Process optimization for the valorization of plastic waste into fuel additive production under the zero waste concept

Synthetic plastic, generally derived from the petrochemical industry, is classified as a high molecular weight material and mostly contains branch and crosslinked polymer structures. However, it cannot be decomposed naturally, which causes a global warming crisis. Therefore, in this research, a fuel additive was prepared from thermoplastic polycarbonate via catalytic methanolysis. Furthermore, statistical response surface methodology (RSM) was applied to obtain process optimization under various reaction times, sodium hydroxide (NaOH) concentrations, and methanol contents. After the reaction, a fuel additive of dimethyl carbonate (DMC) was separated by filtration and distillation. The results revealed that the optimum reaction time (40 min), 0.5 g of NaOH, and 30 g of methanol were obtained. Successfully, a 3.5 g DMC yield, which was equivalent to more than 95% DMC yield, was achieved. The characterization of DMC was also analyzed by Fourier transform infrared spectroscopy. The functional groups of O–H, C–H, C = O and C-O were sequenced in the form of wave frequencies of 3318.46 cm−1, 2963.33 cm−1, 1726.84 cm−1 and 1274.04 cm−1, respectively. Interestingly, the valorization of synthetic plastic waste into fuel additive was achieved under the zero waste concept.