Optimization and Analysis of Pyrolysis-Supercritical Fluid Extraction for Tobacco Waste Biomass

A large amount of tobacco product waste is discarded directly, resulting in a waste of resources and environmental issues. Nicotine is a natural organic compound found in tobacco waste. As an important substance in treating neurological disorders, it is of high market value. Pyrolytic and supercritical fluid extraction is a method to extract nicotine from tobacco waste. We used the orthogonal experimental method to optimize the pyrolysis process of tobacco waste and found the optimal pyrolysis conditions to be the temperature of 450°C, time of 3 h, and catalyst ratio of 1:1.5. The mathematical model of extraction conditions and extraction rate of supercritical fluid extraction was established with R2 = 0.9884. This model showed that the extraction rate of nicotine could reach as high as 70.53%. The optimal conditions for nicotine extraction included the entraining agent concentration of 70%, temperature of 45°C, pressure of 30 MPa, and time of 2 hours. We also carried out response surface analysis to explore the relationship between extraction conditions and the extraction rate. According to our findings, entrainer concentration has a strong relationship with pressure. Ethanol can alter the microstructure of the substrate, increasing its porosity and thus reducing the embedding or adsorption depth of the nicotine molecules. As a result, the nicotine extraction efficiency is improved. Compared with traditional nicotine extraction process, the pyrolysis and supercritical fluid extraction has a higher extraction efficiency and less pollution.