US20060272955A1 - 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 substantially present to convert produced hydrogen to methane, a biogas that contains hydrogen without substantial methane can be produced.

Description

CROSS REFERENCE TO RELATED APPLICATION
• This application claims priority under 35 U.S.C. §1119(e) to U.S. Provisional Patent Application Ser. No. 60/685,963, filed May 31, 2005, entitled “SEQUENTIAL METHOD OF HYDROGEN PRODUCTION”
FIELD OF THE INVENTION
• 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
• 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.
• 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.
• 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 micro-organisms 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 methaniogens in a biological system has previously been largely inevitable, continuous production of hydrogen from hydrogen producing micro-organisms has been unsuccessful in the past.
• 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 Lying (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 ferinenters, whose most well known member isEscherichia 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)
• 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 CO₂generation 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.
• 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.
• 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.
• 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 2500° C., 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 1000° C. At higher temperature operating rates, lower levels of energy are required.
• 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.
• 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 (800-1000° C.) 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 21-11 reacts with water and sulfur dioxide to under temperatures of about 350° C. 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.
• 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
• 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.
• 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.
• 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.
• 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 100° C. kills or deactivates methanogens while leaving hydrogen producing microorganisms substantially intact.
• 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.
• 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.
• 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
• FIG. 1 is a plan view of a primary hydrogen production method proximate the secondary hydrogen production method.
• FIG. 2 is a side view of one embodiment of the bioreactor.
• FIG. 3 is a plan view the bioreactor.
• FIG. 4 is a plan view of a secondary hydrogen production method proximate the primary hydrogen production method.
• FIG. 5 is a plan view of a high temperature secondary hydrogen production method proximate the primary hydrogen production method.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• As used herein, the term “microorganisms” include microorganisms and substantially microscopic cellular organisms.
• 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.
• 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.
• 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.
• 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.
• 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.
• A dualhydrogen producing method100 in accordance with the present invention is shown inFIG. 1 wherein an apparatus using primary hydrogen production method96 is shown in detail. As shown inFIG. 1, primary hydrogen production method96 has a multiplicity ofcontainers including bioreactor10,heat exchanger12,optional equalization tank14 andreservoir16.Method100 further uses secondaryhydrogen production apparatus50 andpassage44 bridging primary hydrogen production method96 and secondary hydrogen production method98.Method100 produces gas inbioreactor10, 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.
• 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.
• 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)
• 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.
• 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 tobioreactor10 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 60-100° F. or, more preferably, 60-75°. These hydrogen producing microorganisms include, but are not limited to,Clostidium sporogenes, Bacillus licheniformisandKleibsiella 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 inbioreactor10 or elsewhere in the apparatus, for example,recirculation system58.
• In one embodiment of the invention, organic feed material is first contained inreservoir16.Reservoir16 is a container known in the art that can contain an organic feed material. The size, shape, and material ofreservoir16 can vary widely within the spirit of the invention. In one embodiment,reservoir16 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,reservoir16 is a wastewater well that is adaptable to receive and contain wastewater and/or effluent from an industrial facility. In further preferred embodiments,reservoir16 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.
• The organic feed material inreservoir16 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, fromreservoir16 tooptional equalization tank14 toheat exchanger12 tobioreactor10 to outside ofbioreactor10. In preferred embodiments, organic feed material contained inreservoir16 is conveyed intopassage22 withpump28.Pump28 is in operable relation toreservoir16 such that it aids removal movement oforganic feed material16 intopassage22 at a desired, adjustable flow rate, whereinpump28 can be any pump known in the art suitable for pumping liquids. In a preferred embodiment, pump28 is a submersible sump pump.
