Co-pyrolysis kinetics and behaviors of kitchen waste and chlorella vulgaris using thermogravimetric analyzer and fixed bed reactor

Co-pyrolysis of CV and KW under CO2 atmosphere were studied in this paper. The pyrolysis characteristics were investigated by thermogravimetric analysis and the kinetic parameters were calculated by Ozawa-Flynn-Wall and the Kissinger-Akahira-Sunose methods. Results showed that with the increase of mixing degree, the averaged apparent activation energy (Eave) increased evidently, the 50%CV50%KW sample showed the highest Eave (234.43 kJ/mol (OFW) and 228.21 kJ/mol (KAS)). Yields of liquid, solid and gas at different pyrolysis temperature and blends were obtained by a lab-scale fixed bed reactor. Both KW and CV had the highest bio-oil yield at 600 °C in the range of 500-700 °C. Mixing KW and CV deteriorated the bio-oil yield but improved higher heating value of the bio-oil product (33.9 MJ/kg at 600 °C in 5:5 ratios). The gas chromatography-mass spectrometry analysis of bio-oil product further found that co-pyrolysis of CV and KW could decrease carboxylic acids and increased hydrocarbons of bio-oil products. In brief, co-pyrolysis of CV and KW could be a potential way for improving quality and calorific value of pyrolysis oil.