Patent ID: 6117199
Filing Date: 2000-09-12
Classification: C10J,C10K

Abstract:
A method of gasifying carbonaceous material in a single fluidized bed reactor having:a lower part defining an oxidation zone, and including a distribution plate;and an upper part defining a reducing zone and including a gas discharge opening;said method comprising the steps of substantially continuously:(a) introducing oxygen containing gas into the lower part of the reactor through the distribution plate;(b) introducing carbonaceous material to be gasified into the reducing zone in the upper part of the reactor at a point substantially free of oxygen, so that the carbonaceous material is pyrolyzed to produce gases which flow through the gas discharge opening;(c) separating unreacted carbonaceous material from the gas flowing through the gas discharge opening;(d) returning the separated unreacted carbonaceous material from step (c) to the oxidation zone below the point of introduction of the carbonaceous material in step (b) so that the unreacted carbonaceous material reacts with oxygen introduced in step (a) to generate heat, CO.sub.2 and H.sub.2 O and to maintain a temperature of between 970-1200 degrees C in the oxidizing zone;(e) circulating a sufficient volume of inert particulate material, entrained in gas within the reactor so as to carry sufficient heat from the oxidizing zone into the reducing zone to maintain the temperature in the reducing zone greater than or equal to 900 degrees C to provide a high enough temperature to effect the pyrolyzation of step (b), generated CO.sub.2 and H.sub.2 O and other gases passing upwardly with the circulating particles into the reducing zone from the oxidizing zone to heat the reducing zone; and(f) separating inert particles which pass out of the gas discharge opening with the gas from the gas, and returning the separated inert particles to the oxidizing zone.