阅读说明：本技术 生成氢的方法和系统 (Method and system for generating hydrogen ) 是由 D·安德森 C·C·席尔瓦 于 2020-03-25 设计创作，主要内容包括：公开了用于由二氧化碳生成氢的方法和系统。用于由二氧化碳气流生成氢气流的方法和系统包括,在光合作用步骤中使用藻源将第一废二氧化碳气流转化为有机原料。然后在生物分解步骤中使用生物体将有机原料转化为氢气流和气态副产物。然后可以收集所生成的氢气。(Methods and systems for generating hydrogen from carbon dioxide are disclosed. Methods and systems for generating a hydrogen stream from a carbon dioxide gas stream include converting a first waste carbon dioxide gas stream to an organic feedstock using an algae source in a photosynthesis step. The organic feedstock is then converted to a hydrogen stream and gaseous byproducts in a biological decomposition step using biomass. The generated hydrogen gas may then be collected.)

1. A method for generating a hydrogen stream from a carbon dioxide gas stream, the method comprising:

(i) converting the first waste carbon dioxide gas stream into an organic feedstock using an algae source in a photosynthesis step; and

(ii) in the biological decomposition step, the organic feedstock is converted to a first hydrogen stream and gaseous byproducts using biomass.

2. The method of claim 1, further comprising collecting the gaseous by-product of step (ii) and filtering the gaseous by-product to separate a second waste carbon dioxide gas stream.

3. The method of claim 2, further comprising diverting the second spent carbon dioxide stream to step (i).

4. A process as claimed in any one of claims 1 to 3 wherein step (i) is carried out in a microbial reactor equipped with a photon source.

5. The method of any one of claims 1-4, wherein step (ii) comprises an aerobic biodegradation step and an anaerobic biodegradation step.

6. The method of claim 5, wherein the aerobic biodegradation step is performed prior to the anaerobic biodegradation step.

7. The method of claim 6, wherein at least a portion of the product of the aerobic biological decomposition step is mixed with the algae source in step (i) prior to the anaerobic biological decomposition step.

8. The method of any one of claims 1-7, wherein step (ii) is performed in one or more biological decomposition reactors.

9. The method of any one of claims 1-8, further comprising adjusting the temperature of step (i) and/or step (ii).

10. The method of any of claims 1-9, wherein the first waste carbon dioxide gas stream is generated by a gas reformer that forms a secondary hydrogen gas stream from a hydrocarbon source.

11. A method as claimed in claim 10 when dependent on claim 9, wherein the temperature of step (i) and/or step (ii) is adjusted by using at least some of the heat generated by the gas reformer.

12. The method of claim 10 or 11, wherein the hydrocarbon source is natural gas.

13. The method of any one of claims 1-12, further comprising filtering the gaseous by-product to separate a waste hydrocarbon gas stream.

14. A method according to claim 13 when dependent on any of claims 10 to 12, wherein the waste hydrocarbon gas stream is used to supplement the hydrocarbon source.

15. The method of any of claims 10-14, wherein the first hydrogen stream supplements the secondary hydrogen stream.

16. A method according to any one of claims 1 to 9 wherein the first waste carbon dioxide gas stream is generated by a coal or gas fired power station.

17. The method of any one of claims 1-16, further comprising supplying water to step (i).

18. The method of any one of claims 1-17, further comprising collecting the biomass waste stream generated in step (i) and/or step (ii).

19. A method for generating a hydrogen stream from a carbon dioxide gas stream, the method comprising:

(i) mixing the first waste carbon dioxide gas stream with an algae source to form an organic feedstock;

(ii) processing the organic feedstock in a first biological decomposition step to produce a first biological decomposition product; and

(iii) processing the first biodecomposition product in a second biodecomposition step to produce hydrogen;

wherein, prior to step (iii), at least a portion of the first biological decomposition product is mixed with the algae source in step (i).

20. The method of claim 19, wherein the first biodegradation step is aerobic and the second biodegradation step is anaerobic.

21. A method as claimed in claim 19 or 20, wherein the method is otherwise as defined in any one of claims 1 to 18.

22. Hydrogen produced using the method of any one of claims 1-21.

23. A method of generating electricity, comprising:

a hydrogen stream is generated according to any of claims 1-21 and used as a fuel source in the power generation step.

24. The method of claim 23, wherein the generating step comprises passing the hydrogen gas stream through a fuel cell to generate electricity.

25. The method of claim 23, wherein the generating step comprises enriching a combustible fuel with the hydrogen stream to form a hydrogen-rich fuel and combusting the hydrogen-rich fuel to drive a generator.

26. A method according to any one of claims 23 to 25 wherein the first waste carbon dioxide gas stream is generated by a coal or gas fired power station.

27. A system for generating a hydrogen stream from a carbon dioxide gas stream, comprising:

a photosynthesis reactor configured to convert the first waste carbon dioxide gas stream into an organic feedstock using the algae source, the photosynthesis reactor having an inlet for receiving the carbon dioxide gas stream and an organic feedstock outlet; and

a biological decomposition reactor comprising an inlet in communication with the organic feedstock outlet for receiving the organic feedstock, the biological decomposition reactor configured to convert the organic feedstock from the photosynthesis reactor into the hydrogen gas stream using organisms.

28. The system of claim 27, further comprising a hydrogen storage vessel in fluid communication with the biological decomposition reactor for receiving and storing the hydrogen gas stream generated in the biological decomposition reactor.

29. The system of claim 27 or 28, further comprising an auxiliary carbon dioxide supply line for transferring carbon dioxide generated in the biological decomposition reactor to the photosynthesis reactor, the auxiliary carbon dioxide supply line including a filter for filtering gases other than carbon dioxide.

30. The system of any one of claims 27-29, further comprising one or more heat exchangers configured to heat each of the photosynthesis reactor and the biodegradation reactor.

31. The system of any one of claims 27-30, further comprising a gas reformer for converting a hydrocarbon to a second hydrogen gas stream and the first spent carbon dioxide gas stream, wherein:

the second hydrogen stream is in fluid communication with the hydrogen storage vessel, and

the first waste carbon dioxide gas stream is in fluid communication with the photosynthesis reactor.

32. The system of claim 31 when dependent on claim 30, wherein the heat exchanger is configured to transfer heat generated by the gas reformer to the photosynthesis reactor and/or the biodegradation reactor.

33. The system of claim 31 or 32, further comprising an auxiliary hydrocarbon feed line connecting the biological decomposition reactor with the gas reformer for transferring hydrocarbons produced in the biological decomposition reactor to the gas reformer, the auxiliary hydrocarbon supply line comprising a filter for filtering out gases other than hydrocarbons.

34. The system of any one of claims 27-30, further comprising a combustion chamber in fluid communication with and upstream of the photosynthesis reactor, the combustion chamber configured to combust a fuel source to generate the first waste carbon dioxide gas stream.

35. The system of any one of claims 27-34, wherein the photosynthesis reactor and/or the biodegradation reactor are disposed on a transportable structure.

36. The system of any one of claims 27-35, further comprising a water supply for supplying water to the photosynthesis reactor and/or the biodegradation reactor.

37. The system of any one of claims 27-33, wherein the photosynthesis reactor and/or the biodegradation reactor each comprise a plurality of reactors.

38. The system of any one of claims 27-37, further comprising a transfer line for transferring at least a portion of the products formed in the biodegradation reactor to the photosynthesis reactor.

39. The system of any one of claims 27-38, further comprising a photosynthesis antifoaming agent configured to prevent foaming in the photosynthesis reactor and/or a biodegradation antifoaming agent configured to prevent foaming in the biodegradation reactor.

40. The system of any one of claims 27-39, further comprising a controller for controlling the photosynthesis reactor and/or the biodegradation reactor.

41. The system of any one of claims 27-40, further comprising an air supply for supplying air to the biological decomposition reactor.

