Patent Application
20190078049
Expanding industrialization and increasing populations around the world continues to create an ever-increasing demand for energy, food, and potable water, while at the same time increasing the production of waste and potentially climate-altering greenhouse gases. It is well documented in the art that historical dependence on fossil fuels is becoming less reliable and/or more costly to manage its waste by-products. Similarly, conventional large-scale agriculture practices and the increasing presence of industrial waste run-off has reduced soil nutrient levels and negatively impacted natural and man-made water supplies, all of which reduce our ability to produce sustainable, nutritious food supplies for our communities.
Accordingly, the need and effort to identify and create means for generating alternative sources for renewable energy, as well as means for sequestering greenhouse gases, increasing soil viability, and remediating water supplies is well documented in the art.
According to described embodiments, an autonomous control system can be used with one or more of the systems or components described herein. For example, an autonomous control system can be used in combination with a biorefinery system described herein.
The foregoing aspects and many of the attendant advantages of this disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Embodiments of the present disclosure provide systems, components, and methods directed to generating energy and output products from biomass in a substantially closed loop system. The systems, components, and methods can be used alone or in combination as part of an integrated biorefinery system.
Referring to
An optional greenhouse 110 may be configured to contain one or more of the components in the system 100 and provide an environment to grow plant life. For example, in the illustrated embodiment, the greenhouse 110 is designed to contain the photosynthetic bioreactor system 104 and the anaerobic bioreactor system 106. Although shown as a complete system 100 in
Biorefinery systems of the present disclosure, for example, as seen in
Any industry producing waste heat or waste gas emissions may benefit from the biorefinery of the present disclosure. Non-limiting examples include industries using commercial boiler and/or incinerator systems, particularly those systems subject to governmental emission control such as the MACT and the CISWI rules in the United States. Other non-limiting examples include cement plants, coal plants, wood product manufacturers, data centers and server farms, and the like. Still other industries are those whose waste products include nitrogen-rich and phosphate-rich materials, such as waste water treatment plants; ranches; dairy, cattle and other animal farms, and the like. Still another industry is a defined community such as a college, hospital, prison, group living home, a research outpost, a community development and the like, including communities in both rural and urban settings.
The biomass pyrolysis system disclosed herein also can be utilized as a stand-alone mobile facility competent to pyrolyze biomass at a biomass source, such as a forest or landfill, providing its own fuel and electricity as desired.
Similarly, the autonomous control system disclosed herein can be utilized alone or together with one or more of the components described herein as stand-alone systems that serve to improve the efficiency and energy and waste management of an existing system.
Outputs from the system may include soil regenerating products, such as fertilizers and soil amendments. Therefore, in accordance with embodiments of the present disclosure, useful industries and applications include communities and industries desiring access to high-grade, nutrient-dense, organic soil regenerating products. Therefore, embodiments of the present disclosure also feature compositions, methods, and means for generating soil regenerating products useful for organic plant cultivation and other agricultural applications.
The biorefinery system described herein is competent to act as a biomimetic system, emulating the on-going, adaptive communication among biological systems in nature, particularly among species in an ecological community. In an ecological community, the member species continually adapt and modify behaviors over time in response to changes in the environment so as to maintain an overall balance of inputs and outputs within the community. In the biorefinery system, the photobioreactor, anaerobic bioreactor, pyrolysis device, and greenhouse space comprise components or “species” within the ecological community that is the biorefinery system. The biorefinery system includes an autonomous control system competent to (1) continually sense and communicate the current behavior of each component in the system and of the system in general, and (2) continually modify and adapt both component behavior and system behavior as needed for evolving changes in inputs and outputs of the system. The control system is competent to discover new methods and combinations for balancing inputs and outputs, learning from the behavior of system components, just as an ecological community does to evolve over time. The biorefinery structure described in detail below brings the members of a particular ecological community into close proximity, and the control system described in detail below accelerates the communication that naturally occurs within an ecological community. In addition to providing a system that generates product without unwanted waste, the system also accelerates the generation of natural products. In nature, it takes about 400 years for a tree to decompose and recarbonize soil, and about 1,000 years for natural processes to make one inch of soil. As described in detail below, the biorefinery system can produce natural, organic carbonized soil and soil products in 30-50 days.
Before describing the biorefinery system 100 of
As used herein, the term “biorefinery” or “bioprocessor” describes a facility that integrates one or more biomass conversion processes and equipment to produce fuels, power, heat, and other value-added chemicals or by-products from biomass.
As used herein, the term “biomass” describes biological material from living or recently living organisms and includes, without limitation, all matter produced by plants or other photosynthetic organisms, including plant matter; wood; wood waste; forest residues, including dead trees, branches and tree stumps; yard clippings; wood chips; food waste; algae or algae digestate; photosynthetic micro-organisms and their digestates. Biomass may also include lignocellulosic biomass.
As used herein, the term “lignocellulosic biomass” includes any plant biomass comprising cellulose, hemicellulose, and lignin including, without limitation, agricultural residues such as corn stover or other plant material residue left in a field after harvest; dedicated biomass energy crops; wood residues such as sawmill and paper mill discards, and forest detritus; and paper waste.
As used herein, the term “photosynthetic bioreactor” or “photobioreactor” or “PBR” describes a system for cultivating algae, including microalgae, and/or other photoautotrophs or photosynthesizing microorganisms for the purpose of fixing carbon dioxide, and/or producing a carbon-rich biomass. Useful organisms include, without limitation, diatoms and cyanobacteria (also known as blue-green algae), Chlorella, Spirulina, Botryococcus braunii, Dunaliella tertiolecta, Graciaria, Pleurochrysis carterae, and Sargassum, to name a few of the tens of thousands of species currently known to be in existence. In a preferable embodiment, the algae or other photosynthesizing microorganisms may be nitrogen fixing species.
It will be understood by those skilled in the art that useful photosynthesizing microorganisms, including microalgae, can include combinations of named or unnamed species growing in and collected from, local natural or man-made ponds. In one embodiment, useful photosynthetic microorganisms are cultured in the PBR in the presence of biomass, such as lignocellulosic biomass. In another embodiment, the microorganisms are cultured in the presence of spent brewing mash or hops solids, or similar germinated grain compositions. In another embodiment, the microorganisms are cultured in the presence of biochar or organic carbon. In another embodiment, the microorganisms are cultured in the presence of rocks or crystals (whether whole or pulverized as rock powder or rock salt) to provide micro-nutrients, such as minerals and trace elements.
As used herein, the term “anaerobic bioreactor” or “ABR” describes a biomass digestate process or system. Exemplary ABR biomass feedstock may include one or more of the following: the output of a PBR; food waste; ranch, dairy farm or other animal farm waste; and water treatment plant sludge and/or slurry. ABRs designed in accordance with embodiments of the present disclosure may include one or more stages for anaerobic digestion of biomass feedstock to produce both liquid and solid bioenergy products of value.
In one embodiment, the ABR biomass feedstock is algal feedstock, and the ABR output may include one or more of the following products: methane, hydrogen, carbon dioxide, a nitrogen-rich liquid digestate, referred to herein as a digestate liquor, comprising a high-grade organic nitrogenous soil regenerating product suitable for use an agricultural soil amendment or fertilizer; and nutrient-rich algal digestate solids. If the feedstock includes material that is not suitable for agriculture, for example, the sludge or slurry from a treatment plant, the digestate liquor and digestate solid can be used as non-agricultural soil amendments, such as to rebuild forest soils, as part of land repair and reclamation projects, including mining reclamation projects, or for use in municipal plantings or other horticultural applications. The ABR methane and hydrogen outputs may be used as feedstock for an energy conversion system, which can be used to convert the methane and/or hydrogen into energy in the form of electricity. The carbon dioxide can be used as a nutrient feedstock for the photosynthetic bioreactor system 104.
As used herein, the term “greenhouse” describes an environment or system that contains at least portions of the PBR and the ABR systems. The conditions in the greenhouse may be optimized so as to be used to grow discrete plant life, separate from the functions of both the PBR and ABR systems.
