Combustion of high solids liquid
09593849 ยท 2017-03-14
Assignee
Inventors
Cpc classification
F23G5/50
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/006
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G7/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/008
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23J3/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23B7/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G2900/50208
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/446
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F23G7/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23J3/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/50
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/44
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23G5/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A system for the combustion of high solids liquid to produce steam for the production of ethanol is disclosed. The system comprises a method for combusting high solids liquid. The method comprises supplying a stream of high solids liquid to a furnace; atomizing the stream of high solids liquid into the furnace; and distributing biomass fuel into the furnace. The stream of high solids liquid are combusted with the biomass fuel in the furnace.
Claims
1. A method for combusting a high solids liquid, comprising: supplying a stream of high solids liquid to a stoker grate boiler, wherein the stream of high solids liquid is atomized to form an atomized stream of high solids liquid; and distributing biomass into the stoker grate boiler; wherein the atomized stream of high solids liquid is combusted in suspension above the biomass in the stoker grate boiler.
2. The method of claim 1, wherein the atomizing comprises employing one or more nozzles.
3. The method of claim 2, wherein the atomizing further comprises using an atomization fluid.
4. The method of claim 3, wherein the atomization fluid comprises compressed air.
5. The method of claim 4, wherein the one or more nozzles are positioned in a horizontal configuration.
6. The method of claim 5, wherein the one or more nozzles create a spray pattern and the spray pattern is a fan type pattern.
7. The method of claim 6, wherein the one or more nozzles comprise at least one flat fan nozzle.
8. The method of claim 7, wherein the nozzle pressure is within the range of 30 to 100 pound-force per square inch gauge, inclusive.
9. The method of claim 8, further comprising selectively altering the rate at which the atomized high solids liquid is supplied.
10. The method of claim 4, wherein the one or more nozzles are positioned in a vertical configuration.
11. The method of claim 10, wherein the one or more nozzles create a spray pattern and the spray pattern is a fan type pattern.
12. The method of claim 11, wherein the one or more nozzles comprise at least one flat fan nozzle.
13. The method of claim 12, wherein the nozzle pressure is within the range of 30 to 100 pound-force per square inch gauge, inclusive.
14. The method of claim 13, further comprising selectively altering the rate at which the atomized high solids liquid is supplied.
15. The method of claim 3, wherein the atomization fluid comprises steam.
16. The method of claim 15, wherein the one or more nozzles are positioned in a horizontal configuration.
17. The method of claim 16, wherein the one or more nozzles create a spray pattern and the spray pattern is a fan type pattern.
18. The method of claim 17, wherein the one or more nozzles comprise at least one flat fan nozzle.
19. The method of claim 18, further comprising selectively altering the rate at which the atomized stream high solids liquid is supplied.
20. The method of claim 15, wherein the one or more nozzles are positioned in a vertical configuration.
21. The method of claim 20, wherein the one or more nozzles create a spray pattern and the spray pattern is a fan type pattern.
22. The method of claim 21, wherein the one or more nozzles comprise at least one flat fan nozzle.
23. The method of claim 22, further comprising selectively altering the rate at which the atomized stream of high solids liquid is supplied.
24. The method of claim 1, wherein the high solids liquid comprises syrup produced at an ethanol plant that produces ethanol from corn starch.
25. The method of claim 1, wherein the high solids liquid comprises syrup produced at a biorefinery that converts lignocellulosic biomass into ethanol.
26. The method of claim 1, wherein the biomass is selected from at least one member of the group consisting of corn cobs, corn stover, fiber from corn kernels, switchgrass, farm residue, agricultural residue, wood chips and other wood waste.
Description
DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE EMBODIMENTS
(19) Referring to
(20) According to an exemplary embodiment, the biorefinery 100 is configured to produce ethanol from biomass in the form of a lignocellulosic feedstock such as plant material from the corn plant (e.g. corn cobs and corn stover). Lignocellulosic feedstock such as lignocellulosic material from the corn plant comprises cellulose (from which C6 sugars such as glucose can be made available) and/or hemicellulose (from which C5 sugars such as xylose and arabinose can be made available).
