Systems and Methods for Isolating Substantially Pure Carbon Dioxide from Flue Gas
20230175686 · 2023-06-08
Inventors
Cpc classification
F23J2900/15061
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02E20/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F23N5/006
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23J15/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23J15/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02C20/40
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F22D1/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02E20/32
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F23C9/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23J2215/50
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23J2219/60
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F23C9/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F22D1/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F23L7/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A method for isolating substantially pure carbon dioxide from flue gas is provided. The method can include combusting carbon based fuel to form flue gas; cooling the flue gas to provide substantially dry flue gas; removing N.sub.2 from the dry flue gas to provide substantially N.sub.2 free flue gas CO.sub.2; and liquifying the substantially N.sub.2 free flue gas CO.sub.2 to form substantially pure carbon dioxide.
Claims
1. A method for isolating substantially pure carbon dioxide from flue gas, the method comprising: combusting carbon based fuel to form flue gas; cooling the flue gas to provide substantially dry flue gas; removing N.sub.2 from the dry flue gas to provide substantially N.sub.2 free flue gas CO.sub.2; and liquifying the substantially N.sub.2 free flue gas CO.sub.2 to form substantially pure carbon dioxide.
2. The method of claim 1 wherein: the carbon based fuel is natural gas; the cooling the flue gas comprises reducing the water content of the flue gas to less than 3%; the removing the N.sub.2 to form the substantially N.sub.2 free flue gas CO.sub.2 is performed with a pressure swing adsorption assembly; and the liquifying comprises compressing and cooling the substantially N.sub.2 free flue gas CO.sub.2 to provide the substantially pure carbon dioxide.
3. The method of claim 2 wherein: the reducing the water content of the flue gas to less than 3% comprises a combination of step wise diversion and/or temperature reduction.
4. The method of claim 3 wherein the step wise temperature reduction comprises using one or more economizers.
5. The method of claim 4 wherein the economizers are in series.
6. The method of claim 3 wherein the step wise temperature reduction comprises condensation to reduce the water content.
7. The method of claim 3 further comprising pressurizing the <3% flue gas and/or further condensing the <3% flue gas.
8. The method of claim 7 further comprising drying the pressurized <3% flue gas.
9. The method of claim 2 wherein the compressing and cooling to provide the substantially pure CO.sub.2 is performed stepwise.
10. The method of claim 9 wherein the compressing and cooling is performed in series.
11. The method of claim 2 further comprising drying the flue gas to reduce the water content of the flue gas to <10 ppm.
12. The method of claim 2 further comprising reducing the water content from <3% to <10 ppm using one or more of pressurization, heat exchange, and/or drying.
13. The method of claim 2 wherein the substantially N.sub.2 free flue gas CO.sub.2 comprises >95% CO.sub.2.
Description
DRAWINGS
[0011] Embodiments of the disclosure are described below with reference to the following accompanying drawings.
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DESCRIPTION
[0030] This disclosure is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
[0031] The present disclosure will be described with reference to
[0032] In accordance with example implementations, at least about 600 standard cubic feet per minute of building flue gas can be diverted to the flue gas process stream where CO.sub.2 is separated and purified in component 14 of system 10. This separation/purification component can be an adsorption purification system, operated under conditions of Pressure Swing (PSA), Temperature Swing (TSA), or Electrical Swing (ESA), or any combination thereof. In accordance with example implementations, it can be a Pressure Swing Adsorption system that is a multicomponent adsorption system that includes multiple vessels containing layered solid phase adsorbent materials coupled and/or configured to work in concert to provide greater than 85% CO.sub.2 recovery. These multicomponent adsorption systems can remove carbon dioxide from an essentially “dry” flue gas stream to a purity of greater than 95% in most cases, and in other cases, at least 99%. This purified carbon dioxide gas can then be liquified with successive cooling and compression steps to effect phase change to form liquid carbon dioxide in liquefaction component 16, and then providing that liquified carbon dioxide to a storage component 18 for scheduled removal as desirable. In accordance with example implementations, this liquified carbon dioxide can be transferred away in transfer component 19, and the transfer can be provided to another source such as a storage facility which can distribute the carbon dioxide for use in applications such as concrete curing, waste water treatment, other carbon dioxide sequestration methods, recycled for fire suppression systems, industrial specialty gas, consumed in production of hybrid fuels and organic intermediate chemicals, or for beverage carbonation, as a few examples.