As used herein, the term “biomass gasifier” or “biomass pyrolysis system” describes a system for thermochemical decomposition of organic material or biomass at elevated temperatures in the absence of oxygen. The output is a porous, stable, carbon-rich product referred to herein as “biochar,” “organic carbon” (because it has been broken down to be substantially elemental carbon), “charcoal” and “active charcoal.” Biochar or organic carbon is a stable, porous solid rich in carbon content and minerals, and useful for sequestering and locking carbon into the soil, also referred to in the art as atmospheric carbon capture and storage.
As used herein, the term “organic carbon pyrolysis system” describes one embodiment of a biomass pyrolysis device or biomass gasifier of the present disclosure. The temperature of the pyrolysis in the organic carbon pyrolysis device may vary. For example, in one embodiment, biochar or organic carbon compositions are produced by pyrolysis at temperatures of at least 700° F. In another embodiment, organic carbon compositions are generated by pyrolysis at temperatures of less than 1,000° F. In another embodiment, organic carbon compositions useful in this disclosure are produced by pyrolysis at temperature ranges between 800-900° F.
As can be seen in
Provided below is a description of individual devices, the biorefinery system, and high value bioenergy outputs produced, as well as exemplary, non-limiting examples, which (1) demonstrate the suitability of the components and systems described herein in the methods of the disclosure, and (2) provide descriptions for how to make and use the same.
Referring to
The biorefinery system 100 described in
The individual components of the biorefinery system shown in
Referring to
Photosynthetic microorganisms convert sunlight and carbon dioxide into carbon-rich polymers, such as sugars, starches and oils, making them an ideal, natural carbon-sequestering agent. After a growth period, the carbon-rich polymers can subsequently be digested and modified to produce numerous high-value biofuels, including biodiesel and other useful fuels. As a non-limiting example, the microorganisms are one or more species of algae or microalgae. As another non-limiting example, the microorganisms may include other non-algal photosynthetic microorganisms, such as photosynthetic bacteria, for example, cyanobacteria (also known as blue-green algae). In one embodiment, the microorganisms used with the process described herein may include nitrogen-fixing species.
For simplification in the disclosure, photosynthetic microorganisms will be generally referred to herein as “algae,” even though suitable photosynthetic microorganisms may include bacteria that behave like algae. The utility of algae, as well as general descriptions for how to grow the algae and convert the product into biofuels, is well documented in the art. As mentioned above, the inventors have found that suitable photosynthetic microorganism species for an exemplary working system include diatoms and cyanobacteria, Chlorella, Spirulina, Botryococcus braunii, Dunaliella tertiolecta, Graciaria, Pleurochrysis carterae, and Sargassum, etc.
Different algal species have different growth requirements, and a given species may have different growth requirements depending on the time of day (or night) and/or the time of year; the quantity and quality of nutrients, minerals, and other components present in the growing environment, the water temperature, sunlight levels, and/or the density of the algal population. PBRs in accordance with embodiments of the present disclosure may provide means to manage and modulate growth conditions, provide continual or periodic feedstock inputs of algae, sun, carbon dioxide and/or other desired growth enhancing agents.
A PBR typically has means for modulating the water supply temperature because most algae have preferred growing temperatures. If the PBR gets too cold, the growth of the algae slows; if it gets too hot, the algae die. PBRs, and particularly the raceways in which the algae grow, can be heated by any means including using waste heat provided from one or more member devices in a biorefinery system (see, e.g.,
Alternatively, temperature modulation can be provided by thermally heated or cooled air or water. Such a system is known in the art as a heat-exchange or hydronics system. In a non-limiting example, well water or ground water can be collected and heated by the biorefinery system, for example, by utilizing the thermal output of the biomass pyrolysis element, for example, provided to the PBR by means of a hydronic radiant floor system. In another embodiment, the water utilized in the hydronic system includes condensed water vapor collected from the biomass pyrolysis system 102. In another non-limiting example, the fluid in a hydronics system may be a non-freezing liquid other than water. Such liquids are well-known and well-characterized in the heat-exchange/hydronics art. In one embodiment, such liquids comprise non-toxic antifreeze solutions such as glycols. In another non-limiting example, geothermally heated or cooled air is provided by means of earth tubes that utilize the earth's own geothermal energy to raise or lower the ambient temperature as desired. Exemplary earth tubes 550, as described in greater detail below, are shown in the illustrated embodiment of
Returning to
In the illustrated embodiment of
The raceway 202 may be sloped toward one end to facilitate drainage of the raceway 202 to a drain hole (not shown) during algal harvest. As described in greater detail below, the algal harvest may be drained into a concentrator tank 510 (see
Constant fluid flow in the raceway with minimized dead spots is desired to create a healthy algal growth environment. Referring to
Mixing in the PBR promotes a healthy algal growth environment, and can also be used to harvest the algae in the PBR. In the illustrated embodiments, mixing is achieved by the mixing devices, which may be paddle wheels or other suitable mixing devices. It should be appreciated that the mixing device may be configured and controlled to operate at different speeds, for example, steady state and harvest conditions. Moreover, if the control system senses frictional force on the mixing device, the control system may control the mixing device to speed up and/or reverse direction for a period to break up any material in the PBR that may be clogging the mixing device. In one embodiment of the present disclosure, mixing is at a steady state during the algal growth state; but during harvest, the mixing is increased to lift the algal sediments from the bottom of the raceway.
Referring to
The feedback for rate of flow of gases (such as carbon dioxide) and other nutrients to the raceway 202 via a gas bubbler 210 may be, for example, the pH of the water in the raceway 202 and, if the PBR is contained in the greenhouse 110 (see
Horizontal raceway PBRs designed in accordance with embodiments of the present disclosure may be large ponds that rely on solar energy and the ambient temperature of the environment to sustain the algal growth. In accordance with embodiments of the present disclosure, heat exchangers 212 can be used to regulate the temperature of the raceway 202 to enhance algal cultivation. As described in greater detail below, the heat exchangers 212 may be configured to harness heat outputs from other components and processes (for example, the biomass pyrolysis system 102) in the biorefinery system 100. The heat exchangers also can be configured to harness heat outputs from components outside of the biorefinery system, such as the excess heat produced by data center or server farm computers, for example. In one embodiment, the heat exchangers are part of a hydronic radiant heating/cooling system.
A control system may be used to continuously monitor and adjust multiple environmental parameters to maximize the algal rate of growth. For example, the heat exchangers 212 may be controlled to mimic the natural diurnal rhythms of the algae. Typically, growth rates increase when the temperature varies between 80° F. during the day and 65° F. at night. Because higher temperature reduces the solubility of gases in water, the growth cycle may be related to a natural breathing cycle of the algae.
Referring now to
In the illustrated embodiment, the raceways 402 are configured in a polygonal configuration, each having a side adjacent the valve system 530, as described in greater detail below.
One advantage of a multiple PBR system is that a fraction of the algae in the total system can be collected and concentrated over a period of time during the growing cycle. For example, if the growing cycle is about 8 days, the system can be designed such that one PBR may be drained each day to a collector tank to provide a batch-continuous system. Moreover, a multiple PBR system also allows for experimentation in the system because different algae can be grown in individual PBRs, and/or different operations conditions can be set in individual PBRs to experiment with and optimize the different growing conditions for the algae. It should be appreciated that the configuration of the raceways 402 in
The raceways 402 in the illustrated embodiment of
A selector valve system 530 is configured to select one of the raceway drains at any given time. Referring to
In the illustrated embodiment of
It should be appreciated that the valve system 530 may include a motor (not shown) to rotate the interior shaft 534 relative to the outer shaft 532. In one embodiment of the present disclosure, the individual raceway drains 522 are indexed using a Hall Effect device that senses when the hole 542 in the interior shaft 534 is aligned with the hole 540 in the raceway drain 522. Alternatively, the motor (not shown) may be a stepper motor that is programmed to travel a precise number of steps to index the hole 542 in the interior shaft 534 with the hole 540 in a subsequent raceway drain 522.
In another embodiment illustrated in
Referring to
When the algal discharge is received in the concentrator tank 520, there is no mixing and the harvest is left to decant. In that regard, the algal sludge separates and sinks to the bottom of the tank, while the water rises to the top of the tank, as indicated by respective lines 562 and 564 in the concentrator tank 520. In the illustrated embodiment, a pump 566 pumps the algal sludge to a holding tank 568 by line 570, and then to the anaerobic bioreactor system 106 (see
In the system configuration shown in
After decantation, the decanted water may be recycled and reused in the emptied raceway 402. In that regard, a decant pump 574 is positioned on a float 576 to float on the top of the decant water level. There, the pump 574 pumps water to a makeup water tank 578 through line 580, which refills at least one of the raceways 402 via the raceway selector valve 530. In addition to decanted water, an external water source may also add water to the makeup water tank 578 via line 580.