(21) As shown in
(22) As shown in
(23) Referring to
(24) Referring to
(25) As shown in
(26) Referring to
(27) The liquid component (C5 stream) comprises water, dissolved sugars (such as xylose, arabinose and glucose) to be made available for fermentation into ethanol, acids and other soluble components recovered from the hemicellulose. The solids component (C6 stream) comprises water, acids and solids such as cellulose from which sugar, such as glucose, can be made available for fermentation into ethanol, and lignin.
(28) After pre-treatment and separation, the C5 stream and the C6 stream are processed separately; as shown, the C5 stream and the C6 stream may be processed separately (in separate treatment systems 510, 512) prior to co-fermentation (C5/C6 fermentation system 514 as shown in
(29) According to an exemplary embodiment shown in
(30) According to an exemplary embodiment shown in
(31) According to an aspect, syrup from an ethanol plant can be co-combusted in a stoker grate boiler to produce energy (e.g., steam energy, electrical energy) to power any suitable process, as shown in
(32) The high solids liquid can be a liquid with a high amount of combustible solids, wherein the combustible solids are small in size (e.g., in a powder form). The combustible solids can be syrup or whole stillage derived from an ethanol production process (cellulosic or starch based), as illustrated. However, the combustible solids can be derived from other processes, such as black liquor derived from a pulp mill, for example.
(33) As shown in
(34) According to an aspect, at least a portion of the syrup 722 (or other high solids liquid) can be mixed 724 with biomass 726 and combusted 728, such as in a solid fuel boiler to create energy 730, which can be in the form of steam. Thus, wood fuel (or other biomass fuel) is used as the primary medium for delivering syrup to the furnace.
(35) As produced in an ethanol plant, syrup and C6 solids comprise a high percentage of moisture, as shown in
(36)
(37) The wood and syrup mixture 808 is loaded into a metering bin 810 and fed into a furnace by air swept fuel distributors 812 and onto stoker grates 814 of the stoker grate boiler. The wood and syrup mixture 808 is fed into the furnace using a conventional wood burning technique and combusted.
(38) In accordance with some aspects, as shown in
(39) At least one nozzle 1002 is positioned in the lower portion of the membrane wall 1004 of the furnace 1000. Solid fuel combusted on the stoker grate is used to ignite syrup that is atomized through the at least one nozzle 1002 into the furnace, above the stoker grate. Wood fuel 1006 is directed into the furnace through openings 1008 by air swept fuel distributors 1010 to maintain combustion of wood fuel 1006 on the stoker grate 1012. Syrup is delivered to a manifold 1014 by a syrup supply line 1016. By atomizing syrup directly into the furnace at a selectable rate, the rate at which syrup is combusted can be selected to produce the best results possible. Since the syrup is atomized into the furnace, wood is not needed to carry the syrup into the furnace and the syrup combustion rate is not as dependent on the wood combustion rate. Further, wood in the metering bin is not placed in contact with syrup prior to the wood being delivered into the furnace, thus, the system for metering wood into the furnace does not come in contact with syrup, which mitigates plugging of the metering bin outlets, feed chutes, and air swept distributors and can provide an increased syrup combustion rate range.
(40) According to an aspect, the nozzles can each comprise a flat fan nozzle, commercially available, for example, Model NF from BETE Fog Nozzle, Inc. of Greenfield, Mass., attached to a stainless steel nipple that protrudes into the furnace. The nozzle can be connected to a manifold that allowed compressed air and syrup to be combined prior to entering the nozzle. The compressed air 1018 assists atomization of the syrup, which allows the atomized syrup 1020 to combust (in suspension) above the combusting wood fuel on the stoker grate.
