ULTRA-HIGH TEMPERATURE PYROLYSIS SEPARATION OF HYDROGEN AND CARBON
20230294983 · 2023-09-21
Inventors
- James S. Swensen (Santa Barbara, CA, US)
- Stephen P. Gibbel (Falls City, OR, US)
- David S. Gibbel (Falls City, OR, US)
- Douglas E. Grunder (Mt. Vernon, IA, US)
- Simon K. Hodson (Santa Barbara, CA)
Cpc classification
C01B2203/0272
CHEMISTRY; METALLURGY
International classification
Abstract
A continuous hydrocarbon pyrolysis process to produce hydrogen gas and carbon includes exposing a hydrocarbon feedstock to an oxygen depleted combustion gas within a hydrocarbon pyrolysis zone. A valveless pulse combustor produces the combustion gas at a temperature greater than 2,400° C. The hydrocarbon feedstock and combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas comprising hydrogen and solid particles comprising carbon. The gas and solid particles exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C. A heat exchanger cools the gas and solid particles to a temperature less than 200° C. A gas absorber removes unwanted gas molecules from the gas and produce H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2. The H.sub.2 containing gas is continuously introduced to a H.sub.2 consuming facility.
Claims
1. A continuous hydrocarbon pyrolysis process to produce hydrogen gas and carbon comprising exposing a hydrocarbon feedstock to an oxygen depleted combustion gas within a hydrocarbon pyrolysis zone, wherein the combustion gas is produced by a valveless pulse combustor, wherein the combustion gas enter the hydrocarbon pyrolysis zone at a combustion gas temperature greater than 2,400° C., wherein the hydrocarbon feedstock and combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas comprising hydrogen and solid particles comprising carbon.
2. The hydrocarbon pyrolysis process according to claim 1, wherein the hydrocarbon feedstock is selected from gaseous, liquid, and solid hydrocarbon materials.
3. The hydrocarbon pyrolysis process according to claim 1, wherein the valveless pulse combustor is operated by burning a fuel with an oxygen source having an oxygen content greater than 50 vol. % oxygen.
4. The hydrocarbon pyrolysis process according to claim 3, wherein the oxygen source has an oxygen content greater than 85 vol. % oxygen.
5. The hydrocarbon pyrolysis process according to claim 3, wherein the oxygen source has an oxygen content greater than 90 vol. % oxygen.
6. The hydrocarbon pyrolysis process according to claim 1, wherein the oxygen depleted combustion gas has an oxygen content less than 2 vol. % oxygen.
7. The hydrocarbon pyrolysis process according to claim 1, wherein the oxygen depleted combustion gas has an oxygen content less than 1 vol. % oxygen.
8. The hydrocarbon pyrolysis process according to claim 1, wherein the residence time within the hydrocarbon pyrolysis zone is less than 5 seconds.
9. The hydrocarbon pyrolysis process according to claim 1, wherein the residence time within the hydrocarbon pyrolysis zone is less than 2 seconds.
10. The hydrocarbon pyrolysis process according to claim 1, wherein the gas and solid particles produced in the hydrocarbon pyrolysis zone exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C.
11. The hydrocarbon pyrolysis process according to claim 10, comprising cooling the gas and solid particles which exit the hydrocarbon pyrolysis zone to a temperature less than 200° C. in a heat exchanger.
12. The hydrocarbon pyrolysis process according to claim 11, comprising separating the solid particles from the gas.
13. The hydrocarbon pyrolysis process according to claim 12, comprising treating the gas to remove unwanted particles and gas molecules to produce H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2.
14. The hydrocarbon pyrolysis process according to claim 12, comprising treating the gas to remove unwanted particles and gas molecules to produce H.sub.2 containing gas having an H.sub.2 concentration greater than 90 vol. % H.sub.2.
15. The hydrocarbon pyrolysis process according to claim 13, comprising continuously introducing the H.sub.2 containing gas to a power generation facility without long-term storage.
16. The hydrocarbon pyrolysis process according to claim 13, comprising continuously introducing the H.sub.2 containing gas to a hydrometallurgical production facility without long-term storage.
17. The hydrocarbon pyrolysis process according to claim 14, comprising continuously introducing the H.sub.2 containing gas to a chemical production facility without long-term storage.
18. The hydrocarbon pyrolysis process according to claim 12, wherein the solid particles have a carbon content greater than 90 wt. % as characterized by CHNSO Analysis.
19. The hydrocarbon pyrolysis process according to claim 12, comprising heating the solid particles to a temperature greater than 2,500° C.
20. The hydrocarbon pyrolysis process according to claim 19, wherein the solid particles comprise carbon having a percent graphitization greater than 80% as characterized by X-Ray diffraction.
21. A system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon comprising: a valveless pulse combustor which burns a fuel and an oxygen source to produce a combustion gas, wherein the oxygen source comprises an oxygen content greater than 85 vol. % oxygen, wherein the combustion gas is oxygen depleted; a hydrocarbon pyrolysis zone configured to receive the combustion gas and a quantity of hydrocarbon feedstock, wherein the combustion gas enters the hydrocarbon pyrolysis zone at a temperature greater than 2,400° C., wherein the hydrocarbon feedstock and the combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas and solid particles comprising hydrogen gas and carbon, wherein the gas and solid particles produced in the hydrocarbon pyrolysis zone exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C.; and a heat exchanger configured to cool the gas and solid particles which exit the hydrocarbon pyrolysis zone to a temperature less than 200° C.
22. The system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon according to claim 21, comprising a gas/particle separator to separate the solid particles from the gas.
23. The system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon according to claim 22, wherein the gas/particle separator is selected from a cyclone gas/particle separator and a baghouse gas/particle separator.
24. The system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon according to claim 21, comprising a gas absorber to remove unwanted gas molecules from the gas and produce H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2.
25. A combined system for continuous hydrocarbon pyrolysis to produce hydrogen gas and to receive and burn the hydrogen gas to generate power comprising: a valveless pulse combustor which burns a fuel and an oxygen source to produce a combustion gas, wherein the oxygen source comprises an oxygen content greater than 85 vol. % oxygen, wherein the combustion gas is oxygen depleted; a hydrocarbon pyrolysis zone configured to receive the combustion gas and a quantity of hydrocarbon feedstock, wherein the combustion gas enters the hydrocarbon pyrolysis zone at a temperature greater than 2,400° C., wherein the hydrocarbon feedstock and the combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas and solid particles comprising hydrogen gas and carbon, wherein the gas and solid particles produced in the hydrocarbon pyrolysis zone exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C.; a heat exchanger configured to cool the gas and solid particles which exit the hydrocarbon pyrolysis zone to a temperature less than 200° C.; a gas/particle separator to separate the solid particles from the gas; a gas absorber to remove unwanted gas molecules from the gas and produce a continuous source of H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2; and a power generation facility connected to the continuous source of H.sub.2 containing gas which burns the H.sub.2 containing gas to generate power.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0037] In order that the manner in which the above-recited and other features and advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0038]
[0039]
[0040]
[0041]
[0042]
[0043]
[0044]
[0045]
[0046]
[0047]
[0048]
[0049]
[0050]
[0051]
DESCRIPTION OF THE INVENTION
[0052] This disclosure relates to a continuous hydrocarbon pyrolysis process to produce hydrogen gas and carbon. The process includes exposing a hydrocarbon feedstock to an oxygen depleted combustion gas within a hydrocarbon pyrolysis zone. The combustion gas is preferably produced by a valveless pulse combustor. When the hydrocarbon feedstock and combustion gas enter the hydrocarbon pyrolysis zone, the combustion gas has a temperature greater than 2,400° C. The hydrocarbon feedstock and combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas comprising hydrogen and solid particles comprising carbon.
[0053]
[0054] A valveless pulse combustor (VPC) is used as the heat source for the pyrolysis process. A fuel and an oxygen containing gas stream are mixed in the combustion chamber of the VPC. The oxygen content in the oxygen containing gas stream is concentrated, and preferably greater than 85 vol. %. In some embodiments, the oxygen content in the oxygen containing gas stream is greater than 90 vol. %. In some embodiments, the oxygen content in the oxygen containing gas stream is greater than 93 vol. %. Almost all of the remaining gas in the oxygen containing gas stream is N.sub.2 if the oxygen was concentrated out of atmospheric air. Very small amounts of other gases are present. For example, CO.sub.2 from the ambient air would also be present in the oxygen containing gas stream in the low ppm range.