In the illustrated embodiment, the makeup water tank 578 is positioned about the raceway selector valve 530. Therefore, the force of gravity will deliver water from the tank 578 to the selected raceway 402 when the valve is open. In another embodiment of the present disclosure, the makeup water tank 578 may refill the raceways 402 with water via another line besides the raceway selector valve 530, for example, using a pump and a rotating water return pipe, as shown in the alternate embodiment in
As will be appreciated by those skilled in the art, separating water from algae can be both a time-consuming and an energy-consuming process. Using the selector valve embodiment illustrated in
In another embodiment, the selector valve embodiment illustrated in
In accordance with embodiments of the present disclosure, a control system can be used to control the functions of the PBR. For example, the control system may be used to:
1. Regulate the speed and direction of a mixing device (or paddle wheel) that circulates the algae in the raceway and mixes gases and nutrients into the raceway water. Prior to harvesting, the paddle wheel speed is increased to bring algae that have settled to the bottom of the raceway into suspension prior to opening the drain;
2. Regulate the flow and the mixture of carbon dioxide and nitrogen (air) through the bubblers;
3. Open and close the drain that carries the algae to the concentrator tank, and subsequently to the ABR for digestion;
4. Regulate the flow of hot water through the heat exchangers to control the raceway temperature; and/or
5. Regulate the algal growth rate by controlling raceway temperature, pH, bubbler gases, light access, raceway water speed, and the like.
The approach of the multi-raceway PBR system 102 shown in
Returning to
In warmer weather, the air in the earth tubes 550 is cooled geothermally, and the process is reversed. Cooled air terminates at the exchange zone, pushing warmer air up and increasing circulation and ambient air cooling. It will be appreciated by those skilled in the art that the interior earth tube termini may be at ground level, or may extend vertically some distance.
Thus, the ground under the greenhouse 110 acts as a thermal battery or thermal storage unit. In the case of the hydronic heat exchange system, the ground is a thermal battery for heat output generated by member devices in the systems described herein. This heat may be available to the PBRs and greenhouse itself, as desired.
As described above, additional agents can be added to the raceway colony to enhance algal growth. As non-limiting examples, suitable agents include is lignocellulosic biomass, pyrolized carbon (as described in greater detail below), waste mash from brewery production, germinated rice, other grain mash, mineral sources such as rock dust, etc. Placing the agent in a perforated container in a corner of the raceway, for example, is sufficient as the paddle activity will introduce the materials into the raceway over time. Preferred quantities of agent will vary depending on the algae species, raceway volume, and agent composition. As a non-limiting example, for a 70 sq. ft. raceway with water at a depth of 4 inches, the inventors found that the addition of 2-4 cups of agent has a positive impact on microalgal growth, particularly when the algae colony includes Chlorella and/or Spirulina species. Other useful agents include partially or completely digested algae. For example, algal mass can be collected from the hydrolysis tank, the collector tank and/or from the ABR output, and can be added to a raceway as desired.
When lignocellulosic biomass, such as wood chips, or organic carbon is used as an agent in the PBR, the material is preferably sized so that it becomes part of the dewatering system later on. In that regard, algae have a tendency to attach themselves to the cellulosic or carbon material. The advantage of such attachment is that the algae stays suspended in the raceway 402 and has less of a tendency to mat. Continued suspension helps the algae receive light, thereby improving its growth rate. As an alternative to the concentration tank 520, shown in
Lignin and hemicellulose in wood take a long time to digest anaerobically, but the high nitrogen content of algae can be used to break down the lignin and hemicellulose prior to digestion. Mixing cellulosic materials with algae increases the methane yield from the ABR, as discussed in greater detail below. The inventors found algae also attach well to pyrolized carbon, as compared to unpyrolized cellulosic materials. In addition, mixing pyrolized carbon as an additive in the PBR plays a role in aiding in digestion in the ABR. In that regard, cellulosic materials tend to slow down the digestion process of the algae because the cellulosic materials also need to be digested; however, pyrolized carbon generally does not require digestion because of its elemental form.
The operation of the PBR system 104, as seen in
After inoculation, the PBR raceway 402 is allowed to cultivate for a specified period of time. During this time, the mixing device 404 (see
When a pronounced decrease in the algal growth rate is detected, either by control or after a specific cultivation time period, the harvesting sequence is initiated and the biomass is moved to the next stage of processing. In one embodiment of the present disclosure, the raceways 402 are configured to be ready for harvest after about 24 hours. In another embodiment of the present disclosure, the raceways are configured to be ready for harvest in a range of about 1 to about 8 days, more preferably about 3 to about 8 days, and even more preferably about 5 to about 8 days.
As a non-limiting example, the PBR control system may be configured to sense the density of the algae. When the density reaches a certain point where the light penetration into the raceway is reduced, resulting in a slower rate of growth, the control system may open the drain at the bottom of the PBR and increase the speed of the mixing device to move the algae from the raceway 402 to the concentrator tank 520. As a non-limiting example, when harvesting, the mixing device may move at a rate of up to about 30 rpms.
After dewatering, most of the separated liquid is pumped back into the PBR to retain the heat and residual nutrients to begin the next batch of algae. The algal-cellulosic feedstock is pumped into the a holding tank 568 (see
As another non-limiting example, when a certain algal density is reached, the PBR control system may stop the mixing device 404, stop the flow of carbon dioxide and nitrogen in the bubblers, and increase the raceway temperature to above 85° F. Deprived of nutrients and exposed to excessive heat, the algae begin producing more lipids and then shortly thereafter they begin to die.
If left in this state for 1 or 2 days, the algal substrate begins to undergo hydrolysis in the raceway 402. In a system such as the one illustrated in
After 1 or 2 days, the control system turns the mixing device 404 back on and runs it at high speed to lift the settled algae and cellulose into suspension. The control system then opens the drain in the bottom of the PBR to move the algae into the collection tank 520 for dewatering. Most of the separated liquid is pumped back into the PBR to retain the heat and residual nutrients to begin the next batch of algae. After dewatering in the concentrator tank 520, the algal-cellulosic feedstock can be pumped directly into the acetogenic stage 632 (see
Returning to
In the illustrated embodiment of
After hydrolysis, the material from hydrolysis (i.e., sugars, fatty acids, and amino acids, indicated by blocks 608, 610, and 612) typically is subjected to an acidogenesis process to form carbonic acids and alcohols, hydrogen, carbon dioxide, and ammonia, indicated by blocks 614 and 616. Alternatively, hydrolysis and acidogenesis may occur concurrently, for example, in a single tank.
After acidogenesis, the material from acidogenesis (carbonic acids and alcohols, hydrogen, carbon dioxide, and ammonia, indicated by blocks 614 and 616) is subjected to acetogenesis to form hydrogen, acetic acid, and carbon dioxide, indicated by block 618. The hydrogen gas may be collected as an energy product for the energy conversion system. The carbon dioxide may be collected as feedstock for the PBR system.
After acetogenesis, the material from acetogenesis (algae digestate and acetic acid, indicated by blocks 618) is subjected to methanogenesis to form methane and carbon dioxide, indicated by block 620. Methane gas may be collected as an energy product for the energy conversion system. The carbon dioxide may be collected as feedstock for the PBR system.
Useful, benign, and environmentally safe microbial species for digestion are readily available. Specific microbial products may include a number of bacterial species that perform different steps in the digestion of the input feedstock.
Acetogenesis typically occurs through three groups of bacteria: homoacetogens; syntrophes; and sulphoreductors. Exemplary species include Clostridium aceticum; Acetobacter woodii; and Clostridium termoautotrophicum.
