(741f) Cold Flow Analysis of a Coal and Biomass Bubbling Fluidized Bed Gasifier

Bubbling fluidized-bed reactors are a promising technology for the clean conversion of coal into value-added chemicals and gaseous fuels for transportation or electricity generation This study presents the fluidization hydrodynamics inside a 1.5-inch diameter cold-flow rig with geometry similar to an actual high-temperature bubbling fluidized-bed reactor.The binary mixtures investigated consisted of two different feedstocks (hardwood particles and Eastern Appalachian coal) and two different bed materials (glass beads and silica sand). The measurements included the bed pressure drop, normalized bed pressure drop, minimum fluidization velocity for several bed aspect ratios, particle diameters, skeletal and bulk densities, and voidage. Dried and non-dried biomass and initially non-mixed or premixed mixtures were investigated to observe the effect of the moisture content and mixing, respectively, on the fluidization hydrodynamics. Moreover, biomass particles had a wide range of particle size and sphericity compared to the narrower distribution range for the glass beads, silica sand, and coal particles. The graphically-determined minimum fluidization velocity was not affected by the aspect ratio fordried biomass. However, the adhesion effects of biomass particles on the minimum fluidization velocity was evident when the bed aspect ratio increased.The coal mixtures have better fluidization quality due to higher bulk densities and lower voidage ratios compared to the biomass mixtures.