[0033] Referring next to
[0034] Referring next to
[0035] Referring next to
[0036] In accordance with example implementations, control 66 can utilize sensor 43 to monitor the amount of free oxygen in the combustion burner and maintain the amount of free oxygen to about 3%. About 3% free oxygen can include free oxygen from 3 to 7%. In accordance with example implementations, combustion can generate flue gas 44. The composition of flue gas 44 can be controlled to include at least about 10% carbon dioxide. About 10% carbon dioxide can include carbon dioxide from 9 to 12% of the flue gas from combustion of natural gas. System 10 can be utilized to combust fuels other than natural gas which may dictate other optimal CO.sub.2 flue gas concentrations. Accordingly, system 10 can be configured to utilize multiple fuels.
[0037] The systems and/or methods of the disclosure can include separating the carbon dioxide from the flue gas, liquefying the carbon dioxide after separating the carbon dioxide from the flue gas, liquefying the separated carbon dioxide after separating the carbon dioxide from the flue gas, storing the carbon dioxide after liquefying the carbon dioxide, and/or transporting the carbon dioxide after storing the carbon dioxide.
[0038] Referring to both
[0039] In accordance with at least one aspect of the present disclosure, real time control of the combustion source, or boiler, can achieve higher efficiency to reduce consumption of natural gas or fuel, for example, while increasing the concentration of carbon dioxide in the flue gas. This may be considered counter intuitive to increase the concentration of carbon dioxide in the flue gas when the systems and/or methods of the present disclosure are being utilized to reduce carbon emissions from a building. However, increasing carbon dioxide concentration can provide the benefit of decreasing fuel consumption by reducing heat loss through the exhaust. Adjusting combustion to control free oxygen to 3% can give a higher efficiency burn. In accordance with example implementations, through combustion control, it is desirable to approach the 12% concentration value of CO.sub.2, when burning natural gas, and achieve at least about 10% carbon dioxide concentration of the flue gas. This is at least one feature of the disclosed building emission processing systems and/or methods and can be utilized as one of the initial steps in carbon capture.
[0040] Within the building, boiler operation can be dictated by responding to the need for hot water or steam by controlling the combustion burner to various predetermined firing rates; 1) an off condition, 2) a low fire rate, and/or 3) a high fire rate. These rates may have been established on older boilers through calibrated mechanical linkages, for example. Recognizing that cyclic boiler operation will vary widely from hour to hour, day to day, and season to season, it is desired to establish automatic control of the flame rate continuously across the entire boiler load range, while also controlling free oxygen as discussed above. The systems and/or methods of the present disclosure can be configured to reduce on-off cycles by extending boiler run time at a reduced flame rate, increasing the life on the boilers, and providing a more continuous flow of flue gas to the separation, liquefaction, storage and/or transport systems and/or methods of present disclosure.
[0041] Accordingly, the boiler and system controls (for example
[0042] Referring next to
[0043] Additionally, the economizer can be configured for condensing. Accordingly, a conduit, set of conduits, or coils 54 can be configured to convey potable or industrial process water that is received from a utility for example.
