A pilot-scale experimental study on MILD combustion of sawdust and residual char solid waste blend using low-temperature preheating air

The treatment of solid waste through incineration has become an important development trend. A solid waste blend (sawdust and residual char) is studied experimentally in a tubular-furnace reactor and a 200-kW pilot-scale furnace under moderate or intense low-oxygen dilution (MILD) combustion conditions. The effects of temperature and oxygen concentration on NO release characteristics are examined in the tubular-furnace reactor. The pilot-scale furnace experiments include the conventional flame combustion using a swirl nozzle (CFC-S), MILD combustion using symmetrical dual straight nozzles (MILDC-SD), and MILD combustion using an asymmetrical single straight nozzle (MILDC-AS). The tubular-furnace reactor results indicate that the NO released from solid waste blend mainly originates from fuel-NO under medium temperature and low oxygen environments. The pilot-scale furnace results demonstrate that stable combustion of the solid waste blend can be achieved under three co-combustion conditions. Compared to CFC-S, the MILDC-AS combustion of solid waste blend inhibits the fuel-NO and PM2.5 emissions by 54% and 50%, respectively. The burnout rates of solid waste blend MILD combustion exceed 95%. This study not only extends the fuel adaptability of MILD combustion to solid waste blend, but also proves the suppression influence of MILD combustion on fuel nitrogen and PM2.5 emissions.

Automated summary

The experimental study on the incineration treatment of sawdust and residual char blend in a tubular-furnace reactor and a 200-kW pilot-scale furnace is conducted. The influence of temperature and oxygen concentration on NO release characteristics is examined, indicating that the released NO mainly originates from fuel-NO under medium temperature and low oxygen environments. The results demonstrate that stable combustion and emission reduction can be achieved through MILD combustion of the solid waste blend.