[0055] An advantage of VPCs is they can operate at near stoichiometric combustion. This means that the oxygen content in the combustion gas exiting the VPC has a very low oxygen content. In some embodiments, the oxygen content in the combustion gas is less than 4 vol. % O.sub.2. In some embodiments, the oxygen content in the combustion gas is less than 3 vol. % O.sub.2. In some embodiments, the oxygen content in the combustion gas is less than 2 vol. % O.sub.2. Oxygen content in the combustion gas can even be less than 1 vol. %. For many combustion technologies, oxygen in the combustion gas is often >5 vol. % and can even be as high as 10 vol. % or more. If a hydrocarbon is used as a fuel, most combustor technologies cannot operate at <2 vol. % O.sub.2 in the combustion gas and still produce low CO content. The presence of large amounts of CO is an indicator of incomplete or inefficient combustion. At 2 vol. % O.sub.2, CO can be <100 ppm. At <1 vol. % O.sub.2, CO can be less than 300 ppm.
[0056] With an incoming oxygen containing gas stream >85 vol. % oxygen, combustion gas temperatures can exceed 2,400° C. At 90 vol. % oxygen, the temperature of the combustion gas exiting the VPC can reach as high as 3,000° C. or more. At 94 vol. % oxygen, the temperature of the combustion gas exiting the VPC can reach as high as 3,300° C. or more.
[0057] Non-limiting examples of methods for concentrating oxygen from air to produce oxygen containing gas where the oxygen content is >85 vol. % oxygen include pressure swing absorption, membrane absorption, vacuum pressure swing absorption, ionic liquid-based absorption, specialized liquid chemical-based absorption, aqueous-salt gas absorption, and aqueous-suspended solid gas absorption.
[0058] The fuel used by the VPC may be H.sub.2 gas. If hydrogen is used as the fuel, a fractionated portion of the hydrogen produced in pyrolysis separation of hydrogen and carbon is diverted to fuel the VPC to produce the heat necessary to drive the pyrolysis process which converts hydrocarbon into carbon and hydrogen. If H.sub.2 is burned in the VPC to produce the heat for pyrolysis, steam will be the main gas constituent in the combustion gas along with some N.sub.2 from the >85 vol,% O.sub.2 gas stream needed for high temperature combustion. No CO.sub.2 is produced when H.sub.2 is burned. The balanced chemical reaction for stoichiometric combustion of H.sub.2 is:
2H.sub.2+O.sub.2.fwdarw.2H.sub.2O.
[0059] The fuel used by the VPC may be a hydrocarbon gas such as natural gas, methane, propane, etc. The fuel used may be a solid hydrocarbon fuel such as lignite coal, brown coal, sub-bituminous coal, bituminous coal, anthracite coal, where the coal is a dry powder with less than 1 wt. % moisture and a particle size less than 150 μm. The fuel used may be a solid hydrocarbon such as solid biowaste from drying forest waste, farm waste, sawdust, wood chip waste, human or animal feces waste, plastic waste, rubber waster, car tire waste, etc. where the solid hydrocarbon fuel is a dry powder with less than 1 wt. % moisture and a particle size less than 150 μm. The fuel used may be a liquid hydrocarbon such as gasoline, diesel, biodiesel, biofuels, waste cooking oils, etc.
[0060] Pyrolysis separation of carbon and hydrogen is accomplished when hydrocarbon feedstock is injected into the >2,400° C. combustion gas stream which exits the VPC. Since the O.sub.2 content in the combustion gas from the VPC is very low, e.g., less than 2 vol. % and even more preferably less than 1 vol. %, there is very little O.sub.2 to react with the hydrocarbon feedstock in the Hydrocarbon Pyrolysis Zone. A reaction between the hydrocarbon feedstock and trace O.sub.2 within the >2,400° C. combustion gas stream will produce CO or CO.sub.2 and result in a combustion gas stream that is essentially oxygen free. The absence of oxygen in the combustion gas stream reduces the amount of carbon produced by the pyrolysis separation of hydrogen and carbon.
[0061] The >2,400° C. combustion gas stream immediately heats the hydrocarbon feedstock to a temperature greater than 1,200° C. which causes the hydrocarbon feedstock to undergo pyrolysis. The sonic pulses of the VPC aid in energy transfer to efficiently and rapidly heat the hydrocarbon feedstock. The feed rate of the hydrocarbon feedstock is controlled such that the combustion gas stream and particles exit the Hydrocarbon Pyrolysis Zone with a temperature >1,200° C. In some embodiments, the combustion gas stream and particles exit the Hydrocarbon Pyrolysis Zone with a temperature >1,300° C. In some embodiments, the combustion gas stream and particles exit the Hydrocarbon Pyrolysis Zone with a temperature >1,400° C. In some embodiments, the combustion gas stream and particles exit the Hydrocarbon Pyrolysis Zone with a temperature >1,500° C. In some embodiments, the combustion gas stream and particles exit the Hydrocarbon Pyrolysis Zone with a temperature >1,600° C. In other words, if a larger quantity of hydrocarbon feedstock is combined with the combustion gas stream, there may be greater cooling of the combustion gas stream. Similarly, if a smaller quantity of hydrocarbon feedstock is combined with the combustion gas stream, there is less cooling of the combustion gas stream resulting in a greater temperature when the combustion gas stream and particles exit the Hydrocarbon Pyrolysis Zone. Likewise, a hotter combustion gas stream may be able to heat and process a greater quantity of hydrocarbon feedstock.
[0062] In some embodiments, the amount of hydrocarbon feedstock combined with the combustion gas stream is controlled such that the temperatures of the gas and particles exiting the Hydrocarbon Pyrolysis Zone are greater than 2,500° C. As the particle temperature exceeds 2,500° C., and preferably in the range of 2,700° C. to 3,000° C. or more, the solid carbon particles transition from a carbonized material to a layered graphitized material. Under these conditions, the solid carbon particles are >98% carbon as characterized by CHNSO analysis. The percent graphitization is >80% as characterized by X-Ray diffraction (XRD). Operating at sufficiently high temperatures to graphitize the solid carbon particles causes conversion of the hydrocarbon feedstock to a high value solid carbon material.
[0063] The higher the temperature of the combustion gas stream, the more work can be done on the incoming hydrocarbon feedstock because there is a greater temperature difference between the combustion gas temperature and the >1,200° C. at which the solid carbon product and gases exit the Hydrocarbon Pyrolysis Zone.
[0064] The residence time for the gases and particles in the Hydrocarbon Pyrolysis Zone is less than 30 seconds. In non-limiting embodiments, the residence time for the gases and particles in the Hydrocarbon Pyrolysis Zone is less than 30 seconds, 25 seconds, 20 seconds, 18 seconds, 16 seconds, 14 seconds, 12 seconds, 10 seconds, 9 seconds, 8 seconds, 7 seconds, 6 seconds, 5 seconds, 4 seconds, 3 seconds, 2 seconds, and 1 second, where any of the stated values can form an upper or lower endpoint of a range. The entire exposure time of the hydrocarbon feedstock to the high temperature may be greater than a second due to transport time within process system equipment.
[0065] The Hydrocarbon Feedstock may be hydrocarbon gas such as natural gas, methane, propane, etc. The Hydrocarbon Feedstock used may be a solid hydrocarbon fuels such as lignite coal, brown coal, sub-bituminous coal, bituminous coal, anthracite coal, where the coal is a dry powder with less than 1 wt. % moisture and a particle size less than 500 μm particles size. The Hydrocarbon Feedstock used may be a solid hydrocarbon such as solid biowaste from drying forest waste, farm waster, human or animal feces waste, etc. where the Hydrocarbon Feedstock is a dry powder with less than 1 wt. % moisture and a particle size less than 500 μm particles size. The fuel used may be a liquid hydrocarbon such as gasoline, diesel, biodiesel, biofuel, waste cooking oils, etc.
[0066] In the oxygen depleted Hydrocarbon Pyrolysis Zone, at temperatures in excess of 600° C. to 700° C., hydrocarbons begin to carbonize. A hydrocarbon is a molecule made at least of carbon and hydrogen. Methane is one of the simplest hydrocarbons with a molecular formula of CH.sub.4 meaning each molecule of methane has one carbon atom and four hydrogen atoms. Carbonization of methane means that all the atoms other than carbon are driven off from the carbon atom leaving only carbon behind. In the case of methane, one atom of carbon and 4 atoms of hydrogen do not exit the process as atoms. Instead, other atoms of carbon find each other and form a carbon matrix consisting of 6 membered rings that extend to form a graphite-like layer. Multiple layers then stack upon one another until enough carbon atoms have united to no longer exist as a gas and/or vapor. Solid particles deposit from the gaseous and/or vapor phase to form submicron solid particles similar in morphology and properties to grades of carbon black. In contrast, the most common method for making carbon black from methane is the carbonization of methane in specialized incomplete combustions reactions where some of the methane is burned to produce heat to carbonize the remaining methane.
