Catalytic conversion of carbonaceous feedstock material into a biochar product
Systems, methods and apparatus for the thermal conversion of carbonaceous feedstock material into biochar. The carbonaceous feedstock material may be harvested, preprocessed and pyrolyzed. An amount of carbonaceous feedstock material is received. An amount of a catalyst is applied to the carbonaceous feedstock material. The carbonaceous feedstock material and the applied catalyst is heated in an anaerobic environment to a temperature of at least 300 C. The biochar material is then generated.
1. A method of converting a carbonaceous feedstock material into a solid carbon product, the method comprising:
receiving an amount of a carbonaceous feedstock material;
applying an amount of a liquid catalyst solution to the carbonaceous feedstock material, the liquid catalyst solution comprising a transition metal salt and water, the transition metal salt selected from the group consisting of Fe(NO 3 ) 3 , Fe(NO 3 ) 2 and FeCl 3 ;
soaking the feedstock material in the liquid catalyst solution for a period of time allowing the feedstock material to absorb iron ions into the feedstock material, wherein the mass of transition metal in the liquid catalyst solution is less than a mass of the feedstock material;
heating the carbonaceous feedstock material and the applied liquid catalyst solution in an anaerobic environment to a temperature of at least 300 C; and
generating a graphitic biochar material, wherein the graphitic biochar material comprises an amount of added iron (Fe) from the transition metal salt;
applying an amount of acid to the graphitic biochar material; and
recovering an amount of the catalyst from the graphitic biochar material, wherein the catalyst FeCl 3 is recovered where the applied amount of acid is hydrochloric acid, and wherein the catalyst Fe(NO 3 ) 3 and/or Fe(NO 3 ) 2 is recovered where the applied acid is nitric acid.
2. The method of claim 1 wherein the Fe(NO 3 ) 3 biases carbon structures of the carbonaceous feedstock material from an sp3 structures to graphitic sp2 structures.
3. The method of claim 2 , wherein the generated graphitic biochar material has carbon bond structure with a ratio of at least 4:1 sp2 structures to sp3 structures.
4. The method of claim 1 , wherein the anaerobic environment comprises a positive pressure reactor.
5. The method of claim 1 , wherein the carbonaceous feedstock material is received onto a conveyor and the catalyst is applied to the carbonaceous feedstock material while moving on the conveyor.
6. The method of claim 1 , further comprising:
receiving into a container the carbonaceous feedstock material; and
soaking the carbonaceous feedstock material with the liquid catalyst solution such that the carbonaceous feedstock material absorbs iron at a 1:n ratio for n units of feedstock material to every one unit of iron, wherein n is a value greater than 1.
7. The method of claim 1 , wherein the carbonaceous feedstock material is heated to over 900 C.
8. The method of claim 1 , recovering an amount of the catalyst from the generated graphitic biochar material by washing the generated biochar material with water.
9. The method of claim 1 , further comprising:
cooling the heated graphitic biochar material, and then applying the amount of acid; and
forming turbostratic graphic carbon in the cooled graphitic biochar material;
recovering an amount of Fe(NO 3 ) 3 from the turbostratic graphitic carbon in the cooled graphitic biochar material by the applying nitric acid.
10. The method of claim 1 , further comprising:
cooling the heated graphitic biochar material, and then applying the amount of acid; and
forming turbostratic graphic carbon in the cooled graphitic biochar material;
recovering an amount of FeCl 3 from the turbostratic graphitic carbon in the cooled graphitic biochar material by applying the hydrochloric acid.
11. The method of claim 1 , wherein the carbonaceous feedstock material is any one of wood, corn stover, rice straw or nut hulls.