• The method may further include temporary deactivation of conveyance fromreservoir16 toequalization tank14 orheat exchanger12 if the pH levels of organic feed material inreservoir16 exceeds a predetermined level. In this embodiment,reservoir16 furthers include a lowpH cutoff device52, such that exiting movement intopassage22 of the organic feed material is ceased if the pH level of the organic feed material is outside of a desired range. ThepH cutoff device52 is a device known in the art operably related toreservoir16 andpump28. If the monitor detects a pH level of a solution inreservoir16 out of range, the device ceases operation ofpump28. The pH cut off level inreservoir16 is typically greater than the preferred pH ofbioreactor10. In preferred embodiments, the pH cutoff level is set between about 7 and 8 pH. The conveyance withpump28 may resume when the pH level naturally adjusts through the addition of new organic feed material intoreservoir16 or by adjusting the pH through artificial means, such as those ofpH controller34. In alternate embodiments, particularly whenreservoir16 is not adapted to receive effluent from an industrial facility, the pH cutoff device is not used.
• Passage22 provides further entry access intoequalization tank14 orheat exchanger12. Equalization tank is an optional intermediary container for holding organic feed material betweenreservoir16 andheat exchanger12.Equalization tank14 provides an intermediary container that can help control the flow rates of organic feed material intoheat exchanger12 by providing a slower flow rate intopassage20 than the flow rate of organic feed material into the equalization tank throughpassage22. An equalization tank is most useful whenreservoir16 received effluent from anindustrial facility50 such that it is difficult to control flow intoreservoir16. The equalization tank can be formed of any material suitable for holding and treating the organic feed material. In the present invention,equalization tank14 is constructed of high density polyethylene materials. Other materials include, but are not limited to, metals or acrylics. Additionally, the size and shape ofequalization tank14 can vary widely within the spirit of the invention depending on throughput and output and location limitations.
• The method preferably further includes discontinuance of conveyance from equalization tank intoheat exchanger12 if the level of organic feed material inequalization tank14 falls below a predetermined level. Low-level cut-offpoint device56 ceases operation ofpump26 if organic feed material contained inequalization tank14 falls below a predetermined level. This prevents air from being sucked bypump26 intopassage20, thereby maintaining an anaerobic environment inbioreactor10. Organic feed material can be removed throughpassage20 or throughpassage24.Passage20 provides removal access fromequalization tank14 and entry access intoheat exchanger12.Passage24 provides removal access fromequalization tank14 of solution back toreservoir16, thereby preventing excessive levels of organic feed material from fillingequalization tank14.Passage24 provides a removal system for excess organic feed material that exceeds the cut-off point ofequalization tank14. Bothpassage20 andpassage24 may further be operably related to pumps to facilitate movement of the organic feed material. In alternate embodiments,equalization tank14 is not used and organic feed material moves directly fromreservoir16 toheat exchanger12. This is a preferred embodiment when the method is not used in conjunction withindustrial facility50 such that effluent from the industrial facility is directly captured inreservoir16. Ifreservoir16 is one or a multiplicity of storage tanks holding an organic feed material,equalization tank14 may not be necessary. In these embodiments,passages connecting reservoir16 andheat exchanger12 are arranged accordingly.
• 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 ofheat exchangers12, wherein the organic feed material is heated within the heat exchanger by liquids or gasses of elevated temperatures from secondaryhydrogen production apparatus50 conveyed throughpassage44.Passage44 may further be associated with a pump device to control flow rates. After exitingheat exchanger12, gases or liquids originally conveyed throughpassage44 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.Passage20 provides entry access toheat exchanger12, whereinheat exchanger12 is any apparatus known in the art that can contain and heat contents held within it.Passage20 is preferably operably related to pump26.Pump26 aids the conveyance of solution fromequalization tank14 orreservoir16 intoheat exchanger12 throughpassage20, whereinpump26 is any pump known in the art suitable for this purpose. In preferred embodiments, pump26 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.
• A heating source formethod100 preferably isheat exchanger12 that uses heat or heat waste from secondary hydrogen production method98 to heat the organic feed material, wherein the heat exchanger is a heat exchanger known in the art. The heat waste may be transferred throughpassage44. 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 exchanger, which directs flow through baffles so that fluids to be ehated and cooled are separated by plates with very large surface area.
