WO2006130678A2 - Dual method of hydrogen production - Google Patents

Abstract

The present invention provides a dual method of hydrogen production, wherein organic feed material is heated with excess or diverted heat from a secondary hydrogen production method, thereby substantially deactivating or killing methanogens within the organic feed material. Hydrogen producing microorganisms contained or added to the organic feed material metabolize the organic feed material in a bioreactor to produce hydrogen in a primary hydrogen production method. As the methanogens are no longer substiantially present to convert produced hydrogen to methane, a biogas that contains hydrogen without substantial methane can be produced.

Description

DUAL METHOD OF HYDROGEN PRODUCTION

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority under 35 U.S.C. §119(e) to U.S.

Provisional Patent Application Serial No. 60/685,963, filed May 31, 2005, entitled "SEQUENTIAL METHOD OF HYDROGEN PRODUCTION"

FIELD OF THE INVENTION

[0002] The present invention relates generally to a combination method for concentrated production of hydrogen from hydrogen producing microorganism cultures. More particularly, the invention relates to a method that dually combines a primary hydrogen production method with a secondary hydrogen production method that is different than the primary hydrogen production method. The primary hydrogen production method uses heat or uses heat waste that is produced during typical usage of the secondary hydrogen production method, thereby reducing energy costs of the primary hydrogen production method and conserving energy.

BACKGROUND OF THE INVENTION

[0003] The production of hydrogen is an increasingly common and important procedure in the world today. Production of hydrogen in the U.S. alone currently amounts to about 3 billion cubic feet per year, with output likely to increase. Uses for the produced hydrogen are varied, ranging from uses in welding to production of hydrochloric acid. An increasingly important use of hydrogen relates to the production of alternative fuels for machinery such as motor vehicles. Successful use of hydrogen as an alternative fuel can provide substantial benefits to the world at large. This is important not only in that the hydrogen can be formed without dependence on the location of specific oils or other ground resources, but in that burning of hydrogen for fuel is atmospherically clean. Essentially, no carbon dioxide or greenhouse gasses are produced during the burning. Thus, production of hydrogen is an environmentally desirable goal. [0004] Creation of hydrogen from certain methods and apparatuses are generally known. For example, electrolysis, which generally involves the use of electricity to decompose water into hydrogen and oxygen, is a commonly used process. Significant energy, however, is required to produce the needed electricity to perform the process. Similarly, steam reforming is another expensive method requiring fossil fuels as an energy source. As could be readily understood, the environmental benefits of producing hydrogen are at least partially offset when using a process that uses pollution-causing fuels as an energy source for the production of hydrogen.

[0005] New methods of hydrogen generation are therefore needed. One possible method is to create hydrogen in a biological system by converting organic matter into hydrogen gas. The creation of a biogas that is substantially hydrogen can theoretically be achieved in a bioreactor, wherein hydrogen producing microorganisms and an organic feed material are held in an environment favorable to hydrogen production. Substantial and useful creation of hydrogen gas from micro-organisms, however, is problematic. The primary obstacle to sustained production of useful quantities of hydrogen by microorganisms has been the eventual stoppage of hydrogen production generally coinciding with the appearance of methane. This occurs when methanogenic microorganisms invades the bioreactor environment converting hydrogen to methane. This process occurs naturally in anaerobic environments such as marshes, swamps, and pond sediments. As the appearance of methanogens in a biological system has previously been largely inevitable, continuous production of hydrogen from hydrogen producing micro-organisms has been unsuccessful in the past.

[0006] Microbiologists have for many years known of organisms which generate hydrogen as a metabolic by-product. Two reviews of this body of knowledge are Kosaric and Lyng (1988) and Nandi and Sengupta (1998). Among the various organisms mentioned, the heterotrophic facultative anaerobes are of interest in this study, particularly those in the group known as the enteric microorganisms. Within this group are the mixed-acid fermenters, whose most well known member is Escherichia coli. While fermenting glucose, these micro-organisms split the glucose molecule forming two moles of pyruvate (Equation 1); an acetyl group is stripped from each pyruvate fragment leaving formic acid (Equation 2), which is then cleaved into equal amounts of carbon dioxide and hydrogen as shown in simplified form below (Equation 3).

Glucose → 2 Pyruvate (1)

2 Pyruvate + 2 Coenzyme A → 2 Acetyl-CoA + 2 HCOOH (2)

2 HCOOH → 2 H₂ + 2 CO₂ (3) [0007] Thus, during this process, one mole of glucose produces two moles of hydrogen gas. Also produced during the process are acetic and lactic acids, and minor amounts of succinic acid and ethanol. Other enteric microorganisms (the 2, 3 butanediol fermenters) use a different enzyme pathway which causes additional CO₂ generation resulting in a 6:1 ratio of carbon dioxide to hydrogen production (Madigan et al., 1997). After this process, the hydrogen is typically converted into methane by methanogens. [0008] There are many sources of waste organic matter which could serve as a substrate for this microbial process. One such material would be organic-rich industrial wastewaters, particularly sugar-rich waters, such as fruit and vegetable processing wastes. Other sources include agricultural residues and other organic wastes such as sewage and manures.

[0009] Electrolysis is generally a chemical process in which chemically bonded elements are separated by passing an electrical current through them. An important application of electrolysis is in the separation of water into hydrogen and oxygen by the equation 2H₂O → 2H₂ + O₂. This reaction can occur on a highly simplified level, for example, by running two leads from a typical battery into water held in a cup. In this instance, as electricity is passed from one lead to another, preferably with the aid of a water soluble electrolyte, hydrogen and oxygen bubbles can be seen bubbling up from the water.

[0010] In other industrial applications, electrolysis can create hydrogen on a larger scale. While electrolysis can occur at room temperature, doing so at an efficient level requires a high level of electrical energy. High temperature electrolysis is more efficient than traditional room-temperature because some of the energy is supplied as heat, which is cheaper than electricity, and because the electrolysis reaction is more efficient at higher temperatures. Indeed, at 2500⁰C, electrical input is unnecessary because water breaks down to hydrogen and oxygen through thermolysis. As such, temperatures are impractical, however; high temperature electrolysis systems operate at about 100 to 1000⁰C. At higher temperature operating rates, lower levels of energy are required.

[0011] Typical high temperature electrolysis conveys steam or super-heated water into an electrolytic cell. This may occur in combination with hydrogen, for example, at about a 50-50 ratio of steam to hydrogen. The water or steam is split in the cell such that, when split, oxygen passes through a membrane away from the hydrogen and un-split water or steam. If steam is used, the steam and hydrogen exits the cell with a greater amount of hydrogen than steam, which can be separated from the hydrogen by a condenser or other like process. In either case, there is never a 100% efficient conversion of the water or steam to hydrogen, resulting in left over heated steam, water and/or oxygen.

[0012] In other industrial applications, hydrogen is produced through other reactions that occur at increased temperature levels. Usually in these instances, for economic production, high temperatures are required to ensure rapid throughput and high conversion efficiencies. (Transport and the Hydrogen Economy, UIC Nuclear Issues Briefing Paper # 73, October 2005) For example, in an sulfur-iodine system, sulfuric acid is heated under high temperature (800-1000⁰C) and low pressure. The sulfuric acid breaks sown into water, oxygen and sulfur oxide, which combine with iodine to form 2HI and sulfuric acid. The 2HI reacts with water and sulfur dioxide to under temperatures of about 35O⁰C to produce hydrogen and sulfur dioxide. The net result of the equation is the same as electrolysis: 2H₂O ^→ 2H₂ + O₂. However, as not all compounds are converted, this process also results in heat or excess heat in the form of several solutions or gasses of elevated temperatures at elevated temperatures.

[0013] New types of hydrogen generation are therefore needed that produce substantial and useful levels of hydrogen in an inexpensive, environmentally sound method that additionally dually combine differing methods of hydrogen production.

