Patent Application
20110132577
The present invention relates to the production of fuels and, in particular to systems for using waste heat from the production of liquefied or solidified heat sink refrigerant for an engine in the production of fuel.
This country, and indeed the world, is currently highly dependent on the use of fossil fuels for such common uses as motor vehicle engines, home environmental controls, and industrial manufacturing. As fossil fuels are consumed more rapidly than they can be produced, we are amidst a so-called “energy crisis.” As such, there is a widely recognized need to develop new technologies to harness energy other than that gained from fossil fuel consumption. Moreover, as the burning of fossil fuels produces byproducts that are both unhealthy for individual persons and dangerous for the environment, technologies that use “clean” energy sources, or energy sources that do not produce unhealthy or dangerous byproducts upon consumption, are also in high demand. Finally, warnings of the steady increase in temperature of the earth's atmosphere, or “greenhouse effect,” advise the development of energy technology that minimizes the release of greenhouse gases, primarily CO2, and heat from the technology's operation, or “waste heat.”
Examples of such technologies abound. Common examples of technologies that exploit natural “clean” energy sources include photo-voltaic panels for capturing solar energy, wind turbines for harnessing wind energy, and geothermal systems for using heat stored within the earth. Other technologies, many focusing on motor vehicles, harness energy created by mechanical processes. Examples include recovery of vehicle deceleration, which is kinetic energy in the direction of travel; recovery of vehicle shock, which is the upward component of vehicle kinetic energy; and recovery of vehicle wind energy. Still other technologies, such as gray water heat recovery and heat recovery ventilators, focus on recycling the heat used in other operations and/or minimizing waste heat.
Some examples of such technology may use a heat exchanger. A heat exchanger is a device used to transfer heat from a fluid on one side of a barrier to a fluid on the other side of the barrier without bringing the fluids into direct contact. A common example of a heat exchanger is a motor vehicle radiator. The fluids on either side of the barrier may be gas or liquid. A heat exchanger may be used in the production, capture, or consumption of a fuel depending on the technology. For example, a gas liquefaction system, as described below, may use a heat exchanger to absorb heat in order to lower the temperature of a gas. Given its abundance, lack of expense, and relatively high heat capacity, water is often used as one of the fluids in a heat exchanger. At room temperatures, water may absorb a relatively large amount of heat before vaporizing and may continue to absorb heat as a vapor.
As mentioned above, photo-voltaic panels may capture solar energy. A solar concentrator may be used in conjunction with photo-voltaic panels to concentrate sunlight on the panels, thus increasing their efficiency. This energy absorbed by the panels may be converted into several different types of power, including electricity and water-heating means. The market average of photo-voltaic panel efficiency, measured by the energy conversion ratio is about 15%. Thus, the average photo-voltaic panel wastes about 85% of the energy it absorbs as waste heat.
Many technological efforts concerning alternative energy focus on clean motor vehicle fuels with low, or no, emissions. Among this class of technologies are those that use liquefied or solidified hydrogen, nitrogen, carbon dioxide, or other gases as a form of energy storage. Air, which is a combination of 21% oxygen, 78% nitrogen, 0.9% argon, and 0.1% other gases, may also be liquefied or solidified. In a controlled environment, heat appropriately introduced to the system will vaporize the liquefied or solidified gas, producing compressed gas that may aid a pneumatic motor with only the gas itself as exhaust. A pneumatic motor is a machine which converts energy of compressed gas into mechanical work. The liquefied or solidified gas heat sink refrigerant acts as a working fluid coolant to reduce the compression work needed to be performed by the motor compressor, which increases the efficiency of the motor. The liquefied or solidified gas may be referred to as heat sink refrigerant.
Liquefying or solidifying gas requires compression of the gas and/or lowering the temperature of the gas. Thus one method for gas liquefaction or solidification is to expose the gas to something extremely cold that will absorb the heat of the gas, thus lowering the gas's temperature. One example of this method has the gas passing in contact with vessels holding extremely cold water. The cold water will absorb the heat of the gas until the gas condenses or freezes. In this method, waste heat from the process is absorbed by and stored in the water.