42. The system of claim 41, wherein the air supply includes a biological filter for filtering biological material from the air supplied by the air supply.

43. Use of the system of any one of claims 27-42 to generate hydrogen.

44. A hydrogen powered vehicle gas station comprising the system of any one of claims 27-42.

Technical Field

The present disclosure relates to the use of a bioreactor to convert carbon dioxide to hydrogen.

Background

Lithium and hydrogen technology is competing to determine the future of electric vehicles. The limitations of lithium are vehicle range and charge time, and the challenges associated with hydrogen are the high cost of fuel, transportation and storage.

Both technologies are seemingly "green" in that running vehicles do not emit carbon dioxide. However, both hydrogen-fueled and lithium-fueled electric vehicles require fuel sources that sometimes result in greenhouse gas emissions.

Lithium batteries have become the leading technology in the electric vehicle industry. Nevertheless, conventional internal combustion engines are still more cost effective and convenient, especially for long haul transportation. Therefore, no matter what technology is adopted, the electric automobile is still a profitable market, and the automobile market cannot be completely subverted. The technical potential for cost-effective fuel cells is enormous, as many world-leading countries wish to phase out internal combustion engines in the middle. Since the current production price of hydrogen is too high to support large-scale use in electric vehicles, there is a need to provide hydrogen at a more cost-effective level.

In this regard, hydrogen "pump out" prices must be comparable to gasoline for hydrogen powered vehicles to become mainstream. For example, a Toyota Mirai driving 500 kilometers requires about 5 kilograms of hydrogen. An equivalent gasoline powered passenger vehicle would require about 40 liters of gasoline to travel the same distance. Assuming that the price of gasoline is between $ 1.00 and $ 1.25 per liter, the cost for this trip is between $ 40 and $ 50. In order for hydrogen-fueled yota Mirai to be price competitive within the same distance, the retail price of hydrogen needs to be between $ 8 and $ 10 per kilogram. However, consumers have not been able to obtain such hydrogen prices.

One problem with current hydrogen production is that a large portion (i.e., > 90%) of the hydrogen comes from hydrocarbons. Migration to hydrogen economy for hydrogen production from hydrocarbons has no reason to mitigate the effects of greenhouse gas production.

Another method of generating hydrogen is to electrolyze water. However, water splitting is not long-term feasible for a variety of reasons. For example, to achieve a hydrogen production rate of 500kg per day requires large equipment, availability of real estate is challenging, and capital costs are very expensive. The energy demand per unit of hydrogen produced is high, which can be offset by the use of solar energy, which is only available during the day and may not be regular. Therefore, a large amount of buffer storage is required to provide a viable solution, which increases capital costs. The overall production of hydrogen from water cracking is physically limited and is unlikely to reach a level where unit costs (including capital recovery) are always below the target price.

Hydrogen can also be produced by in situ steam methane reforming (grid gas). Steam reforming requires temperatures between 700 ℃ and 1000 ℃ and is energy intensive. Steam reforming produces much higher hydrogen yields than water cracking. However, small steam reformers using supply grid gas face problems. Supply grid gas contains a mixture of methane, butane, and ethane gases, where steam reforming is typically performed using only methane, and supply grid gas at a retail location is typically more expensive than methane in a Liquefied Natural Gas (LNG) production facility. Steam reforming also produces about 9 kg of carbon dioxide for every kg of hydrogen produced. Without carbon capture and storage solutions, steam reforming is not environmentally feasible when seeking to move to hydrogen economy.

The direct conversion of methane and other hydrocarbons to pure hydrogen with microorganisms remains a challenge on a large scale where efficiency is a determining factor. For example, bacterial species such as the saccharolytic pyrolytic cellulose (Caldicellulosriptor saccharolyticus) are known to convert methane in decaying organic matter to hydrogen. However, this direct conversion is not as efficient as converting methane from the supply grid gas to hydrogen by steam reforming. Furthermore, the production of carbon dioxide remains an unsolved problem for bacteria to convert supply net gas to hydrogen if there is no surrounding biomass.

Hybrid systems involving conventional chemical processes (steam reforming) can also be used to generate hydrogen. In these hybrid systems, carbon dioxide generated during steam reforming is captured and processed into organic components for treatment with microbial algae. However, while hybrid systems do provide a low cost carbon storage solution, they do not alleviate the problem of carbon dioxide generation, nor do they address the cost equation for small scale steam reforming of supply grid gases.

It will be understood that, for any prior art publication or reference referred to herein, such reference does not constitute an admission that the publication forms part of the common general knowledge in the art in australia or any other country.

Summary of The Invention

A first aspect of the disclosure provides a method of generating a hydrogen stream from a carbon dioxide gas stream. The method comprises the following steps: (i) the first waste carbon dioxide gas stream is converted to an organic feedstock using an algae source in a photosynthesis step. The method further comprises the following steps: (ii) the organisms are used in the biological decomposition step to convert the organic feedstock into a hydrogen gas stream and gaseous by-products. One embodiment may also include collecting the hydrogen stream.

The term "algal source" as used herein refers to one or more species of algae capable of photosynthetic conversion of carbon dioxide to organic feedstock. The term "organic feedstock" as used herein refers to a feedstock having organic matter, such as biomass, which may include simple and complex carbohydrates, such as simple and complex sugars, biopolymers, such as exopolysaccharides, algae debris and photosynthesis byproducts. The organic feedstock may also include materials used during the photosynthesis step, such as materials and reagents present in the culture medium for the photosynthetic conversion of carbon dioxide to organic feedstock. As used herein, the term "biodegrading" refers to the use of one or more organisms in one or more biological processes to convert organic feedstocks into other forms, including hydrogen.

The carbon dioxide gas stream may be generated by combusting the hydrocarbon, for example in a coal or gas fired power station, or converting the hydrocarbon to other gases including carbon dioxide in steam reforming. The disclosed process can provide efficiency savings by separating, counter-wisely, the conversion of, for example, methane (i.e., hydrocarbons) to hydrogen into two separate steps. An advantage of the disclosed process may be that spent carbon dioxide, such as carbon dioxide generated by an industrial process, may be converted to hydrogen. Thus, the method may be used as a means of "scavenging" or removing carbon dioxide from the atmosphere or from carbon dioxide production activities. The disclosed methods may be used in place of carbon dioxide sequestration, such as pumping and storing carbon dioxide in a geological formation. An additional advantage of the disclosed method over existing carbon dioxide sequestration techniques may be that the method also produces hydrogen as a renewable gas source.

The method can also include collecting the gaseous byproducts and filtering the gaseous byproducts to separate a second waste carbon dioxide gas stream. The process may further comprise transferring the second spent carbon dioxide stream to step (i). The first and second waste carbon dioxide gas streams may be combined. In one embodiment, step (i) may be carried out in a microbial reactor equipped with a photon source. The algae source may comprise algae in the class Chlorophyceae (Chlorophyceae) and/or Coccomyyceae (Trebouxiophyceae). The algae source may be a green plant. The algae species may be part of the genus Chlorella (Chlorella). In one embodiment, the algal species may be Chlorella (Chlorella vulgaris).

Step (ii) may comprise an aerobic biodegradation step and an anaerobic biodegradation step. The aerobic biological decomposition step may be performed before the anaerobic biological decomposition step. In one embodiment, at least a portion of the products of the aerobic biological decomposition step may be mixed, e.g. recycled, with the algae source in step (i) before being passed to the anaerobic biological decomposition step. In one embodiment, at least a portion of the products of the aerobic biological decomposition step are mixed with the algae source in step (i) as a collective "feed production stage" of the anaerobic biological decomposition step.

