Analysis on Pyrolysis Characteristics of Seaweed

The pyrolysis characteristics and kinetics of Gracilaria cacalia (a sort of seaweed) belonging to a marine biomass were studied by using the thermogravimetric analysis method, and the experimental results obtained at different heating rates (10, 20, 30℃/min) and particle sizes (0.18, 0.28, 0.45mm) were analyzed. It was found that the non-isothermal weight-loss process of samples is composed of dehydration, holding, rapid weight-loss and slow weight-loss. The changes of the main components of sample were analysed by Fourier transform infrared spectrum (FTIR). The characteristic parameters of pyrolysis at different heating rates were compared, and the releasing index of pyrolysis was calculated as well, showing that the higher the heating rate, the quicker the pyrolysis reaction. The effect of particle size on the pyrolysis is negligible when particle size is less than 0.45mm. The kinetic parameters were calculated by using the Coasts-Redfern method, indicating that the reaction function of pyrolysis mechanism is different from the woody biomass. The kinetic compensation effect exists between the activation energy and the frequency factor.