Exemplary methanogenic bacteria include Methanobacterium bryantii, Methanobacterium formicum, Methanobrevibacter arboriphilicus, Methanobrevibacter gottschalkii, Methanobrevibacter ruminantium, Methanobrevibacter smithii, Methanocalculus chunghsingensis, Methanococcoides burtonii, Methanococcus aeolicus, Methanococcus deltae, Methanococcus jannaschii, Methanococcus maripaludis, Methanococcus vannielii, Methanocorpusculum labreanum, Methanoculleus bourgensis (Methanogenium olentangyi & Methanogenium bourgense); Methanoculleus marisnigri, Methanofollis liminatans; Methanogenium cariaci, Methanogenium frigidum, Methanogenium organophilum, Methanogenium wolfei, Methanomicrobium mobile, Methanopyrus kandleri, Methanoregula boonei, Methanosaeta concilii, Methanosaeta thermophila, Methanosarcina acetivorans, Methanosarcina barkeri, Methanosarcina mazei, Methanosphaera stadtmanae, Methanospirillium hungatei, Methanothermobacter defluvii (Methanobacterium defluvii), Methanothermobacter thermautotrophicus (Methanobacterium thermoautotrophicum), Methanothermobacter thermoflexus, (Methanobacterium thermoflexum), Methanothermobacter wolfei (Methanobacterium wolfei), Methanothrix sochngenii.
ABRs described herein may be used in a biorefinery system, for example, the biorefinery system 100 shown in
In some applications, ABRs use smaller tanks with distributed processing and load balancing to reduce retention time and increase throughput. In that regard, the ABR system is scalable so more reactor stages can be easily added as energy and soil production demands grow or as the volume of the organic feedstock stream increases.
Referring to
Returning to
In the illustrated embodiment, ample water remains in the concentrated feedstock that exits the concentrator tank 520, so that it can be pumped from the concentrator tank 520 to the holding tank 568.
After the feedstock has been pumped to the collection tank 568, the flow of biomass through the ABR system 104 is primarily driven by gravity. Because the methanogenic stage takes about twice as long as the acetogenic stage, two methanogenic tanks 634 and 636 are used in parallel (per one acetogenic tank 632) to keep the process running continuously. Sensors for pH in the acetogenic tank 632 indicate the timing for moving the contents from the acetogenic tank to one of the lower methanogenic tanks 634 or 636. The methanogenic tank 634 or 636 that is being loaded from above also releases its contents (containing the liquid and solid fertilizers) via line 644 into a collection area below the ABR (not shown).
Temperature control is important in an ABR system 106 for the rapid digestion of the algal or another microorganism mixed with cellulose in a feedstock blend that comes from the PBRs. The feedstock is at least at ambient temperature, and preferably, warm as it moves from the PBR to the ABR. Ambient to warm temperature is preferred because the acetogenic bacteria tend to work best at about 70° F. There is some heat loss in the dewatering process but the feedstock arrives in the collection tank warm enough to be brought quickly up to temperature. Heat rising from the first stage tank brings the feedstock to the optimal temperature. Each tank uses a separate computer controlled heat exchanger to maintain and vary the temperatures as needed.
Referring to
Multiple valves 560, 562, 564, 566, and 568 are employed to control the path of the liquid feedstock through the ABR system 106. The valves are preferably computer controlled by an intelligent control system. In addition, a methane off-gas can be purged and collected from the methanogenic stage tanks 634 and 636. Valves 570 and 572 control the flow of the off-gas to a manometer or gas compression tank 674 via line 676, which is then configured to supply methane gas via line 678 to other components in the biorefinery system 100. Carbon dioxide may also be an off-gas. As shown in the illustrated embodiment, heat exchangers 680 and 682 may be employed to control the temperatures of the various tanks 632, 634, and 636.
The preferred retention times for each tank in the ABR is as follows:
Therefore, the total retention time in the ABR, from hydrolysis tank through methanogenesis tank, for a single batch is about 18-40 days, and preferably about 20 days. Retention time through the acetogenic and methanogenic stages (without hydrolysis) is about 13-35 days, preferably about 15 days. In accordance with one method, the acetogenic stage tank has a retention time of about 5 days, and the retention times of each of the methanogenesis stage tanks may be staggered by about 5 days, such that as one tank is at peak methane production the other is ramping up production. When the production rate of one of the methanogenic stage tanks begins to fall off the acetogenic stage tank is ready to replenish the methanogenic stage tank.
Although shown as a separate hydrolysis step, it should be appreciated that the hydrolysis step may begin in the PBR before the harvesting and dewatering functions or may take place in a separate hydrolysis tank, as described in greater detail above. Combining and overlapping the PBR and ABR functions provides a unique and useful improvement over known systems, and highlights the value of an integrated, intelligent cooperative biorefinery system.
A control system may be implemented to regulate the function of the ABRs. For example, temperature, pH, input, and output data may be regulated by the digital control system (DCS) to accelerate the digestion of algal-cellulosic feedstock. The control system is configured to open and close appropriate valves to move the digestate through the system at the appropriate times. The control system may also control and monitor the flow of methane gas from the methanogenic stage in the ABR into a manometer or gas compression tank for storage. The methane collected may be held and compressed for delivery, for example, to the fuel cells (or micro turbines) that may convert it into electrical power. The control system may similarly control and monitor the flow of hydrogen from the acetogenic stage.
In at least one embodiment, recirculation pump (macerator pump) circuitry includes control circuitry for the pump. Three daughter boards collect the data and control the valves and pumps on the each of the ABR tanks. In this example, there is one main control board per tank. A small pump control board can be installed on the base of the pump in an appropriate plastic box. A control line sends the signal to turn the pump on and off. The pump control board uses 24 VDC power. In one embodiment, each of the three ABR tanks have a recirculation pump with a control board attached on or near the pump. The circuitry can be implemented as production quality printed circuits. ABR control software facilitates wireless connection to other control components.
In at least one embodiment, core circuitry performs several functions, including functions relating to harvesting of algae as well moving water between the algal raceways. In this example, an Arduino board includes logic for performing functions such as regulating pumps and valves automatically and maintaining temperatures. For example, if one of the pumps starts drawing too much amperage because it gets clogged, the core circuitry can send a message to the pump to shut down while it tries to unclog itself by running fluid backwards through the line.
In at least one embodiment, gas valve controller circuitry includes “valve close” and “valve open” components.
In one embodiment of the present disclosure, the biorefinery system is a greenhouse system. Returning to
In addition, the high-grade nitrogen fertilizer and nutrient-dense soil regenerating materials produced in this biorefinery provide an ideal growing substrate to produce high-quality, healthy plants. Moreover, plant life irrigation water may be received from reclaimed water in the biomass pyrolysis system 102, described in detail below.
As an example, a biorefinery such as is illustrated in
Referring to
The methane and, if desired, hydrogen can be converted to electrical power, and all or a large fraction of the digestate can be used to produce high value organic soil regenerating products and/or amendments, alone or blended with other waste material at the mill site. In particular, the products can comprise Digestate Liquor, Algal Digestate Solid, organic carbon, or any combination thereof. The combined energy output for a single GPH, producing 2 net tons of organic carbon and 500 gallons of digestate every 5 days is about 250 kWatts produced continuously (about 0.9 MBTU/hr).
Megawatts of continuous power can be obtained by increasing the amount of organic carbon generated daily. The balance of inputs and outputs can be maintained by providing the additional pyrolysis outputs as feedstock for other processes. For example, additional organic carbon can be used in a biofilter reactor, and additional carbon dioxide can be provided to landfills or composting piles to accelerate digestion. Alternatively, a system of multiple biorefineries can be built together to accommodate the additional pyrolysis outputs. The polygonal architecture of the biorefinery makes it easy to create a modular grouping of, for example, six units.
The greenhouse system 110 may use low temperature (<120° F.) thermal and geothermal systems to drive the process. In that regard, heat exchangers and hydronic systems comprising geothermal well water and/or reclaimed process water may be used to keep the algae in the PBRs warm and to keep the anaerobic digestion in the ABRs at the optimal temperatures.
Referring to
Referring to
As can be seen in
When received, the biomass feedstock moves from a feedstock hopper 710 to the pyrolysis chamber 720, for example, using a rotating auger 726. In the pyrolysis chamber 720 biomass is heated to drive off the hydrocarbons, sometimes referred to in the art as “syngas.” Syngas is a gas mixture that includes an intermediate form in the process of making synthetic natural gas (therefore, its nickname “syngas”). Sample syngas components typically include methane, CO (carbon monoxide), carbon dioxide, hydrogen, and sometimes, nitrogen and NOx gases (which may be nominal), and can include trace elements of impurities like sulfur.
