Biogas upgrading technology for power generation
A method for powering an internal combustion engine or other device powered by combustion includes a step of feeding a first stream of biogas to a catalytic reforming reactor in which the first stream contacts oxygen to form a first product stream comprising synthesis gas. The first product stream is combined with a second stream of biogas to form a second product stream. The second product stream is provided to a device powered by combustion. A system implementing the method is also provided.
1. A method comprising:
combining a first stream of biogas with an oxygen-containing stream to form a combined stream, the first stream of biogas including methane;
feeding the combined stream to a catalytic reforming reactor in which biogas reacts with an oxygen-containing compound to form a first product stream comprising synthesis gas;
exchanging heat between the first product stream and the oxygen-containing stream to heat the oxygen-containing stream;
combining the first product stream with a second stream of biogas to form a second product stream, the second stream of biogas including methane;
providing the second product stream to a device powered by combustion; and
exchanging heat between flue gas from the device powered by combustion and the first stream of biogas to heat the first stream of biogas.
2. The method of claim 1 wherein the oxygen-containing compound is steam.
3. The method of claim 2 wherein a weight ratio of steam to methane is from about 1 to 5.
4. The method of claim 1 wherein the device powered by combustion is operated under lean-burn conditions.
5. The method of claim 4 wherein the device powered by combustion is operated under lean-burn conditions with an air-to-fuel equivalence ratio greater than 1.
6. The method of claim 1 wherein the device powered by combustion is an electric generator.
7. The method of claim 1 wherein heat is transferred from the device powered by combustion to the catalytic reforming reactor.
8. The method of claim 1 wherein the oxygen-containing compound is carbon monoxide.
9. The method of claim 1 wherein the combined stream is heated to a temperature from about 550° C. to about 850° C. before being fed to the catalytic reforming reactor.
10. The method of claim 1 wherein the catalytic reforming reactor contains a catalyst that includes nickel.
11. The method of claim 1 wherein the catalytic reforming reactor contains a catalyst that includes a noble metal.
12. The method of claim 1 wherein the catalytic reforming reactor contains a catalyst that includes platinum, ruthenium or palladium.
13. The method of claim 1 wherein the first stream of biogas includes flue gas from a rich-burn engine.