Process for staged combustion of retorted carbon containing solids

In a process for retorting a carbon containing solid in a retorting zone using a heat carrier material heated by burning particulate retorted carbon containing solids containing residual carbonaceous material which comprises:

• (a) introducing a first fraction of retorted carbon containing solid from the retorting zone into the bottom of a vertical combustion zone characterized by an upwardly flowing gas stream containing oxygen and having a velocity sufficient to raise the particles of carbon containing solid to the top of the combustion zone, whereby the particles are pneumatically entrained and carried upward by the gas stream;
• (b) burning at least part of the carbonaceous residue in said first fraction of retorted carbon containing solid during its passage from the bottom to the top of said vertical combustion zone;
• (c) burning the remaining carbonaceous residue in said first fraction in a fluidized bed containing an atmosphere having at least a stoichiometric amount of oxygen present;
• (d) introducing a second fraction of retorted carbon containing solid directly into the fluidized bed and burning the carbonaceous residue therein, said second fraction being of a generally smaller particle size than said first fraction;
• and
• (e) recovering burned solids from the fluidized bed.