• To allow hydrogen producing microorganisms within thebioreactor10 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 inheat exchanger12. Methanogens are substantially killed or deactivated by elevated temperatures. Methanogens are generally deactivated when heated to temperatures of about 60-75° C. for a period of at least 15 minutes. Additionally, methanogens are generally damaged or killed when heated to temperatures above about 90° C. for a period of at least 15 minutes.Heat exchanger12 enables heating of the organic feed material to temperature of about 60-100° C. 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 ofheat exchangers12 can vary widely within the spirit of the invention depending on throughput and output required and location limitations. In preferred embodiments, retention time inheat exchanger12 is at least 20 minutes. Retention time marks the average time any particular part of organic feed material is retained inheat exchanger12.
• Heat is captured from secondary hydrogen production method98 and is used to partially or fully heat the organic feed material to the temperatures of about 60 to 100° C. 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 method96 of the invention as shown inFIG. 4.Electrolyzer114 includescell102 having acathode104 and ananode106, wherein applied electrical current112 is applied to the cell. The cell may further include amembrane108 as needed. Steam andhydrogen stream110 is conveyed intocell102, wherein the steam is heated at a temperature from about 100-1000° C. 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 throughion conducting membrane108 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 asheat exchanger12 or can be a separate condenser that functions in tandem withheat exchanger12. Either way, theheat exchanger12 obtains heat from the steam that exitscell102 and uses the heat to dually produce hydrogen in the primary hydrogen production method by elevate the temperature of organic feed material to about 60 to 100° C.
• Alternatively, secondary hydrogen production method is a high temperature electrolyzer that uses heated water, as inFIG. 5. Here, an electrical current is applied tocathode116 andanode118 under heated temperatures of about 100-1000° C. separating a portion of the heated water into oxygen and hydrogen. The oxygen migrates to the anode side acrossdiaphragm120, while hydrogen migrates to the cathode side.Heat exchanger12 can obtain heat from the heated water remaining the electrolyzer or by the released, heated oxygen.
• 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 750-1000° C. and low pressure under the reaction H₂SO₄→H₂O+SO₂+½O₂. 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 350° C. to produce hydrogen and sulfur dioxide under the reaction 2HI→H₂+I₂. 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 forheat exchanger12 to remove heat from in order to heat organic solution in primary hydrogen production apparatus96.Heat exchanger14 can use heat from any heat source from this process, for example, the heated H₂SO₄, heated H₂O or oxygen. Regardless of whereheat exchanger12 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 inbioreactor10.
• In one embodiment, to maintain the temperatures at desired levels as known in the art, at least onetemperature sensor48 monitors a temperature indicative of the organic feed material temperature, preferably the temperature levels ofequalization tank14 and/orheat exchanger12. 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 toheat exchanger12 orequalization tank14, or can alternatively be at a third or remote location. In alternate embodiments, the controller for controlling the temperature ofheat exchanger12 is not operably related totemperature sensor48, and temperatures can be adjusted manually in response to temperature readings taken fromtemperature sensor48.
• Organic feed material is then conveyed fromheat exchanger12 tobioreactor10.Passage18 connectsheat exchanger12 withbioreactor10. Organic feed material is conveyed into the bioreactor throughtransport passage18 at a desired flow rate. When pumps are operating and not shut down by, for example, low pH cut offdevice52, the system is a continuous flow system with organic feed material in constant motion between containers such asreservoir16,heat exchanger12,bioreactor10,equalization tank14 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 inbioreactor10 is between about 6 and 12 hours. To meet this retention time, the flow rate ofpassage18 andeffluent passage36 are adjustable as known in the art so that organic feed material, on average, stays inbioreactor10 for this period of time. In preferred embodiments, pump26 also enable conveyance fromheat exchanger12 tobioreactor10 throughpassage18. In alternate embodiments, an additional conveying device can be specifically operably related topassage18.
• The organic feed material is conveyed throughpassage18 having a first and second end, whereinpassage18 provides entry access to the bioreactor at a first end ofpassage18 and providing removal access to the heat exchanger at a second end ofpassage18. 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.Passage18 can generally provide access tobioreactor10 at any location along the bioreactor. However, in preferred embodiments,passage18 provides access at an upper portion ofbioreactor10.
• Bioreactor10 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 inbioreactor10, 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 inbioreactor10 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.
• Bioreactor10 can be any receptacle known in the art for holding an organic feed material.Bioreactor10 is anaerobic and therefore substantially airtight.Bioreactor10 itself may contain several openings. However, these openings are covered with substantially airtight coverings or connections, such aspassage18, thereby keeping the environment inbioreactor10 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.