[0067] In the disclosed pyrolysis process, hydrocarbon is injected into a low oxygen content, high temperature combustion gas stream. There is virtually no O.sub.2 to react with the hydrocarbon to burn it and produce heat, CO or CO.sub.2, and H.sub.2O. As noted above, the small amount of O.sub.2 that is present (<1 vol. % of the combustion gas) will do this, but then the O.sub.2 content is zero. In the O.sub.2 depleted environment, the hydrocarbon carbonizes. In the case of methane, submicron particles of carbon black made almost completely of carbon form. There is no O.sub.2 to burn the hydrogen atoms. As a result, the hydrogen atoms combine together into H.sub.2 gas. The product of the pyrolysis reaction is solid carbon and H.sub.2 gas. If the temperature for the gases and carbon solids exiting the Hydrocarbon Pyrolysis Zone is greater than 1,200° C., carbonization approaches completion where the hydrocarbon is separated into H.sub.2 gas and solid carbon particles.
[0068] If the Hydrocarbon Feedstock is a solid, then hydrocarbon gases, hydrocarbon vapors, H.sub.2 gas, start to destructively distill from the Hydrocarbon Feedstock solid at temperature approximately greater than 300° C. The hydrocarbon gases may be methane, ethane, propane, etc. The hydrocarbon vapors can range from coal tar vapor to vapors of smaller organic compounds such as ring structures like benzene, multi-ring organic molecules, and molecules that would be liquids at room temperatures such as ethanol, methanol, decane, etc. These organic molecules are examples of solid and liquid hydrocarbons that may destructively distill from the coal particle and be present in the vapor phase. As these gases and vapors heat to >1,200° C., they carbonize and produce H.sub.2 gas, other carbonization gases, and submicron particles similar to carbon black, as was formed from the methane gas described above.
[0069] Larger solid char particles remain from the solid hydrocarbon feedstock particles. As these char particles increase in temperature to greater than 1,200° C., they carbonize and produce H.sub.2 gases, other carbonization gases, and large carbon particles from the char particles.
[0070] It should be noted that a solid hydrocarbon such as dry coal or dry plant matter or dry feces has a much more complex molecular structure than the simple CH.sub.4 of methane. Such solid hydrocarbons are usually characterized in an instrument that measures the wt. % of carbon (C), hydrogen (H), nitrogen (N), and sulfur (S). Oxygen (O) wt. % is then obtained by subtracting the sum of C, H, N, and S wt. %'s from 100 wt. %. Some call this CHNSO Analysis. The other carbonization gases mentioned above are gases containing N, S, and O that are driven from the carbon matrix as it carbonizes to become more and more pure carbon.
[0071] If the Hydrocarbon Feedstock is a liquid hydrocarbon, such as diesel, the liquid hydrocarbon is sprayed in into the >2,400° C. combustion gas stream as fine droplets, preferably with a droplet size less than 500 μm. The fine droplets of the liquid hydrocarbon vaporize immediately. As the liquid hydrocarbon vapor heats to greater than 1,200° C., it carbonizes and produces H.sub.2 gas. A small amount of other carbonization gases are also produced to the extent that atoms N, S, and O are present in the liquid hydrocarbon molecular structure. Submicron particles are produced similar to the carbon black which is formed from methane gas. A small amount of larger carbon char particles may also form.
[0072] Regardless of the Hydrocarbon Feedstock material, carbon particles that reach >1,200° C. will be greater than 90 wt. % carbon in CHNSO Analysis. For most Hydrocarbon Feedstocks, carbon content will be greater than 95 wt. % when the carbon particles reach >1,200° C.
[0073] After the Hydrocarbon Pyrolysis Zone, the particle laden gas stream goes to a Heat Exchanger that reduces the gas and particle temperature to <200° C. In some embodiments, the Heat Exchanger reduces the gas and particle temperature to less than 200° C., less than 175° C., less than 150° C., less than 125° C., or less than 100° C., where any of the stated values can form an upper or lower endpoint of a range. Taking into consideration the Ideal Gas Law and the equation PV=nRT, where P is pressure, V is volume, n is the number of gas moles, R is the Ideal Gas Constant, and T is the temperature in Kelvin, reducing the temperature from 1,200° C. to 200° C., under constant pressure, will result in a volume reduction of about 3.1 times, T.sub.in/T.sub.out=(1200+273.15)/(200+273.15)=3.1. The volume reduction resulting from cooling the gasses allows for smaller downstream pipes and equipment, including Gas Particles Separators, Gas Handling Machines, Gas Scrubber, Gas Adsorption, etc. The maximum temperature for continuous operation of a baghouse which is a type of Gas Particle Separator is generally less than 200° C. based on the bag material available.
[0074] The heat captured from the Heat Exchanger has value which can be used to perform work and otherwise make the disclosed process more efficient. Non-limiting uses of the recovered heat include preheat gas or raw materials and create superheated steam to drive a turbine to produce electricity.
[0075] The cooled particle laden gas then goes downstream to goes to Gas/Particle Separation equipment. Usually, a cyclone will be used followed by a baghouse as shown in
[0076] The carbon particles that reached >1,200° C. in the Hydrocarbon Pyrolysis Zone are mostly an amorphous solid of sp2 carbon where three carbons are connected by two single bonds and one double bond. Placing the probes of an ohm meter on the particle demonstrates their resistance less than about 20 ohms at 1 cm separation. The 1 cm separation between the probes of the ohm meter is spanned by many particles of the powder carbon product. The bulk density may be too low for physical electrical connection between the particles. Compressing the powder to greater bulk density may be necessary to measure the electrical resistance of the carbon particles, especially the low bulk density carbon black-like particles collected from the baghouse. The sp2 bonds are not ordered but instead connect carbon atoms in the particle together as an amorphous solid. X-ray diffraction may show the beginning of layered structures that would be considered low level graphitization. The temperature for significant graphitization was not reached in the Hydrocarbon Pyrolysis Zone.
[0077]
[0078] Referring again to the process shown in
[0079]
[0080] In
[0081] The H.sub.2 Power Generation Facility may burn H.sub.2 to produce superheated steam which drives a turbine to produce electricity. The H.sub.2 Power Generation Facility may burn H.sub.2 and use the combustion gas to directly drive a turbine to produce electricity.
[0082] In the system described in
[0083] The combustion exhaust gas from the H.sub.2 Power Generation Facility can exhaust to the air as shown in
2H.sub.2+O.sub.2.fwdarw.2H.sub.2O+heat.
[0084] Alternatively, as shown in
[0085] The H.sub.2 Containing Gas that exits the Pyrolysis Separation of Hydrogen and Carbon process has some N.sub.2 in it from the >85 vol. % oxygen containing gas stream used to combust the hydrocarbon in the VPC. There will be some CO.sub.2 from combustion of the hydrocarbon fuel in the VPC. Carbonization of the hydrocarbon can also produce CO and/or CO.sub.2 if there is oxygen present in the molecular structure. Combustion water produced when burning the hydrocarbon fuel will likely react with the Hydrocarbon Feedstock in the high temperature Pyrolysis Zone to produce CO and H.sub.2 and/or more preferably CO.sub.2 and H.sub.2. See the previous discussion on the Water-Gas Reaction and the Water-Gas Shift Reaction.
[0086]
[0087] After the Fugitive Particles are removed, Gas Absorption Equipment removes other gases besides H.sub.2 to produce a greater than 80 or 90 vol. % H.sub.2 gas stream for the H.sub.2 Power Generation Facility. Gases that may be removed are N.sub.2, CO.sub.2, CO, SOx, NOx, H.sub.2S, NH.sub.4, etc. These are non-limiting examples of gases that may be removed with gas absorption equipment. The method for gas adsorption may include pressure swing absorption, membrane absorption, vacuum pressure swing absorption, ionic liquid-based absorption, ammonia liquid-based absorption, aqueous-salt gas absorption, aqueous-suspended solid gas absorption, etc. These are non-limiting examples.
[0088] Many of the removed gases have value in chemical industries. Thus, the absorbed gases that are removed from the H.sub.2 containing Gas can be stored on-site until loadout is full and then shipped out as a product. CO.sub.2 can be sold into the food processing industry or sequestered by various techniques to keep it from entering into the atmosphere as a greenhouse gas.
