Staged heating by oxidation of carbonaceous material

In a continuous process for pyrolyzing a carbonaceous material in which heat for pyrolysis is obtained by partially oxidizing a carbon containing solid residue of pyrolysis in the presence of oxygen to form a particulate source of heat which is combined with the carbonaceous material in a pyrolysis reaction zone to initiate pyrolysis of the carbonaceous material, the improvement comprising the steps of:

• a. at least partially oxidizing in a cyclone combustion-separation zone a portion of a preheated carbon containing solid residue in the presence of oxygen to yield gaseous combustion products including carbon monoxide and form the particulate source of heat while simultaneously separating the particulate source of heat from the gaseous combustion products in the combustion-separation zone
• b. passing the particulate source of heat to the pyrolysis reaction zone to provide at least a portion of the heat required for pyrolysis of the carbonaceous material to produce the carbon containing solid residue;
• c. preheating the carbon containing solid residue of pyrolysis, in a heating stage, by directly contacting the carbon containing solid residue of pyrolysis with at least a portion of the gaseous combustion products formed in the combustion-separation zone from combustion of the preheated carbon containing solid residue;
• and
• d. further heating the preheated carbon containing solid residue of pyrolysis from the heating stage by combining, in a cyclone heating-separation zone maintained at a temperature less than the temperature of the combustion-separation zone, the preheated carbon containing solid residue of pyrolysis and gases from the heating stage with a sufficient amount of oxygen to completely oxidize the carbon monoxide in the gases present in said heating stage while simultaneously separating the further heated carbon containing solid residue of pyrolysis from gases present in the cyclone heating-separation zone for feed to the cyclone combustion-separation zone.

A continuous process for pyrolyzing carbonaceous material comprising the steps of:

• a. directly contacting carbonaceous material with a particulate source of heat comprising carbon containing solid residue in a pyrolysis reaction zone maintained at a temperature greater than about 600.degree. F to yield as products of pyrolysis a pyrolytic vapor and carbon containing solid residue
• b. separating carbon containing solid residue from the pyrolytic vapor;
• c. preheating in a heating zone the separated carbon containing solid residue by:
• i. combining the separated carbon containing solid residue with carbon monoxide containing gaseous combustion products of carbon containing solid residue;
• and
• ii. substantially completely oxidizing the carbon monoxide contained in the gaseous combustion products in the presence at least a stoichiometric amount of oxygen;
• d. separating from at least the bulk of the gases present in the heating zone carbon containing solid residue for feed to a combustion zone;
• e. at least partially oxidizing in the combination zone, a portion of the preheated carbon containing solid residue in the presence of oxygen to yield carbon monoxide containing gaseous combustion products of carbon containing solid residue and form a particulate source of heat;
• f. separating the particulate source of heat from the carbon monoxide containing gaseous combustion products;
• and
• g. recycling at least a portion of the formed particulate source of heat to the pyrolysis zone.