ABSTRACT
During the COVID-19 pandemic, more than 24 billion pieces of surgical mask waste (WM) were generated in the EU region, with an acute shortage of their management and recycling. Pyrolysis and gasification are among the most promising treatments that were proposed to dispose of WMs and convert them into pyrolysis oil and hydrogen-rich syngas. This work aimed to investigate the techno-economic analysis (TEA) of both treatments in order to assess the feasibility of scaling up. The TEA was carried out using a discounted cash flow model and its data were collected from practical experiments conducted using a fluidised bed pyrolysis reactor and bubbling fluidised bed gasifier system with a capacity of 0.2 kg/h and 1 kg/h, respectively, then upscaling to one tonne/h. The technological evaluation was made based on the optimal conditions that could produce the maximum amount of pyrolysis oil (42.3%) and hydrogen-rich syngas (89.7%). These treatments were also compared to the incineration of WMs as a commercial solution. The discounted payback, simple payback, net present value (NPV), production cost, and internal rate of return (IRR) were the main indicators used in the economic feasibility analysis. Sensitivity analysis was performed using SimLab software with the help of Monte Carlo simulations. The results showed that the production cost of the main variables was estimated at 45.4 EUR/t (gate fee), 71.7 EUR/MWh (electricity), 30.5 EUR/MWh (heat), 356 EUR/t (oil), 221 EUR/t (gaseous), 237 EUR/t (char), and 257 EUR/t (syngas). Meanwhile, the IRR results showed that gasification (12.51%) and incineration (7.56%) have better economic performance, while pyrolysis can produce less revenue (1.73%). Based on the TEA results, it is highly recommended to use the gasification process to treat WMs, yielding higher revenue. [ FROM AUTHOR] Copyright of Energies (19961073) is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
ABSTRACT
This research aims to develop a new thermochemical strategy to extract butane from the billions of wasted Covid-19 masks that are generated every month. The experiments were conducted with 3-ply face masks (3PFM) over ZSM-5 zeolite with different ratios of ZSM-5 to 3PFM (w/w: 6, 12, 25, and 50 wt.%) using thermogravimetry (TGA) at different heating conditions. Also, the effect of ZSM-5 concentration and heating rates was examined using TG-FTIR and GC-MS measurements. Besides, the kinetics behaviour of the developed strategy was modelled using linear and nonlinear isoconversional modelling techniques, thus calculating the activation energy (Ea) for each conversion region. Finally, all required parameters to fit TGA and differential scanning calorimetry (DTG) experimental curves were estimated using the distributed activation energy (DAEM) and the independent parallel reactions (IPR) techniques, respectively. The results showed that the decomposed samples are very rich in aromatic and aliphatic (-C-H) compounds. Meanwhile, and based on GC-MS results, butanol compound was the basic component in the generated compounds with abundance of 31% at 25 wt.% of ZSM-5 at lowest heating rate (5 ˚C/min), whereas the average Ea at 25% of ZSM-5 (sample enriched with butanol) was estimated in the ranges 158-187 kJ mol−1 (linear methods with R2 > 0.96) and 167-169 kJ/mol (nonlinear methods with R2 > 0.98). Finally, DAEM and IPR succeeded to simulate TGA and DTG curves of ZSM-5/3PFM samples with very small deviation. Based on that, the catalytic pyrolysis strategy over ZSM-5 zeolite can be used effectively to dispose of Covid-19 masks and to convert them into butanol compound that can be used as a liquid fuel and lubricant.
ABSTRACT
In the times of Covid-19, face masks are considered to be the main source of protection against the virus that reduces its spread. These masks are classified as single-use medical products with a very short service life, estimated at few days, hence millions of contaminated masks are generated daily in the form of hazardous materials, what requires to develop a safe method to dispose of them, especially since some of them are loaded with viruses. 3-ply face masks (3PFM) represent the major fraction of this waste and are composed mainly from polypropylene and melt blown filter with high content of volatile substances (96.6 wt.%), what makes pyrolysis treatment an emerging technology that could be used to dispose of face masks and convert them into energy products. In this context, this work aims to study pyrolysis kinetic behaviour and TG-FTIR-GC-MS analysis of 3PFM. The research started with analysis of 3PFM using elemental analysis, proximate analysis, and compositional analyses. Afterwards, TG-FTIR system was used to study the thermal and chemical decomposition of 3PFM analyzed at different heating rates: 5, 10, 15, 20, 25, and 30 °C/min. The GC/MS system was used to observe the synthesized volatile products at the maximum decomposition temperatures. After that, isoconversional methods, the advanced nonlinear integral isoconversional method, and the iterative linear integral isoconversional method were used to determine the activation energies of mask pyrolysis, while the distributed activation energy model and the independent parallel reactions kinetic model were used to fit TGA and DTG curves with deviations below <1. The TGA-DTG results showed that 3PFM can decompose in three different periods with a total weight loss of 95 % and maximum decomposition in the range 405-510 °C, while the FTIR spectra and GC-MS analysis exhibited that - C-H (aromatic and aliphatic) and 2,4-Dimethyl-1-heptene (28-43 % based on heating rate) represented the major compounds in the released volatile components. Finally, Vyazovkin and the iterative linear integral isoconversional methods gave activation energies almost similar to that obtained by the KAS isoconversional method.