Patent ID: 7261811

Claim:
A gas-liquid-solid circulating fluidized bed system, comprising: a first fluidized bed; solid particles having effective immobilized bacteria coated thereon, means to feed said solid particles having effective immobilized bacteria coated thereon into said first fluidized bed adjacent to a first end of said first fluidized bed and means to feed a first fluid into said first fluidized bed adjacent to a second end of said first fluidized bed, said second end being remote from said first end so that said solid particles and said first fluid flow in counter current, a clarifier means in flow communication with said first fluidized bed for separating solid particles from fluid and exhausting such separated fluid to provide separated solid particles which settle back into the first fluidized bed in order to minimize the loss of particles through the effluent; a second fluidized bed, said second fluidized bed being a riser fluidized bed wherein a means for introducing solid particles and a means for introducing a second fluid into said second fluidized bed are both adjacent to one end of said second fluidized bed so that said solid particles and said second fluid introduced into said second bed flow concurrently through said second bed from said one end toward another end of said second fluidized bed remote from said one end, gas injection means to inject gas into one or both of the first and second fluidized beds; a fluid-solid separator means in flow communication with said riser fluidized bed for separating said solid particles from the second fluid and exhausting the separated second fluid to provide separated solid particles; first means connecting said first fluidized bed to said second fluidized bed adjacent to said second end of said first fluidized bed and said one end of said second fluidized bed, said first connecting means includes means to feed said solid particles into said second fluidized bed; and second means connecting said first and said second fluidized beds adjacent said first end of said first bed and said other end of said second fluidized bed, said second connecting means includes said means to feed the solid particles into said first fluidized bed.