Another method for gas liquefaction or solidification uses compression. A standard liquefier or solidifier of such a method operates as follows: Heat of compression is removed from the gas during compression by cooling it to the ambient temperature in a heat exchanger adjacent to the liquefier or solidifier. The gas may be positioned in contact with a solid refrigerant which may cool the gas, thus requiring less compression work. The solid refrigerant may be solid CO2. The gas is then expanded by venting into a chamber within the liquefier or solidifier. This expansion causes a lowering of the temperature and by counter-flow heat exchange of the expanded air, the pressurized air entering the expander is further cooled. With sufficient compression, flow, and heat removal, eventually droplets of liquefied gas or particles of solidified gas will form, and may be transferred from the liquefier or solidifier into a refrigerant tank. The refrigerant tank is a vacuum storage vessel that provides thermal insulation by interposing a partial vacuum between its contents and the ambient environment, such as a dewar. As explained, the gas liquefaction or solidification process produces waste heat from the removal of heat of compression from the gas. Liquefied or solidified gas may be used to power a low-emission motor vehicle or stationary motor, either directly in a fuel-less engine or indirectly by pre-compression or compression cooling of combustion air to increase engine efficiency. A liquefier or solidifier may be driven by building wind capture, direct wind capture, solar power, and/or a gas turbine, as described in U.S. patent application Ser. No. 12/315,002 to Kaufman, particularly in reference to
Other methods for gas liquefaction include magnetic refrigerator means, as described in K. Matsumoto, et al, Magnetic refrigerator for hydrogen liquefaction, J.
Gas liquefaction or solidification systems are often used in conjunction with other apparatus. For example, if the system is for liquefaction of pure oxygen or nitrogen, an air separator may be used. Such a device would separate oxygen from compressed air through a pressure swing adsorption process. This process uses a molecular sieve, which attracts nitrogen from air at high pressure and releases it at low pressure. As compressed air passes through the adsorber, the molecular sieve adsorbs nitrogen. This allows the remaining oxygen to pass through and exit the adsorbers as a product gas. Thus, the oxygen and nitrogen in air are separated.
A gas liquefaction or solidification system may also be used in conjunction with a gas turbine with refrigerated compression or pre-compression cooling. A gas turbine with refrigerated compression or pre-compression cooling may store and use liquid air, liquid nitrogen, or solid carbon dioxide at temperatures as low as 79K, 77K, and 190K, respectively, to cool atmospheric intake air. In this context, the gas liquefaction or solidification system may supply the refrigerated compression gas turbine with liquefied or solidified product. The liquefied or solidified product is used to cool compressor intake air, reducing compression work from about 50% of turbine output, as with ambient intake, to only about 10%. Gas turbines with refrigerated compression may be stationary or used in a motor vehicle. The power created by the gas turbine with refrigerated compression may be transferred into an electric generator, which may, in turn, power a battery, such as a motor vehicle battery. A stationary refrigerated compression gas turbine may operate during system off-peak times to drive the gas liquefier or solidifier.
When a motor, electric generator, and/or battery is used in conjunction with a gas liquefaction or solidification system, a power conditioner may be included within the system that electrically controls each or all of these elements. The power conditioner may control the flow of power between the system elements with which it is in communication, and to outside elements being powered by the system.
A gas liquefaction or solidification system may also be used in conjunction with a fired heater. The purpose of a fired heater is to add heat to a process fluid, which may provide heat for a-chemical reaction. The fluid to which heat may be added may be steam. A fired heater may be used specifically with the heat exchanger portion of a gas liquefaction or solidification system. The heat exchanger may provide a fluid to the fired heater, which may be further heated by the fired heater.
Methanol is commonly used as an alternative to fossil fuels. There are several commonly known methods for methanol synthesis, all of which require a carbon source. One method uses bio-mass for the necessary carbon. Bio-mass is biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels. The thermochemical production of methanol from bio-mass involves performing bio-mass pyrolysis to produce a synthesis gas rich in hydrogen (H2) and carbon monoxide (CO), which is then catalytically converted into methanol (CH3OH, or MeOH). Production of the synthesis gas is accomplished by thermal gasification.
In one version of the bio-mass method for MeOH synthesis, a fluid bed gasifier is used. The bio-mass may first be dried in a drier. Then the bio-mass is fed into the gasifier and oxygen gas and steam are injected and react with the bio-mass. This bio-mass pyrolysis reaction is endothermic and requires heat to proceed. The synthesis gas exiting the gasifier contains small amounts of impurities, including sulfur and nitrogen, which are then separated in a gas purifier. The separation also includes the removal of carbon dioxide (CO2) gas. Although CO2 reacts with H2 to produce MeOH (CO2+3H2CH3OH+H2O), it consumes more H2 per mole of MeOH formed than the reaction of CO with H2 to form CH3OH (CO+2H2
CH3OH), thus it is preferable to limit the MeOH synthesis to the CO reaction. This serves the further purpose of consuming CO, which is toxic, as compared to relatively harmless CO2. The purified synthesis gas is now rich in H2 and CO, and may react within a synthesis reactor to produce MeOH. In addition to MeOH, the synthesis reactor may also produce tail gas. Tail gas may include unreacted CO and/or H2. Alternatively, if CO2 is not eliminated from the synthesis gas during purification, tail gas may also include unreacted CO2 and/or H2O.
