US20180058266A1

US20180058266A1 - Methods and systems for the storage of nuclear energy in increased energy density coal

Info

Publication number: US20180058266A1
Application number: US15/619,868
Authority: US
Inventors: Michael D. Durham
Original assignee: Soap Creek Energy
Current assignee: Soap Creek Energy
Priority date: 2016-08-30
Filing date: 2017-06-12
Publication date: 2018-03-01
Also published as: US20180057763A1; US20180058265A1

Abstract

Systems and methods to reduce the emissions of carbon dioxide associated with coal fired power plants by using electricity from a nuclear power plant to power a coal processing plant that reduces the moisture content of coal resulting in an increased energy density beneficiated coal are provided. The system includes a source of electricity from a nuclear power plant; a coal processing plant configured to reduce the moisture content of the coal by a beneficiation process to produce an increased energy density coal; and a coal-fired power plant configured to convert the increased energy density coal to electricity on demand at a higher efficiency with reduced emissions of carbon dioxide.

Description

FIELD OF THE INVENTION

This invention relates to methods and systems for the storage of non-carbon nuclear energy in solid fuels, in particular coal. More particularly, the invention relates to using electricity generated from nuclear power plants to supply electrical power to coal processing plants and to assist in the beneficiation of coal to produce an increased energy density coal, which reduces the carbon footprint of the combined electrical generation process.