• A preferred embodiment of a bioreactor is shown inFIG. 2.Bioreactor80 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,bioreactor10 is constructed of high density polyethylene materials. Other materials, including but not limited to metals or plastics can similarly be used. A generally silo-shapedbioreactor80 has about a 300 gallon capacity with a generally conical bottom84.Stand82 is adapted to hold cone bottom84 and thereby holdbioreactor80 in an upright position. Thebioreactor80 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,bioreactor80 preferably includes a central opening covered bylid86. In alternate embodiments of the invention, the capacity ofbioreactor80 can be readily scaled upward or downward depending on needs or space limitations.
• Fresh organic feed material is frequently conveyed intobioreactor10 to provide new substrate material for the hydrogen producing microorganisms inbioreactor10. 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 inFIGS. 1 and 3. In the present embodiment, the bioreactor includeseffluent passage36 having an open first and second end that provides a passage frominside bioreactor10 to outside the bioreactor. The first end ofeffluent passage36 mayabut bioreactor10 or extend into the interior ofbioreactor10. Ifeffluent passage36 extends into the interior ofpassage10, the effluent passage preferably extends upwards to generally upper portion ofbioreactor10. Whenbioreactor10 is filled with organic feed material, the open first end of the effluent passage allows an excess organic feed material to be received byeffluent passage36.Effluent passage36 preferably extends frombioreactor10 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.
• Bioreactor10 preferably contains one or a multiplicity ofsubstrates90 for providing surface area for attachment and growth of microorganism biofilms. Sizes and shapes of the one or a multiplicity ofsubstrates90 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 biofilm 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.
• Substrates90 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,substrates90 are Flexiring™ Random Packing (Koch-Glitsch.) Somesubstrates90 may be retained below the liquid surface by a retaining device, for example, a perforated acrylic plate. In this embodiment,substrates90 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 biofilm growing on the substrates.
• In preferred embodiments, a directional flow is achieved inbioreactor10.Recirculation system58 is provided in operable relation tobioreactor10.Recirculation system58 enables circulation of organic feed material contained withinbioreactor10 by removing organic feed material at one location inbioreactor10 and reintroduces the removed organic feed material at a separate location inbioreactor10, 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 ofbioreactor10 and reintroducing it at an upper region ofbioreactor10 would create a downward flow inbioreactor10. Removing organic feed material from an upper region ofbioreactor10 and reintroducing it at a lower region would create an up-flow inbioreactor10.
• In preferred embodiments, as shown inFIG. 1,recirculation system58 is arranged to produce an up-flow of any solution contained inbioreactor10.Passage60 provides removal access at a higher point thanpassage62 provides entry access.Pump30 facilitates movement frombioreactor10 intopassage60, frompassage60 intopassage62, and frompassage62 back intobioreactor10, creating up-flow movement inbioreactor10.Pump30 can be any pump known in the art for pumping organic feed material. In preferred embodiments, pump30 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.
• One or a multiplicity of additional treatment steps can be performed on the organic feed material, either inbioreactor10 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, intobioreactor10. In some preferred embodiments, the treatment steps are performed inrecirculation system58. 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.
• Certain hydrogen producing microorganisms proliferate in pH conditions that are not favorable to methanogens, for example,Kleibsiella ocyloca. Keeping organic feed material contained withinbioreactor10 within this favorable pH range is conducive to hydrogen production. In preferred embodiments,pH controller34 monitors the pH level of contents contained withinbioreactor10. In preferred embodiments, the pH of the organic feed material inbioreactor10 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 controller34 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 inFIG. 1,pH controller34 monitors the pH level of contents contained inpassage62, such as organic feed material, with pH sensor64. As could readily be understood,pH controller34 can be operably related to any additional or alternative location that potentially holds organic feed material, for example,passage60,passage62 orbioreactor10 as shown inFIG. 3.
• 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, apH controller34 monitors the pH and can add a pH control solution fromcontainer54 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.
• The hydrogen producing reactions of hydrogen producing microorganisms metabolizing organic feed material inbioreactor10 can further be monitored by oxidation-reduction potential (ORP)sensor32.ORP sensor32 monitors redox potential of organic feed material contained withinbioreactor10. 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.
• 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
  comm., 2005.

