Determination of Plastic Pollutants in Solid Biofuels

Many countries widely use biomass for household heating and heat production in district heating systems. Unfortunately, the steady increase in annual plastic waste production has a negative impact on the quality of solid biofuels. This is due to the increasing contamination of these fuels with wastes from plastic and wastes from furniture production, such as laminates and medium-density fiberboard made from wood fibers, among others. The design of specialized biomass combustion systems does not allow for the burning of waste fuel, or the reduction in hazardous organic compounds emitted when burning contaminated biofuels. The study demonstrated the detection of polymeric impurities in solid biofuels through analytical pyrolysis (Py-GC-MS). The study was conducted on model samples that contained increasing proportions of plastic waste, ranging from 0.1 to 10.0% w/w to biomass. Markers were identified and described to indicate contaminated fuel, and the interactions between the sample matrix and plastic were studied. Unique markers were detected that indicate the presence of contamination, even at low concentrations like 0.1% w/w of plastic waste in solid biofuel. These results suggest that direct analytical pyrolysis of solid biofuels, which are already on the market but not covered by the relevant regulatory system and are contaminated with polymeric ingredients, is a method that is not only possible but also gives quick confirmation.