THERMAL HYDROGEN

Abstract

Methods and systems for emissions free dispatchable power supply, emissions free chemical energy storage, and emissions free chemical energy distribution are disclosed. Methods include providing water and/or carbon dioxide to an electrolyser; providing electricity from a regional electrical power grid to the electrolyser for electrolysis of the water and/or carbon dioxide to produce oxygen; and providing the oxygen from the electrolyser to a hydrocarbon oxidation device for the oxidation of a hydrocarbon.

Claims

1. A method of operating a system comprising an electrical power plant, an electrolyser connected to a regional electrical power grid, and a hydrocarbon oxidation device, comprising: providing water and/or carbon dioxide to the electrolyser; providing electricity from the regional electrical power grid to the electrolyser for electrolysis of the water and/or carbon dioxide to produce oxygen; and providing the oxygen from the electrolyser to the hydrocarbon oxidation device for the oxidation of a hydrocarbon.

2. The method of claim 1 wherein the electrical power plant has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is less than two times the regional wholesale cost of natural gas.

3. The method of claim 2 wherein the electrical power plant has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is less than three times the regional wholesale cost of natural gas.

4. The method of claim 1 wherein the electrolyser has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is more than one and a half times the regional wholesale cost of natural gas.

5. The method of claim 4 wherein the electrolyser has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is more than two times the regional wholesale cost of natural gas.

6. The method of claim 1, wherein heat from the electrical power plant is provided to the electrolyser for heat-assisted electrolysis.

7. The method of claim 1, wherein electricity from the electrical power plant is provided to the electrolyser when supply of electricity from the electrical power plant exceeds other electricity demand.

8. The method of claim 1, wherein the hydrocarbon oxidation device at least partially oxidizes the hydrocarbon to produce hydrogen or syngas.

9. The method of claim 8, comprising providing the hydrogen or syngas to a solid oxide fuel cell.

10. The method of claim 8, wherein the hydrocarbon oxidation device is an auto-thermal reformer or hydrocarbon gasifier.

11. The method of claim 10, wherein the hydrocarbon is methane.

12. The method of claim 10, wherein the hydrocarbon is coal or biomass.

13. The method of claim 1, comprising providing the oxygen to an oxy-fueled power plant.

14. The method of claim 13, wherein the oxy-fueled power plant is an Allam cycle power plant.

15. The method of claim 1, wherein the electrical power plant is a nuclear power plant, a solar thermal or CPV power plant, or geothermal power plant.

16. The method of claim 1, wherein the electrical power plant has an electricity generating capacity of at least 50 megawatts.

17. The method of claim 1, wherein the electrical power plant has an electricity generating capacity of at least 100 megawatts.

18. A system comprising: an air separation unit, a hydrocarbon reformer, and a Haber-Bosch process unit; wherein the air separation unit provides nitrogen to the Haber-Bosch process unit; wherein the hydrocarbon reformer unit provides hydrogen to the Haber-Bosch process unit.

19. The system of claim 18 comprising a methanol reformer; wherein the hydrocarbon reformer provides hydrogen and/or carbon monoxide to the methanol reformer.

20. The system of claim 19 comprising a water gas shift reaction providing hydrogen and/or carbon monoxide to the methanol reformer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0093] FIG. 1 illustrates the broadest view of the Thermal Hydrogen energy systems and how all three Thermal Hydrogen concepts, supply, storage, and distribution, are related.

[0094] FIG. 2 illustrates an embodiment of the Thermal Hydrogen supply system using heat assisted electrolysis and a heat engine in order to provide the effect of dispatchable electricity supply as well as a supply of chemical energy carriers and oxygen.

[0095] FIG. 3 illustrates an oxyfueled embodiment of the Thermal Hydrogen system which shows hydrocarbons as the emissions free fuel which may dispatch an oxyfueled turbine based upon the price of the grid.

[0096] FIG. 4 illustrates a Thermal Hydrogen storage system.

