Biomass high efficiency hydrothermal reformer
View Patent ↗A method of producing synthesis gas by mixing a carbonaceous feed comprising at least one carbonaceous material with superheated steam to produce a reformer feedstock and reforming the reformer feedstock to produce a first synthesis gas comprising hydrogen and carbon monoxide by introducing the reformer feedstock into a plurality of coiled tubes within a reformer at a reformer temperature and a reformer pressure at which at least a portion of the reformer feedstock is converted to synthesis gas.
1. A method of producing synthesis gas, the method comprising:
mixing a carbonaceous feed comprising at least one carbonaceous material with superheated steam to produce a reformer feedstock;
reforming the reformer feedstock to produce a synthesis gas comprising hydrogen and carbon monoxide by distributing the reformer feedstock into a plurality of coiled tubes within a reformer at a reformer temperature and a reformer pressure at which at least a portion of the reformer feedstock is converted to synthesis gas;
catalytically converting at least a portion of the synthesis gas into synthesis gas conversion product comprising liquid hydrocarbons; and
recycling, from the catalytic conversion, a spent catalyst stream comprising spent catalyst and associated synthesis gas conversion product separated therewith, a tailgas, or both to the reformer.
2. The method of claim 1 wherein the reformer feedstock comprises less than about 1 lb of steam per pound of carbonaceous material.
3. The method of claim 1 wherein the carbonaceous feed comprises primarily biomass.
4. The method of claim 3 comprising recycling the spent catalyst stream to the reformer.
5. The method of claim 3 wherein each of the plurality of coiled tubes has a height in the range of from about 40 feet (12.2 m) to about 100 feet (30.5 m), and a coil length that is at least four times the vertical height.
6. The method of claim 5 wherein each of the plurality of coiled tubes has a coil length in the range of from about 400 feet (121.9 m) to about 1000 feet (304.8 m).
7. The method of claim 3 further comprising maintaining the reformer temperature via combustion of a fuel.
8. The method of claim 7 wherein the fuel comprises tailgas recycled from the catalytic conversion.
9. The method of claim 7 wherein combustion of the fuel produces a flue gas, and wherein the method further comprises producing superheated steam utilizing, at least in part, the heat from the flue gas produced during reforming.
10. The method of claim 9 further comprising utilizing at least a portion of the superheated steam produced via heat transfer with the flue gas to produce additional reformer feedstock.
11. The method of claim 3 further comprising maintaining a reformer temperature of at least 1700° F. (927° C.).
12. The method of claim 3 further comprising maintaining a reformer pressure of at least 45 psig.
13. The method of claim 1 further comprising preparing the carbonaceous feed by subjecting at least one carbonaceous material to comminution, drying or both.
14. The method of claim 13 wherein preparing the carbonaceous feed comprises grinding and sizing at least one carbonaceous material to provide at least one carbonaceous material having an average particle size of less than about 3/16 th inch (0.47 cm).
15. The method of claim 13 wherein preparing the carbonaceous feed comprises drying at least one carbonaceous material to provide at least one carbonaceous material having a moisture content of less than about 20 weight percent.
16. The method of claim 13 wherein the carbonaceous feed further comprises the spent catalyst stream.
17. The method of claim 16 wherein the synthesis gas conversion product comprises primarily liquid Fischer-Tropsch hydrocarbons.
18. The method of claim 1 wherein reforming is performed at a reformer temperature above 1700° F. (927° C.).
19. The method of claim 18 wherein reforming is performed at a reformer temperature in the range of from about 1700° F. (927° C.) to about 2200° F. (1204° C.).
20. The method of claim 1 wherein the average residence time of the reformer feedstock within the reformer is in the range of from about 0.3 s to about 3 s.