ABSTRACT
This research aims to develop a new strategy to valorize wasted COVID-19 masks based on pyrolysis to convert them into useful products. First, surgical and FFP2 masks were thermally pyrolyzed at temperatures of 450–550 ºC with the purpose of determining gas, liquid (oil) and solid (char) yields. At low temperatures, solid yield was high, while at high temperatures the gas product was enhanced. The highest yield of liquid was found at an operating temperature of 500 ºC in both surgical and FPP2 masks pyrolysis. The liquid product yields were 59.08% and 58.86%, respectively. Then, the volatiles generated during thermal pyrolysis of residual masks were cracked over sepiolite as catalyst at a temperature of 500 ºC. The catalytic pyrolysis increased the yield of gas product (43.89% against 39.52% for surgical masks and 50.53% against 39.41% for FFP2 masks) and decreased the viscosity of the liquid product. Finally, the effect of sepiolite regeneration and reuse in consecutive pyrolysis tests was examined. Results showed that, with the higher regeneration-reuse of sepiolite, the catalyst was degraded obtaining a liquid product with higher molecular mass. This effect was hardly noticeable in the case of FFP2 masks. © 2022 International Multidisciplinary Scientific Geoconference. All rights reserved.
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.