Light driven depolymerization of tobacco waste: A multi-scale simulations

The photolysis process of tobacco waste holds significant implications for energy and toxic substance reclamation. Via real time time-dependence density functional theory ( RT-TDDFT) calculations and ReaxFF molecular dynamic ( MD) simulation, this study examined how different photolytic conditions influence the depolymerization of tobacco waste. It was discovered that tobacco depolymerization is primarily governed by bond energy and external energy density, rather than specific depolymerization conditions. Among them, the photolysis of nicotine effectively mitigates the formation of the toxic compound C2H5N and facilitates its conversion into nontoxic byproducts. Furthermore, analysis of product distribution under various photolytic conditions suggests that photolysis mitigates secondary reactions of volatiles during tobacco waste depolymerization, promoting the production of lighter tars and enhancing the potential for high-value chemical transformation. The pathways of product formation vary under different illumination conditions: continuous illumination primarily yields products from cellulose cleavage, while laser irradiation mainly triggers free radical reactions. Ultimately, an analysis of reaction frameworks under diverse photolytic conditions reinforces these conclusions.