SUMMARY OF THE INVENTION

[0014] Therefore, it is an object of the present invention to create a dual method of hydrogen production wherein hydrogen is produced in a primary process with hydrogen producing microorganisms by utilizing heat or heat waste from a hydrogen producing process such as electrolysis to deactivate or kill methanogens that would otherwise metabolize the produced hydrogen.

[0015] It is a further object of the invention to provide a method for dually producing hydrogen including the steps of performing a secondary hydrogen production method wherein hydrogen is produced from the one or a series of reactions under elevated temperatures to produce hydrogen and oxygen, the secondary hydrogen production method producing heated liquids or gases, heating organic feed material in a primary hydrogen production method with heat from the secondary hydrogen production method, wherein the organic feed material is conducive to the growth of hydrogen producing microorganisms, conveying the organic feed material into a bioreactor of the primary hydrogen production method, wherein the bioreactor is an anaerobic environment, and removing hydrogen from the bioreactor.

[0016] It is a further object of the invention to provide a method wherein a bioreactor is readily combinable and proximate with secondary hydrogen production methods that use elevated temperatures of varying types, the bioreactor utilizing heat or heat waste from the secondary hydrogen production method, wherein the hydrogen is not substantially converted to methane subsequent to production.

[0017] It is a further object of the invention to heat the organic feed material prior to entry into the bioreactor, wherein heating is achieved in any one or a multiplicity of upstream containers or passages, such that heating the organic feed material at temperatures of about 60 to 100⁰C kills or deactivates methanogens while leaving hydrogen producing microorganisms intact.

[0018] It is a further object of the invention to treat the organic feed material with one or a multiplicity of treatment steps, including aerating the organic feed material, diluting the organic feed material, inoculating the organic feed material with additional hydrogen producing microorganisms, or adding other chemical supplements. The treatment steps may occur in the bioreactor or further upstream the bioreactor. [0019] It is a further object of the invention to provide a method for dually producing hydrogen, including the steps of performing a secondary hydrogen production method wherein hydrogen is produced from electrolysis of water into hydrogen and oxygen, the secondary hydrogen production method producing heated liquids or gases, heating organic feed material in a primary hydrogen production method with heat from the secondary hydrogen production method, wherein the organic feed material is conducive to the growth of hydrogen producing microorganisms, conveying the organic feed material into a bioreactor of the primary hydrogen production method, wherein the bioreactor is an anaerobic environment, and removing hydrogen from the bioreactor. [0020] These and other objects of the present invention will become more readily apparent from the following detailed description and appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a plan view of a primary hydrogen production method proximate the secondary hydrogen production method.

[0022] Figure 2 is a side view of one embodiment of the bioreactor.

[0023] Figure 3 is a plan view the bioreactor.

[0024] Figure 4 is a plan view of a secondary hydrogen production method proximate the primary hydrogen production method.

[0025] Figure 5 is a plan view of a high temperature secondary hydrogen production method proximate the primary hydrogen production method.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0026] As used herein, the term "microorganisms" include microorganisms and substantially microscopic cellular organisms.

[0027] As used herein, the term "hydrogen producing microorganisms" includes microorganisms that metabolize an organic substrate in one or a series of reactions that ultimately form hydrogen as one of the end products.

[0028] As used herein, the term "methanogens" refers to microorganisms that metabolize hydrogen in one or a series of reactions that produce methane as one of the end products.

[0029] As used herein, the term "primary hydrogen production method" refers to a hydrogen producing process from hydrogen producing microorganisms in a bioreactor and related preparatory steps.

[0030] As used herein, the term "secondary hydrogen production method" refers to a hydrogen producing process other than a bioreactor hydrogen producing process wherein heat waste resultant from the dual hydrogen producing process is used in the primary hydrogen production method.

[0031] As used herein, the term "heat waste" refers to heat that is produced by dual hydrogen producing process that is otherwise not recycled into the sequential dual producing process such as excess heat or aqueous or gaseous compounds that have elevated temperatures, wherein some of the heat is diverted into another hydrogen producing process. [0032] A dual hydrogen producing method 100 in accordance with the present invention is shown in Figure 1, wherein an apparatus using primary hydrogen production method 96 is shown in detail. As shown in Figure 1, primary hydrogen production method 96 has a multiplicity of containers including bioreactor 10, heat exchanger 12, optional equalization tank 14 and reservoir 16. Method 100 further uses secondary hydrogen production apparatus 50 and passage 44 bridging primary hydrogen production method 96 and secondary hydrogen production method 98. Method 100 produces gas in bioreactor 10, wherein the produced gas contains hydrogen and does not substantially include any methane. The hydrogen containing gas is produced by the metabolism of an organic feed material by hydrogen producing microorganisms. [0033] In preferred embodiments, organic feed material is a sugar containing organic feed material. In further preferred embodiments, the organic feed material is industrial wastewater or effluent product that is produced during routine formation of fruit and/or vegetable juices, such as grape juice. In additional embodiments, wastewaters rich not only in sugars but also in protein and fats could be used, such as milk product wastes. The most complex potential source of energy for this process would be sewage-related wastes, such as municipal sewage sludge and animal manures. However, any feed containing organic material is usable.

[0034] Hydrogen producing microorganisms metabolize the sugars in the organic feed material under the reactions:

Glucose → 2 Pyruvate (1)

2 Pyruvate + 2 Coenzyme A → 2 Acetyl-CoA + 2 HCOOH . (2)

2 HCOOH → 2 H₂ + 2 CO₂ (3)

[0035] During this process, one mole of glucose produces two moles of hydrogen gas and carbon dioxide. In alternate embodiments, other organic feed materials include agricultural residues and other organic wastes such as sewage and manures. Typical hydrogen producing microorganisms are adept at metabolizing the high sugar organic waste into microorganism waste products. The wastewater may be further treated by aerating, diluting the solution with water or other dilutants, adding compounds that can control the pH of the solution or other treatment step. For example, the electrolyte contents (Na, K, Cl, Mg, Ca, etc.) of the organic feed material can be adjusted. Further, the solution may be supplemented with phosphorus (NaH₂PO₄) or yeast extract. [0036] Organic feed material provides a plentiful feeding ground for hydrogen producing microorganisms and is naturally infested with these microorganisms. While hydrogen producing microorganisms typically occur naturally in an organic feed material, the organic feed material is preferably further inoculated with hydrogen producing microorganisms in an inoculation step. In further preferred embodiments, the inoculation is an initial, one-time addition to bioreactor 10 at the beginning of the hydrogen production process. The initial inoculation provides enough hydrogen producing microorganisms to create sustained colonies of hydrogen producing microorganisms within the bioreactor. The sustained colonies allow the sustained production of hydrogen. Further inoculations of hydrogen producing microorganisms, however, may be added as desired. The added hydrogen producing microorganisms may include the same types of microorganisms that occur naturally in the organic feed material. In preferred embodiments, the hydrogen producing microorganisms, whether occurring naturally or added in an inoculation step, are preferably microorganisms that thrive in pH levels of about 3.5 to 6.0 and can survive in temperature of 60-100⁰F or, more preferably, 60-75°. These hydrogen producing microorganisms include, but are not limited to, Clostridium sporogenes, Bacillus licheniformis and Kleibsiella oxytoca. Hydrogen producing microorganisms can be obtained from a microorganismal culture lab or like source. Other hydrogen producing microorganisms or microorganisms known in the art, however, can be used within the spirit of the invention. The inoculation step can occur in bioreactor 10 or elsewhere in the apparatus, for example, recirculation system 58. [0037] In one embodiment of the invention, organic feed material is first contained in reservoir 16. Reservoir 16 is a container known in the art that can contain an organic feed material. The size, shape, and material of reservoir 16 can vary widely within the spirit of the invention. In one embodiment, reservoir 16 is one or a multiplicity of storage tanks that are adaptable to receive, hold and store the organic feed material when not in use, wherein the one or a multiplicity of storage tanks may be mobile. In preferred embodiments, reservoir 16 is a wastewater well that is adaptable to receive and contain wastewater and/or effluent from an industrial facility. In further preferred embodiments, reservoir 16 is adaptable to receive and contain wastewater that is effluent from a juice manufacturing industrial facility, such that the effluent held in the reservoir is a sugar rich juice sludge.

