Multi-zone reforming methods and apparatus for conversion of devolatilized biomass to syngas
The present invention provides improved methods and apparatus for producing syngas from any carbon-containing feed material. In one aspect, a multi-zone reformer system is provided. A first reaction zone can reduce the presence of refractory tars, while a second reaction zone in communication with the first reaction zone can steam-reform methane and other components from the first reaction zone, to generate high-quality syngas suitable for conversion to liquid fuels, such as ethanol. Other embodiments employ a plurality of reaction zones for added system functionality.
1. A method of producing syngas, said method comprising:
(a) combining a carbon-containing feedstock, including refractory tars, with steam, thereby generating an input stream;
(b) introducing said input stream into a first reaction zone under conditions effective to reduce the molecular weight of said refractory tars to an average molecular weight of 100 g/mol or less, thereby generating a first output stream including methane, wherein a temperature within said first reaction zone is at least 1700° F.;
(c) introducing said first output stream into a second reaction zone under conditions effective to steam reform at least some of said methane, thereby generating a second output stream including syngas, wherein a temperature within said second reaction zone is at least 1900° F.; and
(d) introducing said second output stream into a separation zone to remove at least some solid or liquid species present in said second output stream, wherein a temperature within said separation zone is less than 1600° F.
2. The method of claim 1 , wherein during step (b), said refractory tars are substantially destroyed and then, during step (c), at least partially converted to syngas.
3. The method of claim 1 , wherein BTEX species are present in said input stream, and wherein during step (b), the average molecular weight of at least a portion of said BTEX species is reduced.
4. The method of claim 1 , wherein BTEX species are present in said first output stream, and wherein during step (c), at least a portion of said BTEX species is converted into syngas.
5. The method of claim 1 , wherein said first reaction zone includes catalyzed reduction of the molecular weight of refractory tars.
6. The method of claim 1 , wherein said second reaction zone includes catalyzed steam reforming.
7. The method of claim 1 , wherein said separation zone is effective for cooling said second output stream.
8. The method of claim 1 , wherein said carbon-containing feedstock is obtained from a devolatilization unit.
9. The method of claim 1 , wherein said carbon-containing feedstock is devolatilized biomass.