BACKGROUND OF THE INVENTION

Currently, fossil fuels generate both the electricity and the thermal energy needed to remove moisture and dry coal in a coal processing plant. Due to rising concerns about the impact on climate from increased carbon dioxide (CO₂) emissions from fossil fuel combustion, there has been a worldwide effort to curb emissions of carbon dioxide in the generation of electrical power by either capturing and storing the carbon (CCS), or by switching from coal-burning production plants to renewable electrical energy power/electricity generation, or by increasing the efficiency of generation. CCS technologies are relatively new and unproven and are associated with high costs and high energy penalties. While renewable electrical energy produces electricity without carbon emissions, the renewable generation sources suffer from several drawbacks that limit their usefulness as alternatives to fossil fuel. Power generation by renewable electrical energy sources may be intermittent and inconsistent and can vary seasonally, diurnally, or be subject to instantaneous interruption depending on whether the wind is blowing or the sun is shining. Thus, renewable electrical energy sources of power are unpredictable because of their dependence upon micro- and macro-climatic conditions. Because the power generation from renewables may be intermittent and inconsistent, the power generation may or may not coincide with the timing of demand from power consumers, e.g. at night for solar power sources. Additionally, the optimum locations for renewable generation, such as the desert areas in the West maximize solar generation and remote areas of Wyoming and the Dakotas for wind, are not located near population or industrial centers, creating issues in the transmission of the electricity to places where it is needed. Moreover, the intermittency creates rapid response requirements for conventional power generation that produces stress on equipment and limits how much renewable electrical energy can be effectively integrated onto the energy supply grid. The alternative to these processes to reduce carbon dioxide emissions is to increase generation efficiency by reducing the water content of coal through drying and beneficiation technologies. However, coal beneficiation requires significant amounts of electrical energy to dry the coal, which is produced from burning fossil fuel that has its own carbon emissions.
In a detailed analysis of how to move toward a low-carbon energy future, the Clean Air Task Force found that trying to accomplish this with just the addition of renewable electrical energy sources and energy storage would be technically impractical and cost prohibitive. They concluded that in order to maintain the reliability of the electricity supply while keeping costs reasonable “zero carbon baseload and dispatchable capacity (e.g. nuclear, decarbonized fossil) will likely be essential to deep carbon reductions.” One alternative to accomplish this is to integrate electricity generated by nuclear power plants with electricity generation from coal-fired power plants so that they work seamlessly together.
Nuclear power is one process that can produce consistent electricity to the grid without generating emissions of carbon dioxide. However, the nuclear power plants are experiencing difficulties as renewable electrical energy sources are added to the grid. Nuclear power plants are designed to operate at near constant load conditions without cycling with demand. However, when the variability of energy generated by renewables such as solar or wind causes fluctuations in electricity supply, nuclear power plants cannot respond quickly enough to the variability created by these renewables.
In addition, renewables often receive favorable financial subsidies that allow them to operate at lower costs. Therefore, when renewable electrical energy is added to the grid it displaces the need for electricity generated by nuclear power plants because the subsidies for renewables make them less expensive. The addition of greater amounts of renewable electrical energy could ultimately results in the shutdown of some nuclear power plants. If this occurs, the amount of power supplied by these plants will have to be replaced by new base-load plants, most likely burning fossil fuels, resulting in increased emissions of carbon dioxide.
One method to decrease the amount of emissions of carbon dioxide from coal-fired power plants is to beneficiate and/or dry the coal prior to combustion. This results in a higher density of energy in the coal, which reduces the volume of coal required to produce a given amount of electricity, thus reducing the carbon emissions associated with that electrical generation. However, the various coal beneficiation/drying processes all require significant amounts of electrical and thermal energy to dry the coal. If these energy sources are associated with carbon dioxide generating processes, the overall environmental improvement from coal drying is reduced or even eliminated in some cases.
A need exists to use the electricity produced from nuclear energy to supply power to the coal processing plant. A need also exists to use electricity produced from nuclear energy to operate equipment used in the beneficiation and drying of coal. A need also exists to provide systems and methods of using electricity generated by nuclear energy in the coal processing plant in order to reduce the overall carbon emissions associated with coal processing plants. A need also exists to maintain the financial competitiveness of nuclear energy with renewables and thermal energy sources thereby maintaining grid reliability by providing electricity on demand and keeping electricity affordable. A need also exists to interface nuclear energy with electrical power from other renewable electrical energy sources such as solar, wind and hydro and thermal energy from biomass combustion, geothermal, solar thermal and waste energy with coal beneficiation and drying to produce an increased energy density coal with a minimized carbon footprint.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the foregoing needs by providing systems and methods for interfacing nuclear energy with coal beneficiation and drying processes supplementing energy supplied by renewable and other non-carbon sources to produce an increased energy density coal. Because nuclear power is a non-carbon source of electricity this will reduce the carbon emissions associated with the beneficiation of coal while also providing for the short to long-term storage of low carbon energy with subsequent conversion to energy on demand as and when needed.
The invention results in reduced CO₂emissions in several different ways. By providing a nuclear energy source to power the coal processing plant by providing electricity to operate mechanical and electrical equipment used in the beneficiation and drying of coal, the beneficiation process has a lowered CO₂output. Furthermore, beneficiated and dried coal produces less CO₂per unit of electricity generated than non-beneficiated coal due to the increased stored energy content of beneficiated coal and the reduced energy loses during combustion due to latent heat of vaporization of water in the coal. The reduced volume of coal burned to produce a given quantity of electricity also reduces parasitic losses in the plant, which leads to additional reductions in CO₂emissions. Thus, the use of electricity from nuclear power to beneficiate and dry coal will result in a greater decrease in overall carbon emissions than just supplying the nuclear power electricity to the grid.
Advantageously, the invention may be used alone by providing electricity to power the coal processing plant or may be integrated with renewable electrical energy sources such as solar, wind, hydro, and wave energy; and/or non-carbon thermal energy sources, such as solar, geothermal, biomass combustion, and waste energy. The invention may also be used in conjunction with both renewable electrical energy sources and non-carbon thermal energy sources when those sources are used in beneficiating coal.