[0038] The organic feed material in reservoir 16 is thereafter conveyed throughout the system, such that the system is preferably a closed system of continuous movement. Conveyance of organic feed material can be achieved by any conveying means known in the art, for example, one or a multiplicity of pumps. The method uses a closed system, such that a few well placed conveying means can convey the organic feed material throughout the system, from reservoir 16 to optional equalization tank 14 to heat exchanger 12 to bioreactor 10 to outside of bioreactor 10. In preferred embodiments, organic feed material contained in reservoir 16 is conveyed into passage 22 with pump 28. Pump 28 is in operable relation to reservoir 16 such that it aids removal movement of organic feed material 16 into passage 22 at a desired, adjustable flow rate, wherein pump 28 can be any pump known in the art suitable for pumping liquids. In a preferred embodiment, pump 28 is a submersible sump pump.

[0039] The method may further include temporary deactivation of conveyance from reservoir 16 to equalization tank 14 or heat exchanger 12 if the pH levels of organic feed material in reservoir 16 exceeds a predetermined level. In this embodiment, reservoir 16 furthers include a low pH cutoff device 52, such that exiting movement into passage 22 of the organic feed material is ceased if the pH level of the organic feed material is outside of a desired range. The pH cutoff device 52 is a device known in the art operably related to reservoir 16 and pump 28. If the monitor detects a pH level of a solution in reservoir 16 out of range, the device ceases operation of pump 28. The pH cut off level in reservoir 16 is typically greater than the preferred pH of bioreactor 10. In preferred embodiments, the pH cutoff level is set between about 7 and 8 pH. The conveyance with pump 28 may resume when the pH level naturally adjusts through the addition of new organic feed material into reservoir 16 or by adjusting the pH through artificial means, such as those of pH controller 34. In alternate embodiments, particularly when reservoir 16 is not adapted to receive effluent from an industrial facility, the pH cutoff device is not used.

[0040] Passage 22 provides further entry access into equalization tank 14 or heat exchanger 12. Equalization tank is an optional intermediary container for holding organic feed material between reservoir 16 and heat exchanger 12. Equalization tank 14 provides an intermediary container that can help control the flow rates of organic feed material into heat exchanger 12 by providing a slower flow rate into passage 20 than the flow rate of organic feed material into the equalization tank through passage 22. An equalization tank is most useful when reservoir 16 received effluent from an industrial facility 50 such that it is difficult to control flow into reservoir 16. The equalization tank can be formed of any material suitable for holding and treating the organic feed material. In the present invention, equalization tank 14 is constructed of high density polyethylene materials. Other materials include, but are not limited to, metals or acrylics. Additionally, the size and shape of equalization tank 14 can vary widely within the spirit of the invention depending on throughput and output and location limitations. [0041] The method preferably further includes discontinuance of conveyance from equalization tank into heat exchanger 12 if the level of organic feed material in equalization tank 14 falls below a predetermined level. Low-level cut-off point device 56 ceases operation of pump 26 if organic feed material contained in equalization tank 14 falls below a predetermined level. This prevents air from being sucked by pump 26 into passage 20, thereby maintaining an anaerobic environment in bioreactor 10. Organic feed material can be removed through passage 20 or through passage 24. Passage 20 provides removal access from equalization tank 14 and entry access into heat exchanger 12. Passage 24 provides removal access from equalization tank 14 of solution back to reservoir 16, thereby preventing excessive levels of organic feed material from filling equalization tank 14. Passage 24 provides a removal system for excess organic feed material that exceeds the cut-off point of equalization tank 14. Both passage 20 and passage 24 may further be operably related to pumps to facilitate movement of the organic feed material. In alternate embodiments, equalization tank 14 is not used and organic feed material moves directly from reservoir 16 to heat exchanger 12. This is a preferred embodiment when the method is not used in conjunction with industrial facility 50 such that effluent from the industrial facility is directly captured in reservoir 16. If reservoir 16 is one or a multiplicity of storage tanks holding an organic feed material, equalization tank 14 may not be necessary. In these embodiments, passages connecting reservoir 16 and heat exchanger 12 are arranged accordingly.

[0042] The organic feed material is heated prior to conveyance into the bioreactor to deactivate or kill undesirable microorganisms, i.e., methanogens and non-hydrogen producers. The heating can occur anywhere upstream. In one embodiment, the heating is achieved in one or a multiplicity of heat exchangers 12, wherein the organic feed material is heated within the heat exchanger by liquids or gasses of elevated temperatures from secondary hydrogen production apparatus 50 conveyed through passage 44. Passage 44 may further be associated with a pump device to control flow rates. After exiting heat exchanger 12, gases or liquids originally conveyed through passage 44 may be discarded through an effluent pipe (not pictured) or recycled back into the secondary hydrogen production apparatus. Organic feed solution can be additionally heated at additional or alternate locations in the hydrogen production system. Passage 20 provides entry access to heat exchanger 12, wherein heat exchanger 12 is any apparatus known in the art that can contain and heat contents held within it. Passage 20 is preferably operably related to pump 26. Pump 26 aids the conveyance of solution from equalization tank 14 or reservoir 16 into heat exchanger 12 through passage 20, wherein pump 26 is any pump known in the art suitable for this purpose. In preferred embodiments, pump 26 is an air driven pump for ideal safety reasons, specifically the interest of avoiding creating sparks that could possible ignite hydrogen. However, motorized pumps are also found to be safe and are likewise usable.

[0043] A heating source for method 100 preferably is heat exchanger 12 that uses heat or heat waste from secondary hydrogen production method 98 to heat the organic feed material, wherein the heat exchanger is a heat exchanger known in the art. The heat waste may be transferred through passage 44. The heat exchanger can be a liquid phase- liquid phase or gas-phase/liquid phase as dictated by the phase of the heat waste. A typical liquid-liquid heat exchanger, for example, is a shell and tube heat exchanger which consists of a series of finned tubes, through which a first fluid runs. A second fluid runs over the finned tubes to be heated or cooled. Another type of heat exchanger is a plate heat exhanger, which directs flow through baffles so that fluids to be ehated and cooled are separated by plates with very large surface area.

[0044] To allow hydrogen producing microorganisms within the bioreactor 10 to metabolize the organic feed material and produce hydrogen without subsequent conversion of the hydrogen to methane by methanogens, methanogens contained within the organic feed material are substantially killed or deactivated. In preferred embodiments, the methanogens are substantially killed or deactivated prior to entry into the bioreactor. In further preferred embodiments, methanogens contained within the organic feed material are substantially killed or deactivated by being heated under elevated temperatures in heat exchanger 12. Methanogens are substantially killed or deactivated by elevated temperatures. Methanogens are generally deactivated when heated to temperatures of about 60-75⁰C for a period of at least 15 minutes. Additionally, methanogens are generally damaged or killed when heated to temperatures above about 9O⁰C for a period of at least 15 minutes. Heat exchanger 12 enables heating of the organic feed material to temperature of about 60-100⁰C in order to substantially deactivate or kill the methanogens while leaving any hydrogen producing microorganisms substantially functional. This effectively pasteurizes or sterilizes the contents of the organic feed material from active methanogens while leaving the hydrogen producing microorganisms intact, thus allowing the produced biogas to include hydrogen without subsequent conversion to methane. The size, shape and numbers of heat exchangers 12 can vary widely within the spirit of the invention depending on throughput and output required and location limitations. In preferred embodiments, retention time in heat exchanger 12 is at least 20 minutes. Retention time marks the average time any particular part of organic feed material is retained in heat exchanger 12.

