Pyrolysis of tobacco waste: a comparative study between Py-GC/MS and fixed-bed reactors

Abstract

Pyrolysis, which converts waste into high-value products, is an appropriate and safe waste disposal solution for use in the tobacco industry. The properties of such high-value products were examined in the temperature range of 300–700 °C in order to establish the optimum pyrolytic operating settings for tobacco waste using a Py-GC/MS and a fixed-bed reactor. At 700 °C, the lower heat value of gas was 14 MJ/m3. When the three waste products (char, oil, and gas) are balanced, the optimum operating temperature for biomass pyrolysis of tobacco waste is found to be 600 °C. With rising temperatures, nitrogen (N) compounds, which are mostly detected below 500 °C, escape from tobacco waste. Nicotine, pyridines, and N-methyl-2-pyrrolidone are the predominant compounds found in the organic portion of the oil (up to a concentration of 1.2% m/m). Furthermore, the study found that the Py-GC-MS did not detect benzene products, unlike fixed bed reactor pyrolysis. Alkynes decreased from 15.4% to 3.9% as the temperature increased from 300° to 700°C. Alkenes (1.3-pentadien) had the most peak area. Due to the prolonged response time, no alkynes were found. Furan is generated from hemicellulose and cellulose breakdown and diminishes over 600 °C. Furan yield decreased from 5.5% to 2.2% as temperature increased from 400° to 700°C. The presence of phenols at 600 °C may be due to char or volatiles decomposing further. This results of this research are useful throughout the tobacco industry for dealing with cigarette waste.