Accordingly, in some aspects, the present invention is directed to systems and methods of supplying electricity from a nuclear power source to a coal processing plant. In some aspects, the coal may include peat coal, lignite coal, sub-bituminous coal, bituminous coal, anthracite coal and combinations of the foregoing. In some aspects, the system and method comprises providing electricity provided by nuclear energy sources to dry and beneficiate coal. In some aspects, the system and method comprises providing a nuclear energy source to supply electricity to the coal processing plant in combination with electricity from renewable electrical energy sources used in the beneficiation and drying of coal such as solar, wind, hydro and wave energy. In some aspects the system and method comprises providing a nuclear energy source to supply electricity to the coal processing plant in combination with non-carbon thermal energy sources, such as solar, geothermal, biomass combustion and waste energy used to dry and beneficiate coal. In some aspects the system and method comprises providing a nuclear energy source to supply electricity to the coal processing plant in combination with one or more renewable electrical energy sources and one or more non-carbon thermal energy sources used to dry and beneficiate coal.
In some aspects, a system to reduce the emissions of carbon dioxide associated with coal fired power plants by using electricity from a nuclear power plant to power a coal processing plant that reduces the moisture content of coal resulting in an increased energy density beneficiated coal is provided. In some aspects, the system includes a source of electricity from a nuclear power plant; a coal processing plant configured to reduce the moisture content of the coal by a beneficiation process to produce an increased energy density coal; and a coal-fired power plant configured to convert the increased energy density coal to electricity on demand at a higher efficiency with reduced emissions of carbon dioxide.
In some aspects, the coal processing plant uses mechanical energy including compression to dry the coal. In some aspects, the coal processing plant is configured to utilize microwave energy to reduce the moisture content of the coal.
In some aspects, the system includes electricity from a renewable electrical energy source configured to supplement the electricity generated by the source of nuclear energy for beneficiating and drying the coal. In some aspects, the renewable electrical energy source is selected from hydroelectric power, solar power, wind power, and wave power, and combinations thereof.
In some aspects, the system includes a supplemental source of thermal energy configured to be used in the beneficiation process to supplement the source of electricity from the nuclear power plant supplied to the coal processing plant. In some aspects, the supplemental source of thermal energy is combustion of fossil fuels. In some aspects, the supplemental source of thermal energy is waste heat. In some aspects, the supplemental source of thermal energy is a non-carbon thermal energy source. In some aspects, the non-carbon thermal energy source is selected from a solar thermal energy source, a geothermal energy source, a biomass energy source and combinations of the foregoing.
In some aspects, a location of the coal processing plant is selected from a coal mine, a coal transportation terminal, a coal-fired power plant, a same site as the non-carbon thermal energy source and combinations of the foregoing. In some aspects, the coal transportation terminal is selected from terminals that provide access to a ship, barge, rail, truck and combinations of the foregoing. In some aspects, the coal processing plant is integrated with a coal-fired power plant and shares use of coal handling, coal crushing and coal conveying equipment.
In some aspects, the increased energy density coal is configured to be stored, transported and later combusted to produce said electricity on demand.
In some aspects, the supplemental thermal energy source is configured to preheat the coal prior to processing.
In some aspects, a system to store electricity generated by a nuclear power plant by using the electricity to power a coal processing plant to decrease the moisture content of coal resulting in an increased energy density beneficiated coal that can be later combusted to produce electricity on demand is provided. The system may include electrical energy from a nuclear power plant, a coal preparation plant, wherein the electrical energy from the nuclear power plant is stored in an increased energy density beneficiated coal; and a coal-fired power plant configured to recover the stored energy by combusting the coal to produce electricity on demand at an increased efficiency.
In some aspects, a source of mechanical energy including compression is used for beneficiating the coal.
In some aspects, the coal processing plant is configured to use microwave energy to decrease the moisture content of the coal.
In some aspects, the system includes a renewable electrical energy source for supplementing the electricity generated by the source of nuclear energy to beneficiate and dry the coal. In some aspects, the renewable electrical energy source is selected from hydroelectric power, solar power, wind power, and wave power, and combinations thereof.
In some aspects, the system further includes a source of thermal energy to supplement the electricity generated by the source of nuclear energy to beneficiate and dry the coal. In some aspects, the source of thermal energy is combustion of fossil fuels. In some aspects, the source of thermal energy is waste heat. In some aspects, the source of thermal energy is a non-carbon thermal energy source. In some aspects, the non-carbon thermal energy source is selected from a solar thermal energy source, a geothermal energy source, a biomass energy source and combinations of the foregoing. In some aspects, the source of thermal energy is configured to preheat the coal prior to processing.
In some aspects, a location of the coal processing plant is selected from a coal mine, a coal transportation terminal, a coal-fired power plant, a same site as the non-carbon thermal energy source and combinations of the foregoing. In some aspects, the coal transportation terminal is selected from terminals providing access to a ship, barge, rail, truck and combinations of the foregoing. In some aspects, the coal processing plant is integrated with a coal-fired power plant and shares use of coal handling, coal crushing and coal conveying equipment.
In some aspects, the increased energy density beneficiated coal is configured to be stored, transported and later combusted to produce said electricity on demand.
In some aspects, the source of thermal energy is combustion of fossil fuels. In some aspects, the source of thermal energy source is waste heat. In some aspects, the source of thermal energy is a non-carbon thermal energy source. In some aspects, the non-carbon thermal energy source is selected from a solar thermal energy source, a geothermal energy source, a biomass energy source and combinations of the foregoing.
In some aspects, a location of the coal processing plant is selected from a coal mine, a coal transportation terminal, a coal-fired power plant, a same site as the non-carbon thermal energy source and combinations of the foregoing. In some aspects, the coal transportation terminal is selected from terminals providing access to a ship, barge, rail, truck and combinations of the foregoing. In some aspects, the coal processing plant is integrated with a coal-fired power plant and shares use of coal handling, coal crushing and coal conveying equipment.
In some aspects, the increased energy density beneficiated coal is configured to be stored, transported and later combusted to produce said electricity on demand. In some aspects, the source of thermal energy source is configured to preheat the coal prior to processing.
In some aspects, the electricity provided by a nuclear source may be used to operate mechanical and electrical systems such as equipment used in grinding, milling, crushing, pulverizing, kneading, blending, high-pressure compression, compaction and the like that physically disrupt the coal to release moisture after which it may be further dried, if necessary, by one or more renewable electrical energy sources, one or more non-carbon thermal energy sources or both.