[0045] Heat is captured from secondary hydrogen production method 98 and is used to partially or fully heat the organic feed material to the temperatures of about 60 to 100⁰C. The secondary hydrogen production method can include any hydrogen producing method wherein that includes heat. In preferred embodiments, the secondary hydrogen production method is a method that produces hydrogen with by separating H₂O into hydrogen or water in one or a series of reactions. In further preferred embodiments, the secondary hydrogen production method is an electrolyzer or a sulfur-iodine system. In one embodiment, a steam based high temperature electrolyzer is combined with the primary hydrogen production method 96 of the invention as shown in Figure 4. Electrolyzer 114 includes cell 102 having a cathode 104 and an anode 106, wherein applied electrical current 112 is applied to the cell. The cell may further include a membrane 108 as needed. Steam and hydrogen stream 110 is conveyed into cell 102, wherein the steam is heated at a temperature from about 100-1000⁰C. The amount of energy needed as a function of temperature is generally known in the art, as shown in Table 4. The thermal and electro forces will cause a portion of the water or steam to split, wherein oxygen will pass through ion conducting membrane 108 to the anode side and is removed on that side. A mixture of steam and hydrogen, including hydrogen newly formed from separation of the water, exits the cell on the cathode side with heated temperatures. The hydrogen can then be removed from the steam with a condenser. The condenser can function as heat exchanger 12 or can be a separate condenser that functions in tandem with heat exchanger 12. Either way, the heat exchanger 12 obtains heat from the steam that exits cell 102 and uses the heat to dually produce hydrogen in the primary hydrogen production method by elevate the temperature of organic feed material to about 6O tO lOO⁰C.

[0046] Alternatively, secondary hydrogen production method is a high temperature electro lyzer that uses heated water, as in Figure 5. Here, an electrical current is applied to cathode 116 and anode 118 under heated temperatures of about 100-1000⁰C, separating a portion of the heated water into oxygen and hydrogen. The oxygen migrates to the anode side across diaphragm 120, while hydrogen migrates to the cathode side. Heat exchanger 12 can obtain heat from the heated water remaining the electrolyzer or by the released, heated, oxygen.

[0047] In further embodiments, the secondary hydrogen production method is a sulfur-iodide system. In a sulfur-iodine system, sulfuric acid is heated under high temperatures of about 750-1000⁰C and low pressure under the reaction H₂SO₄ → H₂O + SO₂ + 1/2O₂. In certain embodiments, iodine can combine with the resultant sulfur dioxide and water under conditions known in the art under the reaction I₂ + SO₂ + 2H₂O ^→ 2HI + H₂SO₄. The 2HI reacts with water and sulfur dioxide to under temperatures of about 35O⁰C to produce hydrogen and sulfur dioxide under the reaction 2HI → H₂ + 1₂. The net result of the process is the same as electrolysis: 2H₂O → 2H₂ + O₂. None of the reactions occur with 100 percent efficiency, resulting in super-heated byproducts for heat exchanger 12 to remove heat from in order to heat organic solution in primary hydrogen production apparatus 96. Heat exchanger 14 can use heat from any heat source from this process, for example, the heated H₂SO₄, heated H₂O or oxygen. Regardless of where heat exchanger 12 acquires heat, the dual method enables two separate methods of hydrogen production, wherein the primary system uses heat energy from the secondary system in order to treat organic feed material for use in bioreactor 10.

[0048] In one embodiment, to maintain the temperatures at desired levels as known in the art, at least one temperature sensor 48 monitors a temperature indicative of the organic feed material temperature, preferably the temperature levels of equalization tank 14 and/or heat exchanger 12. In preferred embodiments, an electronic controller is provided having at least one microprocessor adapted to process signals from one or a plurality of devices providing organic feed material parameter information, wherein the electronic controller is operably related to the at least one actuatable terminal and is arranged to control the operation of and to controllably heat the heat exchanger and/or any contents therein. The electronic controller is located or coupled to heat exchanger 12 or equalization tank 14, or can alternatively be at a third or remote location. In alternate embodiments, the controller for controlling the temperature of heat exchanger 12 is not operably related to temperature sensor 48, and temperatures can be adjusted manually in response to temperature readings taken from temperature sensor 48. [0049] Organic feed material is then conveyed from heat exchanger 12 to bioreactor 10. Passage 18 connects heat exchanger 12 with bioreactor 10. Organic feed material is conveyed into the bioreactor through transport passage 18 at a desired flow rate. When pumps are operating and not shut down by, for example, low pH cut off device 52, the system is a continuous flow system with organic feed material in constant motion between containers such as reservoir 16, heat exchanger 12, bioreactor 10, equalization tank 14 if applicable, and so forth. Flow rates in the system can vary depending on retention time desired in any particular container. For example, in preferred embodiments, retention time in bioreactor 10 is between about 6 and 12 hours. To meet this retention time, the flow rate of passage 18 and effluent passage 36 are adjustable as known in the art so that organic feed material, on average, stays in bioreactor 10 for this period of time. In preferred embodiments, pump 26 also enable conveyance from heat exchanger 12 to bioreactor 10 through passage 18. In alternate embodiments, an additional conveying device can be specifically operably related to passage 18. [0050] The organic feed material is conveyed through passage 18 having a first and second end, wherein passage 18 provides entry access to the bioreactor at a first end of passage 18 and providing removal access to the heat exchanger at a second end of passage 18. Any type of passage known in the art can be used, such as a pipe or flexible tube. The transport passage may abut or extend within the bioreactor and/or the heat exchanger. Passage 18 can generally provide access to bioreactor 10 at any location along the bioreactor. However, in preferred embodiments, passage 18 provides access at an upper portion of bioreactor 10.

[0051] Bioreactor 10 provides an anaerobic environment conducive for hydrogen producing microorganisms to grow, metabolize organic feed material, and produce hydrogen. While the bioreactor is beneficial to the growth of hydrogen producing microorganisms and the corresponding metabolism of organic feed material by the hydrogen producing microorganisms, it is preferably restrictive to the proliferation of unwanted microorganisms such as methanogens, wherein methanogens are microorganisms that metabolize carbon dioxide and hydrogen to produce methane and water. Methanogens are obviously unwanted as they metabolize hydrogen. If methanogens were to exist in substantial quantities in bioreactor 10, hydrogen produced by the hydrogen producing microorganisms will subsequently be converted to methane, reducing the percentage of hydrogen in the produced gas. Sustained production of hydrogen containing gas is achieved in bioreactor 10 by a number of method steps, including but not limited to providing a supply of organic feed material as a substrate for hydrogen producing microorganisms, controlling the pH of the organic feed material, enabling biofilm growth of hydrogen producing microorganisms, and creating directional current in the bioreactor.

[0052] Bioreactor 10 can be any receptacle known in the art for holding an organic feed material. Bioreactor 10 is anaerobic and therefore substantially airtight. Bioreactor 10 itself may contain several openings. However, these openings are covered with substantially airtight coverings or connections, such as passage 18, thereby keeping the environment in bioreactor 10 substantially anaerobic. Generally, the receptacle will be a limiting factor in the amount of material that can be produced. The larger the receptacle, the more hydrogen producing microorganisms containing organic feed material, and, by extension, hydrogen, can be produced. Therefore, the size and shape of the bioreactor can vary widely within the sprit of the invention depending on throughput and output and location limitations.

[0053] A preferred embodiment of a bioreactor is shown in Figure 2. Bioreactor

80 can be formed of any material suitable for holding an organic feed material and that can further create an airtight, anaerobic environment. In the present invention, bioreactor 10 is constructed of high density polyethylene materials. Other materials, including but not limited to metals or plastics can similarly be used. A generally silo-shaped bioreactor 80 has about a 300 gallon capacity with a generally conical bottom 84. Stand 82 is adapted to hold cone bottom 84 and thereby hold bioreactor 80 in an upright position. The bioreactor 80 preferably includes one or a multiplicity of openings that provide a passage for supplying or removing contents from within the bioreactor. The openings may further contain coverings known in the art that cover and uncover the openings as desired. For example, bioreactor 80 preferably includes a central opening covered by lid 86. In alternate embodiments of the invention, the capacity of bioreactor 80 can be readily scaled upward or downward depending on needs or space limitations. [0054] Fresh organic feed material is frequently conveyed into bioreactor 10 to provide new substrate material for the hydrogen producing microorganisms in bioreactor 10. To account for the additional organic feed material and to maintain the solution volume level at a generally constant level, the bioreactor preferably provides a system to remove excess solution, as shown in Figures 1 and 3. In the present embodiment, the bioreactor includes effluent passage 36 having an open first and second end that provides a passage from inside bioreactor 10 to outside the bioreactor. The first end of effluent passage 36 may abut bioreactor 10 or extend into the interior of bioreactor 10. If effluent passage 36 extends into the interior of passage 10, the effluent passage preferably extends upwards to generally upper portion of bioreactor 10. When bioreactor 10 is filled with organic feed material, the open first end of the effluent passage allows an excess organic feed material to be received by effluent passage 36. Effluent passage 36 preferably extends from bioreactor 10 into a suitable location for effluent, such as a sewer or effluent container, wherein the excess organic feed material will be deposited through the open second end.