Methane gas is also often used as a renewable substitute for natural gas. Methanation is the process of generating methane out of a mixture of gases. It is usually performed by a similar process to that described above for methanol synthesis. In methanation, however, the main reaction is CO+3H2⇄CH4+H2O. As the reagents on one side of the reaction are the same as those required of methanol synthesis, whether the reaction produces methane or methanol depends on stoichiometry—controlling the environment of the reaction and the relative quantities of the reagents.
Hydrogen is also often used as a renewable gas to provide combustion free of carbon dioxide exhaust, especially for vehicle use. Production of hydrogen gas for such a purpose may be through the steam carbon reactions, such as C+2H2OCO2+2H2 and C+H2O
CO+H2. An in depth discussion of these and similar reactions may be found in U.S. Pat. No. 3,615,299 to Fischer et al. Another reaction that produces hydrogen gas is the water gas shift reaction CO+H2O
H2+CO2. This reaction is discussed in more detail in U.S. Pat. No. 1,505,065 to West et al.
Vapor turbines may be used to harness the thermal and/or kinetic energy of fluids. Examples of vapor turbines in the art include variable speed vapor turbines, such as disclosed in U.S. Pat. No. 3,761,197 to Kelly, and those that include corrosion resistant components for use with corrosive fluids, such as disclosed in U.S. Pat. No. 7,498,087 to Cortese.
The present invention is a system for using the waste heat produced from the production of liquefied or solidified heat sink refrigerant in the production of fuel and a method for fuel production using the system. In its most basic form, the system includes a liquefied or solidified heat sink refrigerant production system, a fuel production system, and a heat exchanger. The liquefied or solidified heat sink refrigerant production system produces waste heat which is transferred through the heat exchanger to power the fuel production system.
In a first embodiment of the present invention, the liquefied or solidified heat sink refrigerant production system includes a refrigerant cooling phase transformer and a heat exchanger. The refrigerant cooling phase transformer may be a liquefier that liquefies gas or a solidifier that solidifies gas. The system may also include an air separator, a refrigerant tank, a motor, a gas turbine with refrigerated compression, a fired heater, an electric generator, and a power conditioner.
When the refrigerant cooling phase transformer is a liquefier, the liquefier may be the Cosmodyne A400, for example. Nitrogen is the preferred gas liquefied by the liquefier. This nitrogen gas may be supplied to the liquefier by an air separator. The air separator may intake air and separate it into nitrogen and oxygen gases.
The refrigerant cooling phase transformer may deposit the heat sink refrigerant into a refrigerant tank for storage, or directly into an engine to provide compression cooling of working fluid and to support combustion. The refrigerant tank may supply heat sink refrigerant to another system, such as a refrigerant distribution system or a system that consumes heat sink refrigerant, such as a motor vehicle engine. The refrigerant tank may supply refrigerant to a gas turbine with refrigerated compression. The gas turbine with refrigerated compression may include a valve or vent for atmospheric air intake and may be supplied with tail gas from a fuel synthesis reactor. The gas turbine with refrigerated compression may pass power to an electric generator, which may pass power to a battery, such as a motor vehicle battery. A power conditioner, such as an Atkinson Electronics custom power conditioner, may control the motor and/or the electric generator. The refrigerant cooling phase transformer may be powered by the off-peak operation of the gas turbine.
The heat exchanger forms part of a liquefied or solidified heat sink refrigerant production system, and these heat exchangers may operate in combination with a fired heater, such as an ACMA GS Series Steam Superheater. The heat exchanger may be used so that it may absorb the waste heat rejected from either the liquefier or solidifier in the liquefied or solidified heat sink refrigerant production system. The liquid water to which heat is transfer through the heat exchanger preferably turns to steam. A liquid water supply may provide the heat exchanger with liquid water. The heat exchanger may use the waste heat from the liquefied or solidified heat sink refrigerant production system and/or the solar energy capture system to heat the liquid water into steam. The steam from the liquefied or solidified heat sink refrigerant production system's heat exchanger and/or the solar energy capture system's heat exchanger may be provided directly from the heat exchanger(s) to the fuel production system, or the steam may be provided first from the heat exchanger(s) to a fired heater for further heating, and then from the fired heater to the fuel production system. Thus, the heat, in the form of steam, may be supplied to the fuel production system directly or indirectly from the heat exchanger(s). Heated water that is not converted to steam for the fuel production system may be used in other applications such as home heating or water purification, for example desalination.
