Study On The Particulate Matter Formation Characteristics During Ammonia Co-combustion With Biomass

Previous studies have shown that mixing ammonia with other fuels can improve the ignition characteristics and improve the reactivity,but there is no clear certainty about the flame stability and pollutant emission characteristics in the process of co-firing ammonia with solid fuel.The results show that co-combustion of ammonia and biomass is feasible,but the impact of co-firing of ammonia on the generation of particulate matter is not clear,and further separation of variables is needed to explore.Through the study in a one-dimensional furnace,it is found that the mixing of ammonia has a greater impact on the temperature and gas composition in the furnace,so a flat-flame burner is built,three gas temperatures and three ammonia mixing ratios are set,and the water-cooled sampling tube is used to collect particles in the flue gas above the burner.It was found that the concentrations of PM₁ and PM_1～10in flue gas increased with the decrease of temperature.The increase of PM_1～10concentration is caused by the weakening of particle sintering degree.At low temperature,there are a large number of flocs adhered to the PM,resulting in the increase of PM_1～10 concentration with the decrease of temperature;The increase of PM₁ concentration is due to the decrease of temperature and the increase of the condensation driving force of inorganic vapor in the gas phase,resulting in more particles forming nano-particles through homogeneous condensation.The increase of ammonia mixing ratio has a greater impact on PM₁ concentration,and a smaller impact on PM_1～10 concentration.The increase of PM₁ concentration is mainly due to the reaction of nitrogen oxides and water vapor with inorganic vapor in the gas phase,to generate nitrate compounds,resulting in the increase of PM1concentration;The micromorphology of PM_1～10 changes with the increase of ammonia doping ratio.The higher the ammonia doping ratio,the more flocs adhered around the particles,which may be caused by the impact of many fine particles on the surface of large particles due to the increase of PM₁ concentration.Through the experiment,it is found that co-firing ammonia has a great impact on fine particles.The nitrogen oxide and water vapor in the gas phase will cause the concentration of fine particles to rise.Therefore,it is also worth paying attention to the problem of causing the concentration of particles to rise after co-firing ammonia.