[0055] Bioreactor 10 preferably contains one or a multiplicity of substrates 90 for providing surface area for attachment and growth of microorganism biofilms. Sizes and shapes of the one or a multiplicity of substrates 90 can vary widely, including but not limited to flat surfaces, pipes, rods, beads, slats, tubes, slides, screens, honeycombs, spheres, object with latticework, or other objects with holes bored through the surface. Numerous substrates can be used, for example, hundreds, as needed. The more successful the biofϊlm growth on the substrates, the more fixed state hydrogen production will be achieved. The fixed nature of the hydrogen producing microorganisms provide the sustain production of hydrogen in the bioreactor.

[0056] Substrates 90 preferably are substantially free of interior spaces that potentially fill with gas. In the present embodiment, the bioreactor comprises about 100- 300 pieces of 1" plastic media to provide surface area for attachment of the microorganism biofilm. In one embodiment, substrates 90 are Flexiring™ Random Packing (Koch-Glitsch.) Some substrates 90 may be retained below the liquid surface by a retaining device, for example, a perforated acrylic plate. In this embodiment, substrates 90 have buoyancy, and float on the organic feed material. When a recirculation system is operably, the buoyant substrates stay at the same general horizontal level while the organic feed material circulates, whereby providing greater access to the organic feed material by hydrogen producing microorganism- and nonparaffinophilic microorganism- containing biofϊlm growing on the substrates.

[0057] In preferred embodiments, a directional flow is achieved in bioreactor 10.

Recirculation system 58 is provided in operable relation to bioreactor 10. Recirculation system 58 enables circulation of organic feed material contained within bioreactor 10 by removing organic feed material at one location in bioreactor 10 and reintroduces the removed organic feed material at a separate location in bioreactor 10, thereby creating a directional flow in the bioreactor. The directional flow aids the microorganisms within the organic feed material in finding organic sources and substrates on which to grown biofilms. As could be readily understood, removing organic feed material from a lower region of bioreactor 10 and reintroducing it at an upper region of bioreactor 10 would create a downward flow in bioreactor 10. Removing organic feed material from an upper region of bioreactor 10 and reintroducing it at a lower region would create an up-flow in bioreactor 10.

[0058] In preferred embodiments, as shown in Figure 1, recirculation system 58 is arranged to produce an up-flow of any solution contained in bioreactor 10. Passage 60 provides removal access at a higher point than passage 62 provides entry access. Pump 30 facilitates movement from bioreactor 10 into passage 60, from passage 60 into passage 62, and from passage 62 back into bioreactor 10, creating up-flow movement in bioreactor 10. Pump 30 can be any pump known in the art for pumping organic feed material. In preferred embodiments, pump 30 is an air driven centrifugal pump. Other arrangements can be used, however, while maintaining the spirit of the invention. For example, a pump could be operably related to a single passage that extends from one located of the bioreactor to another.

[0059] One or a multiplicity of additional treatment steps can be performed on the organic feed material, either in bioreactor 10 or elsewhere in the system, for the purpose of making the organic feed material more conducive to proliferation of hydrogen producing microorganisms. The one or a multiplicity of treatment steps include, but are not limited to, aerating the organic feed material, diluting the organic feed material with water or other dilutant, controlling the pH of the organic feed material, adjusting electrolyte contents (Na, K, Cl, Mg, Ca, etc.) and adding additional chemical compounds to the organic feed material. Additional chemical compounds added by treatment methods include anti-fungal agents, phosphorous supplements, yeast extract or hydrogen producing microorganism inoculation. The method performing these treatment steps can be any methods known in the art for incorporating these treatments. For example, in one embodiment, a dilution method is a tank having a passage providing controllable entry access of a dilutant, such as water, into bioreactor 10. In some preferred embodiments, the treatment steps are performed in recirculation system 58. In other embodiments, treatment steps of the same type may be located at various points in the bioreactor system to provide treatments at desired locations.

[0060] Certain hydrogen producing microorganisms proliferate in pH conditions that are not favorable to methanogens, for example, Kleibsiella oxytoca. Keeping organic feed material contained within bioreactor 10 within this favorable pH range is conducive to hydrogen production. In preferred embodiments, pH controller 34 monitors the pH level of contents contained within bioreactor 10. In preferred embodiments, the pH of the organic feed material in bioreactor 10 is maintained at about 3.5 to 6.0 pH, most preferably at about 4.5 to 5.5 pH, as shown in Table 2. In further preferred embodiments, pH controller 34 controllably monitors the pH level of the organic feed material and adjustably controls the pH of the solution if the solution falls out of or is in danger of falling out of the desired range. As shown in Figure 1, pH controller 34 monitors the pH level of contents contained in passage 62, such as organic feed material, with pH sensor 64. As could readily be understood, pH controller 34 can be operably related to any additional or alternative location that potentially holds organic feed material, for example, passage 60, passage 62 or bioreactor 10 as shown in Figure 3.

[0061] If the pH of the organic feed material falls out of a desired range, the pH is preferably adjusted back into the desired range. Precise control of a pH level is necessary to provide an environment that enables at least some hydrogen producing microorganisms to function while similarly providing an environment unfavorable to methanogens. This enables microorganism reactions to create hydrogen without subsequently being overrun by methanogens that convert the hydrogen to methane. Control of pH of the organic feed material in the bioreactor can be achieved by any means known in the art. In one embodiment, a pH controller 34 monitors the pH and can add a pH control solution from container 54 in an automated manner if the pH of the bioreactor solution moves out of a desired range. In a preferred embodiment, the pH monitor controls the bioreactor solution's pH through automated addition of a sodium or potassium hydroxide solution. One such apparatus for achieving this is an Etatron DLX pH monitoring device. Preferred ranges of pH for the bioreactor solution is between about 3.5 and 6.0, with a more preferred range between about 4.0 and 5.5 pH. [0062] The hydrogen producing reactions of hydrogen producing microorganisms metabolizing organic feed material in bioreactor 10 can further be monitored by oxidation-reduction potential (ORP) sensor 32. ORP sensor 32 monitors redox potential of organic feed material contained within bioreactor 10. Once ORP drops below about - 200 mV, gas production commences. Subsequently while operating in a continuous flow mode, the ORP was typically in the range of -300 to -450 mV. [0063] In one embodiment, the wastewater is a grape juice solution prepared using Welch's Concord Grape Juice ™ diluted in tap water at approximately 32 mL of juice per Liter. The solution uses chlorine-free tap water or is aerated previously for 24 hours to substantially remove chlorine. Due to the acidity of the juice, the pH of the organic feed material is typically around 4.0. The constitutional make-up of the grape juice solution is shown in Table 1.

Table 1. Composition of concord grape juice. Source: Welch's Company, personal comni., 2005.