The fuel production system may be any fuel production system that requires heat to facilitate an endothermic reaction. The preferred embodiment is a thermal gasification system that may produce methanol, methane, ethanol, or hydrogen. It is understood, however, that the fuel production system may be any fuel production system that requires heat to facilitate an endothermic reaction, and that the system may produce hydrogen or any of several small hydrocarbon and hydrocarbon alcohol based fuels.
The basic system may include a gasifier, a gas purifier, a synthesis reactor, and condensing means, including a vapor turbine and/or a condenser. The system may also include a drier, an electric generator, and a fan. The gasifier may receive the waste heat rejected by the liquefied or solidified heat sink refrigerant production and/or the solar energy capture systems. Thus, in the preferred embodiment, the gasifier may be connected with the heat exchanger(s) and/or the fired heater such that the heat exchanger(s) and/or fired heater may supply the gasifier with steam. Oxygen gas may also be supplied to the gasifier. This oxygen gas may be supplied to the gasifier by an air separator, as described above. A source of carbon, preferably bio-mass, may also be supplied to the gasifier. The bio-mass may have been dried in a drier before being supplied to the gasifier. The thermal gasification system may be the Renugas model from Gas Technology Institute, for example.
Once the reagents are supplied to the gasifier, bio-mass pyrolysis may occur within the gasifier. The heat from the steam may act as the activation energy for the reaction. The synthesis gas product from the gasifier may then be supplied to a gas purifier, where carbon dioxide may be removed. The purified gas synthesis product from the gas purifier may then be supplied to a synthesis reactor. The synthesis product gases from the synthesis reactor may include the desired fuel gas and tail gas. When the product gas is methanol, the synthesis reactor may be the Hydro-Chem Methanol Synthesis Reactor, for example. Tail gas may then be supplied back to the gasifier. Tail gas may also be supplied to the fired heater. Tail gas may also be supplied to a gas turbine with refrigerated compression that may be part of the liquefied or solidified heat sink refrigerant production system.
The desired fuel gas is preferably methanol or methane. In the preferred system, the gas may be supplied to a vapor turbine, such as the Barber Coleman Vapor Turbine. The energy harnessed from the vapor turbine may power the electric generator. This electric generator may be controlled by the power conditioner that may be part of the liquefied or solidified heat sink refrigerant production system. Some or all of the desired fuel gas may condense upon being supplied to the vapor turbine to form liquid methanol or methane. Any desired fuel gas not condensed by the vapor turbine may then be supplied to a condenser. A fan with an air vent may aid the condenser. Exhaust from tail gas burned in the fired heater may be supplied to the fan. The condenser may condense the supplied desired fuel gas to produce liquid methanol or methane. In another embodiment of the preferred system, the desired fuel gas may be supplied directly from the synthesis reactor to the condenser. Thus condensing means may include the vapor turbine and the condenser.
Although a thermal gasification system for methanol or methane production is presented as the preferred embodiment of the fuel production system, the present invention contemplates the use of any fuel production system that requires heat to facilitate an endothermic reaction.
In a second embodiment of the present invention, the system includes a solar energy capture system in addition to the liquefied or solidified heat sink refrigerant production system. The energy captured from this system may be converted to electricity, which may be used to partly or wholly power the liquefied or solidified heat sink refrigerant production system. The solar energy capture system may also provide heat to the fuel production system, in addition to the waste heat rejected by the liquefied or solidified heat sink refrigerant production system. The solar energy capture system may include a solar panel and a heat exchanger. The solar panel is preferably a photo-voltaic panel. The system may also include a power conditioner that controls the photo-voltaic panel. It may also include a solar concentrator to increase the efficiency of the photo-voltaic panel and/or increase the heat that may be supplied to the heat exchanger. The system may be the Spectrolab Solar Cell, for example. In this second embodiment of the present invention, a second heat exchanger is in communication with the solar panel so that waste heat from the solar panel may be absorbed and used to heat liquid water into steam as described above in reference to the first embodiment.
In other embodiments, including the third and fourth embodiments, of the present invention, CO2 is sequestered by solidification for use as a refrigerant in a gas turbine system. Use of CO2 refrigerant is selected for its high latent heat of sublimation to improve the economy of refrigerant production by providing CO2 sequestration from earth's atmosphere ranging from 0.12 to 0.36 pounds per pound of intake air. These embodiments may or may not include a solar energy capture system. In the third embodiment of the present invention, the system includes both a liquefier and a solidifier. The liquefier produces liquid N2 to be used for motor vehicle gas turbine refrigerant, as described above. The solidifier is in fluid communication with the gas purifier in the thermal gasification system. CO2 gas is provided by the gas purifier to the solidifier, and sequestered from the atmospheric air. The CO2 gas is then solidified and may be used as refrigerant in gas turbine stations, such as the one described below in reference to another CO2 sequestration embodiment.