  Concentration (unit indicated)

  	Constituent	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	I.U.

  	pH		3.0-3.5
  	Total solids		18.5%
  	1additional trace constituents in these categories may be present.

• Bioreactor10 further preferably includes an overflow cut-off switch66 to turn offpump26 if the solution exceeds or falls below a certain level in the bioreactor.
• 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 inFIG. 1, gas is removed frombioreactor10 throughpassage38, whereinpassage38 is any passage known in the art suitable for conveying a gaseous product.Pump40 is operably related topassage38 to aid the removal of gas frombioreactor10 while maintaining a slight negative pressure in the bioreactor. In preferred embodiments, pump40 is an air driven pump. The gas is conveyed togas scrubber42, 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).
• Exhaust system70 exhausts gas. Any exhaust system known in the art can be used. In a preferred embodiment, as shown inFIG. 1, exhaust system includesexhaust passage72,backflow preventing device74, gas flow measurement andtotalizer76, andair blower46.
• The organic feed material may be further inoculated in an initial inoculation step with one or a multiplicity of hydrogen producing microorganisms, such asClostridium sporogenes, Bacillus licheniformisandKleibsiella oxytoca, while contained inbioreactor10. 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 inbioreactor10 or other locations of the apparatus, for example,heat exchanger12,equalization tank14 andreservoir16.
• In the present embodiment, the preferred hydrogen producing microorganisms isKleibsiella oxytoca, a facultative enteric bacterium capable of hydrogen generation.Kleibsiella oxytocaproduces 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 theKleibsiella oxytocamay 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 ofKleibsiella oxytocain the bioreactor solution. Alternatively, the bioreactor may be directly inoculated withKleibsiella oxyloca. 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
• 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.
• 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 withKleibsiella oxyloca. The resultant biogases produced by the microorganisms metabolizing the organic feed material include hydrogen without any substantial methane.
EXAMPLE 2
• 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⁻¹and hydrogen production averaged 0.8 L d⁻¹. The mean COD of the organic feed material during this period was 4,000 mg L⁻¹and 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

  4.0a	1.61	0.82	0.23	1.81
  4.5b	2.58	1.34	0.23	1.81
  5.0c	2.74	1.48	0.26	2.05
  5.5d	1.66	0.92	0.24	1.89
  6.0d	2.23	1.43	0.19	1.50
  6.5e	0.52	0.31	0.04	0.32
  amean of 20 data points
  bmean of 14 data points
  cmean of 11 data points
  dmean of 7 data points
  emean of 6 data points

• 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⁻¹COD 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 la 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 H₂production rate as a function of pH ranged from 0.32 to 2.05 moles of H₂per mole of glucose consumed. As described above, the pathway appropriate to these organisms results in two moles of H₂per mole of glucose, which was achieved at pH 5.0. The complete data set is provided in Tables 3a and 3b.
• 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 Clarus 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 %).
• 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 as not affected (data not shown).
• Using this example, hydrogen gas is generated using a microbial culture over a stained 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.
• 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

  Total

  after

  Liquid Readings

  		collection	volume	scrubbing	Effluent	NaOH	Net Feed
  Date	Reactor	hours	(mL)	(mL)	(mL)	(mL)	(mL)	ORP	pH
  14-Nov	A	5	540	220	780	0	780	−408	4.0
  14-Nov	B	5	380	220	840	0	840	−413	4.1
  14-Nov	C	5	350	170	870	0	870	−318	4.1
  14-Nov	D	5	320	130	920	0	920	−372	4.1
  14-Nov	E	5	240	100	920	0	920	−324	4.3
  14-Nov	F	5	50	25	810	0	810	−329	4.0
  15-Nov	A	5.5	450	230	1120	25	1095	−400	4.0
  15-Nov	B	5.5	450	235	1180	35	1145	−384	4.0
  15-Nov	C	5.5	250	130	640	0	640	−278	4.0
  15-Nov	E	5.5	455	225	1160	0	1160	−435	4.0
  15-Nov	F	5.5	430	235	1160	0	1160	−312	4.0
  16-Nov	A	5	380	190	1020	27	993	−414	4.0
  5-Dec	A	4.5	200	110	500	35	465	−439	4.0
  18-Nov	A	5	360	190	200	0	200	−423	4.0
  21-Nov	A	4	320	170	800	40	760	−429	4.0
  22-Nov	A	3.75	285	190	725	21	704	−432	4.0
  29-Nov	A	4.25	310	155	750	24	726	−439	4.0
  2-Dec	A	3.75	250	120	660	26	634	−438	4.0
  6-Dec	A	3	150	75	540	0	540	−441	4.0
  17-Nov	A	5.5	300	160	1010	30	980	−414	4.0
  averages		4.81	324	164	830	13	817	−392	4.0
  16-Nov	B	5	400	200	1125	45	1080	−397	4.5
  16-Nov	D	5	400	165	960	60	900	−360	4.5
  16-Nov	E	5	490	240	1100	72	1028	−324	4.5
  1-Dec	B	3.5	500	260	570	45	525	−415	4.5
  6-Dec	B	3	470	240	650	40	610	−411	4.5
  21-Nov	B	4	560	300	930	50	880	−397	4.5
  2-Dec	B	3.75	640	320	830	50	780	−407	4.5
  17-Nov	B	5.5	450	220	1165	50	1115	−406	4.5
  18-Nov	B	5	390	220	860	42	818	−406	4.5
  22-Nov	B	3.75	585	395	835	50	785	−397	4.5
  29-Nov	B	4.25	620	320	920	42	878	−410	4.5
  5-Dec	B	4.5	390	190	750	37	713	−417	4.5
  16-Nov	F	5	400	200	1082	93	989	−324	4.5
  16-Nov	C	5	400	200	950	74	876	−325	4.6
  averages		4.45	478	248	909	54	856	−385	4.5

