Combustion behaviors of three bamboo residues: Gas emission, kinetic, reaction mechanism and optimization patterns

This study focused on the assessment of gas emissions and bioenergy potential of the combustions of bamboo leaves (BL), shoot leaves (BSL) and branches (BB) in the air atmosphere. The main combustion stage of the three residues occurred at between 200 and 600 degrees C, with three peaks of mass loss. The pattern of mass loss rate was BSL > BB > BL, with BSL having the best combustion characteristic parameters. The main evolved gases were CO2 and H2O at between 200 and 600 degrees C. Organic gaseous compounds were decomposed in the range of 200-400 degrees C. Air pollutants were produced in the range of 200-500 degrees C. N-containing gas pollutants were 0.01-0.1 times CO2, while SO2 was produced in a very small amount. BL produced more gas pollutants than did BSL and BB, while the controls over the gas pollutants should be more concentrated in the range of 200-400 degrees C. The joint optimizations of derivative thermogravimetry, differential scanning calorimetry, remaining mass, and conversion degree showed 653.2 degrees C and 5 degrees C/min as the optimum operational conditions for bioenergy utilization, while BB performed as the best feedstock. Among three iso-conversion methods used to estimate activation energy, Flynn-Wall-Ozawa led to best correlation. The Coats-Redfern method pointed to the second order reaction model (f (alpha) = (1-alpha)(2)) as the most likely reaction mechanism. Overall, the bamboo residues were promising as the environmentally friendly and renewable feedstock. Our findings can provide the basis for bioenergy generation, pollution control, and optimal efficiency when the industrial-scale combustions of the bamboo residues are adopted. (C) 2019 Elsevier Ltd. All rights reserved.