The pyrolysis chamber 720 may be divided into two zones, a preheat zone 730 and a char zone 732. The preheat zone 730 may be maintained in a temperature range of about 180F to about 700F, and preferably in the range of about 200F to about 600F. The temperature in the preheat zone 730 may be maintained by a heating device 734 in the char zone 732, as described in greater detail below, or by a separate heating device (not shown).
The primary purpose of the preheat zone 730 is to heat off any water that may be trapped in the feedstock biomass, which boils off at 212F. The water and other vaporized components are collected at an outlet 736 and travels through line 738 to a system 740 for condensing, scrubbing, and compressing the water and other exhaust from the pyrolysis chamber 720 (for example, but not limited to, syngas, bio-oils, and alcohols, as described below). The water may be reclaimed and used in other systems in a biorefinery system 100, for example, as water in the raceways 402 of the PBR system 104 or as irrigation water for plant life in the greenhouse system 110.
Therefore, the feedstock is dried in the preheat zone 730 in preparation for entry into the char zone 732. In the char zone 732, the preheated biomass feedstock is heated to a temperature in the range of about 600F to about 1200 F, and more preferably about 700F to about 850F. In a non-limiting example, the char zone 732 is configured to heat to about 800F for about 15 to about 20 minutes. Heating may be achieved by a heating device 734, shown as a series of burners, positioned in the char zone 732. The feed gases to the heating device 734 may include methane or hydrogen, for example, from other components in the biorefinery system 100, bio-oils and alcohols collected from the pyrolysis chamber 720, or other combustible gas sources. Exhaust from the heating device 734 is collected in the outer exhaust chamber 722 surrounding the inner pyrolysis chamber 720. The exhaust may include carbon dioxide and other exhaust gases, and flow may be delivered directed to the PBR system 104 as a feedstock for the algal colony.
In the char zone 732, the biomass is converted to biochar or organic carbon. Syngas is collected at an outlet 742 and travels through line 744 to the condenser, scrubber, and compressor system 740. There, bio-oils, alcohols, and water may be condensed, scrubbed, and separated. Any components that may be used to fuel the system heating device 734 may be sent via line 746 to be combined with input methane at line 748 and methane support valve 752 as feed gases to the heating device 734 via line 750. Air intake may also be directed to the heating device 734 via line 752 and air intake valve 754 to combine with line 750. In the alternative, excess gases that are not sent to the heating device 734 may be diverted via flow control valve 756 to a generator or boiler or another system in the biorefinery system 100 via line 754.
After the auger 726 moves the biomass through the preheat and char zones 730 and 732 in the pyrolysis chamber 720, the auger 726 moves the organic carbon to a cool down zone 760, in which one or more heat exchangers 762 collect heat from the biomass. The heat collected by the heat exchangers 762 may be directed to the ABR system 106 (see
Depending on the size of the pyrolysis system 102, enough heat can be collected to power both a biorefinery system 100 and a lumber mill, for example, including operating the mill's kiln. Processing 6-30 tons of biomass daily is well within the scope of the system described herein. The system 100 is carbon negative and could also qualify an industrial site utilizing the refinery for further tax rebates and carbon offset trading incentives when carbon legislation passes.
The operation of the biomass pyrolysis system 102 will now be described in greater detail. Initially the system 102 may use either propane or methane delivered to the heating device 734 to start the process. As a non-limiting example, the methane may be an output product from the ABR system 106. Alternatively, an external source such as propane may be used.
When the biomass pyrolysis system 102 produces a sufficient volume of syngas to support the pyrolytic process, the system may be powered by syngas or by a combination of gases. The exhaust gas from the combustion of gases may be vented, cooled, and pumped through the PBR gas bubbler system as feedstock for the algae.
With the heating device 734 on, the char zone 732 comes up to temperature and heats the exhaust chamber 722 surrounding the pyrolysis chamber 720. This in turn heats the preheat zone 730 bringing the biomass feedstock up to temperature, driving off moisture in the form of water vapor as described above. The vapor from the preheat zone 730 may be collected, condensed and distributed to other components in the overall biorefinery system 100, for example, as water feedstock to the PBR system 104.
Excess heat from the pyrolysis chamber 720 may be collected and distributed to other components in the overall biorefinery system 100, as needed, for example, to the PBR and/or ABR systems 104 or 106. Syngas production requires the high temperatures achieved in the char zone 732. The syngas output may be collected and then fractionated, e.g., by means of fractional distillation, and distributed, for example, to the heating device 734 for further powering the pyrolysis system 102. Also, a bubbler or scrubber can be used to separate methane, which does not dissolve in water, from CO2, which does. The carbon-enriched water then can be transmitted to the PBR system 104 for use as a nutrient input. Excess carbon dioxide not used by the PBR system 104 could be used in alternative way, for example, shunted to feed a compost pile or a landfill waste pile.
As the organic carbon output moves out of the char zone 732, the organic carbon enters a section of the pyrolysis system 102 comprising a heat exchanger 762, such as a water jacket. The heat exchanger process (1) cools the organic carbon such that it reaches ambient temperatures by the time it moves to the output hopper, and (2) collects the excess heat that then can be provided as needed to other member devices, such as the ABR and/or PBR systems 104 and/or 106.
The biomass pyrolysis system of this disclosure contemplates using the hot gas to generate electricity by means of a thermoelectric generator means and the heat exchange system described hereinabove. Hot gas from the burner is injected into the center of the biomass pyrolysis system's char zone auger, as shown in
In still another embodiment, illustrated in
Preferred organic carbon compositions are generated at temperatures in the range of at least 700-1000° F., more preferably in the range of 800-900° F. The time it takes to move feedstock through a biomass pyrolysis system 102 will be dependent on a range of variables, including the moisture content of the feedstock, the feedstock species, and the time necessary to remove all syngas, for example, all of which will impact the auger rotation speed. These variables may be managed and controlled by a suitable control system.
In addition, preferred ratios of pyrolysis chamber 720 length to diameter may produce optimal output production. In one embodiment, the preferred length to diameter ratio is 12:1, where pyrolysis chamber 720 length is measured from the start of the preheat zone 730 to the end of the char zone 732 in
A control system may be used in the biomass pyrolysis system 102 to sense and regulate the flow of thermal energy and carbon dioxide through the entire system for the optimal production of biofuels and electricity. Excess heat can be used locally for other industrial processes or diverted into a geothermal storage system for later use, for example, by earth tubes 550 or other geothermal heat exchangers.
In an ABR-biomass pyrolysis-generator loop, heat can be used to generate electricity, which can in turn be used to power the biomass pyrolysis system itself and, potentially, other devices or systems. Temperature differentials (e.g., gas temperature differentials, liquid temperature differentials) within the system can be used to generate electricity. For example, using a thermoelectric generator (TEG), cool return water or hydronics fluid from the PBR and/or ABR heat exchange system, and hot gas output from the pyrolysis system, the necessary temperature differential can be achieved across a TEG to generate electricity. In this way, heat that might ordinarily be lost as waste heat can be used to generate electricity. By incorporating this thermoelectric technology into a biomass pyrolysis device disclosed herein, kilowatts of power can be generated while using the heat for the ABR and raceways, and also allowing the production of syngas to generate more power. The biomass pyrolysis system could generate enough electrical power from the heat to power itself, augers, valves, fans, and the like, and potentially a conveyance system that feeds it.
In an example embodiment, a biomass pyrolysis system of this disclosure comprises a section called a charring core. The cutaway diagram shown in
Though there are many different types of wood gasifiers in the world today, in an example embodiment, the biomass pyrolysis system is designed to be an integral part of a closed loop system in which waste byproducts are looped back into the system and used in the production of organic fertilizer and electricity. Waste heat generated by the pyrolysis system disclosed herein is captured and used to regulate the temperatures in photobioreactors and anaerobic bioreactors and/or to generate electricity by means of a TEG. The carbon dioxide effluent is circulated through the PBR as feedstock to grow algae.
Organic carbon produced by the biomass pyrolysis system 102 can be blended with the high-nitrogen amendments generated by the ABR system to boost its agricultural and/or soil regenerating value. In addition, the organic carbon output can be used as a substrate for sequestering contaminants, pollutants, and impurities from water supplies, as from a water treatment plant, or waste water from an industrial site, thereby remediating the water and providing a ready collection device for unwanted impurities.
