Optimization of Pyrolysis-Separation Process for the Production of Crude Oil from Valorization of Waste Face Masks (WFMs) from Metro Manila, Philippines

In the Philippines, the face mask used in 2020 to prevent the spread of the COVID-19 virus led to a 595% rise in plastic-based medical waste. Current medical waste treatment methods in the country, such as landfilling, chemical disinfection, burial, and vault confinement, either harm the environment or yield no value post-processing. Repurposing is necessary to reduce greenhouse gas emissions and avoid accumulation. In this study, a proposed pyrolysis-separation process utilizes 1 ton per day of waste face masks (WFMs) obtained from nearby hospitals and medical facilities in the Metro Manila area, which is mainly composed of polypropylene (PP) and low-density polyethylene (LDPE). WFM's undergo pretreatment in a hammermill for size reduction. The hammermill fines are fed into a pyrolysis reactor producing vaporized hydrocarbons and solid char. The vapor stream is divided into non-condensable hydrocarbon gases and heavy condensable crude oil through a flash separator. The process was simulated through Aspen HYSYS using two continuous stirred tank reactors (CSTRs), and one separator in a parallel configuration, with PP and LDPE feeds in each configuration. The crude oil product, composed mainly of heavy hydrocarbons, was consistent with commercial standards. Optimization of the proposed pyrolysis-separation process led to the production of 0.97 tons per day crude oil. By utilizing WFMs, the plant is capable of reducing the waste generation of Metro Manila by 330 tons annually.