The Influence of Addition of Expired Pharmaceuticals on Thermal Behaviour of Selected Types of Biomass

The influence of 2 wt.% additives of expired paracetamol and naproxen on the thermal behaviour of densified samples of pea husks (PH), corncobs (CC), and sunflower inflorescences (SI) was studied using an analytical TG/FTIR unit. Gaseous, liquid, and solid pyrolysis products were evaluated using XRD, SEM, and EDX techniques along with FT-IR, ATR, and UV spectroscopies. It was found that the additives changed the yield and composition of pyrolysis products differently. The addition of paracetamol increases the contribution of guaiacyl rings in the condensed material of all samples, and the addition of naproxen—that of chromophores originating from the decomposition of lignin. The additives diversely affected the contribution of hydrocarbons in the composition of volatile products of pyrolysis: they decreased this contribution in PH samples, increased it in SI samples, and did not change in CC samples. The additives used changed the morphology and composition of organic and inorganic parts of pyrolyzed biomass. These changes in inorganics caused the changes in the composition of pyrolysis products. The conducted research proves not only the possibility of the utilization of expired pharmaceuticals during their pyrolysis with densified PH and CC samples but also the ability to reduce the undesirable hydrocarbons in the obtained volatile products.