In some aspects, the electricity provided by a nuclear source may be used to operate electrical systems such as equipment such as microwave generators that excite the water in the coal to enhance the release moisture after which it may be further dried, if necessary, by one or more renewable electrical energy sources, one or more non-carbon thermal energy sources or both.
In some aspects, the present invention is directed to systems and methods for providing electricity from nuclear power to operate the coal beneficiation and drying processes that are designed to increase the stored energy content of coal. In other aspects the present invention is directed to decreasing emissions of carbon dioxide from coal processing plants by providing electricity generated by a nuclear power source in conjunction with methods and systems disclosed in U.S. application Publn. Nos. [Attorney Docket No. 161487.00002 entitled Methods and Systems for Storage of Renewable Energy Sources in Increased Energy Density Coal, filed on Jun. 12, 2017 and Atty. Docket No. 161487.00003 entitled Methods and Systems for Decreasing Emissions of Carbon Dioxide from Coal-Fired Power Plants, filed Jun. 12, 2017], hereby incorporated by reference in their entireties. In some aspects, the electricity generated by nuclear energy may be used to operate the coal processing plant that uses beneficiating processes that use any kind of energy to dry coal including electricity generated from any source. In some aspects, the coal may include peat coal, lignite coal, sub-bituminous coal, bituminous coal, anthracite coal and combinations of the foregoing. In some aspects, the method to provide nuclear energy comprises providing electricity generated by nuclear power plants to the coal processing plant.
In some aspects, the electricity produced by a nuclear power plant may be integrated in the coal processing plant with other sources of thermal energy used in the coal drying process. In some aspects, other sources of energy, such as renewables and/or non-carbon thermal sources may be used to heat the coal at temperatures below 120 degrees C. In some aspects, the coal is heated at temperatures below 115 degrees C. In some aspects, the coal is heated at temperatures below 150 degrees C. In some aspects, the coal is heated at temperatures below 145 degrees C. In some aspects, the coal is heated at temperatures below 140 degrees C. In some aspects, the coal is heated at temperatures below 135 degrees C. In some aspects, the coal is heated at temperatures below 130 degrees C. In some aspects, the coal is heated at temperatures below 125 degrees C. In some aspects, the coal is heated at temperatures below 120 degrees C. In some aspects, the coal is heated at temperatures below 115 degrees C. In some aspects, the coal is heated at temperatures below 110 degrees C. In some aspects, the coal is heated at temperatures below 100 degrees C. In some aspects, the coal is heated at temperatures below 95 degrees C. In some aspects, the coal is heated at temperatures below 90 degrees C. In some aspects, the coal is heated at temperatures below 85 degrees C. In some aspects, the coal is heated at temperatures below 80 degrees C.
In some aspects, electricity produced by the nuclear power plant may be used to operate the coal processing plant while other sources of energy are used to beneficiate and heat the coal. In some aspects, the coal may be heated at temperatures above 125 degrees C. In some aspects, the coal is heated at temperatures above 130 degrees C. In some aspects, the coal is heated at temperatures above 135 degrees C. In some aspects, the coal is heated at temperatures above 140 degrees C. In some aspects, the coal is heated at temperatures above 150 degrees C. In some aspects, the coal is heated at temperatures above 160 degrees C. In some aspects, the coal is heated at temperatures above 165 degrees C. In some aspects, the coal is heated at temperatures above 170 degrees C. In some aspects, the coal is heated at temperatures above 175 degrees C. In some aspects, the coal is heated at temperatures above 180 degrees C. In some aspects, the coal is heated at temperatures above 185 degrees C. In some aspects, the coal is heated at temperatures above 190 degrees C. In some aspects, the coal is heated at temperatures above 195 degrees C. In some aspects, the coal is heated at temperatures above 200 degrees C. In some aspects, the coal is heated at temperatures above 205 degrees C. In some aspects, the coal is heated at temperatures above 210 degrees C. In some aspects, the coal is heated at temperatures above 215 degrees C. In some aspects, the coal is heated at temperatures above 220 degrees C. In some aspects, the coal is heated at temperatures above 225 degrees C. In some aspects, the coal is heated at temperatures above 230 degrees C. In some aspects, the coal is heated at temperatures above 235 degrees C. In some aspects, the coal is heated at temperatures above 240 degrees C. In some aspects, the coal is heated at temperatures above 250 degrees C. In some aspects, the coal is heated at temperatures above 260 degrees C. In some aspects, the coal is heated at temperatures above 265 degrees C. In some aspects, the coal is heated at temperatures above 270 degrees C. In some aspects, the coal is heated at temperatures above 275 degrees C. In some aspects, the coal is heated at temperatures above 280 degrees C. In some aspects, the coal is heated at temperatures above 285 degrees C. In some aspects, the coal is heated at temperatures above 290 degrees C. In some aspects, the coal is heated at temperatures above 295 degrees C. In some aspects, the coal is heated at temperatures above 300 degrees C. In some aspects, the coal is heated at temperatures above 305 degrees C. In some aspects, the coal is heated at temperatures above 310 degrees C. In some aspects, the coal is heated at temperatures above 315 degrees C. In some aspects, the coal is heated at temperatures above 330 degrees C. In some aspects, the coal is heated at temperatures above 335 degrees C. In some aspects, the coal is heated at temperatures above 330 degrees C. In some aspects, the coal is heated at temperatures above 335 degrees C. In some aspects, the coal is heated at temperatures above 340 degrees C. In some aspects, the coal is heated at temperatures above 350 degrees C.
In some aspects, the nuclear energy source may be used in the coal processing plant with one or more renewable electrical energy sources such as solar, wind, hydro, and wave, which are used to dry and beneficiate coal. In some aspects, the nuclear power source may be used to power the coal processing plant and non-carbon thermal energy sources such as solar thermal, geothermal, biomass combustion, and waste energy may be used to dry and beneficiate coal. In some aspect the nuclear energy source may be used to power the coal processing plant and one or more renewable electrical energy source and one or more non-carbon energy sources are used to dry and beneficiate coal.
In some aspects, the non-carbon thermal energy source may include using a geothermal power source.
In yet other aspects of the invention, the nuclear energy may be used to power the coal processing plant and a non-carbon thermal energy source may be produced from the combustion of biomass. Biomass is fuel generated from organic materials such as crops, lumber, manure/waste, compost, and biofuels such as ethanol or oils.
Electricity generated by nuclear power plants may be used as a direct source of electricity to supply power to the coal processing plant while other sources of energy such as electricity from renewables and non-carbon thermal sources may be used to dry and beneficiate coal to reduce water content. This effectively reduces the carbon footprint of coal burning facilities by supplying a clean source of energy to power the plant. Electricity generated by nuclear power plants may be used to supply power to the coal processing plant that uses any type of energy used in beneficiating processes such as electricity generated from any source, thermal energy from any source including fossil fuels, non-carbon energy, and waste energy.