[0089] A greater than 90 vol. % H.sub.2 gas stream that has had fugitive particles removed is an ideal fuel to be used in a new, highly efficient turbine-based combustion combined cycle H.sub.2 Power Plant rather than conversion of existing coal fired and liquid hydrocarbon fired power plants.
[0090] An alternative equipment installation is shown in
[0091]
[0092]
[0093]
[0094]
[0095] It should be understood that the disclosed invention is not limited to the specific equipment arrangements shown in
[0096] Other features and advantages of the present invention are apparent from the different examples that follow. The examples below illustrate different aspects and embodiments of the present invention and how to make and practice them. The examples do not limit the claimed invention. Although methods and materials similar or equivalent to those described herein can be used in the practice of the present invention, suitable methods and materials are described below. Based on the present disclosure the skilled artisan can identify and employ other components and methodology useful for practicing the present invention.
Example 1
[0097] 600 MW is a common size for a Coal-Fired Power Plant. The results for calculations that convert the heat in Btu/hr needed to produce 600 MW electricity at a 35% efficient Coal-Fired Power Plant are found in Table 1. Calculations summarized in Table 2 show that in order to operate a 35% efficient 600 MW Coal-Fired Power Plant burning the same coal used as the feedstock for the Pyrolysis Separation of Hydrogen and Carbon, 210.63 MTPH coal needs to be burned. An efficiency of 35% is an average to high efficiency for a coal fired power plant. Table 2 summarizes calculations which show 210.63 MTPH as-received 10% moisture coal are burned to operate a 35% efficient 600 MW Coal-Fired Power Plant.
TABLE-US-00001 TABLE 1 Convert 600 MW electricity to MM Btu/hr heat needed to produce electricity at a 35% efficient Coal-Fired Power Plant. 600 MW per hour Power Plant 35% efficiency for standard Coal Power Plant 1,714 MW/hr actual production 3,412,141 Btu/MW 5,849,384,571 Btu/hr for 600 MW Power Plant 5.12E+07 MM Btu/yr for 600 MW Power Plant
TABLE-US-00002 TABLE 2 MTPH of Coal needed to operate a 35% efficient 600 MW Coal-Fired Power Plant 14,000 Btu/lb Dry Coal 5% Ash Coal 10% Moisture of Wet Bailey Coal 12,600 Btu/lb As-received coal @10% moisture 2.78E+07 Btu/MT coal 210.63 MTPH Wet Coal 1,845,152 MT Coal/yr
[0098] The model coal is 5.0 wt. % ash and 10.0 wt. % moisture. 210.63 MTPH As-received coal*(1-10.0% moisture)*(1-5.0% ash) 180.09 moisture ash free (MAF) coal. Table 3 shows a mass balance that calculates the MTPH of CO.sub.2 produce when 210.63 MTPH of as-received coal with the CHNSO values shown is burned. The coal is the same that is used as a feedstock into the Pyrolysis Separation of Hydrogen and Carbon to produce enough H.sub.2 gas to operate an on-site 41% efficient H.sub.2 Power Generation Facility. 533.42 MTPH CO.sub.2 are produced when the 210.63 MTPH As-received coal or 180.09 MTPH MAF coal are burned. 533.42 MTPH CO.sub.2 represents the amount of CO.sub.2 that would be produced if 210.63 MTPH of the as-received coal were burned at a 35% efficient 600 MW Coal-Fired Power Plant.
[0099] The negative value of O.sub.2 represents the amount of O.sub.2 that is needed to stoichiometrically react with each element in the coal and burn it to the oxide form. The total amount of oxygen needed to burn the coal is 452.50 MTPH.
TABLE-US-00003 TABLE 3 Mass balance for burning MAF Coal at a 35% efficient 600 MW Coal-Fired Power Plant. C + O.sub.2 .fwdarw. 4H + O.sub.2 .fwdarw. 2N + O.sub.2 .fwdarw. S + O.sub.2 .fwdarw. Total Element wt. % MTPH CO.sub.2 2H.sub.2O 2NO SO.sub.2 MTPH Carbon 80.78% 145.48 −145.48 0.00 Hydrogen 5.24% 9.44 −9.44 0.00 Nitrogen 1.74% 3.13 −3.13 0.00 Sulfur 2.09% 3.76 −3.76 0.00 Oxygen 10.15% 18.28 −18.28 0.00 180.09 0.00 CO.sub.2 533.42 533.42 H.sub.2O 84.93 84.93 O.sub.2 −369.66 −75.49 −3.58 −3.76 −452.50 NO 6.71 6.71 SO.sub.2 7.53 7.53 0.00 0.00 0.00 0.00
Example 2
[0100] A Mass Balance for Pyrolysis Separation of Hydrogen and Carbon using Pittsburgh 8 Seam Coal as the Feedstock that produces enough H.sub.2 containing Fuel Gas to power a 600 MW Hydrogen Power Plant operating at 41% efficiency is shown in Table 4. CHNSO analysis of the coal feedstock was 80.78 wt. % Carbon, 5.24 wt. % Hydrogen, 1.74 wt. % Nitrogen, 2.09 wt. % Sulfur, and 10.15 wt. % Oxygen by difference on a MAF basis. The preferred moisture and ash of the coal feedstock into the Pyrolysis Separation of Hydrogen and Carbon Process is <1 wt. % moisture and <10% ash. The mass balance that is summarized in Table 4 used 610.55 MTPH of coal feedstock at 0.5% moisture and at 5.0% ash. A moisture of 0.5% or less is a more preferred embodiment. An ash content of 5% or less is a preferred embodiment. The Mass Balance summarized in the Table 4 below matches up with
[0101] If no CO.sub.2 gas absorption is done, then the mass balance summary in Table 4 shows that 307.5 MTPH of CO.sub.2 is produced by the Pyrolysis Separation of Hydrogen and Carbon that is coupled to a 41% efficient 600 MW H.sub.2 Power Generation Facility. The mass balance for burning coal in Table 3 shows that a 35% efficient 600 MW coal fired power plant produces 533.42 MTPH of CO.sub.2. (533.42−307.5)/533.42=42.4% Production of enough H.sub.2 in the H.sub.2 containing Fuel Gas to operate a 41% efficient 600 MW H.sub.2 Power Generation Facility via the Pyrolysis Separation of Hydrogen and Carbon where coal is the feedstock without any gas absorption equipment shows a 42.4% reduction in CO.sub.2 emissions in comparison to a 35% efficient 600 MW Coal-Fired Power Plant. One embodiment is >35% reduction in CO.sub.2 emissions. Another embodiment is >40% reduction in CO.sub.2 emissions. The mass balance also shows that the Fuel Gas is 69.13 vol. % H.sub.2 gas after Pyrolysis Separation of H.sub.2 and Carbon. One embodiment is a fuel gas that is >65% H.sub.2 gas.
[0102] The Mass Balance Summary shows 465.63 MTPH carbon is produced in the Pyrolysis Separation of Hydrogen and Carbon that produces enough H.sub.2 gas to power a 41% efficient H.sub.2 Power Generation Facility. The carbon could just be buried and sequestered. As discussed earlier, the carbon has value in various markets and can be readily sold into these markets and be used to develop new markets.
