Thermogravimetric characteristics and pyrolysis kinetics of Alga Sagarssum sp. biomass

Alga Sagarssum sp. can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics and kinetics of Sagarssum sp. were investigated using a thermogravimetric analyzer and tubing reactor, respectively. Sagarssum sp. decomposed below 550 °C, but the majority of materials decomposed between 200 and 350 °C at heating rates of 5–20 °C/min. The apparent activation energy increased from 183.53 to 505.57 kJ mol−1 with increasing pyrolysis conversion. The kinetic parameters of Sagarssum sp. pyrolysis were determined using nonlinear least-squares regression of the experimental data, assuming second-order kinetics. oposed lumped kinetic model represented the experimental results well and the kinetic rate constants suggested a predominant pyrolysis reaction pathway from Sagarssum sp. to bio-oil, rather than from Sagarssum sp. to gas. The kinetic rate constants indicated that the predominant reaction pathway was A (Sagarssum sp.) to B (bio-oil), rather than A (Sagarssum sp.) to C (gas; C1–C4).