FLUIDIZATION CHARACTERISTICS OF BIOBONE PARTICLES USED FOR BIOCATALYSTS

Liquid-solid fluidization characteristics of irregularly shaped Biobon e particles were studied in a fluidized bioreactor column 2.35 m high and 0.1 m dia. The wet biobone particles had a density of 1,890 kg/m(3 ). Two ste ranges were studied: 1.70 - 2.36 mm and 1.25 - 2.36 mm. The Biobone is a natural cheap material composed of collagen, which is a strong protein structure, embedded with microcrystals of hydroxyapatit e and calcium phosphate, and it is an excellent matrix of commercial i mportance used for the immobilization of enzymes, whole cells and othe r biocatalysts. Fluidization characteristics of Biobone particles whic h include measurements of pressure drops, holdups, minimum fluidizatio n velocities, particle entrainment, and resilience time distributions at different water superficial velocities, are reported. Because of th e highly irregular shape of Biobone particles, new fluidization behavi or was observed which was much different from the fluidization behavio r of spherical particles reported in the literature. A new channeling inner, I-c, is proposed to quantify the channeling characteristics of fluidized Biobone particles and a new parameter, alpha, was developed to distinguish the transition between fixed and fluidized states of th e Biobone particles.