[0097] FIG. 5 illustrates a Thermal Hydrogen distribution system.

[0098] FIG. 6 illustrates a method and system during a period of excess electricity supply on the grid.

[0099] FIG. 7 illustrates a method and system during a period of deficient electricity supply on the grid.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0100] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. One embodiment of the invention is shown in great detail, although it will be apparent to those skilled in the relevant art that some features that are not relevant to the present invention may not be shown for the sake of clarity.

[0101] The essence of meeting energy services is providing a distribution system from supply to demand. Due to the incongruence of supply and demand, both temporally and spatially, it is necessary to engineer a distribution system which satisfies both dimensions.

[0102] Hydrocarbon energy suppliers and carriers have served the purposed of solving both temporal and spatial problems for over a century. Hydrocarbons were stored millions of years ago, and given that carbon is the most versatile element in the universe, it should be no surprise that hydrocarbons are abundant and come in different phases: as a solid, gas, or liquid.

[0103] Between the ability to store solid hydrocarbons at power plants, or pipe gaseous/liquid hydrocarbons to power plants, or pump liquid hydrocarbons to portable power plants, the task of meeting energy services is met in both dimensionstemporal (time) and spatial (space).

[0104] The challenge of decarbonization is overcoming the temporal and spatial and temporal challenges of distribution without using the versatility of hydrocarbon atmospheric oxidationor paying the price of gas separation through Carbon Capture and Sequestration.

[0105] The energy system proposed here suggests that underutilized capacity is inevitable somewhere in the system at some time simply due to the lack of coincidence between supply and electricity demand on temporal basis.

[0106] Secondly, Thermal Hydrogen suggests that inefficiency is inevitable somewhere in the system at some time simply due to thermodynamics. Given that some energy supplier will utilize a heat engine, significant energy losses are inevitable. If Carnot is to be avoided, for instance by using an electrolyser/reformer and then using a fuel cell, energy is lost due to the extra processes involved.

[0107] The Thermal Hydrogen system acknowledges that decarbonization implies increasing capital intensityeither through use of fewer hydrocarbons or by use of Carbon Capture and Sequestration. Some of this excess capital intensity will be in the form of heatsuch as nuclear decay, excess solar energy, geothermal energy, etc.

[0108] However, increasing capital intensity does not necessarily mean increasing costs. Renewables and fossil fuels may have the same levelized costs. However, if the energy service at hand is dispatchable electricity, that is a service not yet offered by cheap renewables. The key is to take advantage of more capital intense energy suppliers without taking on a problem of low utilization or inefficiency.

[0109] Rather than trying to engineer an energy system without any waste energy or excess capacity, the Thermal Hydrogen system simply seeks to improve upon the current system. With the current fossil based system, the cost of excessive capital intensity is in the arena of $1,000/kW.

[0110] Furthermore, with the current fossil based system, the cost of inefficiency is in the heat engines, meaning that about half the heat or more is lost in the condenser (Carnot losses). Finally, fossils currently use steam cycles for both electricity and hydrogen production. This provides additional room for improvement as pure oxygen fueled cycles do not require steam as an intermediate thermal medium.

[0111] Therefore, the current system can be improved upon by providing the effect of dispatchable capacity through dispatchable supply as well as dispatchable demand. The devices which will be underutilized in order to provide the effect all have costs approximately half of a heat engine. Therefore, the temporal problem of distribution, underutilization of capacity, is absorbed by something less capital intensean electrolyserrather than by something that is more capital intensea nuclear reactor.

[0112] So, while additional steps are required by these process, each of these steps is less capital intensive and more energy efficient. It is possible for these steps to become more energy efficient because they use multiple, efficient steps rather than fewer, less efficient steps. Electrolytes are used instead of pneumatics, allowing an escape from Carnot losses of heat engine.

