Multiple hearth apparatus and process for thermal treatment of

Abstract

A multiple hearth reactor apparatus and process for the thermal treatment of organic carbonaceous materials under controlled pressure and temperature comprising in accordance with one embodiment, a pressure vessel containing a plurality of superimposed annular hearths including a series of upper hearths defining a preheating zone and a series of lower hearths spaced therebelow defining a reaction zone. The reactor is provided with an inlet for introducing a moist carbonaceous feed material under pressure into the preheat zone and the feed material is transferred downwardly in a cascading manner through the preheat zone and reaction zone. The solid product is extracted from the lower portion of the apparatus while waste water and product gas are extracted from the preheat zone. The hot gases are passed in countercurrent fashion to effect a preheating of the feed material. In accordance with a second embodiment of the apparatus, a separate chamber is employed for preheating of the feed material and the preheated and partially dewatered feed material is thereafter directly charged into the multiple hearth apparatus defining the reaction zone. In operation, the apparatus is adapted to operate at temperatures ranging from about 200.degree. F. up to about 1200.degree. F. or higher at pressures generally ranging from about 300 up to about 3000 psig. Residence times of as little as 1 minute up to about 1 hour or longer can be employed depending upon the nature of the feed material and the desired thermal restructuring.