Thermogravimetric kinetics and pyrolytic tri-state products analysis towards insights into understanding the pyrolysis mechanism of Spirulina platensis with calcium oxide

Abstract Thermogravimetric kinetics and pyrolytic tri-state products analyses towards insights into understanding the pyrolysis mechanism of Spirulina platensis with calcium oxide were investigated using a thermogravimetric analyzer and a fixed bed reactor, respectively. The pyrolysis kinetics were studied by Friedman method and results indicated that the f(α)=(1-α)4 with A0 = 1.99E+10s−1 and f ( α ) = − 1 / l n ( 1 − α ) with A0 = 8.33E+11s−1 were suitable for Spirulina platensis and Spirulina platensis + CaO (stage II) pyrolysis, respectively. According to pyrolysis behaviors and kinetics analyzed, the potential reaction behaviors of CaO during the pyrolysis of Spirulina platensis were explored. Spirulina platensis pyrolytic tri-state products analyzed indicated that, when CaO as additive, the gas yield markedly increased with more H2, CO content and less CO2 content and the bio-oil yield significantly decreased. Moreover, the contents of aromatic compounds, aliphatic compounds, phenols and ketons obviously increased in bio-oil with the appreciably decreased in the contents of esters, N-containing compounds, O-containing compounds and acids. Based on the evolutionary mechanism of CaO and pyrolytic tri-state products, the pyrolysis mechanism of Spirulina platensis with calcium oxide was proposed.