Co-pyrolysis behavior of microalgae biomass and low-rank coal: Kinetic analysis of the main volatile products

Abstract

This work studied the kinetic characteristics of volatile products from co-pyrolysis of microalgae and low-rank coal. Iso-conversional method was applied to calculate the reaction order, activation energy and pre-exponential factor of gaseous products (H2, CO, CH4, and CO2) and benzene. The results indicated the activation energy of H2 generating from both individual and mixing samples was the highest, meaning H2 was the hardest to generate during the pyrolysis process. The values of activation energy from the formation of CO and benzene from low-rank coal and green algae were 31.11, 32.44, 18.21 and 24.31 kJ·mol−1, respectively. The formation of benzene and CO were easier than other volatile products due to the lower activation energy. Synergistic effects were observed from the formation of CO2, the addition of green algae decreased the activation energy. The order of the activation energy was in agreement with that of the releasing sequence of main volatile products.