In some aspects, the use of electricity generated by nuclear power plants may be used to power mechanical and electrical systems that beneficiate coal to reduce the water content of coal. In some aspects, the total water content of coal may be reduced by about 5%. In some aspects, the total water content of coal may be reduced by about 10%. In some aspects, the total water content of coal may be reduced by about 15%. In some aspects, the total water content of coal may be reduced by about 20%. In some aspects, the total water content of coal may be reduced by about 25%. In some aspects, the total water content of coal may be reduced by about 30%. In some aspects, the total water content of coal may be reduced by about 35%. In some aspects, the total water content of coal may be reduced by about 40%. In some aspects, the total water content of coal may be reduced by about 45%. In some aspects, the total water content of coal may be reduced by about 50%. In some aspects, the total water content of coal may be reduced by about 55%. In some aspects, the total water content of coal may be reduced by about 60%. In some aspects, the total water content of coal may be reduced by about 65%. In some aspects, the total water content of coal may be reduced by about 70%. In some aspects, the total water content of coal may be reduced by about 75%. In some aspects, the total water content of coal may be reduced by about 80%. In some aspects, the total water content of coal may be reduced by about 85%. In some aspects, the total water content of coal may be reduced by about 90%. In some aspects, the total water content of coal may be reduced by about 95%. In some aspects, the total water content of coal may be reduced by about 98%. In some aspects, the total water content of coal may be reduced by about 99%. In some aspects, the total water content of coal may be reduced by greater than 99%.
In some aspects, the total water content of coal may be reduced by about 1% to about 5%. In some aspects, the total water content of coal may be reduced by about 1% to about 10%. In some aspects, the total water content of coal may be reduced by about 5% to about 10%. In some aspects, the total water content of coal may be reduced by about 5% to about 15%. In some aspects, the total water content of coal may be reduced by about 10% to about 15%. In some aspects, the total water content of coal may be reduced by about 10% to about 20%. In some aspects, the total water content of coal may be reduced by about 15% to about 20%. In some aspects, the total water content of coal may be reduced by about 15% to about 25%. In some aspects, the total water content of coal may be reduced by about 20% to about 25%. In some aspects, the total water content of coal may be reduced by about 20% to about 30%. In some aspects, the total water content of coal may be reduced by about 25% to about 30%. In some aspects, the total water content of coal may be reduced by about 25% to about 35%. In some aspects, the total water content of coal may be reduced by about 30% to about 35%. In some aspects, the total water content of coal may be reduced by about 30% to about 40%. In some aspects, the total water content of coal may be reduced by about 35% to about 40%. In some aspects, the total water content of coal may be reduced by about 35% to about 45%. In some aspects, the total water content of coal may be reduced by about 40% to about 45%. In some aspects, the total water content of coal may be reduced by about 40% to about 50%. In some aspects, the total water content of coal may be reduced by about 45% to about 50%. In some aspects, the total water content of coal may be reduced by about 45% to about 55%. In some aspects, the total water content of coal may be reduced by about 50% to about 55%. In some aspects, the total water content of coal may be reduced by about 50% to about 60%. In some aspects, the total water content of coal may be reduced by about 55% to about 60%. In some aspects, the total water content of coal may be reduced by about 55% to about 65%. In some aspects, the total water content of coal may be reduced by about 60% to about 65%. In some aspects, the total water content of coal may be reduced by about 60% to about 70%. In some aspects, the total water content of coal may be reduced by about 65% to about 70%. In some aspects, the total water content of coal may be reduced by about 65% to about 75%. In some aspects, the total water content of coal may be reduced by about 70% to about 75%. In some aspects, the total water content of coal may be reduced by about 70% to about 80%. In some aspects, the total water content of coal may be reduced by about 75% to about 80%. In some aspects, the total water content of coal may be reduced by about 75% to about 85%. In some aspects, the total water content of coal may be reduced by about 80% to about 85%. In some aspects, the total water content of coal may be reduced by about 80% to about 90%. In some aspects, the total water content of coal may be reduced by about 85% to about 90%. In some aspects, the total water content of coal may be reduced by about 85% to about 95%. In some aspects, the total water content of coal may be reduced by about 90% to about 95%. In some aspects, the total water content of coal may be reduced by about 90% to about 98%. In some aspects, the total water content of coal may be reduced by about 95% to about 98%. In some aspects, the total water content of coal may be reduced by about 90% to about 99%. In some aspects, the total water content of coal may be reduced by about 95% to about 99%.
In some aspects, beneficiating coal to reduce water content results in an increase in the stored energy content of the coal thereby enhancing the beneficiation process. In some aspects, the stored energy content may be increased greater than 10%. In some aspects, the stored energy content may be increased greater than 20%. In some aspects, the stored energy content may be increased greater than 30%. In some aspects, the stored energy content may be increased greater than 40%. In some aspects, the stored energy content may be increased greater than 50%. In some aspects, the stored energy content may be increased greater than 60%. In some aspects, the stored energy content may be increased greater than 70%. In some aspects, the stored energy content may be increased greater than 80%. In some aspects, the stored energy content may be increased greater than 90%. In some aspects, the stored energy content may be increased greater than 100%. In some aspects, the stored energy content may be increased greater than 110%. In some aspects, the stored energy content may be increased greater than 120%. In some aspects, the stored energy content may be increased greater than 130%. In some aspects, the stored energy content may be increased greater than 140%. In some aspects, the stored energy content may be increased greater than 150%. In some aspects, the stored energy content may be increased greater than 160%. In some aspects, the stored energy content may be increased greater than 170%. In some aspects, the stored energy content may be increased greater than 180%. In some aspects, the stored energy content may be increased greater than 190%. In some aspects, the stored energy content may be increased greater than 200%. In some aspects, the coal beneficiation process comprises mechanical water reduction.
In some aspects, electricity generated by a nuclear power plant is supplied to a coal-preparation plant located at a coal mine. In some aspects, the coal processing plant may be located at a coal transportation terminal. In some aspects, the coal transportation terminal comprises a ship. In some aspects, the coal transportation terminal comprises a barge. In some aspects, the coal transportation terminal comprises a rail. In some aspects, the coal transportation terminal comprises a truck.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration showing one configuration of the invention.