TABLE-US-00004 TABLE 4 Mass Balance for Pyrolysis Separation of Hydrogen and Carbon using Pittsburgh 8 Seam Coal as the Feedstock that produces H.sub.2 Containing Fuel Gas for a 41% efficient 600 MW Production Facility. mol % or Gases MTPH mol/hr m.sup.3/hr vol % mass % Gases Entering the Pulse Combustor CH.sub.4 48.37 3,023,012 67,355 — 100.00% Temperature (° C.) N.sub.2 10.81 385,916 8,598 6.00% 5.29% 20 O.sub.2 193.47 6,046,024 134,709 94.00% 94.71% Pressure (Pa) H.sub.2O — — — — — 13,790 CO.sub.2 — — — — — N.sub.2 + O.sub.2 204.28 6,431,940 143,308 100.00% 100.00% Total Gases Exiting the Pulse Combustor N.sub.2 10.81 385,916 113,806 4.08% 4.28% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 3,100 H.sub.2O 108.83 6,046,024 1,782,960 63.95% 43.08% Pressure (Pa) CO.sub.2 133.01 3,023,012 891,480 31.97% 52.65% −500 Total 252.65 9,454,952 2,788,246 100.00% Coal Added (ton/hr) 610.55 Gases Exiting the Hydrocarbon Pyrolysis Zone N.sub.2 10.81 385,916 53,413 1.41% 2.72% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 1,300 H.sub.2O 2.62 145,803 20,180 0.53% 0.66% Pressure (Pa) CO.sub.2 307.50 6,988,664 967,273 25.53% 77.34% −1,100 CO 0.00 0 0 0.00% 0.00% Solids Carbon (ton/hr) H.sub.2 37.84 18,922,393 2,618,973 69.13% 9.52% 465.63 NO 18.29 609,691 84,385 2.23% 4.60% SO.sub.2 20.51 320,395 44,345 1.17% 5.16% Total 397.57 27,372,862 3,788,570 100.00% 100.00% Gases Exiting the Heat Exchanger N.sub.2 10.81 385,916 14,944 1.41% 2.72% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 160 H.sub.2O 2.62 145,803 5,646 0.53% 0.66% Pressure (Pa) CO.sub.2 307.50 6,988,664 270,624 25.53% 77.34% −2,600 CO 0.00 0 0 0.00% 0.00% Solids Carbon (ton/hr) H.sub.2 37.84 18,922,393 732,737 69.13% 9.52% 465.63 NO 18.29 609,691 23,609 2.23% 4.60% SO.sub.2 20.51 320,395 12,407 1.17% 5.16% Total 397.57 27,372,862 1,059,967 100.00% 100.00% Gases Exiting the Cyclone N.sub.2 10.81 385,916 14,835 1.41% 2.72% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 155 H.sub.2O 2.62 145,803 5,605 0.53% 0.66% Pressure (Pa) CO.sub.2 307.50 6,988,664 268,656 25.53% 77.34% −3,000 CO 0.00 0 0 0.00% 0.00% Solids Carbon (ton/hr) H.sub.2 37.84 18,922,393 727,408 69.13% 9.52% 29.30 NO 18.29 609,691 23,438 2.23% 4.60% SO.sub.2 20.51 320,395 12,316 1.17% 5.16% Total 397.57 27,372,862 1,052,258 100.00% 100.00% Gases Exiting the Baghouse N.sub.2 10.81 385,916 15,069 1.41% 2.72% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 150 H.sub.2O 2.62 145,803 5,693 0.53% 0.66% Pressure (Pa) CO.sub.2 307.50 6,988,664 272,886 25.53% 77.34% −5,500 CO 0.00 0 0 0.00% 0.00% Solids Carbon (ton/hr) H.sub.2 37.84 18,922,393 738,861 69.13% 9.52% 0.00 NO 18.29 609,691 23,807 2.23% 4.60% SO.sub.2 20.51 320,395 12,510 1.17% 5.16% Total 397.57 27,372,862 1,068,826 100.00% 100.00% Gases Exiting the Gas Handling Machine N.sub.2 10.81 385,916 1,671 1.41% 2.72% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 50 H.sub.2O 2.62 145,803 631 0.53% 0.66% Pressure (Pa) CO.sub.2 307.50 6,988,664 30,255 25.53% 77.34% 525,000 CO 0.00 0 0 0.00% 0.00% Solids Carbon (ton/hr) H.sub.2 37.84 18,922,393 81,918 69.13% 9.52% 0.00 NO 18.29 609,691 2,639 2.23% 4.60% SO.sub.2 20.51 320,395 1,387 1.17% 5.16% Total 397.57 27,372,862 118,501 100.00% 100.00% Gases Exiting the Gas Absorption N.sub.2 5.40 192,958 862 0.83% 2.48% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 20 H.sub.2O 1.31 72,901 326 0.31% 0.60% Pressure (Pa) CO.sub.2 153.75 3,494,332 15,610 15.10% 70.62% 450,000 CO 0.00 0 0 0.00% 0.00% Solids Carbon (ton/hr) H.sub.2 37.84 18,922,393 84,528 81.75% 17.38% 0.00 NO 9.15 304,846 1,362 1.32% 4.20% Gas Adsorption SO.sub.2 10.25 160,197 716 0.69% 4.71% 50% Total 217.71 23,147,628 103,403 100.00% 100.00%
[0103] Gas absorption technology can be used after Pyrolysis Separation of Hydrogen and Carbon. For example, 50% absorption of all the gases other than the H.sub.2 in the H.sub.2 containing Fuel Gas for the H.sub.2 Power Generation Facility changes the composition of the H.sub.2 Containing Fuel Gas to >80 vol. % H.sub.2. The mass balance shows that 153.75 MTPH of CO.sub.2 is emitted from the entire process at 50% absorption of CO.sub.2 in the Gas Absorption step. For 80% absorption of CO.sub.2, 61.75 MTPH CO.sub.2 would be emitted. For 90% absorption of CO.sub.2, 30.75 MTPH CO.sub.2 would be emitted. Table 5 shows the vol. % H.sub.2 in the H.sub.2 Containing Fuel Gas and MTPH CO.sub.2 remaining in the H.sub.2 Containing Fuel Gas for 50% up to 90% Gas Absorption as well as for no gas absorption. For example, 50% Gas Absorption means that 50% of each gas other than H.sub.2 in the H.sub.2 Containing Fuel Gas are absorbed and removed from the gas stream. Additionally, the percentage reduction is shown for CO.sub.2 emissions from the Pyrolysis Separation of Hydrogen and Carbon process with gas absorption compared to CO.sub.2 produced in a 35% efficient 600 MW Coal-Fired Power Plant using the same coal that was used in the Pyrolysis Separation of Hydrogen and Carbon to produce the H.sub.2 Containing Fuel Gas for the on-site H.sub.2 Power Generation Facility. It should be noted that the percentage of gas absorption is based on moles or volume of the gas, not on the mass of the gas.
[0104] Approximately 533.42 tons of CO.sub.2 would be produced to run a 35% efficient 600 MW Coal-Fired Power Plant. At 50% gas absorption of all gases besides H.sub.2, 153.75 MTPH CO.sub.2 are emitted after Gas Absorption for a Pyrolysis Separation of Hydrogen and Carbon facility. CO.sub.2 reduction is (533.42−153.75)/533.42=71.2% reduction of CO.sub.2 compared to the emissions of a 600 MW coal fired power plant when 50% of gases other than H.sub.2 gas are absorbed from the product Fuel Gas produced in the process described herein when coal is used as the hydrocarbon feedstock. After absorption of 50% of gases that are not H.sub.2, the remaining Fuel Gas is 81.75 vol. % H.sub.2. Referring to data shown in Table 5, one embodiment of the Hydrogen Containing Fuel Gas produced by the process is >80 vol % H.sub.2. Another embodiment of the Hydrogen Containing Fuel Gas produced by the process is >90 vol % H.sub.2. One result of the overall process of combining Pyrolysis Separation of Hydrogen and Carbon and including gas absorption before the H.sub.2 Power Generation Facility is >70% reduction of CO.sub.2 emissions compared to CO.sub.2 emissions produced by a 600 MW coal fired power plant using the same coal as the feedstock. Another embodiment is >80% reduction in CO.sub.2 emissions compared to an equivalently sized MW Coal-Fired Power Plant using the same coal as the feedstock. Still another embodiment is >90% reduction in CO.sub.2 emissions compared to compared to a an equivalently sized MW Coal-Fired Power Plant using the same coal as the feedstock.
TABLE-US-00005 TABLE 5 Comparison of vol. % H.sub.2 and MTPH CO.sub.2 for the mass balance summary shown in Table 4 for the Pyrolysis Separation of Hydrogen and Carbon when gas absorption is added after pyrolysis. Reduction of CO.sub.2 emissions in comparison to an equivalent MW Coal-fired Power Plant is also shown. % Gas vol. % MTPH Reduction of Absorption H.sub.2 CO.sub.2 CO.sub.2 0% 69.13% 307.5 42.4% 50% 81.75% 153.75 71.2% 60% 84.84% 123 76.9% 70% 88.19% 92.25 82.7% 80% 91.80% 61.5 88.5% 90% 95.73% 30.75 94.2%
Example 3
[0105] CNG can be processed via Pyrolysis Separation of Carbon and Hydrogen to produce H.sub.2 that can be burned in a H.sub.2 Power Generation Facility. The results for calculations that convert 600 MW of electricity production to the heat in Btu/hr needed to produce 600 MW electricity at a 58% efficient Combined-Cycle CNG-Fired Power Plant are found in Table 6. Calculations summarized in Table 7 show that in order to operate a 58% efficient 600 MW Combined-Cycle CNG-Fired Power Plant, 79.04 MTPH CNG need to be burned. 58% is an average efficiency for a combined cycle natural gas fired power plant.
