Optimizing the distribution of pyrolysis syngas from bio-oil distillation residue by adding bituminous coal under different induction conditions

In this study, bituminous coal was added as an additive to the pyrolysis of bio-oil distillation residue in order to optimize the production of pyrolysis syngas using a lab-scale fixed pyrolysis reactor. Response surface methodology was introduced to investigate the main and interaction effects of induction conditions (the percentage of bio-oil distillation residue, pyrolysis temperature and gas flow rate) on syngas based on central composite design. The results showed that the quadratic model was the optimal model to describe the yield and distribution of syngas through statistical analysis. All induction conditions were favorable for the yield of syngas, while had different effects on the syngas distribution. Among them, temperature had the greatest influence on the yield of different components of syngas, and the percentage of bio-oil distillation residue played a secondary role. Meanwhile, pyrolysis temperature contributed to the formation of hydrogen and methane, while it exhibited a negative linear effect on carbon monoxide and a negative parabolic effect on carbon dioxide. Optimized experimental conditions were recommended and further validated for maximum hydrogen, carbon monoxide, methane and minimum carbon dioxide, respectively. The highest calorific value of syngas (16.82 MJ/Nm(3) ) was obtained by adding 40% bituminous coal under 550 degrees C and the gas flow rate of 500 ml/min. And the corresponding yields of biochar, bio-oil and syngas were 48.16%, 29.98% and 21.86%, respectively.