DETAILED DESCRIPTION OF THE INVENTION

There are a number of known coal beneficiation processes in the art, e.g. those as described in U.S. Pat. No. 3,999,958; U.S. Pat. No. 4,252,639; U.S. Pat. No. 4,397,248; U.S. Pat. No. 4,412,842; U.S. Pat. No. 4,632,750; U.S. Pat. No. 4,702,824; U.S. Pat. No. 6,632,258; U.S. Pat. No. 7,901,473; U.S. Pat. No. 8,585,788; U.S. Pat. No. 8,579,998; U.S. Pat. No. 8,647,400; and U.S. Pat. No. 8,925,729, the disclosure of each of which is incorporated by reference in their entirety. However, each of these processes has inherent limitations in that the coal beneficiation processes described therein are not conducted at a plant that is at least partially powered by electricity generated from a nuclear energy source. As a consequence the net overall environmental impact of those coal beneficiation processes is limited, principally that those coal beneficiation processes require an enormous amount of energy obtained from carbon emitting energy sources. Thus, even if the end result is a more energy-dense coal product, the net benefit on environmental impact is not reduced or minimized in many circumstances.
The present invention provides an attractive means to reduce the carbon footprint of coal processing plants by integrating electricity generated by a nuclear energy source to reduce the overall environmental impact and to provide a consistent non-carbon energy source to the coal processing plant that beneficiates coal. Using electricity generated by a nuclear energy source to power the coal processing plant decreases the use of fossil-fuel fired energy sources to power the coal processing plant. Using a nuclear energy source to power a plant that beneficiates and dries coal has a number of distinct potential advantages over the prior art.
Some of the advantages are as follows. Using electricity generated by a nuclear energy source to power a coal processing plant increases the energy density of the coal and thus reduces the volume of coal necessary to operate the coal-fired electrical generating plant. Using electricity generated by a nuclear energy source may also be used to operate mechanical and electrical equipment used in coal beneficiation, such as coal crushers, pulverizers, compression device and aerodynamic forces to remove moisture from coal allows for large-scale storage of low-carbon electrical energy with subsequent generation of dispatchable energy. In many circumstances, the coal may be further dried by renewable sources and/or other non-carbon thermal energy sources further reducing the carbon footprint of the coal processing plant. Advantageously, this allows the nuclear plant to operate at constant load conditions even as more and more intermittent renewable sources are added to the grid. By helping the nuclear power plant continue to operate as the generation mix on the grid changes, it preserves reduced carbon emissions and eliminates carbon emissions from fossil sources needed to replace any nuclear power plant that is decommissioned. When nuclear energy is used to power the coal processing plant or used to supply electricity to mechanical equipment used to beneficiate coal, the resulting beneficiated coal may be capable of being produced in an amount to produce hundreds to thousands of megawatts (MWs) of electrical power. For example, beneficiated coal may be produced in an amount sufficient to power a 5 MW rated plant, a 10 MW rated plant, a 25 MW rated plant, a 50 MW rated plant, a 75 MW rated plant, a 100 MW rated plant, a 125 MW rated plant, a 150 MW rated plant, a 175 MW rated plant, a 200 MW rated plant, a 225 MW rated plant, a 250 MW rated plant, a 275 MW rated plant, a 300 MW rated plant, a 325 MW rated plant, a 350 MW rated plant, a 375 MW rated plant, a 400 MW rated plant, a 425 MW rated plant, a 450 MW rated plant, a 475 MW rated plant, a 500 MW rated plant, a 525 MW rated plant, a 550 MW rated plant, a 575 MW rated plant, a 600 MW rated plant, a 625 MW rated plant, a 650 MW rated plant, a 675 MW rated plant, a 700 MW rated plant, a 725 MW rated plant, a 750 MW rated plant, a 775 MW rated plant, a 800 MW rated plant, a 825 MW rated plant, a 825 MW rated plant, a 875 MW rated plant, a 900 MW rated plant, a 925 MW rated plant, a 950 MW rated plant, a 975 MW rated plant, a 1,000 MW rated plant, or plants rated above 1,000 MW, and any intervening ranges therein.
Coal beneficiated with mechanical systems whose power source is electricity generated by nuclear power may be further dried using renewable electrical energy such as such as solar, wind, hydro, and wave energy; non-carbon thermal energy sources, such as solar, geothermal, biomass combustion, and waste energy; or both. The energy stored in such beneficiated coal may be stored for a significant period of time, for several months up to a year or longer, as opposed to many other storage devices. For example, beneficiated coal may have a shelf life of at least 1 month, at least 2 months, at least 3 months, at least 4 months, at least 5 months, at least 6 months, at least 7 months, at least 8 months, at least 9 months, at least 10 months, at least 11 months, at least 12 months, at least 13 months, at least 14 months, at least 15 months, at least 16 months, at least 17 months, at least 18 months, at least 19 months, at least 20 months, at least 21 months, at least 22 months, at least 23 months, at least 24 months, or greater than 24 months, and any intervening ranges therein.
Referring now to FIG. 1 one possible configuration of the invention is illustrated. Raw coal (41) is delivered to the coal processing plant (42) which dries and beneficiates the coal with a higher energy content (44) which is then taken to a power plant by a unit of transportation (45) where it is burned to make electricity. Electricity to operate equipment in the coal processing plant (42) is provided by a nuclear power plant (43). The coal drying/beneficiation plant (42) also requires an external source of thermal energy or heat. In this configuration, the thermal energy is provided by a solar thermal system in which water or a working fluid is exposed to the sun in panels (47), which heats the fluid. The heated fluid is then stored in an insulated vessel (50) to store the thermal energy. The heated working fluid is then sent to a heat exchanger (49), which heats air, liquid, or steam, which is then used in the coal processing plant. A gas-fired boiler (46) is used to produce steam or heated working fluid to supplement the thermal energy from the solar thermal system. The temperatures, pressures, and flow rates from all of the components are measured electronically and sent to an automatic controller (48), which balances the system and insures that the proper quantity and quality of thermal energy is delivered to the coal processing plant.