In a fourth embodiment of the present invention involving CO2 sequestration, the refrigerant cooling phase transformer is a solidifier, and instead of CO2 gas being released from the gas purifier as waste, it is sequestered from the atmospheric air and provided to the solidifier. Thus, the refrigerant tank stores and distributes solid CO2 to a gas turbine, a system for distribution of refrigerant, or storage. In the preferred version of this embodiment, the solid CO2 is provided from the solidifier to a gas turbine compression cooling system to be used as refrigerant. The CO2 sublimates during its use as refrigerant for the gas turbine compression cooling system and then passes as a gas through a chiller, where it absorbs heat from atmospheric air, and then travels back to the solidifier in a loop. At the same time, atmospheric air passes through the chiller in the other direction, and is provided to the motor-compressor of the gas turbine compression cooling system. The atmospheric air is further cooled by its thermal communication with the solid CO2. The compressed atmospheric air then proceeds to a compressed air tank and/or through a recuperator. The recuperator is a regenerative device that raises the temperature of the compressed atmospheric air. A heat input then further heats the atmospheric air. The heat input may be a combuster or solar energy capture device, for example. The heated air is then introduced to a turbine-generator. The exhaust heat emitted by the turbine-generator is provided to the recuperator. Energy harnessed from the turbine-generator is provided to a power conditioner which may provide power to the motor-compressor, an electric motor that powers the solidifier, an electric motor that powers a liquefier discussed below, other devices, and the electric grid.
In the preferred version of the fourth embodiment, the fuel production system produces hydrogen, rather than methanol or methane. The synthesis reaction is a steam carbon or water gas shift reaction. After the CO2 gas is sequestered and provided to the solidifier, any remaining carbon is recycled as tail gas to the gasifier and/or fired heater. A hydrogen liquefier is in communication with the synthesis reactor of the thermal gasification system and is powered by the power conditioner as discussed above. H2 gas is provided from the synthesis reactor to the liquefier, where it is liquefied. The liquefier may be in communication with a storage vessel for the H2 liquid, or it may provide the H2 liquid to a system that may use it as fuel.
The fourth embodiment may also include a solar heater and bypass valve in series with the heat exchanger and in parallel with the fired heater. During daylight hours, steam may be further heated by the solar heater, which has no harmful emissions. This solar heating lessens the necessity to use the fired heater, which produces CO2 as a byproduct of its use. During non-daylight hours, the bypass valve allows the steam to travel directly from the heat exchanger to the fired heater.
Therefore it is an aspect of this invention to provide an improved system and method for producing alternative fuels to fossil fuels.
It is a further aspect of this invention to provide an improved system and method for producing “clean” fuels.
It is a further aspect of this invention to provide an improved system and method for reducing the loss of waste heat in liquefied or solidified heat sink refrigerant production.
It is a further aspect of this invention to provide an improved system and method for reducing the loss of waste heat in solar energy capture systems.
It is a further aspect of this invention to provide an improved system and method for using the waste heat rejected from the production of liquefied or solidified heat sink refrigerant to power the production of fuel.
It is a further aspect of this invention to provide a system that sequesters waste CO2 away from the atmosphere and solidifies it into refrigerant that can be used for compression cooling in motor vehicle and stationary gas turbines.
These aspects of the invention are not meant to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the following description, appended claims, and accompanying figures.
Liquefied or solidified heat sink refrigerant production system 20 may comprise refrigerant cooling phase transformer 22, refrigerant tank 24, heat exchanger 26, liquid water supply 28, gas turbine 30 with refrigerated compression, first generator 32, power conditioner 36, electric motor 38, air separator 40, and fired heater 42. Refrigerant cooling phase transformer 22 may preferably be a liquefier that liquefies gas or a solidifier that solidifies gas. If refrigerant cooling phase transformer 22 is a liquefier, it preferably liquefies nitrogen gas, thus the heat sink refrigerant 45 is liquefied nitrogen. If refrigerant cooling phase transformer 22 is a solidifier, it preferably solidifies carbon dioxide gas, thus the heat sink refrigerant 45 is solidified carbon dioxide. Refrigerant cooling phase transformer 22 may be powered by electric motor 38. Atmospheric air 75 may be separated into nitrogen 41 and oxygen 43 gases by air separator 40. If refrigerant cooling phase transformer 22 is a liquefier, separator 40 may supply nitrogen gas 41 to refrigerant cooling phase transformer 22. The waste heat rejected by the phase transformation may be absorbed by heat exchanger 26 through liquid water 47 provided to heat exchanger 26 by liquid water supply 28. Although this preferred embodiment includes liquid water supply 28, it is understood that a supply of any liquid that may absorb waste heat rejected by the refrigerant cooling phase transformation such that the liquid will vaporize and may be transferred to thermal gasification system 60 may be used.