  COD

  Performance

  		Feed	Effluent	Removal	Loading	Consumed	Total gas	H2	H2 L/g
  	Date	(mg/L)	(mg/L)	(mg/L)	(g)	(g)	L/day	L/day	COD
  	14-Nov	4,480	2,293	2,187	3.494	1.706	2.59	1.06	0.13
  	14-Nov	4,480	2,453	2,027	3.763	1.702	1.82	1.06	0.13
  	14-Nov	4,480	2,293	2,187	3.898	1.902	1.68	0.82	0.09
  	14-Nov	4,480	1,920	2,560	4.122	2.355	1.54	0.62	0.06
  	14-Nov	4,480	2,773	1,707	4.122	1.570	1.15	0.48	0.06
  	14-Nov	3,307	2,080	1,227	2.679	0.994	0.24	0.12	0.03
  	15-Nov	3,307	3,787	(480)	3.621	−0.525	1.96	1.00	−0.44
  	15-Nov	3,307	3,253	54	3.787	0.061	1.96	1.03	3.82
  	15-Nov	3,307	3,520	(213)	2.116	−0.136	1.09	0.57	−0.95
  	15-Nov	3,307	3,467	(160)	3.836	−0.185	1.99	0.96	−1.21
  	15-Nov	3,307	3,413	(106)	3.836	−0.123	1.88	1.03	−1.91
  	16-Nov	4,693	3,627	1,055	4.660	1.059	1.82	0.91	0.18
  	5-Dec	4,267	4,160	107	1.984	0.050	1.07	0.59	2.21
  	18-Nov	3,680	5,227	(1,547)	0.736	−0.309	1.73	0.91	−0.61
  	21-Nov	3,493	3,680	(187)	2.655	−0.142	1.92	1.02	−1.20
  	22-Nov	4,107	2,293	1,813	2.891	1.277	1.82	1.22	0.15
  	29-Nov	5,013	3,520	1,493	3.640	1.084	1.75	0.88	0.14
  	2-Dec	4,587	3,893	694	2.906	0.440	1.60	0.77	0.27
  	6-Dec	4,853	3,093	1,760	2.621	0.950	1.20	0.60	0.08
  	17-Nov	4,907	3,520	1,387	4.809	1.359	1.31	0.70	0.12
  	averages	4,092	3,213	879	3.344	0.718	1.61	0.82	0.23
  	16-Nov	4,693	3,520	1,173	5.068	1.267	1.92	0.96	0.16
  	16-Nov	4,693	3,573	1,120	4.224	1.008	1.92	0.79	0.16
  	16-Nov	4,693	3,413	1,280	4.824	1.315	2.35	1.15	0.18
  	1-Dec	5,173	3,680	1,493	2.716	0.784	3.43	1.78	0.33
  	6-Dec	4,853	3,360	1,493	2.960	0.911	3.76	1.92	0.26
  	21-Nov	3,493	3,147	346	3.074	0.305	3.36	1.80	0.98
  	2-Dec	4,587	3,413	1,174	3.578	0.915	4.10	2.05	0.35
  	17-Nov	4,907	2,933	1,974	5.471	2.201	1.96	0.96	0.10
  	18-Nov	3,680	2,960	720	3.010	0.589	1.87	1.06	0.37
  	22-Nov	4,107	2,720	1,387	3.224	1.089	3.74	2.53	0.36
  	29-Nov	5,013	3,307	1,707	4.402	1.496	3.50	1.81	0.21
  	5-Dec	4,267	3,840	427	3.042	0.304	2.08	1.01	0.62
  	16-Nov	4,693	3,093	1,600	4.641	1.582	1.92	0.96	0.13
  	16-Nov	4,693	2,933	1,760	4.111	1.541	1.92	0.96	0.13
  	averages	4,539	3,278	1,261	3.883	1.079	2.58	1.34	0.23

• TABLE 3b
  Bioreactor Operating Data Continued.