Lumber mills typically use their trash or remainder wood, known as “hog fuel” (e.g., pulverized bark, shavings, sawdust, low-grade lumber, and lumber rejects) to fuel the kilns that dry their lumber. A medium-size mill that utilizes a standard boiler system for heating its kilns will consume approximately 50 tons of hog fuel a day to fuel its boiler system. Depending on the efficiency of its boiler system, it can use between 8,000-25,000 pounds of steam/hour to keeps its kilns at a temperature of 180° F. for a day. A biomass pyrolysis system 102, as described herein and designed to process about 6 tons of waste woody biomass a day can generate about 30 MM BTUs/day using hog fuel as its feedstock. Depending on the size and efficiency of a lumber mill's boiler and kilns systems anywhere from one to six biomass pyrolysis system can be used to handle the kiln drying needs using a standard boiler system. Alternatively, the efficiency can be increased using the pyrolysis system disclosed herein in combination with heat exchange systems to provide the desired kiln temperatures.
Moreover, adapting a pyrolysis system 102 to a mill operation with a boiler system allows the mill to take advantage of the pyrolysis system's heat exchange system to support keeping the boiler system's water at temperature. It is calculated that using a pyrolysis system would reduce the boiler system's water temperature fluctuation down to 2 degrees. This reduction alone would reduce the mill's carbon footprint by 60%.
Embodiments of the present disclosure feature systems, components, and methods, for generating a nutrient-dense, organic soil amendment or topsoil substitute or soil regenerating product suitable for organic plant cultivation and other agricultural applications. In one embodiment, an organic soil amendment and/or regenerating products is formed by combining digestate solids and organic carbon in particular ratios to achieve a given, desired consistency and nutrient density. In another embodiment, a soil amendment is formed by combining digestate solids, organic carbon, and digestate liquor in particular ratios to achieve a given, desired consistency and nutrient density. In still another embodiment, a soil amendment is formed by combining digestate solids, organic carbon, digestate liquor, and additional material in particular ratios to achieve a given, desired consistency and nutrient density. The additional material may include, without limitation, soil; waste soil or soil parent material, including pulverized gravel or sand; or clean, non-putrescible landfill, sawdust, hog fuel, or other timber residual biomass. In still another embodiment, the digestate liquor alone provides a useful soil and plant amendment.
Below is a range of compositions of components in a suitable soil regenerating product.
In one embodiment of the present disclosure, a soil regeneration product includes a carbon to nitrogen ratio in the range of about 2:1 to about 40:1, and more preferably 4:1 to about 36:1
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a calcium content in the range of about 0.5 percent to about 6.8 percent, and more preferably about 1.11 to about 6.6 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a magnesium content in the range of about 0.25 to about 1.6 percent, and more preferably about 0.33 to about 1.5 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a copper content in the range of about 0.73 to about 13 mg/L, and more preferably 1.53 to about 12.03 mg/L.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a manganese content in the range of about 100 to about 350 mg/L, and more preferably about 140.2 to about 324.5 mg/L.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a nitrogen content in the range of about 0.2 to about 2 percent, and more preferably about 1.1 to about 1.7 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a phosphorous content in the range of about 0.4 to about 1.5 percent, and more preferably about 0.9 to about 1.2 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a potassium content in the range of about 0.5 to about 7 percent, and more preferably about 0.75 to about 6.5 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a sulfate content in the range of about 0.15 to about 1.4 percent, and more preferably about 0.28 to about 1.26 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a sodium content in the range of about 0.5 to about 18 percent, and more preferably about 0.14 to about 17.94 percent.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a zinc content in the range of about 55 to about 255 mg/L, and more preferably about 84 to about 233.1 mg/L.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a iron content in the range of about 600 to about 2500 mg/L, and more preferably about 695.84 to about 2385.92 mg/L.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and a boron content in the range of about 5 to about 150 mg/L, and more preferably about 6.42 to about 115.7 mg/L.
In another embodiment of the present disclosure, a soil regeneration product includes any of the foregoing or following components and has a pH in the range of about 5.4 to about 9.6.
Embodiments of the present disclosure further may include methods for remediating water by exposing said water to the organic carbon products generated by the systems described herein, and sequestering water contaminants and impurities in the organic carbon. Here organic carbon alone, or in combination with other suitable materials, such as wood chips, fines, or composted material, form a biofilter reactor through which waste water is allowed to flow at a rate sufficient to allow the water's nutrient load to be captured in the porous cells of the organic carbon. In preferred embodiments, the organic carbon comprises at least 10% of the filter, more preferably at least 20%. In another preferred embodiment, organic carbon comprises at least 50%, 70% or 100% of the filtering material in the reactor. In one embodiment the organic carbon biofilter reactor reduces waste water nutrient load by 50%. In another embodiment, it reduces the load by 60%. In still another embodiment, it reduces the load by 70% or more. Another biofilter reactor application, the organic carbon or organic carbon/woodchip combination would filter emissions from flue gas stacks of industrial furnaces.
As described above, it has been discovered that intelligent, self-governing, carbon-sequestering devices can be constructed which eliminate undesired biomass waste while producing high value bioenergy outputs or products. These devices can be useful alone or as members of a scalable, extensible, integrated, interactive and cooperative intelligent biorefinery system that mimics the behavior of natural systems.
The management of a biorefinery system 100 and its components, as described herein, requires a sophisticated control system capable of delivering the amount of heat needed for each component or member device of the system, as well as controlling the movement of biomass, gases, heat, and other products through the system. Therefore, each member device is controlled by an autonomous agent, referred to herein as a bioprocessor autonomous agent (or “BPAA”). The autonomous agents are configured to communicate with a governing agent, referred to herein as the biorefinery agent (or “BRA”), which is configured to oversee the entire production process. Adding the autonomous agent component to member devices of the system enables the entire system to be essentially “plug and play.” As more components are added to the biorefinery, the autonomous control system adapts to the added load, redistributing the flow of energy and biomass through the system. Hence, the system is referred to herein as an intelligent biorefinery system, and each member device is itself an intelligent component.
The intelligent member devices of an intelligent biorefinery system are designed to work both in concert with each other and independently. Each component has its own BPAA control system that enables it to adapt to changing environmental conditions and workloads. Multiple intelligent member devices can be interconnected via their BPAAs to form a unique intelligent biorefinery system. In that regard an intelligent biorefinery system can be tailored or adapted for use in numerous industrial or agricultural applications to make these industries and applications cleaner, more efficient, and ultimately more profitable.
For example, where remediation of contaminated water is desired, a member device could be included in an intelligent biorefinery system that is competent to receive both the contaminated water and the organic carbon output from a biomass pyrolysis system as a filter substrate. The member device's BPAA would then control the process of moving the water through the organic carbon at a rate competent to sequester the contaminants in the organic carbon. Purified water and contaminant-laden organic carbon would be outputs of the device and could be accessible to other member devices via the system, as appropriate. This member device could be designed and built specifically for the system, or an existing device could be adapted to plug into the intelligent biorefinery system simply by modifying the device so that it is competent to receive the new component. In one embodiment, the device is modified by means of an adapter that communicates between the device and the BPAA.
Another example of tailoring an intelligent biorefinery system for a given industry to improve its function is in the waste management or water treatment industries. One issue for these industries is that standard anaerobic digestion of the organic sludge or slurry does not breakdown any pharmaceuticals or hormones that may accumulate in the waste sludge. This requires heating the material to at least 600° F. Thus, a tailored intelligent biorefinery system could receive the sludge or slurry, de-water it as necessary, and add it as feedstock to an ABR to digest or breakdown the organic material. The ABR digestate output then could be dried as needed and provided as feedstock to a biomass pyrolysis device having heating capabilities sufficient to breakdown the hormones and pharmaceuticals remaining in the sludge digestate. The biomass pyrolysis output then could be returned to the earth for horticultural applications or forest remediation, as examples. Alternatively, if the treatment plant provides its own means for digesting it waste, the ABR step could be eliminated.
The intelligent biorefinery systems described herein are designed to integrate with existing industries that generate waste heat and carbon dioxide, providing a system for sequestering carbon, reclaiming the waste heat, and generating bioenergy products of value. Referring to
The BPAAs give each member device the means for solving complex nonlinear problems that can arise while attempting to maintain a stable biological environment in changing conditions. The control system also assists in the harvesting and processing of the algal biomass to produce biofuels, electricity and nitrogenous fertilizer and soil regenerating products.