Refrigerant cooling phase transformer 22 may provide heat sink refrigerant 45 to refrigerant tank 24 for storage. Refrigerant tank 24 may supply heat sink refrigerant 45 to a system for distribution of refrigerant (not shown) or to a system that uses refrigerant as working fluid coolant to reduce compression work, such as a prime mover of a motor vehicle (not shown). Refrigerant tank 24 may also supply heat sink refrigerant 45 to a gas turbine 30 with refrigerated compression to reduce compression work. Gas turbine 30 with refrigerated compression may comprise an air valve or vent (not shown) for introduction of working fluid in the form of atmospheric air 75 and/or a valve or vent (not shown) for introduction of tail gas 67 from thermal gasification system 60. Off-peak operation of gas turbine 30 may provide power for liquefied or solidified heat sink refrigerant production system 20. First electric generator 32 may provide power generated by gas turbine 30 with refrigerated compression. First electric generator 32 may electrically power a battery (not shown). Power conditioner 36 may control electric motor 38, first electric generator 32, and/or a battery.
Waste heat rejected by liquefied or solidified heat sink refrigerant production system 20 and absorbed by heat exchanger 26 may heat liquid water 47 provided to heat exchanger 26 by liquid water supply 28. Heat exchanger 26 may use the waste heat to convert liquid water 47 into steam 29. Steam 29 may be provided to fired heater 42, which may further heat steam 29. Although only heat exchanger 26, and heat exchanger 26 in combination with fired heater 42, are included in this embodiment, it is understood that any means of transferring heat commonly used in the art may be used with the present invention.
Thermal gasification system 60 may comprise drier 68, gasifier 62, gas purifier 64, methanol synthesis reactor 66, methanol vapor turbine 70, second electric generator 72, condenser 74, and fan 76. Drier 68 may dry bio-mass 61. Drier 68 may provide dried bio-mass 61− (bio-mass 61 minus water/moisture) to gasifier 62. Fired heater 42 may provide steam 29+ (steam 29 plus additional heat) to gasifier 62. Air separator 40 may provide oxygen gas 43 to gasifier 62. Once provided with these reagents, and the heat from steam 29+ for activation energy, gasifier 62 may produce synthesis gas 63 and provide it to gas purifier 64. Gas purifier 64 may remove carbon dioxide 65 from synthesis gas 63, and provide purified synthesis gas 69 to methanol synthesis reactor 66. Methanol synthesis reactor 66 may produce methanol gas 71 and tail gas 67. Tail gas 67 may be provided to gasifier 62, fired heater 42, and/or gas turbine 30 with refrigerated compression.
Methanol synthesis reactor 66 may provide methanol gas 71 to methanol vapor turbine 70. Methanol vapor turbine 70 may be powered by the flow of methanol gas 71 from methanol synthesis reactor 66. Methanol vapor turbine 70 may cause some or all of methanol gas 71 to condense into liquid methanol 73. This is one way in which the product of thermal gasification system 60 may be formed. Second electric generator 72 may be controlled by power conditioner 36. Second electric generator 72 may provide or store to a battery (not shown) the power generated from the provision of methanol gas 71 to methanol vapor turbine 70. Any of methanol gas 71 not condensed into liquid by methanol vapor turbine 70 may be provided to condenser 74. Condenser 74 may condense remaining methanol gas 71 into liquid methanol 73. This is another way in which the product of thermal gasification system 60 may be formed. Fan 76 may provide atmospheric air 75 to condenser 74. Burned exhaust 77 from fired heater 42 may heat atmospheric air 75 being provided to fan 76. Although only the condensing means of methanol vapor turbine 70 and condenser 74 are included in this embodiment, it is understood that any condensing means commonly used in the art may be used with the present invention.
Although thermal gasification system 60 is presented as the preferred embodiment of the fuel production system of the present invention, it is understood that any fuel production system that requires heat to facilitate an endothermic reaction may be used. Moreover, although methanol is presented as the desired fuel product of the fuel production system, it is understood that the desired fuel product may be any of several hydrocarbon or hydrocarbon alcohol based fuels, such as methane and ethanol.
