Experimental study on propane combustion in a novel fluidized bed configuration

Experimental study on propane combustion has been performed in a novel fluidized bed configuration. This configuration has a jet that issues vertically in the upper part of the bed while allowing two methods of feeding. The first method is through jetting air–propane mixture that ensures smooth combustion avoiding burning bubble explosion. The second method enables staged-air combustion technique. Initial heating has been carried out by jetting propane partially premixed with air. The remaining part of air is fed through the distributor plate to fluidize bed solids. The proposed configuration enables a rapid and reliable method for initial heating of a fluidized bed combustor. The obtained results demonstrate that by applying the novel configuration, the freeboard overheating is greatly reduced. In accordance, the in-bed cooling load increases with increasing the secondary air ratio when applying the novel configuration. Alternatively, the temperature of the lower part of the freeboard fairly decreases while the temperature of the upper part considerably increases when applying the conventional method of air staging. Additionally the in-bed cooling load was found to significantly decrease with secondary air. The results also indicate that the novel configuration is more effective in reducing NOx. On the other hand, CO didn't exhibit significant change with increasing secondary air ratio applying the novel configuration while CO multiplies in the case of conventional operation. •A novel fluidized-bed configuration enables smooth combustion of gaseous fuels.•A rapid method for initial heating of fluidized-bed combustor was confirmed.•Applying jet-fountain configuration greatly dampens the freeboard overheating.•Staged-air combustion using the novel configuration dampens freeboard overheating.•Staged-air using the novel configuration is more successful in reducing NOx.