Example I

Assume a base case of a 500 MW coal-fired power plant with a heat rate of 10,500 BTU/kWh burning 2.2 MT/yr of subbituminous coal from the Powder River Basin with a moisture content of 26% and an energy content of 8900 BTU/lb. A coal beneficiating plant treats all of the 2.2 MT/yr of the coal prior to combustion, in the power plant, reducing the moisture content to 13% and thereby increasing the energy content of the treated coal to 9,900 BTU/lb. In this example, all of the electricity needed to dry the coal, 220,000 MW-hr/yr, is produced by the coal-fired power plant. When the coal is burned in the power plant to make electricity on demand, the combination of synergistic effects and increased generation efficiency results in reducing the emissions of carbon dioxide from the plant. However, the reduction in emissions is offset somewhat by an increase in carbon dioxide emissions associated with electricity used in the coal drying process. By using the system and methods in accordance with the invention and providing the 220,000 MW-hr/year of electricity from carbon-free nuclear power, a reduction of 289,000 tons of carbon dioxide per year is achieved.
Not only does the nuclear energy source reduce the carbon footprint of the coal processing plant but combining with renewable electrical energy sources and non-carbon thermal sources to beneficiate coal disconnects the timing of the energy stored in the coal during beneficiation from the timing of the use of the stored energy to satisfy customer demand. This is especially relevant in the case of non-carbon thermal energy sources such as solar thermal, which is reliant on natural conditions beyond human intervention. The storage of thermal energy in beneficiated coal is highly efficient because most of the thermal energy stored from the non-carbon sources is recovered when the coal is burned to produce power. This is the case no matter which beneficiating processes are used. Further, it allows the beneficiation facility to be located at the source of renewable electrical energy and/or non-carbon thermal energy generation and the beneficiated coal can be used at another location without the need for transmission lines that are expensive and difficult to permit across private property, state and national borders. It also allows the nuclear power plant to operate at constant load conditions instead of having to deal with the variability created by intermittent renewable sources as they are added to the grid. Moreover, nuclear power can provide a constant source of energy to the coal processing plant for beneficiation processes conducted therein.
In addition, coal beneficiated in a coal processing plant powered by nuclear energy can be shipped across oceans to other countries that are not possible to reach by transmission lines because of cost and practical limitations. The beneficiated coal represents stored energy that can be transported by truck, rail, barge, or ship across a continent, or around the world, to meet consumer demand for power.
A coal processing plant powered by nuclear energy may also beneficiate coal using renewable sources such as solar, wind, hydro, and wave energy; non-carbon thermal energy sources, such as solar, geothermal, biomass combustion and waste energy, or both. The invention may also be used in conjunction with both renewable electrical energy sources and non-carbon thermal energy sources when those sources are used in beneficiating coal. Beneficiation can occur close to the site where the nuclear energy is produced, where the coal is mined, at power plants where the coal is converted into energy or at transportation terminals that feed into multiple different plants. Alternatively, the coal beneficiation process can occur at all of the foregoing sites with or without further beneficiation of the coal. This means that at least the following combinations are possible. The nuclear power plant, the coal beneficiation process, the coal-fired electrical generating plant, and the coal mining can be at four different sites. The nuclear power plant, the coal beneficiation process, the coal-fired electrical generating plant, and the coal mining can be all at the same site. The coal beneficiation process and the coal mining can all be at the same site, with the nuclear power plant and coal-fired electrical generating plant at a different site. The coal beneficiation process can be at one site, and the nuclear power plant and the coal-fired electrical generating plant and the coal mining at a different site or sites. Those of skill in the art will appreciate that numerous combinations are possible. Those of skill in the art will also appreciate that supplemental beneficiation of the coal may occur at any one of the sites listed above. These combinations may be further expanded to one or more additional sites.
In those embodiments where the coal beneficiation process is integrated with the operation of a coal-fired electrical generating plant, i.e. located at the same site as the coal coal-fired electrical generating plant, the coal beneficiation process can be integrated into the operation of the coal-fired electrical generating plant in order to further increase its operational efficiency. For example, electricity generated by a nuclear power plant may be used to provide power to the coal processing plant and may be used to power the equipment used to remove moisture from coal. The electricity from the nuclear power plant could be supplemented with electricity generated from renewable sources such as solar, wind, hydro, and wave energy; non-carbon thermal energy sources, such as solar, geothermal, biomass combustion, and waste energy; or both renewable electrical energy sources and non-carbon thermal sources to beneficiate coal.
Providing electricity generated from nuclear energy to coal processing plants is compatible and complementary to the other means of reducing carbon emissions from coal-fired electrical generating plants including ultra- and supercritical plants and CCS technologies. By using electricity to power the coal processing plant and/or the mechanical systems that reduce the amount of moisture in the coal in conjunction with electricity from renewable sources such as solar, wind, hydro, and wave energy and/or with non-carbon thermal energy sources, such as solar, geothermal, biomass combustion, and waste energy or both, will reduce the amount of coal being burned which will improve the operation of several plant systems resulting in reducing the parasitic power needed to run the plant. For example, it will lower the amount of pollutants and the volume of flue gas to be treated by air pollution control (APC) equipment. The reduced amount of coal will reduce the electrical power required to pulverize the coal. The resulting lower volume of combustion gases will also reduce the power required by the fans to move the gases. This will have an added benefit of reducing the pressure difference between the inside of the duct and the outside air resulting in lower in-leakage of air, which reduces the efficiency of the plants. All of these reductions in parasitic energy result in a decrease in the amount of CO₂produced per unit of net electrical power generated by the plant. An additional benefit may be the generation of greater amounts of electricity at a plant that was originally designed for a higher heat content coal that has to operate at lower generation load levels on the non-dried coal. This will allow the power company to optimize how much power is generated from a lower CO₂emitting plant. The coal which is subject to these processes may be any type of coal, including peat coal, lignite coal, sub-bituminous coal, bituminous coal, and anthracite, although one of ordinary skill in the art will recognize that coal with higher water content such as sub-bituminous coal will benefit more from beneficiation than lower water content coal such as bituminous coal.
In some embodiments, electricity generated by a nuclear energy source is used to power a coal processing plant utilizing a non-carbon thermal energy source for beneficiating coal. The non-carbon thermal energy source may comprise a solar thermal energy source. Solar thermal energy has several distinct advantages and drawbacks. Solar thermal energy is totally non-carbon, and under certain conditions, such as those found in the American Southwest, are capable of generating high degrees of heat for the beneficiation of coal. One key advantage of solar thermal energy is that it is less expensive and more efficient than directly converting solar energy to electricity and then converting the electricity to thermal energy to burn coal. However, solar thermal energy systems are diurnal and only capable of generating heat when exposed to sunlight, thus their efficiency is limited. Thus, integrating solar thermal energy enhances coal beneficiation and allows for systems where any energy may be used to power the coal beneficiation process to provide a product that is capable of long-term storage and provide consistent output.
The non-carbon thermal energy sources reduce the need to combust fossil fuels to produce thermal energy to remove moisture thereby reducing the carbon footprint of the coal treatment plant. Other sources of non-carbon thermal energy include geothermal, biomass combustion, and waste energy.
In some embodiments, electricity generated by a nuclear energy source is used to supplement the electricity from renewable electrical energy sources to power a coal processing plant. The renewable electrical energy source may comprise a hydroelectric source. Other sources of renewable electrical energy include solar, wind, and wave energy.
The coal beneficiation process typically comprises reduction of the total water content of coal. The reduction of the total water content may be performed by mechanical equipment and systems powered by electricity generated by a nuclear power source. Water is contained in coal in a number of different forms such as free water, bound water, and non-freezing water which are all included in the total water content of the coal. In this invention, the reduction of coal moisture is not bound by which type of moisture is impacted, only that overall reduction of any water is reduced. The water content reduction can be less than about 1%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 98%, about 99%, or greater than about 99%, and any intervening ranges therein. As defined herein, the water content reduction as measured by percent (%) water reduction is measured relative to the total water content of coal before and after beneficiation.
The coal beneficiation process increases the stored energy content of the coal, typically corresponding to reduction of the total water content of the coal. The stored energy content is typically, although not necessarily, measured in BTUs. The stored energy content may be increased by about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 110%, about 120%, about 130%, about 140%, about 150%, about 160%, about 170%, about 180%, about 190%, about 200%, or greater than about 200%, and any intervening ranges therein.
Mechanical systems used in coal beneficiation processes may be powered by electricity generated by a nuclear energy source. Typically, the coal is crushed into macerals, optionally washed, compacted, dried, and then briquetted although the crushing and washing stage may occur in different order. The crushing can occur by a number of means known in the art, including, but not limited to, through mechanical force, shredding, tearing, or through sonication/vibrations. At this stage, the coal is typically (but not necessarily) low ranking coal, such as lignite coal. Before or, ideally, after being pulverized or crushed into macerals, the macerals are optionally subjected to a washing step, i.e. coal washing. Coal washing is a process known in the art by which the coal is separated based on difference in specific gravity and impurities such as shale or sand, such that the impurities are “washed” out and what is left behind is purer coal with a higher calorific value. The coal washing can occur via a jig or some other gravity separation method, such as a dense medium bath or a dense medium cyclone. A number of dense medium baths exist including but not limited to teska bath, daniels bath, leebar bath, drewboy bath, barvoys bath, chance cone, wemco drums, tromp shallow bath, and combinations thereof. After the optional washing, the macerals are typically compacted, although not necessarily.
The coal processing plant may also use supplemental renewable electrical energy sources, thermal energy from non-carbon sources or both to reduce the amount of moisture in the coal. When nuclear energy is used to operate the coal processing plant and provide electricity to mechanical systems along with electricity from renewable sources and/or thermal energy sources, the total stored energy content of the coal as measured in the total energy content of the coal (e.g. in BTUs) per unit mass (e.g. gram or kilogram) of the coal is increased while the carbon footprint of the coal processing plant is greatly reduced. Furthermore, in such embodiments, there is little to no oxidation or volatilization of the coal, thus leaving little to no harmful gasses or emissions from the beneficiation processes, minimizing environmental impact.
As used herein and in the appended claims, the singular forms “a”, “and” and “the” include plural references unless the context clearly dictates otherwise.
Where a value of ranges is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges which may independently be included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either both of those included limits are also included in the invention.
The term “about” refers to a range of values which would not be considered by a person of ordinary skill in the art as substantially different from the baseline values. For example, the term “about” may refer to a value that is within 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value, as well as values intervening such stated values.
Publications disclosed herein are provided solely for their disclosure prior to the filing date of the present invention. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.
Each of the applications and patents cited in this text, as well as each document or reference, patent or non-patent literature, cited in each of the applications and patents (including during the prosecution of each issued patent; “application cited documents”), and each of the PCT and foreign applications or patents corresponding to and/or claiming priority from any of these applications and patents, and each of the documents cited or referenced in each of the application cited documents, are hereby expressly incorporated herein by reference in their entirety. More generally, documents or references are cited in this text, either in a Reference List before the claims; or in the text itself; and, each of these documents or references (“herein-cited references”), as well as each document or reference cited in each of the herein-cited references (including any manufacturer's specifications, instructions, etc.), is hereby expressly incorporated herein by reference.