Electrical power from first electric generator 32 during off-peak operation of gas turbine 30 with refrigerated compression, may be supplied to power conditioner 36, which may combine the varying power from first electric generator 32 into a stable power output. Refrigerant cooling phase transformer/liquefier 22 may produce waste heat that may be captured and used for fuel production. In some embodiments, power conditioner 36 may include a rheostat and an inverter, which may convert the direct current electrical power into alternating current. In others, it may include a deep current battery that may accept the various power inputs and may provide a constant direct current output. The power conditioner 36 may provide power to refrigerant cooling phase transformer/liquefier 22 which may take in nitrogen gas from separator 40, liquefy the nitrogen gas, and supply liquefied heat sink refrigerant 45 to a refrigerant tank 24. Although nitrogen is presented as the preferred gas for liquefaction, it is understood that other pure and composite gases, such as hydrogen and air, may also be used for liquefaction. Refrigerant tank 24 is preferably a dewar, or other cryogenic tank that may maintain the liquefied heat sink refrigerant 45 in a liquid state. Liquefied heat sink refrigerant 45 from the refrigerant storage tank 24 may be used in other applications, such as vehicle operation.
Now referring to
Refrigerant cooling phase transformer 22 may provide heat sink refrigerant 45 to refrigerant tank 24 for storage. Refrigerant tank 24 may supply heat sink refrigerant 45 to a system for distribution of refrigerant (not shown) or to a system that consumes refrigerant as coolant to reduce compression work, such as a prime mover of a motor vehicle (not shown).
Waste heat rejected by liquefied or solidified heat sink refrigerant production system 20 and absorbed by first heat exchanger 26 may heat liquid water 47 provided to first heat exchanger 26 by liquid water supply 28. First heat exchanger 26 may use the waste heat to convert liquid water 47 into first steam 29. First steam 29 may be provided to fired heater 42, which may further heat first steam 29.
Solar energy capture system 50 may comprise second heat exchanger 52, photo-voltaic panel 54, solar concentrator 56, liquid water supply 28, and power conditioner 36. Photo-voltaic panel 54 may absorb sunlight. Solar concentrator 56 may concentrate sunlight on photo-voltaic panel 54 to increase the efficiency of photo-voltaic panel 54 and increase the amount of heat that may be provided to second heat exchanger 52. The sunlight absorbed by photo-voltaic panel 54 may be converted to electricity, which may be controlled by power conditioner 36, and provided to liquefied or solidified heat sink refrigerant production system 20 to power electric motor 38. Any waste heat absorbed by photo-voltaic panel 54, but not converted into electricity may be absorbed by second heat exchanger 52 through liquid water 47 provided to second heat exchanger 52 by liquid water supply 28.
Waste heat rejected by solar energy capture system 50 and absorbed by second heat exchanger 52 may heat liquid water 47 provided to second heat exchanger 52 by liquid water supply 28. Heat exchanger 52 may use the waste heat to convert liquid water 47 into second steam 53. Although
Thermal gasification system 60 comprises drier 68, gasifier 62, gas purifier 64, methanol synthesis reactor 66, methanol vapor turbine 70, electric generator 72, condenser 74, and fan 76. Drier 68 may dry bio-mass 61. Drier 68 may provide dried bio-mass 61− (bio-mass 61 minus water/moisture) to gasifier 62. Fired heater 42 may provide first steam 29+ (first steam plus additional heat) to gasifier 62. Second heat exchanger 52 may provide second steam 53 to gasifier 62. Air separator 40 may provide oxygen gas 43 to gasifier 62. Once provided with these reagents, and the heat from first steam 29+ and second steam 53 for activation energy, bio-mass pyrolysis may occur within gasifier 62 and may produce synthesis gas 63, which may be provided to gas purifier 64. Gas purifier 64 may remove carbon dioxide 65 from synthesis gas 63, and provide purified synthesis gas 69 to methanol synthesis reactor 66. Methanol synthesis reactor 66 may produce methanol gas 71 and tail gas 67. Tail gas 67 may be provided to gasifier 62 and/or fired heater 42.