Constituent Concentration (unit indicated)

Mean Range

Carbohydrates¹ 15-18 % glucose 6.2 % 5-8 % fructose 5.5 % 5-8 % sucrose 1.8 % 0.2-2.3 % maltose 1.9 % 0-2.2 % sorbitol 0.1 % 0-0.2 %

Organic Acids¹ 0.5-1.7 %

Tartaric acid 0.84 % 0.4-1.35 %

Malic acid 0.86 % 0.17-1.54 %

Citric acid 0.044 % 0.03-0.12 %

Minerals¹

Calcium 17-34 mg/L

Iron 0.4-0.8 mg/L

Magnesium 6.3-11.2 mg/L

Phosphorous 21-28 mg/L

Potassium 175-260 mg/L

Sodium 1-5 mg/L

Copper 0.10-0.15 mg/L

Manganese 0.04-0.12 mg/L

Vitamins¹

Vitamin C 4 mg/L

Thiamine 0.06 mg/L

Riboflavin 0.04 mg/L Niacin 0.2 mg/L

Vitamin A 80 LU. pH 3.0-3.5

Total solids 18.5% additional trace constituents in these categories may be present.

[0064] Bioreactor 10 further preferably includes an overflow cut-off switch 66 to turn off pump 26 if the solution exceeds or falls below a certain level in the bioreactor. [0065] The method further includes capturing hydrogen containing gas produced by the hydrogen producing microorganisms. Capture and cleaning methods can vary widely within the spirit of the invention. In the present embodiment, as shown in Figure 1, gas is removed from bioreactor 10 through passage 38, wherein passage 38 is any passage known in the art suitable for conveying a gaseous product. Pump 40 is operably related to passage 38 to aid the removal of gas from bioreactor 10 while maintaining a slight negative pressure in the bioreactor. In preferred embodiments, pump 40 is an air driven pump. The gas is conveyed to gas scrubber 42, where hydrogen is separated from carbon dioxide. Other apparatuses for separating hydrogen from carbon dioxide may likewise be used. The volume of collected gas can be measured by water displacement before and after scrubbing with concentrated NaOH. Samples of scrubbed and dried gas may be analyzed for hydrogen and methane by gas chromatography with a thermal conductivity detector (TCD) and/or with a flame ionization detector (FID). Both hydrogen and methane respond in the TCD, but the response to methane is improved in the FID (hydrogen is not detected by an FID, which uses hydrogen as a fuel for the flame).

[0066] Exhaust system 70 exhausts gas. Any exhaust system known in the art can be used. In a preferred embodiment, as shown in Figure 1, exhaust system includes exhaust passage 72, backflow preventing device 74, gas flow measurement and totalizer 76, and air blower 46.

[0067] The organic feed material may be further inoculated in an initial inoculation step with one or a multiplicity of hydrogen producing microorganisms, such as Clostridium sporogenes, Bacillus licheniformis and Kleibsiella oxytoca, while contained in bioreactor 10. These hydrogen producing microorganisms are obtained from a microorganism culture lab or like source. Alternatively, the hydrogen producing microorganisms that occur naturally in the waste solution can be used without inoculating the solution. In further alternative embodiments, additional inoculations can occur in bioreactor 10 or other locations of the apparatus, for example, heat exchanger 12, equalization tank 14 and reservoir 16.

[0068] In the present embodiment, the preferred hydrogen producing microorganisms is Kleibsiella oxytoca, a facultative enteric bacterium capable of hydrogen generation. Kleibsiella oxytoca produces a substantially 1:1 ratio of hydrogen to carbon dioxide through organic feed material metabolization, not including impurities. The 1:1 ratio often contains enough hydrogen such that additional cleaning of the produced gas is not necessary. The source of both the Kleibsiella oxytoca may be obtained from a source such yeast extract. In one embodiment, the continuous input of seed organisms from the yeast extract in the waste solution results in a culture of Kleibsiella oxytoca in the bioreactor solution. Alternatively, the bioreactor may be directly inoculated with Kleibsiella oxytoca. In one embodiment, the inoculum for the bioreactor is a 48 h culture in nutrient broth added to diluted grape juice and the bioreactor was operated in batch mode until gas production commenced.

Example 1

[0069] The apparatus combines a bioreactor with a grape juice facility. The organic feed material is a grape juice waste product diluted in tap water at approximately 32 mL of juice per liter. The solution is aerated previously for 24 hours to substantially remove chlorine. The dilution and aeration occur in a treatment container. The organic feed material is then conveyed into the feed container through a passage. [0070] The organic feed material is heated in the feed container to about 65°C for about 10 minutes to substantially deactivate methanogens. The organic feed material is heated with excess heat from the grape juice facility with a heat exchanger. The organic feed material is conveyed through a passage to the bioreactor wherein it is further inoculated with Kleibsiella oxytoca. The resultant biogases produced by the microorganisms metabolizing the organic feed material include hydrogen without any substantial methane.

Example 2

[0071] A multiplicity of reactors were initially operated at pH 4.0 and a flow rate of 2.5 mL min^"1, resulting in a hydraulic retention time (HRT) of about 13 h (0.55 d). This is equivalent to a dilution rate of 1.8 d^"1. After one week all six reactors were at pH 4.0, the ORP ranged from -300 to -450 mV, total gas production averaged 1.6 L d^"1 and hydrogen production averaged 0.8 L d^'1. The mean COD of the organic feed material during this period was 4,000 mg L^"1 and the mean effluent COD was 2,800 mg L^"1, for a reduction of 30%. After one week, the pHs of certain reactors were increased by one half unit per day until the six reactors were established at different pH levels ranging from 4.0 to 6.5. Over the next three weeks at the new pH settings, samples were collected and analyzed each weekday. It was found that the optimum for gas production in this embodiment was pH 5.0 at 1.48 L hydrogen d^'1 (Table 2). This was equivalent to about 0.75 volumetric units of hydrogen per unit of reactor volume per day.

Table 2. Production of hydrogen in 2-L anaerobic bioreactors as a function of pH.

Total H2 H2 per gas H2 L/g Sugar

PH L/day L/day COD moles/mole

4.0^a 1.61 0.82 0.23 1.81

4.5^b 2.58 1.34 0.23 1.81

5.0^c 2.74 1.48 0.26 2.05

5.5^d 1.66 0.92 0.24 1.89

6.0^d 2.23 1.43 0.19 1.50

6.5^e 0.52 0.31 0.04 0.32 ^a mean of 20 data points ^b mean of 14 data points ^c mean of 11 data points ^d mean of 7 data points ^e mean of 6 data points

[0072] Also shown in Table 2 is the hydrogen production rate per g of COD, which also peaked at pH 5.0 at a value of 0.26 L g^"1 COD consumed. To determine the molar production rate, it was assumed that each liter of hydrogen gas contained 0.041 moles, based on the ideal gas law and a temperature of 25° C. Since most of the nutrient value in the grape juice was simple sugars, predominantly glucose and fructose (Table 1 above), it was assumed that the decrease in COD was due to the metabolism of glucose. Based on the theoretical oxygen demand of glucose (1 mole glucose to 6 moles oxygen), one gram of COD is equivalent to 0.9375 g of glucose. Therefore, using those conversions, the molar H₂ production rate as a function of pH ranged from 0.32 to 2.05 moles of H₂ per mole of glucose consumed. As described above, the pathway appropriate to these organisms results in two moles of H₂ per mole of glucose, which was achieved at pH 5.0. The complete data set is provided in Tables 3a and 3b. [0073] Samples of biogas were analyzed several times per week from the beginning of the study, initially using a Perkin Elmer Autosystem GC with TCD, and then later with a Perkin Elmer Claras 500 GC with TCD in series with an FID. Methane was never detected with the TCD, but trace amounts were detected with the FID (as much as about 0.05 %).

[0074] Over a ten-day period, the waste solution was mixed with sludge obtained from a methane-producing anaerobic digester at a nearby wastewater treatment plant at a rate of 30 mL of sludge per 20 L of diluted grape juice. There was no observed increase in the concentration of methane during this period. Therefore, it was concluded that the preheating of the feed to 65° C as described previously was effective in deactivating the organisms contained in the sludge. Hydrogen gas production rate was not affected (data not shown).

