The effects of catalysts on the conversion of organic matter and bio-fuel production in the microwave pyrolysis of sludge at different temperatures

Abstract

Adding catalyst could improve the yields and qualities of bio-gas and bio-oil, and realize the oriented production. Results showed that the catalytic gas-production capacities of CaO were higher than those of Fe₂O₃, and the bio-gas yield at 800°C reached a maximum of 35.1%. Because the polar cracking active sites of CaO reduced the activation energy of the pyrolysis reaction and resulted in high catalytic cracking efficiencies. In addition, the quality of bio-oil produced by CaO was superior to that by Fe₂O₃, although the bio-oil yield of CaO was relatively weak. The light bio-fuel oriented catalytic pyrolysis could be realized when adding different catalysts. At 800°C, CaO was 45% higher than Fe₂O₃ in aspect of H₂ production while Fe₂O₃ was 103% higher than CaO in aspect of CH₄ production. Therefore, CaO was more suitable for H₂ production and Fe₂O₃ was more suitable for CH₄ production.

Keywords: Bio-fuel; CaO catalyst; Catalytic microwave pyrolysis; Fe(2)O(3) catalyst; Sludge.