[0113] One may argue that these additional steps will result in heat loss at the point of supply, storage, or distribution due to the inevitable nature of chemical energy carriers to give off waste heat due to chemical reduction/compression/condensing. However, the Thermal Hydrogen pairs heat demand with excess heat at every point of the process: supply, storage, and distribution. Therefore, minimal heat is lost to the atmosphere.

[0114] Thus, the energy system does not completely rid emissions free energy of either capital intensity or inefficiency. However, underutilized capacity is limited to $1000/kW and energy losses are limited to Carnot or less.

[0115] FIG. 1 illustrates all three of the Thermal Hydrogen energy systems with the broadest view possible. From the left side of the figure to the right, the supply, storage, and distribution systems of Thermal Hydrogen are shown. The supply system is shown in more detail in FIGS. 2 and 3, the storage system is shown in more detail in FIG. 4, and the distribution system is shown in more detail in FIG. 5.

[0116] The Thermal Hydrogen supply system consists of three different technologies an electrical power plant (1), a heat source (2), and an electrolyser (3). These three technologies work together to provide the effect of emissions free, dispatchable electricity without underutilized capital-intensive capacity.

[0117] The heat source (2), which typically has by far the highest capital cost, is intended to maintain full utilization regardless of demand for electricity. During times of deficient electricity supply on the grid, the power plant (1) produces electricity. The power plant may be fueled by the heat source (2), or by the hydrocarbon and O.sub.2 (4).

[0118] These systems are shown here on the same power block, but these power plants may not be co-located to take advantage of the portability of oxygen and hydrocarbons which may garner higher electricity prices if piped towards electricity transmission constraints.

[0119] During times of excessive electricity supply on the grid, the heat source directs its heat towards the electrolyser (3). The electrolyser provides the service of dispatchable demand by purchasing electricity from the grid. However, heat is not necessarily lost during this process if heat-assisted electrolysis is utilized due to the endothermic nature of electrolysis.

[0120] Therefore, the supply system accomplishes similar efficiency loss as a heat engine, but enables the heat source to provide the effect of dispatchable supply without underutilization of capital-intensive capacity.

[0121] The products of electrolysis are piped either directly to demand, or towards the Thermal Hydrogen Storage system as shown in the figure. Electrolysis may produce either H.sub.2 or CO (carbon monoxide). If necessary, this is the only time gases are piped in the entire system (with the exception of ammonia delivery). All other chemicals can be distributed as pumpable fluids: oxygen, ammonia, methanol, and CO.sub.2.

[0122] Because of the pumpability of the chemical energy carriers utilized, the Thermal Hydrogen storage system can be located either close to supply or closer to distribution. If the facility is located closer to supply, the advantage is less syngas and oxygen piping. The former requires a compressor whereas the latter introduces a risk due to the flammability of oxygen. An embodiment of the pipelines of O.sub.2 (6) and CO.sub.2 (7) provides insulation to the oxygen by wrapping the oxygen in a chemical which retards combustion.

[0123] If oxygen piping hurdles can be overcome, the Thermal Hydrogen Storage facility can be located closer to demand. In this instance, hydrogen could be distributed rather than hydrogen carriers with the minimum distance required.

[0124] The Thermal Hydrogen storage system converts the products of electrolysis and hydrocarbons, to pumpable, distributable chemical energy carriers. This energy system has the least capital-intensive components of the whole system and also features the least heat losses of the energy system. This system could be thought of as the modern equivalent of an oil refinerythrough efficiency and low capital intensity, it has a minor impact on system costs.

[0125] The waste heat of all exothermic processes (WGS, Haber-Bosch, methanol reforming) is utilized to assist reforming. Compressing of any gases to liquid is prevented by using the waste cooling from the air separation unit (8). Ammonia (9), methanol, and oxygen are all stored as cold liquids from the waste cooling of the air separation unit. After achieving liquid form, these chemicals are pumped to distribution pressure, and before leaving the system their cooling is used to pre-cool the incoming air to the ASU.