[0044] This water can have the temperature close to that of ground water as it is conveyed through typically underground pipes. Accordingly, the water has a substantially different temperature than the flue gas, even after being partially cooled in the non-condensing economizer. The providing of the flue gas to these conduits can remove water from the flue gas thus creating a water condensate effluent 53. This water proceeding through the conduits can be heated and provided to a water heating system 58 (
[0045] Accordingly, where an economizer is down process stream from a diverter, a blower may precede the economizer. In accordance with example implementations, the flue gas is at least about 10% carbon dioxide and/or at least about 3% free oxygen prior to entering the first economizer. The systems and/or methods of the present disclosure can utilize economizers configured as shown in
[0046] It has been determined that flue gas from the boiler may have a water content of approximately 18%, and a temperature ranging up to 350° F. Prior to separation of CO.sub.2, this water can be substantially removed from the flue gas. This involves dropping the flue gas temperature below dewpoint and allowing water to condense out as a liquid. As the water content of the flue gas lowers, so does the dewpoint, requiring yet additional cooling to continue removing the water. This cooling can result in flue gas condensates.
[0047] Flue gas condensates tend to be slightly acidic (at pH<=5) which is a condition that can damage some building plenums due to construction materials (such as carbon steel) which are not acid resistant. In these cases, gas must be removed from the plenum and condensed in external heat exchangers having acid resistant stainless steel components. Additionally, depending on condenser design, some amount of micro-liquid particles may remain in the gas stream. These micro-liquid particles can be referred to as acid aerosols which can be present at ppm levels. The present disclosure contemplates the removal of acid aerosols. These systems and/or methods include wet wall heat exchangers, impingers with inert reticulated carbon foam, and precipitators for example.
[0048] In accordance with the above, the non-condensing economizer can operate above dew point temperature, preventing any liquid condensate from forming. Without condensation, this economizer can be compatible with most plenum construction materials.
[0049] As described above, a condensing economizer can be provided downstream of the diverter (
[0050] Referring next to
[0051] Heat exchanger 70 can be a tube and shell configuration, cooled by an external water/glycol loop provided from a chiller and/or water from the building cooling tower for example. As shown, the water removed from the system at heat exchanger 70 can be slightly acidic, and it is anticipated that the water can be neutralized before proceeding to a Publicly Owned Treatment Works (POTW) or through a sewer system. Additionally, some water will remain in the process stream as small micro droplets, mist, or acidic aerosols which will be minimized or removed with special heat exchanger designs, impingement devices, or possibly a precipitator.
[0052] After a preponderance of water has been removed, and acidic aerosols mitigated, the cooled flue gas 72 can continue on to a compressor to increase pressure of the flue gas to an optimum level of approximately 100 psig, or lower, as dictated by the PSA system specification.
[0053] Referring next to
[0054] Referring to
[0055] Referring again to
[0056] From the dryer, the flue gas 79, containing less than 10 ppm water, can proceed to pressure swing adsorption (PSA) assembly 80. This pressure swing adsorption assembly can provide greater than 85% CO.sub.2 recovery, at greater than 95% purity, at 1 psig, and at 100° C. Maximum CO.sub.2 output flow at this point can be approximately 40 SCFM. The remainder of the flue gas, mostly nitrogen may continue under pressure, and/or be split with a portion returning to dryer 78. Another portion of the nitrogen can proceed to a turbine expander 82/generator 93 which can provide electrical energy 94 and a cold output gas, at near ambient pressure. Additionally, a control valve 84 equipped with a silencer can be operationally aligned in parallel with expander 82/generator 93.
[0057] Accordingly, methods for separating carbon dioxide from flue gas generated from a combustion boiler within a building are provided that can include removing at least some of the nitrogen from the flue gas to produce greater than about 95% carbon dioxide 78 using a pressure swing adsorption assembly 80. Nitrogen removed from the flue gas can be used to remove water from the flue gas before providing the flue gas to the pressure swing adsorption assembly, in dryer 78, for example. Alternatively, or additionally, at least some of the nitrogen removed from the flue gas can be provided to a gas expander/generator. Alternatively, or additionally one part of the nitrogen from the PSA can be provided to a control valve equipped with a silencer and providing another part to the expander/generator. In accordance with example implementations, the systems and/or methods of the present disclosure can include separating the nitrogen into parts and providing one part to the dryer and another part to the expander/generator. In one example implementation, the one part is about a third of the nitrogen from the pressure swing adsorption assembly.