Methanol synthesis reactor 66 may provide methanol gas 71 to methanol vapor turbine 70. Methanol vapor turbine 70 may be powered by the flow of methanol gas 71 from methanol synthesis reactor 66. Methanol vapor turbine 70 may cause some or all of methanol gas 71 to condense into liquid methanol 73. This is one way in which the product of thermal gasification system 60 may be formed. Electric generator 72 may be controlled by power conditioner 36. Electric generator 72 may provide or store in a battery (not shown) the power generated from the provision of methanol gas 71 to methanol vapor turbine 70. Any of methanol gas 71 not condensed by methanol vapor turbine 70 may be provided to condenser 74. Condenser 74 may condense remaining methanol gas 71 into liquid methanol 73. This is another way in which the product of thermal gasification system 60 may be formed. Fan 76 may provide atmospheric air 75 to condenser 74. Burned exhaust 77 from fired heater 42 may heat atmospheric air 75 to fan 76. Although only the condensing means of methanol vapor turbine 70 and condenser 74 are included in this embodiment, it is understood that any condensing means commonly used in the art may be used with the present invention.
Now referring to
Now referring to
System 200 includes gas turbine compression cooling system 108. Gas turbine compression cooling system 108 includes motor-compressor 94 inside of refrigerant tank 78, compressed air tank 96, recuperator 98, heat input 104, turbine-generator 102, and chiller 106. Motor-compressor 94 may be a working fluid compressor. Carbon dioxide is sequestered from the atmosphere by proceeding through a loop connecting gas turbine compression cooling system 108 with solidifier 92. Solidifier 92 provides CO2 solid 79 to refrigerant tank 78. This essentially packs dry ice around motor-compressor 94 to absorb heat from atmospheric air 75 as it is compressed by motor-compressor 94. After absorbing the heat, the carbon dioxide leaves refrigerant tank 78 as CO2 gas 65, still sequestered from the atmosphere, and is provided to chiller 106. Chiller 106 is a counter flow heat exchanger that uses CO2 gas 65 as a heat sink to cool atmospheric air 75 traveling through chiller 106 in the opposite direction. CO2 gas 65 is provided back to solidifier 92, completing the loop.
As mentioned above, chiller 106 also takes in atmospheric air 75 and chills it before it is provided to motor-compressor 94 for compression aided by CO2 solid 79. The compressed atmospheric air 75 then travels to compressed air tank 96, where it may be stored, or provided to recuperator 98. Recuperator 98, is a counter flow heat exchanger that uses exhaust heat from turbine-generator 102 to heat atmospheric air 75. Atmospheric air 75 is further heated by heat input 104. Heated atmospheric air 75 is then provided to turbine-generator 102. The power produced by turbine-generator 102 is provided to power conditioner 36, which, in turn, powers motor-compressor 94, first electric motor 38, which powers solidifier 92, and second electric motor 86, which powers hydrogen liquefier 82. Power conditioner 36 may also power other devices (not shown) as indicated by the arrow pointing out of power conditioner 36, but not at a specific device.
System 200 may also include solar heater 88 and bypass valve 90 positioned proximate to heat exchanger 26 and in parallel with fired heater 42. During daylight hours, solar heater 88 may absorb heat from the sun to heat steam 29 coming from heat exchanger 26. It is preferable to limit the use of fired heater 42 in heating steam 29, in favor of devices such as solar heater 88 that have no emissions, as fired heater 42 produces carbon dioxide and other emissions during use. At night, when solar heater 88 cannot provide heat, steam 29 may skip over solar heater 88 through bypass valve 90. It is understood in all embodiments of the present invention, that although fired heater 42 and solar heater 88 are presented as preferred secondary heat sources to further heat steam 29 and/or steam 53, and secondary heat source capable of heating steam may be substituted.
System 200 may also include gasifier recuperator 110 when system 200 includes a secondary heat source, such as solar heater 88 and/or fired heater 42. Gasifier recuperator 110 is positioned between heat exchanger 26 and gasifier 62 such that unreacted steam from gas purifier 64 is recycled to gasifier recuperator 110 for transfer of heat to increase the temperature of steam 29 entering gasifier recuperator 110 from heat exchanger 26. The pre-heated steam may then be provided to gasifier 62 via a secondary heat source, while the recycled steam cools in gasifier recuperator 110. The steam discharge from gasifier recuperator 110 may be condensed in condensor 112 and the condensate returned to liquid water supply 28, or provided for other applications such as building heat or purified water. Bio-mass byproducts 85 may also be recovered from the system. Bio-mass byproducts 85 may be tar and ash derived from the burning of bio-mass 61.
Although the depiction shown in
Although the present invention has been described in considerable detail with reference to certain versions thereof, other versions would be readily apparent to those of ordinary skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
This application is a continuation in part of co-pending U.S. Non-Provisional patent application Ser. No. 12/592,826, filed on Dec. 3, 2009.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12592826 | Dec 2009 | US |
| Child | 12807086 | US |