In one embodiment, step (ii) may be carried out in one or more biological decomposition reactors. For example, each biological decomposition reactor can include an aerobic reactor and an anaerobic reactor. The biological decomposition reactor may comprise one or more bacterial species. The bacterial species may belong to the class Clostridia (Clostridia), gamma proteobacteria (Gammaproteobacteria), Bacilli (Bacilli), Cocci (Cocci) and/or beta proteobacteria (Betaproteobacteria). The bacterial species may be gram-positive and/or catalase-positive bacteria. The bacterial species may comprise gram-negative bacteria. The bacterial species may be part of the genus Bacillus (Bacillus). In one embodiment, the bacterial species may comprise Bacillus subtilis. The bacterial species may be part of the class gammophytes. The bacterial species may be part of the genus Klebsiella (Klebsiella). In one embodiment, the aerobic biodegradation reactor may comprise gamma-proteobacteria and the anaerobic biodegradation reactor may comprise Enterobacter aerogenes (Enterobacter aeogenenes).

The method may further comprise adjusting the temperature of step (i) and/or step (ii), for example with a heat source. For example, both steps (i) and (ii) may be maintained at about 35 ℃. The specific temperature of the photosynthesis step and/or the biological decomposition step may be determined and adjusted by the algae sources and/or bacteria used in these steps to facilitate the algae sources and/or bacteria used in these steps.

The first waste carbon dioxide stream may be generated by a gas reforming step (e.g. by a steam reformer) which forms a secondary hydrogen gas stream from a hydrocarbon source. The heat source for adjusting the temperature of step (i) and/or step (ii) may be provided by the heat generated by the steam reformer. The hydrocarbon source may be natural gas, such as methane.

The gas reformer generates hydrogen and carbon dioxide. The disclosed method can be used to replenish hydrogen generated by the gas reformer (i.e., to provide a secondary hydrogen stream) when the first waste carbon dioxide gas stream is formed by the gas reformer. When using a gas reformer, the hydrogen production from the gas reformer can be increased from 40% to 65% per unit volume of natural gas consumed using at least some embodiments of the present disclosure.

The method may further include filtering the gaseous by-product to separate a waste hydrocarbon gas stream. The waste hydrocarbon gas stream may be used to supplement the hydrocarbon source. In one embodiment, the hydrogen stream and the secondary hydrogen stream may be combined. The secondary hydrogen stream may produce a larger volume of hydrogen gas than the (primary) hydrogen stream. The method may further comprise supplying water to step (i).

The method may further comprise collecting organic-rich material from step (ii). The organic-rich material may be a byproduct of a biological decomposition step that converts the organic feedstock into hydrogen. The organic-rich material can be used as a bio-fertilizer. In one embodiment, the process may be used to convert any source of carbon dioxide into methane, hydrogen, and biofertilizer.

A process for generating a hydrogen stream from a carbon dioxide gas stream is disclosed. The method includes (i) mixing a first waste carbon dioxide gas stream and an algae source to form an organic feedstock. The method also includes (ii) processing the organic feedstock in a first biodegradation step to produce first biodegradation products. The method further comprises the steps of (iii) processing the first biodecomposition product in a second biodecomposition step to produce hydrogen; wherein, prior to step (iii), at least a portion of the first biological decomposition product is mixed with the algae source in step (i). In one embodiment, the first biodegradation step may be aerobic and the second biodegradation step may be anaerobic. When the first biological decomposition step is aerobic, the combination of the first biological decomposition step and the algae source can be considered as a collective "feed production stage" of the anaerobic biological decomposition step. In one embodiment, other aspects of the method may be as described above.

Without being bound by theory, it is believed that mixing at least a portion of the first biodecomposition products with the algae source helps to (i) achieve higher carbon dioxide concentrations by increasing glucose production, and (ii) increase hydrogen production by preparing the biomass, including pH, for more efficient biological treatment in the second biodecomposition reactor. One embodiment may allow the refined biomass and glucose produced in the first biodegradation step to be recycled between the aerobic bacteria in the first biodegradation step and the aerobic algae in step (i). By diverting at least a portion of the first biobreakdown product and mixing it with the algae source in step (i), compounds other than hydrogen, such as methanol and other alcohols, can be produced instead of hydrogen. The organism used to generate hydrogen may be different from the organism used to produce other products such as alcohols.

One embodiment of the process can eliminate carbon dioxide emissions, reduce energy costs per kilogram of hydrogen produced, and increase the consumption of hydrogen units per unit of natural gas produced.

The present disclosure also provides hydrogen produced using the above method.

The present disclosure also provides organic materials produced by the above methods.

The present disclosure also provides a method of generating power, comprising: a hydrogen stream as described above is generated and used as a fuel source in the power generation step.

The step of generating electricity may include passing hydrogen gas through a fuel cell to generate electricity. The step of generating power may include enriching the combustible fuel with hydrogen to form a hydrogen-enriched fuel. The hydrogen-rich fuel may be combusted to drive an electrical generator. The first waste carbon dioxide gas stream may be generated from a coal or gas fired power station.

The present disclosure also provides a system for generating a hydrogen stream from a carbon dioxide gas stream. The system includes a photosynthesis reactor configured to convert a first waste carbon dioxide gas stream into an organic feedstock using an algae source, the photosynthesis reactor having an inlet for receiving the carbon dioxide gas stream and an organic feedstock outlet. The system also includes a biological decomposition reactor including an inlet in communication with the organic feedstock outlet for receiving the organic feedstock, the biological decomposition reactor configured to convert the organic feedstock from the photosynthesis reactor into a hydrogen gas stream.

The system may also include a hydrogen storage vessel in fluid communication with the biological decomposition reactor for receiving and storing the hydrogen gas stream generated in the biological decomposition reactor. The system may further include an auxiliary carbon dioxide supply line for transferring carbon dioxide generated in the biological decomposition reactor to the photosynthesis reactor. The auxiliary carbon dioxide supply line may include a filter for filtering gases other than carbon dioxide. The system may further include one or more heat exchangers to heat each of the photosynthesis reactor and the biodegradation reactor.

In one embodiment, the system may further comprise a gas reformer for converting hydrocarbons into a second hydrogen gas stream and a first waste carbon dioxide gas stream. The second hydrogen stream can be in fluid communication with a hydrogen storage vessel. The first waste carbon dioxide gas stream may be in fluid communication with the photosynthesis reactor. The one or more heat exchangers may be configured to transfer heat generated by the gas reformer to the photosynthesis reactor and/or the biodegradation reactor.

In one embodiment, the system may further comprise an auxiliary hydrocarbon feed line connecting the biological decomposition reactor with the gas reformer for transferring hydrocarbons produced by the biological decomposition reactor to the gas reformer. The auxiliary hydrocarbon supply line may include a filter for filtering out gases other than hydrocarbons.

The system can also include a combustion chamber in fluid communication with and upstream of the photosynthesis reactor. The combustion chamber can be configured to combust a fuel source to generate a first waste carbon dioxide gas stream.

The photosynthesis reactor and/or the biodegradation reactor may be arranged on a transportable structure, for example in a standard transport container. The photosynthesis reactor and/or the biodegradation reactor may each be provided as a modular unit. The system can be scaled up or down by adding or subtracting appropriate units. The system may also include, for example, a water supply in fluid communication with the photosynthesis reactor and/or the biodegradation reactor. The photosynthesis reactor and/or the biodegradation reactor may comprise a plurality of reactors. The multiple reactors may be arranged in series or in parallel with each other.

In one embodiment, the system may further comprise a photosynthesis antifoaming agent configured to prevent foaming in the photosynthesis reactor and/or a biodegradation antifoaming agent configured to prevent foaming in the biodegradation reactor. The system may be provided with a recycler for recycling water and/or biomass between the photosynthesis reactor and the biodegradation reactor. The recycler may transport materials and nutrients around the system, for example to support algae and/or bacterial communities in the photosynthesis reactor and/or the biodegradation reactor. The water used in the recycler may be used as a transport medium for transporting substances around the system.

