Patent ID: 7909896

Claim:
A method for preparing carbon-derived char comprising the steps of: (a) providing a carbonaceous precursor material; (b) lowering the agglomeration value of the carbonaceous precursor material through the addition of inert organic matter; (c) raising the percentage of volatiles in the carbonaceous precursor material to prevent agglomeration and caking; (d) roasting the carbonaceous precursor material for between about 2 hours and about 4 hours in a multi-hearth roaster including a plurality of decks constructed of non-corrosive metal with high-heat transfer characteristics, with the ability to move a thin layer of material with rotating arms equipped with plow-shaped protrusions, in a substantially anaerobic environment at a roasting temperature between about 300 and 700 degrees Celsius; (e) cooling the resultant solid char; (f) after step (d) and before step (e) extracting tar gases; (g) before step (e) filtering the tar gases; and (h) before step (e) washing the tar gases.