Fuel pellets with antioxidant of illicit cigarette's tobacco auto-generate less CO2, produce adequate flame and are toxicologically reliable

Highlights: • A powerful antiradical for stabilizing self-oxidizable solid biofuel. • Deceleration of kinetics and reduction of off-gassing of CO₂ in 217.40 mg kg⁻¹ • Experiments on combustion, slagging, and harmful and potentially harmful compounds. • Acceptable emissions of noxious volatiles for occupational safety recommendation. • Pelletization as an eco-friendly tobacco-to-biofuel pathway. Our holistic study, firstly, developed pellets with extract of illicit cigarette's tobacco for controlling off-gassing of CO₂ then quantitatively analyzed the implications of this addition to combustion, tendency for slagging and fouling, and toxicology of the final product. The production of pellets consisted of adding 0.10 L of extract at 0.05% v v⁻¹ to 2.00 kg of feedstock by stirring or spraying then pressing on an automatic pelletizer machine at 200.00 MPa and 125.00 °C. The monitoring and quantification of auto-generation of gas from pellets under steady-state atmosphere lasted for one month. Usage of extract by spraying effectively reduced the absolute-growth rate of autoxidation of extractives and activity of off-gassing in 3.70% g⁻¹ pellets d⁻¹ and 217.40 mg CO₂ kg⁻¹ pellets d⁻¹, respectively, but slightly accelerated the combustion, tended more to slagging and fouling, and increased the emissions of NO_x, SO₂, and volatile organic compounds. However, solid biofuels met the rigors for manual and automatic wood-burning appliances and contained tobacco-specific harmful and potentially harmful compounds nearly an order of magnitude below toxicant levels of occupant discomfort and sensory irritation. Our findings are timely and provide valuable knowledge on the ability of the extract to function as an alternative radical terminator and thus considerably decelerate the time-dependent activity of off-gassing. This antioxidant will open up the horizons for utilization of pellets as solid biofuels in cleaner and safer bioenergy producing systems and assist with tackling environmental and social consequences of spontaneous generation of gases and explosions in home-made and industrial settings.