Patent ID: 7842110

Claim:
A process for producing a product gas having heat or fuel value comprising: feeding a carbonaceous material to a fluidized bed located in a first apparatus, the fluidized bed containing particles suspended in a fluid medium, the fluidized bed including a top portion and a bottom portion, the bottom portion being in communication with a solids collection reservoir located below the bottom portion and separate from the first apparatus in which the fluidized bed is located; indirectly heating the fluidized bed with a pulse combustion device, a portion of the carbonaceous material fed to the fluidized bed being gasified to form a product gas stream; receiving bed solids from the fluidized bed directly into the solids collection reservoir; and feeding a gaseous medium through the solids collection reservoir and into the bottom portion of the fluidized bed, the gaseous medium comprising an oxygen-containing gas, wherein: the solids collection reservoir is maintained at a higher temperature than the fluidized bed; and a first portion of carbon particles within the bed solids received into the solids collection reservoir is oxidized and a second portion of the carbon particles is endothermically converted to a gas.