Energy and exergy characteristics of syngas produced from air gasification of walnut sawdust in an entrained flow reactor

Energy and exergy are two important tools for evaluating energy sources. The energy and exergy of syngas produced from air gasification of walnut sawdust in an entrained flow reactor were detailed for typical reactor temperatures (700, 800, and 900°C) and equivalence ratios (0.22, 0.25, 0.28, 0.31, and 0.34). The results showed that the overall energy distribution was CO > (CH₄, H₂, N₂, C₂H₄) > CO₂ whereas the overall exergy distribution was CO > (CH₄, H₂) > C₂H₄ > N₂ > CO₂. The results that different component gases contributed differently to the energy and exergy of syngas were due to the fact that different component gases had different exergy/energy ratios. However, both the energy and exergy of syngas achieved the highest values at the same reactor temperature and equivalence ratio. The results obtained from this study can help understand the energy and exergy of syngas produced from biomass gasification as well as the effects of reactor temperature, equivalence ratio (ER), and fuel characteristics on the energy and exergy of syngas.