[0126] The fluids are then piped to the Thermal Hydrogen distribution system. At the distribution system, ammonia is distributed to applications where atmospheric combustion is desired (10). The methanol is piped to solid oxide fuel cells where the carbonated water is recollected and then piped back (11).

[0127] As shown from this very broad view, each component of the energy system is mutually reinforcing. The effect of dispatchable electricity is provided without idling any capital intense capacity. Energy is stored and distributed to load as a pumpable fluid without any single significant process causing substantial heat loss. Therefore, the system offers a balance of capital intensity and energy efficiency similar to that of the modern energy system which relies on dispatchable heat engines.

[0128] FIG. 2 illustrates the first embodiment of the Thermal Hydrogen supply system. It consists of a heat engine (12), a heat source (13), and heat assisted electrolysis (14). Not shown in the figure is the use of the oxygen (15), and this will be discussed in FIG. 4 below.

[0129] This combination of devices in operated in a way to provide the effect of dispatchable supply but without underutilizing the most capital-intensive component.

[0130] This figure is intended to be illustrative of the energy balance occurring with different operation modes. The system on the left, where the turbine is engaged, has two units of heat energy input as indicted by the arrows. Assuming this is a high temperature source, this engine would produce one unit of electricity and lose one unit of heat to the atmosphere.

[0131] The figure on the right side shows the heat source being re-directed towards the electrolyser. Then, electricity input from the grid augments this heat supply. The electrolyser is 75% efficient whereas the turbine is only 50% efficient. However, both systems result in the same amount of heat going to the atmosphere, and the same amount of net energy being producedeither one unit of electricity or one net unit of chemical energy.

[0132] Given that the net production of each pathway is the same, it's a matter of the value of the chemicals vs. the value of electricity. However, the production of oxygen increases the value of electrolysis. The value of oxygen provides an additional revenue stream for electrolysis. Between the efficiency of electrolysis and the value of chemical energy carriers and oxygen, the electrolyser can justify its capital costs.

[0133] FIG. 3 illustrates the oxyfuel embodiment of the Thermal Hydrogen supply system. It consists of an electrolyser (16), turbine (17), and some sort of partial oxidation (18) process which produces chemical energy carriers.

[0134] Whereas FIG. 2 showed the approximate energy intensity of each process by using a proportional number of arrows, this system attempts to convey the oxygen intensity of each hydrocarbon process (19) and (20).

[0135] As the name suggest, partial oxidation, reforming hydrocarbons to chemical energy carriers, requires far less oxygen than does full oxidation, fully reducing hydrocarbons to water and carbon dioxide. As shown in the figure, partial oxidation utilizes water (21) to provide oxygen and hydrogen where as full oxidation produces water.

[0136] This is an important observation due to the limited supply of oxygen. This embodiment attempts to do the same thing as the previous embodimentprovide dispatchable electricity without underutilized capital intense infrastructure. This made possible by using an oxy-fueled turbine which does not require Carbon Capture.

[0137] However, the supply of oxygen is finite and the opportunities to use the oxygen for oxyfuel turbines occurs at different times than the supply of oxygen. The use of partial oxidation enables a constant value for oxygen because there will almost always be a value for chemical energy carriers.

[0138] The constant value for oxygen provided by partial oxidation provides the reservoir of oxygen for the oxyfuel turbine to occasionally tap into. The volatility of the electricity market provides intermittent spikes in oxygen value. Should the price of oxygen also spike, partial oxidation can temporarily ceasebut this is not a large cost due to the low cost of reformers$200/kW.

[0139] Therefore, a supply of pure oxygen is available for the turbine. The goal of dispatchable heat engine, which provides electricity on demand, but a minority of the time, can be accomplished without any idling Carbon Capture equipment (FIG. 3) or any idling capital intensive heat sources (FIG. 2).

