Research on pyrolysis characteristics of seaweed

Pyrolysis experiments of Enteromorpha clathrata (ENT) (a species of seaweed) have been conducted using a DTG-60H thermal analyzer, and the pyrolysis characteristics obtained at different heating rates (20, 30, 40, and 50 degrees C min(-1)) are analyzed. The results indicate that the nonisothermal mass loss process of samples is composed of dehydration, rapid mass loss, slow mass loss, and solid residue decomposition. The devolatilization stage of ENT starts earlier than that of woody biomass because the basic components in seaweed are preferable for pyrolysis compared to lignocellulosic materials. The FTIR analysis is employed to investigate the changes in the main components of sample, while the TG-MS analysis is used for the gaseous products analysis during the pyrolysis. And because of the difference between the compositions of seaweed and woody biomass, gas formation here is not the same as the one from woody biomass. The characteristic parameters of pyrolysis at different heating rates show that the maximum rate of pyrolysis mass loss, the peak temperature, the initial and final temperature for devolatilization, and the heat release will increase with increasing heating rate. The kinetic parameters are calculated by using the Coats-Redfern method, which indicates that the kinetic function of pyrolysis inechanism is different front the woody biomass. The kinetic compensation effect exists between the activation energy and the frequency factor.