The system may further comprise a controller for controlling the photosynthesis reactor and/or the biodegradation reactor. The system may further comprise an air supply for supplying air to the biological decomposition reactor. The air supply means may comprise a biological filter for filtering biological substances from the air supplied to the biological decomposition reactor by the air supply means. Water from a water source may be supplied to the photosynthesis reactor.

In one embodiment, the present disclosure also provides for the use of the above system to generate hydrogen.

In one embodiment, the present disclosure also provides a hydrogen powered vehicle gas station including the above system.

Brief description of the drawings

Embodiments will now be described, by way of example only, with reference to the accompanying non-limiting drawings.

Fig. 1 shows a schematic diagram of a system for generating hydrogen, according to one embodiment of the present disclosure.

Fig. 2 shows a schematic diagram of a system for generating hydrogen, according to another embodiment of the present disclosure.

Fig. 3 shows a schematic view of an embodiment of a photosynthesis reactor.

Fig. 4 shows a schematic diagram of a system for generating hydrogen, according to another embodiment of the present disclosure.

Fig. 5 shows an embodiment of a photosynthesis reactor.

Fig. 6 shows a schematic diagram of a system for generating hydrogen, according to another embodiment of the present disclosure.

Fig. 7 shows a schematic diagram of a system for generating hydrogen, according to another embodiment of the present disclosure.

FIG. 8 shows a schematic diagram of a distribution system for generating hydrogen at multiple locations relative to a gas supply.

Fig. 9 shows a schematic diagram of a system for generating power according to one embodiment of the present disclosure.

Fig. 10 shows a schematic diagram of a system for generating power according to another embodiment of the present disclosure.

Fig. 11 shows a schematic diagram of a system for generating hydrogen, according to another embodiment of the present disclosure.

FIG. 12 shows a schematic view of one embodiment of a biological decomposition reactor.

Detailed Description

One embodiment of a system 10 for producing hydrogen is shown in fig. 1. The system 10 has a microbial reactor in the form of a photobioreactor 12 configured to utilize photosynthesis to convert carbon dioxide to organic feedstock. Organic feedstocks include simple and complex carbohydrates, such as simple and complex sugars, and biopolymers such as exopolysaccharides. In one embodiment, the organic feedstock produced by the photobioreactor 12 includes biomass and sugars derived from glucose and polysaccharides. In one embodiment, the organic feedstock comprises a mixture of different carbohydrates. The system 10 also has a carbon dioxide supply line 28 that feeds carbon dioxide from the carbon dioxide source 11 into the photobioreactor 12. The carbon dioxide supply line 28 may include a filter that filters gases other than carbon dioxide. The system 10 also includes a biological decomposition reactor 14.

The carbon dioxide delivered to photobioreactor 12 may be mixed with other gases, such as air. In one embodiment, the concentration of carbon dioxide delivered to photobioreactor 12 ranges up to about 50%. In one embodiment, the concentration of carbon dioxide delivered to photobioreactor 12 ranges from about 8% to about 20%. Carbon dioxide may be supplied to photobioreactor 12 at a rate of about 0.2 to about 0.8 VVM. In one embodiment, a mixing manifold (not shown) is provided to allow for adjustment of the carbon dioxide concentration in the waste carbon dioxide gas stream.

The photobioreactor 12 and the biodegradation reactor 14 are connected to each other by a conduit 30. Conduit 30 conveys organic feedstock from the organic feedstock outlet of photobioreactor 12 to the inlet of biodegrading reactor 14. The organic feedstock is provided as a solid, slurry, and/or liquid. In one embodiment, the organic feedstock is supplied to the biological decomposition reactor 14 in a solution supply. In one embodiment, conduit 30 has a pump or auger for pumping or transporting the organic feedstock from the photobioreactor 12 to the biodegradation reactor 14. The biological decomposition reactor 14 is arranged to convert organic feedstock into hydrogen. In one embodiment, a filter is provided at the photobioreactor 12 such that only organic feedstock is passed from the photobioreactor 12 to the biodegrading reactor 14. In one embodiment, only a portion of the organic feedstock produced in the photobioreactor 12 is transferred to the biodegradation reactor 14. For example, a portion of the organic material is retained as inoculum. In one embodiment, 60% of the organic feedstock produced in the photobioreactor 12 is transferred to the biodegradation reactor 14, and 40% of the organic feedstock is retained as inoculum for further use in the photobioreactor 12. Reactors 12 and 14 may be operated as batch, semi-batch, or continuous processes.

The hydrogen produced in the biological decomposition reactor 14 is transferred through conduit 24 to a hydrogen storage vessel in the form of a storage vessel (e.g., a tank) 16. Conduit 24 includes a pump 25 that pumps the generated hydrogen to storage vessel 16. The pump 25 may allow the storage vessel 16 to be pressurized. However, pump 25 is not required for all embodiments. It should be understood that the term "storage vessel" should be broadly construed to include any form of closed/closable vessel capable of storing hydrogen, and also includes materials capable of adsorbing (i.e., reversibly adsorbing) hydrogen, such as carbonaceous materials, metal-organic frameworks, and molecular sieves.

The desired hydrogen output determines the desired output of the photobioreactor 12. The desired output of the photobioreactor 12 will depend on the desired input rate of the organic feedstock into the biodegradation reactor 14.

Photobioreactor 12 is configured for photosynthetic conversion of carbon dioxide into organic feedstock. The specific reaction conditions of the photobioreactor 12 depend on the biochemical requirements of the organisms present in the photobioreactor 12. However, the organisms present in the photobioreactor 12 are typically phototrophic. Phototrophic organisms may include algae species and mosses, as well as phototrophic bacteria such as cyanobacteria and purple bacteria. It should be understood that cyanobacteria are sometimes considered algae species, and are also referred to as such in this disclosure. In one embodiment, the photobioreactor comprises algae of the class chlorophyceae and/or Coccomyyceae. Cyanobacteria (Cyanophyceae) can include cyanobacteria and blue-green algae. In one embodiment, the class Chlorophyceae includes Aphyllophora obliquus (Acutodesmus obliquus), Scenedesmus tetragonolobus (Scenedesmus subspecies), Dunaliella salina (Dunaliella salina) and/or Scenedesmus obliquus. In one embodiment, the Coccomyxophyceae comprises Chlorella.

The specific time required to produce the organic feedstock may depend on the cell concentration and the algae species used as inoculum in the photobioreactor 12. When an algae species concentration threshold is reached, this may represent a trigger to transfer the resulting organic feedstock to the biodegradation reactor. For example, in one embodiment, when the density of the algae species is about 2X10⁷To about 2X10⁹CFU/ml, the organic feedstock is transferred from the photobioreactor 12 to the biodegrading reactor 14. In one embodiment, the photobioreactor 12 is operated for 48 hours to produce the organic feedstock. After 24 hours, the organic feedstock may have a 2x10⁷Algal species density of CFU/ml. It should be noted that the time to reach the final maximum cell density may depend on the inoculum cell concentration used to initially inoculate the photobioreactor.

The composition of the medium used in the photobioreactor 12 should depend on the phototrophic organism. Parameters such as culture medium, pH, salinity, nutrient requirements, required light dose rate, photosynthesis temperature, etc., should be adjusted according to the needs of the phototrophic organism. Generally, the temperature range for photosynthetic conversion of carbon dioxide to organic feedstock in the photobioreactor 12 should be from about 30 ℃ to about 40 ℃. The type of phototrophic organisms employed and the resulting organic feedstock produced by the phototrophic organisms can be selected according to the requirements of the biological decomposition reactor 14. In one embodiment, more than one type of phototrophic organism is used in the photobioreactor 12. Throughout this disclosure, the use of the term "phototrophic organism" includes mixtures of two or more specific phototrophic organisms.

