Laminar Premixed Combustion Characteristic Investigation Of Syngas Derived From Biomass By PLIF And CHEMKIN Simulation

As non-regeneration energy, fossil energy is less and less, and there will produce heavy pollutant in process of use it. So it is necessary to find a renewable and cleanly resource for our human's sustainable development. Biomass as a kind of renewable resource benefits from large storage and widespread is regarded as a good substitute goods. But biomass has low utilization rate in combustion directly, and also produce pollutant. If gasify biomass, we will get cleanly syngas, which has lower calorific value and hard to combustion, so it is important to study the combustion characteristic of syngas.In this context, we used the dominant method in combustion measurement, PLIF?Planar laser induced fluorescence? as research technique, studied the influence of N₂ and CO₂ on H₂ combustion characteristic in different equivalence ratio, including flame structure and concentration of OH, then extended to syngas combustion characteristic in different equivalence ratio, including flame structure, concentration of OH and flame speed. And simulated the combustion temperature, concentration of OH and flame speed of syngas in different equivalence ratio with the software CHEMKIN. Finally, contrasted the experimental results and simulated results, and analyzed the chemical kinetics of caused the changes of temperature and concentration of OH.The experimental results conducted by PLIF we can concluded that:?1? both N₂ and CO₂ would decrease the flame size of H₂ combustion, and change the flame color. But contrast to N₂, CO₂ has heavily decreased the flame size, concentration of OH and flame speed, and the flame color was baby blue.?2? The CO in the syngas had heavy influence on flame structure and concentration of OH, with the add of CO, the height of inner flame increased and the inner flame was brighter, the concentration of OH of concentrated in the flame front and decreased the diffusive combustion of H₂, especially in low equivalence ratio.?3? The flame speed of sgngas increased with the equivalence ratio increase, but the increased range vary directly as H₂ concentration, and CO would boost the flame speed.The results of simulation as follows:?1?thehighest temperature and concentrationof OH in H₂/N₂ and H₂/CO₂ combustion was equivalent ratio in 1.0, but with add of CO, thehighest temperature and concentrationof OH in syngas combustion was equivalent ratio in 1.2.?2?Although CO in the syngas can not produce OH, it would promote the product of OH.?3? The elementary reaction that influence the temperature of syngas combustion is R36:CO+OH=CO₂+H, and with increase of equivalence ratio, elementary reaction transfer to R45:H+HO₂=2OH from R36.?4? There are three reactions influence the product of OH, they are R36:CO+OH=CO₂+H,R43:H+O₂+M=HO₂+Mand R45:H+HO₂=2OH.