System integration of a steam reformer and gas turbine
View Patent ↗A novel process and apparatus for power generation from biomass and other carbonaceous feedstocks are provided. The process integrates a pulse combustor steam reformer with a gas turbine to generate electricity such that (i) efficiency is higher than those of conventional and current advanced power systems, (ii) emissions are lower than those proposed in the new environmental regulations, and (iii) performance is comparable to that of combined cycle, even though a bottoming cycle is not included here. The pulse combustor steam reformer generates a hydrogen-rich, medium-Btu fuel gas that is fired in a gas turbine to generate electricity. The apparatus may be configured to produce only power or combined heat and power.
1. A process for producing electricity from carbonaceous materials comprising the steps of:
providing a fluidized bed containing a particulate material and a fluidizing medium, said fluidizing medium comprising steam;
combusting a fuel source in a combustion device to form a combustion stream, said combustion stream indirectly heating said fluidized bed;
feeding a carbonaceous material to said fluidized bed, said fluidized bed being at a temperature sufficient for said carbonaceous material to endothermically react with said steam to form a product gas stream;
feeding said product gas stream to a gas turbine, said gas turbine combusting said product gas stream in order to rotate a turbine and generate electricity, said gas turbine producing a flue gas stream;
combining an air stream with the product gas stream prior to combusting the product gas stream in the gas turbine, the air stream being preheated by the combustion stream exiting the combustion device;
preheating at least a portion of the flue gas stream exiting the gas turbine by the combustion stream exiting the combustion device; and
feeding at least a portion of said flue gas stream to said combustion device for combustion with said fuel source.
2. A process as defined in claim 1 , wherein said carbonaceous material comprises a material selected from the group consisting of coal, pulp and paper waste, wood products, municipal waste, sewage, food waste, plant matter, animal waste, industrial waste, biomass and mixtures thereof.
3. A process as defined in claim 1 , wherein said carbonaceous material comprises rice straw and wherein the process further comprises the step of collecting silica as a byproduct from said fluidized bed.
4. A process as defined in claim 1 , wherein said carbonaceous material comprises animal waste and wherein a material selected from the group consisting of phosphorous, nitrogen and potassium are generated and collected during the process.
5. A process as defined in claim 1 , wherein said fluidized bed is maintained at a temperature of from about 900 degrees F. to about 1800 degrees F.
6. A process as defined in claim 1 , wherein said steam to said carbonaceous material have a weight ratio of from about 0.75:1 to about 3:1.
7. A process as defined in claim 1 , wherein said combustion device is a pulse combustion device.
8. A process as defined in claim 1 , wherein prior to said gas turbine, said product gas stream is fed to a heat exchanger for heating steam fed to said fluidized bed.
9. A process as defined in claim 1 , wherein after exiting said fluidized bed, said combustion stream is fed to a steam generator for generating steam fed to said fluidized bed.
10. A process as defined in claim 1 , wherein said product gas stream is fed to a compressor prior to being combusted in said gas turbine, said compressor compressing said product gas stream to a pressure greater than the inlet pressure of said gas turbine.
11. A process as defined in claim 10 , wherein said product gas stream is mixed with the preheated air stream prior to being combusted in said gas turbine.
12. A process as defined in claim 1 , wherein after exiting said fluidized bed, said combustion stream is fed to a steam generator for generating steam fed to said gas turbine.
13. A process as defined in claim 1 , wherein the air stream is fed to a compressor and compressed prior to being preheated by the combustion stream exiting the combustion device.