Each member device of an intelligent biorefinery system, in accordance with embodiments of the present disclosure produces a bioenergy product using a process based on simple biological principles. The intelligent biorefinery system takes this concept to the next level through the use of adaptive behavioral controls that mimic natural biological processes.
The component autonomous agents or BPAAs will now be described. As mentioned above, the functionality of each component or member device of an intelligent biorefinery system is governed by an autonomous agent, such as a software agent, referred to herein as a BPAA. As illustrated in the flow chart in
The Current State Vector and the Target State Vector are composed of software objects known as Fluents. Fluents are variables that can be single valued, represent a range of values, or can be connected to a sensor to represent a measured physical parameter. For example, the Current State of a BPAA can have a fluent called “Raceway Temperature,” with a sensed value of 80° F., while the Target State can have a fluent called “Raceway Temperature” that has an interval value between 78 and 82° F., written as [78-82]. The BPAA behavior module recognizes that 80° is within the range [78-82] and so does not need to perform any actions to modify the temperature of the photobioreactor raceway. Fluents also could include Interval Valued Fluents. An example is a goal state temperature Fluent that is set for the interval range [75, 90] degrees and a current state temperature Fluent that is “sensed” at 80° F. In this case, the temperature component of the state vector would be a match.
Component behaviors can be reactive, predictive, or adaptive, or a combination of these. A reactive behavior constantly executes actions to adjust the current state to match the target state, such as opening or closing a heat exchanger valve to adjust the temperature in a component so that it matches the target state temperature. A predictive behavior might use information such as a weather forecast gathered from the Internet to begin adjusting the temperature in anticipation of a sudden cold snap. An adaptive behavior can combine predictive and reactive behaviors to generate new behaviors based on the best outcome.
The entire intelligent biorefinery system may also have its own BPAA, which has a similar structure to the member device BPAAs of the system, but is designed to oversee the system and each of the component agents. As mentioned above, such an agent is referred to herein as a governing agent or Biorefinery Agent (BRA). In this case each component agent is considered a fluent of the BRA.
Looking at the biomass pyrolysis system 102 schematic of
Target state vector information might include being on for a certain amount of time, producing a desired amount of organic carbon, utilizing a preferred feedstock, and/or generating a desired amount of heat, syngas or methane (see
Exemplary actions may include opening the methane support valve 752 to receive methane from intelligent biorefinery systems (see
The intelligent control system described herein is a fluid or dynamic integrated system rather than a static, standard control system, comprising a series of yes/no, if/then, open/close steps. These standard, or “old style” controls systems can typically be described using a simple Flow Chart or a State Machine. The intelligent control system described herein also can function using this old style paradigm, however it is also particularly designed so that the system can “discover” new behavioral patterns that lie outside of the rigid and restrictive confines of the old style controls. By contrast, a standard control system capable only of flow chart description is not competent to discover new behavior patterns.
The intelligent behavioral control system described herein is capable of both Reactive and Goal Directed behavior. The software architectural diagram shown in
Reactive behaviors are common for most control systems seen in everyday applications such as heating and cooling systems. In the intelligent control system described herein, reactive behaviors can work hand in hand with Goal Directed Behaviors to accomplish a task. An example of a simple reactive behavior would be maintaining the required temperatures in ABR reactor tanks. As temperature fluctuates the control system reacts to information supplied from a temperature sensor by opening and closing valves to maintain the optimal temperature within the tank Likewise the pH sensor data can cause the control system to react by injecting a pH buffer into the tank to balance the pH.
As implemented in the intelligent behavioral control system described herein, this simple control loop could be dynamically inserted into the “Governing Behavior & Heuristic Module” by the component Agent, referring to
The same logic can be applied to pH although the actions would be to configure the recirculation line so that it injects a pH buffer from an external tank and then turns on the circulation pump. The simple state machine or flow chart for this behavior would be similar to
Although the temperatures and pH of the system can be controlled by simple reactive behaviors as described above, the object of the ABR control system is to maximize the production of methane and/or organic soil amendments. As with most biological systems, optimal solutions are not often formulaic or closed form, as occurs in a static, standard, reactive behavior control system. Introducing Goal Directed Behavior for adaptively finding optimal solutions to the problem is an improvement over the standard means for managing behavior of multiple components that work together as part of a larger system. Introducing Goal Directed Behavior allows for the components to work as members of a community or ecosystem both with individual requirements and with a common goal.
In
Using the ABR Control system as an example we can set the Goal of the control system to maximize the production of methane in the system or to just avoid digestion failure. The goal is set using the fluents in the target state vector. By doing this, we can allow the system to discover the optimal temperatures and pH for the maximum production of methane. Although there are many variables governing the behavior of the ABR, for this example we use the pressure of the gas within the tank, the concentration of methane to carbon dioxide, the temperature and pH.
The pressure gives us an idea of how much gas is being produced, and the ratio of methane to CO2 tells us how much of that pressure is attributed to methane. Since we are working with fluents, the pressure and methane concentration can be interval valued. This allows us to set a target range and allows for a Fuzzy Solution. In addition to the optimal range we can set a critical range, outside of which an alarm will sound or shutdown condition will occur. For example, any pressures above the optimal range could be considered dangerous and should trigger a reactive behavior that will vent to atmosphere. However, the goal directed behavior should attempt to “steer” the pressure to be within the optimal range before a critical condition occurs.
For interval valued Fluents such as pressure we use the notation pressure [5, 20] meaning a range of pressures between 5 and 20 psi (pounds per square inch). If we set a goal of pressure[5, 20 ] psi and methane[60, 70 ] (a methane concentration between 60 and 70%) and allow the behavior to vary temperature and pH using the actions in the Component Action List, the behavior can “discover” the optimal range temperature and pH range. The component agent knows the goal has been met by comparing the fluents in the target state vector with those in the current state vector whereby each fluent value in the current state vector lies within interval value of the corresponding target state vector. In our example, this means that the gas pressure in the reactor tank lies somewhere between 5 psi and 15 psi and the methane concentration is between 60 and 70%.
The Agent's Behavior may indirectly discover that if the temperature is too low the acetogenic bacteria populations explode leading to the collapse of methanogenic bacterial colony resulting in elevated acidity—and that by neutralizing the acid and increasing the temperature the production of methane goes up to meet the goal. The goal directed method of controlling the component's behavior removes the need to define specific algorithmic flowcharts by allowing the behavior to “discover” which actions need to be taken to achieve the goal.
As mentioned earlier behaviors have the ability to pattern match its current state vector to data and trends stored in a relational database. The behavior can use this information to avoid conditions it has already seen and trends that can lead to colony collapse. These same principles are applied to the growth of algae within our unique photobioreactor. Once a behavioral pattern has been established the agent will continue to use the behavior as long as the current state vector and target state vector are in agreement, otherwise the agent will search for a new pattern to maintain the goal.
A simple C++ style algorithm for the agent module may look like this:
The Behavior method SelectAction( ) contains the heuristics for selecting the next action for the behavior to perform. It is perfectly acceptable for the SelectAction( ) method to return a null action that does nothing relating to the physical controls of the ABR, in which case the behavior will just leave all controls in their current state. You will note that the SelectAction( ) method takes as its input parameters the current state of the component and a reference to the database. We make no attempt to define a specific algorithm for the SelectAction method in this example since it too is an object that can be replaced by the behavior as “discovery” occurs.
Once an action has been selected, the action will be performed. As shown in
After the action has been performed the current state of the component is written to the database for future reference.
The SelectAction method is where most of the real work is done. It takes the list of actions that can be performed, the database and the current state of the component as input parameters. The main function of this method is to first search the database for a behavioral pattern that may match the recent behavior of the component. If a pattern match is found the method will then extrapolate the next action to be performed from the data. For example, if the state of the heat exchanger valve is open and the trend of pressure is moving toward the goal state then the select method may be to do nothing, otherwise the method may select the action that closes the heat exchange valve.
