID-19 disposable mask in hot mix asphalt (HMA)

The outbreak of the COVID-19 pandemic has stimulated the demand for disposable masks to an unprecedented level, which also poses a significant risk to the natural environment from the improper treatment or disposal of waste masks. To lower such an environmental risk and maximize the added value of the waste masks, this paper proposed to recycle the waste mask fiber (MF) in combination with the waste cooking oil (WCO) for hot mix asphalt (HMA) application. A series of MF + WCO modified asphalt binders were first designed and fabricated. Their performance properties were then systematically measured. The physical-rheological test results showed that the incorporation of MF can significantly improve the high-temperature rutting resistance performance of asphalt binder. However, it may also lower the asphalt's low-temperature anti-cracking performance. The addition of WCO was found to compensate for this low-temperature performance loss effectively, and the MF5% + WCO3% was identified as the best combination. The Fourier transform infrared (FTIR) spectroscopy test results revealed that the asphalt modified by the MF + WCO involved only a physical modification. The performance test results indicated that the high-temperature permanent deformation resistance and low-temperature anti-cracking of MF5% + WCO3% modified HMA was greatly enhanced, while its moisture stability was slightly reduced but still met the specification requirement. The environmental benefit assessments proved that recycling the waste masks for asphalt paving can provide an enormous added value to pavement engineering in terms of carbon emission reduction and land resource saving.