TABLE-US-00006 TABLE 6 Convert 600 MW electricity to MM Btu/hr heat needed to produce said electricity at a 58% efficient Combined-Cycle CNG-Fired Power Plant. 600 MW per hour Power Plant 58% Efficiency for standard CNG Power Plant 1,034 MW/hr actual production 3,412,141 Btu/MW 3,529,801,034 Btu/hr for 600 MW Power Plant 3.09E+07 MM Btu/yr for 600 MW Power Plant
TABLE-US-00007 TABLE 7 MTPH of CNG needed to operate a 58% efficient 600 MW Combined Cycle CNG-Fired Power Plant. 20,262 Btu/lb LHV CNG 4.47E+07 Btu/MT CNG 79.04 MTPH CNG 692,405 MT CNG/yr
[0106] Table 8 shows a mass balance that calculates the MTPH of CO.sub.2 produced when 79.04 MTPH is burned. 217.36 MTPH of CO.sub.2 are produced when 79.04 MTPH of CNG are burned. 217.36 MTPH represents the amount of CO.sub.2 that would be produced if 79.04 MTPH of CNG were burned at a 58% efficient 600 MW Combined Cycle CNG-Fired Power Plant that is 58% efficient. The negative value of O.sub.2 represents the amount of O.sub.2 that is needed to stoichiometrically react with each element in the CNG and burn it to the oxide form. The total amount of oxygen needed to burn the CNG is 316.17 MTPH.
TABLE-US-00008 TABLE 8 Mass balance for burning CNG at a 58% efficient 600 MW Combined-Cycle CNG-Fired Power Plant. C + O.sub.2 .fwdarw. 4H + O.sub.2 .fwdarw. Element wt. % MTPH CO2 2H.sub.2O MTPH Carbon 75.00% 59.28 −59.28 0.00 Hydrogen 25.00% 19.76 −19.76 0.00 79.04 0.00 CO.sub.2 217.36 217.36 H.sub.2O 177.84 177.84 O.sub.2 −158.08 −158.08 −316.17 0.00 0.00
Example 4
[0107] A Mass Balance for Pyrolysis Separation of Hydrogen and Carbon using compressed natural gas (CNG) as the Feedstock that produces enough H.sub.2 gas to power a 600 MW Hydrogen Power Plant operating at 41% efficiency is shown in Table 9. CNG is 75 wt. % carbon and 25 wt. % hydrogen. The mass balance that is summarized in Table 9 used 130.63 MTPH of CNG feedstock into the Hydrocarbon Pyrolysis Separation Process. The Mass Balance that is summarized in the table below matches up with
[0108] If no CO.sub.2 gas absorption is done, then the mass balance shows that 220.84 MTPH of CO.sub.2 is produced by the Pyrolysis Separation of Hydrogen and Carbon that is coupled to a 41% efficient 600 MW H.sub.2 Power Generation Facility. The mass balance for burning CNG in Table 8 shows that a 58% efficient 600 MW Combined-Cycle CNG fired power plant produces 217.36 MTPH of CO.sub.2. (217.36−220.84)/217.36=−1.6% reduction in CO.sub.2 by the Pyrolysis Separation of Hydrogen and Carbon process alone. In other words, the Pyrolysis Separation of Hydrogen and Carbon produces approximately the same amount of CO.sub.2 as burning CNG in a Combined-Cycle CNG-Fired Power Plant because of the high 58% efficiency of the Combined-Cycle CNG-Fired Power Plant. The mass balance also shows that the Fuel Gas is 77.83 vol. % H.sub.2 gas after Pyrolysis Separation of H.sub.2 and Carbon and before gas absorption. One embodiment is a fuel gas that is >70% H.sub.2 gas.
[0109] The Mass Balance Summary shows 72.87 MTPH carbon is produced in the process that produces enough H.sub.2 gas to power a 41% efficient H.sub.2 Power Generation Facility. The particle size of the carbon is sub-micron in size, similar to carbon black. The production of a valuable solid carbon product while not producing appreciably more CO.sub.2 than a high efficiency combined cycle CNG fired power plant is an advantage over the just burning CNG at the power plant. As discussed earlier, the carbon has value in various markets and can be readily sold into these markets as well as be used to develop new markets.
TABLE-US-00009 TABLE 9 Mass Balance for Pyrolysis Separation of Hydrogen and Carbon using CNG as the Feedstock that produces .sub.H2 containing Fuel Gas for a 41% efficient 600 MW Production Facility. mol % or Gases MTPH mol/hr m.sup.3/hr vol % mass % Gases Entering the Pulse Combustor CH.sub.4 40.31 2,519,177 56,129 — 100.00% Temperature (° C.) N.sub.2 9.00 321,597 7,165 6.00% 5.29% 20 O.sub.2 161.23 5,038,353 112,258 94.00% 94.71% Pressure (Pa) H.sub.2O — — — — — 13,790 CO.sub.2 — — — — — N.sub.2 + O.sub.2 170.23 5,359,950 119,423 100.00% 100.00% Total Gases Exiting the Pulse Combustor N.sub.2 9.00 321,597 94,838 4.08% 4.28% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 3,100 H.sub.2O 90.69 5,038,353 1,485,800 63.95% 43.08% Pressure (Pa) CO.sub.2 110.84 2,519,177 742,900 31.97% 52.65% −500 Total 210.54 7,879,127 2,323,539 100.00% CNG Added (ton/hr) 130.63 Gases Exiting the Hydrocarbon Pyrolysis Zone N.sub.2 9.00 321,597 44,511 1.33% 3.36% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 1,300 H.sub.2O 0.69 38,353 5,308 0.16% 0.26% Pressure (Pa) CO.sub.2 220.84 5,019,177 694,684 20.69% 82.31% −1,100 H.sub.2 37.76 18,879,438 2,613,028 77.83% 14.07% Solids Carbon (ton/hr) Total 268.30 24,258,564 3,357,532 100.00% 100.00% 72.87 Gases Exiting the Heat Exchanger N.sub.2 9.00 321,597 12,453 1.33% 3.36% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 160 H.sub.2O 0.69 38,353 1,485 0.16% 0.26% Pressure (Pa) CO.sub.2 220.84 5,019,177 194,359 20.69% 82.31% −2,600 H.sub.2 37.76 18,879,438 731,074 77.83% 14.07% Solids Carbon (ton/hr) Total 268.30 24,258,564 939,371 100.00% 100.00% 72.87 Gases Exiting the Cyclone N.sub.2 9.00 321,597 12,363 1.33% 3.36% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 155 H.sub.2O 0.69 38,353 1,474 0.16% 0.26% Pressure (Pa) CO.sub.2 220.84 5,019,177 192,945 20.69% 82.31% −3,000 H.sub.2 37.76 18,879,438 725,756 77.83% 14.07% Solids Carbon (ton/hr) Total 268.30 24,258,564 932,539 100.00% 100.00% Gases Exiting the Baghouse N.sub.2 9.00 321,597 12,557 1.33% 3.36% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 150 H.sub.2O 0.69 38,353 1,498 0.16% 0.26% Pressure (Pa) CO.sub.2 220.84 5,019,177 195,983 20.69% 82.31% −5,500 H.sub.2 37.76 18,879,438 737,184 77.83% 14.07% Solids Carbon (ton/hr) Total 268.30 24,258,564 947,222 100.00% 100.00% 0.00 Gases Exiting the Gas Handling Machine N.sub.2 9.00 321,597 1,392 1.33% 3.36% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 50 H.sub.2O 0.69 38,353 166 0.16% 0.26% Pressure (Pa) CO.sub.2 220.84 5,019,177 21,729 20.69% 82.31% 525,000 H.sub.2 37.76 18,879,438 81,732 77.83% 14.07% Solids Carbon (ton/hr) Total 268.30 24,258,564 105,019 100.00% 100.00% 0.00 Gases Exiting the Gas Absorption N.sub.2 4.50 160,799 718 0.75% 2.94% Temperature (° C.) O.sub.2 0.00 0 0 0.00% 0.00% 20 H.sub.2O 0.35 19,177 86 0.09% 0.23% Pressure (Pa) CO.sub.2 110.42 2,509,588 11,211 11.64% 72.16% 450,000 H.sub.2 37.76 18,879,438 84,337 87.53% 24.67% Solids Carbon (ton/hr) Total 153.03 21,569,001 96,351 100.00% 100.00% 0.00 Gas Adsorption 50%
[0110] Gas absorption technology can be used after Pyrolysis Separation of Hydrogen and Carbon. 50% absorption of all the gases other than H.sub.2 produces a Fuel Gas for the H.sub.2 Power Generation Facility that is >80 vol. % H.sub.2. The mass balance shows that 110.42 MTPH of CO.sub.2 is emitted from the entire process at 50% absorption of CO.sub.2 in the Gas Absorption step. For 80% absorption of CO.sub.2, 44.17 MTPH CO.sub.2 would be emitted. For 90% absorption of CO.sub.2, 22.08 MTPH CO.sub.2 would be emitted. When all other gases are absorbed at the shown percentage, Table 10 shows the vol. % H.sub.2 in the Fuel Gas, MTPH CO.sub.2 remaining in the Fuel Gas, and the % reduction in CO.sub.2 emissions compared to CO.sub.2 produced in a 58% efficient combined cycle 600 MW CNG fired power plant. It should be noted that the percentage of gas absorption is based on moles or volume of the gas, not on the mass of the gas. The table below shows % Gas Absorption for gasses other than H.sub.2 gas from 50% up to 90%.
