Pyrolysis of Tobacco Rob: Effect of Particle Size on Kinetic Study and Fuel Gas Yield and Composition

During pyrolysis of tobacco rob (TR), the operating parameters such as the temperature, the heating rate, residence time, and particle size affect the process and result of the pyrolysis. Some of these parameters have been closely considered, but the particle size of TR is often ignored. In this study, the size of TR particle was considered as a major factor in determining the mass loss in thermogravimetric analysis (TGA) and product yield and composition at different reactor temperatures in the fixed-bed reactor. The TGA results showed that the conversion rate increased and the activation energy decreased with a decrease in particle size. The experiments demonstrated that fuel gas yield increased with a decrease in particle size, while char and tar yield decreased. Smaller particle sizes resulted in higher H2 and CO contents. Minimizing the size of raw materials is an alternative method to improve the gas quality of TR pyrolysis. The increase of gas yield was attributed to the decomposition of char and tar vapor as temperature increased. Moreover, the performances of the shredder for the breakage of the TR, such as the effect of the rotor velocity and hydraulic pressure on product size distribution was investigated. The results showed that with hydraulic pressure increasing, size distribution of product was finer. When hydraulic pressure was constant, the products size distribution was coarser with increasing rotor velocity.