Analytical and\nApplied Copyrolysis of Mesua ferrea L. and Polyethyelene Terephthalate Plastic\nfor Hydrocarbon-Rich Bio-oil

The current investigation focuses on the copyrolysis\nof Mesua ferrea L. (a nonedible oilseed,\nalso known\nas Nahar) and polyethyelene terephthalate (PET) plastic waste to gain\ninsights into the composition of pyrolysates and the thermal decomposition\nof complex and mixed feedstocks. The physicochemical properties of\nthe feedstocks were studied through thermogravimetric analysis at\na heating rate of 15 °C min<sup>–1</sup>, bomb calorimetry,\nand proximate/ultimate analysis. The proximate analysis revealed that\nboth biomass and PET had relatively low moisture contents (3.33 and\n0.61%, respectively) and high volatile matter (88% for biomass and\n94.53% for PET). The pyrolysate composition studies using analytical\npyrolysis coupled with a gas chromatograph/mass spectrometer revealed\nsignificant generation of fatty acids (∼79%) from Nahar and\nbenzoic acid (24%) and acetylbenzoic acid (15.5%) from PET at 590\n°C. The analytical pyrolysis of feedstock mixtures at biomass:PET\n(B:P) of 1:1, 2:1, and 1:2 w/w revealed the dominance of both aliphatic\nand carboxylic acids. Further, fixed-bed copyrolysis experiments were\nperformed using Nahar, PET, and its mixtures in a temperature range\nof 550–650 °C at 15 °C min<sup>–1</sup> heating\nrate. The optimal temperature of 600 °C was chosen for both biomass\nand copyrolysis (2:1 feed ratio) due to the high yield of pyrolytic\nliquid (27 wt % for biomass alone; 35 wt % for copyrolysis). The produced\nbio-oil was thoroughly characterized, and it was found that fatty\nacids and carboxylic acids such as <i>n</i>-hexadecanoic\nacid, octadecenoic acid, octadecanoic acid, and benzoic acid were\nfound in a significant proportion. The mechanism of copyrolysis vapors\nwas studied by analyzing the pyrolysates obtained at different operating\nconditions. Decarboxylation and decarbonylation fatty acid species\nwere found to be typical pathways for the formation of hydrocrabons\nlike hexadecane, pentadecane, heptadecane, and heptadecene.