Circumventing Unintended Impacts of Waste N95 Facemask Generated during the COVID-19 Pandemic: A Conceptual Design Approach

Oseweuba Valentine Okoro,Hongxia Zhang,Adjoa Nkrumah Banson

doi:10.3390/chemengineering4030054

Abstract

The global crisis arising from the current COVID-19 pandemic has resulted in a surge in the magnitude of global waste from used Personal Protective Equipment with special emphasis on waste N95 facemask. Creative approaches are therefore required to resolve the surging facemask waste disposal issue in an economical and environmentally friendly manner. In an attempt to resolve the evolving global waste challenge, the present study has assessed the economic and environmental performances of converting N95 facemasks to steam and electricity via a combined heat and power plant, to ethanol via a syngas fermentation process, and to an energy-dense gasoline-like oil product via a hydrothermal liquefaction process. These processes were assessed using “conceptual” process models developed using ASPEN plus as the process simulation tool. Economic and environment assessments were undertaken using net present values (NPVs) and the rate of potential environmental impacts (PEIs) respectively, as sufficient performance measures. Therefore, the present study was able to establish that the conversion of waste N95 facemask to syngas prior to a fermentation process for ethanol production constituted the least economical and least environmental friendly process with a negative NPV and the highest rate of PEI (1.59 PEI/h) value calculated. The NPV values calculated for N95 facemask waste conversion to steam and electricity and energy-dense oil processes were US$ 36.6 × 106 and US$ 53 × 106 respectively, suggesting the preference for the production of a valuable energy-dense oil product. Furthermore, it was observed that when the environmental performance of both processes was considered, rates of PEIs of 1.20 and 0.28 PEI/h were estimated for the energy-dense oil production process and the steam and electricity generation process, respectively. Therefore, the study was able to establish that the utilisation of waste N95 facemask for steam and electricity generation and for generating an energy-dense oil product are both promising approaches that could aid in the resolution of the waste issue if both environmental and economic performances constitute crucial considerations.

Highlights

In December 2019, cases of “pneumonia” of unknown origin appeared in the Wuhan city in the Wubei province of China, which resulted in a number of hospital admissions [1,2]
This result is slightly larger than the yield of syngas of 2.4 kg per kg of wood biomass [53] with the difference explained by the difference in feedstock as highlighted by the comparatively higher carbon and hydrogen content of the waste N95 facemask
The results show that for the waste N95 facemask composed of cellulose and propylene, in mass ratios of 1:3, the resulting energy-dense oil product was characterised by negligible 5-(hydroxymethyl)furfural formation-based compositional estimates using the Gibbs free energy minimisation reaction approach

Summary

Introduction

In December 2019, cases of “pneumonia” of unknown origin appeared in the Wuhan city in the Wubei province of China, which resulted in a number of hospital admissions [1,2]. The COVID-19 virus targets the human respiratory system, and similar to other respiratory viruses, it is highly contagious through infected aerosols from the mouth and nose released during coughing, sneezing, or even talking [1,2]. This is because the virus is transmitted through respiratory droplets that are at least 5 to 10 μm in diameter [2]. The COVID-19 virus itself is reported to be approximately 0.125 microns in size and is capable of “travelling” up to 1.8 m from the source to eventually settle on surfaces [3] Within this radius, the virus could be inhaled by other persons, leading to serious health complications in some cases [2]. Of the different types of these masks, surgical respirator masks were demonstrated to serve as effective protective barriers that reduced the wearer’s exposure to airborne biological pathogens such as COVID-19 virus [5]

Methods

Results

Conclusion