ABSTRACT
Pyrolysis of medical waste components combined via a novel systematic combination approach (sequentially binary, ternary, and quaternary copyrolysis) was conducted at 400°C to investigate the synergy between medical waste components in improving chemical characteristics and yields of pyrolytic oil. Pyrolysis of hydrocarbon-polymer-containing materials such as medical gloves and rubber bands produced more than 30% of liquid products with substantial compositions of saturated aliphatic hydrocarbon polymers. On the other hand, moisture- and carbonyl-rich pyrolytic liquid products with low selectivity were obtained from pyrolysis of lignocellulosic biomass waste such as HVS paper (houtvrij schrijfpapier, meaning "writing paper made from wood pulp”) and garden waste. Binary copyrolysis of lignocellulosic biomass and medical gloves exhibited improvement on pyrolytic liquid yield and selectivity toward saturated aliphatic hydrocarbon polymers due to hydrogen donor as the medical glove fraction became dominant. The addition of rubber band to the mixture of HVS paper and medical face masks enhanced the pyrolytic liquid yield. The pyrolysis of the mixture of HVS paper, medical face masks, medical gloves, and either rubber bands or cotton fabrics with mixture ratio of 60:20:10:10 yielded the most optimum pyrolytic liquid yield with significant distribution of alkanes in the pyrolytic liquid products. © 2023 Taylor & Francis Group, LLC.
ABSTRACT
The disastrous impact of COVID-19 pandemic has caused a significantly increased production and use of pharmaceutical drugs, which is accompanied by the rapid generation of waste pharmaceutical blisters (WPBs). Nonetheless, its treatment has not gained appropriate attentions and a perceptible process development was not achieved. In this study, the WPBs pyrolysis in CO2 atmosphere was conducted as well as the thermodynamics and kinetics were investigated. The thermogravimetric analysis revealed that the WPBs decomposition could be divided into two stages of 25 - 365 °C and 365 - 900 °C with mass loss of 56.5 - 60.5 wt% and 22.5 - 25.9 wt%, respectively. Fourier-transform infrared spectroscopy analysis indicated the dechlorination process initiating at â¼300 °C. The simultaneous asymmetric stretching of HCl and stretching vibration of C-Cl bond was detected in the range of 2600 - 3250 cm-1 and 660 - 750 cm-1, respectively. The dechlorination reactions were almost complete at â¼520 °C and minor peaks (2900 -3100 cm-1) due to C-H vibrations were observed. Gas chromatography-mass spectrometry analysis indicated that the evolved products included alkanes, benzene, olefin, as well as HCl. The cycloalkenes content significantly increased during the second conversion stage, implying the addition reactions between alkanes and olefins. The apparent activation energy was calculated using three model-free methods and the values from Flynn-Wall-Ozawa model increased from 142.0 to 255.8 kJ·mol-1 with an average value of 147.4 kJ·mol-1. The methods of Coats-Redfern as well as Malek were applied to determine the reaction mechanism. The one-dimensional diffusion model was more reliable to describe the WPBs pyrolysis. This study will represent a significant reference case for the thermochemical conversion of multilayer packing waste and facing the increasing demand for the medical waste recycling.
ABSTRACT
COVID-19, a condition associated with severe acute coronavirus two respiratory syndromes (SARS-CoV-2), has impacted the lives of billions of people worldwide. Scientists around the world are trying to find ways to cure the disease in the vaccine strain. Out of all essential prerequisites for the health workers and doctors, Personal protect tion equipment (PPE) has acted as an essential part of the virus's protection purpose. While PPE kits are reported to provide adequate protection against pathogens, their removal can have a devastating impact on the environment. National authorities ensure the proper elimination of PPE following the guidelines provided by the WHO. The plethora of PPE kits will further boost the polymer load on our planet. This re- view represents a scheme for disposing of PPE kits by converting them into alternate fuel through solar thermal engineering.
ABSTRACT
COVID-19 pandemic has brought tremendous environmental burden due to huge amount of medical wastes (about 54,000 t/d as of November 22, 2020), including face mask, gloves, clothes, goggles, and sanitizer/disinfectant containers. A proper waste management is urgently required to mitigate the spread of the disease, minimize the environmental impacts, and take their potential advantages for further utilization. This work provides a prospective review on the possible thermochemical treatments for those COVID-19 related medical wastes (CMW), as well as their possible conversion to fuels. The characteristics of each waste are initially analyzed and described, especially their potential as energy source. It is clear that most of CMWs are dominated by plastic polymers. Thermochemical processes, including incineration, torrefaction, pyrolysis, and gasification, are reviewed in terms of applicability for CMW. In addition, the mechanical treatment of CMW into sanitized refuse-derived fuel (SRDF) is also discussed as the preliminary stage before thermochemical conversion. In terms of material flexibility, incineration is practically applicable for all types of CMW, although it has the highest potential to emit the largest amount of CO2 and other harmful gasses. Furthermore, gasification and pyrolysis are considered promising in terms of energy conversion efficiency and environmental impacts. On the other hand, carbonization faces several technical problems following thermal degradation due to insufficient operating temperature.