  GAS

  Tot

  after

  Liquid Readings

  		collection	volume	scrubbing	Effluent	NaOH	Net Feed
  Date	Reactor	hours	(mL)	(mL)	(mL)	(mL)	(mL)	ORP	pH
  17-Nov	C	5.5	360	200	840	120	720	−344	4.9
  18-Nov	C	5	370	200	1120	70	1050	−328	4.9
  29-Nov	C	4.25	415	200	920	50	870	−403	4.9
  17-Nov	E	5.5	490	270	1210	115	1095	−352	5.0
  1-Dec	D	3.5	540	250	710	85	625	−395	5.0
  17-Nov	F	5.5	475	225	1120	130	990	−367	5.0
  5-Dec	D	4.5	580	310	710	77	633	−423	5.0
  6-Dec	D	3	450	240	490	43	447	−420	5.0
  17-Nov	D	3.5	680	415	580	83	497	−326	5.0
  2-Dec	D	3.75	640	340	830	66	764	−412	5.0
  22-Nov	C	3.75	460	295	800	50	750	−349	5.0
  averages		4.34	496	268	848	81	767	−374.5	5.0
  5-Dec	C	4.5	470	250	900	103	797	−429	5.4
  18-Nov	F	5	90	45	600	55	545	−451	5.5
  21-Nov	D	4	130	70	830	80	750	−454	5.5
  22-Nov	D	3.75	360	250	766	68	696	−461	5.5
  29-Nov	D	4.25	100	50	940	100	840	−456	5.5
  2-Dec	C	3.75	550	290	810	93	717	−430	5.5
  6-Dec	C	3	250	130	570	45	525	−428	5.5
  averages		4.04	279	155	774	78	696	−444.1	5.5
  21-Nov	E	4	350	250	930	130	800	−400	6.0
  22-Nov	E	3.75	380	280	820	127	693	−411	6.0
  29-Nov	E	4.25	360	230	870	71	799	−467	6.0
  1-Dec	E	3.5	420	250	770	127	643	−471	6.0
  2-Dec	E	3.75	280	170	540	86	455	−443	6.0
  5-Dec	E	4.5	410	240	930	156	774	−487	6.0
  6-Dec	E	3	280	170	660	105	555	−490	6.0
  averages		3.82	354	227	789	114	674	−453	6.0
  29-Nov	F	4.25	90	45	870	150	720	−501	6.5
  2-Dec	F	3.75	20	0	810	136	674	−497	6.5
  22-Nov	F	3.75	120	106	790	128	662	−477	6.5
  5-Dec	F	4.5	10	0	670	121	549	−532	6.5
  6-Dec	F	3	60	50	480	90	390	−515	6.5
  21-Nov	F	4	200	100	910	150	760	−472	6.5
  averages		3.88	83	50	755	129	626	−499	6.5