[0140] It should be mentioned that partial oxidation does result in the production of CO.sub.2 (23) However, this CO.sub.2 does not require gas separation, or Carbon Capture in the traditional sense. CO.sub.2 in this case is separated from hydrogen, need to be separated anyway. This can be done through a membrane or pressure swing absorption and is viewed as a minor inconvenience as hydrogen is so small that is it relatively easy to separate.

[0141] FIG. 4 illustrates the Thermal Hydrogen storage system. The system consists of the energy components shown and labeled. This is an energy system intended to reform chemical energy carriers and hydrocarbons to pumpable liquid fuels with the minimum capital intensity and the minimum energy lost.

[0142] This is accomplished by allowing most of the chemical energy carrier produced in the system to come from auto-thermal reforming, a process which is neither exothermic or endothermic. The waste heat of all exothermic processes, as labeled in the FIG. 24), are intended to augment partial oxidation of hydrocarbons.

[0143] Methanol is produced and stored in liquid form. Methanol acts as the ultimate source of storage in the economy. Methanol is produced from syngas and requires half the amount of oxygen as hydrogen production. It can be stored for an infinitely long period, and then used in a fuel cell which can be can provide power to the grid. The liquid nature of refueling provides distributed capacity with unmatchable reliabilityin an emergency, cars can simply refuel.

[0144] For the system as a whole, methanol can be reformed easily back into syngas, and it can then be converted to hydrogen using the water gas shift reaction (25). Because the other fuels require cold storage, and because oxygen supply is intermittent, this methanol provides the function of minimizing the need for cold storage.

[0145] Cold storage is provided by utilizing the wasted cooling of the air separation unit. This can be provided by either cold oxygen or cold nitrogen, but the embodiment shown uses the nitrogen. The cooling from the ASU minimizes the amount of compressive work required to store ammonia (26), oxygen (27), and to sequester CO.sub.2 (28).

[0146] The cooling provided to these chemicals is not wasted as it can be recollected after these chemicals are pumped to the pressure required for distribution at atmospheric temperature. After the cold liquids are pumped to pressure, their cooling is transferred once again to the incoming air to the ASU.

[0147] FIG. 5 illustrate the Thermal Hydrogen distribution system. Methanol is distributed to the gas tank of the vehicle (29). The waste heat from the SOFC is utilized to reform methanol back into syngas (30), to preheat incoming air (31), and then to heat the vehicle cabin (32).

[0148] The syngas is then utilized in a solid oxide fuel cell producing only carbonated water (33) which is not diluted with nitrogen (34). Solid oxide fuel cells can perform this function because the oxygen crosses the electrolyte rather than hydrogen. Because only carbonated water is produced, the products are five to ten time smaller than the exhaust from an internal combustion vehicle.

[0149] The CO.sub.2 (and possibly also the water) is stored onboard the vehicle (35), recollected by the gas station, returned to the CO.sub.2 sequestration network either through piping or by utilizing the empty methanol truck to move the CO.sub.2.

[0150] The following numbered clauses set out specific embodiments that may be useful in understanding the present invention:

1. A method of operating a system comprising an electrical power plant, an electrolyser connected to a regional electrical power grid, and a hydrocarbon oxidation device, comprising:

[0151] providing water and/or carbon dioxide to the electrolyser;

[0152] providing electricity from the regional electrical power grid to the electrolyser for electrolysis of the water and/or carbon dioxide to produce oxygen; and

[0153] providing the oxygen from the electrolyser to the hydrocarbon oxidation device for the oxidation of a hydrocarbon.