The phototrophic object may be provided in the form of a concentrated solution that is transferred to the photobioreactor 12 and allowed to proliferate. In one embodiment, the phototrophic organisms may be provided in a dehydrated form for rehydration in the photobioreactor 12. The photobioreactor 12 may need to be cleaned periodically, whereby the culture medium and phototrophic organisms are replaced by a new batch of culture medium and phototrophic organisms. Unwanted by-products, such as biofilm, can be removed at this point. During the conversion of carbon dioxide to sugars, biomass is also produced.

The biodecomposition step carried out in the biodecomposition reactor 14 converts the organic feedstock produced in the photobioreactor 12 into hydrogen. The specific mechanism and biochemical requirements of the biodegradation step depend on the organisms present in the biodegradation reactor 14 and the type of organic feedstock produced by the photobioreactor 12. For example, in one embodiment, a fermentation process is used to convert the organic feedstock to hydrogen in the biological decomposition reactor 14. In one embodiment, the biological decomposition reactor 14 is operated under anaerobic and/or aerobic conditions. In one embodiment, the amount of hydrogen produced in the biological decomposition reactor 14 is 41 mol% based on the glucose equivalents in the organic feedstock.

Based on a photobioreactor having a volume of 0.5L, in one embodiment, 5.04 grams of hydrogen, 32.06 grams of carbon dioxide, and 18.49 grams of methane were produced every 24 hours using system 10. In one embodiment, about 10.08 grams of hydrogen may be produced from 1 liter of organic feedstock produced in the photobioreactor 12. The 0.5L photobioreactor can be scaled up or expanded according to the desired hydrogen output. Table 1 provides the mass balance of input and output based on a 0.5L volume photobioreactor 12. Surprisingly, the conversion efficiency of carbon dioxide to hydrogen is 64.3 mol% based on the amount of carbon dioxide input, which is 4-5 times the value based on known literature.

In one embodiment, water serves as a transport medium to transport organic feedstock (e.g., sugars and biomass) from the photobioreactor 12 to the biodegrading reactor 14 after the photosynthesis step in the photobioreactor 12. The use of water as a transport medium helps distribute carbon dioxide and nutrients in the photobioreactor 12. In one embodiment, the water transport medium is recirculated around the system 10, and the carbon dioxide in the system 10 may be mixed (e.g., emulsified) and recirculated between the photobioreactor 12 and the biodegradation reactor 14 until the carbon dioxide is converted to organic material or hydrogen. Similarly, some of the products formed in the biological decomposition reactor 14 may be recycled around the system 10. The water transport media may be filtered to filter out water soluble gases produced during use of the system 10. The term "aqueous transport medium" should be interpreted broadly to include any water-based solution. For example, the water transport medium may include reaction media, salts, buffers, nutrients, additives to promote favorable gas absorption, and the like.

The bacteria used in the biological decomposition reactor 14 may belong to the order thermoanaerobacteriales (Thermoanaerobacterales). Thermoanaerobactera bacteria may include Thermotoga maritima (Thermotoga maritima), Glycolyticus (Caldcellulosiror saccharolyticus), and Thermotoga exhii (Thermotoga elfii), but these bacteria are exemplary only and do not limit the scope of the present disclosure. In one embodiment, the bacteria used in the biological decomposition reactor 14 belong to the class clostridia. The clostridia can include Thermotoga maritima, Glycolytrolytic Pyrellulosa, and/or Thermotoga ehrlbergii. In one embodiment, the bacteria used in the biological decomposition reactor 14 belong to the class of gamma proteobacteria. The class of gamma proteobacteria may include Escherichia coli (Escherichia coli) and Pseudomonas syringae (Pseudomonas syringae). In one embodiment, the bacteria used in the biological decomposition reactor 14 belong to the class bacilli. The class Bacillus may include Bacillus licheniformis (Bacillus licheniformis), Bacillus amyloliquefaciens (Bacillus amyloliquefaciens), Bacillus subtilis (Bacillus subtilis), and/or Bacillus atrophaeus (Bacillus atrophaeus). In one embodiment, the bacteria used in the biological decomposition reactor 14 belong to the class coccidioidea. The coccoidea may include nonpathogenic variants of Staphylococcus fahrenheit (Staphylococcus aureus veneri). In one embodiment, the bacteria used in the biological decomposition reactor 14 belong to the class beta proteobacteria. Combinations of bacteria may be used in the biodegradation reactor 14, such as various combinations of bacteria in the clostridia, gamma proteobacteria, bacillus, cocci, and/or beta proteobacteria classes. Clostridia can include saccharolytic pyrolytic cellulose bacteria. The biological decomposition reactor 14 may also include rhizobia.

In one embodiment, the bacteria used in the biological decomposition reactor 14 use the sugars produced in the photobioreactor 12 as a food source and also extract the sugars in the relevant biomass without mechanical or chemical intervention. A water transport mechanism is used to facilitate the transfer of the sugars and biomass produced in the photobioreactor 12 to the biodegradation reactor 14. An advantage of using bacteria that utilize the sugars produced in photobioreactor 12 as a food source and extract the sugars in the relevant biomass without mechanical or chemical intervention is that biodegrading reactor 14 can provide energy savings because less equipment and/or processes are required to generate hydrogen.

In one embodiment, additional feedstocks, such as a raw biomass source and water, may be added to the biological decomposition reactor 14 to facilitate the production of hydrogen. When the photobioreactor 12 and/or the biodegradation reactor 14 are flushed, the biomass may be removed from the system. The photobioreactor 12 and the biodecomposition reactor 14 may be flushed simultaneously or at different times. Flushing of the photobioreactor 12 and/or the biodegradation reactor 14 allows fresh inoculum to be introduced into the photobioreactor 12 and/or the biodegradation reactor 14.

In one embodiment, the photobioreactor 12 has about 2 × 10¹¹Algae concentration of cells/ml, and the biodegradation reactor 14 has a concentration of about 1.5X10¹⁰Bacterial concentration of cells/ml. In one embodiment, the photobioreactor 12 and/or the biodecomposition reactor 14 may be operated at a pressure of 1atm to 5 atm.

The biological decomposition reactor 14 includes an outlet (not shown) for extracting organic-rich material produced during the conversion of the organic feedstock to hydrogen. The outlet for the organic-rich material may be the underflow (underflow) from the reactor 14. The organic-rich material can be used as a bio-fertilizer and sold as a separate raw material. Revenue generated from the separate feedstocks may be used to supplement the operating costs of the system 10. In one embodiment, when system 10 is upgraded or purged with new species in photobioreactor 12 and/or biodegrading reactor 14, organic-rich material is extracted, and the extracted material is organic-rich material. In one embodiment, the organic-rich material may provide a biofertilizer. The organic-rich material extracted from the system 10 is then replaced by newly inoculated species such as microalgae and bacteria in the photobioreactor 12 and the biodecomposition reactor 14. The extraction of the organic-rich material may be performed periodically, for example, about every two to three weeks.

In one embodiment, the organic-rich material has the following composition:

potassium: 2.67 percent

Calcium: 4.77 percent

Magnesium: 0.74 percent

Copper: 20.26ppm

Manganese: 309.52ppm

Iron: 1ppm of

Zinc: 80ppm of

Aluminum: 1 percent of

Sulfur: 0.5 percent

Sodium: 2 percent of

Boron: 0.008 percent

Organic carbon: 23.3 percent of

Carbon/nitrogen ratio: 24:1

Humidity (65 ℃ C.) 90%

Organic substances: 10 percent of

Total nitrogen: 0.96 percent

Density: 1.1g/cm³

In use, the biological decomposition reactor 14 produces hydrogen and waste carbon dioxide and/or waste hydrocarbons. The relative amounts of hydrogen, carbon dioxide and hydrocarbons produced in the biological decomposition reactor 14 generally depend on the conditions of the biological decomposition reactor. Because the photobioreactor 12 uses carbon dioxide as a feed, the biological decomposition reactor 14 may be equipped with an auxiliary carbon dioxide supply line 32 that transfers any carbon dioxide generated by the biological decomposition reactor 14 to the photobioreactor 12 (i.e., a carbon dioxide recycle line). This means that carbon dioxide generated by the biological decomposition reactor 14 can be used as a feed to the photobioreactor 12. The auxiliary carbon dioxide supply line 32 may help to increase the efficiency of the system 10, as greater hydrogen production may be achieved per unit of carbon dioxide delivered to the system through the carbon dioxide supply line 28.

