Renewable blended syngas from a plasma-based system

Abstract

A method and system for cost-effectively converting a feedstock using thermal plasma, or other styles of gassifiers, into an energy transfer system using a blended syngas. The feedstock is any organic material or fossil fuel to generate a syngas. The syngas is blended with any fuel of a higher thermal content (BTU) level, such as natural gas. The blended syngas high thermal content fuel can be used in any energy transfer device such as a boiler for simple cycle Rankine systems, an internal combustion engine generator, or a combined cycle turbine generator system. The quality of the high thermal content fuel is monitored using a thermal content monitoring feedback system and a quenching arrangement.

Claims

1. A method of extracting energy from a gassifier, the method comprising the steps of: delivering a feed stock product to the gassifier, wherein the feedstock comprises a municipal solid waste, wherein the feedstock is compressed to minimize the introduction of air, wherein the gassifier is inductively heated and wherein the gassifier is plasma assisted, and wherein the gassifier uses a pyrolysis method along with the inductively heated and plasma assisted process to create a fuel product; extracting the fuel product from the gassifier, the extracted fuel product having a first thermal content characteristic, wherein the extracted fuel product is extracted syngas, wherein the extracted fuel product is configured to comprise a consistent BTU content from a variable feedstock composition; injecting a portion of the extracted syngas in to the gassifier to chemically boost a heat of the gassifier; delivering the extracted fuel product to a fuel blending system; monitoring the thermal content of the extracted syngas and measuring the thermal content of the extracted syngas with the use of a thermal content measuring device; mixing a further fuel product comprising natural gas, wherein the further fuel product has a second thermal content characteristic with the extracted fuel product in the blending system, the second thermal content characteristic corresponding to a higher thermal content than the first thermal content characteristic, to form a blended fuel product of greater quality than the extracted fuel product issued by the gassifier, wherein the blended fuel product is a blended syngas product; and controlling a final thermal content of the blended syngas product in response to said step of measuring the thermal content of the extracted syngas, wherein the final thermal content is controlled to maintain a determined fuel quality with at least a minimum BTU.

2. The method of claim 1, wherein there is provided the further step of delivering the blended fuel product to a power transfer device.

3. The method of claim 2, wherein the power transfer device is a combined cycle electricity generation system.

4. The method of claim 3, wherein the combined cycle electricity generation system includes a gas turbine power generation system.

5. The method of claim 4, wherein the combined cycle electricity generation system includes a steam turbine power generation system.

6. The method of claim 5, wherein there is provided the further step of forming steam to power the steam turbine power generation system from thermal energy contained in an exhaust gas stream of the gas turbine power generation system.

7. The method of claim 1, wherein, prior to performing said step of delivering the feed stock product to the plasma assisted gassifier, there is provided the further step of passing the feed stock product through a pre-gassifier.

8. The method of claim 7, wherein there is provided the further step of delivering a reclaimed heat to the pre-gassifier.

9. The method of claim 1, wherein, prior to performing said step of delivering the extracted syngas to a fuel blending system, there is provided the further step of passing the feed stock product through a pre-gassifier.

10. The method of claim 1, wherein there is provided the further step of delivering a reclaimed heat to the pre-gassifier.

11. The method of claim 10, wherein prior to performing said step delivering the reclaimed heat to the pre-gassifier there is provided the further step of reclaiming heat from the extracted syngas.

12. The method of claim 11, wherein prior to performing said step of reclaiming heat from the extracted syngas there is provided the further step of subjecting the extracted syngas to a cleansing operation.

13. The method of claim 12, wherein said step of subjecting the extracted syngas to a cleansing operation comprises the step of subjecting the extracted syngas to a quenching operation.

14. The method of claim 13, wherein said step of subjecting the extracted syngas to a quenching operation comprises the further step of reducing a temperature of the extracted syngas.

15. The method of claim 1, where the thermal content measuring device is a flame ionization detector (FID).

16. The method of claim 1, where the thermal content measuring device is a calorimeter.

17. The method of claim 1, where the thermal content measuring device is a spectrometer.

18. A method of extracting energy from a plasma gassifier, the method comprising the steps of: delivering a feed stock product to the gassifier, wherein the feedstock comprises at least one of a renewable feedstock or a municipal solid waste, wherein the feedstock is compressed to minimize the introduction of air, extracting syngas from the plasma gassifier, wherein the plasma gassifier is inductively heated and wherein the gassifier is plasma assisted, and wherein the gassifier uses a pyrolysis method along with the inductively heated and plasma assisted process to create the extracted syngas, the extracted syngas having a first thermal content characteristic; injecting a portion of the extracted syngas in to the gassifier to chemically boost a heat of the gassifier delivering the extracted syngas to a fuel blending system; monitoring the thermal content of the extracted syngas and measuring the thermal content of the extracted syngas with the use of a thermal content measuring device; mixing a further fuel product comprising natural gas, wherein the further fuel product has a second thermal content characteristic with the extracted syngas in the blending system, the second thermal content characteristic corresponding to a higher thermal content than the first thermal content characteristic, to form a blended syngas fuel product of greater quality than the extracted syngas; and controlling a final thermal content of the blended syngas fuel product in response to said step of measuring the thermal content of the extracted syngas, wherein the final thermal content is controlled to maintain a determined fuel quality with at least a minimum BTU.

19. The method of claim 1, wherein the feed stock product comprises a solid waste or an inorganic mix.

20. The method of claim 18, wherein the syngas is extracted from a feed stock product and wherein the feed stock product comprises a solid waste or an inorganic mix.