Below are sample tank readings of pH:
The intelligent biorefinery system design also allows a given intelligent biorefinery system to communicate with other intelligent biorefinery systems that may be local or at a distance by means of its governing behavior module, and to share that information with its member device BPAAs. For example, an intelligent biorefinery system located in Montana might be experiencing climate conditions commonly experienced in Hawaii, and which might particularly impact algal growth in the Montana intelligent biorefinery system. Using the system described herein, the Montana intelligent biorefinery system can access the Hawaii intelligent biorefinery system behavior information, and the Montana intelligent biorefinery system BPAA can utilize that solution information as part of its solution path for initiating action(s) intended to move the intelligent biorefinery systems behavior to its desired target state. Clearly, as will be understood by those skilled in the art, the Montana intelligent biorefinery system also is competent to share its behavior information with the Hawaii intelligent biorefinery system or other intelligent biorefinery systems.
This ability to communicate across systems has particular application in the embodiment where multiple intelligent biorefinery systems work together at a local industrial application. For example, one embodiment of the disclosure is an array of two or more intelligent biorefinery systems, wherein the BRA is an intelligent greenhouse. In another embodiment the greenhouse is octagonal in shape and multiple greenhouses may be arrayed in a honeycomb pattern, allowing them all to share resources, including thermally stored heat on their common side.
The BPAA intelligent process controls described herein allow one to tailor the design of an intelligent biorefinery system to a target industry with minimal programming, using a standard set of components. It also allows one to modify an existing non-intelligent device so that it can participate as an intelligent biorefinery system member device. In this case, the additional step required would be adapting, as necessary, the physical sensor and effector mechanisms so they are competent to receive information from, and effect changes on, the device.
Adaptation can be accomplished by using an adapter means that interfaces with the BPAA and the device to be modified. The adapter means provides an interface between the physical sensors and effectors on the existing “non-intelligent” device and the BPAA. The next step is to load into the software the actions that the existing device can take, and the overall goal for the device (e.g., maximize gas output, maximize digestion, minimize energy consumption). This will be dependent on the device and its particular sensors and effectors. Once this information is in place the BPAA, in cooperation and communication with other components in the control system, will find the best path for the desired goal.
Thus, the adapter means can be modified as needed to work with a wide range of currently existing devices allowing them to participate in an intelligent biorefinery system, without needing to substantially modify the intelligent biorefinery system itself or to re-design or build whole devices anew. Thus, a “plug-in-and-play” intelligent, carbon-sequestering intelligent biorefinery system now is available for use in multiple different industries. In the lumber mill example described above, if one wanted to include the mill's boiler as part of an intelligent biorefinery system, such an adapter means might include sensors for measuring water temperature, and effectors for modulating the quantity of heat provided to the boiler.
In accordance with aspects of the present disclosure, the systems described herein may be intelligent biorefinery systems. Intelligent biorefinery systems are interactive systems including integrated, cooperatively-acting member devices and which may use artificial intelligence to (1) govern the behavior of each member device autonomously, and (2) communicate that behavior to one or more other member devices through an autonomous agent that acts as a governing agent. In that regard the behaviors of the member devices and the system itself are designed such that the member devices function cooperatively, modulating their individual inputs and outputs based on the needs of the system.
In accordance with aspects of the present disclosure, each member device is itself an autonomous agent, which may be competent to (1) perceive the current state of the member device, using sensors and effectors, respectively, to perceive and act on its environment; (2) identify a target state based on input from its local environment and other resources including, without limitation, databases, other systems or devices in other locations, and/or a governing agent; (3) initiate action(s) intended to modify the member device's behavior towards the desired target state; and (4) evaluate the success or failure of initiated actions in achieving the target state, and make changes accordingly.
In accordance with aspects of the present disclosure, the autonomous agent includes in its solution process the outcomes of previous solution pathways sought, effectively continually “learning.” In another aspect, the autonomous agent mimics nature's own process for continually evolving and adapting to changes in the environment, dynamically balancing inputs and outputs while discovering the “best” process for achieving a desired result. In other aspects, the autonomous agent utilizes a goal-directed behavior model as part of its solution process. In another aspect, the autonomous agent utilizes a heuristic algorithm or function as part of its solution path. In still another aspect, the autonomous agent utilizes fluents as part of the process of understanding its current and target states, and/or as a means for (1) communicating computed actions to effectors in the external environment, and (2) communicating the state of the external environment to the autonomous agent perceived through one or more sensors.
In accordance with aspects of the present disclosure, the autonomous agents of the intelligent biorefinery system member devices may have a common architecture and structure, allowing the member devices to easily plug into or out of the system as needed, enhancing the portability and extendability of the intelligent biorefinery system, as well as its modification for multiple, different industries or applications.
In accordance with aspects of the present disclosure, the PBR autonomous agent acts as a system's Governing Agent. In still another aspect, the facility or structure that houses the member devices (e.g., the greenhouse system) may act as a Governing Agent. In another aspect, the greenhouse system has value as a functional greenhouse.
In another aspect, the embodiments of the disclosure feature intelligent components, each of which includes an autonomous agent as described herein.
Preferred algal biomass volumes to be delivered to the ABR, and harvested from the ABR will depend on the algae species used, the species of digestive bacteria, and the size of the digester tanks selected. Those of ordinary skill in the art will be able to determine ideal volumes and retention times without undue experimentation. Where smaller volumes are provided and harvested, bacteria recovery typically is faster as a larger population is retained in the tank. In a preferred embodiment, the ratio of retention time in an acetogenic tank to a methanogenic tank is 1:2, and the ratio of retention time in the concentrator tank to the hydrolysis tank is 1:3. In another preferred embodiment, retention time in each of the hydrolysis tank and the acetogenesis tank is at least 3 days and not more than 5 days.
Applications such as the core controller agent application and the ABR agent application depicted in
Various embodiments of control software and/or circuitry described herein can be used in combination with a diverse array of sensors that can give a refined minute-by-minute view of the state of the system. An autonomous network optimizer can be used to provide an interface between sensor data and control feedback so that each system component can query other components in order to optimally adjust its own state. The autonomous component optimizer can be implemented in software, hardware, or a combination of hardware and software.
The autonomous component optimizer manages the process within each component and manages the flow of materials, energy and information between the components. The autonomous component optimizer makes the example embodiment of the biorefinery system scalable and extensible, and can provide similar benefits to other systems. For example, the autonomous component optimizer can be used to manage a high load of nitrogen and phosphorus in the effluent coming from a waste water treatment plant. The autonomous component optimizer allows creation of adaptors so that another manufacturer's components can be more easily integrated into the system. An example of this would be another bioreactor designed to digest the effluent from a dairy farm. The adaptor would translate the dairy farm bioreactor's behavior into one that easily integrates into the system.
A symbolic representation of the autonomous component optimizer bus is shown in
Maintaining the optimal state of a component, such as the PBR, ABR or biomass pyrolysis system, requires monitoring and regulating the flow of materials and energy through the component. Beyond simple controls that just react to the changing state of a component are controls that anticipate what will be needed by a component and send messages to other components to prepare the required materials. One goal of a component may be to maximize the output of some material (e.g., algae, electricity, fertilizer, or some other byproduct needed by another component) while minimizing energy consumption. In at least one embodiment, messages are sent to remote pumps, valves, and actuators, and information is collected from an array of sensors. The collected information is sent to a software agent or multiple agents that make decisions about what to do next.
Autonomous agents described herein can be used to enhance the functionality of components of facilities other than biorefineries, including wastewater treatment plants, cement plants, a dairy farms, and coal plants. Such components can include sensors and effectors that exist in the facilities or that may be added within the facilities. Referring again to
Autonomous agents also can facilitate integration of separate facilities. For example, BPAAs can integrate management of a biorefinery with management of facilities such as a waste water treatment plant (
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The ability of a described biorefinery system to consume waste heat and also generate electricity may be especially useful in a data center/server farm context, given the amount of heat that is generated by the servers and the power that is needed to keep them cool. For example, as shown in
Embodiments of the disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the disclosure.
This application is a continuation of application Ser. No. 13/951296, filed Jul. 25, 2013, which claims the benefit of U.S. Provisional Application No. 61/780842, filed Mar. 13, 2013, and U.S. Provisional Application No. 61/675766, filed Jul. 25, 2012, the disclosures of which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61780842 | Mar 2013 | US | |
| 61675766 | Jul 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13951296 | Jul 2013 | US |
| Child | 15944329 | US |