  COD

  Performance

  		Feed	Effluent	Removal	Loading	Consumed	Total gas	H2	H2
  	Date	(mg/L)	(mg/L)	(mg/L)	(g)	(g)	L/day	L/day	L/g COD
  	17-Nov	4,907	2,880	2,027	3.533	1.459	1.57	0.87	0.14
  	18-Nov	3,680	2,480	1,200	3.864	1.260	1.78	0.96	0.16
  	29-Nov	5,013	3,093	1,920	4.362	1.670	2.34	1.13	0.12
  	17-Nov	4,907	4,747	160	5.373	0.175	2.14	1.18	1.54
  	1-Dec	5,173	3,573	1,600	3.233	1.000	3.70	1.71	0.25
  	17-Nov	4,907	3,760	1,147	4.858	1.135	2.07	0.98	0.20
  	5-Dec	4,267	3,573	694	2.701	0.439	3.09	1.65	0.71
  	6-Dec	4,853	3,253	1,600	2.169	0.715	3.60	1.92	0.34
  	17-Nov	4,907	4,213	694	2.439	0.345	4.66	2.85	1.20
  	2-Dec	4,587	3,787	800	3.504	0.611	4.10	2.18	0.56
  	22-Nov	4,107	1,280	2,827	3.080	2.120	2.94	1.89	0.14
  	averages	4,664	3,331	1,333	3.579	1.023	2.74	1.48	0.26
  	5-Dec	4,267	3,413	854	3.401	0.680	2.51	1.33	0.37
  	18-Nov	3,680	3,440	240	2.006	0.131	0.43	0.22	0.34
  	21-Nov	3,493	3,360	133	2.620	0.100	0.78	0.42	0.70
  	22-Nov	4,107	2,880	1,227	2.858	0.854	2.30	1.60	0.29
  	29-Nov	5,013	3,307	1,707	4.211	1.434	0.56	0.28	0.03
  	2-Dec	4,587	3,573	1,014	3.289	0.727	3.52	1.86	0.40
  	6-Dec	4,853	3,627	1,226	2.548	0.644	2.00	1.04	0.20
  	averages	4,286	3,371	914	2.982	0.636	1.66	0.92	0.24
  	21-Nov	3,493	2,987	506	2.794	0.406	2.10	1.50	0.62
  	22-Nov	4,107	2,453	1,653	2.846	1.146	2.43	1.79	0.24
  	29-Nov	5,013	1,973	3,040	4.006	2.429	2.03	1.30	0.09
  	1-Dec	5,173	2,933	2,240	3.326	1.440	2.88	1.71	0.17
  	2-Dec	4,587	3,360	1,227	2.087	0.558	1.79	1.09	0.30
  	5-Dec	4,267	3,253	1,014	3.303	0.785	2.19	1.28	0.31
  	6-Dec	4,853	2,293	2,560	2.693	1.421	2.24	1.36	0.12
  	averages	4,499	2,750	1,749	3.033	1.179	2.23	1.43	0.19
  	29-Nov	5,013	1,707	3,307	3.610	2.381	0.51	0.25	0.02
  	2-Dec	4,587	3,573	1,014	3.092	0.683	0.13	0.00	0.00
  	22-Nov	4,107	2,240	1,867	2.719	1.236	0.77	0.67	0.08
  	5-Dec	4,267	2,827	1,440	2.343	0.791	0.05	0.00	0.00
  	6-Dec	4,853	2,240	2,613	1.893	1.019	0.48	0.40	0.05
  	21-Nov	3,493	2,613	880	2.655	0.669	1.20	0.60	0.15
  	averages	4,387	2,533	1,863	2.745	1.160	0.52	0.31	0.04

Selected Citations and Bibliography
• Brosseau, J. D. and J. E. Zajic. 1982a. Continuous Microbial Production of Hydrogen Gas. lnt. J. Hydrogen Energy 7(8): 623-628.
• Brosseau. J. D. and J. E. Zajic. 1982ba. Hydrogen-gas Production withCitrobacter intermediusandClostridium 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 Rehin & Reed. pp 101-137. Weinheim: Vett.
• Logan, B. E., S.-E. Oh, I. S. Kimn and S. Van Ginkel. 2002. Biological hydrogen production measured in batch anaerobic respirometers. Environ. Sci. Technol. 36(11):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 Bioloy of Microorganisms, Eighth Edition, Prentice Hall, New Jersey.
• Nandi. R. and S. Sengupta. 1998. Microbial Production of Hydrogen: An Overview. Critical Reviews in Microbiology, 24(1):61-84.
• Noike et al. 2002. Inhibition of hydrogen fermentation of organic wastes by lactic acid microorganisms. International Journal of Hydrogen Energy. 27:1367-1372
• Oh, S.-E., S. Van Ginkel, and B. E. Logan. 2003. The relative effectiveness of pH control and heat treatment for enhancing biohydrogen gas production. Environ. Sci. Technol., 37(22):5186-5190.
• Prabha et al. 2003. H₂-Producing microorganism communities from a heat-treated soil Inoculum. Appl. Microbiol. Biotechnol. 66:166-173
• Wang et al. 2003. Hydrogen Production from Wastewater Sludge Using a Clostridium Strain. J. Env. Sci. Health. Vol. A38(9):1867-1875
• Yokoi et al. 2002. Microbial production of hydrogen from starch-manufacturing wastes. Biomass & Bioenergy; Vol. 22 (5):389-396.

Claims (20)

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 ofclaim 1, wherein the organic feed material is inoculated with hydrogen producing microorganisms.

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

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

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

6. The method ofclaim 1, wherein the liquids and gases of elevated temperatures are at a temperature in a range of about 100 to 1000° C.

7. The method ofclaim 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 ofclaim 1, wherein the organic feed material is heated by the heat to a temperature of about 60 to 100° C.

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

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

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

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

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

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

15. The method ofclaim 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 ofclaim 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 ofclaim 16, wherein the organic feed material in the bioreactor has a controlled pH.

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

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

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