The auxiliary carbon dioxide supply line 32 may be connected to the biological decomposition reactor 14, or the auxiliary carbon dioxide supply line 32 may be a branch of the conduit 24. In either configuration, the auxiliary carbon dioxide supply line 32 is equipped with a filter 33, such as a membrane filter, for filtering carbon dioxide gas from other gases such as hydrogen and hydrocarbons.

The photosynthesis heat exchanger 18 is in thermal communication with the photobioreactor 12 and the biodegradation heat exchanger 20 is in thermal communication with the biodegradation reactor 14. Heat exchangers 18 and 20 are connected to heat source 17 to supply heat to reactors 12 and 14. In fig. 1, the heat exchangers 18 and 20 are connected in parallel to the heat source 17, but the heat exchangers 18 and 20 may alternatively be connected in series.

In another embodiment, as best shown in FIG. 2, the water supply 21 is in fluid communication with the photobioreactor 12 and the photosynthesis heat exchanger 18 is in thermal communication with the water supply 21. This arrangement means that heat supplied to the photobioreactor 12 is transferred to the biodegradation reactor 14 by means of the passage of organic feedstock from the photobioreactor 12 to the biodegradation reactor 14. However, the embodiment shown in fig. 2 may also include a biodegradation heat exchanger 20. In the embodiment shown in fig. 2, the water supply 21 may comprise a mist generator for generating a mist of water from the water supply. The photosynthesis heat exchanger 18 may be in thermal communication with the mist generator.

In a variant of the embodiment of fig. 2, the water supply 21 is not in thermal communication with the heat exchanger 18, but the heat exchanger 18 is only in thermal communication with the photobioreactor 12.

The water supply 21 may have two water supply paths, one leading directly to the photobioreactor 12 and the other leading to the carbon dioxide mixing chamber 40. Carbon dioxide mixing chamber 40 receives carbon dioxide, for example, from carbon dioxide supply line 28 to form a carbon dioxide-rich solution, which is then delivered to photobioreactor 12. In one embodiment, the mixing chamber 40 forms an emulsion of carbon dioxide and water.

Typically, heat exchangers 18 and 20 will heat their respective reactors to maintain the reactors at a desired temperature. Typically, reactors 12 and 14 are maintained at a temperature in the range of about 30 ℃ to about 40 ℃. However, if reactors 12 and/or 14 include extreme microorganisms, the operating temperature may exceed 40 ℃, such as greater than 80 ℃. It should also be appreciated that heat exchangers 18 and 20 may also be operated to cool their respective reactors. Alternatively or additionally, the photobioreactor 12 may be in thermal communication with the biodegradation reactor 14 to transfer heat between the reactors 12 and 14, for example if one reactor requires continuous cooling and the other reactor requires continuous heating.

The photobioreactor 12 and the biodegradation reactor 14 are each depicted in fig. 1 and 2 as a single reactor, but in one embodiment, the photobioreactor 12 and/or the biodegradation reactor 14 may comprise a plurality of reactors. For example, FIG. 3 shows an embodiment in which the photobioreactor 12 has six reactors 12a-12 f. The reactors 12a-12f are connected in parallel. A gas manifold 39 connects the carbon dioxide supply line 28 to the reactors 12a-12 f. An algae manifold 41 connects the algae supply line 29 to the reactors 12a-12 f. The reactors 12a-12f are arranged for counter-current flow of carbon dioxide and algae material. In a variation of the embodiment of FIG. 3, reactors 12a-12f are connected in series.

An outlet gas line 31 is provided to allow excess gas to be removed from the reactors 12a-12 f. If the excess gas includes carbon dioxide, the excess gas may be reintroduced into the carbon dioxide supply line 28. When reactors 12a-12f are connected in series, the carbon dioxide and algae flows may be co-current or counter-current. Fig. 3 is merely exemplary, and embodiments of the photobioreactor 12 including multiple reactors may also be applicable to the biodegradation reactor 14. In one embodiment, each of the plurality of reactors is a modular unit. To increase the output of the system 10, additional modular units may be added to the respective reactors. Another advantage of the modular reactor unit is that one unit can be shut down, e.g., for maintenance, without having to completely shut down the system 10. In one embodiment, the photobioreactor 12 has six modular reactors and the biodegradation reactor 14 has six modular reactors.

An example of a modular photobioreactor (i.e., photosynthesis reactor) is shown in fig. 5. The modular photobioreactor 200 is a hollow tube 202, equipped with a light source in the form of a lamp 204 in the inner space of the tube 202. Reactor 200 has a capacity of about 1,200L. The power source 206 is connected to the lamp 204. The reactor 200 may have a plurality of lamps 204. The lamp 204 may emit visible and/or UV light. The hollow tube 202 in use is filled with a reaction medium 212 comprising an algae source. The reactor 200 has a gas inlet 208 mounted near the in-use bottom end of the hollow tube 202. The gas inlet 208 is used to introduce carbon dioxide into the hollow tube 202. The input line 210 is located near the in-use top end of the hollow tube 202. Input line 210 is used to add an algae source, reaction medium, buffers, pH adjusters, etc. to the hollow tube 202. Reactor 200 also has an outlet (not shown) for extracting organic feedstock produced by the photosynthetic conversion of carbon dioxide. The lamp 204 may be powered using a renewable energy source.

In one embodiment, the system 10 is provided with a photovoltaic element and associated battery system that can be used to power the light source 204. In one variant, the light source is omitted and daylight is used as the light source. In another variation, daylight is utilized as the light source during the day and the lamp 204 is utilized as the light source during the night to allow the photobioreactor to operate continuously.

Returning to fig. 1 and 2, the biological decomposition reactor 14 is connected to an air supply device 13. In one embodiment, the air supply device is a compressor. The air supply 13 may be equipped with a biological filter for filtering biological material from the supplied air. The air supplied by the air supply means 13 to the bio-decomposition reactor 14 helps the bacteria to drive the conversion of the organic raw material produced by the photo bioreactor 12 into hydrogen.

During the photosynthesis step in the photobioreactor 12 and the biodegradation step in the biodegradation reactor 14, there may be an accumulation of dissolved organic matter. The dissolved organic material has the potential to act as a surfactant and create foam. The generation of foam in each of reactors 12 and 14 reduces the ability of system 10 to convert carbon dioxide to hydrogen. To address this issue, in one embodiment (not shown), each of the photobioreactor 12 and the biodegradation reactor 14 also includes an anti-foaming agent that prevents foam from building up in the reactors 12 and 14.

In one embodiment, the photobioreactor 12 and the biodegradation reactor 14 each include a number of sensors, including a pH sensor, a temperature sensor, a reactor level sensor (reactor level sensor), and sensors that monitor the raw material production of the photobioreactor 12 and the gas production of the biodegradation reactor 14. In one embodiment, reactors 12 and 14 are equipped with rotameters that monitor the flow of gas into the reactors. The system 10 also includes a control system (not shown) that receives information from the various sensors. The control system can adjust parameters such as reactor temperature, algae and bacteria loading rates, and pH to optimize reaction conditions for most efficient hydrogen generation. Typically, each supply line, such as auxiliary carbon dioxide supply line 32 and conduits 28, 30 and 24, is equipped with valves that can be operated and controlled by the control system to control the flow of the various components around system 10. The control system may also include a data logger.