Claims

1. A system to reduce the emissions of carbon dioxide associated with coal fired power plants by using electricity from a nuclear power plant to power a coal processing plant that reduces the moisture content of coal resulting in an increased energy density beneficiated coal comprising:

a source of electricity from a nuclear power plant;

a coal processing plant configured to reduce the moisture content of the coal by a beneficiation process to produce an increased energy density coal; and

a coal-fired power plant configured to convert the increased energy density coal to electricity on demand at a higher efficiency with reduced emissions of carbon dioxide.

2. (canceled)

3. The system of claim 1 wherein the coal processing plant is configured to utilize energy selected from microwave energy and mechanical energy including compression to reduce the moisture content of the coal.

4. The system of claim 1 further comprising electricity from a renewable electrical energy source selected from hydroelectric power, solar power, wind power, and wave power, and combinations thereof configured to supplement the electricity generated by the source of nuclear energy for beneficiating and drying the coal.

5. (canceled)

6. The system of claim 1 further comprising a supplemental source of thermal energy selected from the combustion of fossil fuels, waste heat, and a source of non-carbon thermal energy configured to be used in the beneficiation process to supplement the source of electricity from the nuclear power plant supplied to the coal processing plant.

7. (canceled)

8. (canceled)

9. (canceled)

10. The system of claim 6 wherein the non-carbon thermal energy source is selected from a solar thermal energy source, a geothermal energy source, a biomass energy source and combinations of the foregoing.

11. The system of claim 1 wherein a location of the coal processing plant is selected from a coal mine, a coal transportation terminal including ships, barges, rail and trucks, a coal-fired power plant, a same site as the non-carbon thermal energy source and combinations of the foregoing.

12. (canceled)

13. The system of claim 1 wherein the coal processing plant is integrated with a coal-fired power plant and shares use of coal handling, coal crushing and coal conveying equipment.

14. The system of claim 1 wherein said increased energy density coal is configured to be stored, transported and later combusted to produce said electricity on demand.

15. The system of claim 6 wherein the supplemental thermal energy source is configured to preheat the coal prior to processing.

16. A system to store electricity generated by a nuclear power plant by using the electricity to power a coal processing plant to decrease the moisture content of coal resulting in an increased energy density beneficiated coal that can be later combusted to produce electricity on demand comprising:

electrical energy from a nuclear power plant;

a coal preparation plant, wherein the electrical energy from the nuclear power plant is stored in an increased energy density beneficiated coal; and

a coal-fired power plant configured to recover the stored energy by combusting the coal to produce electricity on demand at an increased efficiency.

17. (canceled)

18. The system of claim 16 wherein the coal processing plant is configured to use energy selected from microwave energy and mechanical energy including compression to decrease the moisture content of the coal.

19. The system of claim 16 further comprising a renewable electrical energy source selected from hydroelectric power, solar power, wind power, and wave power, and combinations thereof for supplementing the electricity generated by the source of nuclear energy to beneficiate and dry the coal.

20. (canceled)

21. The system of claim 16 further comprising a source of thermal energy selected from a combustion of fossil fuels, waste heat, a non-carbon thermal energy source and combinations of the foregoing to supplement the electricity generated by the source of nuclear energy to beneficiate and dry the coal.

22. (canceled)

23. (canceled)

24. (canceled)

25. The system of claim 21 wherein the non-carbon thermal energy source is selected from a solar thermal energy source, a geothermal energy source, a biomass energy source and combinations of the foregoing.

26. The system of claim 16 wherein a location of the coal processing plant is selected from a coal mine, a coal transportation terminal including ships, barges, rail, and trucks, a coal-fired power plant, a same site as the non-carbon thermal energy source and combinations of the foregoing.

27. (canceled)

28. The system of claim 16 wherein the coal processing plant is integrated with a coal-fired power plant and shares use of coal handling, coal crushing and coal conveying equipment.

29. The system of claim 16 wherein said increased energy density beneficiated coal is configured to be stored, transported and later combusted to produce said electricity on demand.

30. The system of claim 21 wherein the source of thermal energy source is configured to preheat the coal prior to processing.