Production of bio-oils enriched with aroma compounds from tobacco waste fast pyrolysis in a fluidized bed reactor

As tobacco waste production from tobacco industry increases, it becomes important to convert tobacco waste into high value-added products. In this paper, the production of aroma compounds from the fast pyrolysis of tobacco waste was investigated, two kinds of tobacco waste-tobacco leaf fragments (TF), tobacco stems (TS)-and Modeng-brand cigarette tobacco (MT) were used as raw materials in a fluidized bed pyrolysis reactor. Tobacco types, pyrolysis temperatures, and bio-oil separation methods were assigned as influence factors, and the type and content of bio-oil-containing aroma compounds were defined as evaluation standards. Our results indicate that (i) the bio-oil yield under the same pyrolysis temperature (350 degrees C) is TS > MT > TF; (ii) when TF and MT are used as raw materials, low-temperature (about 350 degrees C) pyrolysis is beneficial for the production of aroma compounds, whereas TS requires higher temperature (more than 380 degrees C) pyrolysis; and (iii) bio-oils obtained from different separation methods contain different kinds of aroma compounds, with some compounds requiring certain separation methods. The formation and pyrolysis mechanism of nitrogen (N)-containing compounds in tobacco was also studied. The study demonstrated that nicotine converts to N-containing heterocycles because of secondary decomposition under high temperature. Graphical abstract

Automated summary

The study focused on converting tobacco waste into high value-added products through fast pyrolysis, with TF, TS, and MT used as raw materials. The bio-oil yield was found to be TS > MT > TF under the same pyrolysis temperature of 350 degrees C. Different separation methods for bio-oils resulted in different types of aroma compounds, with some compounds requiring specific separation methods.