[0075] Using this example, hydrogen gas is generated using a microbial culture over a sustained period of time. The optimal pH for this culture consuming simple sugars from a simulated fruit juice bottling wastewater was found to be 5.0. Under these conditions, using plastic packing material to retain microbial biomass, a hydraulic residence time of about 0.5 days resulted in the generation of about 0.75 volumetric units of hydrogen gas per unit volume of reactor per day.

[0076] Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims. Table 3a. Bioreactor Operating Data

GAS Liquid Readings CDO Performance

Total after collection volume scrubbing Effluent NaDH Net Feed Feed Effluent Remσvzi Loading Consumed Total gas i H2 H2

Date Reactor hours (πt) (πij (HlJ |πt) (πi-J ORP PH (πig/4 fag"-) fπgl) (93 M L/d-y l/dεy L/g COD

14-Mw A 5 540 220 780 0 780 -408 4.0 4,480 2.293 2,187 3.494 1.706 259 1.06 0.13

B 5 380 220 840 0 840 -413 4.1 4,480 2,453 2,027 3.763 1.702 1.82 1.06 0.13

14- Nbv C 5 350 170 870 0 870 -318 4.1 4,480 2.293 2,187 3.898 1.902 1.68 0.82 0.09

14-Mw D 5 320 130 920 0 920 -372 4.1 4,480 1.920 2,530 4.122 2355 1.54 0.62 0.06

14- KtV E 5 240 100 920 0 920 -324 4.3 4,480 2.773 1,707 4.122 1.570 1.15 0.43 0.06

14- Kbv F 5 50 25 810 0 810 -329 4.0 3,307 2,080 1,227 2.679 0.994 0.24 0.12 0.03

15Nbv A 5.5 450 230 ^■ 1120 25 1095 -400 4.0 3,307 3,787 (48Q) 3.621 -0.525 1.96 1.00 -0.44

15Mw B 5.5 450 235 1180 35 1145 -384 4.0 3,307 3.253 54 3.787 0.061 1.96 1.03 3.82

15NtW C 5.5 250 130 640 0 640 -278 4.0 3,307 3,520 (213. 2.116 -0.136 1.09 0.57 -0.95

15Nbv E 5.5 455 225 1160 0 1160 -435 4.0 3,307 3,407 (160) 3.836 -0.185 1.99 0.98 -121

15Mw F 5.5 430 235 1160 0 1160 -312 4.0 3,307 3,413 (10© 3.833 -0.123 1.88 1.03 -1.91

16-Ntw A 5 380 190 1020 27 993 -414 4.0 4,693 3,627 1,066 4.660 1.059 1.82 0.91 0.18

5-Dεc A 4.5 200 110 500 35 465 -439 4.0 4,267 4,160 107 1.984 0.050 1.07 0.53 2.21

18-Nbv A 5 360 190 200 0 200 -423 4.0 3,680 5,227 (1,547) 0.733 -0.309 1.73 0.91 -0.61

K)

21- MW A 4 320 170 800 40 7EO -429 4.0 3,493 3,680 (187) 2.655 -0.142 1.92 1.02 -1.20

22NbV A 375 285 190 725 21 704 -432 4.0 4,107 2293 1,813 2.891 1.277 1.82 1.22 0.15

29- Ntav A 4.25 310 155 750 24 723 -439 4.0 5,013 3,520 1,493 3.640 1.084 1.75 0.88 0.14

2-Dec A 3175 250 120 660 26 634 -438 4.0 4,587 3,893 694 2.908 0.440 1.60 0.77 0.27

6-Dec A 3 150 75 540 0 5« -441 4.0 4,853 3,093 1,760 2.621 0.950 1.20 0.60 0.08

17-Nbv A 5.5 300 160 1010 30 983 -414 4.0 4,907 3,520 1.387 4.809 1.359 1.31 0.70 0.12 averages 4.81 324 164 830 13 817 -392 4.0 4,092 3,213 879 3.344 0.718 1.61 0.82 0.23

16-Mw B 5 400 200 1125 45 1080 -397 4.5 4,693 3,520 1,173 5.053 1.267 1.92 0.93 0.16

16Mw D 5 400 165 960 60 am -360 4.5 4,693 3,573 1,120 4.224 1.008 1.92 0.73 0.16

1&Nbv E 5 490 240 1100 72 1028 -324 4.5 4,693 3,413 1,280 4.824 1.315 235 1.15 0.18

1-DEC B 3.5 500 260 57D 45 525 -415 4.5 5,173 3,680 1,493 2.716 0.784 343 1.78 0.33 δ-Dec B 3 470 240 650 40 610 -411 4.5 4,053 3,360 1,493 2.960 0.911 376 1.92 0.26

21-Nbv B 4 5BO 300 930 50 8Θ0 -397 4.5 3.493 3,147 346 3.074 0.305 336 1.80 0.98

2-Dec B 3.75 HO 320 830 SO 780 -407 4.5 4,587 3,413 1,174 ^• 3.578 0915 4.10 2.05 0.35

17-Nbv B 5.5 450 220 1165 50 1115 -406 4.5 4,907 2,933 1,974 5.471 2201 1.90 0.96 0.10

1&Nbv B 5 390 220 860 42 818 -406 4.5 3,680 2,960 720 3.010 0.589 1.87 1.06 0.37

22Nbv B 3.75 585 395 835 50 785 -397 4.5 4,107 2.720 1,387 3.224 1.089 3.74 2.53 0.36

29-Mw B 4.25 620 320 920 42 878 -410 4.5 5,013 3,307 1,707 4.402 1.433 350 1.81 0.21

5Dec B 4.5 390 190 753 37 713 -417 4.5 4,267 3,840 427 3.042 0.304 208 1.01 0.62

1&Nbv F 5 400 200 1082 93 389 -324 4.5 4,693 3.093 1,600 4.641 1.582 1.92 0.93 0.13

16Mw C 5 400 200 950 74 876 -325 4.B 4,693 2.933 1,760 4.111 1.541 1.92 0.93 0.13 a/erages 4.45 478 248 909 54 853 -385 4.5 4,539 3,278 1,261 3.883 1.079 258 1.34 0.23

Table 3b. Bioreactor Operating Data Continued.

GAS Reading. COD Perfαrrraπce

Tot alter collection volume scrubbing Effluent NECH Net Feed Feed Effluent Removal Loading Consumed Total gεs H2 HZ

Date Reactor hαuis (rrt) JmLJ (πtj (mLJ ORP pH (mgΛJ [mgΛJ (mgΛJ (9) (si LJdφ L/dsj Ug COD

17-Nw C 55 330 2C0 120 720 -344 49 4,907 2,880 2,027 3533 1 459 1 57 087 014

18- Nw C 5 3TO 200 1120 70 1050 -328 49 3,680 2,480 1,200 3884 1 260 1 78 096 016 29- Mw C 425 415 200 920 50 870 -403 49 5,013 3,093 1,920 4362 1 670 234 1 13 012 17-Nw E 55 490 270 1210 115 1095 -352 50 4,907 4,747 1B0 5.373 Q175 214 1 18 1 54

1-Dec D 3 5 540 250 710 85 525 -395 50 5,173 3,573 1,600 3233 1 000 370 1 71 025 17-Mw F 55 475 225 1120 130 930 -367 50 4,907 3,760 1,147 4853 1 135 207 093 020

5-Dec D 45 580 310 710 77 633 -423 50 4,267 3,573 694 2701 Q439 3.09 1 65 071

6-Dec D 3 450 240 490 43 447 -420 50 4,853 3,253 1,600 2169 0.715 360 1 92 034 17-Nw D 35 690 415 593 83 497 -326 50 4,907 4,213 694 2439 0.345 46B 285 120

2-Dec D 3.75 640 340 830 66 764 -412 50 4,587 3,787 800 3504 Q611 410 218 056 22Ntw C 3.75 460 235 800 50 750 -349 50 4,107 1.280 2,827 3.080 2120 294 1 89 OU averages 434 49B 268 848 81 767 -3745 50 4.664 3,331 1,333 a579 1 023 274 1 48 026 t 5-Dec C 4 5 470 250 900 103 797 -429 54 4,267 3,413 854 3401 0.680 251 1 33 037