Fig. 11 shows an embodiment in which a return line (return line)50 connects the photobioreactor 12 and the biological decomposition reactor 14. Return line 50 allows at least a portion of the products in the biological decomposition reactor 14 to be diverted (i.e., recycled) back to the photobioreactor 12. Subjecting the products in the biological decomposition reactor 14 to further algal treatment in the photobioreactor 12 may help improve the conversion of carbon dioxide to hydrogen by making more organic feedstock available for conversion to hydrogen by the biological processes of the system 10.

In one embodiment, the biological decomposition reactor 14 has more than one reactor. As best shown in fig. 12, one embodiment of the biological decomposition reactor 14 has a first reactor 14a and a second reactor 14 b. Each of reactors 14a and 14b may have different reactor conditions. For example, reactors 14a and 14b may have different bacterial species to perform the first and second biodegradation processes. In one embodiment, one of reactors 14a and 14b is an aerobic reactor and the other is an anaerobic reactor. In one embodiment, reactor 14a is an aerobic reactor and reactor 14b is an anaerobic reactor. When two or more biological decomposition reactors are used, the reaction conditions in each reactor may be operated independently of each other.

Return line 50 may also be used when two or more biological decomposition reactors are used. For example, return line 50 can be connected to reactor 14a and/or 14 b. In one embodiment, return line 50 connects aerobic reactor (e.g., 14a) and photosynthesis reactor 12. This arrangement can be considered as a collective "feed production phase" of the anaerobic biological decomposition step. When an aerobic reactor is used, the reactor may be provided with an air supply (e.g. 13) to provide an air supply. In one embodiment, the aerobic reactor 14a is operated for 24 hours and the anaerobic reactor 14b is operated for 48 hours.

Although two reactors 14a and 14b are shown in fig. 12, in one embodiment, a single reactor may be used to perform different biological decomposition processes. For example, in one embodiment, a single reactor may be provided such that aerobic biological decomposition is first performed, and then reactor conditions are changed (e.g., oxygen/air evacuation) to perform anaerobic biological decomposition, or vice versa.

One advantage of the system 10 is that it can be used to remove carbon dioxide emissions from industrial processes, such as emissions from natural gas liquefaction, and can produce hydrogen. The production of hydrogen while consuming carbon dioxide, rather than sequestration of carbon dioxide, may help eliminate the need for geological formations required to sequester carbon dioxide. Further, the system 10 can scale up or down as needed depending on the amount of carbon dioxide that needs to be treated, and carbon dioxide sequestration is generally only feasible for large amounts of carbon dioxide.

Another embodiment of the system 100 is shown in fig. 4. System 100 is similar to system 10 except that carbon dioxide source 11 is a waste carbon dioxide gas stream generated by gas reformer 22. The gas reformer 22 converts a hydrocarbon source 26, such as methane or pipeline natural gas, to hydrogen via steam formation. A byproduct of steam reforming is carbon dioxide. In the embodiment of FIG. 4, the carbon dioxide byproduct is collected and transferred from the gas reformer 22 to the photobioreactor 12 via carbon dioxide supply line 28. In order to separate the carbon dioxide in the supply line 28 from other gases generated by the gas reformer 22, such as carbon monoxide, steam and hydrogen, a gas filter 29 may be provided on the carbon dioxide supply line 28.

The hydrogen produced by the gas reformer 22 is collected and passed through conduit 36 into the storage vessel 16. The conduit 36 may be provided with a filter 37 to remove any contaminants from the hydrogen gas stream. In one embodiment, the biological decomposition reactor 14 also produces hydrocarbons when the organic feedstock from the photobioreactor 12 is converted to hydrogen. An auxiliary hydrocarbon feed line 34 connects the biological decomposition reactor 14 with the gas reformer 22 for conveying hydrocarbons produced by the biological decomposition reactor 14 to the gas reformer 22. In one embodiment, auxiliary hydrocarbon supply line 34 is equipped with a filter 35 for purifying hydrocarbons produced by the biological decomposition reactor 14 prior to delivery to the reformer 22.

Supplying the gas reformer 22 with the hydrocarbons produced by the biological decomposition reactor 14 and also supplying the photobioreactor 12 with the carbon dioxide produced by the biological decomposition reactor 14 may help to increase the amount of hydrogen produced per unit of hydrocarbon (e.g., source 26) from about 40% to about 65%, which represents an increase in the amount of hydrogen produced by about 63%.

In one embodiment, supply lines 32 and 34 and conduit 24 are connected to manifold 102, as shown in FIG. 6. Manifold 102 is connected to the gas outlet of the biological decomposition reactor 14. Manifold 102 is also equipped with a filter so that hydrogen, carbon dioxide and any hydrocarbons produced by the biological decomposition reactor 14 are filtered and passed through respective lines 24, 32 and 34. In the embodiments shown in fig. 4 and 6, the auxiliary hydrocarbon feed line 34 may instead connect the feed lines 27 to form a single supply of hydrocarbon, rather than having two hydrocarbon input lines into the reformer 22.

The gas reformer 22 is in thermal communication with the heat exchangers 18 and 20 such that heat generated by the gas reformer 22 is used to heat the reactors 12 and/or 14. Heating the reactors 12 and 14 with heat generated by the reformer 22 helps to reduce the energy requirements of the reactors 12 and 14.

In one embodiment, the system 10 and/or 100 is provided with an extraction system for extracting gas (e.g., hydrogen) generated in use of the system. An extraction system is typically in communication with the biological decomposition reactor 14 to extract the gases generated therein. The extraction system may apply reduced pressure to degas gases dissolved within the reaction medium in the biological decomposition reactor 14.

In one embodiment, systems 10 and/or 100 are placed on a structure such as a shipping container. The structure may be a portable structure. The structure may be modular. The different components of the system, such as the photobioreactor 12 and the biodegradation reactor 14, may be arranged in different configurations such that each reactor is provided as its own modular unit. This means that the systems 10 and/or 100 can be easily scaled up or down as needed by adding or subtracting modular units as needed, depending on the desired hydrogen output.

A schematic diagram of one embodiment of a process plant 300 for producing hydrogen is shown in FIG. 7 and is based on the system 100. The process plant 300 has a solar power generation system 302 for providing power to the system 100 to maintain a low overall demand for grid energy and to act as a solar fail-safe when grid energy is temporarily interrupted. In one embodiment, the fab bay 300 is installed within the footprint of two 20 foot shipping containers. In another embodiment of the plant 300, the system 100 is replaced with the system 10.

The system 100 (e.g., plant 300) may be utilized as a hydrogen powered vehicle fueling station. Supply network gas is available to most locations in densely populated areas and is used as the gas source for reformer 22. One advantage of using existing retail supply network gas networks and infrastructure to generate hydrogen is that the transportation of hydrogen to the fueling stations can be eliminated and the hydrogen can be produced on-site on demand. The system 100 may also reduce the need to store large amounts of hydrogen to meet anticipated demand. System 100 combines an existing retail gas infrastructure with a bioreactor located at a service station to generate hydrogen. The use of photobioreactor 12 and biodegrading reactor 14 to generate hydrogen from carbon dioxide generated from reformer 22 may allow for the use of smaller reformers because the hydrogen output per unit gas input to system 100 is increased by about 65%. Smaller reformers can reduce capital and operating costs and help reduce hydrogen costs.

FIG. 8 illustrates one embodiment of a distribution system 400 for generating hydrogen at various locations, such as a plurality of hydrogen-powered vehicle fueling stations. The system 400 has a supply network gas supply 402 connected to a plurality of systems 100 at different locations 406a-d via a gas network and infrastructure 404. Each of locations 406a-d may be a hydrogen powered vehicle fueling station. Depending on the hydrogen demand at each location 406a-d, each system 100 may be optimized to generate hydrogen at each location 406 a-d.