(41) Sample operating conditions for a combustion system that combusts high solids liquid are shown in
(42) According to some aspects, the liquid fuel (e.g., syrup, whole stillage, or evaporated whole stillage) is atomized 1020 into the furnace 1000 through a space between the membrane wall tubes on the front 1102 of the furnace (as shown in
(43) As shown in
(44) According to some aspects, the spray pattern of the outside nozzles 1104, 1108 can be narrower than the spray pattern of the inside nozzle(s) 1106 to mitigate the chance that the outside nozzles 1104, 1108 will spray syrup onto the wall of the furnace 1000, where it might not combust completely. According to an embodiment, shown in
(45) In accordance with some aspects, heat can be utilized to atomize the syrup, wherein the syrup is heated at a pressure above atmospheric pressure. In order for the syrup to vaporize as it decreases in pressure by exiting the one or more nozzles, the temperature of the syrup could be below its high pressure vaporization temperature, but above approximately 212 degrees Fahrenheit. Under these conditions, heated syrup will atomize as it exists the nozzle and combust above the stoker grate.
(46) The syrup injection nozzle can be applied to various applications involving liquids having high solids content in a stoker grate boiler having a secondary flame source (e.g., biomass co-fired boiler).
(47) A series of examples were conducted according to an exemplary embodiment of the system (as shown in
Example 1
(48) The combustion system was used in Example 1 to test the effect on CO (Carbon Monoxide) and NOx (Nitrogen Oxides) emissions. Observations indicated that the combustion of syrup caused minimal increases in CO and NOx emissions compared to operation without combustion of syrup. However, the operation of the combustion system using water was observed to cause higher CO emission levels. It was observed that operating between 10 and 15 gpm yields the lowest combined CO and NOx emissions. The CO emissions were the lowest between 10 and 15 gpm of syrup combustion. The results are shown in
Example 2
(49) The combustion system was used in Example 2 to test the effect on CO (Carbon Monoxide) and NOx (Nitrogen Oxides) emissions when a urea system, which is a SNCR (Selective non-catalytic reduction (SNCR) for NOx control) system that controls NOx emissions by injecting urea into the furnace, was not operational. Thus, Example 2 provides NOx emission data without the NOx being affected by urea injection, as indicated in
Example 3
(50) The combustion system was used in Example 3 to test whether syrup (or a high solids liquid) decreased the observed CO emissions compared to both water injection and no injection. It was observed that the CO emission level was lower for both syrup flow rates than with no syrup and that water greatly increased the CO emissions. The test was conducted during a shutdown of the syrup combustion system. Prior to the shutdown, the CO averaged 49.47 ppm with a syrup flow rate of 11.69 gpm. During shutdown, water was flushed through the combustion system to clean rinse the system. Once the water entered the furnace, the CO emissions increased to an average of 1900.14 ppm at a water flow rate of 12.41 gpm. During the shutdown, when no water or syrup was flowing, the CO emissions averaged 412.29 ppm. After the combustion system was placed back into service, CO emissions averaged 73.59 ppm with a syrup flow rate of 7.34 gpm. The test indicated that syrup combustion reduces CO emissions. The results are shown in
(51) The embodiments as disclosed and described in the application (including the FIGS. and Examples) are intended to be illustrative and explanatory of the present invention. Modifications and variations of the disclosed embodiments, for example, of the apparatus and processes employed (or to be employed) as well as of the compositions and treatments used (or to be used), are possible; all such modifications and variations are intended to be within the scope of the present invention.
(52) The word exemplary is used to mean serving as an example, instance, or illustration. Any embodiment or design described as exemplary is not necessarily to be construed as preferred or advantageous over other embodiments or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Rather, use of the word exemplary is intended to present concepts in a concrete fashion, and the disclosed subject matter is not limited by such examples.
(53) The term or is intended to mean an inclusive or rather than an exclusive or. To the extent that the terms comprises, has, contains, and other similar words are used in either the detailed description or the claims, for the avoidance of doubt, such terms are intended to be inclusive in a manner similar to the term comprising as an open transition word without precluding any additional or other elements.