2. The method of clause 1 wherein the electrical power plant has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is less than two times the regional wholesale cost of natural gas.
3. The method of clause 1 or 2 wherein the electrical power plant has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is less than three times the regional wholesale cost of natural gas.
4. The method of any one of clauses 1-3 wherein the electrolyser has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is more than one and a half times the regional wholesale cost of natural gas.
5. The method of any one of clauses 1-4 wherein the electrolyser has a utilization rate of less than 50% of its availability when the marginal price of electricity on the regional electrical power grid is more than two times the regional wholesale cost of natural gas.
6. The method of any one of clauses 1-5, wherein heat from the electrical power plant is provided to the electrolyser for heat-assisted electrolysis.
7. The method of any one of clauses 1-6, wherein electricity from the electrical power plant is provided to the electrolyser when supply of electricity from the electrical power plant exceeds other electricity demand.
8. The method of any one of clauses 1-7, wherein the hydrocarbon oxidation device at least partially oxidizes the hydrocarbon to produce hydrogen or syngas.
9. The method of any one of clauses 1-7, comprising providing the hydrogen or syngas to a solid oxide fuel cell.
10. The method of clause 8, wherein the hydrocarbon oxidation device is an auto-thermal reformer or hydrocarbon gasifier.
11. The method of clause 10, wherein the hydrocarbon is methane.
12. The method of clause 10, wherein the hydrocarbon is coal or biomass.
13. The method of any one of clauses 1-12, comprising providing the oxygen to an oxy-fueled power plant.
14. The method of clause 13, wherein the oxy-fueled power plant is an Allam cycle power plant.
15. The method of any one of clauses 1-14, wherein the electrical power plant is a nuclear power plant, a solar thermal or concentrated photovoltaic power plant, or geothermal power plant.
16. The method of any one of clauses 1-15, wherein the electrical power plant has an electricity generating capacity of at least 50 megawatts.
17. The method of any one of clauses 1-16, wherein the electrical power plant has an electricity generating capacity of at least 100 megawatts.
18. A system comprising:

[0154] an air separation unit, a hydrocarbon reformer, and a Haber-Bosch process unit;

[0155] wherein the air separation unit provides nitrogen to the Haber-Bosch process unit;

[0156] wherein the hydrocarbon reformer unit provides hydrogen to the Haber-Bosch process unit.

19. The system of clause 18 comprising a methanol reformer;

[0157] wherein the hydrocarbon reformer provides hydrogen and/or carbon monoxide to the methanol reformer.

20. The system of clause 19 comprising a water gas shift reaction providing hydrogen and/or carbon monoxide to the methanol reformer.
21. The system of clause 18 comprising a water gas shift reaction providing hydrogen to the Haber-Bosch process.
22. The system of clause 20 or 21 comprising a heat exchanger to transfer heat from carbon dioxide from the hydrocarbon reformer to nitrogen from the air separation unit.
23. The system of any one of clauses 18-22 comprising a heat exchanger to transfer heat from the ammonia from the Haber-Bosch process unit into nitrogen from the air separation unit.
24. The system of any one of clauses 18-23 comprising a heat exchanger to transfer heat from air entering the air separation unit to ammonia from the Haber-Bosch process unit, carbon dioxide from the hydrocarbon reformer and/or oxygen from the air separation unit.
25. A vehicle comprising:

[0158] a fuel tank containing methanol;

[0159] a heat exchanger arranged to convert the methanol into syngas; and

[0160] a solid oxide fuel cell arranged to receive the syngas and generate electricity;

[0161] wherein heat from the solid oxide fuel cell is transferred into the methanol through said heat exchanger.

26. The vehicle of clause 25 comprising an exhaust tank for receiving carbon dioxide, and/or water, from the solid oxide fuel cell.
27. The vehicle of clause 26 wherein the fuel tank and the exhaust tank are separated by a movable membrane that moves in response to a pressure differential between the fuel tank and the exhaust tank.
28. The vehicle of clause 26 wherein the exhaust tank is insulated with an insulation having an R-Value of at least 10.
29. The vehicle of clause 28 wherein the exhaust tank is insulated with an insulation having an R-Value of at least 20.
30. The vehicle of clause 28 or 29, wherein the exhaust tank stores the heat from exhaust from the solid oxide fuel cell for later release to the vehicle cabin or connecting member to outside heat demand.

[0162] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes, equivalents, and modifications that come within the spirit of the inventions defined by following claims are desired to be protected. All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference and set forth in its entirety herein.