[0111] If the CNG is burned at a 58% efficient 600 MW Combined Cycle CNG-Fired power plant, approximately 217.36 tons of CO.sub.2 would be produced. If 50% of gases other than hydrogen are absorbed in the fuel gas from Hydrocarbon Pyrolysis Separation, then there would be a (217.36−110.42)/217.36=49.2% reduction of CO.sub.2 compared to the emissions of the 58% efficient Combined-Cycle CNG-Fired power plant. After absorption of 50% of gases that are not H.sub.2, the remaining Fuel Gas is 87.53 vol. % H.sub.2. Referring to data in Table 10, one embodiment of the H.sub.2 Containing Fuel Gas produced by Pyrolysis Separation of Hydrogen and Carbon plus Gas Absorption is >85 vol % H.sub.2. Another embodiment of the H.sub.2 Containing Fuel Gas produced by Pyrolysis Separation of Hydrogen and Carbon plus Gas Absorption is >90 vol % H.sub.2. One result of the overall process of combining Pyrolysis Separation of Hydrogen and Carbon with CNG as the feedstock and including gas absorption before the H.sub.2 Power Generation Facility is >50% reduction of CO.sub.2 emissions compared to an equivalently sized MW Combined-Cycle CNG-Fired Power Plant. Another embodiment is >60% reduction in CO.sub.2 emissions when gas absorption technology is used an equivalently sized MW Combined-Cycle CNG-Fired Power Plant. Still another embodiment is >70% reduction in CO.sub.2 emissions when gas absorption technology is used an equivalently sized MW Combined-Cycle CNG-Fired Power Plant. Still another embodiment is >80% reduction in CO.sub.2 emissions when gas absorption technology is used an equivalently sized MW Combined-Cycle CNG-Fired Power Plant.
TABLE-US-00010 TABLE 10 Comparison of vol. % H.sub.2 and MTPH CO.sub.2 for the mass balance summary shown in Table 9 for the Pyrolysis Separation of Hydrogen and Carbon when gas absorption is added after pyrolysis. Reduction of CO.sub.2 emissions in comparison to an equivalent MW Coal-fired Power Plant is also shown. % Gas Absorption vol. % H.sub.2 MTPH CO.sub.2 Reduction of CO.sub.2 0% 77.83% 220.84 −1.6% 50% 87.53% 110.42 49.2% 60% 89.77% 88.34 59.4% 70% 92.13% 66.25 69.5% 80% 94.61% 44.17 79.7% 90% 97.23% 22.08 89.8%
Example 5
[0112] Pittsburgh #8 Seam Coal was the hydrocarbon feedstock for the Pyrolysis Separation of Hydrogen and Carbon process as disclosed herein. Solid carbon particles were separated and subjected to a Secondary Heating Zone. Three samples of carbonized solid carbon particles that exited the process at 1,200° C. (S-1200), graphitized solid carbon particles that exited the system at 2,500° C. (S-2500), graphitized solid carbon particles that exited the system at 2,700° C. (S-2700), and a reference synthetic graphite made from standard synthetic graphite processes known in the industry (G-ref) are listed in Table 11. Additional samples heated to different temperatures are also reported in Table 11, 1,000° C. (S-1000), 1,500° C. (S-1500), 1,800° C. (S-1800). 2,000° C. (S-2000), and 2,900° C. (S-2900). Table 11 shows that heat treatment at high temperature influences the carbon content of the solid carbon particles. Carbon content goes from 80.78% in the as-received coal feedstock to 95.23% for the product that reached a temperature of 1,200° C. to >99% for samples processed above 2,500° C. The CHNSO Analysis is reported on a MAF basis. After high temperature treatment, meaning above 2,500° C., the ash content is less than 1 wt. % at 2500° C. and less than 0.13 wt. % at 2700° C. Nearly all the mineral matter in the coal sample (including clay, sulfide, carbonate, silica and sulfate etc.) evaporated as metals or compounds. As seen in Table 11, the low ash content of the S-2500 and S-2700 were similar to the reference synthetic graphite G-ref. Samples S-2500 and S-2700 and G-ref contained around 99.90 wt. % carbon on a MAF basis while there are negligible other elements. The data in Table 11 shows that the samples are carbonized at >95% carbon on a MAF basis for treatments greater than 1,200° C. A sample that is >90% carbon on a MAF basis is also considered to be carbonized. Further analysis is needed to show that a conversion from amorphous carbonized carbon to graphitized carbon occurs at the higher temperatures, e.g., 2,500° C. and 2,700° C. This analysis is shown below.
TABLE-US-00011 TABLE 11 Proximate Analysis and Ultimate Analysis of coal hydrocarbon feedstock and samples treated at various high temperatures. Proximate analysis (wt. %) Ultimate analysis (wt. %) Sample M.sub.ad A.sub.d VM.sub.d FC.sub.d C.sub.MAF H.sub.MAF N.sub.MAF S.sub.MAF O.sub.MAF.sup.a Coal Feed 1.90 4.72 33.47 61.81 80.78 5.24 1.74 2.090 10.15 S-1000 0.15 6.19 2.61 93.66 92.51 0.223 0.96 0.577 5.73 S-1200 0.04 6.13 2.38 91.49 95.23 0.883 0.53 0.278 3.079 S-1500 0.05 4.88 2.08 95.07 97.99 0.058 0.2 0.167 1.785 S-1800 0.05 2.52 1.89 97.43 99.45 0.061 0.03 0.030 0.429 S-2000 0.05 1.21 1.64 98.74 99.881 0.076 0.02 0.023 0 S-2500 0.02 0.92 0.88 98.20 99.82 0.078 0.03 0.068 0 S-2700 0.03 0.46 0.83 99.16 99.90 0.055 0.02 0.022 0 S-2900 0.05 0.31 0.79 99.86 99.869 0.087 0.02 0.027 0 G-ref 0.00 0.56 1.31 98.13 99.89 0.059 0.025 0.024 0 M, moisture content A, ash content VM, volatile matter content FC, fixed carbon content .sub.adair dry basis .sub.ddry basis .sub.MAFmoisture ash free .sup.aby difference C and O, the carbon content of S-2500, S2700, and G-ref was over 100% which was in the range of systemic error. Oxygen content was assumed to be zero for those samples, and the carbon content was obtained by difference.
[0113]
[0114]
TABLE-US-00012 TABLE 12 Structure parameters of synthetic graphite samples d.sub.(002) Lc.sub.002) Sample (nm) (nm) N G (%) I.sub.D/I.sub.G S-1200 — — — — 0.83 S-2500 0.3369 19.26 58.18 82.69 0.51 S-2700 0.3366 26.97 81.12 85.59 0.16 G-Ref 0.3364 50.57 151.34 88.49 0.10 d.sub.(002) is calculated by Bragg equation: d.sub.(002) = λ/2sinθ.sub.(002); Lc.sub.(002) is the average crystallite height: Lc.sub.(002) = 0.89λ/(β.sub.002) × cosθ.sub.(002)); N is the carbon layer accumulation in Microcrystals: N = Lc.sub.(002)/d.sub.(002) + 1; G is the graphitization degree: G = (0.3340-d.sub.(002))/(0.3440-0.3354); I.sub.D/I.sub.G is the intensity of D-peak divided by G-peak.