21. The method of claim 1, further comprising delivering a lime additive to the gassifier, wherein the lime additive is configured to control emissions and improve a quality of an output slag.

22. The method of claim 18, further comprising delivering a lime additive to the gassifier, wherein the lime additive is configured to control emissions and improve a quality of an output slag.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Comprehension of the invention is facilitated by reading the following detailed description, in conjunction with the annexed drawing, in which:

(2) FIG. 1 is a simplified schematic representation of a process and system for generating blended syngas from a renewable energy source constructed in accordance with the principles of the invention; and

(3) FIG. 2 is a simplified schematic representation of a combined cycle generator of electrical power.

DETAILED DESCRIPTION

(4) FIG. 1 is a simplified schematic representation of a process and system 100 for generating blended syngas from an energy source constructed in accordance with the principles of the invention. As shown in this figure, municipal solid waste or other feedstock, designated as MSW 1, is delivered in this specific illustrative embodiment of the invention to system 100 a crane 2. The feedstock can be any organic material, inorganic mix, or fossil fuel. Crane 2 transfers MSW 1 to a shredder 3. The shredded feedstock (not shown) is then delivered to a pre-gassifier chamber 4. It is to be understood that any other form of gassifier can be employed in the practice of the invention. In this embodiment pre-gassifier 4 has been integrated to reduce the work that otherwise would be done by plasma torch 21.

(5) The feed system, which includes shredder 3, compresses the incoming feedstock MSW 1 so as to minimize the introduction of air. Plasma chamber 9, or other conventional gassifier is, in this specific illustrative embodiment of the invention, advantageously operated in a pyrolysis mode or in air and/or oxygen combustion boosted modes of operation. Additives such as lime 5 are added, in this embodiment, to the gassifier to control emissions and improve the quality of an output slag 24.

(6) Methods of chemically boosting heat such as with the use of liquid or gaseous fuels and an oxidant injected into port 6 can be used in the practice of the invention. Recirculated syngas, natural gas, or any of several other fuels (not shown), are combined with air or oxygen at an approximate stoichiometric ratio, constitute practicable embodiments of the invention.

(7) The quality of the syngas can be improved by the injection of steam at steam input line 25 into plasma chamber 9.

(8) A syngas product is supplied via a syngas line 10 to a quench system 23 to reduce particulate and other emissions and to reduce the temperature of the syngas to a level that is acceptable to a final syngas purification system 13. Persons skilled in the art will realize that conventional sour water cleanup systems for the quench system have purposely been omitted from this figure for the sake of clarity.

(9) The use of final heat recovery system 14 is optional. In some embodiments, combined cycle turbines are capable of consuming high temperature fuel, which increases the Wobbe Index and increases system efficiency. In embodiments where final heat recovery system 14 is not included, pre-gassifier 4 can be heated from line 11, which is shown directed to the quench system. The quench system in some embodiments utilizes a cooling tower (not shown) that has been omitted from the figure for the sake of clarity.

(10) Compressor 15 draws a slight vacuum on the system and directs the syngas to three way valve 26 and calorimeter 16. Other fuel quality measuring devices can be employed in the practice of the invention, such as a flame ionization detector (FID) (not shown) or a spectrometer (not shown). The output of calorimeter 16 is used as an input to a control loop that continuously adjusts the position and ratio of mixing in control valve 27. As stated, the syngas in line 17 is directed to a blending valve 27 that mixes natural gas 18, or any other fuel (not shown) such as ethane, propane, butane, pentane, etc. The mixing valve can, in some embodiments, be incorporated in a closed loop (not shown) that maintains a determined fuel quality that is issued at a fuel delivery line 19. Modern combined cycle generators can consume virtually any fuel that contains over 600 BTU/cu ft, and preferably 700 to 800 BTU/cu ft. In case of an emergency, such as a situation where the power generating system must quickly be taken off line, syngas in line 28 is oxidized in emergency oxidizer 20.

(11) FIG. 2 is a simplified schematic representation of a combined cycle generator of electrical power. As shown in this figure, fuel is received at fuel delivery line 19, which continues from system 100 in FIG. 1. The fuel delivery line delivers the fuel to a combustion chamber 40 that supplies the resulting combusted gasses to a gas turbine 42. The exhaust of the gas turbine is issued as exhaust gas 44 via an output line 46. The rotational displacement of gas turbine 42 is coupled by a shaft (not specifically designated) to a gas turbine generator 50 that issues electricity 52.

(12) As a secondary power generation system, there is provided a steam turbine 60 that operates in the context of a closed loop, as follows: A liquid (not specifically designated) that includes water is present in a condenser 62. The liquid is conducted along a line 64 to a heat recover steam generator 66 that is disposed in the exhaust path (output line 46) of gas turbine 42. The liquid in line 64 is heated by the exhaust of the gas turbine, and is converted to steam (not specifically designated) in a steam line 68. The steam line supplies the steam to steam turbine 60, the spent steam output of which is delivered to condenser 62, whereby the spent steam is re-liquified and the cycle is thus repeated continuously.

(13) Although the invention has been described in terms of specific embodiments and applications, persons skilled in the art can, in light of this teaching, generate additional embodiments without exceeding the scope or departing from the spirit of the invention described and claimed herein. Accordingly, it is to be understood that the drawing and description in this disclosure are proffered to facilitate comprehension of the invention, and should not be construed to limit the scope thereof.