Abstract:
In order to make full use of the
Phragmites australis as biomass energy, pyrolysis test for
Phragmites australis stalk was performed at different heating rates. The kinetic parameters of
Phragmites australis pyrolysis were calculated by Coats-Redfern(CR) method, Flynn-Wall-Ozawa(FWO) method and Kissinger-Akahira-Sunose(KAS) method. The results showed that the pyrolysis of
Phragmites australis stalk could be divided into four stages, of which the stage of 190-400℃ was the main pyrolysis stage. At this stage, comparing the conversion rate(
α)calculated from the three methods with the experimental data, it was found that the deviation between the calculated values of the Coats-Redfern method and the experimental data was larger when the temperature was more than 250℃. The conversion rates obtained by using Flynn-Wall-Ozawa method and Kissinger-Akahira-Sunose method were in good agreement with the experimental values at the whole pyrolysis stage. According to the master-plots method, the optimal reaction mechanism of pyrolysis was random nucleation and the reaction series was 2.It was found that the Kissinger-Akahira-Sunose method was more suitable for calculating the kinetic parameters of
Phragmites australis stalk pyrolysis compared with the Flynn-Wall-Ozawa method. The apparent activation energy calculated by the Kissinger-Akahira-Sunose method increased first and then decreased with the increase of conversion rate. And the activation energy reached the maximum(286.9 kJ/mol) when the conversion rate was 50%.