Kinetic study on pyrolysis of tobacco residues from the cigarette industry

Tobacco is a very abundant bio-based resource in nature, and large amounts of tobacco residues are produced from the cigarette industry, which can be exploited and utilized for energy. In this work, the pyrolysis of tobacco residues including stems and leaves was analyzed by a Thermogravimetric Analysis (TGA) instrument and the corresponding derivative thermogravimetric analysis (DTG). The TGA curves were obtained at the heating rate of 10 °C/min and with temperature range from 25 °C to 700 °C. The results indicated that the pyrolysis of tobacco stems and tobacco leaves included three stages: dehydration, main devolatilization, and continuous devolatilization. More importantly, between the temperature range of 200 °C and 350 °C, by using the Coats–Redfern equation, correlation coefficients of different reaction models describing the pyrolysis of tobacco stems and leaves were predicted, and the best-fit models for different stages of pyrolysis were found. The activation energies as well as frequency factors (A) from the best-fit models were calculated.

► The pyrolysis of tobacco included three stages: dehydration, main devolatilization, and continuous devolatilization.
► Between 200 and 280 °C, reaction model of pyrolysis of tobacco stems and leaves was D1 one-dimensional diffusion.
► Between 280 and 350 °C, D2 two-dimensional diffusion described tobacco stems pyrolysis most well.
► Between 280 and 350 °C, F3/2 1.5 order reaction described tobacco leaves most well.
► The activation energies calculated from those reaction models for tobacco showed relatively lower values than other biomass.