Method And Apparatus For Producing A Carbonaceous Residue Product
A carbonaceous residue or char having novel properties is produced from particulate agricultural waste material, such as peanut shells, which upon heating exhibits an exothermic decomposition into an off gas component and a solid component in which the off gas component is more highly reactive to oxygen than is the solid component. By introducing air into the reaction zone whereat the decomposition is effected and controlling the amount of air so introduced such that not all of the off gas component may be oxidized, the preferential reaction of the air with the off gas component will protect the solid component from any significant oxidation while at the same time it will elevate the temperature in the reaction zone sufficiently to effect substantially complete decomposition of the material so that the recovered product is of very high carbon content. At the same time, a temperature gradient is established in the reaction zone which will allow some of the vapor component of the decomposition (i.e. heavier tars) to condense on the solid component at cooler regions for subsequent reintroduction into the high temperature regions so that the latent carbon content of these tars may also be recovered. The throughput or residence time of the material through the reaction zone and the amount of air introduced (to control the maximum reaction temperature as well as the temperature gradient) are controlled in related manner to recover more or less of the heavier tar residue.
- Georgia Tech Patents