LoU 1B-Nw F 5 90 45 BOO 55 545 -451 55 3,680 3,440 240 2006 Q131 Q43 022 034

21-Ntw D A 130 70 830 80 750 -454 55 3,493 3,360 133 2620 0.100 Q78 042 070

22Nw D 3.75 330 250 765 69 B9S -461 55 4,107 2,880 1,227 2853 0.854 230 1 60 029

29-Nw D 425 100 50 940 100 840 456 55 5,013 ?307 1,707 4211 1 434 056 028 003

2-Dec C 375 550 290 810 S3 717 -430 55 4,587 3,573 1,014 3289 0.727 352 1 86 040

6-Dec C 3 250 130 570 45 525 -428 55 4853 3,627 1.226 254Θ 0.644 200 1 04 020 a/erages 404 279 155 774 78 -4441 55 4,286 3,371 914 2982 Q633 1 66 092 024

21-Mw E 4 350 250 930 130 BOO -400 60 3,493 2,987 506 2794 0.405 210 1 50 062

22-Mw E 3.75 380 280 820 127 6S3 -411 60 4,107 2.453 1,653 2846 1 146 243 1 79 024

29- Mw E 425 330 230 870 71 799 -467 60 5,013 1,973 3,040 4005 2423 203 1 30 009

1-Dec E 3 5 420 230 77D 127 643 -471 60 5,173 2.933 2,240 3.326 1 440 28B 1 71 017

2-Dec E 375 230 170 540 85 455 -443 60 4,587 3,360 1.227 2087 Q558 1 79 1 09 030

5-Dec E 4 5 410 240 930 155 774 -487 60 4,267 3,253 1,014 3.303 Q785 219 1 28 031

6-Dec E 3 230 170 650 105 555 -490 60 4,853 2.293 2,5BO 2693 1 421 224 1 36 012

3/erages 382 354 227 789 114 674 -453 60 4,499 2750 1,749 3033 1 179 223 1 43 019

29- MiW 425 go 45 870 190 720 -501 65 5.013 1,707 3,307 3610 2381 0.61 025 002

2-Dec F 375 20 0 810 136 674 -497 65 4,587 3,573 1,014 3092 0.683 013 000 000

22-Mw F 375 120 105 790 128 662 -477 65 4,107 2,240 1,837 2719 1 233 Q77 067 008

5-Dec 4 5 10 0 670 — 121 549 -532 65 4.267 2.827 1,440 2343 0.791 005 003 000

6-Dec F 3 60 50 480 SO 390 -515 65 4,853 2,240 2,613 1 B93 1 019 048 0 40 005

21-Ntw 4 200 100 910 160 760 472 65 3,493 2,613 2655 0.669 1 20 060 015 a/erages 388 83 50 755 129 623 -499 65 4,387 2.533 1,853 2745 1 160 Q52 031 004

Selected Citations and Bibliography

Brosseau, J.D. and J.E. Zajic. 1982a. Continuous Microbial Production of Hydrogen Gas. Int. J. Hydrogen Energy 7(8): 623-628.

Brosseau, J.D. and J.E. Zajic. 1982ba. Hydrogen-gas Production with Citrobacter intermedins and Clostridium pasteurianum. J. Chem. Tech. Biotechnol. 32:496-502.

Cheresources Online Chemical Engineering Information, http://www.cheresources.com/heat_transfer_basics.shtml.

Iyer, P., M.A. Bruns, H. Zhang, S. Van Ginkel, and B.E. Logan. 2004. Hydrogen gas production in a continuous flow bioreactor using heat-treated soil inocula. Appl. Microbiol. Biotechnol. 89(1):119-127.

Kalia, V.C., et al. 1994. Fermentation of biowaste to H2 by Bacillus licheniformis. World Journal of Microbiol & Biotechnol. 10:224-227.

Kosaric, N. and R. P. Lyng. 1988. Chapter 5: Microbial Production of Hydrogen. In Biotechnology, Vol. 6B. editors Rehm & Reed, pp 101-137. Weinheim: Vett.

Logan, B.E., S.-E. Oh, LS. Kim, and S. Van Ginkel. 2002. Biological hydrogen production measured in batch anaerobic respirometers. Environ. Sci. Technol. 36(ll):2530-2535.

Logan, B.E. 2004. Biologically extracting energy from wastewater: biohydrogen production and microbial fuel cells. Environ. Sci. Technol., 38(9):160A-167A

Madigan, M.T., J. M. Martinko, and J. Parker. 1997. Brock Biology of Microorganisms. Eighth Edition. Prentice Hall, New Jersey.

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Prabha et al. 2003. H₂-Producing microorganism communities from a heat-treated soil Inoculum. Appl. Microbiol. Biotechnol. 66:166-173

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Claims

We Claim:

1. A method for dually producing hydrogen, comprising the steps of:

performing a secondary hydrogen production method wherein hydrogen is produced from one or a series of reactions under elevated temperatures to produce hydrogen and oxygen, the secondary hydrogen production method producing liquids or gases of elevated temperatures that provide heat,

heating organic feed material in a primary hydrogen production method with heat from the secondary hydrogen production method, wherein the organic feed material is conducive to the growth of hydrogen producing microorganisms,

conveying the organic feed material into a bioreactor of the primary hydrogen production method, wherein the bioreactor is an anaerobic environment, and

removing hydrogen from the bioreactor.

2. The method of claim 1, wherein the organic feed material is inoculated with hydrogen producing microorganisms.

3. The method of claim 2, wherein the organic feed material is inoculated within the bioreactor.

4. The method of claim 1, wherein heat is conveyed from the secondary hydrogen production system to the primary hydrogen production method with a heat exchanger.

5. The method of claim 1, wherein the liquids and gases of elevated temperatures are selected from the group consisting of water, steam, hydrochloric acid, oxygen and sulfur dioxide.

6. The method of claim 1, wherein the liquids and gases of elevated temperatures are at a temperature in a range of about 100 to 1000⁰C.

7. The method of claim 1, wherein the organic feed material is heated in one or a multiplicity of containers or passages prior to conveyance into the bioreactor.

8. The method of claim 1, wherein the organic feed material is heated by the heat to a temperature of about 60 to 100⁰C.

9. The method of claim 1, wherein the organic feed material in the bioreactor has a controlled pH.

10. The method of claim 9, wherein the organic feed material is controlled to a pH between about 3.5 and 6.0 pH.

11. The method of claim 1, wherein the secondary hydrogen production method is electrolysis.

12. The method of claim 1, wherein the secondary hydrogen production method is a sulfur-iodine system.

13. The method of claim 1, wherein the organic feed material is conveyed into the bioreactor with the aid of a pump.

14. The method of claim 1, wherein the temperature of the organic feed material is controlled with an electronic controller.

15. The method of claim 1 , wherein hydrogen is produced in the bioreactor by hydrogen producing microorganisms metabolizing the organic feed solution.

16. A method for dually producing hydrogen, comprising the steps of: performing a secondary hydrogen production method wherein hydrogen is produced from electrolysis of water into hydrogen and oxygen, the secondary hydrogen production method producing heated liquids or gases that provide heat,

heating organic feed material in a primary hydrogen production method with heat from the secondary hydrogen production method, wherein the organic feed material is conducive to the growth of hydrogen producing microorganisms,

conveying the organic feed material into a bioreactor of the primary hydrogen production method, wherein the bioreactor is an anaerobic environment, and

removing hydrogen from the bioreactor.

17. The method of claim 16, wherein the heat is conveyed from the secondary hydrogen production system to the primary hydrogen production method with a heat exchanger.

18 The method of claim 16, wherein the organic feed material in the bioreactor has a controlled pH.

19. The method of claim 18, wherein the organic feed material is controlled to a pH between about 3.5 and 6.0 pH.

20. The method of claim 16, wherein hydrogen is produced in the bioreactor by hydrogen producing microorganisms metabolizing the organic feed material.