[0115] Raman spectra of all samples are shown in
[0116] The exposure of a hydrocarbon to the High Temperature Pyrolysis Separation of Hydrogen and Carbon process disclosed herein produces a carbon product with enhanced value in comparison to the hydrocarbon feedstock. The enhanced value may be measured in different ways. For instance, increased carbon content increased its value. Thus, the carbon content may be increased from 75 wt. % in methane gas to become a solid carbon product with greater than 95 wt. % carbon or more. In the case of coal as the hydrocarbon feedstock, the carbon content may increase from about 80 wt. % with other element impurities to 95 wt. % carbon or more with a reduction HNSO from the carbon matrix and a reduction in mineral contaminants. In the case of biowaste, wood, and lignite coal, the carbon content of the dry solid hydrocarbon can be as high as 50 wt. % or lower. The High Temperature Pyrolysis Separation of Hydrogen and Carbon process can produce a carbon product from these solid hydrocarbon feedstocks that are about 90 wt. % carbon or more while driving off HNSO and mineral contaminants. If raised to a high enough temperature, greater than 2,500° C. and reaching up to 3,000° C. or more, the carbon content approaches and exceeds 99%. Furthermore, characterization of the carbon for graphitization can show a degree of graphitization of about 80% or more. The increase in degree of graphitization can also be looked at as an increase in commercial value. Carbonized carbon and graphitized solid carbon have at least two times the commercial value per ton in the marketplace compared to the feedstock hydrocarbons.
Embodiments
[0117] Various embodiments are listed below. It will be understood that the embodiments listed below may be combined with all aspects and other embodiments in accordance with the scope of the invention.
[0118] Embodiment 1. A continuous hydrocarbon pyrolysis process to produce hydrogen gas and carbon comprising exposing a hydrocarbon feedstock to an oxygen depleted combustion gas within a hydrocarbon pyrolysis zone, wherein the combustion gas is produced by a valveless pulse combustor, wherein the combustion gas enter the hydrocarbon pyrolysis zone at a combustion gas temperature greater than 2,400° C., wherein the hydrocarbon feedstock and combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas comprising hydrogen and solid particles comprising carbon.
[0119] Embodiment 2. The hydrocarbon pyrolysis process according to Embodiment 1, wherein the hydrocarbon feedstock is selected from gaseous, liquid, and solid hydrocarbon materials.
[0120] Embodiment 3. The hydrocarbon pyrolysis process according to Embodiments 1 or 2, wherein the valveless pulse combustor is operated by burning a fuel with an oxygen source having an oxygen content greater than 50 vol. % oxygen.
[0121] Embodiment 4. The hydrocarbon pyrolysis process according to Embodiments 1 or 2, wherein the oxygen source has an oxygen content greater than 85 vol. % oxygen.
[0122] Embodiment 5. The hydrocarbon pyrolysis process according to Embodiments 1 or 2, wherein the oxygen source has an oxygen content greater than 90 vol. % oxygen.
[0123] Embodiment 6. The hydrocarbon pyrolysis process according to any preceding Embodiment, wherein the oxygen depleted combustion gas has an oxygen content less than 2 vol. % oxygen.
[0124] Embodiment 7. The hydrocarbon pyrolysis process according to any preceding Embodiment, wherein the oxygen depleted combustion gas has an oxygen content less than 1 vol. % oxygen.
[0125] Embodiment 8. The hydrocarbon pyrolysis process according to any preceding Embodiment, wherein the residence time within the hydrocarbon pyrolysis zone is less than 5 seconds.
[0126] Embodiment 9. The hydrocarbon pyrolysis process according to any preceding Embodiment, wherein the residence time within the hydrocarbon pyrolysis zone is less than 2 seconds.
[0127] Embodiment 10. The hydrocarbon pyrolysis process according to any preceding Embodiment, wherein the gas and solid particles produced in the hydrocarbon pyrolysis zone exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C.
[0128] Embodiment 11. The hydrocarbon pyrolysis process according to Embodiment 10, comprising cooling the gas and solid particles which exit the hydrocarbon pyrolysis zone to a temperature less than 200° C. in a heat exchanger.
[0129] Embodiment 12. The hydrocarbon pyrolysis process according to Embodiment 11, comprising separating the solid particles from the gas.
[0130] Embodiment 13. The hydrocarbon pyrolysis process according to Embodiment 12, comprising treating the gas to remove unwanted particles and gas molecules to produce H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2.
[0131] Embodiment 14. The hydrocarbon pyrolysis process according to Embodiment 12, comprising treating the gas to remove unwanted particles and gas molecules to produce H.sub.2 containing gas having an H.sub.2 concentration greater than 90 vol. % H.sub.2.
[0132] Embodiment 15. The hydrocarbon pyrolysis process according to Embodiment 13, comprising continuously introducing the H.sub.2 containing gas to a power generation facility without long-term storage.
[0133] Embodiment 16. The hydrocarbon pyrolysis process according to Embodiment 13, comprising continuously introducing the H.sub.2 containing gas to a hydrometallurgical production facility without long-term storage.
[0134] Embodiment 17. The hydrocarbon pyrolysis process according to Embodiment 14, comprising continuously introducing the H.sub.2 containing gas to a chemical production facility without long-term storage.
[0135] Embodiment 18. The hydrocarbon pyrolysis process according to Embodiment 12, wherein the solid particles have a carbon content greater than 90 wt. % as characterized by CHNSO Analysis.
[0136] Embodiment 19. The hydrocarbon pyrolysis process according to Embodiment 12, comprising heating the solid particles to a temperature greater than 2,500° C.
[0137] Embodiment 20. The hydrocarbon pyrolysis process according to Embodiment 19, wherein the solid particles comprise carbon having a percent graphitization greater than 80% as characterized by X-Ray diffraction.
[0138] Embodiment 21. A system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon comprising: a valveless pulse combustor which burns a fuel and an oxygen source to produce a combustion gas, wherein the oxygen source comprises an oxygen content greater than 85 vol. % oxygen, wherein the combustion gas is oxygen depleted; a hydrocarbon pyrolysis zone configured to receive the combustion gas and a quantity of hydrocarbon feedstock, wherein the combustion gas enters the hydrocarbon pyrolysis zone at a temperature greater than 2,400° C., wherein the hydrocarbon feedstock and the combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas and solid particles comprising hydrogen gas and carbon, wherein the gas and solid particles produced in the hydrocarbon pyrolysis zone exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C.; and a heat exchanger configured to cool the gas and solid particles which exit the hydrocarbon pyrolysis zone to a temperature less than 200° C.
[0139] Embodiment 22. The system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon according to Embodiment 21, comprising a gas/particle separator to separate the solid particles from the gas.
[0140] Embodiment 23. The system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon according to Embodiment 22, wherein the gas/particle separator is selected from a cyclone gas/particle separator and a baghouse gas/particle separator.
[0141] Embodiment 24. The system for continuous hydrocarbon pyrolysis to produce hydrogen gas and carbon according to any preceding Embodiment, comprising a gas absorber to remove unwanted gas molecules from the gas and produce H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2.
[0142] Embodiment 25. A combined system for continuous hydrocarbon pyrolysis to produce hydrogen gas and to receive and burn the hydrogen gas to generate power comprising: a valveless pulse combustor which burns a fuel and an oxygen source to produce a combustion gas, wherein the oxygen source comprises an oxygen content greater than 85 vol. % oxygen, wherein the combustion gas is oxygen depleted; a hydrocarbon pyrolysis zone configured to receive the combustion gas and a quantity of hydrocarbon feedstock, wherein the combustion gas enters the hydrocarbon pyrolysis zone at a temperature greater than 2,400° C., wherein the hydrocarbon feedstock and the combustion gas have a residence time within the hydrocarbon pyrolysis zone less than 30 seconds to cause pyrolysis of the hydrocarbon feedstock and produce gas and solid particles comprising hydrogen gas and carbon, wherein the gas and solid particles produced in the hydrocarbon pyrolysis zone exit the hydrocarbon pyrolysis zone at a temperature greater than 1,200° C.; a heat exchanger configured to cool the gas and solid particles which exit the hydrocarbon pyrolysis zone to a temperature less than 200° C.; a gas/particle separator to separate the solid particles from the gas; a gas absorber to remove unwanted gas molecules from the gas and produce a continuous source of H.sub.2 containing gas having an H.sub.2 concentration greater than 80 vol. % H.sub.2; and a power generation facility connected to the continuous source of H.sub.2 containing gas which burns the H.sub.2 containing gas to generate power.
[0143] The described embodiments and examples are all to be considered in every respect as illustrative only, and not as being restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.