[0058] Systems and/or methods are also provided for cooling carbon dioxide separated from flue gas generated from a combustion boiler within a building using the nitrogen exhaust of a PSA. The systems and/or methods can include separating nitrogen from flue gas using pressure swing adsorption assembly 80, and expanding the nitrogen through a turbine within the presence of a heat exchanger 92 to cool fluid within heat exchanger 92; and transferring that cooled fluid to another heat exchanger 100 operably aligned with the carbon dioxide product of the pressure swing adsorption assembly to cool the carbon dioxide product 78. The turbine can be part of a generator 93, for example, or may be provided to cool exchanger 92.
[0059] Typically, the nitrogen gas exiting the PSA can be at least 85 psig. with a flow exceeding 65% of the rated system flow. In accordance with example implementations, the nitrogen may be processed and saved as a marketable product. With regard to the electricity generation, grid compatible power conversion will be needed. The turbine generator will have a 500 Hz output which is not compatible with a 60 Hz grid. Therefore, it is envisioned that appropriate power conversion will be specified. This can be rectification followed by DC to AC multi phase inverter with proper safety features in case of a building power outage. After use in the turbine generator, and in the CO.sub.2 heat exchanger, the nitrogen waste gas can proceed back to the exhaust stack or plenum.
[0060] Referring next to
[0061] Referring next to
[0062] Vapor 116 at the top of vessel 113 is managed by a refrigeration system 122 which cools vapor 116, which condenses back to liquid 114, which returns back into vessel 113. In accordance with example configurations, system 122 can be configured as a loop in fluid communication with vessel 113 wherein vapor CO.sub.2 116 enters system 122 and returns to vessel 113 as a liquid CO.sub.2 114. In at least one configuration, system 122 is configured as a low temperature condenser equipped with an evaporator.
[0063] In the event of building power loss, the superior insulation of a vacuum jacketed tank, for example, may maintain liquid CO.sub.2 for at least 30 days. In accordance with example implementations, the building itself may be able to tap into vessel 113 for a supply of CO.sub.2 to extinguish fires; for example, fires related to electronic components that require CO.sub.2 extinguishing methods.
[0064] With reference to
[0065] Referring next to
[0066] Referring to
[0067] As shown in
[0068] Accordingly, flue gas can be cooled for water knockout, and heat generating electrical components such as compressors, blowers, pumps, and fans can be cooled as well.
[0069] In accordance with example implementations, the systems and/or methods of the present disclosure can include an energy storage system that can be configured to include a power conversion component and/or a battery or battery bank component. As one example, energy can be generated via turbine expansion of the nitrogen and this energy can be converted and stored within the building. The energy may be converted and provided directly to system components, for example compressors, and/or provided to the system components after storage, thus lowering building energy demand. Additionally, the energy may be provided to the power grid associated with the building itself.
[0070] In accordance with example implementations, using the MASTER PLC, energy generated with the system can be utilized during “peak demand” times (when, for example electricity rates are higher) and/or when the building is utilizing a “peak” amount of power. During these times, the MASTER PLC is monitoring building demand and then modify the system parameters to efficiently use energy storage and/or change carbon dioxide separation, liquefaction, storage, and/or transport to lower energy consumption during “peak demand” thus providing energy cost savings.
[0071] Example implementations of the systems and/or methods of the present disclosure can provide not only a carbon capture system but also an improvement in overall building energy efficiency (both thermal and electrical) while lessening CO.sub.2 emissions. Example implementations can include lowering carbon fuel consumption through optimizing boiler combustion, providing warmer boiler feed water thus requiring less energy to heat the boiler feed water, warming potable or process water thus requiring less energy to the heat the potable or process water, generating electrical energy and using same to power system components, and/or using building cooling towers to reduce building thermal load, etc., which individually and/or collectively can be part of systems that dramatically improve building efficiency.
[0072] In compliance with the statute, embodiments of the invention have been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the entire invention is not limited to the specific features and/or embodiments shown and/or described, since the disclosed embodiments comprise forms of putting the invention into effect.