In one embodiment, the system 100 at each location 406a-d may have a capacity of about 14,400L with a total hydrogen output of about 500 kg/day. When the system 10 is used to capture carbon dioxide produced by an LNG plant, the system 10 may have a capacity of about 11,700,000L with a total hydrogen output of about 10,000 kg/day.

The embodiment depicted in the figures shows the photobioreactor 12 and the biodecomposition reactor 14 as separate reactors. However, in one embodiment, the photosynthetic conversion of carbon dioxide to organic feedstock and the biological decomposition of organic feedstock to hydrogen may occur in the same reactor, and thus the photobioreactor 12 and the biological decomposition reactor 14 are the same unit.

One embodiment of the disclosed method may use a higher concentration of carbon dioxide (8% -20%) than in air (0.0314%) and may require much less water mass (hydrogen source) for a given mass of hydrogen output. Furthermore, as reasonably anticipated by the inventors, one embodiment of the disclosed method, as compared to any of today's known technologies, can: up to 500-; up to 28 times as much hydrogen (kg) is produced per kg of carbon dioxide consumed; up to 51 times the consumption of carbon dioxide (kg) per kg of hydrogen produced; and produces 13% of the total available hydrogen in the biological system (compare 0.009%).

Fig. 9 illustrates one embodiment of a system 600 for generating electricity. The system 600 has a coal fired power plant 602. The flue gas of the power plant 602 comprises carbon dioxide. The flue gas of the power station 602 is in fluid communication with the photobioreactor 12 of the system 10 and serves as the first waste carbon dioxide gas stream. In one embodiment, a filter is disposed between the power plant 602 and the photobioreactor 12 to filter out gases other than carbon dioxide in the flue gas. As described above, the system 10 converts the first spent carbon dioxide stream to hydrogen for storage in the vessel 16. In system 600, hydrogen fuel cell 604 is coupled to container 16 via conduit 606. The hydrogen stored in the container 16 may be transferred to the fuel cell 604 through a conduit 606 to generate electricity therein. In one embodiment, vessel 16 and conduit 606 are omitted and hydrogen produced in the biological decomposition reactor 14 is transported directly to the fuel cell 604 through conduit 24. The power generated by the fuel cell 604 may be supplied to the power plant 602 for distribution or may be distributed independently of the power generated by the power plant 602. By utilizing carbon dioxide present in flue gas from the power station as a fuel source, the system 600 can facilitate extracting more energy from the unit of coal input to the power station 602. System 600 can also help reduce the amount of carbon dioxide emitted by coal-fired power stations.

Fig. 10 illustrates another embodiment of a system 700 for generating electricity. The system 700 includes a gas power plant 702. Gas-fired power plants may operate using hydrocarbons such as natural gas. The flue gas of the power plant 702 comprises carbon dioxide. The flue gas of the power plant 702 is in fluid communication with the photobioreactor 12 of the system 10 and serves as the first waste carbon dioxide gas stream. In one embodiment, a filter is disposed between the power plant 702 and the photobioreactor 12 to filter gases other than carbon dioxide. As described above, the system 10 converts the first spent carbon dioxide stream to hydrogen for storage in the vessel 16. The vessel 16 is connected to a power station 702 by a conduit 704. Conduit 704 allows hydrogen stored in vessel 16 to be transferred to power station 702 where it may be mixed with hydrocarbon gas to form a hydrogen-rich gas that is combusted in power station 702. The system 700 may also be optionally equipped with an auxiliary hydrocarbon supply line 706. Any hydrocarbons produced in the biological decomposition reactor 14, such as methane, may be transferred to the power plant 702 via conduit 706 and mixed with natural gas combusted in the power plant 702. The hydrogen and optional hydrocarbons produced by the system 10 are used to supplement the main gas input for combustion in the power plant 702. By utilizing carbon dioxide in flue gas from a power plant as a fuel source, the system 700 can facilitate extracting more energy from a unit of gas input to the power plant 702. The system 700 may also help reduce the amount of carbon dioxide emitted by the gas power plant.

Examples

Embodiments will now be described using non-limiting examples.

Example 1

An embodiment of the laboratory test is as follows.

Injecting 120L of culture medium solution and 5L of Chlorella inoculum into air and CO at flow rate of 0.5-1.0VVM₂And treated in the photosynthesis reactor for 4 days until the reactor had sufficient biomass refraction for circulation and removal. The photobioreactor was equipped with two 12V LEDs with blue and red wavelengths of 400-^-2s^-1。

A portion (60%) of the biomass produced in the photosynthesis reactor is transferred to a biological decomposition reactor for digestion of the biomass (e.g., sugars) into gases, including hydrogen. The remaining 40% of the biomass is stored for use as inoculum for the photosynthesis reactor or as a biofertilizer feedstock.

In the biological decomposition reactor, biomass was mixed with 15 liters of 2 × 10¹¹(cell/ml) bacillus subtilis inoculum together was placed in an aerobic system (aerobic region) of a bioreactor and atmospheric gas was introduced at 0.8VVM for 48 hours, after which the biodegrading reactor was transferred to an anaerobic system with anaerobic bacteria aerogenic bacteria (a. aerogens) at a concentration of 1.5x10¹⁰(cells/ml).

The biomass in the biological decomposition reactor is digested for 48 hours, the gases formed are removed by the exhaust system and separated by filtration intoRespective component (e.g. CO)₂Stream, H₂Stream, CH₄Stream) that are recycled or removed and stored depending on the process used to produce H₂The system of (2). After digestion, the liquid containing the digested nutrients, bacteria and water is reused as inoculum for the system or as a biofertilizer soil amendment.

Example 2

Injecting 120L of culture medium solution and 5L of Chlorella inoculum into air and CO at flow rate of 0.2-0.8VVM₂And used in the photosynthesis reactor for 48 hours until the reactor has sufficient biomass refraction for circulation and removal. The concentration of carbon dioxide ranges from 8 to 20 vol%. The photobioreactor was equipped with two 12V LEDs with blue and red wavelengths of 400-^-2s^-1。

A portion (60%) of the biomass produced in the photosynthesis reactor is transferred to a biological decomposition reactor for digestion of the biomass (e.g., sugars) into gases, including hydrogen. The biomass transferred to the biological decomposition reactor had a carbohydrate yield of about 78% and consisted of about 35% glucose equivalents and galactose variants. The remaining 40% of the biomass is stored for use as inoculum for the photosynthesis reactor or as a biofertilizer feedstock.

In the biological decomposition reactor, biomass was mixed with 15 liters of 2 × 10¹¹(cell/ml) bacillus subtilis inoculum is put into an aerobic system of a bioreactor together, atmospheric gas is introduced for 24 hours at 0.8VVM, and then the biological decomposition reactor is transferred to an anaerobic system with anaerobic bacteria aerogenic bacillus for 48 hours, wherein the concentration of aerogenic bacillus is 1.5x10¹⁰(cells per ml).

Example 3

Example 2 was repeated, but 8010L of medium and 335L of chlorella were incubated in the photosynthetic reactor for 48 hours. 60% of the biomass produced in the photobioreactor was transferred to an aerobic biodegradation reactor with 1000L of Bacillus subtilis, where it was incubated for 24 hours. After aerobic biodegradation, aerogenic biodegradation is carried out by aerogenic bacillus to produce 81 kg/day of hydrogen, 513 kg/day of carbon dioxide and 596 kg/day of methane.

It will be appreciated by those skilled in the art that many modifications can be made to the embodiments described above without departing from the spirit and scope of the disclosure. The above-described embodiments are merely exemplary and are not intended to limit the scope of the present disclosure.

In the claims which follow and in the preceding description, unless the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments.